Merge branch 'safe-search'

pom.xml

@@ -99,6 +99,10 @@
       <groupId>io.net5</groupId>
       <artifactId>netty-buffer</artifactId>
     </dependency>
+    <dependency>
+      <groupId>io.net5.incubator</groupId>
+      <artifactId>netty-incubator-buffer-memseg</artifactId>
+    </dependency>
     <dependency>
       <groupId>javax.xml.bind</groupId>
       <artifactId>jaxb-api</artifactId>
@@ -168,6 +172,11 @@
       <artifactId>log4j-slf4j-impl</artifactId>
       <scope>test</scope>
     </dependency>
+    <dependency>
+      <groupId>com.lmax</groupId>
+      <artifactId>disruptor</artifactId>
+      <version>3.3.4</version>
+    </dependency>
     <dependency>
       <groupId>org.rocksdb</groupId>
       <artifactId>rocksdbjni</artifactId>
@@ -266,6 +275,11 @@
         <artifactId>netty-buffer</artifactId>
         <version>5.0.0.Final-SNAPSHOT</version>
       </dependency>
+      <dependency>
+        <groupId>io.net5.incubator</groupId>
+        <artifactId>netty-incubator-buffer-memseg</artifactId>
+        <version>0.0.1.Final-SNAPSHOT</version>
+      </dependency>
       <dependency>
         <groupId>javax.xml.bind</groupId>
         <artifactId>jaxb-api</artifactId>
@@ -343,6 +357,11 @@
         <artifactId>log4j-slf4j-impl</artifactId>
         <version>2.14.1</version>
       </dependency>
+      <dependency>
+        <groupId>com.lmax</groupId>
+        <artifactId>disruptor</artifactId>
+        <scope>test</scope>
+      </dependency>
       <dependency>
         <groupId>org.rocksdb</groupId>
         <artifactId>rocksdbjni</artifactId>
@@ -484,7 +503,7 @@
         <artifactId>maven-compiler-plugin</artifactId>
         <version>3.8.1</version>
         <configuration>
-          <release>16</release>
+          <release>17</release>
           <annotationProcessorPaths>
             <annotationProcessorPath>
               <groupId>io.soabase.record-builder</groupId>
@@ -499,8 +518,8 @@
           <compilerArgs>--enable-preview
             <arg>--add-opens=java.base/jdk.internal.misc=ALL-UNNAMED</arg>
           </compilerArgs>
-          <source>16</source>
+          <source>17</source>
-          <target>16</target>
+          <target>17</target>
         </configuration>
       </plugin>
       <plugin>
@@ -533,7 +552,7 @@
           </dependency>
         </dependencies>
         <configuration>
-          <argLine>--enable-preview --add-modules jdk.incubator.foreign -Dforeign.restricted=permit --add-opens=java.base/jdk.internal.misc=ALL-UNNAMED</argLine>
+          <argLine>--enable-preview --add-modules jdk.incubator.foreign -Dforeign.restricted=permit --add-opens=java.base/jdk.internal.misc=ALL-UNNAMED --enable-native-access=ALL-UNNAMED</argLine>
           <systemProperties>
             <property>
               <name>ci</name>

src/main/java/it/cavallium/dbengine/client/LuceneIndex.java

@@ -1,5 +1,6 @@
 package it.cavallium.dbengine.client;
 
+import io.net5.buffer.api.Send;
 import it.cavallium.dbengine.client.query.ClientQueryParams;
 import it.cavallium.dbengine.client.query.current.data.Query;
 import it.cavallium.dbengine.client.query.current.data.TotalHitsCount;
@@ -52,9 +53,9 @@ public interface LuceneIndex<T, U> extends LLSnapshottable {
 
 	Mono<Void> deleteAll();
 
-	Mono<SearchResultKeys<T>> moreLikeThis(ClientQueryParams<SearchResultKey<T>> queryParams, T key, U mltDocumentValue);
+	Mono<Send<SearchResultKeys<T>>> moreLikeThis(ClientQueryParams<SearchResultKey<T>> queryParams, T key, U mltDocumentValue);
 
-	default Mono<SearchResult<T, U>> moreLikeThisWithValues(ClientQueryParams<SearchResultItem<T, U>> queryParams,
+	default Mono<Send<SearchResult<T, U>>> moreLikeThisWithValues(ClientQueryParams<SearchResultItem<T, U>> queryParams,
 			T key,
 			U mltDocumentValue,
 			ValueGetter<T, U> valueGetter) {
@@ -64,21 +65,19 @@ public interface LuceneIndex<T, U> extends LLSnapshottable {
 				getValueGetterTransformer(valueGetter));
 	}
 
-	Mono<SearchResult<T, U>> moreLikeThisWithTransformer(ClientQueryParams<SearchResultItem<T, U>> queryParams,
+	Mono<Send<SearchResult<T, U>>> moreLikeThisWithTransformer(ClientQueryParams<SearchResultItem<T, U>> queryParams,
 			T key,
 			U mltDocumentValue,
 			ValueTransformer<T, U> valueTransformer);
 
-	Mono<SearchResultKeys<T>> search(ClientQueryParams<SearchResultKey<T>> queryParams);
+	Mono<Send<SearchResultKeys<T>>> search(ClientQueryParams<SearchResultKey<T>> queryParams);
 
-	default Mono<SearchResult<T, U>> searchWithValues(ClientQueryParams<SearchResultItem<T, U>> queryParams,
+	default Mono<Send<SearchResult<T, U>>> searchWithValues(ClientQueryParams<SearchResultItem<T, U>> queryParams,
 			ValueGetter<T, U> valueGetter) {
-		return this.searchWithTransformer(queryParams,
+		return this.searchWithTransformer(queryParams, getValueGetterTransformer(valueGetter));
-				getValueGetterTransformer(valueGetter)
-		);
 	}
 
-	Mono<SearchResult<T, U>> searchWithTransformer(ClientQueryParams<SearchResultItem<T, U>> queryParams,
+	Mono<Send<SearchResult<T, U>>> searchWithTransformer(ClientQueryParams<SearchResultItem<T, U>> queryParams,
 			ValueTransformer<T, U> valueTransformer);
 
 	Mono<TotalHitsCount> count(@Nullable CompositeSnapshot snapshot, Query query);

src/main/java/it/cavallium/dbengine/client/LuceneIndexImpl.java

@@ -1,5 +1,6 @@
 package it.cavallium.dbengine.client;
 
+import io.net5.buffer.api.Send;
 import it.cavallium.dbengine.client.query.ClientQueryParams;
 import it.cavallium.dbengine.client.query.current.data.Query;
 import it.cavallium.dbengine.client.query.current.data.TotalHitsCount;
@@ -84,24 +85,38 @@ public class LuceneIndexImpl<T, U> implements LuceneIndex<T, U> {
 		return luceneIndex.deleteAll();
 	}
 
-	private Mono<SearchResultKeys<T>> transformLuceneResultWithTransformer(LLSearchResultShard llSearchResult) {
+	private Mono<Send<SearchResultKeys<T>>> transformLuceneResultWithTransformer(
-		return Mono.just(new SearchResultKeys<>(llSearchResult.results()
+			Mono<Send<LLSearchResultShard>> llSearchResultMono) {
-				.map(signal -> new SearchResultKey<>(Mono.fromCallable(signal::key).map(indicizer::getKey), signal.score())),
+		return llSearchResultMono.map(llSearchResultToReceive -> {
+			var llSearchResult = llSearchResultToReceive.receive();
+			return new SearchResultKeys<>(llSearchResult.results()
+					.map(signal -> new SearchResultKey<>(Mono
+							.fromCallable(signal::key)
+							.map(indicizer::getKey), signal.score())),
 					llSearchResult.totalHitsCount(),
-				llSearchResult.release()
+					d -> llSearchResult.close()
-		));
+			).send();
+		});
 	}
 
-	private Mono<SearchResult<T, U>> transformLuceneResultWithValues(LLSearchResultShard llSearchResult,
+	private Mono<Send<SearchResult<T, U>>> transformLuceneResultWithValues(
+			Mono<Send<LLSearchResultShard>> llSearchResultMono,
 			ValueGetter<T, U> valueGetter) {
-		return Mono.fromCallable(() -> new SearchResult<>(llSearchResult.results().map(signal -> {
+		return llSearchResultMono.map(llSearchResultToReceive -> {
+			var llSearchResult = llSearchResultToReceive.receive();
+			return new SearchResult<>(llSearchResult.results().map(signal -> {
 				var key = Mono.fromCallable(signal::key).map(indicizer::getKey);
 				return new SearchResultItem<>(key, key.flatMap(valueGetter::get), signal.score());
-		}), llSearchResult.totalHitsCount(), llSearchResult.release()));
+			}), llSearchResult.totalHitsCount(), d -> llSearchResult.close()).send();
+		});
 	}
 
-	private Mono<SearchResult<T, U>> transformLuceneResultWithTransformer(LLSearchResultShard llSearchResult,
+	private Mono<Send<SearchResult<T, U>>> transformLuceneResultWithTransformer(
+			Mono<Send<LLSearchResultShard>> llSearchResultMono,
 			ValueTransformer<T, U> valueTransformer) {
+		return llSearchResultMono
+				.map(llSearchResultToReceive -> {
+					var llSearchResult = llSearchResultToReceive.receive();
 					var scoresWithKeysFlux = llSearchResult
 							.results()
 							.flatMapSequential(signal -> Mono
@@ -116,26 +131,27 @@ public class LuceneIndexImpl<T, U> implements LuceneIndex<T, U> {
 									Mono.just(tuple3.getT3().orElseThrow()),
 									tuple3.getT1()
 							));
-		return Mono.fromCallable(() -> new SearchResult<>(resultItemsFlux,
+					return new SearchResult<>(resultItemsFlux,
 							llSearchResult.totalHitsCount(),
-				llSearchResult.release()
+							d -> llSearchResult.close()
-		));
+					).send();
+				});
 	}
 
 	@Override
-	public Mono<SearchResultKeys<T>> moreLikeThis(ClientQueryParams<SearchResultKey<T>> queryParams,
+	public Mono<Send<SearchResultKeys<T>>> moreLikeThis(ClientQueryParams<SearchResultKey<T>> queryParams,
 			T key,
 			U mltDocumentValue) {
 		Flux<Tuple2<String, Set<String>>> mltDocumentFields
 				= indicizer.getMoreLikeThisDocumentFields(key, mltDocumentValue);
 		return luceneIndex
 				.moreLikeThis(resolveSnapshot(queryParams.snapshot()), queryParams.toQueryParams(), indicizer.getKeyFieldName(), mltDocumentFields)
-				.flatMap(this::transformLuceneResultWithTransformer);
+				.transform(this::transformLuceneResultWithTransformer);
 
 	}
 
 	@Override
-	public Mono<SearchResult<T, U>> moreLikeThisWithValues(ClientQueryParams<SearchResultItem<T, U>> queryParams,
+	public Mono<Send<SearchResult<T, U>>> moreLikeThisWithValues(ClientQueryParams<SearchResultItem<T, U>> queryParams,
 			T key,
 			U mltDocumentValue,
 			ValueGetter<T, U> valueGetter) {
@@ -147,13 +163,12 @@ public class LuceneIndexImpl<T, U> implements LuceneIndex<T, U> {
 						indicizer.getKeyFieldName(),
 						mltDocumentFields
 				)
-				.flatMap(llSearchResult -> this.transformLuceneResultWithValues(llSearchResult,
+				.transform(llSearchResult -> this.transformLuceneResultWithValues(llSearchResult,
-						valueGetter
+						valueGetter));
-				));
 	}
 
 	@Override
-	public Mono<SearchResult<T, U>> moreLikeThisWithTransformer(ClientQueryParams<SearchResultItem<T, U>> queryParams,
+	public Mono<Send<SearchResult<T, U>>> moreLikeThisWithTransformer(ClientQueryParams<SearchResultItem<T, U>> queryParams,
 			T key,
 			U mltDocumentValue,
 			ValueTransformer<T, U> valueTransformer) {
@@ -165,40 +180,51 @@ public class LuceneIndexImpl<T, U> implements LuceneIndex<T, U> {
 						indicizer.getKeyFieldName(),
 						mltDocumentFields
 				)
-				.flatMap(llSearchResult -> this.transformLuceneResultWithTransformer(llSearchResult, valueTransformer));
+				.transform(llSearchResult -> this.transformLuceneResultWithTransformer(llSearchResult,
+						valueTransformer));
 	}
 
 	@Override
-	public Mono<SearchResultKeys<T>> search(ClientQueryParams<SearchResultKey<T>> queryParams) {
+	public Mono<Send<SearchResultKeys<T>>> search(ClientQueryParams<SearchResultKey<T>> queryParams) {
 		return luceneIndex
 				.search(resolveSnapshot(queryParams.snapshot()),
 						queryParams.toQueryParams(),
 						indicizer.getKeyFieldName()
 				)
-				.flatMap(this::transformLuceneResultWithTransformer);
+				.transform(this::transformLuceneResultWithTransformer);
 	}
 
 	@Override
-	public Mono<SearchResult<T, U>> searchWithValues(ClientQueryParams<SearchResultItem<T, U>> queryParams,
+	public Mono<Send<SearchResult<T, U>>> searchWithValues(
+			ClientQueryParams<SearchResultItem<T, U>> queryParams,
 			ValueGetter<T, U> valueGetter) {
 		return luceneIndex
-				.search(resolveSnapshot(queryParams.snapshot()), queryParams.toQueryParams(), indicizer.getKeyFieldName())
+				.search(resolveSnapshot(queryParams.snapshot()), queryParams.toQueryParams(),
-				.flatMap(llSearchResult -> this.transformLuceneResultWithValues(llSearchResult, valueGetter));
+						indicizer.getKeyFieldName())
+				.transform(llSearchResult -> this.transformLuceneResultWithValues(llSearchResult,
+						valueGetter));
 	}
 
 	@Override
-	public Mono<SearchResult<T, U>> searchWithTransformer(ClientQueryParams<SearchResultItem<T, U>> queryParams,
+	public Mono<Send<SearchResult<T, U>>> searchWithTransformer(
+			ClientQueryParams<SearchResultItem<T, U>> queryParams,
 			ValueTransformer<T, U> valueTransformer) {
 		return luceneIndex
-				.search(resolveSnapshot(queryParams.snapshot()), queryParams.toQueryParams(), indicizer.getKeyFieldName())
+				.search(resolveSnapshot(queryParams.snapshot()), queryParams.toQueryParams(),
-				.flatMap(llSearchResult -> this.transformLuceneResultWithTransformer(llSearchResult, valueTransformer));
+						indicizer.getKeyFieldName())
+				.transform(llSearchResult -> this.transformLuceneResultWithTransformer(llSearchResult,
+						valueTransformer));
 	}
 
 	@Override
 	public Mono<TotalHitsCount> count(@Nullable CompositeSnapshot snapshot, Query query) {
 		return this
 				.search(ClientQueryParams.<SearchResultKey<T>>builder().snapshot(snapshot).query(query).limit(0).build())
-				.flatMap(tSearchResultKeys -> tSearchResultKeys.release().thenReturn(tSearchResultKeys.totalHitsCount()));
+				.map(searchResultKeysSend -> {
+					try (var searchResultKeys = searchResultKeysSend.receive()) {
+						return searchResultKeys.totalHitsCount();
+					}
+				});
 	}
 
 	@Override

src/main/java/it/cavallium/dbengine/client/MappedSerializer.java

@@ -5,6 +5,7 @@ import io.net5.buffer.api.Send;
 import it.cavallium.dbengine.database.serialization.SerializationException;
 import it.cavallium.dbengine.database.serialization.Serializer;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
 public class MappedSerializer<A, B> implements Serializer<B> {
 

src/main/java/it/cavallium/dbengine/client/MappedSerializerFixedLength.java

@@ -5,6 +5,7 @@ import io.net5.buffer.api.Send;
 import it.cavallium.dbengine.database.serialization.SerializationException;
 import it.cavallium.dbengine.database.serialization.SerializerFixedBinaryLength;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
 public class MappedSerializerFixedLength<A, B> implements SerializerFixedBinaryLength<B> {
 

src/main/java/it/cavallium/dbengine/client/SearchResult.java

@@ -1,42 +1,31 @@
 package it.cavallium.dbengine.client;
 
+import io.net5.buffer.api.Drop;
+import io.net5.buffer.api.Owned;
+import io.net5.buffer.api.internal.ResourceSupport;
 import it.cavallium.dbengine.client.query.current.data.TotalHitsCount;
 import it.cavallium.dbengine.database.LLSearchResultShard;
+import it.cavallium.dbengine.database.LiveResourceSupport;
 import java.util.Objects;
 import org.warp.commonutils.log.Logger;
 import org.warp.commonutils.log.LoggerFactory;
 import reactor.core.publisher.Flux;
 import reactor.core.publisher.Mono;
 
-public final class SearchResult<T, U> {
+public final class SearchResult<T, U> extends LiveResourceSupport<SearchResult<T, U>, SearchResult<T, U>> {
 
-	private static final Logger logger = LoggerFactory.getLogger(SearchResult.class);
+	private Flux<SearchResultItem<T, U>> results;
+	private TotalHitsCount totalHitsCount;
 
-	private volatile boolean releaseCalled;
+	public SearchResult(Flux<SearchResultItem<T, U>> results, TotalHitsCount totalHitsCount,
-
+			Drop<SearchResult<T, U>> drop) {
-	private final Flux<SearchResultItem<T, U>> results;
+		super(drop);
-	private final TotalHitsCount totalHitsCount;
-	private final Mono<Void> release;
-
-	public SearchResult(Flux<SearchResultItem<T, U>> results, TotalHitsCount totalHitsCount, Mono<Void> release) {
 		this.results = results;
 		this.totalHitsCount = totalHitsCount;
-		this.release = Mono.fromRunnable(() -> {
-			if (releaseCalled) {
-				logger.warn(this.getClass().getName() + "::release has been called twice!");
-			}
-			releaseCalled = true;
-		}).then(release);
 	}
 
 	public static <T, U> SearchResult<T, U> empty() {
-		var sr = new SearchResult<T, U>(Flux.empty(), TotalHitsCount.of(0, true), Mono.empty());
+		return new SearchResult<T, U>(Flux.empty(), TotalHitsCount.of(0, true), d -> {});
-		sr.releaseCalled = true;
-		return sr;
-	}
-
-	public Flux<SearchResultItem<T, U>> resultsThenRelease() {
-		return Flux.usingWhen(Mono.just(true), _unused -> results, _unused -> release);
 	}
 
 	public Flux<SearchResultItem<T, U>> results() {
@@ -47,39 +36,25 @@ public final class SearchResult<T, U> {
 		return totalHitsCount;
 	}
 
-	public Mono<Void> release() {
-		return release;
-	}
-
-	@Override
-	public boolean equals(Object obj) {
-		if (obj == this)
-			return true;
-		if (obj == null || obj.getClass() != this.getClass())
-			return false;
-		var that = (SearchResult) obj;
-		return Objects.equals(this.results, that.results) && Objects.equals(this.totalHitsCount, that.totalHitsCount)
-				&& Objects.equals(this.release, that.release);
-	}
-
-	@Override
-	public int hashCode() {
-		return Objects.hash(results, totalHitsCount, release);
-	}
-
 	@Override
 	public String toString() {
-		return "SearchResult[" + "results=" + results + ", " + "totalHitsCount=" + totalHitsCount + ", " + "release="
+		return "SearchResult[" + "results=" + results + ", " + "totalHitsCount=" + totalHitsCount + ']';
-				+ release + ']';
 	}
 
-	@SuppressWarnings("deprecation")
 	@Override
-	protected void finalize() throws Throwable {
+	protected RuntimeException createResourceClosedException() {
-		if (!releaseCalled) {
+		return new IllegalStateException("Closed");
-			logger.warn(this.getClass().getName() + "::release has not been called before class finalization!");
-		}
-		super.finalize();
 	}
 
+	@Override
+	protected Owned<SearchResult<T, U>> prepareSend() {
+		var results = this.results;
+		var totalHitsCount = this.totalHitsCount;
+		return drop -> new SearchResult<>(results, totalHitsCount, drop);
+	}
+
+	protected void makeInaccessible() {
+		this.results = null;
+		this.totalHitsCount = null;
+	}
 }

src/main/java/it/cavallium/dbengine/client/SearchResultKeys.java

@@ -1,7 +1,11 @@
 package it.cavallium.dbengine.client;
 
+import io.net5.buffer.api.Drop;
+import io.net5.buffer.api.Owned;
+import io.net5.buffer.api.internal.ResourceSupport;
 import it.cavallium.dbengine.client.query.current.data.TotalHitsCount;
 import it.cavallium.dbengine.database.LLSearchResultShard;
+import it.cavallium.dbengine.database.LiveResourceSupport;
 import it.cavallium.dbengine.database.collections.ValueGetter;
 import java.util.Objects;
 import org.reactivestreams.Publisher;
@@ -11,42 +15,29 @@ import reactor.core.publisher.Flux;
 import reactor.core.publisher.Mono;
 
 @SuppressWarnings("unused")
-public final class SearchResultKeys<T> {
+public final class SearchResultKeys<T> extends LiveResourceSupport<SearchResultKeys<T>, SearchResultKeys<T>> {
 
 	private static final Logger logger = LoggerFactory.getLogger(SearchResultKeys.class);
 
-	private volatile boolean releaseCalled;
+	private Flux<SearchResultKey<T>> results;
+	private TotalHitsCount totalHitsCount;
 
-	private final Flux<SearchResultKey<T>> results;
+	public SearchResultKeys(Flux<SearchResultKey<T>> results, TotalHitsCount totalHitsCount,
-	private final TotalHitsCount totalHitsCount;
+			Drop<SearchResultKeys<T>> drop) {
-	private final Mono<Void> release;
+		super(drop);
-
-	public SearchResultKeys(Flux<SearchResultKey<T>> results, TotalHitsCount totalHitsCount, Mono<Void> release) {
 		this.results = results;
 		this.totalHitsCount = totalHitsCount;
-		this.release = Mono.fromRunnable(() -> {
-			if (releaseCalled) {
-				logger.warn(this.getClass().getName() + "::release has been called twice!");
-			}
-			releaseCalled = true;
-		}).then(release);
 	}
 
 	public static <T> SearchResultKeys<T> empty() {
-		var sr = new SearchResultKeys<T>(Flux.empty(), TotalHitsCount.of(0, true), Mono.empty());
+		return new SearchResultKeys<T>(Flux.empty(), TotalHitsCount.of(0, true), d -> {});
-		sr.releaseCalled = true;
-		return sr;
 	}
 
 	public <U> SearchResult<T, U> withValues(ValueGetter<T, U> valuesGetter) {
 		return new SearchResult<>(results.map(item -> new SearchResultItem<>(item.key(),
 				item.key().flatMap(valuesGetter::get),
 				item.score()
-		)), totalHitsCount, release);
+		)), totalHitsCount, d -> this.close());
-	}
-
-	public Flux<SearchResultKey<T>> resultsThenRelease() {
-		return Flux.usingWhen(Mono.just(true), _unused -> results, _unused -> release);
 	}
 
 	public Flux<SearchResultKey<T>> results() {
@@ -57,39 +48,27 @@ public final class SearchResultKeys<T> {
 		return totalHitsCount;
 	}
 
-	public Mono<Void> release() {
-		return release;
-	}
-
-	@Override
-	public boolean equals(Object obj) {
-		if (obj == this)
-			return true;
-		if (obj == null || obj.getClass() != this.getClass())
-			return false;
-		var that = (SearchResultKeys) obj;
-		return Objects.equals(this.results, that.results) && Objects.equals(this.totalHitsCount, that.totalHitsCount)
-				&& Objects.equals(this.release, that.release);
-	}
-
-	@Override
-	public int hashCode() {
-		return Objects.hash(results, totalHitsCount, release);
-	}
-
 	@Override
 	public String toString() {
-		return "SearchResultKeys[" + "results=" + results + ", " + "totalHitsCount=" + totalHitsCount + ", " + "release="
+		return "SearchResultKeys[" + "results=" + results + ", " + "totalHitsCount=" + totalHitsCount + ']';
-				+ release + ']';
 	}
 
-	@SuppressWarnings("deprecation")
 	@Override
-	protected void finalize() throws Throwable {
+	protected RuntimeException createResourceClosedException() {
-		if (!releaseCalled) {
+		return new IllegalStateException("Closed");
-			logger.warn(this.getClass().getName() + "::release has not been called before class finalization!");
 	}
-		super.finalize();
+
+	@Override
+	protected Owned<SearchResultKeys<T>> prepareSend() {
+		var results = this.results;
+		var totalHitsCount = this.totalHitsCount;
+		makeInaccessible();
+		return drop -> new SearchResultKeys<>(results, totalHitsCount, drop);
+	}
+
+	protected void makeInaccessible() {
+		this.results = null;
+		this.totalHitsCount = null;
 	}
 
 }

src/main/java/it/cavallium/dbengine/database/LLDelta.java

@@ -8,7 +8,7 @@ import io.net5.buffer.api.internal.ResourceSupport;
 import java.util.StringJoiner;
 import org.jetbrains.annotations.Nullable;
 
-public class LLDelta extends ResourceSupport<LLDelta, LLDelta> {
+public class LLDelta extends LiveResourceSupport<LLDelta, LLDelta> {
 	@Nullable
 	private final Buffer previous;
 	@Nullable

src/main/java/it/cavallium/dbengine/database/LLEntry.java

@@ -7,14 +7,15 @@ import io.net5.buffer.api.Send;
 import io.net5.buffer.api.internal.ResourceSupport;
 import java.util.StringJoiner;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
-public class LLEntry extends ResourceSupport<LLEntry, LLEntry> {
+public class LLEntry extends LiveResourceSupport<LLEntry, LLEntry> {
 	@NotNull
 	private final Buffer key;
 	@NotNull
 	private final Buffer value;
 
-	private LLEntry(Send<Buffer> key, Send<Buffer> value, Drop<LLEntry> drop) {
+	private LLEntry(@NotNull Send<Buffer> key, @NotNull Send<Buffer> value, Drop<LLEntry> drop) {
 		super(new LLEntry.CloseOnDrop(drop));
 		this.key = key.receive().makeReadOnly();
 		this.value = value.receive().makeReadOnly();
@@ -29,7 +30,7 @@ public class LLEntry extends ResourceSupport<LLEntry, LLEntry> {
 		return true;
 	}
 
-	public static LLEntry of(Send<Buffer> key, Send<Buffer> value) {
+	public static LLEntry of(@NotNull Send<Buffer> key, @NotNull Send<Buffer> value) {
 		return new LLEntry(key, value, d -> {});
 	}
 

src/main/java/it/cavallium/dbengine/database/LLLuceneIndex.java

@@ -1,5 +1,6 @@
 package it.cavallium.dbengine.database;
 
+import io.net5.buffer.api.Send;
 import it.cavallium.data.generator.nativedata.Nullablefloat;
 import it.cavallium.dbengine.client.query.current.data.NoSort;
 import it.cavallium.dbengine.client.query.current.data.Query;
@@ -40,7 +41,7 @@ public interface LLLuceneIndex extends LLSnapshottable {
 	 *                    The additional query will be used with the moreLikeThis query: "mltQuery AND additionalQuery"
 	 * @return the collection has one or more flux
 	 */
-	Mono<LLSearchResultShard> moreLikeThis(@Nullable LLSnapshot snapshot,
+	Mono<Send<LLSearchResultShard>> moreLikeThis(@Nullable LLSnapshot snapshot,
 			QueryParams queryParams,
 			String keyFieldName,
 			Flux<Tuple2<String, Set<String>>> mltDocumentFields);
@@ -50,13 +51,18 @@ public interface LLLuceneIndex extends LLSnapshottable {
 	 *                    returned can be at most <code>limit * 15</code>
 	 * @return the collection has one or more flux
 	 */
-	Mono<LLSearchResultShard> search(@Nullable LLSnapshot snapshot, QueryParams queryParams, String keyFieldName);
+	Mono<Send<LLSearchResultShard>> search(@Nullable LLSnapshot snapshot, QueryParams queryParams, String keyFieldName);
 
 	default Mono<TotalHitsCount> count(@Nullable LLSnapshot snapshot, Query query) {
 		QueryParams params = QueryParams.of(query, 0, 0, Nullablefloat.empty(), NoSort.of(), ScoreMode.of(false, false));
 		return Mono.from(this.search(snapshot, params, null)
-				.flatMap(llSearchResultShard -> llSearchResultShard.release().thenReturn(llSearchResultShard.totalHitsCount()))
+				.map(llSearchResultShardToReceive -> {
-				.defaultIfEmpty(TotalHitsCount.of(0, true)));
+					try (var llSearchResultShard = llSearchResultShardToReceive.receive()) {
+						return llSearchResultShard.totalHitsCount();
+					}
+				})
+				.defaultIfEmpty(TotalHitsCount.of(0, true))
+		).doOnDiscard(Send.class, Send::close);
 	}
 
 	boolean isLowMemoryMode();

src/main/java/it/cavallium/dbengine/database/LLRange.java

@@ -12,7 +12,7 @@ import java.util.StringJoiner;
 /**
  * Range of data, from min (inclusive),to max (exclusive)
  */
-public class LLRange extends ResourceSupport<LLRange, LLRange> {
+public class LLRange extends LiveResourceSupport<LLRange, LLRange> {
 
 	private static final LLRange RANGE_ALL = new LLRange(null, null, null, d -> {});
 	private Buffer min;
@@ -193,11 +193,10 @@ public class LLRange extends ResourceSupport<LLRange, LLRange> {
 		minSend = this.min != null ? this.min.send() : null;
 		maxSend = this.max != null ? this.max.send() : null;
 		singleSend = this.single != null ? this.single.send() : null;
-		this.makeInaccessible();
 		return drop -> new LLRange(minSend, maxSend, singleSend, drop);
 	}
 
-	private void makeInaccessible() {
+	protected void makeInaccessible() {
 		this.min = null;
 		this.max = null;
 		this.single = null;
@@ -213,10 +212,9 @@ public class LLRange extends ResourceSupport<LLRange, LLRange> {
 
 		@Override
 		public void drop(LLRange obj) {
-			if (obj.min != null) obj.min.close();
+			if (obj.min != null && obj.min.isAccessible()) obj.min.close();
-			if (obj.max != null) obj.max.close();
+			if (obj.max != null && obj.max.isAccessible()) obj.max.close();
-			if (obj.single != null) obj.single.close();
+			if (obj.single != null && obj.single.isAccessible()) obj.single.close();
-			obj.makeInaccessible();
 			delegate.drop(obj);
 		}
 	}

src/main/java/it/cavallium/dbengine/database/LLSearchResultShard.java

@@ -1,44 +1,39 @@
 package it.cavallium.dbengine.database;
 
+import io.net5.buffer.api.Drop;
+import io.net5.buffer.api.Owned;
+import io.net5.buffer.api.internal.ResourceSupport;
 import it.cavallium.dbengine.client.query.current.data.TotalHitsCount;
-import it.cavallium.dbengine.lucene.searcher.LuceneSearchResult;
 import java.util.Objects;
 import org.warp.commonutils.log.Logger;
 import org.warp.commonutils.log.LoggerFactory;
 import reactor.core.publisher.Flux;
-import reactor.core.publisher.Mono;
 
-public final class LLSearchResultShard {
+public final class LLSearchResultShard extends LiveResourceSupport<LLSearchResultShard, LLSearchResultShard> {
 
 	private static final Logger logger = LoggerFactory.getLogger(LLSearchResultShard.class);
 
-	private volatile boolean releaseCalled;
+	private Flux<LLKeyScore> results;
+	private TotalHitsCount totalHitsCount;
 
-	private final Flux<LLKeyScore> results;
+	public LLSearchResultShard(Flux<LLKeyScore> results, TotalHitsCount totalHitsCount, Drop<LLSearchResultShard> drop) {
-	private final TotalHitsCount totalHitsCount;
+		super(drop);
-	private final Mono<Void> release;
-
-	public LLSearchResultShard(Flux<LLKeyScore> results, TotalHitsCount totalHitsCount, Mono<Void> release) {
 		this.results = results;
 		this.totalHitsCount = totalHitsCount;
-		this.release = Mono.fromRunnable(() -> {
-			if (releaseCalled) {
-				logger.warn(this.getClass().getName() + "::release has been called twice!");
-			}
-			releaseCalled = true;
-		}).then(release);
 	}
 
 	public Flux<LLKeyScore> results() {
+		if (!isOwned()) {
+			throw attachTrace(new IllegalStateException("LLSearchResultShard must be owned to be used"));
+		}
 		return results;
 	}
 
 	public TotalHitsCount totalHitsCount() {
-		return totalHitsCount;
+		if (!isOwned()) {
+			throw attachTrace(new IllegalStateException("LLSearchResultShard must be owned to be used"));
 		}
-
+		return totalHitsCount;
-	public Mono<Void> release() {
-		return release;
 	}
 
 	@Override
@@ -48,28 +43,33 @@ public final class LLSearchResultShard {
 		if (obj == null || obj.getClass() != this.getClass())
 			return false;
 		var that = (LLSearchResultShard) obj;
-		return Objects.equals(this.results, that.results) && Objects.equals(this.totalHitsCount, that.totalHitsCount)
+		return Objects.equals(this.results, that.results) && Objects.equals(this.totalHitsCount, that.totalHitsCount);
-				&& Objects.equals(this.release, that.release);
 	}
 
 	@Override
 	public int hashCode() {
-		return Objects.hash(results, totalHitsCount, release);
+		return Objects.hash(results, totalHitsCount);
 	}
 
 	@Override
 	public String toString() {
-		return "LLSearchResultShard[" + "results=" + results + ", " + "totalHitsCount=" + totalHitsCount + ", " + "release="
+		return "LLSearchResultShard[" + "results=" + results + ", " + "totalHitsCount=" + totalHitsCount + ']';
-				+ release + ']';
 	}
 
-	@SuppressWarnings("deprecation")
 	@Override
-	protected void finalize() throws Throwable {
+	protected RuntimeException createResourceClosedException() {
-		if (!releaseCalled) {
+		return new IllegalStateException("Closed");
-			logger.warn(this.getClass().getName() + "::release has not been called before class finalization!");
-		}
-		super.finalize();
 	}
 
+	@Override
+	protected Owned<LLSearchResultShard> prepareSend() {
+		var results = this.results;
+		var totalHitsCount = this.totalHitsCount;
+		return drop -> new LLSearchResultShard(results, totalHitsCount, drop);
+	}
+
+	protected void makeInaccessible() {
+		this.results = null;
+		this.totalHitsCount = null;
+	}
 }

src/main/java/it/cavallium/dbengine/database/LLUtils.java

@@ -1,10 +1,13 @@
 package it.cavallium.dbengine.database;
 
+import static org.apache.commons.lang3.ArrayUtils.EMPTY_BYTE_ARRAY;
+
 import com.google.common.primitives.Ints;
 import com.google.common.primitives.Longs;
 import io.net5.buffer.api.Buffer;
 import io.net5.buffer.api.BufferAllocator;
 import io.net5.buffer.api.CompositeBuffer;
+import io.net5.buffer.api.Resource;
 import io.net5.buffer.api.Send;
 import io.net5.util.IllegalReferenceCountException;
 import io.net5.util.internal.PlatformDependent;
@@ -15,6 +18,8 @@ import it.cavallium.dbengine.database.serialization.SerializationFunction;
 import it.cavallium.dbengine.lucene.RandomSortField;
 import java.nio.ByteBuffer;
 import java.nio.charset.Charset;
+import java.nio.charset.CharsetEncoder;
+import java.nio.charset.StandardCharsets;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.List;
@@ -24,6 +29,7 @@ import java.util.Objects;
 import java.util.Optional;
 import java.util.concurrent.Callable;
 import java.util.concurrent.atomic.AtomicLong;
+import java.util.function.Function;
 import java.util.function.ToIntFunction;
 import org.apache.lucene.document.Document;
 import org.apache.lucene.document.Field;
@@ -35,6 +41,7 @@ import org.apache.lucene.document.StringField;
 import org.apache.lucene.document.TextField;
 import org.apache.lucene.index.IndexableField;
 import org.apache.lucene.index.Term;
+import org.apache.lucene.search.ScoreDoc;
 import org.apache.lucene.search.ScoreMode;
 import org.apache.lucene.search.Sort;
 import org.apache.lucene.search.SortField;
@@ -48,6 +55,7 @@ import org.slf4j.Marker;
 import org.slf4j.MarkerFactory;
 import reactor.core.publisher.Flux;
 import reactor.core.publisher.Mono;
+import reactor.core.scheduler.Schedulers;
 import reactor.util.function.Tuple2;
 import reactor.util.function.Tuple3;
 
@@ -173,9 +181,9 @@ public class LLUtils {
 		return new it.cavallium.dbengine.database.LLKeyScore(hit.docId(), hit.score(), hit.key());
 	}
 
-	public static String toStringSafe(Buffer key) {
+	public static String toStringSafe(@Nullable Buffer key) {
 		try {
-			if (key.isAccessible()) {
+			if (key == null || key.isAccessible()) {
 				return toString(key);
 			} else {
 				return "(released)";
@@ -185,7 +193,35 @@ public class LLUtils {
 		}
 	}
 
-	public static String toString(Buffer key) {
+	public static String toStringSafe(@Nullable LLRange range) {
+		try {
+			if (range == null || range.isAccessible()) {
+				return toString(range);
+			} else {
+				return "(released)";
+			}
+		} catch (IllegalReferenceCountException ex) {
+			return "(released)";
+		}
+	}
+
+	public static String toString(@Nullable LLRange range) {
+		if (range == null) {
+			return "null";
+		} else if (range.isAll()) {
+			return "ξ";
+		} else if (range.hasMin() && range.hasMax()) {
+			return "[" + toStringSafe(range.getMinUnsafe()) + "," + toStringSafe(range.getMaxUnsafe()) + ")";
+		} else if (range.hasMin()) {
+			return "[" + toStringSafe(range.getMinUnsafe()) + ",*)";
+		} else if (range.hasMax()) {
+			return "[*," + toStringSafe(range.getMaxUnsafe()) + ")";
+		} else {
+			return "∅";
+		}
+	}
+
+	public static String toString(@Nullable Buffer key) {
 		if (key == null) {
 			return "null";
 		} else {
@@ -195,20 +231,37 @@ public class LLUtils {
 			if (iMax <= -1) {
 				return "[]";
 			} else {
-				StringBuilder b = new StringBuilder();
+				StringBuilder arraySB = new StringBuilder();
-				b.append('[');
+				StringBuilder asciiSB = new StringBuilder();
+				boolean isAscii = true;
+				arraySB.append('[');
 				int i = 0;
 
 				while (true) {
-					b.append(key.getByte(startIndex + i));
+					var byteVal = key.getUnsignedByte(startIndex + i);
+					arraySB.append(byteVal);
+					if (isAscii) {
+						if (byteVal >= 32 && byteVal < 127) {
+							asciiSB.append((char) byteVal);
+						} else if (byteVal == 0) {
+							asciiSB.append('␀');
+						} else {
+							isAscii = false;
+							asciiSB = null;
+						}
+					}
 					if (i == iLimit) {
-						b.append("…");
+						arraySB.append("…");
 					}
 					if (i == iMax || i == iLimit) {
-						return b.append(']').toString();
+						if (isAscii) {
+							return asciiSB.insert(0, "\"").append("\"").toString();
+						} else {
+							return arraySB.append(']').toString();
+						}
 					}
 
-					b.append(", ");
+					arraySB.append(", ");
 					++i;
 				}
 			}
@@ -257,7 +310,10 @@ public class LLUtils {
 		return true;
 	}
 
-	public static byte[] toArray(Buffer key) {
+	public static byte[] toArray(@Nullable Buffer key) {
+		if (key == null) {
+			return EMPTY_BYTE_ARRAY;
+		}
 		byte[] array = new byte[key.readableBytes()];
 		key.copyInto(key.readerOffset(), array, 0, key.readableBytes());
 		return array;
@@ -291,7 +347,7 @@ public class LLUtils {
 	 */
 	@SuppressWarnings("ConstantConditions")
 	@Nullable
-	public static Send<Buffer> readNullableDirectNioBuffer(BufferAllocator alloc, ToIntFunction<ByteBuffer> reader) {
+	public static Buffer readNullableDirectNioBuffer(BufferAllocator alloc, ToIntFunction<ByteBuffer> reader) {
 		ByteBuffer directBuffer;
 		Buffer buffer;
 		{
@@ -308,7 +364,7 @@ public class LLUtils {
 				if (size != RocksDB.NOT_FOUND) {
 					if (size == directBuffer.limit()) {
 						buffer.readerOffset(0).writerOffset(size);
-						return buffer.send();
+						return buffer;
 					} else {
 						assert size > directBuffer.limit();
 						assert directBuffer.limit() > 0;
@@ -318,7 +374,7 @@ public class LLUtils {
 							PlatformDependent.freeDirectBuffer(directBuffer);
 							directBuffer = null;
 						}
-						directBuffer = LLUtils.obtainDirect(buffer);
+						directBuffer = LLUtils.obtainDirect(buffer, true);
 						buffer.ensureWritable(size);
 					}
 				}
@@ -333,7 +389,131 @@ public class LLUtils {
 				PlatformDependent.freeDirectBuffer(directBuffer);
 				directBuffer = null;
 			}
-			buffer.close();
+		}
+	}
+
+	public static void ensureBlocking() {
+		if (Schedulers.isInNonBlockingThread()) {
+			throw new UnsupportedOperationException("Called collect in a nonblocking thread");
+		}
+	}
+
+	/**
+	 * cleanup resource
+	 * @param cleanupOnSuccess if true the resource will be cleaned up if the function is successful
+	 */
+	public static <U, T extends Resource<T>> Mono<U> usingSend(Mono<Send<T>> resourceSupplier,
+			Function<Send<T>, Mono<U>> resourceClosure,
+			boolean cleanupOnSuccess) {
+		return Mono.usingWhen(resourceSupplier, resourceClosure, r -> {
+			if (cleanupOnSuccess) {
+				return Mono.fromRunnable(() -> r.close());
+			} else {
+				return Mono.empty();
+			}
+		}, (r, ex) -> Mono.fromRunnable(() -> r.close()), r -> Mono.fromRunnable(() -> r.close()))
+				.doOnDiscard(Send.class, send -> send.close());
+	}
+
+	/**
+	 * cleanup resource
+	 * @param cleanupOnSuccess if true the resource will be cleaned up if the function is successful
+	 */
+	public static <U, T extends Resource<T>, V extends T> Mono<U> usingResource(Mono<V> resourceSupplier,
+			Function<V, Mono<U>> resourceClosure,
+			boolean cleanupOnSuccess) {
+		return Mono.usingWhen(resourceSupplier, resourceClosure, r -> {
+					if (cleanupOnSuccess) {
+						return Mono.fromRunnable(() -> r.close());
+					} else {
+						return Mono.empty();
+					}
+				}, (r, ex) -> Mono.fromRunnable(() -> r.close()), r -> Mono.fromRunnable(() -> r.close()))
+				.doOnDiscard(Resource.class, resource -> resource.close())
+				.doOnDiscard(Send.class, send -> send.close());
+	}
+
+	/**
+	 * cleanup resource
+	 * @param cleanupOnSuccess if true the resource will be cleaned up if the function is successful
+	 */
+	public static <U, T extends Resource<T>, V extends T> Flux<U> usingEachResource(Flux<V> resourceSupplier,
+			Function<V, Mono<U>> resourceClosure,
+			boolean cleanupOnSuccess) {
+		return resourceSupplier
+				.concatMap(resource -> Mono.usingWhen(Mono.just(resource), resourceClosure, r -> {
+					if (cleanupOnSuccess) {
+						return Mono.fromRunnable(() -> r.close());
+					} else {
+						return Mono.empty();
+					}
+				}, (r, ex) -> Mono.fromRunnable(() -> r.close()), r -> Mono.fromRunnable(() -> r.close())))
+				.doOnDiscard(Resource.class, resource -> resource.close())
+				.doOnDiscard(Send.class, send -> send.close());
+	}
+
+	/**
+	 * cleanup resource
+	 * @param cleanupOnSuccess if true the resource will be cleaned up if the function is successful
+	 */
+	public static <U, T extends Resource<T>> Mono<U> usingSendResource(Mono<Send<T>> resourceSupplier,
+			Function<T, Mono<U>> resourceClosure,
+			boolean cleanupOnSuccess) {
+		return Mono.usingWhen(resourceSupplier.map(Send::receive), resourceClosure, r -> {
+					if (cleanupOnSuccess) {
+						return Mono.fromRunnable(() -> r.close());
+					} else {
+						return Mono.empty();
+					}
+				}, (r, ex) -> Mono.fromRunnable(() -> r.close()), r -> Mono.fromRunnable(() -> r.close()))
+				.doOnDiscard(Resource.class, resource -> resource.close())
+				.doOnDiscard(Send.class, send -> send.close());
+	}
+
+	/**
+	 * cleanup resource
+	 * @param cleanupOnSuccess if true the resource will be cleaned up if the function is successful
+	 */
+	public static <U, T extends Resource<T>> Flux<U> usingSendResources(Mono<Send<T>> resourceSupplier,
+			Function<T, Flux<U>> resourceClosure,
+			boolean cleanupOnSuccess) {
+		return Flux.usingWhen(resourceSupplier.map(Send::receive), resourceClosure, r -> {
+					if (cleanupOnSuccess) {
+						return Mono.fromRunnable(() -> r.close());
+					} else {
+						return Mono.empty();
+					}
+				}, (r, ex) -> Mono.fromRunnable(() -> r.close()), r -> Mono.fromRunnable(() -> r.close()))
+				.doOnDiscard(Resource.class, resource -> resource.close())
+				.doOnDiscard(Send.class, send -> send.close());
+	}
+
+	public static boolean isSet(ScoreDoc[] scoreDocs) {
+		for (ScoreDoc scoreDoc : scoreDocs) {
+			if (scoreDoc == null) {
+				return false;
+			}
+		}
+		return true;
+	}
+
+	public static Send<Buffer> empty(BufferAllocator allocator) {
+		try {
+			return allocator.allocate(0).send();
+		} catch (Exception ex) {
+			try (var empty = CompositeBuffer.compose(allocator)) {
+				assert empty.readableBytes() == 0;
+				assert empty.capacity() == 0;
+				return empty.send();
+			}
+		}
+	}
+
+	public static Send<Buffer> copy(BufferAllocator allocator, Buffer buf) {
+		if (CompositeBuffer.isComposite(buf) && buf.capacity() == 0) {
+			return empty(allocator);
+		} else {
+			return buf.copy().send();
 		}
 	}
 
@@ -342,29 +522,33 @@ public class LLUtils {
 	@NotNull
 	public static DirectBuffer newDirect(BufferAllocator allocator, int size) {
 		try (var buf = allocator.allocate(size)) {
-			var direct = obtainDirect(buf);
+			var direct = obtainDirect(buf, true);
 			return new DirectBuffer(buf.send(), direct);
 		}
 	}
 
 	@NotNull
-	public static DirectBuffer convertToDirect(BufferAllocator allocator, Send<Buffer> content) {
+	public static DirectBuffer convertToReadableDirect(BufferAllocator allocator, Send<Buffer> content) {
 		try (var buf = content.receive()) {
-			if (buf.countComponents() != 0) {
+			DirectBuffer result;
-				var direct = obtainDirect(buf);
+			if (buf.countComponents() == 1) {
-				return new DirectBuffer(buf.send(), direct);
+				var direct = obtainDirect(buf, false);
+				result = new DirectBuffer(buf.send(), direct);
 			} else {
 				var direct = newDirect(allocator, buf.readableBytes());
 				try (var buf2 = direct.buffer().receive()) {
 					buf.copyInto(buf.readerOffset(), buf2, buf2.writerOffset(), buf.readableBytes());
-					return new DirectBuffer(buf2.send(), direct.byteBuffer());
+					buf2.writerOffset(buf2.writerOffset() + buf.readableBytes());
+					assert buf2.readableBytes() == buf.readableBytes();
+					result = new DirectBuffer(buf2.send(), direct.byteBuffer());
 				}
 			}
+			return result;
 		}
 	}
 
 	@NotNull
-	public static ByteBuffer obtainDirect(Buffer buffer) {
+	public static ByteBuffer obtainDirect(Buffer buffer, boolean writable) {
 		if (!PlatformDependent.hasUnsafe()) {
 			throw new UnsupportedOperationException("Please enable unsafe support or disable netty direct buffers",
 					PlatformDependent.getUnsafeUnavailabilityCause()
@@ -372,16 +556,34 @@ public class LLUtils {
 		}
 		if (!MemorySegmentUtils.isSupported()) {
 			throw new UnsupportedOperationException("Foreign Memory Access API support is disabled."
-					+ " Please set \"--enable-preview --add-modules jdk.incubator.foreign -Dforeign.restricted=permit\"");
+					+ " Please set \"" + MemorySegmentUtils.getSuggestedArgs() + "\"",
+					MemorySegmentUtils.getUnsupportedCause()
+			);
 		}
 		assert buffer.isAccessible();
+		buffer.compact();
+		assert buffer.readerOffset() == 0;
 		AtomicLong nativeAddress = new AtomicLong(0);
-		if (buffer.countComponents() == 1 && buffer.countReadableComponents() == 1) {
+		if (buffer.countComponents() == 1) {
+			if (writable) {
+				if (buffer.countWritableComponents() == 1) {
+					buffer.forEachWritable(0, (i, c) -> {
+						assert c.writableNativeAddress() != 0;
+						nativeAddress.setPlain(c.writableNativeAddress());
+						return false;
+					});
+				}
+			} else {
+				var readableComponents = buffer.countReadableComponents();
+				if (readableComponents == 1) {
 					buffer.forEachReadable(0, (i, c) -> {
+						assert c.readableNativeAddress() != 0;
 						nativeAddress.setPlain(c.readableNativeAddress());
 						return false;
 					});
 				}
+			}
+		}
 		if (nativeAddress.getPlain() == 0) {
 			if (buffer.capacity() == 0) {
 				return EMPTY_BYTE_BUFFER;
@@ -391,7 +593,7 @@ public class LLUtils {
 			}
 			throw new IllegalStateException("Buffer is not direct");
 		}
-		return MemorySegmentUtils.directBuffer(nativeAddress.getPlain(), buffer.capacity());
+		return MemorySegmentUtils.directBuffer(nativeAddress.getPlain(), writable ? buffer.capacity() : buffer.writerOffset());
 	}
 
 	public static Buffer fromByteArray(BufferAllocator alloc, byte[] array) {
@@ -401,83 +603,57 @@ public class LLUtils {
 	}
 
 	@NotNull
-	public static Send<Buffer> readDirectNioBuffer(BufferAllocator alloc, ToIntFunction<ByteBuffer> reader) {
+	public static Buffer readDirectNioBuffer(BufferAllocator alloc, ToIntFunction<ByteBuffer> reader) {
-		var nullableSend = readNullableDirectNioBuffer(alloc, reader);
+		var nullable = readNullableDirectNioBuffer(alloc, reader);
-		try (var buffer = nullableSend != null ? nullableSend.receive() : null) {
+		if (nullable == null) {
-			if (buffer == null) {
 			throw new IllegalStateException("A non-nullable buffer read operation tried to return a \"not found\" element");
 		}
-			return buffer.send();
+		return nullable;
-		}
 	}
 
-	public static Send<Buffer> compositeBuffer(BufferAllocator alloc, Send<Buffer> buffer) {
+	public static Buffer compositeBuffer(BufferAllocator alloc, Send<Buffer> buffer) {
-		try (var composite = buffer.receive()) {
+		return buffer.receive();
-			return composite.send();
-		}
 	}
 
-	public static Send<Buffer> compositeBuffer(BufferAllocator alloc, Send<Buffer> buffer1, Send<Buffer> buffer2) {
+	@NotNull
-		try (var buf1 = buffer1.receive()) {
+	public static Buffer compositeBuffer(BufferAllocator alloc,
-			try (var buf2 = buffer2.receive()) {
+			@NotNull Send<Buffer> buffer1,
-				try (var composite = CompositeBuffer.compose(alloc, buf1.split().send(), buf2.split().send())) {
+			@NotNull Send<Buffer> buffer2) {
-					return composite.send();
+		var b1 = buffer1.receive();
-				}
+		try (var b2 = buffer2.receive()) {
+			if (b1.writerOffset() < b1.capacity() || b2.writerOffset() < b2.capacity()) {
+				b1.ensureWritable(b2.readableBytes(), b2.readableBytes(), true);
+				b2.copyInto(b2.readerOffset(), b1, b1.writerOffset(), b2.readableBytes());
+				b1.writerOffset(b1.writerOffset() + b2.readableBytes());
+				return b1;
+			} else {
+				return CompositeBuffer.compose(alloc, b1.send(), b2.send());
 			}
 		}
 	}
 
-	public static Send<Buffer> compositeBuffer(BufferAllocator alloc,
+	@NotNull
-			Send<Buffer> buffer1,
+	public static Buffer compositeBuffer(BufferAllocator alloc,
-			Send<Buffer> buffer2,
+			@NotNull Send<Buffer> buffer1,
-			Send<Buffer> buffer3) {
+			@NotNull Send<Buffer> buffer2,
-		try (var buf1 = buffer1.receive()) {
+			@NotNull Send<Buffer> buffer3) {
-			try (var buf2 = buffer2.receive()) {
+		var b1 = buffer1.receive();
-				try (var buf3 = buffer3.receive()) {
+		try (var b2 = buffer2.receive()) {
-					try (var composite = CompositeBuffer.compose(alloc,
+			try (var b3 = buffer3.receive()) {
-							buf1.split().send(),
+				if (b1.writerOffset() < b1.capacity()
-							buf2.split().send(),
+						|| b2.writerOffset() < b2.capacity()
-							buf3.split().send()
+						|| b3.writerOffset() < b3.capacity()) {
-					)) {
+					b1.ensureWritable(b2.readableBytes(), b2.readableBytes(), true);
-						return composite.send();
+					b2.copyInto(b2.readerOffset(), b1, b1.writerOffset(), b2.readableBytes());
-					}
+					b1.writerOffset(b1.writerOffset() + b2.readableBytes());
-				}
-			}
-		}
-	}
 
-	@SafeVarargs
+					b1.ensureWritable(b3.readableBytes(), b3.readableBytes(), true);
-	public static Send<Buffer> compositeBuffer(BufferAllocator alloc, Send<Buffer>... buffers) {
+					b3.copyInto(b3.readerOffset(), b1, b1.writerOffset(), b3.readableBytes());
-		try {
+					b1.writerOffset(b1.writerOffset() + b3.readableBytes());
-			return switch (buffers.length) {
+					return b1;
-				case 0 -> alloc.allocate(0).send();
+				} else {
-				case 1 -> compositeBuffer(alloc, buffers[0]);
+					return CompositeBuffer.compose(alloc, b1.send(), b2.send(), b3.send());
-				case 2 -> compositeBuffer(alloc, buffers[0], buffers[1]);
-				case 3 -> compositeBuffer(alloc, buffers[0], buffers[1], buffers[2]);
-				default -> {
-					Buffer[] bufs = new Buffer[buffers.length];
-					for (int i = 0; i < buffers.length; i++) {
-						bufs[i] = buffers[i].receive();
 				}
-					try {
-						//noinspection unchecked
-						Send<Buffer>[] sentBufs = new Send[buffers.length];
-						for (int i = 0; i < buffers.length; i++) {
-							sentBufs[i] = bufs[i].split().send();
-						}
-						try (var composite = CompositeBuffer.compose(alloc, sentBufs)) {
-							yield composite.send();
-						}
-					} finally {
-						for (Buffer buf : bufs) {
-							buf.close();
-						}
-					}
-				}
-			};
-		} finally {
-			for (Send<Buffer> buffer : buffers) {
-				buffer.close();
 			}
 		}
 	}
@@ -807,7 +983,9 @@ public class LLUtils {
 	}
 
 	private static void discardStage(DatabaseStage<?> stage) {
-		stage.release();
+		if (stage != null && stage.isAccessible()) {
+			stage.close();
+		}
 	}
 
 	public static boolean isDirect(Buffer key) {

src/main/java/it/cavallium/dbengine/database/LiveResourceSupport.java

@@ -0,0 +1,32 @@
+package it.cavallium.dbengine.database;
+
+import io.net5.buffer.api.Drop;
+import io.net5.buffer.api.Owned;
+import io.net5.buffer.api.Resource;
+import io.net5.buffer.api.internal.LifecycleTracer;
+import io.net5.buffer.api.internal.ResourceSupport;
+import org.warp.commonutils.log.Logger;
+import org.warp.commonutils.log.LoggerFactory;
+
+public abstract class LiveResourceSupport<I extends Resource<I>, T extends LiveResourceSupport<I, T>> extends ResourceSupport<I, T> {
+
+	private static final Logger logger = LoggerFactory.getLogger(LiveResourceSupport.class);
+
+	protected LiveResourceSupport(Drop<T> drop) {
+		super(drop);
+	}
+
+	@Override
+	protected void finalize() throws Throwable {
+		if (this.isAccessible()) {
+			var ise = new IllegalStateException("Resource not released");
+			ise.setStackTrace(new StackTraceElement[0]);
+			logger.error("Resource not released: {}", this, attachTrace(ise));
+			try {
+				this.close();
+			} catch (Throwable ignored) {
+			}
+		}
+		super.finalize();
+	}
+}

src/main/java/it/cavallium/dbengine/database/RepeatedElementList.java

@@ -46,7 +46,7 @@ public class RepeatedElementList<T> implements List<T> {
 
 	@NotNull
 	@Override
-	public Object[] toArray() {
+	public Object @NotNull [] toArray() {
 		var arr = new Object[size];
 		Arrays.fill(arr, element);
 		return arr;
@@ -54,7 +54,7 @@ public class RepeatedElementList<T> implements List<T> {
 
 	@NotNull
 	@Override
-	public <T1> T1[] toArray(@NotNull T1[] a) {
+	public <T1> T1 @NotNull [] toArray(@NotNull T1 @NotNull [] a) {
 		var arr = Arrays.copyOf(a, size);
 		Arrays.fill(arr, element);
 		return arr;
@@ -152,8 +152,9 @@ public class RepeatedElementList<T> implements List<T> {
 	@NotNull
 	@Override
 	public ListIterator<T> listIterator(int index) {
-		return new ListIterator<T>() {
+		return new ListIterator<>() {
 			int position = index - 1;
+
 			@Override
 			public boolean hasNext() {
 				return position + 1 < size;

src/main/java/it/cavallium/dbengine/database/collections/DatabaseEmpty.java

@@ -2,11 +2,14 @@ package it.cavallium.dbengine.database.collections;
 
 import io.net5.buffer.api.Buffer;
 import io.net5.buffer.api.BufferAllocator;
+import io.net5.buffer.api.Drop;
 import io.net5.buffer.api.Send;
 import it.cavallium.dbengine.database.LLDictionary;
+import it.cavallium.dbengine.database.LLUtils;
 import it.cavallium.dbengine.database.serialization.Serializer;
 import it.cavallium.dbengine.database.serialization.Serializer.DeserializationResult;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
 public class DatabaseEmpty {
 
@@ -17,7 +20,7 @@ public class DatabaseEmpty {
 	public static Serializer<Nothing> nothingSerializer(BufferAllocator bufferAllocator) {
 		return new Serializer<>() {
 			@Override
-			public @NotNull DeserializationResult<Nothing> deserialize(@NotNull Send<Buffer> serialized) {
+			public @NotNull DeserializationResult<Nothing> deserialize(@Nullable Send<Buffer> serialized) {
 				try (serialized) {
 					return NOTHING_RESULT;
 				}
@@ -25,7 +28,7 @@ public class DatabaseEmpty {
 
 			@Override
 			public @NotNull Send<Buffer> serialize(@NotNull Nothing deserialized) {
-				return bufferAllocator.allocate(0).send();
+				return LLUtils.empty(bufferAllocator);
 			}
 		};
 	}
@@ -33,8 +36,10 @@ public class DatabaseEmpty {
 	private DatabaseEmpty() {
 	}
 
-	public static DatabaseStageEntry<Nothing> create(LLDictionary dictionary, Send<Buffer> key) {
+	public static DatabaseStageEntry<Nothing> create(LLDictionary dictionary,
-		return new DatabaseSingle<>(dictionary, key, nothingSerializer(dictionary.getAllocator()));
+			Send<Buffer> key,
+			Drop<DatabaseSingle<Nothing>> drop) {
+		return new DatabaseSingle<>(dictionary, key, nothingSerializer(dictionary.getAllocator()), drop);
 	}
 
 	public static final class Nothing {

src/main/java/it/cavallium/dbengine/database/collections/DatabaseMapDictionary.java

@@ -1,6 +1,7 @@
 package it.cavallium.dbengine.database.collections;
 
 import io.net5.buffer.api.Buffer;
+import io.net5.buffer.api.Drop;
 import io.net5.buffer.api.Send;
 import io.net5.buffer.api.internal.ResourceSupport;
 import it.cavallium.dbengine.client.CompositeSnapshot;
@@ -24,6 +25,7 @@ import java.util.Map;
 import java.util.Map.Entry;
 import java.util.Objects;
 import java.util.Optional;
+import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 import reactor.core.publisher.Flux;
 import reactor.core.publisher.Mono;
@@ -39,31 +41,46 @@ public class DatabaseMapDictionary<T, U> extends DatabaseMapDictionaryDeep<T, U,
 	private final Serializer<U> valueSerializer;
 
 	protected DatabaseMapDictionary(LLDictionary dictionary,
-			Send<Buffer> prefixKey,
+			@NotNull Send<Buffer> prefixKey,
 			SerializerFixedBinaryLength<T> keySuffixSerializer,
-			Serializer<U> valueSerializer) {
+			Serializer<U> valueSerializer,
+			Drop<DatabaseMapDictionaryDeep<T, U, DatabaseStageEntry<U>>> drop) {
 		// Do not retain or release or use the prefixKey here
-		super(dictionary, prefixKey, keySuffixSerializer, new SubStageGetterSingle<>(valueSerializer), 0);
+		super(dictionary, prefixKey, keySuffixSerializer, new SubStageGetterSingle<>(valueSerializer), 0, drop);
 		this.valueSerializer = valueSerializer;
 	}
 
 	public static <T, U> DatabaseMapDictionary<T, U> simple(LLDictionary dictionary,
 			SerializerFixedBinaryLength<T> keySerializer,
-			Serializer<U> valueSerializer) {
+			Serializer<U> valueSerializer,
-		return new DatabaseMapDictionary<>(dictionary, dictionary.getAllocator().allocate(0).send(), keySerializer, valueSerializer);
+			Drop<DatabaseMapDictionaryDeep<T, U, DatabaseStageEntry<U>>> drop) {
+		return new DatabaseMapDictionary<>(dictionary, LLUtils.empty(dictionary.getAllocator()), keySerializer,
+				valueSerializer, drop);
 	}
 
 	public static <T, U> DatabaseMapDictionary<T, U> tail(LLDictionary dictionary,
 			Send<Buffer> prefixKey,
 			SerializerFixedBinaryLength<T> keySuffixSerializer,
-			Serializer<U> valueSerializer) {
+			Serializer<U> valueSerializer,
-		return new DatabaseMapDictionary<>(dictionary, prefixKey, keySuffixSerializer, valueSerializer);
+			Drop<DatabaseMapDictionaryDeep<T, U, DatabaseStageEntry<U>>> drop) {
+		return new DatabaseMapDictionary<>(dictionary, prefixKey, keySuffixSerializer, valueSerializer, drop);
 	}
 
 	private Send<Buffer> toKey(Send<Buffer> suffixKeyToSend) {
 		try (var suffixKey = suffixKeyToSend.receive()) {
 			assert suffixKeyConsistency(suffixKey.readableBytes());
-			return LLUtils.compositeBuffer(dictionary.getAllocator(), keyPrefix.copy().send(), suffixKey.send());
+			if (keyPrefix.readableBytes() > 0) {
+				try (var result = LLUtils.compositeBuffer(dictionary.getAllocator(),
+						LLUtils.copy(dictionary.getAllocator(), keyPrefix),
+						suffixKey.send()
+				)) {
+					assert result.readableBytes() == keyPrefixLength + keySuffixLength + keyExtLength;
+					return result.send();
+				}
+			} else {
+				assert suffixKey.readableBytes() == keyPrefixLength + keySuffixLength + keyExtLength;
+				return suffixKey.send();
+			}
 		}
 	}
 
@@ -81,7 +98,12 @@ public class DatabaseMapDictionary<T, U> extends DatabaseMapDictionaryDeep<T, U,
 				.getRange(resolveSnapshot(snapshot), rangeMono, existsAlmostCertainly)
 				.<Entry<T, U>>handle((entrySend, sink) -> {
 					try (var entry = entrySend.receive()) {
-						var key = deserializeSuffix(stripPrefix(entry.getKey()));
+						T key;
+						try (var serializedKey = entry.getKey().receive()) {
+							removePrefix(serializedKey);
+							suffixKeyConsistency(serializedKey.readableBytes());
+							key = deserializeSuffix(serializedKey.send());
+						}
 						var value = valueSerializer.deserialize(entry.getValue()).deserializedData();
 						sink.next(Map.entry(key, value));
 					} catch (SerializationException ex) {
@@ -130,20 +152,23 @@ public class DatabaseMapDictionary<T, U> extends DatabaseMapDictionaryDeep<T, U,
 	@Override
 	public Mono<DatabaseStageEntry<U>> at(@Nullable CompositeSnapshot snapshot, T keySuffix) {
 		return Mono.fromCallable(() ->
-				new DatabaseSingle<>(dictionary, toKey(serializeSuffix(keySuffix)), valueSerializer));
+				new DatabaseSingle<>(dictionary, toKey(serializeSuffix(keySuffix)), valueSerializer, d -> {}));
 	}
 
 	@Override
 	public Mono<U> getValue(@Nullable CompositeSnapshot snapshot, T keySuffix, boolean existsAlmostCertainly) {
 		return dictionary
-				.get(resolveSnapshot(snapshot), Mono.fromCallable(() -> toKey(serializeSuffix(keySuffix))), existsAlmostCertainly)
+				.get(resolveSnapshot(snapshot),
+						Mono.fromCallable(() -> toKey(serializeSuffix(keySuffix))),
+						existsAlmostCertainly
+				)
 				.handle((value, sink) -> deserializeValue(value, sink));
 	}
 
 	@Override
 	public Mono<Void> putValue(T keySuffix, U value) {
-		var keyMono = Mono.fromCallable(() -> toKey(serializeSuffix(keySuffix)));
+		var keyMono = Mono.fromCallable(() -> toKey(serializeSuffix(keySuffix))).single();
-		var valueMono = Mono.fromCallable(() -> valueSerializer.serialize(value));
+		var valueMono = Mono.fromCallable(() -> valueSerializer.serialize(value)).single();
 		return dictionary
 				.put(keyMono, valueMono, LLDictionaryResultType.VOID)
 				.doOnNext(Send::close)
@@ -297,9 +322,10 @@ public class DatabaseMapDictionary<T, U> extends DatabaseMapDictionaryDeep<T, U,
 	}
 
 	private Send<LLEntry> serializeEntry(T key, U value) throws SerializationException {
-		try (var serializedKey = toKey(serializeSuffix(key)).receive()) {
+		try (var serializedKey = toKey(serializeSuffix(key))) {
-			try (var serializedValue = valueSerializer.serialize(value).receive()) {
+			var serializedValueToReceive = valueSerializer.serialize(value);
-				return LLEntry.of(serializedKey.send(), serializedValue.send()).send();
+			try (var serializedValue = serializedValueToReceive.receive()) {
+				return LLEntry.of(serializedKey, serializedValue.send()).send();
 			}
 		}
 	}
@@ -368,16 +394,15 @@ public class DatabaseMapDictionary<T, U> extends DatabaseMapDictionaryDeep<T, U,
 	public Flux<Entry<T, DatabaseStageEntry<U>>> getAllStages(@Nullable CompositeSnapshot snapshot) {
 		return dictionary
 				.getRangeKeys(resolveSnapshot(snapshot), rangeMono)
-				.handle((key, sink) -> {
+				.handle((keyBufToReceive, sink) -> {
-					try (key) {
+					try (var keyBuf = keyBufToReceive.receive()) {
-						try (var keySuffixWithExt = stripPrefix(key).receive()) {
+						assert keyBuf.readableBytes() == keyPrefixLength + keySuffixLength + keyExtLength;
-							sink.next(Map.entry(deserializeSuffix(keySuffixWithExt.copy().send()),
+						// Remove prefix. Keep only the suffix and the ext
-									new DatabaseSingle<>(dictionary,
+						removePrefix(keyBuf);
-											toKey(keySuffixWithExt.send()),
+						suffixKeyConsistency(keyBuf.readableBytes());
-											valueSerializer
+						sink.next(Map.entry(deserializeSuffix(keyBuf.copy().send()),
-									)
+								new DatabaseSingle<>(dictionary, toKey(keyBuf.send()), valueSerializer, d -> {})
 						));
-						}
 					} catch (SerializationException ex) {
 						sink.error(ex);
 					}
@@ -390,8 +415,14 @@ public class DatabaseMapDictionary<T, U> extends DatabaseMapDictionaryDeep<T, U,
 				.getRange(resolveSnapshot(snapshot), rangeMono)
 				.<Entry<T, U>>handle((serializedEntryToReceive, sink) -> {
 					try (var serializedEntry = serializedEntryToReceive.receive()) {
-						sink.next(Map.entry(deserializeSuffix(stripPrefix(serializedEntry.getKey())),
+						try (var keyBuf = serializedEntry.getKey().receive()) {
+							assert keyBuf.readableBytes() == keyPrefixLength + keySuffixLength + keyExtLength;
+							// Remove prefix. Keep only the suffix and the ext
+							removePrefix(keyBuf);
+							suffixKeyConsistency(keyBuf.readableBytes());
+							sink.next(Map.entry(deserializeSuffix(keyBuf.send()),
 									valueSerializer.deserialize(serializedEntry.getValue()).deserializedData()));
+						}
 					} catch (SerializationException e) {
 						sink.error(e);
 					}

src/main/java/it/cavallium/dbengine/database/collections/DatabaseMapDictionaryDeep.java

@@ -2,8 +2,11 @@ package it.cavallium.dbengine.database.collections;
 
 import io.net5.buffer.api.Buffer;
 import io.net5.buffer.api.BufferAllocator;
+import io.net5.buffer.api.Drop;
+import io.net5.buffer.api.Owned;
 import io.net5.buffer.api.Resource;
 import io.net5.buffer.api.Send;
+import io.net5.buffer.api.internal.ResourceSupport;
 import io.net5.util.IllegalReferenceCountException;
 import it.cavallium.dbengine.client.BadBlock;
 import it.cavallium.dbengine.client.CompositeSnapshot;
@@ -12,152 +15,116 @@ import it.cavallium.dbengine.database.LLDictionaryResultType;
 import it.cavallium.dbengine.database.LLRange;
 import it.cavallium.dbengine.database.LLSnapshot;
 import it.cavallium.dbengine.database.LLUtils;
+import it.cavallium.dbengine.database.LiveResourceSupport;
 import it.cavallium.dbengine.database.UpdateMode;
 import it.cavallium.dbengine.database.serialization.SerializationException;
 import it.cavallium.dbengine.database.serialization.SerializerFixedBinaryLength;
 import java.util.Map;
 import java.util.Map.Entry;
+import java.util.Objects;
+import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 import reactor.core.publisher.Flux;
 import reactor.core.publisher.Mono;
 
 // todo: implement optimized methods (which?)
-public class DatabaseMapDictionaryDeep<T, U, US extends DatabaseStage<U>> implements DatabaseStageMap<T, U, US> {
+public class DatabaseMapDictionaryDeep<T, U, US extends DatabaseStage<U>> extends
+		LiveResourceSupport<DatabaseStage<Map<T, U>>, DatabaseMapDictionaryDeep<T, U, US>>
+		implements DatabaseStageMap<T, U, US> {
 
 	protected final LLDictionary dictionary;
 	private final BufferAllocator alloc;
 	protected final SubStageGetter<U, US> subStageGetter;
 	protected final SerializerFixedBinaryLength<T> keySuffixSerializer;
-	protected final Buffer keyPrefix;
 	protected final int keyPrefixLength;
 	protected final int keySuffixLength;
 	protected final int keyExtLength;
-	protected final LLRange range;
 	protected final Mono<Send<LLRange>> rangeMono;
-	private volatile boolean released;
 
-	private static Send<Buffer> incrementPrefix(BufferAllocator alloc, Send<Buffer> originalKeySend, int prefixLength) {
+	protected LLRange range;
-		try (var originalKey = originalKeySend.receive()) {
+	protected Buffer keyPrefix;
-			assert originalKey.readableBytes() >= prefixLength;
+
-			var originalKeyLength = originalKey.readableBytes();
+	private static void incrementPrefix(Buffer prefix, int prefixLength) {
-			try (Buffer copiedBuf = alloc.allocate(originalKey.readableBytes())) {
+		assert prefix.readableBytes() >= prefixLength;
+		assert prefix.readerOffset() == 0;
+		final var originalKeyLength = prefix.readableBytes();
 		boolean overflowed = true;
 		final int ff = 0xFF;
 		int writtenBytes = 0;
-				copiedBuf.writerOffset(prefixLength);
 		for (int i = prefixLength - 1; i >= 0; i--) {
-					int iByte = originalKey.getUnsignedByte(i);
+			int iByte = prefix.getUnsignedByte(i);
 			if (iByte != ff) {
-						copiedBuf.setUnsignedByte(i, iByte + 1);
+				prefix.setUnsignedByte(i, iByte + 1);
 				writtenBytes++;
 				overflowed = false;
 				break;
 			} else {
-						copiedBuf.setUnsignedByte(i, 0x00);
+				prefix.setUnsignedByte(i, 0x00);
 				writtenBytes++;
-						overflowed = true;
 			}
 		}
 		assert prefixLength - writtenBytes >= 0;
-				if (prefixLength - writtenBytes > 0) {
-					originalKey.copyInto(0, copiedBuf, 0, (prefixLength - writtenBytes));
-				}
-
-				copiedBuf.writerOffset(originalKeyLength);
-
-				if (originalKeyLength - prefixLength > 0) {
-					originalKey.copyInto(prefixLength, copiedBuf, prefixLength, originalKeyLength - prefixLength);
-				}
 
 		if (overflowed) {
-					copiedBuf.ensureWritable(originalKeyLength + 1);
+			assert prefix.writerOffset() == originalKeyLength;
-					copiedBuf.writerOffset(originalKeyLength + 1);
+			prefix.ensureWritable(1, 1, true);
+			prefix.writerOffset(originalKeyLength + 1);
 			for (int i = 0; i < originalKeyLength; i++) {
-						copiedBuf.setUnsignedByte(i, 0xFF);
+				prefix.setUnsignedByte(i, 0xFF);
-					}
-					copiedBuf.setUnsignedByte(originalKeyLength, (byte) 0x00);
-				}
-				return copiedBuf.send();
 			}
+			prefix.setUnsignedByte(originalKeyLength, (byte) 0x00);
 		}
 	}
 
-	static Send<Buffer> firstRangeKey(BufferAllocator alloc,
+	static Buffer firstRangeKey(BufferAllocator alloc, Send<Buffer> prefixKey, int prefixLength, int suffixLength,
-			Send<Buffer> prefixKey,
-			int prefixLength,
-			int suffixLength,
 			int extLength) {
 		return zeroFillKeySuffixAndExt(alloc, prefixKey, prefixLength, suffixLength, extLength);
 	}
 
-	static Send<Buffer> nextRangeKey(BufferAllocator alloc,
+	static Buffer nextRangeKey(BufferAllocator alloc, Send<Buffer> prefixKey, int prefixLength, int suffixLength,
-			Send<Buffer> prefixKey,
-			int prefixLength,
-			int suffixLength,
 			int extLength) {
 		try (prefixKey) {
-			try (Send<Buffer> nonIncremented = zeroFillKeySuffixAndExt(alloc, prefixKey, prefixLength, suffixLength,
+			Buffer nonIncremented = zeroFillKeySuffixAndExt(alloc, prefixKey, prefixLength, suffixLength, extLength);
-					extLength)) {
+			incrementPrefix(nonIncremented, prefixLength);
-				return incrementPrefix(alloc, nonIncremented, prefixLength);
+			return nonIncremented;
-			}
 		}
 	}
 
-	protected static Send<Buffer> zeroFillKeySuffixAndExt(BufferAllocator alloc,
+	protected static Buffer zeroFillKeySuffixAndExt(BufferAllocator alloc, @NotNull Send<Buffer> prefixKeySend,
-			Send<Buffer> prefixKeySend,
+			int prefixLength, int suffixLength, int extLength) {
-			int prefixLength,
+		var result = prefixKeySend.receive();
-			int suffixLength,
+		if (result == null) {
-			int extLength) {
+			assert prefixLength == 0;
-		try (var prefixKey = prefixKeySend.receive()) {
+			var buf = alloc.allocate(prefixLength + suffixLength + extLength);
-			assert prefixKey.readableBytes() == prefixLength;
+			buf.writerOffset(prefixLength + suffixLength + extLength);
+			buf.fill((byte) 0);
+			return buf;
+		} else {
+			assert result.readableBytes() == prefixLength;
 			assert suffixLength > 0;
 			assert extLength >= 0;
-			try (Buffer zeroSuffixAndExt = alloc.allocate(suffixLength + extLength)) {
+			result.ensureWritable(suffixLength + extLength, suffixLength + extLength, true);
 			for (int i = 0; i < suffixLength + extLength; i++) {
-					zeroSuffixAndExt.writeByte((byte) 0x0);
+				result.writeByte((byte) 0x0);
-				}
-				try (Buffer result = LLUtils.compositeBuffer(alloc, prefixKey.send(), zeroSuffixAndExt.send()).receive()) {
-					return result.send();
-				}
 			}
+			return result;
 		}
 	}
 
-	static Send<Buffer> firstRangeKey(
+	static Buffer firstRangeKey(BufferAllocator alloc, Send<Buffer> prefixKey, Send<Buffer> suffixKey, int prefixLength,
-			BufferAllocator alloc,
+			int suffixLength, int extLength) {
-			Send<Buffer> prefixKey,
-			Send<Buffer> suffixKey,
-			int prefixLength,
-			int suffixLength,
-			int extLength) {
 		return zeroFillKeyExt(alloc, prefixKey, suffixKey, prefixLength, suffixLength, extLength);
 	}
 
-	static Send<Buffer> nextRangeKey(
+	static Buffer nextRangeKey(BufferAllocator alloc, Send<Buffer> prefixKey, Send<Buffer> suffixKey, int prefixLength,
-			BufferAllocator alloc,
+			int suffixLength, int extLength) {
-			Send<Buffer> prefixKey,
+		Buffer nonIncremented = zeroFillKeyExt(alloc, prefixKey, suffixKey, prefixLength, suffixLength, extLength);
-			Send<Buffer> suffixKey,
+		incrementPrefix(nonIncremented, prefixLength + suffixLength);
-			int prefixLength,
+		return nonIncremented;
-			int suffixLength,
-			int extLength) {
-		try (Send<Buffer> nonIncremented = zeroFillKeyExt(alloc,
-				prefixKey,
-				suffixKey,
-				prefixLength,
-				suffixLength,
-				extLength
-		)) {
-			return incrementPrefix(alloc, nonIncremented, prefixLength + suffixLength);
-		}
 	}
 
-	protected static Send<Buffer> zeroFillKeyExt(
+	protected static Buffer zeroFillKeyExt(BufferAllocator alloc, Send<Buffer> prefixKeySend, Send<Buffer> suffixKeySend,
-			BufferAllocator alloc,
+			int prefixLength, int suffixLength, int extLength) {
-			Send<Buffer> prefixKeySend,
-			Send<Buffer> suffixKeySend,
-			int prefixLength,
-			int suffixLength,
-			int extLength) {
 		try (var prefixKey = prefixKeySend.receive()) {
 			try (var suffixKey = suffixKeySend.receive()) {
 				assert prefixKey.readableBytes() == prefixLength;
@@ -165,17 +132,14 @@ public class DatabaseMapDictionaryDeep<T, U, US extends DatabaseStage<U>> implem
 				assert suffixLength > 0;
 				assert extLength >= 0;
 
-				try (var ext = alloc.allocate(extLength)) {
+				Buffer result = LLUtils.compositeBuffer(alloc, prefixKey.send(), suffixKey.send());
+				result.ensureWritable(extLength, extLength, true);
 				for (int i = 0; i < extLength; i++) {
-						ext.writeByte((byte) 0);
+					result.writeByte((byte) 0);
 				}
 
-					try (Buffer result = LLUtils.compositeBuffer(alloc, prefixKey.send(), suffixKey.send(), ext.send())
-							.receive()) {
 				assert result.readableBytes() == prefixLength + suffixLength + extLength;
-						return result.send();
+				return result;
-					}
-				}
 			}
 		}
 	}
@@ -185,69 +149,82 @@ public class DatabaseMapDictionaryDeep<T, U, US extends DatabaseStage<U>> implem
 	 */
 	@Deprecated
 	public static <T, U> DatabaseMapDictionaryDeep<T, U, DatabaseStageEntry<U>> simple(LLDictionary dictionary,
-			SerializerFixedBinaryLength<T> keySerializer,
+			SerializerFixedBinaryLength<T> keySerializer, SubStageGetterSingle<U> subStageGetter,
-			SubStageGetterSingle<U> subStageGetter) {
+			Drop<DatabaseMapDictionaryDeep<T, U, DatabaseStageEntry<U>>> drop) {
-		return new DatabaseMapDictionaryDeep<>(dictionary, dictionary.getAllocator().allocate(0).send(),
+		return new DatabaseMapDictionaryDeep<>(dictionary, LLUtils.empty(dictionary.getAllocator()), keySerializer,
-				keySerializer, subStageGetter, 0);
+				subStageGetter, 0, drop);
 	}
 
-	public static <T, U, US extends DatabaseStage<U>> DatabaseMapDictionaryDeep<T, U, US> deepTail(LLDictionary dictionary,
+	public static <T, U, US extends DatabaseStage<U>> DatabaseMapDictionaryDeep<T, U, US> deepTail(
-			SerializerFixedBinaryLength<T> keySerializer,
+			LLDictionary dictionary, SerializerFixedBinaryLength<T> keySerializer, int keyExtLength,
-			int keyExtLength,
+			SubStageGetter<U, US> subStageGetter, Drop<DatabaseMapDictionaryDeep<T, U, US>> drop) {
-			SubStageGetter<U, US> subStageGetter) {
+		return new DatabaseMapDictionaryDeep<>(dictionary, LLUtils.empty(dictionary.getAllocator()), keySerializer,
-		return new DatabaseMapDictionaryDeep<>(dictionary,
+				subStageGetter, keyExtLength, drop);
-				dictionary.getAllocator().allocate(0).send(),
-				keySerializer,
-				subStageGetter,
-				keyExtLength
-		);
 	}
 
-	public static <T, U, US extends DatabaseStage<U>> DatabaseMapDictionaryDeep<T, U, US> deepIntermediate(LLDictionary dictionary,
+	public static <T, U, US extends DatabaseStage<U>> DatabaseMapDictionaryDeep<T, U, US> deepIntermediate(
-			Send<Buffer> prefixKey,
+			LLDictionary dictionary, Send<Buffer> prefixKey, SerializerFixedBinaryLength<T> keySuffixSerializer,
-			SerializerFixedBinaryLength<T> keySuffixSerializer,
+			SubStageGetter<U, US> subStageGetter, int keyExtLength, Drop<DatabaseMapDictionaryDeep<T, U, US>> drop) {
-			SubStageGetter<U, US> subStageGetter,
+		return new DatabaseMapDictionaryDeep<>(dictionary, prefixKey, keySuffixSerializer, subStageGetter,
-			int keyExtLength) {
+				keyExtLength, drop);
-		return new DatabaseMapDictionaryDeep<>(dictionary, prefixKey, keySuffixSerializer, subStageGetter, keyExtLength);
 	}
 
-	protected DatabaseMapDictionaryDeep(LLDictionary dictionary,
+	protected DatabaseMapDictionaryDeep(LLDictionary dictionary, @NotNull Send<Buffer> prefixKeyToReceive,
-			Send<Buffer> prefixKeyToReceive,
+			SerializerFixedBinaryLength<T> keySuffixSerializer, SubStageGetter<U, US> subStageGetter, int keyExtLength,
-			SerializerFixedBinaryLength<T> keySuffixSerializer,
+			Drop<DatabaseMapDictionaryDeep<T, U, US>> drop) {
-			SubStageGetter<U, US> subStageGetter,
+		super(new CloseOnDrop<>(drop));
-			int keyExtLength) {
 		try (var prefixKey = prefixKeyToReceive.receive()) {
 			this.dictionary = dictionary;
 			this.alloc = dictionary.getAllocator();
 			this.subStageGetter = subStageGetter;
 			this.keySuffixSerializer = keySuffixSerializer;
-			this.keyPrefix = prefixKey.copy();
+			assert prefixKey.isAccessible();
-			assert keyPrefix.isAccessible();
+			this.keyPrefixLength = prefixKey.readableBytes();
-			this.keyPrefixLength = keyPrefix.readableBytes();
 			this.keySuffixLength = keySuffixSerializer.getSerializedBinaryLength();
 			this.keyExtLength = keyExtLength;
-			try (Buffer firstKey = firstRangeKey(alloc,
+			Buffer firstKey = firstRangeKey(alloc, LLUtils.copy(alloc, prefixKey), keyPrefixLength,
-					prefixKey.copy().send(),
+					keySuffixLength, keyExtLength);
-					keyPrefixLength,
+			try (firstKey) {
-					keySuffixLength,
+				var nextRangeKey = nextRangeKey(alloc, LLUtils.copy(alloc, prefixKey),
-					keyExtLength
+						keyPrefixLength, keySuffixLength, keyExtLength);
-			).receive().compact()) {
+				try (nextRangeKey) {
-				try (Buffer nextRangeKey = nextRangeKey(alloc,
+					assert prefixKey.isAccessible();
-						prefixKey.copy().send(),
-						keyPrefixLength,
-						keySuffixLength,
-						keyExtLength
-				).receive().compact()) {
-					assert keyPrefix.isAccessible();
 					assert keyPrefixLength == 0 || !LLUtils.equals(firstKey, nextRangeKey);
 					this.range = keyPrefixLength == 0 ? LLRange.all() : LLRange.of(firstKey.send(), nextRangeKey.send());
 					this.rangeMono = LLUtils.lazyRetainRange(this.range);
 					assert subStageKeysConsistency(keyPrefixLength + keySuffixLength + keyExtLength);
 				}
 			}
+
+			this.keyPrefix = prefixKey.send().receive();
 		}
 	}
 
+	private DatabaseMapDictionaryDeep(LLDictionary dictionary,
+			BufferAllocator alloc,
+			SubStageGetter<U, US> subStageGetter,
+			SerializerFixedBinaryLength<T> keySuffixSerializer,
+			int keyPrefixLength,
+			int keySuffixLength,
+			int keyExtLength,
+			Mono<Send<LLRange>> rangeMono,
+			Send<LLRange> range,
+			Send<Buffer> keyPrefix,
+			Drop<DatabaseMapDictionaryDeep<T, U, US>> drop) {
+		super(new CloseOnDrop<>(drop));
+		this.dictionary = dictionary;
+		this.alloc = alloc;
+		this.subStageGetter = subStageGetter;
+		this.keySuffixSerializer = keySuffixSerializer;
+		this.keyPrefixLength = keyPrefixLength;
+		this.keySuffixLength = keySuffixLength;
+		this.keyExtLength = keyExtLength;
+		this.rangeMono = rangeMono;
+
+		this.range = range.receive();
+		this.keyPrefix = keyPrefix.receive();
+	}
+
 	@SuppressWarnings("unused")
 	protected boolean suffixKeyConsistency(int keySuffixLength) {
 		return this.keySuffixLength == keySuffixLength;
@@ -264,21 +241,30 @@ public class DatabaseMapDictionaryDeep<T, U, US extends DatabaseStage<U>> implem
 	}
 
 	/**
-	 * Keep only suffix and ext
+	 * Removes the prefix from the key
 	 */
-	protected Send<Buffer> stripPrefix(Send<Buffer> keyToReceive) {
+	protected void removePrefix(Buffer key) {
-		try (var key = keyToReceive.receive()) {
+		assert key.readableBytes() == keyPrefixLength + keySuffixLength + keyExtLength
-			return key.copy(this.keyPrefixLength, key.readableBytes() - this.keyPrefixLength).send();
+				|| key.readableBytes() == keyPrefixLength + keySuffixLength;
-		}
+		key.readerOffset(key.readerOffset() + this.keyPrefixLength);
+		assert key.readableBytes() == keySuffixLength + keyExtLength
+				|| key.readableBytes() == keySuffixLength;
 	}
 
 	/**
-	 * Add prefix to suffix
+	 * Removes the ext from the key
 	 */
+	protected void removeExt(Buffer key) {
+		assert key.readableBytes() == keyPrefixLength + keySuffixLength + keyExtLength;
+		key.writerOffset(keyPrefixLength + keySuffixLength);
+		assert key.readableBytes() == keyPrefixLength + keySuffixLength;
+	}
+
 	protected Send<Buffer> toKeyWithoutExt(Send<Buffer> suffixKeyToReceive) {
 		try (var suffixKey = suffixKeyToReceive.receive()) {
 			assert suffixKey.readableBytes() == keySuffixLength;
-			try (Buffer result = LLUtils.compositeBuffer(alloc, keyPrefix.copy().send(), suffixKey.send()).receive()) {
+			try (var result = Objects.requireNonNull(LLUtils.compositeBuffer(alloc,
+					LLUtils.copy(alloc, keyPrefix), suffixKey.send()))) {
 				assert result.readableBytes() == keyPrefixLength + keySuffixLength;
 				return result.send();
 			}
@@ -305,10 +291,11 @@ public class DatabaseMapDictionaryDeep<T, U, US extends DatabaseStage<U>> implem
 
 	@Override
 	public Mono<US> at(@Nullable CompositeSnapshot snapshot, T keySuffix) {
+		var suffixKeyWithoutExt = Mono.fromCallable(() -> toKeyWithoutExt(serializeSuffix(keySuffix)));
 		return this.subStageGetter
-				.subStage(dictionary, snapshot, Mono.fromCallable(() -> toKeyWithoutExt(serializeSuffix(keySuffix))))
+				.subStage(dictionary, snapshot, suffixKeyWithoutExt)
 				.transform(LLUtils::handleDiscard)
-				.doOnDiscard(DatabaseStage.class, DatabaseStage::release);
+				.doOnDiscard(DatabaseStage.class, DatabaseStage::close);
 	}
 
 	@Override
@@ -328,11 +315,10 @@ public class DatabaseMapDictionaryDeep<T, U, US extends DatabaseStage<U>> implem
 				.flatMapSequential(groupKeyWithoutExtSend_ -> Mono.using(
 						groupKeyWithoutExtSend_::receive,
 						groupKeyWithoutExtSend -> this.subStageGetter
-								.subStage(dictionary, snapshot, getGroupKeyWithoutExt(groupKeyWithoutExtSend.copy().send()))
+								.subStage(dictionary, snapshot, Mono.fromCallable(() -> groupKeyWithoutExtSend.copy().send()))
 								.<Entry<T, US>>handle((us, sink) -> {
 									try {
-										sink.next(Map.entry(this.deserializeSuffix(getGroupSuffix(groupKeyWithoutExtSend.send())),
+										sink.next(Map.entry(this.deserializeSuffix(getGroupSuffix(groupKeyWithoutExtSend.send())), us));
-												us));
 									} catch (SerializationException ex) {
 										sink.error(ex);
 									}
@@ -342,22 +328,22 @@ public class DatabaseMapDictionaryDeep<T, U, US extends DatabaseStage<U>> implem
 				.transform(LLUtils::handleDiscard);
 	}
 
-	private Send<Buffer> getGroupSuffix(Send<Buffer> groupKeyWithoutExtSend) {
+	private Send<Buffer> getGroupSuffix(Send<Buffer> groupKeyWithoutExt) {
-		try (var groupKeyWithoutExt = groupKeyWithoutExtSend.receive()) {
+		try (var buffer = groupKeyWithoutExt.receive()) {
-			try (var groupSuffix = this.stripPrefix(groupKeyWithoutExt.copy().send()).receive()) {
+			assert subStageKeysConsistency(buffer.readableBytes() + keyExtLength);
-				assert subStageKeysConsistency(groupKeyWithoutExt.readableBytes() + keyExtLength);
+			this.removePrefix(buffer);
-				return groupSuffix.send();
+			assert subStageKeysConsistency(keyPrefixLength + buffer.readableBytes() + keyExtLength);
-			}
+			return buffer.send();
 		}
 	}
 
-	private Mono<Send<Buffer>> getGroupKeyWithoutExt(Send<Buffer> groupKeyWithoutExtSend) {
+	private Send<Buffer> getGroupWithoutExt(Send<Buffer> groupKeyWithExtSend) {
-		return Mono.fromCallable(() -> {
+		try (var buffer = groupKeyWithExtSend.receive()) {
-			try (var groupKeyWithoutExt = groupKeyWithoutExtSend.receive()) {
+			assert subStageKeysConsistency(buffer.readableBytes());
-				assert subStageKeysConsistency(groupKeyWithoutExt.readableBytes() + keyExtLength);
+			this.removeExt(buffer);
-				return groupKeyWithoutExt.send();
+			assert subStageKeysConsistency(buffer.readableBytes() + keyExtLength);
+			return buffer.send();
 		}
-		});
 	}
 
 	private boolean subStageKeysConsistency(int totalKeyLength) {
@@ -401,7 +387,7 @@ public class DatabaseMapDictionaryDeep<T, U, US extends DatabaseStage<U>> implem
 	}
 
 	//todo: temporary wrapper. convert the whole class to buffers
-	protected T deserializeSuffix(Send<Buffer> keySuffixToReceive) throws SerializationException {
+	protected T deserializeSuffix(@NotNull Send<Buffer> keySuffixToReceive) throws SerializationException {
 		try (var keySuffix = keySuffixToReceive.receive()) {
 			assert suffixKeyConsistency(keySuffix.readableBytes());
 			var result = keySuffixSerializer.deserialize(keySuffix.send());
@@ -411,22 +397,54 @@ public class DatabaseMapDictionaryDeep<T, U, US extends DatabaseStage<U>> implem
 	}
 
 	//todo: temporary wrapper. convert the whole class to buffers
+	@NotNull
 	protected Send<Buffer> serializeSuffix(T keySuffix) throws SerializationException {
-		try (Buffer suffixData = keySuffixSerializer.serialize(keySuffix).receive()) {
+		try (var suffixDataToReceive = keySuffixSerializer.serialize(keySuffix)) {
+			try (Buffer suffixData = suffixDataToReceive.receive()) {
 				assert suffixKeyConsistency(suffixData.readableBytes());
 				assert keyPrefix.isAccessible();
 				return suffixData.send();
 			}
 		}
+	}
 
 	@Override
-	public void release() {
+	protected RuntimeException createResourceClosedException() {
-		if (!released) {
+		throw new IllegalStateException("Closed");
-			released = true;
+	}
-			this.range.close();
+
-			this.keyPrefix.close();
+	@Override
-		} else {
+	protected Owned<DatabaseMapDictionaryDeep<T, U, US>> prepareSend() {
-			throw new IllegalReferenceCountException(0, -1);
+		var keyPrefix = this.keyPrefix.send();
+		var range = this.range.send();
+		return drop -> new DatabaseMapDictionaryDeep<>(dictionary, alloc, subStageGetter, keySuffixSerializer,
+				keyPrefixLength, keySuffixLength, keyExtLength, rangeMono, range, keyPrefix, drop);
+	}
+
+	@Override
+	protected void makeInaccessible() {
+		this.keyPrefix = null;
+		this.range = null;
+	}
+
+	private static class CloseOnDrop<T, U, US extends DatabaseStage<U>> implements
+			Drop<DatabaseMapDictionaryDeep<T, U, US>> {
+
+		private final Drop<DatabaseMapDictionaryDeep<T,U,US>> delegate;
+
+		public CloseOnDrop(Drop<DatabaseMapDictionaryDeep<T, U, US>> drop) {
+			this.delegate = drop;
+		}
+
+		@Override
+		public void drop(DatabaseMapDictionaryDeep<T, U, US> obj) {
+			if (obj.range != null) {
+				obj.range.close();
+			}
+			if (obj.keyPrefix != null) {
+				obj.keyPrefix.close();
+			}
+			delegate.drop(obj);
 		}
 	}
 }

src/main/java/it/cavallium/dbengine/database/collections/DatabaseMapDictionaryHashed.java

@@ -2,10 +2,14 @@ package it.cavallium.dbengine.database.collections;
 
 import io.net5.buffer.api.Buffer;
 import io.net5.buffer.api.BufferAllocator;
+import io.net5.buffer.api.Drop;
+import io.net5.buffer.api.Owned;
 import io.net5.buffer.api.Send;
 import it.cavallium.dbengine.client.BadBlock;
 import it.cavallium.dbengine.client.CompositeSnapshot;
 import it.cavallium.dbengine.database.LLDictionary;
+import it.cavallium.dbengine.database.LLUtils;
+import it.cavallium.dbengine.database.LiveResourceSupport;
 import it.cavallium.dbengine.database.UpdateMode;
 import it.cavallium.dbengine.database.serialization.Serializer;
 import it.cavallium.dbengine.database.serialization.SerializerFixedBinaryLength;
@@ -23,18 +27,23 @@ import reactor.core.publisher.Flux;
 import reactor.core.publisher.Mono;
 
 @SuppressWarnings("unused")
-public class DatabaseMapDictionaryHashed<T, U, TH> implements DatabaseStageMap<T, U, DatabaseStageEntry<U>> {
+public class DatabaseMapDictionaryHashed<T, U, TH> extends
+		LiveResourceSupport<DatabaseStage<Map<T, U>>, DatabaseMapDictionaryHashed<T, U, TH>>
+		implements DatabaseStageMap<T, U, DatabaseStageEntry<U>> {
 
 	private final BufferAllocator alloc;
-	private final DatabaseMapDictionary<TH, ObjectArraySet<Entry<T, U>>> subDictionary;
 	private final Function<T, TH> keySuffixHashFunction;
 
+	private DatabaseMapDictionary<TH, ObjectArraySet<Entry<T, U>>> subDictionary;
+
 	protected DatabaseMapDictionaryHashed(LLDictionary dictionary,
-			Send<Buffer> prefixKey,
+			@NotNull Send<Buffer> prefixKey,
 			Serializer<T> keySuffixSerializer,
 			Serializer<U> valueSerializer,
 			Function<T, TH> keySuffixHashFunction,
-			SerializerFixedBinaryLength<TH> keySuffixHashSerializer) {
+			SerializerFixedBinaryLength<TH> keySuffixHashSerializer,
+			Drop<DatabaseMapDictionaryHashed<T, U, TH>> drop) {
+		super(new DatabaseMapDictionaryHashed.CloseOnDrop<>(drop));
 		if (dictionary.getUpdateMode().block() != UpdateMode.ALLOW) {
 			throw new IllegalArgumentException("Hashed maps only works when UpdateMode is ALLOW");
 		}
@@ -43,26 +52,36 @@ public class DatabaseMapDictionaryHashed<T, U, TH> implements DatabaseStageMap<T
 				= new ValueWithHashSerializer<>(alloc, keySuffixSerializer, valueSerializer);
 		ValuesSetSerializer<Entry<T, U>> valuesSetSerializer
 				= new ValuesSetSerializer<>(alloc, valueWithHashSerializer);
-		this.subDictionary = DatabaseMapDictionary.tail(dictionary,
+		this.subDictionary = DatabaseMapDictionary.tail(dictionary, prefixKey, keySuffixHashSerializer,
-				prefixKey,
+				valuesSetSerializer, d -> {});
-				keySuffixHashSerializer,
-				valuesSetSerializer
-		);
 		this.keySuffixHashFunction = keySuffixHashFunction;
 	}
 
+	private DatabaseMapDictionaryHashed(BufferAllocator alloc,
+			Function<T, TH> keySuffixHashFunction,
+			Send<DatabaseStage<Map<TH, ObjectArraySet<Entry<T, U>>>>> subDictionary,
+			Drop<DatabaseMapDictionaryHashed<T, U, TH>> drop) {
+		super(new CloseOnDrop<>(drop));
+		this.alloc = alloc;
+		this.keySuffixHashFunction = keySuffixHashFunction;
+
+		this.subDictionary = (DatabaseMapDictionary<TH, ObjectArraySet<Entry<T, U>>>) subDictionary.receive();
+	}
+
 	public static <T, U, UH> DatabaseMapDictionaryHashed<T, U, UH> simple(LLDictionary dictionary,
 			Serializer<T> keySerializer,
 			Serializer<U> valueSerializer,
 			Function<T, UH> keyHashFunction,
-			SerializerFixedBinaryLength<UH> keyHashSerializer) {
+			SerializerFixedBinaryLength<UH> keyHashSerializer,
+			Drop<DatabaseMapDictionaryHashed<T, U, UH>> drop) {
 		return new DatabaseMapDictionaryHashed<>(
 				dictionary,
-				dictionary.getAllocator().allocate(0).send(),
+				LLUtils.empty(dictionary.getAllocator()),
 				keySerializer,
 				valueSerializer,
 				keyHashFunction,
-				keyHashSerializer
+				keyHashSerializer,
+				drop
 		);
 	}
 
@@ -71,13 +90,15 @@ public class DatabaseMapDictionaryHashed<T, U, TH> implements DatabaseStageMap<T
 			Serializer<T> keySuffixSerializer,
 			Serializer<U> valueSerializer,
 			Function<T, UH> keySuffixHashFunction,
-			SerializerFixedBinaryLength<UH> keySuffixHashSerializer) {
+			SerializerFixedBinaryLength<UH> keySuffixHashSerializer,
+			Drop<DatabaseMapDictionaryHashed<T, U, UH>> drop) {
 		return new DatabaseMapDictionaryHashed<>(dictionary,
 				prefixKey,
 				keySuffixSerializer,
 				valueSerializer,
 				keySuffixHashFunction,
-				keySuffixHashSerializer
+				keySuffixHashSerializer,
+				drop
 		);
 	}
 
@@ -124,11 +145,6 @@ public class DatabaseMapDictionaryHashed<T, U, TH> implements DatabaseStageMap<T
 		return subDictionary.clearAndGetStatus();
 	}
 
-	@Override
-	public Mono<Void> close() {
-		return subDictionary.close();
-	}
-
 	@Override
 	public Mono<Boolean> isEmpty(@Nullable CompositeSnapshot snapshot) {
 		return subDictionary.isEmpty(snapshot);
@@ -144,11 +160,6 @@ public class DatabaseMapDictionaryHashed<T, U, TH> implements DatabaseStageMap<T
 		return this.subDictionary.badBlocks();
 	}
 
-	@Override
-	public void release() {
-		this.subDictionary.release();
-	}
-
 	@Override
 	public Mono<DatabaseStageEntry<U>> at(@Nullable CompositeSnapshot snapshot, T key) {
 		return this
@@ -159,7 +170,7 @@ public class DatabaseMapDictionaryHashed<T, U, TH> implements DatabaseStageMap<T
 	private Mono<DatabaseSingleBucket<T, U, TH>> atPrivate(@Nullable CompositeSnapshot snapshot, T key, TH hash) {
 		return subDictionary
 				.at(snapshot, hash)
-				.map(entry -> new DatabaseSingleBucket<>(entry, key));
+				.map(entry -> new DatabaseSingleBucket<>(entry, key, d -> {}));
 	}
 
 	@Override
@@ -192,13 +203,11 @@ public class DatabaseMapDictionaryHashed<T, U, TH> implements DatabaseStageMap<T
 	@Override
 	public Flux<Entry<T, U>> setAllValuesAndGetPrevious(Flux<Entry<T, U>> entries) {
 		return entries
-				.flatMap(entry -> Flux.usingWhen(
+				.flatMap(entry -> LLUtils.usingResource(this.at(null, entry.getKey()),
-						this.at(null, entry.getKey()),
 						stage -> stage
 								.setAndGetPrevious(entry.getValue())
-								.map(prev -> Map.entry(entry.getKey(), prev)),
+								.map(prev -> Map.entry(entry.getKey(), prev)), true)
-						stage -> Mono.fromRunnable(stage::release)
+				);
-				));
 	}
 
 	@Override
@@ -296,4 +305,37 @@ public class DatabaseMapDictionaryHashed<T, U, TH> implements DatabaseStageMap<T
 			return null;
 		}
 	}
+
+	@Override
+	protected RuntimeException createResourceClosedException() {
+		throw new IllegalStateException("Closed");
+	}
+
+	@Override
+	protected Owned<DatabaseMapDictionaryHashed<T, U, TH>> prepareSend() {
+		var subDictionary = this.subDictionary.send();
+		return drop -> new DatabaseMapDictionaryHashed<>(alloc, keySuffixHashFunction, subDictionary, drop);
+	}
+
+	@Override
+	protected void makeInaccessible() {
+		this.subDictionary = null;
+	}
+
+	private static class CloseOnDrop<T, U, TH> implements Drop<DatabaseMapDictionaryHashed<T,U,TH>> {
+
+		private final Drop<DatabaseMapDictionaryHashed<T,U,TH>> delegate;
+
+		public CloseOnDrop(Drop<DatabaseMapDictionaryHashed<T,U,TH>> drop) {
+			this.delegate = drop;
+		}
+
+		@Override
+		public void drop(DatabaseMapDictionaryHashed<T, U, TH> obj) {
+			if (obj.subDictionary != null) {
+				obj.subDictionary.close();
+			}
+			delegate.drop(obj);
+		}
+	}
 }

src/main/java/it/cavallium/dbengine/database/collections/DatabaseSetDictionary.java

@@ -1,9 +1,11 @@
 package it.cavallium.dbengine.database.collections;
 
 import io.net5.buffer.api.Buffer;
+import io.net5.buffer.api.Drop;
 import io.net5.buffer.api.Send;
 import it.cavallium.dbengine.client.CompositeSnapshot;
 import it.cavallium.dbengine.database.LLDictionary;
+import it.cavallium.dbengine.database.LLUtils;
 import it.cavallium.dbengine.database.collections.DatabaseEmpty.Nothing;
 import it.cavallium.dbengine.database.serialization.SerializerFixedBinaryLength;
 import java.util.HashMap;
@@ -17,21 +19,22 @@ public class DatabaseSetDictionary<T> extends DatabaseMapDictionary<T, Nothing>
 
 	protected DatabaseSetDictionary(LLDictionary dictionary,
 			Send<Buffer> prefixKey,
-			SerializerFixedBinaryLength<T> keySuffixSerializer) {
+			SerializerFixedBinaryLength<T> keySuffixSerializer,
-		super(dictionary, prefixKey, keySuffixSerializer, DatabaseEmpty.nothingSerializer(dictionary.getAllocator()));
+			Drop<DatabaseMapDictionaryDeep<T, Nothing, DatabaseStageEntry<Nothing>>> drop) {
+		super(dictionary, prefixKey, keySuffixSerializer, DatabaseEmpty.nothingSerializer(dictionary.getAllocator()), drop);
 	}
 
 	public static <T> DatabaseSetDictionary<T> simple(LLDictionary dictionary,
-			SerializerFixedBinaryLength<T> keySerializer) {
+			SerializerFixedBinaryLength<T> keySerializer,
-		try (var buf = dictionary.getAllocator().allocate(0)) {
+			Drop<DatabaseMapDictionaryDeep<T, Nothing, DatabaseStageEntry<Nothing>>> drop) {
-			return new DatabaseSetDictionary<>(dictionary, buf.send(), keySerializer);
+		return new DatabaseSetDictionary<>(dictionary, LLUtils.empty(dictionary.getAllocator()), keySerializer, drop);
-		}
 	}
 
 	public static <T> DatabaseSetDictionary<T> tail(LLDictionary dictionary,
 			Send<Buffer> prefixKey,
-			SerializerFixedBinaryLength<T> keySuffixSerializer) {
+			SerializerFixedBinaryLength<T> keySuffixSerializer,
-		return new DatabaseSetDictionary<>(dictionary, prefixKey, keySuffixSerializer);
+			Drop<DatabaseMapDictionaryDeep<T, Nothing, DatabaseStageEntry<Nothing>>> drop) {
+		return new DatabaseSetDictionary<>(dictionary, prefixKey, keySuffixSerializer, drop);
 	}
 
 	public Mono<Set<T>> getKeySet(@Nullable CompositeSnapshot snapshot) {

src/main/java/it/cavallium/dbengine/database/collections/DatabaseSetDictionaryHashed.java

@@ -1,9 +1,11 @@
 package it.cavallium.dbengine.database.collections;
 
 import io.net5.buffer.api.Buffer;
+import io.net5.buffer.api.Drop;
 import io.net5.buffer.api.Send;
 import it.cavallium.dbengine.client.CompositeSnapshot;
 import it.cavallium.dbengine.database.LLDictionary;
+import it.cavallium.dbengine.database.LLUtils;
 import it.cavallium.dbengine.database.collections.DatabaseEmpty.Nothing;
 import it.cavallium.dbengine.database.serialization.Serializer;
 import it.cavallium.dbengine.database.serialization.SerializerFixedBinaryLength;
@@ -11,6 +13,7 @@ import java.util.HashMap;
 import java.util.Map;
 import java.util.Set;
 import java.util.function.Function;
+import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 import reactor.core.publisher.Mono;
 
@@ -18,28 +21,32 @@ import reactor.core.publisher.Mono;
 public class DatabaseSetDictionaryHashed<T, TH> extends DatabaseMapDictionaryHashed<T, Nothing, TH> {
 
 	protected DatabaseSetDictionaryHashed(LLDictionary dictionary,
-			Send<Buffer> prefixKey,
+			@NotNull Send<Buffer> prefixKey,
 			Serializer<T> keySuffixSerializer,
 			Function<T, TH> keySuffixHashFunction,
-			SerializerFixedBinaryLength<TH> keySuffixHashSerializer) {
+			SerializerFixedBinaryLength<TH> keySuffixHashSerializer,
+			Drop<DatabaseMapDictionaryHashed<T, Nothing, TH>> drop) {
 		super(dictionary,
 				prefixKey,
 				keySuffixSerializer,
 				DatabaseEmpty.nothingSerializer(dictionary.getAllocator()),
 				keySuffixHashFunction,
-				keySuffixHashSerializer
+				keySuffixHashSerializer,
+				drop
 		);
 	}
 
 	public static <T, TH> DatabaseSetDictionaryHashed<T, TH> simple(LLDictionary dictionary,
 			Serializer<T> keySerializer,
 			Function<T, TH> keyHashFunction,
-			SerializerFixedBinaryLength<TH> keyHashSerializer) {
+			SerializerFixedBinaryLength<TH> keyHashSerializer,
+			Drop<DatabaseMapDictionaryHashed<T, Nothing, TH>> drop) {
 		return new DatabaseSetDictionaryHashed<>(dictionary,
-				dictionary.getAllocator().allocate(0).send(),
+				LLUtils.empty(dictionary.getAllocator()),
 				keySerializer,
 				keyHashFunction,
-				keyHashSerializer
+				keyHashSerializer,
+				drop
 		);
 	}
 
@@ -47,12 +54,13 @@ public class DatabaseSetDictionaryHashed<T, TH> extends DatabaseMapDictionaryHas
 			Send<Buffer> prefixKey,
 			Serializer<T> keySuffixSerializer,
 			Function<T, TH> keyHashFunction,
-			SerializerFixedBinaryLength<TH> keyHashSerializer) {
+			SerializerFixedBinaryLength<TH> keyHashSerializer, Drop<DatabaseMapDictionaryHashed<T, Nothing, TH>> drop) {
 		return new DatabaseSetDictionaryHashed<>(dictionary,
 				prefixKey,
 				keySuffixSerializer,
 				keyHashFunction,
-				keyHashSerializer
+				keyHashSerializer,
+				drop
 		);
 	}
 

src/main/java/it/cavallium/dbengine/database/collections/DatabaseSingle.java

@@ -1,6 +1,8 @@
 package it.cavallium.dbengine.database.collections;
 
 import io.net5.buffer.api.Buffer;
+import io.net5.buffer.api.Drop;
+import io.net5.buffer.api.Owned;
 import io.net5.buffer.api.Send;
 import io.net5.buffer.api.internal.ResourceSupport;
 import it.cavallium.dbengine.client.BadBlock;
@@ -20,14 +22,18 @@ import reactor.core.publisher.Flux;
 import reactor.core.publisher.Mono;
 import reactor.core.publisher.SynchronousSink;
 
-public class DatabaseSingle<U> implements DatabaseStageEntry<U> {
+public class DatabaseSingle<U> extends ResourceSupport<DatabaseStage<U>, DatabaseSingle<U>> implements
+		DatabaseStageEntry<U> {
 
 	private final LLDictionary dictionary;
-	private final Buffer key;
 	private final Mono<Send<Buffer>> keyMono;
 	private final Serializer<U> serializer;
 
-	public DatabaseSingle(LLDictionary dictionary, Send<Buffer> key, Serializer<U> serializer) {
+	private Buffer key;
+
+	public DatabaseSingle(LLDictionary dictionary, Send<Buffer> key, Serializer<U> serializer,
+			Drop<DatabaseSingle<U>> drop) {
+		super(new CloseOnDrop<>(drop));
 		try (key) {
 			this.dictionary = dictionary;
 			this.key = key.receive();
@@ -124,13 +130,41 @@ public class DatabaseSingle<U> implements DatabaseStageEntry<U> {
 				.isRangeEmpty(resolveSnapshot(snapshot), keyMono.map(LLRange::single).map(ResourceSupport::send));
 	}
 
-	@Override
-	public void release() {
-		key.close();
-	}
-
 	@Override
 	public Flux<BadBlock> badBlocks() {
 		return dictionary.badBlocks(keyMono.map(LLRange::single).map(ResourceSupport::send));
 	}
+
+	@Override
+	protected RuntimeException createResourceClosedException() {
+		throw new IllegalStateException("Closed");
+	}
+
+	@Override
+	protected Owned<DatabaseSingle<U>> prepareSend() {
+		var key = this.key.send();
+		return drop -> new DatabaseSingle<>(dictionary, key, serializer, drop);
+	}
+
+	@Override
+	protected void makeInaccessible() {
+		this.key = null;
+	}
+
+	private static class CloseOnDrop<U> implements Drop<DatabaseSingle<U>> {
+
+		private final Drop<DatabaseSingle<U>> delegate;
+
+		public CloseOnDrop(Drop<DatabaseSingle<U>> drop) {
+			this.delegate = drop;
+		}
+
+		@Override
+		public void drop(DatabaseSingle<U> obj) {
+			if (obj.key != null) {
+				obj.key.close();
+			}
+			delegate.drop(obj);
+		}
+	}
 }

src/main/java/it/cavallium/dbengine/database/collections/DatabaseSingleBucket.java

@@ -1,10 +1,14 @@
 package it.cavallium.dbengine.database.collections;
 
+import io.net5.buffer.api.Drop;
+import io.net5.buffer.api.Owned;
+import io.net5.buffer.api.Send;
 import it.cavallium.dbengine.client.BadBlock;
 import it.cavallium.dbengine.client.CompositeSnapshot;
 import it.cavallium.dbengine.database.Column;
 import it.cavallium.dbengine.database.Delta;
 import it.cavallium.dbengine.database.LLUtils;
+import it.cavallium.dbengine.database.LiveResourceSupport;
 import it.cavallium.dbengine.database.UpdateReturnMode;
 import it.cavallium.dbengine.database.serialization.SerializationFunction;
 import it.unimi.dsi.fastutil.objects.ObjectArraySet;
@@ -23,14 +27,26 @@ import reactor.core.publisher.Flux;
 import reactor.core.publisher.Mono;
 
 @SuppressWarnings("unused")
-public class DatabaseSingleBucket<K, V, TH> implements DatabaseStageEntry<V> {
+public class DatabaseSingleBucket<K, V, TH>
+		extends LiveResourceSupport<DatabaseStage<V>, DatabaseSingleBucket<K, V, TH>>
+		implements DatabaseStageEntry<V> {
 
-	private final DatabaseStageEntry<ObjectArraySet<Entry<K, V>>> bucketStage;
 	private final K key;
 
-	public DatabaseSingleBucket(DatabaseStageEntry<ObjectArraySet<Entry<K, V>>> bucketStage, K key) {
+	private DatabaseStageEntry<ObjectArraySet<Entry<K, V>>> bucketStage;
-		this.bucketStage = bucketStage;
+
+	public DatabaseSingleBucket(DatabaseStageEntry<ObjectArraySet<Entry<K, V>>> bucketStage, K key,
+			Drop<DatabaseSingleBucket<K, V, TH>> drop) {
+		super(new CloseOnDrop<>(drop));
 		this.key = key;
+		this.bucketStage = bucketStage;
+	}
+
+	private DatabaseSingleBucket(Send<DatabaseStage<ObjectArraySet<Entry<K, V>>>> bucketStage, K key,
+			Drop<DatabaseSingleBucket<K, V, TH>> drop) {
+		super(new CloseOnDrop<>(drop));
+		this.key = key;
+		this.bucketStage = (DatabaseStageEntry<ObjectArraySet<Entry<K, V>>>) bucketStage.receive();
 	}
 
 	@Override
@@ -77,7 +93,8 @@ public class DatabaseSingleBucket<K, V, TH> implements DatabaseStageEntry<V> {
 	}
 
 	@Override
-	public Mono<Delta<V>> updateAndGetDelta(SerializationFunction<@Nullable V, @Nullable V> updater, boolean existsAlmostCertainly) {
+	public Mono<Delta<V>> updateAndGetDelta(SerializationFunction<@Nullable V, @Nullable V> updater,
+			boolean existsAlmostCertainly) {
 		return bucketStage
 				.updateAndGetDelta(oldBucket -> {
 					V oldValue = extractValue(oldBucket);
@@ -106,11 +123,6 @@ public class DatabaseSingleBucket<K, V, TH> implements DatabaseStageEntry<V> {
 		return this.updateAndGetDelta(prev -> null).map(LLUtils::isDeltaChanged);
 	}
 
-	@Override
-	public Mono<Void> close() {
-		return bucketStage.close();
-	}
-
 	@Override
 	public Mono<Long> leavesCount(@Nullable CompositeSnapshot snapshot, boolean fast) {
 		return this.get(snapshot).map(prev -> 1L).defaultIfEmpty(0L);
@@ -131,11 +143,6 @@ public class DatabaseSingleBucket<K, V, TH> implements DatabaseStageEntry<V> {
 		return bucketStage.badBlocks();
 	}
 
-	@Override
-	public void release() {
-		bucketStage.release();
-	}
-
 	private Mono<V> extractValueTransformation(Set<Entry<K, V>> entries) {
 		return Mono.fromCallable(() -> extractValue(entries));
 	}
@@ -193,4 +200,38 @@ public class DatabaseSingleBucket<K, V, TH> implements DatabaseStageEntry<V> {
 			return null;
 		}
 	}
+
+	@Override
+	protected RuntimeException createResourceClosedException() {
+		throw new IllegalStateException("Closed");
+	}
+
+	@Override
+	protected Owned<DatabaseSingleBucket<K, V, TH>> prepareSend() {
+		var bucketStage = this.bucketStage.send();
+		return drop -> new DatabaseSingleBucket<>(bucketStage, key, drop);
+	}
+
+	@Override
+	protected void makeInaccessible() {
+		this.bucketStage = null;
+	}
+
+	private static class CloseOnDrop<K, V, TH> implements
+			Drop<DatabaseSingleBucket<K, V, TH>> {
+
+		private final Drop<DatabaseSingleBucket<K, V, TH>> delegate;
+
+		public CloseOnDrop(Drop<DatabaseSingleBucket<K, V, TH>> drop) {
+			this.delegate = drop;
+		}
+
+		@Override
+		public void drop(DatabaseSingleBucket<K, V, TH> obj) {
+			if (obj.bucketStage != null) {
+				obj.bucketStage.close();
+			}
+			delegate.drop(obj);
+		}
+	}
 }

src/main/java/it/cavallium/dbengine/database/collections/DatabaseSingleMapped.java

@@ -1,5 +1,9 @@
 package it.cavallium.dbengine.database.collections;
 
+import io.net5.buffer.api.Drop;
+import io.net5.buffer.api.Owned;
+import io.net5.buffer.api.Send;
+import io.net5.buffer.api.internal.ResourceSupport;
 import it.cavallium.dbengine.client.BadBlock;
 import it.cavallium.dbengine.client.CompositeSnapshot;
 import it.cavallium.dbengine.client.Mapper;
@@ -14,16 +18,28 @@ import reactor.core.publisher.Mono;
 import reactor.core.publisher.SynchronousSink;
 
 @SuppressWarnings("unused")
-public class DatabaseSingleMapped<A, B> implements DatabaseStageEntry<A> {
+public class DatabaseSingleMapped<A, B> extends ResourceSupport<DatabaseStage<A>, DatabaseSingleMapped<A, B>>
+		implements DatabaseStageEntry<A> {
 
-	private final DatabaseStageEntry<B> serializedSingle;
 	private final Mapper<A, B> mapper;
 
-	public DatabaseSingleMapped(DatabaseStageEntry<B> serializedSingle, Mapper<A, B> mapper) {
+	private DatabaseStageEntry<B> serializedSingle;
+
+	public DatabaseSingleMapped(DatabaseStageEntry<B> serializedSingle, Mapper<A, B> mapper,
+			Drop<DatabaseSingleMapped<A, B>> drop) {
+		super(new CloseOnDrop<>(drop));
 		this.serializedSingle = serializedSingle;
 		this.mapper = mapper;
 	}
 
+	private DatabaseSingleMapped(Send<DatabaseStage<B>> serializedSingle, Mapper<A, B> mapper,
+			Drop<DatabaseSingleMapped<A, B>> drop) {
+		super(new CloseOnDrop<>(drop));
+		this.mapper = mapper;
+
+		this.serializedSingle = (DatabaseStageEntry<B>) serializedSingle.receive();
+	}
+
 	private void deserializeSink(B value, SynchronousSink<A> sink) {
 		try {
 			sink.next(this.unMap(value));
@@ -107,11 +123,6 @@ public class DatabaseSingleMapped<A, B> implements DatabaseStageEntry<A> {
 		return serializedSingle.clearAndGetStatus();
 	}
 
-	@Override
-	public Mono<Void> close() {
-		return serializedSingle.close();
-	}
-
 	@Override
 	public Mono<Long> leavesCount(@Nullable CompositeSnapshot snapshot, boolean fast) {
 		return serializedSingle.leavesCount(snapshot, fast);
@@ -132,11 +143,6 @@ public class DatabaseSingleMapped<A, B> implements DatabaseStageEntry<A> {
 		return this.serializedSingle.badBlocks();
 	}
 
-	@Override
-	public void release() {
-		serializedSingle.release();
-	}
-
 	//todo: temporary wrapper. convert the whole class to buffers
 	private A unMap(B bytes) throws SerializationException {
 		return mapper.unmap(bytes);
@@ -146,4 +152,37 @@ public class DatabaseSingleMapped<A, B> implements DatabaseStageEntry<A> {
 	private B map(A bytes) throws SerializationException {
 		return mapper.map(bytes);
 	}
+
+	@Override
+	protected RuntimeException createResourceClosedException() {
+		throw new IllegalStateException("Closed");
+	}
+
+	@Override
+	protected Owned<DatabaseSingleMapped<A, B>> prepareSend() {
+		var serializedSingle = this.serializedSingle.send();
+		return drop -> new DatabaseSingleMapped<>(serializedSingle, mapper, drop);
+	}
+
+	@Override
+	protected void makeInaccessible() {
+		this.serializedSingle = null;
+	}
+
+	private static class CloseOnDrop<A, B> implements Drop<DatabaseSingleMapped<A, B>> {
+
+		private final Drop<DatabaseSingleMapped<A, B>> delegate;
+
+		public CloseOnDrop(Drop<DatabaseSingleMapped<A, B>> drop) {
+			this.delegate = drop;
+		}
+
+		@Override
+		public void drop(DatabaseSingleMapped<A, B> obj) {
+			if (obj.serializedSingle != null) {
+				obj.serializedSingle.close();
+			}
+			delegate.drop(obj);
+		}
+	}
 }

src/main/java/it/cavallium/dbengine/database/collections/DatabaseStage.java

@@ -1,5 +1,6 @@
 package it.cavallium.dbengine.database.collections;
 
+import io.net5.buffer.api.Resource;
 import it.cavallium.dbengine.client.BadBlock;
 import it.cavallium.dbengine.client.CompositeSnapshot;
 import it.cavallium.dbengine.database.Delta;
@@ -12,7 +13,7 @@ import org.jetbrains.annotations.Nullable;
 import reactor.core.publisher.Flux;
 import reactor.core.publisher.Mono;
 
-public interface DatabaseStage<T> extends DatabaseStageWithEntry<T> {
+public interface DatabaseStage<T> extends DatabaseStageWithEntry<T>, Resource<DatabaseStage<T>> {
 
 	default Mono<T> get(@Nullable CompositeSnapshot snapshot) {
 		return get(snapshot, false);
@@ -74,12 +75,6 @@ public interface DatabaseStage<T> extends DatabaseStageWithEntry<T> {
 		return clearAndGetPrevious().map(Objects::nonNull).defaultIfEmpty(false);
 	}
 
-	void release();
-
-	default Mono<Void> close() {
-		return Mono.empty();
-	}
-
 	/**
 	 * Count all the elements.
 	 * If it's a nested collection the count will include all the children recursively

src/main/java/it/cavallium/dbengine/database/collections/DatabaseStageEntry.java

@@ -1,5 +1,6 @@
 package it.cavallium.dbengine.database.collections;
 
+import io.net5.buffer.api.Resource;
 import it.cavallium.dbengine.client.BadBlock;
 import reactor.core.publisher.Flux;
 

src/main/java/it/cavallium/dbengine/database/collections/DatabaseStageMap.java

@@ -34,11 +34,8 @@ public interface DatabaseStageMap<T, U, US extends DatabaseStage<U>> extends Dat
 	Mono<US> at(@Nullable CompositeSnapshot snapshot, T key);
 
 	default Mono<U> getValue(@Nullable CompositeSnapshot snapshot, T key, boolean existsAlmostCertainly) {
-		return Mono.usingWhen(
+		return LLUtils.usingResource(this.at(snapshot, key),
-				this.at(snapshot, key),
+				stage -> stage.get(snapshot, existsAlmostCertainly), true);
-				stage -> stage.get(snapshot, existsAlmostCertainly),
-				stage -> Mono.fromRunnable(stage::release)
-		);
 	}
 
 	default Mono<U> getValue(@Nullable CompositeSnapshot snapshot, T key) {
@@ -50,11 +47,8 @@ public interface DatabaseStageMap<T, U, US extends DatabaseStage<U>> extends Dat
 	}
 
 	default Mono<Void> putValue(T key, U value) {
-		return Mono.usingWhen(
+		return LLUtils.usingResource(at(null, key).single(),
-				at(null, key).single(),
+				stage -> stage.set(value), true);
-				stage -> stage.set(value),
-				stage -> Mono.fromRunnable(stage::release)
-		);
 	}
 
 	Mono<UpdateMode> getUpdateMode();
@@ -63,11 +57,8 @@ public interface DatabaseStageMap<T, U, US extends DatabaseStage<U>> extends Dat
 			UpdateReturnMode updateReturnMode,
 			boolean existsAlmostCertainly,
 			SerializationFunction<@Nullable U, @Nullable U> updater) {
-		return Mono.usingWhen(
+		return LLUtils.usingResource(this.at(null, key).single(),
-				this.at(null, key).single(),
+				stage -> stage.update(updater, updateReturnMode, existsAlmostCertainly), true);
-				stage -> stage.update(updater, updateReturnMode, existsAlmostCertainly),
-				stage -> Mono.fromRunnable(stage::release)
-		);
 	}
 
 	default <X> Flux<ExtraKeyOperationResult<T, X>> updateMulti(Flux<Tuple2<T, X>> entries,
@@ -94,11 +85,8 @@ public interface DatabaseStageMap<T, U, US extends DatabaseStage<U>> extends Dat
 	default Mono<Delta<U>> updateValueAndGetDelta(T key,
 			boolean existsAlmostCertainly,
 			SerializationFunction<@Nullable U, @Nullable U> updater) {
-		return Mono.usingWhen(
+		return LLUtils.usingResource(this.at(null, key).single(),
-				this.at(null, key).single(),
+				stage -> stage.updateAndGetDelta(updater, existsAlmostCertainly), true);
-				stage -> stage.updateAndGetDelta(updater, existsAlmostCertainly),
-				stage -> Mono.fromRunnable(stage::release)
-		);
 	}
 
 	default Mono<Delta<U>> updateValueAndGetDelta(T key, SerializationFunction<@Nullable U, @Nullable U> updater) {
@@ -106,22 +94,14 @@ public interface DatabaseStageMap<T, U, US extends DatabaseStage<U>> extends Dat
 	}
 
 	default Mono<U> putValueAndGetPrevious(T key, U value) {
-		return Mono.usingWhen(
+		return LLUtils.usingResource(at(null, key).single(), stage -> stage.setAndGetPrevious(value), true);
-				at(null, key).single(),
-				stage -> stage.setAndGetPrevious(value),
-				stage -> Mono.fromRunnable(stage::release)
-		);
 	}
 
 	/**
 	 * @return true if the key was associated with any value, false if the key didn't exist.
 	 */
 	default Mono<Boolean> putValueAndGetChanged(T key, U value) {
-		return Mono.usingWhen(
+		return LLUtils.usingResource(at(null, key).single(), stage -> stage.setAndGetChanged(value), true).single();
-				at(null, key).single(),
-				stage -> stage.setAndGetChanged(value),
-				stage -> Mono.fromRunnable(stage::release)
-		).single();
 	}
 
 	default Mono<Void> remove(T key) {
@@ -129,11 +109,7 @@ public interface DatabaseStageMap<T, U, US extends DatabaseStage<U>> extends Dat
 	}
 
 	default Mono<U> removeAndGetPrevious(T key) {
-		return Mono.usingWhen(
+		return LLUtils.usingResource(at(null, key), DatabaseStage::clearAndGetPrevious, true);
-				at(null, key),
-				DatabaseStage::clearAndGetPrevious,
-				stage -> Mono.fromRunnable(stage::release)
-		);
 	}
 
 	default Mono<Boolean> removeAndGetStatus(T key) {
@@ -175,11 +151,11 @@ public interface DatabaseStageMap<T, U, US extends DatabaseStage<U>> extends Dat
 	default Flux<Entry<T, U>> getAllValues(@Nullable CompositeSnapshot snapshot) {
 		return this
 				.getAllStages(snapshot)
-				.flatMapSequential(entry -> entry
+				.flatMapSequential(stage -> stage
 						.getValue()
 						.get(snapshot, true)
-						.map(value -> Map.entry(entry.getKey(), value))
+						.map(value -> Map.entry(stage.getKey(), value))
-						.doAfterTerminate(() -> entry.getValue().release())
+						.doFinally(s -> stage.getValue().close())
 				);
 	}
 
@@ -193,7 +169,8 @@ public interface DatabaseStageMap<T, U, US extends DatabaseStage<U>> extends Dat
 		return setAllValues(Flux.empty());
 	}
 
-	default Mono<Void> replaceAllValues(boolean canKeysChange, Function<Entry<T, U>, Mono<Entry<T, U>>> entriesReplacer) {
+	default Mono<Void> replaceAllValues(boolean canKeysChange, Function<Entry<T, U>,
+			Mono<Entry<T, U>>> entriesReplacer) {
 		if (canKeysChange) {
 			return this.setAllValues(this.getAllValues(null).flatMap(entriesReplacer)).then();
 		} else {
@@ -202,7 +179,11 @@ public interface DatabaseStageMap<T, U, US extends DatabaseStage<U>> extends Dat
 					.flatMap(entriesReplacer)
 					.flatMap(replacedEntry -> this
 							.at(null, replacedEntry.getKey())
-							.flatMap(v -> v.set(replacedEntry.getValue()).doAfterTerminate(v::release)))
+							.flatMap(stage -> stage
+									.set(replacedEntry.getValue())
+									.doFinally(s -> stage.close())
+							)
+					)
 					.then();
 		}
 	}
@@ -210,9 +191,8 @@ public interface DatabaseStageMap<T, U, US extends DatabaseStage<U>> extends Dat
 	default Mono<Void> replaceAll(Function<Entry<T, US>, Mono<Void>> entriesReplacer) {
 		return this
 				.getAllStages(null)
-				.flatMap(stage -> Mono
+				.flatMap(stage -> entriesReplacer.apply(stage)
-						.defer(() -> entriesReplacer.apply(stage))
+						.doFinally(s -> stage.getValue().close())
-						.doAfterTerminate(() -> stage.getValue().release())
 				)
 				.then();
 	}
@@ -221,14 +201,15 @@ public interface DatabaseStageMap<T, U, US extends DatabaseStage<U>> extends Dat
 	default Mono<Map<T, U>> setAndGetPrevious(Map<T, U> value) {
 		return this
 				.setAllValuesAndGetPrevious(Flux.fromIterable(Map.copyOf(value).entrySet()))
-				.collectMap(Entry::getKey, Entry::getValue, HashMap::new);
+				.collectMap(Entry::getKey, Entry::getValue, HashMap::new)
+				.filter(map -> !map.isEmpty());
 	}
 
 	@Override
 	default Mono<Boolean> setAndGetChanged(Map<T, U> value) {
 		return this
 				.setAndGetPrevious(value)
-				.map(oldValue -> !Objects.equals(oldValue, value))
+				.map(oldValue -> !Objects.equals(oldValue, value.isEmpty() ? null : value))
 				.switchIfEmpty(Mono.fromSupplier(() -> !value.isEmpty()));
 	}
 
@@ -286,17 +267,17 @@ public interface DatabaseStageMap<T, U, US extends DatabaseStage<U>> extends Dat
 
 	@Override
 	default Mono<Map<T, U>> get(@Nullable CompositeSnapshot snapshot, boolean existsAlmostCertainly) {
-		return getAllValues(snapshot)
+		return this
-				.collectMap(Entry::getKey, Entry::getValue, HashMap::new);
+				.getAllValues(snapshot)
+				.collectMap(Entry::getKey, Entry::getValue, HashMap::new)
+				.filter(map -> !map.isEmpty());
 	}
 
 	@Override
 	default Mono<Long> leavesCount(@Nullable CompositeSnapshot snapshot, boolean fast) {
-		return getAllStages(snapshot)
+		return this
-				.flatMap(stage -> Mono
+				.getAllStages(snapshot)
-						.fromRunnable(() -> stage.getValue().release())
+				.doOnNext(stage -> stage.getValue().close())
-						.thenReturn(true)
-				)
 				.count();
 	}
 

src/main/java/it/cavallium/dbengine/database/collections/DatabaseStageWithEntry.java

@@ -1,5 +1,6 @@
 package it.cavallium.dbengine.database.collections;
 
+import io.net5.buffer.api.Resource;
 import it.cavallium.dbengine.client.BadBlock;
 import reactor.core.publisher.Mono;
 

src/main/java/it/cavallium/dbengine/database/collections/SubStageGetterHashMap.java

@@ -4,6 +4,7 @@ import io.net5.buffer.api.Buffer;
 import io.net5.buffer.api.Send;
 import it.cavallium.dbengine.client.CompositeSnapshot;
 import it.cavallium.dbengine.database.LLDictionary;
+import it.cavallium.dbengine.database.LLUtils;
 import it.cavallium.dbengine.database.serialization.Serializer;
 import it.cavallium.dbengine.database.serialization.SerializerFixedBinaryLength;
 import java.util.Map;
@@ -34,20 +35,9 @@ public class SubStageGetterHashMap<T, U, TH> implements
 	public Mono<DatabaseMapDictionaryHashed<T, U, TH>> subStage(LLDictionary dictionary,
 			@Nullable CompositeSnapshot snapshot,
 			Mono<Send<Buffer>> prefixKeyMono) {
-		return Mono.usingWhen(
+		return LLUtils.usingSend(prefixKeyMono, prefixKey -> Mono.just(DatabaseMapDictionaryHashed
-				prefixKeyMono,
+				.tail(dictionary, prefixKey, keySerializer, valueSerializer, keyHashFunction,
-				prefixKey -> Mono
+						keyHashSerializer, d -> {})), true);
-						.fromSupplier(() -> DatabaseMapDictionaryHashed
-								.tail(dictionary,
-										prefixKey,
-										keySerializer,
-										valueSerializer,
-										keyHashFunction,
-										keyHashSerializer
-								)
-						),
-				prefixKey -> Mono.fromRunnable(prefixKey::close)
-		);
 	}
 
 	public int getKeyHashBinaryLength() {

src/main/java/it/cavallium/dbengine/database/collections/SubStageGetterHashSet.java

@@ -34,13 +34,8 @@ public class SubStageGetterHashSet<T, TH> implements
 			Mono<Send<Buffer>> prefixKeyMono) {
 		return Mono.usingWhen(prefixKeyMono,
 				prefixKey -> Mono
-						.fromSupplier(() -> DatabaseSetDictionaryHashed
+						.fromSupplier(() -> DatabaseSetDictionaryHashed.tail(dictionary, prefixKey, keySerializer,
-								.tail(dictionary,
+								keyHashFunction, keyHashSerializer, d -> {})
-										prefixKey,
-										keySerializer,
-										keyHashFunction,
-										keyHashSerializer
-								)
 						),
 				prefixKey -> Mono.fromRunnable(prefixKey::close)
 		);

src/main/java/it/cavallium/dbengine/database/collections/SubStageGetterMap.java

@@ -4,6 +4,7 @@ import io.net5.buffer.api.Buffer;
 import io.net5.buffer.api.Send;
 import it.cavallium.dbengine.client.CompositeSnapshot;
 import it.cavallium.dbengine.database.LLDictionary;
+import it.cavallium.dbengine.database.LLUtils;
 import it.cavallium.dbengine.database.serialization.Serializer;
 import it.cavallium.dbengine.database.serialization.SerializerFixedBinaryLength;
 import java.util.Map;
@@ -25,11 +26,9 @@ public class SubStageGetterMap<T, U> implements SubStageGetter<Map<T, U>, Databa
 	public Mono<DatabaseMapDictionary<T, U>> subStage(LLDictionary dictionary,
 			@Nullable CompositeSnapshot snapshot,
 			Mono<Send<Buffer>> prefixKeyMono) {
-		return Mono.usingWhen(prefixKeyMono,
+		return LLUtils.usingSend(prefixKeyMono,
 				prefixKey -> Mono.fromSupplier(() -> DatabaseMapDictionary
-						.tail(dictionary, prefixKey, keySerializer, valueSerializer)),
+						.tail(dictionary, prefixKey, keySerializer, valueSerializer, d -> {})), true);
-				prefixKey -> Mono.fromRunnable(prefixKey::close)
-		);
 	}
 
 	public int getKeyBinaryLength() {

src/main/java/it/cavallium/dbengine/database/collections/SubStageGetterMapDeep.java

@@ -4,6 +4,7 @@ import io.net5.buffer.api.Buffer;
 import io.net5.buffer.api.Send;
 import it.cavallium.dbengine.client.CompositeSnapshot;
 import it.cavallium.dbengine.database.LLDictionary;
+import it.cavallium.dbengine.database.LLUtils;
 import it.cavallium.dbengine.database.serialization.SerializerFixedBinaryLength;
 import java.util.Map;
 import org.jetbrains.annotations.Nullable;
@@ -40,11 +41,9 @@ public class SubStageGetterMapDeep<T, U, US extends DatabaseStage<U>> implements
 	public Mono<DatabaseMapDictionaryDeep<T, U, US>> subStage(LLDictionary dictionary,
 			@Nullable CompositeSnapshot snapshot,
 			Mono<Send<Buffer>> prefixKeyMono) {
-		return Mono.usingWhen(prefixKeyMono,
+		return LLUtils.usingSend(prefixKeyMono, prefixKey -> Mono.just(DatabaseMapDictionaryDeep
-				prefixKey -> Mono.fromSupplier(() -> DatabaseMapDictionaryDeep
+				.deepIntermediate(dictionary, prefixKey, keySerializer, subStageGetter, keyExtLength,
-						.deepIntermediate(dictionary, prefixKey, keySerializer, subStageGetter, keyExtLength)),
+						d -> {})), true);
-				prefixKey -> Mono.fromRunnable(prefixKey::close)
-		);
 	}
 
 	public int getKeyBinaryLength() {

src/main/java/it/cavallium/dbengine/database/collections/SubStageGetterSet.java

@@ -24,7 +24,7 @@ public class SubStageGetterSet<T> implements SubStageGetter<Map<T, Nothing>, Dat
 			Mono<Send<Buffer>> prefixKeyMono) {
 		return Mono.usingWhen(prefixKeyMono,
 				prefixKey -> Mono
-						.fromSupplier(() -> DatabaseSetDictionary.tail(dictionary, prefixKey, keySerializer)),
+						.fromSupplier(() -> DatabaseSetDictionary.tail(dictionary, prefixKey, keySerializer, d -> {})),
 				prefixKey -> Mono.fromRunnable(prefixKey::close)
 		);
 	}

src/main/java/it/cavallium/dbengine/database/collections/SubStageGetterSingle.java

@@ -20,12 +20,7 @@ public class SubStageGetterSingle<T> implements SubStageGetter<T, DatabaseStageE
 	public Mono<DatabaseStageEntry<T>> subStage(LLDictionary dictionary,
 			@Nullable CompositeSnapshot snapshot,
 			Mono<Send<Buffer>> keyPrefixMono) {
-		return Mono.usingWhen(
+		return keyPrefixMono.map(keyPrefix -> new DatabaseSingle<>(dictionary, keyPrefix, serializer, d -> {}));
-				keyPrefixMono,
-				keyPrefix -> Mono
-						.<DatabaseStageEntry<T>>fromSupplier(() -> new DatabaseSingle<>(dictionary, keyPrefix, serializer)),
-				keyPrefix -> Mono.fromRunnable(keyPrefix::close)
-		);
 	}
 
 }

src/main/java/it/cavallium/dbengine/database/collections/ValueWithHashSerializer.java

@@ -2,13 +2,16 @@ package it.cavallium.dbengine.database.collections;
 
 import io.net5.buffer.api.Buffer;
 import io.net5.buffer.api.BufferAllocator;
+import io.net5.buffer.api.CompositeBuffer;
 import io.net5.buffer.api.Send;
 import it.cavallium.dbengine.database.LLUtils;
 import it.cavallium.dbengine.database.serialization.SerializationException;
 import it.cavallium.dbengine.database.serialization.Serializer;
 import java.util.Map;
 import java.util.Map.Entry;
+import java.util.Objects;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
 class ValueWithHashSerializer<X, Y> implements Serializer<Entry<X, Y>> {
 
@@ -25,8 +28,9 @@ class ValueWithHashSerializer<X, Y> implements Serializer<Entry<X, Y>> {
 	}
 
 	@Override
-	public @NotNull DeserializationResult<Entry<X, Y>> deserialize(@NotNull Send<Buffer> serializedToReceive)
+	public @NotNull DeserializationResult<Entry<X, Y>> deserialize(@Nullable Send<Buffer> serializedToReceive)
 			throws SerializationException {
+		Objects.requireNonNull(serializedToReceive);
 		try (var serialized = serializedToReceive.receive()) {
 			DeserializationResult<X> deserializedKey = keySuffixSerializer.deserialize(serialized.copy().send());
 			DeserializationResult<Y> deserializedValue = valueSerializer.deserialize(serialized
@@ -41,10 +45,8 @@ class ValueWithHashSerializer<X, Y> implements Serializer<Entry<X, Y>> {
 
 	@Override
 	public @NotNull Send<Buffer> serialize(@NotNull Entry<X, Y> deserialized) throws SerializationException {
-		try (Buffer keySuffix = keySuffixSerializer.serialize(deserialized.getKey()).receive()) {
+		var keySuffix = keySuffixSerializer.serialize(deserialized.getKey());
-			try (Buffer value = valueSerializer.serialize(deserialized.getValue()).receive()) {
+		var value = valueSerializer.serialize(deserialized.getValue());
-				return LLUtils.compositeBuffer(allocator, keySuffix.send(), value.send());
+		return LLUtils.compositeBuffer(allocator, keySuffix, value).send();
-			}
-		}
 	}
 }

src/main/java/it/cavallium/dbengine/database/collections/ValuesSetSerializer.java

@@ -7,7 +7,9 @@ import it.cavallium.dbengine.database.serialization.SerializationException;
 import it.cavallium.dbengine.database.serialization.Serializer;
 import it.unimi.dsi.fastutil.objects.ObjectArraySet;
 import java.util.ArrayList;
+import java.util.Objects;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
 class ValuesSetSerializer<X> implements Serializer<ObjectArraySet<X>> {
 
@@ -20,7 +22,8 @@ class ValuesSetSerializer<X> implements Serializer<ObjectArraySet<X>> {
 	}
 
 	@Override
-	public @NotNull DeserializationResult<ObjectArraySet<X>> deserialize(@NotNull Send<Buffer> serializedToReceive) throws SerializationException {
+	public @NotNull DeserializationResult<ObjectArraySet<X>> deserialize(@Nullable Send<Buffer> serializedToReceive) throws SerializationException {
+		Objects.requireNonNull(serializedToReceive);
 		try (var serialized = serializedToReceive.receive()) {
 			int initialReaderOffset = serialized.readerOffset();
 			int entriesLength = serialized.readInt();
@@ -41,11 +44,14 @@ class ValuesSetSerializer<X> implements Serializer<ObjectArraySet<X>> {
 		try (Buffer output = allocator.allocate(64)) {
 			output.writeInt(deserialized.size());
 			for (X entry : deserialized) {
-				try (Buffer serialized = entrySerializer.serialize(entry).receive()) {
+				var serializedToReceive = entrySerializer.serialize(entry);
+				try (Buffer serialized = serializedToReceive.receive()) {
+					if (serialized.readableBytes() > 0) {
 						output.ensureWritable(serialized.readableBytes());
 						output.writeBytes(serialized);
 					}
 				}
+			}
 			return output.send();
 		}
 	}

src/main/java/it/cavallium/dbengine/database/disk/CachedIndexSearcher.java

@@ -1,106 +0,0 @@
-package it.cavallium.dbengine.database.disk;
-
-import java.io.IOException;
-import org.apache.lucene.index.IndexReader;
-import org.apache.lucene.search.IndexSearcher;
-import org.apache.lucene.search.SearcherManager;
-import org.jetbrains.annotations.Nullable;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
-
-public class CachedIndexSearcher {
-
-	private static final Logger logger = LoggerFactory.getLogger(CachedIndexSearcher.class);
-
-	private final IndexSearcher indexSearcher;
-	private final SearcherManager associatedSearcherManager;
-	private final Runnable afterFinalization;
-	private boolean inCache = true;
-	private int usages = 0;
-
-	public CachedIndexSearcher(IndexSearcher indexSearcher,
-			@Nullable SearcherManager associatedSearcherManager,
-			@Nullable Runnable afterFinalization) {
-		this.indexSearcher = indexSearcher;
-		this.associatedSearcherManager = associatedSearcherManager;
-		this.afterFinalization = afterFinalization;
-	}
-
-	public void incUsage() {
-		synchronized (this) {
-			usages++;
-		}
-	}
-
-	public void decUsage() throws IOException {
-		synchronized (this) {
-			if (usages > 0) {
-				usages--;
-				if (mustClose()) {
-					try {
-						close();
-					} finally {
-						if (afterFinalization != null) afterFinalization.run();
-					}
-				}
-			}
-		}
-	}
-
-	public void removeFromCache() throws IOException {
-		synchronized (this) {
-			if (inCache) {
-				inCache = false;
-				if (mustClose()) {
-					try {
-						close();
-					} finally {
-						if (afterFinalization != null) afterFinalization.run();
-					}
-				}
-			}
-		}
-	}
-
-	private void close() throws IOException {
-		if (associatedSearcherManager != null) {
-			associatedSearcherManager.release(indexSearcher);
-		}
-	}
-
-	private boolean mustClose() {
-		return !this.inCache && this.usages == 0;
-	}
-
-	public IndexReader getIndexReader() {
-		return indexSearcher.getIndexReader();
-	}
-
-	public IndexSearcher getIndexSearcher() {
-		return indexSearcher;
-	}
-
-	@SuppressWarnings("deprecation")
-	@Override
-	protected void finalize() throws Throwable {
-		boolean failedToRelease = false;
-		if (usages > 0) {
-			failedToRelease = true;
-			logger.error("A cached index searcher has been garbage collected, but "
-					+ usages + " usages have not been released");
-		}
-		if (inCache) {
-			failedToRelease = true;
-			logger.error("A cached index searcher has been garbage collected, but it's marked"
-					+ " as still actively cached");
-		}
-		if (failedToRelease) {
-			try {
-				this.close();
-			} catch (Throwable ex) {
-				logger.warn("Error when closing cached index searcher", ex);
-			}
-		}
-		super.finalize();
-	}
-}

src/main/java/it/cavallium/dbengine/database/disk/CachedIndexSearcherManager.java

@@ -3,16 +3,16 @@ package it.cavallium.dbengine.database.disk;
 import com.google.common.cache.CacheBuilder;
 import com.google.common.cache.CacheLoader;
 import com.google.common.cache.LoadingCache;
+import io.net5.buffer.api.Send;
+import io.net5.buffer.api.internal.ResourceSupport;
 import it.cavallium.dbengine.database.LLSnapshot;
 import java.io.IOException;
+import java.io.UncheckedIOException;
 import java.time.Duration;
-import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.Phaser;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.TimeoutException;
-import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.concurrent.atomic.AtomicInteger;
-import java.util.concurrent.locks.LockSupport;
 import java.util.function.Function;
 import org.apache.lucene.index.IndexWriter;
 import org.apache.lucene.search.IndexSearcher;
@@ -29,8 +29,9 @@ import reactor.core.publisher.Mono;
 import reactor.core.publisher.Sinks;
 import reactor.core.publisher.Sinks.Empty;
 import reactor.core.scheduler.Schedulers;
+import reactor.util.function.Tuples;
 
-public class CachedIndexSearcherManager {
+public class CachedIndexSearcherManager implements IndexSearcherManager {
 
 	private static final Logger logger = LoggerFactory.getLogger(CachedIndexSearcherManager.class);
 
@@ -41,8 +42,8 @@ public class CachedIndexSearcherManager {
 	private final Phaser activeSearchers = new Phaser(1);
 	private final Phaser activeRefreshes = new Phaser(1);
 
-	private final LoadingCache<LLSnapshot, Mono<CachedIndexSearcher>> cachedSnapshotSearchers;
+	private final LoadingCache<LLSnapshot, Mono<Send<LLIndexSearcher>>> cachedSnapshotSearchers;
-	private final Mono<CachedIndexSearcher> cachedMainSearcher;
+	private final Mono<Send<LLIndexSearcher>> cachedMainSearcher;
 
 	private final Empty<Void> closeRequested = Sinks.empty();
 	private final Empty<Void> refresherClosed = Sinks.empty();
@@ -84,7 +85,7 @@ public class CachedIndexSearcherManager {
 				.maximumSize(3)
 				.build(new CacheLoader<>() {
 					@Override
-					public Mono<CachedIndexSearcher> load(@NotNull LLSnapshot snapshot) {
+					public Mono<Send<LLIndexSearcher>> load(@NotNull LLSnapshot snapshot) {
 						return CachedIndexSearcherManager.this.generateCachedSearcher(snapshot);
 					}
 				});
@@ -129,47 +130,39 @@ public class CachedIndexSearcherManager {
 				})).cache();
 	}
 
-	private Mono<CachedIndexSearcher> generateCachedSearcher(@Nullable LLSnapshot snapshot) {
+	private Mono<Send<LLIndexSearcher>> generateCachedSearcher(@Nullable LLSnapshot snapshot) {
+		// todo: check if defer is really needed
+		return Mono.defer(() -> {
+			var onClose = this.closeRequested.asMono();
+			var onQueryRefresh = Mono.delay(queryRefreshDebounceTime).then();
+			var onInvalidateCache = Mono.firstWithSignal(onClose, onQueryRefresh).doOnNext(s -> System.err.println("Invalidation triggered"));
+
 			return Mono.fromCallable(() -> {
 						activeSearchers.register();
 						IndexSearcher indexSearcher;
-					SearcherManager associatedSearcherManager;
 						if (snapshot == null) {
 							indexSearcher = searcherManager.acquire();
-						indexSearcher.setSimilarity(similarity);
-						associatedSearcherManager = searcherManager;
 						} else {
 							indexSearcher = snapshotsManager.resolveSnapshot(snapshot).getIndexSearcher();
-						associatedSearcherManager = null;
 						}
-					AtomicBoolean alreadyDeregistered = new AtomicBoolean(false);
+						indexSearcher.setSimilarity(similarity);
-					return new CachedIndexSearcher(indexSearcher, associatedSearcherManager,
+						assert indexSearcher.getIndexReader().getRefCount() > 0;
-							() -> {
+						return indexSearcher;
-								// This shouldn't happen more than once,
-								// but I put this AtomicBoolean to be sure that this will NEVER happen more than once.
-								if (alreadyDeregistered.compareAndSet(false, true)) {
-									activeSearchers.arriveAndDeregister();
-								} else {
-									logger.error("Disposed CachedIndexSearcher twice! This is an implementation bug!");
-								}
-							}
-					);
 					})
-				.cacheInvalidateWhen(indexSearcher -> Mono
+					// todo: re-enable caching if needed
-								.firstWithSignal(
+					//.cacheInvalidateWhen(tuple -> onInvalidateCache)
-										this.closeRequested.asMono(),
+					.map(indexSearcher -> new LLIndexSearcher(indexSearcher, this::dropCachedIndexSearcher).send())
-										Mono.delay(queryRefreshDebounceTime).then()
+					.takeUntilOther(onClose)
-								),
+					.doOnDiscard(Send.class, Send::close);
-						indexSearcher -> {
-							try {
-								// Mark as removed from cache
-								indexSearcher.removeFromCache();
-							} catch (Exception ex) {
-								logger.error("Failed to release an old cached IndexSearcher", ex);
-							}
 		});
 	}
 
+	private void dropCachedIndexSearcher(LLIndexSearcher cachedIndexSearcher) {
+		// This shouldn't happen more than once per searcher.
+		activeSearchers.arriveAndDeregister();
+	}
+
+	@Override
 	public void maybeRefreshBlocking() throws IOException {
 		try {
 			activeRefreshes.register();
@@ -181,6 +174,7 @@ public class CachedIndexSearcherManager {
 		}
 	}
 
+	@Override
 	public void maybeRefresh() throws IOException {
 		try {
 			activeRefreshes.register();
@@ -192,30 +186,8 @@ public class CachedIndexSearcherManager {
 		}
 	}
 
-	public <T> Flux<T> searchMany(@Nullable LLSnapshot snapshot, Function<IndexSearcher, Flux<T>> searcherFunction) {
+	@Override
-		return Flux.usingWhen(
+	public Mono<Send<LLIndexSearcher>> retrieveSearcher(@Nullable LLSnapshot snapshot) {
-				this.captureIndexSearcher(snapshot),
-				indexSearcher -> searcherFunction.apply(indexSearcher.getIndexSearcher()),
-				this::releaseUsedIndexSearcher
-		);
-	}
-
-	public <T> Mono<T> search(@Nullable LLSnapshot snapshot, Function<IndexSearcher, Mono<T>> searcherFunction) {
-		return Mono.usingWhen(
-				this.captureIndexSearcher(snapshot),
-				indexSearcher -> searcherFunction.apply(indexSearcher.getIndexSearcher()),
-				this::releaseUsedIndexSearcher
-		);
-	}
-
-	public Mono<CachedIndexSearcher> captureIndexSearcher(@Nullable LLSnapshot snapshot) {
-		return this
-				.retrieveCachedIndexSearcher(snapshot)
-				// Increment reference count
-				.doOnNext(CachedIndexSearcher::incUsage);
-	}
-
-	private Mono<CachedIndexSearcher> retrieveCachedIndexSearcher(LLSnapshot snapshot) {
 		if (snapshot == null) {
 			return this.cachedMainSearcher;
 		} else {
@@ -223,17 +195,7 @@ public class CachedIndexSearcherManager {
 		}
 	}
 
-	public Mono<Void> releaseUsedIndexSearcher(CachedIndexSearcher indexSearcher) {
+	@Override
-		return Mono.fromRunnable(() -> {
-			try {
-				// Decrement reference count
-				indexSearcher.decUsage();
-			} catch (Exception ex) {
-				logger.error("Failed to release an used IndexSearcher", ex);
-			}
-		});
-	}
-
 	public Mono<Void> close() {
 		return closeMono;
 	}

src/main/java/it/cavallium/dbengine/database/disk/IndexSearcherManager.java

@@ -0,0 +1,21 @@
+package it.cavallium.dbengine.database.disk;
+
+import io.net5.buffer.api.Send;
+import it.cavallium.dbengine.database.LLSnapshot;
+import java.io.IOException;
+import java.util.function.Function;
+import org.apache.lucene.search.IndexSearcher;
+import org.jetbrains.annotations.Nullable;
+import reactor.core.publisher.Flux;
+import reactor.core.publisher.Mono;
+
+public interface IndexSearcherManager {
+
+	void maybeRefreshBlocking() throws IOException;
+
+	void maybeRefresh() throws IOException;
+
+	Mono<Send<LLIndexSearcher>> retrieveSearcher(@Nullable LLSnapshot snapshot);
+
+	Mono<Void> close();
+}

src/main/java/it/cavallium/dbengine/database/disk/LLIndexSearcher.java

@@ -0,0 +1,52 @@
+package it.cavallium.dbengine.database.disk;
+
+import io.net5.buffer.api.Drop;
+import io.net5.buffer.api.Owned;
+import io.net5.buffer.api.internal.ResourceSupport;
+import it.cavallium.dbengine.database.LiveResourceSupport;
+import java.io.IOException;
+import org.apache.lucene.index.IndexReader;
+import org.apache.lucene.search.IndexSearcher;
+import org.apache.lucene.search.SearcherManager;
+import org.jetbrains.annotations.Nullable;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+public class LLIndexSearcher extends LiveResourceSupport<LLIndexSearcher, LLIndexSearcher> {
+
+	private IndexSearcher indexSearcher;
+
+	public LLIndexSearcher(IndexSearcher indexSearcher, Drop<LLIndexSearcher> drop) {
+		super(drop);
+		this.indexSearcher = indexSearcher;
+	}
+
+	public IndexReader getIndexReader() {
+		if (!isOwned()) {
+			throw attachTrace(new IllegalStateException("LLIndexSearcher must be owned to be used"));
+		}
+		return indexSearcher.getIndexReader();
+	}
+
+	public IndexSearcher getIndexSearcher() {
+		if (!isOwned()) {
+			throw attachTrace(new IllegalStateException("LLIndexSearcher must be owned to be used"));
+		}
+		return indexSearcher;
+	}
+
+	@Override
+	protected RuntimeException createResourceClosedException() {
+		return new IllegalStateException("Closed");
+	}
+
+	@Override
+	protected Owned<LLIndexSearcher> prepareSend() {
+		var indexSearcher = this.indexSearcher;
+		return drop -> new LLIndexSearcher(indexSearcher, drop);
+	}
+
+	protected void makeInaccessible() {
+		this.indexSearcher = null;
+	}
+}

src/main/java/it/cavallium/dbengine/database/disk/LLIndexSearchers.java

@@ -0,0 +1,207 @@
+package it.cavallium.dbengine.database.disk;
+
+import io.net5.buffer.api.Drop;
+import io.net5.buffer.api.Owned;
+import io.net5.buffer.api.Resource;
+import io.net5.buffer.api.Send;
+import io.net5.buffer.api.internal.ResourceSupport;
+import it.cavallium.dbengine.database.LiveResourceSupport;
+import it.unimi.dsi.fastutil.objects.Object2IntOpenHashMap;
+import java.io.IOException;
+import java.io.UncheckedIOException;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.Comparator;
+import java.util.HashMap;
+import java.util.List;
+import org.apache.lucene.index.Fields;
+import org.apache.lucene.index.IndexReader;
+import org.apache.lucene.index.IndexReaderContext;
+import org.apache.lucene.index.MultiReader;
+import org.apache.lucene.index.StoredFieldVisitor;
+import org.apache.lucene.index.Term;
+import org.apache.lucene.search.IndexSearcher;
+
+public interface LLIndexSearchers extends Resource<LLIndexSearchers> {
+
+	static LLIndexSearchers of(List<Send<LLIndexSearcher>> indexSearchers) {
+		return new ShardedIndexSearchers(indexSearchers, d -> {});
+	}
+
+	static UnshardedIndexSearchers unsharded(Send<LLIndexSearcher> indexSearcher) {
+		return new UnshardedIndexSearchers(indexSearcher, d -> {});
+	}
+
+	List<IndexSearcher> shards();
+
+	IndexSearcher shard(int shardIndex);
+
+	IndexReader allShards();
+
+	class UnshardedIndexSearchers extends LiveResourceSupport<LLIndexSearchers, UnshardedIndexSearchers>
+			implements LLIndexSearchers {
+
+		private LLIndexSearcher indexSearcher;
+
+		public UnshardedIndexSearchers(Send<LLIndexSearcher> indexSearcher, Drop<UnshardedIndexSearchers> drop) {
+			super(new CloseOnDrop(drop));
+			this.indexSearcher = indexSearcher.receive();
+		}
+
+		@Override
+		public List<IndexSearcher> shards() {
+			return List.of(indexSearcher.getIndexSearcher());
+		}
+
+		@Override
+		public IndexSearcher shard(int shardIndex) {
+			if (!isOwned()) {
+				throw attachTrace(new IllegalStateException("UnshardedIndexSearchers must be owned to be used"));
+			}
+			if (shardIndex != -1) {
+				throw new IndexOutOfBoundsException("Shard index " + shardIndex + " is invalid, this is a unsharded index");
+			}
+			return indexSearcher.getIndexSearcher();
+		}
+
+		@Override
+		public IndexReader allShards() {
+			return indexSearcher.getIndexReader();
+		}
+
+		public IndexSearcher shard() {
+			return this.shard(-1);
+		}
+
+		@Override
+		protected RuntimeException createResourceClosedException() {
+			return new IllegalStateException("Closed");
+		}
+
+		@Override
+		protected Owned<UnshardedIndexSearchers> prepareSend() {
+			Send<LLIndexSearcher> indexSearcher = this.indexSearcher.send();
+			return drop -> new UnshardedIndexSearchers(indexSearcher, drop);
+		}
+
+		protected void makeInaccessible() {
+			this.indexSearcher = null;
+		}
+
+		private static class CloseOnDrop implements Drop<UnshardedIndexSearchers> {
+
+			private final Drop<UnshardedIndexSearchers> delegate;
+
+			public CloseOnDrop(Drop<UnshardedIndexSearchers> drop) {
+				this.delegate = drop;
+			}
+
+			@Override
+			public void drop(UnshardedIndexSearchers obj) {
+				if (obj.indexSearcher != null) obj.indexSearcher.close();
+				delegate.drop(obj);
+			}
+		}
+	}
+
+	class ShardedIndexSearchers extends LiveResourceSupport<LLIndexSearchers, ShardedIndexSearchers>
+			implements LLIndexSearchers {
+
+		private List<LLIndexSearcher> indexSearchers;
+		private List<IndexSearcher> indexSearchersVals;
+
+		public ShardedIndexSearchers(List<Send<LLIndexSearcher>> indexSearchers, Drop<ShardedIndexSearchers> drop) {
+			super(new CloseOnDrop(drop));
+			this.indexSearchers = new ArrayList<>(indexSearchers.size());
+			this.indexSearchersVals = new ArrayList<>(indexSearchers.size());
+			for (Send<LLIndexSearcher> llIndexSearcher : indexSearchers) {
+				var indexSearcher = llIndexSearcher.receive();
+				this.indexSearchers.add(indexSearcher);
+				this.indexSearchersVals.add(indexSearcher.getIndexSearcher());
+			}
+		}
+
+		@Override
+		public List<IndexSearcher> shards() {
+			if (!isOwned()) {
+				throw attachTrace(new IllegalStateException("ShardedIndexSearchers must be owned to be used"));
+			}
+			return Collections.unmodifiableList(indexSearchersVals);
+		}
+
+		@Override
+		public IndexSearcher shard(int shardIndex) {
+			if (!isOwned()) {
+				throw attachTrace(new IllegalStateException("ShardedIndexSearchers must be owned to be used"));
+			}
+			if (shardIndex < 0) {
+				throw new IndexOutOfBoundsException("Shard index " + shardIndex + " is invalid");
+			}
+			return indexSearchersVals.get(shardIndex);
+		}
+
+		@Override
+		public IndexReader allShards() {
+			if (!isOwned()) {
+				throw attachTrace(new IllegalStateException("ShardedIndexSearchers must be owned to be used"));
+			}
+			var irs = new IndexReader[indexSearchersVals.size()];
+			for (int i = 0, s = indexSearchersVals.size(); i < s; i++) {
+				irs[i] = indexSearchersVals.get(i).getIndexReader();
+			}
+			Object2IntOpenHashMap<IndexReader> indexes = new Object2IntOpenHashMap<>();
+			for (int i = 0; i < irs.length; i++) {
+				indexes.put(irs[i], i);
+			}
+			try {
+				return new MultiReader(irs, Comparator.comparingInt(indexes::getInt), false);
+			} catch (IOException ex) {
+				// This shouldn't happen
+				throw new UncheckedIOException(ex);
+			}
+		}
+
+		@Override
+		protected RuntimeException createResourceClosedException() {
+			return new IllegalStateException("Closed");
+		}
+
+		@Override
+		protected Owned<ShardedIndexSearchers> prepareSend() {
+			List<Send<LLIndexSearcher>> indexSearchers = new ArrayList<>(this.indexSearchers.size());
+			for (LLIndexSearcher indexSearcher : this.indexSearchers) {
+				indexSearchers.add(indexSearcher.send());
+			}
+			return drop -> new ShardedIndexSearchers(indexSearchers, drop);
+		}
+
+		protected void makeInaccessible() {
+			this.indexSearchers = null;
+			this.indexSearchersVals = null;
+		}
+
+		private static class CloseOnDrop implements Drop<ShardedIndexSearchers> {
+
+			private volatile boolean dropped = false;
+			private final Drop<ShardedIndexSearchers> delegate;
+
+			public CloseOnDrop(Drop<ShardedIndexSearchers> drop) {
+				this.delegate = drop;
+			}
+
+			@Override
+			public void drop(ShardedIndexSearchers obj) {
+				assert !dropped;
+				if (obj.indexSearchers != null) {
+					for (LLIndexSearcher indexSearcher : obj.indexSearchers) {
+						if (indexSearcher.isAccessible()) {
+							indexSearcher.close();
+						}
+					}
+				}
+				dropped = true;
+				delegate.drop(obj);
+			}
+		}
+	}
+}

src/main/java/it/cavallium/dbengine/database/disk/LLLocalDictionary.java

@@ -267,10 +267,23 @@ public class LLLocalDictionary implements LLDictionary {
 								stamp = 0;
 							}
 							try {
+								Buffer logKey;
 								if (logger.isTraceEnabled(MARKER_ROCKSDB)) {
-									logger.trace(MARKER_ROCKSDB, "Reading {}", LLUtils.toStringSafe(key));
+									logKey = key.copy();
+								} else {
+									logKey = null;
+								}
+								try (logKey) {
+									var result = dbGet(cfh, resolveSnapshot(snapshot), key.send(), existsAlmostCertainly);
+									if (logger.isTraceEnabled(MARKER_ROCKSDB)) {
+										try (var result2 = result == null ? null : result.receive()) {
+											logger.trace(MARKER_ROCKSDB, "Reading {}: {}", LLUtils.toStringSafe(logKey), LLUtils.toString(result2));
+											return result2 == null ? null : result2.send();
+										}
+									} else {
+										return result;
+									}
 								}
-								return dbGet(cfh, resolveSnapshot(snapshot), key.send(), existsAlmostCertainly);
 							} finally {
 								if (updateMode == UpdateMode.ALLOW) {
 									lock.unlockRead(stamp);
@@ -300,7 +313,7 @@ public class LLLocalDictionary implements LLDictionary {
 				// Unfortunately it's not feasible until RocksDB implements keyMayExist with buffers
 
 				// Create the key nio buffer to pass to RocksDB
-				var keyNioBuffer = LLUtils.convertToDirect(alloc, key.send());
+				var keyNioBuffer = LLUtils.convertToReadableDirect(alloc, key.send());
 				// Create a direct result buffer because RocksDB works only with direct buffers
 				try (Buffer resultBuf = alloc.allocate(INITIAL_DIRECT_READ_BYTE_BUF_SIZE_BYTES)) {
 					int valueSize;
@@ -308,7 +321,7 @@ public class LLLocalDictionary implements LLDictionary {
 					ByteBuffer resultNioBuf;
 					do {
 						// Create the result nio buffer to pass to RocksDB
-						resultNioBuf = LLUtils.obtainDirect(resultBuf);
+						resultNioBuf = LLUtils.obtainDirect(resultBuf, true);
 						assert keyNioBuffer.byteBuffer().isDirect();
 						assert resultNioBuf.isDirect();
 						valueSize = db.get(cfh,
@@ -414,11 +427,13 @@ public class LLLocalDictionary implements LLDictionary {
 					if (Schedulers.isInNonBlockingThread()) {
 						throw new UnsupportedOperationException("Called dbPut in a nonblocking thread");
 					}
+					assert key.isAccessible();
+					assert value.isAccessible();
 					if (databaseOptions.allowNettyDirect()) {
-						var keyNioBuffer = LLUtils.convertToDirect(alloc, key.send());
+						var keyNioBuffer = LLUtils.convertToReadableDirect(alloc, key.send());
 						try (var ignored1 = keyNioBuffer.buffer().receive()) {
 							assert keyNioBuffer.byteBuffer().isDirect();
-							var valueNioBuffer = LLUtils.convertToDirect(alloc, value.send());
+							var valueNioBuffer = LLUtils.convertToReadableDirect(alloc, value.send());
 							try (var ignored2 = valueNioBuffer.buffer().receive()) {
 								assert valueNioBuffer.byteBuffer().isDirect();
 								db.put(cfh, validWriteOptions, keyNioBuffer.byteBuffer(), valueNioBuffer.byteBuffer());
@@ -479,7 +494,7 @@ public class LLLocalDictionary implements LLDictionary {
 								if (range.hasMin()) {
 									try (var rangeMin = range.getMin().receive()) {
 										if (databaseOptions.allowNettyDirect()) {
-											var directBuf = LLUtils.convertToDirect(alloc, rangeMin.send());
+											var directBuf = LLUtils.convertToReadableDirect(alloc, rangeMin.send());
 											cloned1 = directBuf.buffer().receive();
 											direct1 = directBuf.byteBuffer();
 											readOpts.setIterateLowerBound(slice1 = new DirectSlice(directBuf.byteBuffer()));
@@ -491,7 +506,7 @@ public class LLLocalDictionary implements LLDictionary {
 								if (range.hasMax()) {
 									try (var rangeMax = range.getMax().receive()) {
 										if (databaseOptions.allowNettyDirect()) {
-											var directBuf = LLUtils.convertToDirect(alloc, rangeMax.send());
+											var directBuf = LLUtils.convertToReadableDirect(alloc, rangeMax.send());
 											cloned2 = directBuf.buffer().receive();
 											direct2 = directBuf.byteBuffer();
 											readOpts.setIterateUpperBound(slice2 = new DirectSlice(directBuf.byteBuffer()));
@@ -504,7 +519,7 @@ public class LLLocalDictionary implements LLDictionary {
 									if (!LLLocalDictionary.PREFER_SEEK_TO_FIRST && range.hasMin()) {
 										try (var rangeMin = range.getMin().receive()) {
 											if (databaseOptions.allowNettyDirect()) {
-												var directBuf = LLUtils.convertToDirect(alloc, rangeMin.send());
+												var directBuf = LLUtils.convertToReadableDirect(alloc, rangeMin.send());
 												cloned3 = directBuf.buffer().receive();
 												direct3 = directBuf.byteBuffer();
 												rocksIterator.seek(directBuf.byteBuffer());
@@ -592,6 +607,8 @@ public class LLLocalDictionary implements LLDictionary {
 								valueSend -> this.<Send<Buffer>>runOnDb(() -> {
 									try (var key = keySend.receive()) {
 										try (var value = valueSend.receive()) {
+											assert key.isAccessible();
+											assert value.isAccessible();
 											StampedLock lock;
 											long stamp;
 											if (updateMode == UpdateMode.ALLOW) {
@@ -656,9 +673,6 @@ public class LLLocalDictionary implements LLDictionary {
 							stamp = 0;
 						}
 						try {
-							if (logger.isTraceEnabled()) {
-								logger.trace(MARKER_ROCKSDB, "Reading {}", LLUtils.toStringSafe(key));
-							}
 							while (true) {
 								@Nullable Buffer prevData;
 								var prevDataHolder = existsAlmostCertainly ? null : new Holder<byte[]>();
@@ -682,11 +696,19 @@ public class LLLocalDictionary implements LLDictionary {
 								} else {
 									prevData = null;
 								}
+								if (logger.isTraceEnabled()) {
+									logger.trace(MARKER_ROCKSDB,
+											"Reading {}: {} (before update)",
+											LLUtils.toStringSafe(key),
+											LLUtils.toStringSafe(prevData)
+									);
+								}
 								try {
 									@Nullable Buffer newData;
 									try (Buffer prevDataToSendToUpdater = prevData == null ? null : prevData.copy()) {
-										try (var newDataToReceive = updater.apply(
+										try (var sentData = prevDataToSendToUpdater == null ? null
-												prevDataToSendToUpdater == null ? null : prevDataToSendToUpdater.send())) {
+												: prevDataToSendToUpdater.send()) {
+											try (var newDataToReceive = updater.apply(sentData)) {
 												if (newDataToReceive != null) {
 													newData = newDataToReceive.receive();
 												} else {
@@ -694,7 +716,17 @@ public class LLLocalDictionary implements LLDictionary {
 												}
 											}
 										}
+									}
+									assert newData == null || newData.isAccessible();
 									try {
+										if (logger.isTraceEnabled()) {
+											logger.trace(MARKER_ROCKSDB,
+													"Updating {}. previous data: {}, updated data: {}",
+													LLUtils.toStringSafe(key),
+													LLUtils.toStringSafe(prevData),
+													LLUtils.toStringSafe(newData)
+											);
+										}
 										if (prevData != null && newData == null) {
 											//noinspection DuplicatedCode
 											if (updateMode == UpdateMode.ALLOW) {
@@ -709,7 +741,7 @@ public class LLLocalDictionary implements LLDictionary {
 												}
 											}
 											if (logger.isTraceEnabled()) {
-												logger.trace(MARKER_ROCKSDB, "Deleting {}", LLUtils.toStringSafe(key));
+												logger.trace(MARKER_ROCKSDB, "Deleting {} (after update)", LLUtils.toStringSafe(key));
 											}
 											dbDelete(cfh, null, key.send());
 										} else if (newData != null
@@ -727,7 +759,11 @@ public class LLLocalDictionary implements LLDictionary {
 												}
 											}
 											if (logger.isTraceEnabled()) {
-												logger.trace(MARKER_ROCKSDB, "Writing {}: {}", LLUtils.toStringSafe(key), LLUtils.toStringSafe(newData));
+												logger.trace(MARKER_ROCKSDB,
+														"Writing {}: {} (after update)",
+														LLUtils.toStringSafe(key),
+														LLUtils.toStringSafe(newData)
+												);
 											}
 											Buffer dataToPut;
 											if (updateReturnMode == UpdateReturnMode.GET_NEW_VALUE) {
@@ -779,7 +815,7 @@ public class LLLocalDictionary implements LLDictionary {
 			SerializationFunction<@Nullable Send<Buffer>, @Nullable Send<Buffer>> updater,
 			boolean existsAlmostCertainly) {
 		return Mono.usingWhen(keyMono,
-				keySend -> this.runOnDb(() -> {
+				keySend -> runOnDb(() -> {
 					try (var key = keySend.receive()) {
 						if (Schedulers.isInNonBlockingThread()) {
 							throw new UnsupportedOperationException("Called update in a nonblocking thread");
@@ -798,9 +834,6 @@ public class LLLocalDictionary implements LLDictionary {
 							stamp = 0;
 						}
 						try {
-							if (logger.isTraceEnabled()) {
-								logger.trace(MARKER_ROCKSDB, "Reading {}", LLUtils.toStringSafe(key));
-							}
 							while (true) {
 								@Nullable Buffer prevData;
 								var prevDataHolder = existsAlmostCertainly ? null : new Holder<byte[]>();
@@ -824,11 +857,19 @@ public class LLLocalDictionary implements LLDictionary {
 								} else {
 									prevData = null;
 								}
+								if (logger.isTraceEnabled()) {
+									logger.trace(MARKER_ROCKSDB,
+											"Reading {}: {} (before update)",
+											LLUtils.toStringSafe(key),
+											LLUtils.toStringSafe(prevData)
+									);
+								}
 								try {
 									@Nullable Buffer newData;
 									try (Buffer prevDataToSendToUpdater = prevData == null ? null : prevData.copy()) {
-										try (var newDataToReceive = updater.apply(
+										try (var sentData = prevDataToSendToUpdater == null ? null
-												prevDataToSendToUpdater == null ? null : prevDataToSendToUpdater.send())) {
+												: prevDataToSendToUpdater.send()) {
+											try (var newDataToReceive = updater.apply(sentData)) {
 												if (newDataToReceive != null) {
 													newData = newDataToReceive.receive();
 												} else {
@@ -836,7 +877,17 @@ public class LLLocalDictionary implements LLDictionary {
 												}
 											}
 										}
+									}
+									assert newData == null || newData.isAccessible();
 									try {
+										if (logger.isTraceEnabled()) {
+											logger.trace(MARKER_ROCKSDB,
+													"Updating {}. previous data: {}, updated data: {}",
+													LLUtils.toStringSafe(key),
+													LLUtils.toStringSafe(prevData),
+													LLUtils.toStringSafe(newData)
+											);
+										}
 										if (prevData != null && newData == null) {
 											//noinspection DuplicatedCode
 											if (updateMode == UpdateMode.ALLOW) {
@@ -851,7 +902,7 @@ public class LLLocalDictionary implements LLDictionary {
 												}
 											}
 											if (logger.isTraceEnabled()) {
-												logger.trace(MARKER_ROCKSDB, "Deleting {}", LLUtils.toStringSafe(key));
+												logger.trace(MARKER_ROCKSDB, "Deleting {} (after update)", LLUtils.toStringSafe(key));
 											}
 											dbDelete(cfh, null, key.send());
 										} else if (newData != null
@@ -869,8 +920,11 @@ public class LLLocalDictionary implements LLDictionary {
 												}
 											}
 											if (logger.isTraceEnabled()) {
-												logger.trace(MARKER_ROCKSDB, "Writing {}: {}",
+												logger.trace(MARKER_ROCKSDB,
-														LLUtils.toStringSafe(key), LLUtils.toStringSafe(newData));
+														"Writing {}: {} (after update)",
+														LLUtils.toStringSafe(key),
+														LLUtils.toStringSafe(newData)
+												);
 											}
 											assert key.isAccessible();
 											assert newData.isAccessible();
@@ -910,7 +964,7 @@ public class LLLocalDictionary implements LLDictionary {
 			}
 			var validWriteOptions = Objects.requireNonNullElse(writeOptions, EMPTY_WRITE_OPTIONS);
 			if (databaseOptions.allowNettyDirect()) {
-				var keyNioBuffer = LLUtils.convertToDirect(alloc, key.send());
+				var keyNioBuffer = LLUtils.convertToReadableDirect(alloc, key.send());
 				try {
 					db.delete(cfh, validWriteOptions, keyNioBuffer.byteBuffer());
 				} finally {
@@ -986,18 +1040,24 @@ public class LLLocalDictionary implements LLDictionary {
 										stamp = 0;
 									}
 									try {
-										if (logger.isTraceEnabled()) {
-											logger.trace(MARKER_ROCKSDB, "Reading {}", LLUtils.toArray(key));
-										}
 										var data = new Holder<byte[]>();
+										Buffer bufferResult;
 										if (db.keyMayExist(cfh, LLUtils.toArray(key), data)) {
 											if (data.getValue() != null) {
-												return LLUtils.fromByteArray(alloc, data.getValue()).send();
+												bufferResult = LLUtils.fromByteArray(alloc, data.getValue());
 											} else {
-												return dbGet(cfh, null, key.send(), true);
+												try (var bufferResultToReceive = dbGet(cfh, null, key.send(), true)) {
+													bufferResult = bufferResultToReceive == null ? null : bufferResultToReceive.receive();
+												}
 											}
 										} else {
-											return null;
+											bufferResult = null;
+										}
+										try (bufferResult) {
+											if (logger.isTraceEnabled()) {
+												logger.trace(MARKER_ROCKSDB, "Reading {}: {}", LLUtils.toStringSafe(key), LLUtils.toStringSafe(bufferResult));
+											}
+											return bufferResult == null ? null : bufferResult.send();
 										}
 									} finally {
 										if (updateMode == UpdateMode.ALLOW) {
@@ -1176,9 +1236,9 @@ public class LLLocalDictionary implements LLDictionary {
 										batch.close();
 									} else {
 										for (LLEntry entry : entriesWindow) {
-											var k = LLUtils.convertToDirect(alloc, entry.getKey());
+											var k = LLUtils.convertToReadableDirect(alloc, entry.getKey());
 											try {
-												var v = LLUtils.convertToDirect(alloc, entry.getValue());
+												var v = LLUtils.convertToReadableDirect(alloc, entry.getValue());
 												try {
 													db.put(cfh, EMPTY_WRITE_OPTIONS, k.byteBuffer(), v.byteBuffer());
 												} finally {
@@ -1309,9 +1369,9 @@ public class LLLocalDictionary implements LLDictionary {
 							} else {
 								int i = 0;
 								for (Tuple2<Buffer, X> entry : entriesWindow) {
-									var k = LLUtils.convertToDirect(alloc, entry.getT1().send());
+									var k = LLUtils.convertToReadableDirect(alloc, entry.getT1().send());
 									try {
-										var v = LLUtils.convertToDirect(alloc, updatedValuesToWrite.get(i));
+										var v = LLUtils.convertToReadableDirect(alloc, updatedValuesToWrite.get(i));
 										try {
 											db.put(cfh, EMPTY_WRITE_OPTIONS, k.byteBuffer(), v.byteBuffer());
 										} finally {
@@ -1565,7 +1625,8 @@ public class LLLocalDictionary implements LLDictionary {
 		return Flux.usingWhen(rangeMono,
 				rangeSend -> Flux.using(
 						() -> new LLLocalKeyReactiveRocksIterator(db, alloc, cfh, rangeSend,
-								databaseOptions.allowNettyDirect(), resolveSnapshot(snapshot), getRangeKeysMultiDebugName),
+								databaseOptions.allowNettyDirect(), resolveSnapshot(snapshot)
+						),
 						llLocalKeyReactiveRocksIterator -> llLocalKeyReactiveRocksIterator.flux().subscribeOn(dbScheduler),
 						LLLocalReactiveRocksIterator::release
 				).transform(LLUtils::handleDiscard),
@@ -1679,9 +1740,9 @@ public class LLLocalDictionary implements LLDictionary {
 														if (!USE_WRITE_BATCHES_IN_SET_RANGE) {
 															for (LLEntry entry : entriesList) {
 																assert entry.isAccessible();
-																var k = LLUtils.convertToDirect(alloc, entry.getKey());
+																var k = LLUtils.convertToReadableDirect(alloc, entry.getKey());
 																try {
-																	var v = LLUtils.convertToDirect(alloc, entry.getValue());
+																	var v = LLUtils.convertToReadableDirect(alloc, entry.getValue());
 																	try {
 																		db.put(cfh, EMPTY_WRITE_OPTIONS, k.byteBuffer(), v.byteBuffer());
 																	} finally {
@@ -1799,7 +1860,7 @@ public class LLLocalDictionary implements LLDictionary {
 					try {
 						rocksIterator.status();
 						while (rocksIterator.isValid()) {
-							writeBatch.delete(cfh, LLUtils.readDirectNioBuffer(alloc, rocksIterator::key));
+							writeBatch.delete(cfh, LLUtils.readDirectNioBuffer(alloc, rocksIterator::key).send());
 							rocksIterator.next();
 							rocksIterator.status();
 						}
@@ -1874,7 +1935,7 @@ public class LLLocalDictionary implements LLDictionary {
 			Send<Buffer> bufferToReceive) {
 		try (var buffer = bufferToReceive.receive()) {
 			if (allowNettyDirect) {
-				var direct = LLUtils.convertToDirect(alloc, buffer.send());
+				var direct = LLUtils.convertToReadableDirect(alloc, buffer.send());
 				assert direct.byteBuffer().isDirect();
 				rocksIterator.seek(direct.byteBuffer());
 				return () -> {
@@ -1895,7 +1956,7 @@ public class LLLocalDictionary implements LLDictionary {
 			requireNonNull(buffer);
 			AbstractSlice<?> slice;
 			if (allowNettyDirect && LLLocalDictionary.USE_DIRECT_BUFFER_BOUNDS) {
-				var direct = LLUtils.convertToDirect(alloc, buffer.send());
+				var direct = LLUtils.convertToReadableDirect(alloc, buffer.send());
 				buffer = direct.buffer().receive();
 				assert direct.byteBuffer().isDirect();
 				slice = new DirectSlice(direct.byteBuffer(), buffer.readableBytes());
@@ -2123,8 +2184,8 @@ public class LLLocalDictionary implements LLDictionary {
 									try {
 										rocksIterator.status();
 										if (rocksIterator.isValid()) {
-											try (var key = LLUtils.readDirectNioBuffer(alloc, rocksIterator::key).receive()) {
+											try (var key = LLUtils.readDirectNioBuffer(alloc, rocksIterator::key)) {
-												try (var value = LLUtils.readDirectNioBuffer(alloc, rocksIterator::value).receive()) {
+												try (var value = LLUtils.readDirectNioBuffer(alloc, rocksIterator::value)) {
 													return LLEntry.of(key.send(), value.send()).send();
 												}
 											}
@@ -2184,7 +2245,7 @@ public class LLLocalDictionary implements LLDictionary {
 									try {
 										rocksIterator.status();
 										if (rocksIterator.isValid()) {
-											return LLUtils.readDirectNioBuffer(alloc, rocksIterator::key);
+											return LLUtils.readDirectNioBuffer(alloc, rocksIterator::key).send();
 										} else {
 											return null;
 										}
@@ -2354,8 +2415,8 @@ public class LLLocalDictionary implements LLDictionary {
 										if (!rocksIterator.isValid()) {
 											return null;
 										}
-										try (Buffer key = LLUtils.readDirectNioBuffer(alloc, rocksIterator::key).receive()) {
+										try (Buffer key = LLUtils.readDirectNioBuffer(alloc, rocksIterator::key)) {
-											try (Buffer value = LLUtils.readDirectNioBuffer(alloc, rocksIterator::value).receive()) {
+											try (Buffer value = LLUtils.readDirectNioBuffer(alloc, rocksIterator::value)) {
 												dbDelete(cfh, null, key.copy().send());
 												return LLEntry.of(key.send(), value.send()).send();
 											}

src/main/java/it/cavallium/dbengine/database/disk/LLLocalEntryReactiveRocksIterator.java

@@ -18,7 +18,7 @@ public class LLLocalEntryReactiveRocksIterator extends LLLocalReactiveRocksItera
 			boolean allowNettyDirect,
 			ReadOptions readOptions,
 			String debugName) {
-		super(db, alloc, cfh, range, allowNettyDirect, readOptions, true, debugName);
+		super(db, alloc, cfh, range, allowNettyDirect, readOptions, true);
 	}
 
 	@Override

src/main/java/it/cavallium/dbengine/database/disk/LLLocalGroupedReactiveRocksIterator.java

@@ -1,5 +1,7 @@
 package it.cavallium.dbengine.database.disk;
 
+import static it.cavallium.dbengine.database.LLUtils.MARKER_ROCKSDB;
+
 import io.net5.buffer.api.Buffer;
 import io.net5.buffer.api.BufferAllocator;
 import io.net5.buffer.api.Send;
@@ -7,14 +9,18 @@ import it.cavallium.dbengine.database.LLRange;
 import it.cavallium.dbengine.database.LLUtils;
 import it.unimi.dsi.fastutil.objects.ObjectArrayList;
 import java.util.List;
+import org.jetbrains.annotations.Nullable;
 import org.rocksdb.ColumnFamilyHandle;
 import org.rocksdb.ReadOptions;
 import org.rocksdb.RocksDB;
 import org.rocksdb.RocksDBException;
+import org.warp.commonutils.log.Logger;
+import org.warp.commonutils.log.LoggerFactory;
 import reactor.core.publisher.Flux;
 
 public abstract class LLLocalGroupedReactiveRocksIterator<T> {
 
+	protected static final Logger logger = LoggerFactory.getLogger(LLLocalGroupedReactiveRocksIterator.class);
 	private final RocksDB db;
 	private final BufferAllocator alloc;
 	private final ColumnFamilyHandle cfh;
@@ -51,6 +57,9 @@ public abstract class LLLocalGroupedReactiveRocksIterator<T> {
 				.generate(() -> {
 					var readOptions = new ReadOptions(this.readOptions);
 					readOptions.setFillCache(canFillCache && range.hasMin() && range.hasMax());
+					if (logger.isTraceEnabled()) {
+						logger.trace(MARKER_ROCKSDB, "Range {} started", LLUtils.toStringSafe(range));
+					}
 					return LLLocalDictionary.getRocksIterator(alloc, allowNettyDirect, readOptions, range.copy().send(), db, cfh);
 				}, (tuple, sink) -> {
 					try {
@@ -60,29 +69,41 @@ public abstract class LLLocalGroupedReactiveRocksIterator<T> {
 						try {
 							rocksIterator.status();
 							while (rocksIterator.isValid()) {
-								try (Buffer key = LLUtils.readDirectNioBuffer(alloc, rocksIterator::key).receive()) {
+								try (Buffer key = LLUtils.readDirectNioBuffer(alloc, rocksIterator::key)) {
 									if (firstGroupKey == null) {
 										firstGroupKey = key.copy();
 									} else if (!LLUtils.equals(firstGroupKey, firstGroupKey.readerOffset(),
 											key, key.readerOffset(), prefixLength)) {
 										break;
 									}
-									Buffer value;
+									@Nullable Buffer value;
 									if (readValues) {
-										value = LLUtils.readDirectNioBuffer(alloc, rocksIterator::value).receive();
+										value = LLUtils.readDirectNioBuffer(alloc, rocksIterator::value);
 									} else {
-										value = alloc.allocate(0);
+										value = null;
 									}
+
+									if (logger.isTraceEnabled()) {
+										logger.trace(MARKER_ROCKSDB,
+												"Range {} is reading {}: {}",
+												LLUtils.toStringSafe(range),
+												LLUtils.toStringSafe(key),
+												LLUtils.toStringSafe(value)
+										);
+									}
+
 									try {
 										rocksIterator.next();
 										rocksIterator.status();
-										T entry = getEntry(key.send(), value.send());
+										T entry = getEntry(key.send(), value == null ? null : value.send());
 										values.add(entry);
 									} finally {
+										if (value != null) {
 											value.close();
 										}
 									}
 								}
+							}
 						} finally {
 							if (firstGroupKey != null) {
 								firstGroupKey.close();
@@ -91,9 +112,15 @@ public abstract class LLLocalGroupedReactiveRocksIterator<T> {
 						if (!values.isEmpty()) {
 							sink.next(values);
 						} else {
+							if (logger.isTraceEnabled()) {
+								logger.trace(MARKER_ROCKSDB, "Range {} ended", LLUtils.toStringSafe(range));
+							}
 							sink.complete();
 						}
 					} catch (RocksDBException ex) {
+						if (logger.isTraceEnabled()) {
+							logger.trace(MARKER_ROCKSDB, "Range {} failed", LLUtils.toStringSafe(range));
+						}
 						sink.error(ex);
 					}
 					return tuple;
@@ -106,7 +133,7 @@ public abstract class LLLocalGroupedReactiveRocksIterator<T> {
 				});
 	}
 
-	public abstract T getEntry(Send<Buffer> key, Send<Buffer> value);
+	public abstract T getEntry(@Nullable Send<Buffer> key, @Nullable Send<Buffer> value);
 
 	public void release() {
 		range.close();

src/main/java/it/cavallium/dbengine/database/disk/LLLocalKeyPrefixReactiveRocksIterator.java

@@ -1,5 +1,7 @@
 package it.cavallium.dbengine.database.disk;
 
+import static it.cavallium.dbengine.database.LLUtils.MARKER_ROCKSDB;
+
 import io.net5.buffer.api.Buffer;
 import io.net5.buffer.api.BufferAllocator;
 import io.net5.buffer.api.Send;
@@ -9,10 +11,13 @@ import org.rocksdb.ColumnFamilyHandle;
 import org.rocksdb.ReadOptions;
 import org.rocksdb.RocksDB;
 import org.rocksdb.RocksDBException;
+import org.warp.commonutils.log.Logger;
+import org.warp.commonutils.log.LoggerFactory;
 import reactor.core.publisher.Flux;
 
 public class LLLocalKeyPrefixReactiveRocksIterator {
 
+	protected static final Logger logger = LoggerFactory.getLogger(LLLocalKeyPrefixReactiveRocksIterator.class);
 	private final RocksDB db;
 	private final BufferAllocator alloc;
 	private final ColumnFamilyHandle cfh;
@@ -54,6 +59,9 @@ public class LLLocalKeyPrefixReactiveRocksIterator {
 								readOptions.setReadaheadSize(32 * 1024); // 32KiB
 								readOptions.setFillCache(canFillCache);
 							}
+							if (logger.isTraceEnabled()) {
+								logger.trace(MARKER_ROCKSDB, "Range {} started", LLUtils.toStringSafe(range));
+							}
 							return LLLocalDictionary.getRocksIterator(alloc, allowNettyDirect, readOptions, rangeSend, db, cfh);
 						}, (tuple, sink) -> {
 							try {
@@ -64,7 +72,7 @@ public class LLLocalKeyPrefixReactiveRocksIterator {
 									while (rocksIterator.isValid()) {
 										Buffer key;
 										if (allowNettyDirect) {
-											key = LLUtils.readDirectNioBuffer(alloc, rocksIterator::key).receive();
+											key = LLUtils.readDirectNioBuffer(alloc, rocksIterator::key);
 										} else {
 											key = LLUtils.fromByteArray(alloc, rocksIterator.key());
 										}
@@ -79,11 +87,24 @@ public class LLLocalKeyPrefixReactiveRocksIterator {
 											rocksIterator.status();
 										}
 									}
+
 									if (firstGroupKey != null) {
 										var groupKeyPrefix = firstGroupKey.copy(firstGroupKey.readerOffset(), prefixLength);
 										assert groupKeyPrefix.isAccessible();
+
+										if (logger.isTraceEnabled()) {
+											logger.trace(MARKER_ROCKSDB,
+													"Range {} is reading prefix {}",
+													LLUtils.toStringSafe(range),
+													LLUtils.toStringSafe(groupKeyPrefix)
+											);
+										}
+
 										sink.next(groupKeyPrefix.send());
 									} else {
+										if (logger.isTraceEnabled()) {
+											logger.trace(MARKER_ROCKSDB, "Range {} ended", LLUtils.toStringSafe(range));
+										}
 										sink.complete();
 									}
 								} finally {
@@ -92,6 +113,9 @@ public class LLLocalKeyPrefixReactiveRocksIterator {
 									}
 								}
 							} catch (RocksDBException ex) {
+								if (logger.isTraceEnabled()) {
+									logger.trace(MARKER_ROCKSDB, "Range {} failed", LLUtils.toStringSafe(range));
+								}
 								sink.error(ex);
 							}
 							return tuple;

src/main/java/it/cavallium/dbengine/database/disk/LLLocalKeyReactiveRocksIterator.java

@@ -15,9 +15,8 @@ public class LLLocalKeyReactiveRocksIterator extends LLLocalReactiveRocksIterato
 			ColumnFamilyHandle cfh,
 			Send<LLRange> range,
 			boolean allowNettyDirect,
-			ReadOptions readOptions,
+			ReadOptions readOptions) {
-			String debugName) {
+		super(db, alloc, cfh, range, allowNettyDirect, readOptions, false);
-		super(db, alloc, cfh, range, allowNettyDirect, readOptions, false, debugName);
 	}
 
 	@Override

src/main/java/it/cavallium/dbengine/database/disk/LLLocalKeyValueDatabase.java

@@ -100,7 +100,9 @@ public class LLLocalKeyValueDatabase implements LLKeyValueDatabase {
 			}
 			if (!MemorySegmentUtils.isSupported()) {
 				throw new UnsupportedOperationException("Foreign Memory Access API support is disabled."
-						+ " Please set \"--enable-preview --add-modules jdk.incubator.foreign -Dforeign.restricted=permit\"");
+						+ " Please set \"" + MemorySegmentUtils.getSuggestedArgs() + "\"",
+						MemorySegmentUtils.getUnsupportedCause()
+				);
 			}
 		}
 

src/main/java/it/cavallium/dbengine/database/disk/LLLocalLuceneIndex.java

@@ -1,15 +1,15 @@
 package it.cavallium.dbengine.database.disk;
 
 import static it.cavallium.dbengine.database.LLUtils.MARKER_LUCENE;
-import static it.cavallium.dbengine.database.LLUtils.MARKER_ROCKSDB;
+import static it.cavallium.dbengine.lucene.searcher.LLSearchTransformer.NO_TRANSFORMATION;
 
+import io.net5.buffer.api.Send;
 import it.cavallium.dbengine.client.DirectIOOptions;
 import it.cavallium.dbengine.client.IndicizerAnalyzers;
 import it.cavallium.dbengine.client.IndicizerSimilarities;
 import it.cavallium.dbengine.client.LuceneOptions;
 import it.cavallium.dbengine.client.NRTCachingOptions;
 import it.cavallium.dbengine.client.query.current.data.QueryParams;
-import it.cavallium.dbengine.database.EnglishItalianStopFilter;
 import it.cavallium.dbengine.database.LLDocument;
 import it.cavallium.dbengine.database.LLLuceneIndex;
 import it.cavallium.dbengine.database.LLSearchResultShard;
@@ -21,16 +21,16 @@ import it.cavallium.dbengine.lucene.LuceneUtils;
 import it.cavallium.dbengine.lucene.searcher.AdaptiveLuceneLocalSearcher;
 import it.cavallium.dbengine.lucene.searcher.LocalQueryParams;
 import it.cavallium.dbengine.lucene.searcher.LuceneLocalSearcher;
-import it.cavallium.dbengine.lucene.searcher.LuceneShardSearcher;
+import it.cavallium.dbengine.lucene.searcher.LuceneMultiSearcher;
+import it.cavallium.dbengine.lucene.searcher.LLSearchTransformer;
 import java.io.IOException;
 import java.nio.file.Path;
-import java.time.Duration;
-import java.util.HashMap;
 import java.util.Map;
 import java.util.Map.Entry;
 import java.util.Set;
 import java.util.concurrent.Phaser;
 import java.util.concurrent.TimeUnit;
+import org.apache.lucene.analysis.miscellaneous.PerFieldAnalyzerWrapper;
 import org.apache.lucene.index.ConcurrentMergeScheduler;
 import org.apache.lucene.index.IndexWriter;
 import org.apache.lucene.index.IndexWriterConfig;
@@ -39,15 +39,7 @@ import org.apache.lucene.index.MergeScheduler;
 import org.apache.lucene.index.SerialMergeScheduler;
 import org.apache.lucene.index.SnapshotDeletionPolicy;
 import org.apache.lucene.misc.store.DirectIODirectory;
-import org.apache.lucene.queries.mlt.MoreLikeThis;
-import org.apache.lucene.search.BooleanClause.Occur;
-import org.apache.lucene.search.BooleanQuery;
-import org.apache.lucene.search.ConstantScoreQuery;
-import org.apache.lucene.search.MatchAllDocsQuery;
-import org.apache.lucene.search.MatchNoDocsQuery;
-import org.apache.lucene.search.Query;
 import org.apache.lucene.search.similarities.Similarity;
-import org.apache.lucene.search.similarities.TFIDFSimilarity;
 import org.apache.lucene.store.ByteBuffersDirectory;
 import org.apache.lucene.store.Directory;
 import org.apache.lucene.store.FSDirectory;
@@ -73,22 +65,14 @@ public class LLLocalLuceneIndex implements LLLuceneIndex {
 	 * There is only a single thread globally to not overwhelm the disk with
 	 * concurrent commits or concurrent refreshes.
 	 */
-	private static final Scheduler luceneHeavyTasksScheduler = Schedulers.newBoundedElastic(1,
+	private static final Scheduler luceneHeavyTasksScheduler = Schedulers.single(Schedulers.boundedElastic());
-			Schedulers.DEFAULT_BOUNDED_ELASTIC_QUEUESIZE,
-			"lucene",
-			Integer.MAX_VALUE,
-			true
-	);
-	// Scheduler used to get callback values of LuceneStreamSearcher without creating deadlocks
-	protected final Scheduler luceneSearcherScheduler = LuceneUtils.newLuceneSearcherScheduler(false);
-	// Scheduler used to get callback values of LuceneStreamSearcher without creating deadlocks
-	private static final Scheduler luceneWriterScheduler = Schedulers.boundedElastic();
 
 	private final String luceneIndexName;
 	private final IndexWriter indexWriter;
 	private final SnapshotsManager snapshotsManager;
-	private final CachedIndexSearcherManager searcherManager;
+	private final IndexSearcherManager searcherManager;
-	private final Similarity similarity;
+	private final PerFieldAnalyzerWrapper luceneAnalyzer;
+	private final Similarity luceneSimilarity;
 	private final Directory directory;
 	private final boolean lowMemory;
 
@@ -166,7 +150,8 @@ public class LLLocalLuceneIndex implements LLLuceneIndex {
 
 			if (luceneOptions.nrtCachingOptions().isPresent()) {
 				NRTCachingOptions nrtCachingOptions = luceneOptions.nrtCachingOptions().get();
-				directory = new NRTCachingDirectory(directory, nrtCachingOptions.maxMergeSizeMB(), nrtCachingOptions.maxCachedMB());
+				directory = new NRTCachingDirectory(directory, nrtCachingOptions.maxMergeSizeMB(),
+						nrtCachingOptions.maxCachedMB());
 			}
 
 			this.directory = directory;
@@ -175,9 +160,10 @@ public class LLLocalLuceneIndex implements LLLuceneIndex {
 		this.luceneIndexName = name;
 		var snapshotter = new SnapshotDeletionPolicy(new KeepOnlyLastCommitDeletionPolicy());
 		this.lowMemory = lowMemory;
-		this.similarity = LuceneUtils.toPerFieldSimilarityWrapper(indicizerSimilarities);
+		this.luceneAnalyzer = LuceneUtils.toPerFieldAnalyzerWrapper(indicizerAnalyzers);
+		this.luceneSimilarity = LuceneUtils.toPerFieldSimilarityWrapper(indicizerSimilarities);
 
-		IndexWriterConfig indexWriterConfig = new IndexWriterConfig(LuceneUtils.toPerFieldAnalyzerWrapper(indicizerAnalyzers));
+		var indexWriterConfig = new IndexWriterConfig(luceneAnalyzer);
 		indexWriterConfig.setOpenMode(IndexWriterConfig.OpenMode.CREATE_OR_APPEND);
 		indexWriterConfig.setIndexDeletionPolicy(snapshotter);
 		indexWriterConfig.setCommitOnClose(true);
@@ -197,15 +183,16 @@ public class LLLocalLuceneIndex implements LLLuceneIndex {
 			writerSchedulerMaxThreadCount = concurrentMergeScheduler.getMaxThreadCount();
 			mergeScheduler = concurrentMergeScheduler;
 		}
+		logger.trace("WriterSchedulerMaxThreadCount: {}", writerSchedulerMaxThreadCount);
 		indexWriterConfig.setMergeScheduler(mergeScheduler);
 		indexWriterConfig.setRAMBufferSizeMB(luceneOptions.indexWriterBufferSize() / 1024D / 1024D);
 		indexWriterConfig.setReaderPooling(false);
-		indexWriterConfig.setSimilarity(getSimilarity());
+		indexWriterConfig.setSimilarity(getLuceneSimilarity());
 		this.indexWriter = new IndexWriter(directory, indexWriterConfig);
 		this.snapshotsManager = new SnapshotsManager(indexWriter, snapshotter);
 		this.searcherManager = new CachedIndexSearcherManager(indexWriter,
 				snapshotsManager,
-				getSimilarity(),
+				getLuceneSimilarity(),
 				luceneOptions.applyAllDeletes(),
 				luceneOptions.writeAllDeletes(),
 				luceneOptions.queryRefreshDebounceTime()
@@ -217,8 +204,8 @@ public class LLLocalLuceneIndex implements LLLuceneIndex {
 				TimeUnit.MILLISECONDS);
 	}
 
-	private Similarity getSimilarity() {
+	private Similarity getLuceneSimilarity() {
-		return similarity;
+		return luceneSimilarity;
 	}
 
 	@Override
@@ -241,13 +228,12 @@ public class LLLocalLuceneIndex implements LLLuceneIndex {
 		return Mono.<Void>fromCallable(() -> {
 			activeTasks.register();
 			try {
-				//noinspection BlockingMethodInNonBlockingContext
 				indexWriter.addDocument(LLUtils.toDocument(doc));
 				return null;
 			} finally {
 				activeTasks.arriveAndDeregister();
 			}
-		}).subscribeOn(luceneWriterScheduler);
+		}).subscribeOn(Schedulers.boundedElastic());
 	}
 
 	@Override
@@ -258,13 +244,12 @@ public class LLLocalLuceneIndex implements LLLuceneIndex {
 						.<Void>fromCallable(() -> {
 							activeTasks.register();
 							try {
-								//noinspection BlockingMethodInNonBlockingContext
 								indexWriter.addDocuments(LLUtils.toDocumentsFromEntries(documentsList));
 								return null;
 							} finally {
 								activeTasks.arriveAndDeregister();
 							}
-						}).subscribeOn(luceneWriterScheduler)
+						}).subscribeOn(Schedulers.boundedElastic())
 				);
 	}
 
@@ -274,13 +259,12 @@ public class LLLocalLuceneIndex implements LLLuceneIndex {
 		return Mono.<Void>fromCallable(() -> {
 			activeTasks.register();
 			try {
-				//noinspection BlockingMethodInNonBlockingContext
 				indexWriter.deleteDocuments(LLUtils.toTerm(id));
 				return null;
 			} finally {
 				activeTasks.arriveAndDeregister();
 			}
-		}).subscribeOn(luceneWriterScheduler);
+		}).subscribeOn(Schedulers.boundedElastic());
 	}
 
 	@Override
@@ -288,13 +272,12 @@ public class LLLocalLuceneIndex implements LLLuceneIndex {
 		return Mono.<Void>fromCallable(() -> {
 			activeTasks.register();
 			try {
-				//noinspection BlockingMethodInNonBlockingContext
 				indexWriter.updateDocument(LLUtils.toTerm(id), LLUtils.toDocument(document));
 			} finally {
 				activeTasks.arriveAndDeregister();
 			}
 			return null;
-		}).subscribeOn(luceneWriterScheduler);
+		}).subscribeOn(Schedulers.boundedElastic());
 	}
 
 	@Override
@@ -310,7 +293,6 @@ public class LLLocalLuceneIndex implements LLLuceneIndex {
 						for (Entry<LLTerm, LLDocument> entry : documentsMap.entrySet()) {
 							LLTerm key = entry.getKey();
 							LLDocument value = entry.getValue();
-							//noinspection BlockingMethodInNonBlockingContext
 							indexWriter.updateDocument(LLUtils.toTerm(key), LLUtils.toDocument(value));
 						}
 						return null;
@@ -318,7 +300,7 @@ public class LLLocalLuceneIndex implements LLLuceneIndex {
 						activeTasks.arriveAndDeregister();
 					}
 				})
-				.subscribeOn(luceneWriterScheduler);
+				.subscribeOn(Schedulers.boundedElastic());
 	}
 
 	@Override
@@ -340,124 +322,36 @@ public class LLLocalLuceneIndex implements LLLuceneIndex {
 	}
 
 	@Override
-	public Mono<LLSearchResultShard> moreLikeThis(@Nullable LLSnapshot snapshot,
+	public Mono<Send<LLSearchResultShard>> moreLikeThis(@Nullable LLSnapshot snapshot,
 			QueryParams queryParams,
 			String keyFieldName,
 			Flux<Tuple2<String, Set<String>>> mltDocumentFieldsFlux) {
-		return getMoreLikeThisQuery(snapshot, LuceneUtils.toLocalQueryParams(queryParams), mltDocumentFieldsFlux)
+		LocalQueryParams localQueryParams = LuceneUtils.toLocalQueryParams(queryParams);
-				.flatMap(modifiedLocalQuery -> searcherManager.captureIndexSearcher(snapshot)
+		var searcher = this.searcherManager.retrieveSearcher(snapshot);
-						.flatMap(indexSearcher -> {
+		var transformer = new MoreLikeThisTransformer(mltDocumentFieldsFlux);
-							Mono<Void> releaseMono = searcherManager.releaseUsedIndexSearcher(indexSearcher);
-							return localSearcher
-											.collect(indexSearcher.getIndexSearcher(), releaseMono, modifiedLocalQuery, keyFieldName, luceneSearcherScheduler)
-											.map(result -> new LLSearchResultShard(result.results(), result.totalHitsCount(), result.release()))
-											.onErrorResume(ex -> releaseMono.then(Mono.error(ex)));
-						})
-				);
-	}
 
-	public Mono<Void> distributedMoreLikeThis(@Nullable LLSnapshot snapshot,
+		return localSearcher.collect(searcher, localQueryParams, keyFieldName, transformer).map(resultToReceive -> {
-			QueryParams queryParams,
+			var result = resultToReceive.receive();
-			Flux<Tuple2<String, Set<String>>> mltDocumentFieldsFlux,
+			return new LLSearchResultShard(result.results(), result.totalHitsCount(), d -> result.close()).send();
-			LuceneShardSearcher shardSearcher) {
+		}).doOnDiscard(Send.class, Send::close);
-		return getMoreLikeThisQuery(snapshot, LuceneUtils.toLocalQueryParams(queryParams), mltDocumentFieldsFlux)
-				.flatMap(modifiedLocalQuery -> searcherManager.captureIndexSearcher(snapshot)
-						.flatMap(indexSearcher -> {
-							Mono<Void> releaseMono = searcherManager.releaseUsedIndexSearcher(indexSearcher);
-							return shardSearcher
-									.searchOn(indexSearcher.getIndexSearcher(), releaseMono, modifiedLocalQuery, luceneSearcherScheduler)
-									.onErrorResume(ex -> releaseMono.then(Mono.error(ex)));
-						})
-				);
-	}
-
-	public Mono<LocalQueryParams> getMoreLikeThisQuery(@Nullable LLSnapshot snapshot,
-			LocalQueryParams localQueryParams,
-			Flux<Tuple2<String, Set<String>>> mltDocumentFieldsFlux) {
-		Query luceneAdditionalQuery;
-		try {
-			luceneAdditionalQuery = localQueryParams.query();
-		} catch (Exception e) {
-			return Mono.error(e);
-		}
-		return mltDocumentFieldsFlux
-				.collectMap(Tuple2::getT1, Tuple2::getT2, HashMap::new)
-				.flatMap(mltDocumentFields -> {
-					mltDocumentFields.entrySet().removeIf(entry -> entry.getValue().isEmpty());
-					if (mltDocumentFields.isEmpty()) {
-						return Mono.just(new LocalQueryParams(new MatchNoDocsQuery(),
-								localQueryParams.offset(),
-								localQueryParams.limit(),
-								localQueryParams.minCompetitiveScore(),
-								localQueryParams.sort(),
-								localQueryParams.scoreMode()
-						));
-					}
-					return this.searcherManager.search(snapshot, indexSearcher -> Mono.fromCallable(() -> {
-						var mlt = new MoreLikeThis(indexSearcher.getIndexReader());
-						mlt.setAnalyzer(indexWriter.getAnalyzer());
-						mlt.setFieldNames(mltDocumentFields.keySet().toArray(String[]::new));
-						mlt.setMinTermFreq(1);
-						mlt.setMinDocFreq(3);
-						mlt.setMaxDocFreqPct(20);
-						mlt.setBoost(localQueryParams.scoreMode().needsScores());
-						mlt.setStopWords(EnglishItalianStopFilter.getStopWordsString());
-						var similarity = getSimilarity();
-						if (similarity instanceof TFIDFSimilarity) {
-							mlt.setSimilarity((TFIDFSimilarity) similarity);
-						} else {
-							logger.trace(MARKER_ROCKSDB, "Using an unsupported similarity algorithm for MoreLikeThis:"
-									+ " {}. You must use a similarity instance based on TFIDFSimilarity!", similarity);
-						}
-
-						// Get the reference docId and apply it to MoreLikeThis, to generate the query
-						@SuppressWarnings({"unchecked", "rawtypes"})
-						var mltQuery = mlt.like((Map) mltDocumentFields);
-						Query luceneQuery;
-						if (!(luceneAdditionalQuery instanceof MatchAllDocsQuery)) {
-							luceneQuery = new BooleanQuery.Builder()
-									.add(mltQuery, Occur.MUST)
-									.add(new ConstantScoreQuery(luceneAdditionalQuery), Occur.MUST)
-									.build();
-						} else {
-							luceneQuery = mltQuery;
-						}
-
-						return luceneQuery;
-					})
-					.subscribeOn(Schedulers.boundedElastic())
-					.map(luceneQuery -> new LocalQueryParams(luceneQuery,
-							localQueryParams.offset(),
-							localQueryParams.limit(),
-							localQueryParams.minCompetitiveScore(),
-							localQueryParams.sort(),
-							localQueryParams.scoreMode()
-					)));
-				});
 	}
 
 	@Override
-	public Mono<LLSearchResultShard> search(@Nullable LLSnapshot snapshot, QueryParams queryParams, String keyFieldName) {
+	public Mono<Send<LLSearchResultShard>> search(@Nullable LLSnapshot snapshot, QueryParams queryParams,
+			String keyFieldName) {
 		LocalQueryParams localQueryParams = LuceneUtils.toLocalQueryParams(queryParams);
-		return searcherManager.captureIndexSearcher(snapshot).flatMap(indexSearcher -> {
+		var searcher = searcherManager.retrieveSearcher(snapshot);
-			Mono<Void> releaseMono = searcherManager.releaseUsedIndexSearcher(indexSearcher);
+
-			return localSearcher
+		return localSearcher.collect(searcher, localQueryParams, keyFieldName, NO_TRANSFORMATION).map(resultToReceive -> {
-					.collect(indexSearcher.getIndexSearcher(), releaseMono, localQueryParams, keyFieldName, luceneSearcherScheduler)
+			var result = resultToReceive.receive();
-					.map(result -> new LLSearchResultShard(result.results(), result.totalHitsCount(), result.release()))
+			return new LLSearchResultShard(result.results(), result.totalHitsCount(), d -> result.close()).send();
-					.onErrorResume(ex -> releaseMono.then(Mono.error(ex)));
+		}).doOnDiscard(Send.class, Send::close);
-		});
 	}
 
-	public Mono<Void> distributedSearch(@Nullable LLSnapshot snapshot,
+	public Mono<Send<LLIndexSearcher>> retrieveSearcher(@Nullable LLSnapshot snapshot) {
-			QueryParams queryParams,
+		return searcherManager
-			LuceneShardSearcher shardSearcher) {
+				.retrieveSearcher(snapshot)
-		LocalQueryParams localQueryParams = LuceneUtils.toLocalQueryParams(queryParams);
+				.doOnDiscard(Send.class, Send::close);
-		return searcherManager.captureIndexSearcher(snapshot)
-				.flatMap(indexSearcher -> {
-					Mono<Void> releaseMono = searcherManager.releaseUsedIndexSearcher(indexSearcher);
-					return shardSearcher.searchOn(indexSearcher.getIndexSearcher(), releaseMono, localQueryParams, luceneSearcherScheduler)
-							.onErrorResume(ex -> releaseMono.then(Mono.error(ex)));
-				});
 	}
 
 	@Override
@@ -535,4 +429,19 @@ public class LLLocalLuceneIndex implements LLLuceneIndex {
 	public boolean isLowMemoryMode() {
 		return lowMemory;
 	}
+
+	private class MoreLikeThisTransformer implements LLSearchTransformer {
+
+		private final Flux<Tuple2<String, Set<String>>> mltDocumentFieldsFlux;
+
+		public MoreLikeThisTransformer(Flux<Tuple2<String, Set<String>>> mltDocumentFieldsFlux) {
+			this.mltDocumentFieldsFlux = mltDocumentFieldsFlux;
+		}
+
+		@Override
+		public Mono<LocalQueryParams> transform(Mono<TransformerInput> inputMono) {
+			return inputMono.flatMap(input -> LuceneUtils.getMoreLikeThisQuery(input.indexSearchers(), input.queryParams(),
+					luceneAnalyzer, luceneSimilarity, mltDocumentFieldsFlux));
+		}
+	}
 }

src/main/java/it/cavallium/dbengine/database/disk/LLLocalMultiLuceneIndex.java

@@ -1,29 +1,20 @@
 package it.cavallium.dbengine.database.disk;
 
-import com.google.common.cache.Cache;
+import io.net5.buffer.api.Send;
-import com.google.common.cache.CacheBuilder;
-import com.google.common.cache.CacheLoader.InvalidCacheLoadException;
 import it.cavallium.dbengine.client.IndicizerAnalyzers;
 import it.cavallium.dbengine.client.IndicizerSimilarities;
-import it.cavallium.dbengine.client.LuceneIndex;
 import it.cavallium.dbengine.client.LuceneOptions;
 import it.cavallium.dbengine.client.query.current.data.QueryParams;
 import it.cavallium.dbengine.database.LLDocument;
 import it.cavallium.dbengine.database.LLLuceneIndex;
-import it.cavallium.dbengine.database.LLSearchResult;
 import it.cavallium.dbengine.database.LLSearchResultShard;
 import it.cavallium.dbengine.database.LLSnapshot;
 import it.cavallium.dbengine.database.LLTerm;
 import it.cavallium.dbengine.lucene.LuceneUtils;
-import it.cavallium.dbengine.lucene.analyzer.TextFieldsAnalyzer;
-import it.cavallium.dbengine.lucene.analyzer.TextFieldsSimilarity;
 import it.cavallium.dbengine.lucene.searcher.AdaptiveLuceneMultiSearcher;
+import it.cavallium.dbengine.lucene.searcher.LLSearchTransformer;
 import it.cavallium.dbengine.lucene.searcher.LocalQueryParams;
 import it.cavallium.dbengine.lucene.searcher.LuceneMultiSearcher;
-import it.cavallium.dbengine.lucene.searcher.LuceneShardSearcher;
-import it.unimi.dsi.fastutil.longs.Long2ObjectMap;
-import it.unimi.dsi.fastutil.longs.Long2ObjectOpenHashMap;
-import it.unimi.dsi.fastutil.objects.Object2ObjectArrayMap;
 import java.io.IOException;
 import java.nio.file.Path;
 import java.time.Duration;
@@ -33,38 +24,24 @@ import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.Map.Entry;
-import java.util.Objects;
 import java.util.Optional;
 import java.util.Set;
 import java.util.concurrent.ConcurrentHashMap;
-import java.util.concurrent.CopyOnWriteArrayList;
-import java.util.concurrent.ExecutionException;
-import java.util.concurrent.ExecutorService;
-import java.util.concurrent.Executors;
-import java.util.concurrent.atomic.AtomicInteger;
 import java.util.concurrent.atomic.AtomicLong;
-import org.apache.lucene.search.CollectionStatistics;
+import org.apache.lucene.analysis.miscellaneous.PerFieldAnalyzerWrapper;
-import org.apache.lucene.search.IndexSearcher;
+import org.apache.lucene.search.similarities.PerFieldSimilarityWrapper;
 import org.jetbrains.annotations.Nullable;
-import org.warp.commonutils.batch.ParallelUtils;
-import org.warp.commonutils.functional.IOBiConsumer;
 import reactor.core.publisher.Flux;
-import reactor.core.publisher.GroupedFlux;
 import reactor.core.publisher.Mono;
-import reactor.core.scheduler.Scheduler;
-import reactor.core.scheduler.Schedulers;
 import reactor.util.function.Tuple2;
-import reactor.util.function.Tuples;
 
 public class LLLocalMultiLuceneIndex implements LLLuceneIndex {
 
-	// Scheduler used to get callback values of LuceneStreamSearcher without creating deadlocks
-	protected final Scheduler luceneSearcherScheduler = LuceneUtils.newLuceneSearcherScheduler(true);
-
 	private final ConcurrentHashMap<Long, LLSnapshot[]> registeredSnapshots = new ConcurrentHashMap<>();
 	private final AtomicLong nextSnapshotNumber = new AtomicLong(1);
 	private final LLLocalLuceneIndex[] luceneIndices;
-
+	private final PerFieldAnalyzerWrapper luceneAnalyzer;
+	private final PerFieldSimilarityWrapper luceneSimilarity;
 
 	private final LuceneMultiSearcher multiSearcher = new AdaptiveLuceneMultiSearcher();
 
@@ -95,6 +72,8 @@ public class LLLocalMultiLuceneIndex implements LLLuceneIndex {
 			);
 		}
 		this.luceneIndices = luceneIndices;
+		this.luceneAnalyzer = LuceneUtils.toPerFieldAnalyzerWrapper(indicizerAnalyzers);
+		this.luceneSimilarity = LuceneUtils.toPerFieldSimilarityWrapper(indicizerSimilarities);
 	}
 
 	private LLLocalLuceneIndex getLuceneIndex(LLTerm id) {
@@ -110,6 +89,19 @@ public class LLLocalMultiLuceneIndex implements LLLuceneIndex {
 		return luceneIndices[0].getLuceneIndexName();
 	}
 
+	private Mono<Send<LLIndexSearchers>> getIndexSearchers(LLSnapshot snapshot) {
+		return Flux
+				.fromArray(luceneIndices)
+				.index()
+				// Resolve the snapshot of each shard
+				.flatMap(tuple -> Mono
+						.fromCallable(() -> resolveSnapshotOptional(snapshot, (int) (long) tuple.getT1()))
+						.flatMap(luceneSnapshot -> tuple.getT2().retrieveSearcher(luceneSnapshot.orElse(null)))
+				)
+				.collectList()
+				.map(searchers -> LLIndexSearchers.of(searchers).send());
+	}
+
 	@Override
 	public Mono<Void> addDocument(LLTerm id, LLDocument doc) {
 		return getLuceneIndex(id).addDocument(id, doc);
@@ -200,60 +192,43 @@ public class LLLocalMultiLuceneIndex implements LLLuceneIndex {
 	}
 
 	@Override
-	public Mono<LLSearchResultShard> moreLikeThis(@Nullable LLSnapshot snapshot,
+	public Mono<Send<LLSearchResultShard>> moreLikeThis(@Nullable LLSnapshot snapshot,
 			QueryParams queryParams,
 			String keyFieldName,
 			Flux<Tuple2<String, Set<String>>> mltDocumentFields) {
 		LocalQueryParams localQueryParams = LuceneUtils.toLocalQueryParams(queryParams);
-		record LuceneIndexWithSnapshot(LLLocalLuceneIndex luceneIndex, Optional<LLSnapshot> snapshot) {}
+		var searchers = this.getIndexSearchers(snapshot);
+		var transformer = new MultiMoreLikeThisTransformer(mltDocumentFields);
 
-		return multiSearcher
-				// Create shard searcher
-				.createShardSearcher(localQueryParams)
-				.flatMap(shardSearcher -> Flux
-						// Iterate the indexed shards
-						.fromArray(luceneIndices).index()
-						// Resolve the snapshot of each shard
-						.flatMap(tuple -> Mono
-								.fromCallable(() -> resolveSnapshotOptional(snapshot, (int) (long) tuple.getT1()))
-								.map(luceneSnapshot -> new LuceneIndexWithSnapshot(tuple.getT2(), luceneSnapshot))
-						)
-						// Execute the query and collect it using the shard searcher
-						.flatMap(luceneIndexWithSnapshot -> luceneIndexWithSnapshot.luceneIndex()
-								.distributedMoreLikeThis(luceneIndexWithSnapshot.snapshot.orElse(null), queryParams, mltDocumentFields, shardSearcher))
 		// Collect all the shards results into a single global result
-						.then(shardSearcher.collect(localQueryParams, keyFieldName, luceneSearcherScheduler))
+		return multiSearcher
-				)
+				.collectMulti(searchers, localQueryParams, keyFieldName, transformer)
-				// Fix the result type
+				// Transform the result type
-				.map(result -> new LLSearchResultShard(result.results(), result.totalHitsCount(), result.release()));
+				.map(resultToReceive -> {
+					var result = resultToReceive.receive();
+					return new LLSearchResultShard(result.results(), result.totalHitsCount(),
+							d -> result.close()).send();
+				})
+				.doOnDiscard(Send.class, Send::close);
 	}
 
 	@Override
-	public Mono<LLSearchResultShard> search(@Nullable LLSnapshot snapshot,
+	public Mono<Send<LLSearchResultShard>> search(@Nullable LLSnapshot snapshot,
 			QueryParams queryParams,
 			String keyFieldName) {
 		LocalQueryParams localQueryParams = LuceneUtils.toLocalQueryParams(queryParams);
-		record LuceneIndexWithSnapshot(LLLocalLuceneIndex luceneIndex, Optional<LLSnapshot> snapshot) {}
+		var searchers = getIndexSearchers(snapshot);
 
-		return multiSearcher
-				// Create shard searcher
-				.createShardSearcher(localQueryParams)
-				.flatMap(shardSearcher -> Flux
-						// Iterate the indexed shards
-						.fromArray(luceneIndices).index()
-						// Resolve the snapshot of each shard
-						.flatMap(tuple -> Mono
-								.fromCallable(() -> resolveSnapshotOptional(snapshot, (int) (long) tuple.getT1()))
-								.map(luceneSnapshot -> new LuceneIndexWithSnapshot(tuple.getT2(), luceneSnapshot))
-						)
-						// Execute the query and collect it using the shard searcher
-						.flatMap(luceneIndexWithSnapshot -> luceneIndexWithSnapshot.luceneIndex()
-								.distributedSearch(luceneIndexWithSnapshot.snapshot.orElse(null), queryParams, shardSearcher))
 		// Collect all the shards results into a single global result
-						.then(shardSearcher.collect(localQueryParams, keyFieldName, luceneSearcherScheduler))
+		return multiSearcher
-				)
+				.collectMulti(searchers, localQueryParams, keyFieldName, LLSearchTransformer.NO_TRANSFORMATION)
-				// Fix the result type
+				// Transform the result type
-				.map(result -> new LLSearchResultShard(result.results(), result.totalHitsCount(), result.release()));
+				.map(resultToReceive -> {
+					var result = resultToReceive.receive();
+					return new LLSearchResultShard(result.results(), result.totalHitsCount(),
+							d -> result.close()).send();
+				})
+				.doOnDiscard(Send.class, Send::close);
 	}
 
 	@Override
@@ -313,4 +288,19 @@ public class LLLocalMultiLuceneIndex implements LLLuceneIndex {
 	public boolean isLowMemoryMode() {
 		return luceneIndices[0].isLowMemoryMode();
 	}
+
+	private class MultiMoreLikeThisTransformer implements LLSearchTransformer {
+
+		private final Flux<Tuple2<String, Set<String>>> mltDocumentFields;
+
+		public MultiMoreLikeThisTransformer(Flux<Tuple2<String, Set<String>>> mltDocumentFields) {
+			this.mltDocumentFields = mltDocumentFields;
+		}
+
+		@Override
+		public Mono<LocalQueryParams> transform(Mono<TransformerInput> inputMono) {
+			return inputMono.flatMap(input -> LuceneUtils.getMoreLikeThisQuery(input.indexSearchers(), input.queryParams(),
+					luceneAnalyzer, luceneSimilarity, mltDocumentFields));
+		}
+	}
 }

src/main/java/it/cavallium/dbengine/database/disk/LLLocalReactiveRocksIterator.java

@@ -1,5 +1,6 @@
 package it.cavallium.dbengine.database.disk;
 
+import static it.cavallium.dbengine.database.LLUtils.MARKER_ROCKSDB;
 import static it.cavallium.dbengine.database.disk.LLLocalDictionary.getRocksIterator;
 
 import io.net5.buffer.api.Buffer;
@@ -9,14 +10,18 @@ import io.net5.util.IllegalReferenceCountException;
 import it.cavallium.dbengine.database.LLRange;
 import it.cavallium.dbengine.database.LLUtils;
 import java.util.concurrent.atomic.AtomicBoolean;
+import org.jetbrains.annotations.Nullable;
 import org.rocksdb.ColumnFamilyHandle;
 import org.rocksdb.ReadOptions;
 import org.rocksdb.RocksDB;
 import org.rocksdb.RocksDBException;
+import org.warp.commonutils.log.Logger;
+import org.warp.commonutils.log.LoggerFactory;
 import reactor.core.publisher.Flux;
 
 public abstract class LLLocalReactiveRocksIterator<T> {
 
+	protected static final Logger logger = LoggerFactory.getLogger(LLLocalReactiveRocksIterator.class);
 	private final AtomicBoolean released = new AtomicBoolean(false);
 	private final RocksDB db;
 	private final BufferAllocator alloc;
@@ -25,7 +30,6 @@ public abstract class LLLocalReactiveRocksIterator<T> {
 	private final boolean allowNettyDirect;
 	private final ReadOptions readOptions;
 	private final boolean readValues;
-	private final String debugName;
 
 	public LLLocalReactiveRocksIterator(RocksDB db,
 			BufferAllocator alloc,
@@ -33,8 +37,7 @@ public abstract class LLLocalReactiveRocksIterator<T> {
 			Send<LLRange> range,
 			boolean allowNettyDirect,
 			ReadOptions readOptions,
-			boolean readValues,
+			boolean readValues) {
-			String debugName) {
 		this.db = db;
 		this.alloc = alloc;
 		this.cfh = cfh;
@@ -42,7 +45,6 @@ public abstract class LLLocalReactiveRocksIterator<T> {
 		this.allowNettyDirect = allowNettyDirect;
 		this.readOptions = readOptions;
 		this.readValues = readValues;
-		this.debugName = debugName;
 	}
 
 	public Flux<T> flux() {
@@ -53,6 +55,9 @@ public abstract class LLLocalReactiveRocksIterator<T> {
 						readOptions.setReadaheadSize(32 * 1024); // 32KiB
 						readOptions.setFillCache(false);
 					}
+					if (logger.isTraceEnabled()) {
+						logger.trace(MARKER_ROCKSDB, "Range {} started", LLUtils.toStringSafe(range));
+					}
 					return getRocksIterator(alloc, allowNettyDirect, readOptions, range.copy().send(), db, cfh);
 				}, (tuple, sink) -> {
 					try {
@@ -61,7 +66,7 @@ public abstract class LLLocalReactiveRocksIterator<T> {
 						if (rocksIterator.isValid()) {
 							Buffer key;
 							if (allowNettyDirect) {
-								key = LLUtils.readDirectNioBuffer(alloc, rocksIterator::key).receive();
+								key = LLUtils.readDirectNioBuffer(alloc, rocksIterator::key);
 							} else {
 								key = LLUtils.fromByteArray(alloc, rocksIterator.key());
 							}
@@ -69,25 +74,43 @@ public abstract class LLLocalReactiveRocksIterator<T> {
 								Buffer value;
 								if (readValues) {
 									if (allowNettyDirect) {
-										value = LLUtils.readDirectNioBuffer(alloc, rocksIterator::value).receive();
+										value = LLUtils.readDirectNioBuffer(alloc, rocksIterator::value);
 									} else {
 										value = LLUtils.fromByteArray(alloc, rocksIterator.value());
 									}
 								} else {
-									value = alloc.allocate(0);
+									value = null;
 								}
+
+								if (logger.isTraceEnabled()) {
+									logger.trace(MARKER_ROCKSDB,
+											"Range {} is reading {}: {}",
+											LLUtils.toStringSafe(range),
+											LLUtils.toStringSafe(key),
+											LLUtils.toStringSafe(value)
+									);
+								}
+
 								try {
 									rocksIterator.next();
 									rocksIterator.status();
-									sink.next(getEntry(key.send(), value.send()));
+									sink.next(getEntry(key.send(), value == null ? null : value.send()));
 								} finally {
+									if (value != null) {
 										value.close();
 									}
 								}
+							}
 						} else {
+							if (logger.isTraceEnabled()) {
+								logger.trace(MARKER_ROCKSDB, "Range {} ended", LLUtils.toStringSafe(range));
+							}
 							sink.complete();
 						}
 					} catch (RocksDBException ex) {
+						if (logger.isTraceEnabled()) {
+							logger.trace(MARKER_ROCKSDB, "Range {} failed", LLUtils.toStringSafe(range));
+						}
 						sink.error(ex);
 					}
 					return tuple;
@@ -100,7 +123,7 @@ public abstract class LLLocalReactiveRocksIterator<T> {
 				});
 	}
 
-	public abstract T getEntry(Send<Buffer> key, Send<Buffer> value);
+	public abstract T getEntry(@Nullable Send<Buffer> key, @Nullable Send<Buffer> value);
 
 	public void release() {
 		if (released.compareAndSet(false, true)) {

src/main/java/it/cavallium/dbengine/database/disk/MemorySegmentUtils.java

@@ -17,32 +17,29 @@ public class MemorySegmentUtils {
 	private static final Object NATIVE;
 
 	static {
-		Lookup lookup = MethodHandles.publicLookup();
+		Lookup lookup = MethodHandles.lookup();
 
 		Object nativeVal = null;
 
-		MethodHandle ofNativeRestricted;
+		var ofNativeRestricted = getJava16NativeRestricted(lookup);
-		try {
+		if (ofNativeRestricted == null) {
-			ofNativeRestricted = lookup.findStatic(Class.forName("jdk.incubator.foreign.MemorySegment"),
+			cause = null;
-					"ofNativeRestricted",
+			ofNativeRestricted = getJava17NativeRestricted(lookup);
-					MethodType.methodType(Class.forName("jdk.incubator.foreign.MemorySegment"))
+		}
-			);
+		if (ofNativeRestricted != null) {
 			try {
 				nativeVal = ofNativeRestricted.invoke();
 			} catch (Throwable e) {
 				cause = e;
 			}
-		} catch (NoSuchMethodException | IllegalAccessException | ClassNotFoundException e) {
-			ofNativeRestricted = null;
-			cause = e;
 		}
 		OF_NATIVE_RESTRICTED = ofNativeRestricted;
 
 		MethodHandle asSlice;
 		try {
-			asSlice = lookup.findVirtual(Class.forName("jdk.incubator.foreign.MemorySegment"),
+			asSlice = lookup.findVirtual(lookup.findClass("jdk.incubator.foreign.MemorySegment"),
 					"asSlice",
-					MethodType.methodType(Class.forName("jdk.incubator.foreign.MemorySegment"), long.class, long.class)
+					MethodType.methodType(lookup.findClass("jdk.incubator.foreign.MemorySegment"), long.class, long.class)
 			);
 		} catch (NoSuchMethodException | IllegalAccessException | ClassNotFoundException e) {
 			asSlice = null;
@@ -52,7 +49,7 @@ public class MemorySegmentUtils {
 
 		MethodHandle asByteBuffer;
 		try {
-			asByteBuffer = lookup.findVirtual(Class.forName("jdk.incubator.foreign.MemorySegment"),
+			asByteBuffer = lookup.findVirtual(lookup.findClass("jdk.incubator.foreign.MemorySegment"),
 					"asByteBuffer", MethodType.methodType(ByteBuffer.class));
 		} catch (NoSuchMethodException | IllegalAccessException | ClassNotFoundException e) {
 			asByteBuffer = null;
@@ -63,6 +60,36 @@ public class MemorySegmentUtils {
 		NATIVE = nativeVal;
 	}
 
+	@SuppressWarnings("JavaLangInvokeHandleSignature")
+	private static MethodHandle getJava16NativeRestricted(Lookup lookup) {
+		MethodHandle ofNativeRestricted;
+		try {
+			ofNativeRestricted = lookup.findStatic(lookup.findClass("jdk.incubator.foreign.MemorySegment"),
+					"ofNativeRestricted",
+					MethodType.methodType(lookup.findClass("jdk.incubator.foreign.MemorySegment"))
+			);
+		} catch (NoSuchMethodException | IllegalAccessException | ClassNotFoundException e) {
+			ofNativeRestricted = null;
+			cause = e;
+		}
+		return ofNativeRestricted;
+	}
+
+	@SuppressWarnings("JavaLangInvokeHandleSignature")
+	private static MethodHandle getJava17NativeRestricted(Lookup lookup) {
+		MethodHandle ofNativeRestricted;
+		try {
+			ofNativeRestricted = lookup.findStatic(lookup.findClass("jdk.incubator.foreign.MemorySegment"),
+					"globalNativeSegment",
+					MethodType.methodType(lookup.findClass("jdk.incubator.foreign.MemorySegment"))
+			);
+		} catch (NoSuchMethodException | IllegalAccessException | ClassNotFoundException e) {
+			ofNativeRestricted = null;
+			cause = e;
+		}
+		return ofNativeRestricted;
+	}
+
 	public static ByteBuffer directBuffer(long address, long size) {
 		if (address <= 0) {
 			throw new IllegalArgumentException("Address is " + address);
@@ -76,13 +103,15 @@ public class MemorySegmentUtils {
 					return PlatformDependent.directBuffer(address, (int) size);
 				}
 				throw new UnsupportedOperationException("Foreign Memory Access API is disabled!"
-						+ " Please set \"--enable-preview --add-modules jdk.incubator.foreign -Dforeign.restricted=permit\"");
+						+ " Please set \"" + MemorySegmentUtils.getSuggestedArgs() + "\"",
+						getUnsupportedCause()
+				);
 			}
 			var memorySegment = AS_SLICE.invoke(NATIVE, address, size);
 			return (ByteBuffer) AS_BYTE_BUFFER.invoke(memorySegment);
 		} catch (Throwable e) {
 			throw new UnsupportedOperationException("Foreign Memory Access API is disabled!"
-					+ " Please set \"--enable-preview --add-modules jdk.incubator.foreign -Dforeign.restricted=permit\"", e);
+					+ " Please set \"" + MemorySegmentUtils.getSuggestedArgs() + "\"", e);
 		}
 	}
 
@@ -93,4 +122,8 @@ public class MemorySegmentUtils {
 	public static Throwable getUnsupportedCause() {
 		return cause;
 	}
+
+	public static String getSuggestedArgs() {
+		return "--enable-preview --add-modules jdk.incubator.foreign -Dforeign.restricted=permit --enable-native-access=ALL-UNNAMED";
+	}
 }

src/main/java/it/cavallium/dbengine/database/serialization/BufferDataInput.java

@@ -6,15 +6,17 @@ import it.cavallium.dbengine.database.SafeCloseable;
 import java.io.DataInput;
 import java.nio.charset.StandardCharsets;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
 public class BufferDataInput implements DataInput, SafeCloseable {
 
+	@Nullable
 	private final Buffer buf;
 	private final int initialReaderOffset;
 
-	public BufferDataInput(Send<Buffer> bufferSend) {
+	public BufferDataInput(@Nullable Send<Buffer> bufferSend) {
-		this.buf = bufferSend.receive().makeReadOnly();
+		this.buf = bufferSend == null ? null : bufferSend.receive().makeReadOnly();
-		this.initialReaderOffset = buf.readerOffset();
+		this.initialReaderOffset = buf == null ? 0 : buf.readerOffset();
 	}
 
 	@Override
@@ -24,75 +26,100 @@ public class BufferDataInput implements DataInput, SafeCloseable {
 
 	@Override
 	public void readFully(byte @NotNull [] b, int off, int len) {
+		if (buf == null) {
+			if (len != 0) {
+				throw new IndexOutOfBoundsException();
+			}
+		} else {
 			buf.copyInto(buf.readerOffset(), b, off, len);
 			buf.readerOffset(buf.readerOffset() + len);
 		}
+	}
 
 	@Override
 	public int skipBytes(int n) {
+		if (buf == null) {
+			if (n != 0) {
+				throw new IndexOutOfBoundsException();
+			}
+			return 0;
+		} else {
 			n = Math.min(n, buf.readerOffset() - buf.writerOffset());
 			buf.readerOffset(buf.readerOffset() + n);
 			return n;
 		}
+	}
 
 	@Override
 	public boolean readBoolean() {
+		if (buf == null) throw new IndexOutOfBoundsException();
 		return buf.readUnsignedByte() != 0;
 	}
 
 	@Override
 	public byte readByte() {
+		if (buf == null) throw new IndexOutOfBoundsException();
 		return buf.readByte();
 	}
 
 	@Override
 	public int readUnsignedByte() {
+		if (buf == null) throw new IndexOutOfBoundsException();
 		return buf.readUnsignedByte();
 	}
 
 	@Override
 	public short readShort() {
+		if (buf == null) throw new IndexOutOfBoundsException();
 		return buf.readShort();
 	}
 
 	@Override
 	public int readUnsignedShort() {
+		if (buf == null) throw new IndexOutOfBoundsException();
 		return buf.readUnsignedShort();
 	}
 
 	@Override
 	public char readChar() {
+		if (buf == null) throw new IndexOutOfBoundsException();
 		return buf.readChar();
 	}
 
 	@Override
 	public int readInt() {
+		if (buf == null) throw new IndexOutOfBoundsException();
 		return buf.readInt();
 	}
 
 	@Override
 	public long readLong() {
+		if (buf == null) throw new IndexOutOfBoundsException();
 		return buf.readLong();
 	}
 
 	@Override
 	public float readFloat() {
+		if (buf == null) throw new IndexOutOfBoundsException();
 		return buf.readFloat();
 	}
 
 	@Override
 	public double readDouble() {
+		if (buf == null) throw new IndexOutOfBoundsException();
 		return buf.readDouble();
 	}
 
 	@Override
 	public String readLine() {
+		if (buf == null) throw new IndexOutOfBoundsException();
 		throw new UnsupportedOperationException();
 	}
 
 	@NotNull
 	@Override
 	public String readUTF() {
+		if (buf == null) throw new IndexOutOfBoundsException();
 		var len = buf.readUnsignedShort();
 		byte[] bytes = new byte[len];
 		buf.copyInto(buf.readerOffset(), bytes, 0, len);
@@ -102,10 +129,16 @@ public class BufferDataInput implements DataInput, SafeCloseable {
 
 	@Override
 	public void close() {
+		if (buf != null) {
 			buf.close();
 		}
+	}
 
 	public int getReadBytesCount() {
+		if (buf == null) {
+			return 0;
+		} else {
 			return buf.readerOffset() - initialReaderOffset;
 		}
 	}
+}

src/main/java/it/cavallium/dbengine/database/serialization/CodecSerializer.java

@@ -6,6 +6,7 @@ import io.net5.buffer.api.Send;
 import java.io.IOError;
 import java.io.IOException;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 import org.warp.commonutils.error.IndexOutOfBoundsException;
 
 public class CodecSerializer<A> implements Serializer<A> {
@@ -37,7 +38,7 @@ public class CodecSerializer<A> implements Serializer<A> {
 	}
 
 	@Override
-	public @NotNull DeserializationResult<A> deserialize(@NotNull Send<Buffer> serializedToReceive) {
+	public @NotNull DeserializationResult<A> deserialize(@Nullable Send<Buffer> serializedToReceive) {
 		try (var is = new BufferDataInput(serializedToReceive)) {
 			int codecId;
 			if (microCodecs) {

src/main/java/it/cavallium/dbengine/database/serialization/Serializer.java

@@ -4,8 +4,11 @@ import io.net5.buffer.api.Buffer;
 import io.net5.buffer.api.BufferAllocator;
 import io.net5.buffer.api.Send;
 import it.cavallium.dbengine.database.LLUtils;
+import it.cavallium.dbengine.netty.NullableBuffer;
 import java.nio.charset.StandardCharsets;
+import java.util.Objects;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
 public interface Serializer<A> {
 
@@ -37,7 +40,8 @@ public interface Serializer<A> {
 	static Serializer<String> utf8(BufferAllocator allocator) {
 		return new Serializer<>() {
 			@Override
-			public @NotNull DeserializationResult<String> deserialize(@NotNull Send<Buffer> serializedToReceive) {
+			public @NotNull DeserializationResult<String> deserialize(@Nullable Send<Buffer> serializedToReceive) {
+				Objects.requireNonNull(serializedToReceive);
 				try (Buffer serialized = serializedToReceive.receive()) {
 					assert serialized.isAccessible();
 					int length = serialized.readInt();

src/main/java/it/cavallium/dbengine/database/serialization/SerializerFixedBinaryLength.java

@@ -5,7 +5,9 @@ import io.net5.buffer.api.BufferAllocator;
 import io.net5.buffer.api.Send;
 import it.cavallium.dbengine.database.LLUtils;
 import java.nio.charset.StandardCharsets;
+import java.util.Objects;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
 @SuppressWarnings("unused")
 public interface SerializerFixedBinaryLength<A> extends Serializer<A> {
@@ -16,6 +18,7 @@ public interface SerializerFixedBinaryLength<A> extends Serializer<A> {
 		return new SerializerFixedBinaryLength<>() {
 			@Override
 			public @NotNull DeserializationResult<Send<Buffer>> deserialize(@NotNull Send<Buffer> serialized) {
+				Objects.requireNonNull(serialized);
 				try (var buf = serialized.receive()) {
 					if (buf.readableBytes() != getSerializedBinaryLength()) {
 						throw new IllegalArgumentException(
@@ -68,7 +71,9 @@ public interface SerializerFixedBinaryLength<A> extends Serializer<A> {
 				// UTF-8 uses max. 3 bytes per char, so calculate the worst case.
 				try (Buffer buf = allocator.allocate(LLUtils.utf8MaxBytes(deserialized))) {
 					assert buf.isAccessible();
-					buf.writeBytes(deserialized.getBytes(StandardCharsets.UTF_8));
+					var bytes = deserialized.getBytes(StandardCharsets.UTF_8);
+					buf.ensureWritable(bytes.length);
+					buf.writeBytes(bytes);
 					if (buf.readableBytes() != getSerializedBinaryLength()) {
 						throw new SerializationException("Fixed serializer with " + getSerializedBinaryLength()
 								+ " bytes has tried to serialize an element with "
@@ -90,6 +95,7 @@ public interface SerializerFixedBinaryLength<A> extends Serializer<A> {
 		return new SerializerFixedBinaryLength<>() {
 			@Override
 			public @NotNull DeserializationResult<Integer> deserialize(@NotNull Send<Buffer> serializedToReceive) {
+				Objects.requireNonNull(serializedToReceive);
 				try (var serialized = serializedToReceive.receive()) {
 					if (serialized.readableBytes() != getSerializedBinaryLength()) {
 						throw new IllegalArgumentException(
@@ -118,6 +124,7 @@ public interface SerializerFixedBinaryLength<A> extends Serializer<A> {
 		return new SerializerFixedBinaryLength<>() {
 			@Override
 			public @NotNull DeserializationResult<Long> deserialize(@NotNull Send<Buffer> serializedToReceive) {
+				Objects.requireNonNull(serializedToReceive);
 				try (var serialized = serializedToReceive.receive()) {
 					if (serialized.readableBytes() != getSerializedBinaryLength()) {
 						throw new IllegalArgumentException(

src/main/java/it/cavallium/dbengine/lucene/LuceneUtils.java

@@ -3,37 +3,39 @@ package it.cavallium.dbengine.lucene;
 import it.cavallium.dbengine.client.CompositeSnapshot;
 import it.cavallium.dbengine.client.IndicizerAnalyzers;
 import it.cavallium.dbengine.client.IndicizerSimilarities;
-import it.cavallium.dbengine.client.query.BasicType;
 import it.cavallium.dbengine.client.query.QueryParser;
 import it.cavallium.dbengine.client.query.current.data.QueryParams;
 import it.cavallium.dbengine.client.query.current.data.TotalHitsCount;
+import it.cavallium.dbengine.database.EnglishItalianStopFilter;
 import it.cavallium.dbengine.database.LLKeyScore;
-import it.cavallium.dbengine.database.LLScoreMode;
+import it.cavallium.dbengine.database.LLSnapshot;
+import it.cavallium.dbengine.database.LLUtils;
 import it.cavallium.dbengine.database.collections.DatabaseMapDictionary;
 import it.cavallium.dbengine.database.collections.DatabaseMapDictionaryDeep;
 import it.cavallium.dbengine.database.collections.ValueGetter;
+import it.cavallium.dbengine.database.disk.LLIndexSearcher;
+import it.cavallium.dbengine.database.disk.LLIndexSearchers;
 import it.cavallium.dbengine.lucene.analyzer.NCharGramAnalyzer;
 import it.cavallium.dbengine.lucene.analyzer.NCharGramEdgeAnalyzer;
 import it.cavallium.dbengine.lucene.analyzer.TextFieldsAnalyzer;
 import it.cavallium.dbengine.lucene.analyzer.TextFieldsSimilarity;
 import it.cavallium.dbengine.lucene.analyzer.WordAnalyzer;
-import it.cavallium.dbengine.lucene.searcher.IndexSearchers;
+import it.cavallium.dbengine.lucene.mlt.MultiMoreLikeThis;
+import it.cavallium.dbengine.lucene.searcher.ExponentialPageLimits;
 import it.cavallium.dbengine.lucene.searcher.LocalQueryParams;
-import it.cavallium.dbengine.lucene.searcher.LuceneMultiSearcher;
+import it.cavallium.dbengine.lucene.searcher.PageLimits;
 import it.cavallium.dbengine.lucene.similarity.NGramSimilarity;
 import java.io.EOFException;
 import java.io.IOException;
 import java.nio.ByteBuffer;
 import java.nio.channels.FileChannel;
-import java.util.Arrays;
 import java.util.Comparator;
 import java.util.HashMap;
+import java.util.List;
 import java.util.Map;
 import java.util.Map.Entry;
 import java.util.NoSuchElementException;
-import java.util.Objects;
 import java.util.Set;
-import java.util.function.Function;
 import java.util.stream.Collectors;
 import org.apache.lucene.analysis.Analyzer;
 import org.apache.lucene.analysis.LowerCaseFilter;
@@ -46,7 +48,14 @@ import org.apache.lucene.analysis.standard.StandardAnalyzer;
 import org.apache.lucene.document.Document;
 import org.apache.lucene.index.IndexReader;
 import org.apache.lucene.index.IndexableField;
+import org.apache.lucene.search.BooleanClause.Occur;
+import org.apache.lucene.search.BooleanQuery;
+import org.apache.lucene.search.ConstantScoreQuery;
 import org.apache.lucene.search.FieldDoc;
+import org.apache.lucene.search.IndexSearcher;
+import org.apache.lucene.search.MatchAllDocsQuery;
+import org.apache.lucene.search.MatchNoDocsQuery;
+import org.apache.lucene.search.Query;
 import org.apache.lucene.search.ScoreDoc;
 import org.apache.lucene.search.Sort;
 import org.apache.lucene.search.TopDocs;
@@ -56,6 +65,7 @@ import org.apache.lucene.search.similarities.BooleanSimilarity;
 import org.apache.lucene.search.similarities.ClassicSimilarity;
 import org.apache.lucene.search.similarities.PerFieldSimilarityWrapper;
 import org.apache.lucene.search.similarities.Similarity;
+import org.apache.lucene.search.similarities.TFIDFSimilarity;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 import org.novasearch.lucene.search.similarities.BM25Similarity;
@@ -63,13 +73,14 @@ import org.novasearch.lucene.search.similarities.BM25Similarity.BM25Model;
 import org.novasearch.lucene.search.similarities.LdpSimilarity;
 import org.novasearch.lucene.search.similarities.LtcSimilarity;
 import org.novasearch.lucene.search.similarities.RobertsonSimilarity;
-import org.reactivestreams.Publisher;
 import org.warp.commonutils.log.Logger;
 import org.warp.commonutils.log.LoggerFactory;
 import reactor.core.publisher.Flux;
 import reactor.core.publisher.Mono;
 import reactor.core.scheduler.Scheduler;
 import reactor.core.scheduler.Schedulers;
+import reactor.util.concurrent.Queues;
+import reactor.util.function.Tuple2;
 
 public class LuceneUtils {
 
@@ -106,6 +117,8 @@ public class LuceneUtils {
 	private static final Similarity luceneLDPNoLengthSimilarityInstance = new LdpSimilarity(0, 0.5f);
 	private static final Similarity luceneBooleanSimilarityInstance = new BooleanSimilarity();
 	private static final Similarity luceneRobertsonSimilarityInstance = new RobertsonSimilarity();
+	// TODO: remove this default page limits and make the limits configurable into QueryParams
+	private static final PageLimits DEFAULT_PAGE_LIMITS = new ExponentialPageLimits();
 
 	@SuppressWarnings("DuplicatedCode")
 	public static Analyzer getAnalyzer(TextFieldsAnalyzer analyzer) {
@@ -178,7 +191,6 @@ public class LuceneUtils {
 	 *
 	 * @return false if the result is not relevant
 	 */
-	@Nullable
 	public static boolean filterTopDoc(float score, Float minCompetitiveScore) {
 		return minCompetitiveScore == null || score >= minCompetitiveScore;
 	}
@@ -220,9 +232,8 @@ public class LuceneUtils {
 	public static <T, U, V> ValueGetter<Entry<T, U>, V> getAsyncDbValueGetterDeep(
 			CompositeSnapshot snapshot,
 			DatabaseMapDictionaryDeep<T, Map<U, V>, DatabaseMapDictionary<U, V>> dictionaryDeep) {
-		return entry -> dictionaryDeep
+		return entry -> LLUtils.usingResource(dictionaryDeep
-				.at(snapshot, entry.getKey())
+				.at(snapshot, entry.getKey()), sub -> sub.getValue(snapshot, entry.getValue()), true);
-				.flatMap(sub -> sub.getValue(snapshot, entry.getValue()).doAfterTerminate(sub::release));
 	}
 
 	public static PerFieldAnalyzerWrapper toPerFieldAnalyzerWrapper(IndicizerAnalyzers indicizerAnalyzers) {
@@ -315,7 +326,7 @@ public class LuceneUtils {
 
 			assert i > 0 : "FileChannel.read with non zero-length bb.remaining() must always read at least one byte (FileChannel is in blocking mode, see spec of ReadableByteChannel)";
 
-			pos += (long)i;
+			pos += i;
 		}
 
 		assert readLength == 0;
@@ -357,34 +368,40 @@ public class LuceneUtils {
 		return new LocalQueryParams(QueryParser.toQuery(queryParams.query()),
 				safeLongToInt(queryParams.offset()),
 				safeLongToInt(queryParams.limit()),
+				DEFAULT_PAGE_LIMITS,
 				queryParams.minCompetitiveScore().getNullable(),
 				QueryParser.toSort(queryParams.sort()),
 				QueryParser.toScoreMode(queryParams.scoreMode())
 		);
 	}
 
-	public static Flux<LLKeyScore> convertHits(Flux<ScoreDoc> hits,
+	public static Flux<LLKeyScore> convertHits(Flux<ScoreDoc> hitsFlux,
-			IndexSearchers indexSearchers,
+			List<IndexSearcher> indexSearchers,
 			String keyFieldName,
-			Scheduler scheduler,
 			boolean preserveOrder) {
-
-		return hits.transform(hitsFlux -> {
 		if (preserveOrder) {
 			return hitsFlux
-						.publishOn(scheduler)
+					.publishOn(Schedulers.boundedElastic())
 					.mapNotNull(hit -> mapHitBlocking(hit, indexSearchers, keyFieldName));
 		} else {
+			// Compute parallelism
+			var availableProcessors = Runtime.getRuntime().availableProcessors();
+			var min = Queues.XS_BUFFER_SIZE;
+			var maxParallelGroups = Math.max(availableProcessors, min);
+
 			return hitsFlux
-						.publishOn(scheduler)
+					.groupBy(hit -> hit.shardIndex % maxParallelGroups) // Max n groups
-						.mapNotNull(hit -> mapHitBlocking(hit, indexSearchers, keyFieldName));
+					.flatMap(shardHits -> shardHits
+									.publishOn(Schedulers.boundedElastic())
+									.mapNotNull(hit -> mapHitBlocking(hit, indexSearchers, keyFieldName)),
+							maxParallelGroups // Max n concurrency. Concurrency must be >= total groups count
+					);
 		}
-		});
 	}
 
 	@Nullable
 	private static LLKeyScore mapHitBlocking(ScoreDoc hit,
-			IndexSearchers indexSearchers,
+			List<IndexSearcher> indexSearchers,
 			String keyFieldName) {
 		if (Schedulers.isInNonBlockingThread()) {
 			throw new UnsupportedOperationException("Called mapHitBlocking in a nonblocking thread");
@@ -392,7 +409,10 @@ public class LuceneUtils {
 		int shardDocId = hit.doc;
 		int shardIndex = hit.shardIndex;
 		float score = hit.score;
-		var indexSearcher = indexSearchers.shard(shardIndex);
+		if (shardIndex == -1 && indexSearchers.size() == 1) {
+			shardIndex = 0;
+		}
+		var indexSearcher = indexSearchers.get(shardIndex);
 		try {
 			String collectedDoc = keyOfTopDoc(shardDocId, indexSearcher.getIndexReader(), keyFieldName);
 			return new LLKeyScore(shardDocId, score, collectedDoc);
@@ -508,4 +528,77 @@ public class LuceneUtils {
 				true
 		);
 	}
+
+	public static Mono<LocalQueryParams> getMoreLikeThisQuery(
+			List<LLIndexSearcher> indexSearchers,
+			LocalQueryParams localQueryParams,
+			Analyzer analyzer,
+			Similarity similarity,
+			Flux<Tuple2<String, Set<String>>> mltDocumentFieldsFlux) {
+		Query luceneAdditionalQuery;
+		try {
+			luceneAdditionalQuery = localQueryParams.query();
+		} catch (Exception e) {
+			return Mono.error(e);
+		}
+		return mltDocumentFieldsFlux
+				.collectMap(Tuple2::getT1, Tuple2::getT2, HashMap::new)
+				.flatMap(mltDocumentFields -> Mono.fromCallable(() -> {
+					mltDocumentFields.entrySet().removeIf(entry -> entry.getValue().isEmpty());
+					if (mltDocumentFields.isEmpty()) {
+						return new LocalQueryParams(new MatchNoDocsQuery(),
+								localQueryParams.offset(),
+								localQueryParams.limit(),
+								DEFAULT_PAGE_LIMITS,
+								localQueryParams.minCompetitiveScore(),
+								localQueryParams.sort(),
+								localQueryParams.scoreMode()
+						);
+					}
+					MultiMoreLikeThis mlt;
+					if (indexSearchers.size() == 1) {
+						mlt = new MultiMoreLikeThis(indexSearchers.get(0).getIndexReader(), null);
+					} else {
+						IndexReader[] indexReaders = new IndexReader[indexSearchers.size()];
+						for (int i = 0, size = indexSearchers.size(); i < size; i++) {
+							indexReaders[i] = indexSearchers.get(i).getIndexReader();
+						}
+						mlt = new MultiMoreLikeThis(indexReaders, null);
+					}
+					mlt.setAnalyzer(analyzer);
+					mlt.setFieldNames(mltDocumentFields.keySet().toArray(String[]::new));
+					mlt.setMinTermFreq(1);
+					mlt.setMinDocFreq(3);
+					mlt.setMaxDocFreqPct(20);
+					mlt.setBoost(localQueryParams.scoreMode().needsScores());
+					mlt.setStopWords(EnglishItalianStopFilter.getStopWordsString());
+					if (similarity instanceof TFIDFSimilarity tfidfSimilarity) {
+						mlt.setSimilarity(tfidfSimilarity);
+					} else {
+						mlt.setSimilarity(new ClassicSimilarity());
+					}
+
+					// Get the reference docId and apply it to MoreLikeThis, to generate the query
+					@SuppressWarnings({"unchecked", "rawtypes"})
+					var mltQuery = mlt.like((Map) mltDocumentFields);
+					Query luceneQuery;
+					if (!(luceneAdditionalQuery instanceof MatchAllDocsQuery)) {
+						luceneQuery = new BooleanQuery.Builder()
+								.add(mltQuery, Occur.MUST)
+								.add(new ConstantScoreQuery(luceneAdditionalQuery), Occur.MUST)
+								.build();
+					} else {
+						luceneQuery = mltQuery;
+					}
+
+					return new LocalQueryParams(luceneQuery,
+							localQueryParams.offset(),
+							localQueryParams.limit(),
+							DEFAULT_PAGE_LIMITS,
+							localQueryParams.minCompetitiveScore(),
+							localQueryParams.sort(),
+							localQueryParams.scoreMode()
+					);
+				}).subscribeOn(Schedulers.boundedElastic()));
+	}
 }

src/main/java/it/cavallium/dbengine/lucene/searcher/AdaptiveLuceneLocalSearcher.java

@@ -1,40 +1,25 @@
 package it.cavallium.dbengine.lucene.searcher;
 
-import org.apache.lucene.search.IndexSearcher;
+import io.net5.buffer.api.Send;
+import it.cavallium.dbengine.database.disk.LLIndexSearcher;
+import it.cavallium.dbengine.database.disk.LLIndexSearchers;
 import reactor.core.publisher.Mono;
-import reactor.core.scheduler.Scheduler;
-import reactor.core.scheduler.Schedulers;
 
 public class AdaptiveLuceneLocalSearcher implements LuceneLocalSearcher {
 
 	private static final LuceneLocalSearcher localSearcher = new SimpleLuceneLocalSearcher();
 
-	private static final LuceneLocalSearcher unscoredPagedLuceneLocalSearcher = new LocalLuceneWrapper(new UnscoredUnsortedContinuousLuceneMultiSearcher());
-
 	private static final LuceneLocalSearcher countSearcher = new CountLuceneLocalSearcher();
 
 	@Override
-	public Mono<LuceneSearchResult> collect(IndexSearcher indexSearcher,
+	public Mono<Send<LuceneSearchResult>> collect(Mono<Send<LLIndexSearcher>> indexSearcher,
-			Mono<Void> releaseIndexSearcher,
 			LocalQueryParams queryParams,
 			String keyFieldName,
-			Scheduler scheduler) {
+			LLSearchTransformer transformer) {
-		if (Schedulers.isInNonBlockingThread()) {
-			return releaseIndexSearcher
-					.then(Mono.error(() -> new UnsupportedOperationException("Called collect in a nonblocking thread")));
-		}
 		if (queryParams.limit() == 0) {
-			return countSearcher.collect(indexSearcher, releaseIndexSearcher, queryParams, keyFieldName, scheduler);
+			return countSearcher.collect(indexSearcher, queryParams, keyFieldName, transformer);
-		} else if (!queryParams.isScored() && queryParams.offset() == 0 && queryParams.limit() >= 2147483630
-				&& !queryParams.isSorted()) {
-			return unscoredPagedLuceneLocalSearcher.collect(indexSearcher,
-					releaseIndexSearcher,
-					queryParams,
-					keyFieldName,
-					scheduler
-			);
 		} else {
-			return localSearcher.collect(indexSearcher, releaseIndexSearcher, queryParams, keyFieldName, scheduler);
+			return localSearcher.collect(indexSearcher, queryParams, keyFieldName, transformer);
 		}
 	}
 }

src/main/java/it/cavallium/dbengine/lucene/searcher/AdaptiveLuceneMultiSearcher.java

@@ -1,27 +1,33 @@
 package it.cavallium.dbengine.lucene.searcher;
 
+import io.net5.buffer.api.Send;
+import it.cavallium.dbengine.database.disk.LLIndexSearcher;
+import it.cavallium.dbengine.database.disk.LLIndexSearchers;
+import reactor.core.publisher.Flux;
 import reactor.core.publisher.Mono;
 
 public class AdaptiveLuceneMultiSearcher implements LuceneMultiSearcher {
 
-	private static final LuceneMultiSearcher scoredLuceneMultiSearcher = new ScoredLuceneMultiSearcher();
+	private static final LuceneMultiSearcher countLuceneMultiSearcher
+			= new SimpleUnsortedUnscoredLuceneMultiSearcher(new CountLuceneLocalSearcher());
 
-	private static final LuceneMultiSearcher unscoredPagedLuceneMultiSearcher = new UnscoredPagedLuceneMultiSearcher();
+	private static final LuceneMultiSearcher scoredSimpleLuceneShardSearcher
+			= new ScoredSimpleLuceneShardSearcher();
 
-	private static final LuceneMultiSearcher unscoredIterableLuceneMultiSearcher = new UnscoredUnsortedContinuousLuceneMultiSearcher();
+	private static final LuceneMultiSearcher unscoredPagedLuceneMultiSearcher
-
+			= new SimpleUnsortedUnscoredLuceneMultiSearcher(new SimpleLuceneLocalSearcher());
-	private static final LuceneMultiSearcher countLuceneMultiSearcher = new CountLuceneMultiSearcher();
 
 	@Override
-	public Mono<LuceneShardSearcher> createShardSearcher(LocalQueryParams queryParams) {
+	public Mono<Send<LuceneSearchResult>> collectMulti(Mono<Send<LLIndexSearchers>> indexSearchersMono,
-		if (queryParams.limit() <= 0) {
+			LocalQueryParams queryParams,
-			return countLuceneMultiSearcher.createShardSearcher(queryParams);
+			String keyFieldName,
-		} else if (queryParams.isScored()) {
+			LLSearchTransformer transformer) {
-			return scoredLuceneMultiSearcher.createShardSearcher(queryParams);
+		if (queryParams.limit() == 0) {
-		} else if (queryParams.offset() == 0 && queryParams.limit() >= 2147483630 && !queryParams.isSorted()) {
+			return countLuceneMultiSearcher.collectMulti(indexSearchersMono, queryParams, keyFieldName, transformer);
-			return unscoredIterableLuceneMultiSearcher.createShardSearcher(queryParams);
+		} else if (queryParams.isSorted() || queryParams.isScored()) {
+			return scoredSimpleLuceneShardSearcher.collectMulti(indexSearchersMono, queryParams, keyFieldName, transformer);
 		} else {
-			return unscoredPagedLuceneMultiSearcher.createShardSearcher(queryParams);
+			return unscoredPagedLuceneMultiSearcher.collectMulti(indexSearchersMono, queryParams, keyFieldName, transformer);
 		}
 	}
 }

src/main/java/it/cavallium/dbengine/lucene/searcher/CountLuceneLocalSearcher.java

@@ -1,28 +1,32 @@
 package it.cavallium.dbengine.lucene.searcher;
 
-import it.cavallium.dbengine.client.query.QueryParser;
+import io.net5.buffer.api.Send;
-import it.cavallium.dbengine.client.query.current.data.QueryParams;
 import it.cavallium.dbengine.client.query.current.data.TotalHitsCount;
-import org.apache.lucene.search.IndexSearcher;
+import it.cavallium.dbengine.database.LLUtils;
+import it.cavallium.dbengine.database.disk.LLIndexSearcher;
 import reactor.core.publisher.Flux;
 import reactor.core.publisher.Mono;
-import reactor.core.scheduler.Scheduler;
 import reactor.core.scheduler.Schedulers;
 
 public class CountLuceneLocalSearcher implements LuceneLocalSearcher {
 
 	@Override
-	public Mono<LuceneSearchResult> collect(IndexSearcher indexSearcher, Mono<Void> releaseIndexSearcher,
+	public Mono<Send<LuceneSearchResult>> collect(Mono<Send<LLIndexSearcher>> indexSearcherMono,
-			LocalQueryParams queryParams, String keyFieldName, Scheduler scheduler) {
+			LocalQueryParams queryParams,
-		return Mono.fromCallable(() -> {
+			String keyFieldName,
-			if (Schedulers.isInNonBlockingThread()) {
+			LLSearchTransformer transformer) {
-				throw new UnsupportedOperationException("Called collect in a nonblocking thread");
+		return Mono
+				.usingWhen(
+						indexSearcherMono,
+						indexSearcher -> Mono.fromCallable(() -> {
+							try (var is = indexSearcher.receive()) {
+								LLUtils.ensureBlocking();
+								return is.getIndexSearcher().count(queryParams.query());
 							}
-			//noinspection BlockingMethodInNonBlockingContext
+						}).subscribeOn(Schedulers.boundedElastic()),
-			return new LuceneSearchResult(TotalHitsCount.of(indexSearcher.count(queryParams.query()), true),
+						is -> Mono.empty()
-					Flux.empty(),
+				)
-					releaseIndexSearcher
+				.map(count -> new LuceneSearchResult(TotalHitsCount.of(count, true), Flux.empty(), drop -> {}).send())
-			);
+				.doOnDiscard(Send.class, Send::close);
-		}).subscribeOn(scheduler);
 	}
 }

src/main/java/it/cavallium/dbengine/lucene/searcher/CountLuceneMultiSearcher.java

@@ -1,55 +0,0 @@
-package it.cavallium.dbengine.lucene.searcher;
-
-import it.cavallium.dbengine.client.query.QueryParser;
-import it.cavallium.dbengine.client.query.current.data.QueryParams;
-import it.cavallium.dbengine.client.query.current.data.TotalHitsCount;
-import java.util.concurrent.ConcurrentLinkedQueue;
-import java.util.concurrent.atomic.AtomicBoolean;
-import java.util.concurrent.atomic.AtomicLong;
-import org.apache.lucene.search.IndexSearcher;
-import org.apache.lucene.search.Query;
-import reactor.core.publisher.Flux;
-import reactor.core.publisher.Mono;
-import reactor.core.scheduler.Scheduler;
-import reactor.core.scheduler.Schedulers;
-
-public class CountLuceneMultiSearcher implements LuceneMultiSearcher {
-
-	@Override
-	public Mono<LuceneShardSearcher> createShardSearcher(LocalQueryParams queryParams) {
-		return Mono
-				.fromCallable(() -> {
-					AtomicLong totalHits = new AtomicLong(0);
-					ConcurrentLinkedQueue<Mono<Void>> release = new ConcurrentLinkedQueue<>();
-					return new LuceneShardSearcher() {
-						@Override
-						public Mono<Void> searchOn(IndexSearcher indexSearcher,
-								Mono<Void> releaseIndexSearcher,
-								LocalQueryParams queryParams,
-								Scheduler scheduler) {
-							return Mono
-									.<Void>fromCallable(() -> {
-										//noinspection BlockingMethodInNonBlockingContext
-										totalHits.addAndGet(indexSearcher.count(queryParams.query()));
-										release.add(releaseIndexSearcher);
-										return null;
-									})
-									.subscribeOn(scheduler);
-						}
-
-						@Override
-						public Mono<LuceneSearchResult> collect(LocalQueryParams queryParams, String keyFieldName, Scheduler scheduler) {
-							return Mono.fromCallable(() -> {
-								if (Schedulers.isInNonBlockingThread()) {
-									throw new UnsupportedOperationException("Called collect in a nonblocking thread");
-								}
-								return new LuceneSearchResult(TotalHitsCount.of(totalHits.get(), true),
-										Flux.empty(),
-										Mono.when(release)
-								);
-							}).subscribeOn(scheduler);
-						}
-					};
-				});
-	}
-}

src/main/java/it/cavallium/dbengine/lucene/searcher/CurrentPageInfo.java

@@ -8,17 +8,6 @@ import org.jetbrains.annotations.Nullable;
 
 record CurrentPageInfo(@Nullable ScoreDoc last, long remainingLimit, int pageIndex) {
 
-	private static final int MAX_ITEMS_PER_PAGE = 500;
-
 	public static final Comparator<ScoreDoc> TIE_BREAKER = Comparator.comparingInt((d) -> d.shardIndex);
 	public static final CurrentPageInfo EMPTY_STATUS = new CurrentPageInfo(null, 0, 0);
-
-	int currentPageLimit() {
-		if (pageIndex >= 10) { // safety
-			return MAX_ITEMS_PER_PAGE;
-		}
-		var min = Math.min(MAX_ITEMS_PER_PAGE, LuceneUtils.safeLongToInt(pageIndex * (0b1L << pageIndex)));
-		assert min > 0;
-		return min;
-	}
 }

src/main/java/it/cavallium/dbengine/lucene/searcher/ExponentialPageLimits.java

@@ -0,0 +1,47 @@
+package it.cavallium.dbengine.lucene.searcher;
+
+import it.cavallium.dbengine.lucene.LuceneUtils;
+
+/**
+ * <pre>y = 2 ^ (x + pageIndexOffset) + firstPageLimit</pre>
+ */
+public class ExponentialPageLimits implements PageLimits {
+
+	private static final int DEFAULT_PAGE_INDEX_OFFSET = 0;
+
+	private final int pageIndexOffset;
+	private final int firstPageLimit;
+	private final int maxItemsPerPage;
+
+	public ExponentialPageLimits() {
+		this(DEFAULT_PAGE_INDEX_OFFSET);
+	}
+
+	public ExponentialPageLimits(int pageIndexOffset) {
+		this(pageIndexOffset, DEFAULT_MIN_ITEMS_PER_PAGE);
+	}
+
+	public ExponentialPageLimits(int pageIndexOffset, int firstPageLimit) {
+		this(pageIndexOffset, firstPageLimit, DEFAULT_MAX_ITEMS_PER_PAGE);
+	}
+
+	public ExponentialPageLimits(int pageIndexOffset, int firstPageLimit, int maxItemsPerPage) {
+		this.pageIndexOffset = pageIndexOffset;
+		this.firstPageLimit = firstPageLimit;
+		this.maxItemsPerPage = maxItemsPerPage;
+	}
+
+	@Override
+	public int getPageLimit(int pageIndex) {
+		var offsetedIndex = pageIndex + pageIndexOffset;
+		var power = 0b1L << offsetedIndex;
+
+		if (offsetedIndex >= 30) { // safety
+			return maxItemsPerPage;
+		}
+
+		var min = Math.max(firstPageLimit, Math.min(maxItemsPerPage, firstPageLimit + power));
+		assert min > 0;
+		return LuceneUtils.safeLongToInt(min);
+	}
+}

src/main/java/it/cavallium/dbengine/lucene/searcher/FirstPageResults.java

@@ -0,0 +1,8 @@
+package it.cavallium.dbengine.lucene.searcher;
+
+import it.cavallium.dbengine.client.query.current.data.TotalHitsCount;
+import it.cavallium.dbengine.database.LLKeyScore;
+import reactor.core.publisher.Flux;
+
+record FirstPageResults(TotalHitsCount totalHitsCount, Flux<LLKeyScore> firstPageHitsFlux,
+												CurrentPageInfo nextPageInfo) {}

src/main/java/it/cavallium/dbengine/lucene/searcher/IndexSearchers.java

@@ -1,27 +0,0 @@
-package it.cavallium.dbengine.lucene.searcher;
-
-import java.util.List;
-import org.apache.lucene.search.IndexSearcher;
-
-public interface IndexSearchers {
-
-	static IndexSearchers of(List<IndexSearcher> indexSearchers) {
-		return shardIndex -> {
-			if (shardIndex < 0) {
-				throw new IndexOutOfBoundsException("Shard index " + shardIndex + " is invalid");
-			}
-			return indexSearchers.get(shardIndex);
-		};
-	}
-
-	static IndexSearchers unsharded(IndexSearcher indexSearcher) {
-		return shardIndex -> {
-			if (shardIndex != -1) {
-				throw new IndexOutOfBoundsException("Shard index " + shardIndex + " is invalid, this is a unsharded index");
-			}
-			return indexSearcher;
-		};
-	}
-
-	IndexSearcher shard(int shardIndex);
-}

src/main/java/it/cavallium/dbengine/lucene/searcher/LLSearchTransformer.java

@@ -0,0 +1,17 @@
+package it.cavallium.dbengine.lucene.searcher;
+
+import it.cavallium.dbengine.database.disk.LLIndexSearcher;
+import java.util.List;
+import org.apache.lucene.index.IndexReader;
+import reactor.core.publisher.Mono;
+
+public interface LLSearchTransformer {
+
+	LLSearchTransformer NO_TRANSFORMATION = queryParamsMono -> queryParamsMono
+			.map(TransformerInput::queryParams);
+
+	record TransformerInput(List<LLIndexSearcher> indexSearchers,
+													LocalQueryParams queryParams) {}
+
+	Mono<LocalQueryParams> transform(Mono<TransformerInput> inputMono);
+}

src/main/java/it/cavallium/dbengine/lucene/searcher/LinearPageLimits.java

@@ -0,0 +1,40 @@
+package it.cavallium.dbengine.lucene.searcher;
+
+import it.cavallium.dbengine.lucene.LuceneUtils;
+
+/**
+ * <pre>y = (x * factor) + firstPageLimit</pre>
+ */
+public class LinearPageLimits implements PageLimits {
+
+	private static final double DEFAULT_FACTOR = 0.5d;
+
+	private final double factor;
+	private final double firstPageLimit;
+	private final double maxItemsPerPage;
+
+	public LinearPageLimits() {
+		this(DEFAULT_FACTOR, DEFAULT_MIN_ITEMS_PER_PAGE);
+	}
+
+	public LinearPageLimits(double factor) {
+		this(factor, DEFAULT_MIN_ITEMS_PER_PAGE);
+	}
+
+	public LinearPageLimits(double factor, int firstPageLimit) {
+		this(factor, firstPageLimit, DEFAULT_MAX_ITEMS_PER_PAGE);
+	}
+
+	public LinearPageLimits(double factor, int firstPageLimit, int maxItemsPerPage) {
+		this.factor = factor;
+		this.firstPageLimit = firstPageLimit;
+		this.maxItemsPerPage = maxItemsPerPage;
+	}
+
+	@Override
+	public int getPageLimit(int pageIndex) {
+		double min = Math.min(maxItemsPerPage, firstPageLimit + (pageIndex * factor));
+		assert min > 0d;
+		return (int) min;
+	}
+}

src/main/java/it/cavallium/dbengine/lucene/searcher/LocalLuceneWrapper.java

@@ -1,28 +0,0 @@
-package it.cavallium.dbengine.lucene.searcher;
-
-import org.apache.lucene.search.IndexSearcher;
-import reactor.core.publisher.Mono;
-import reactor.core.scheduler.Scheduler;
-
-public class LocalLuceneWrapper implements LuceneLocalSearcher {
-
-	private final LuceneMultiSearcher luceneMultiSearcher;
-
-	public LocalLuceneWrapper(LuceneMultiSearcher luceneMultiSearcher) {
-		this.luceneMultiSearcher = luceneMultiSearcher;
-	}
-
-	@Override
-	public Mono<LuceneSearchResult> collect(IndexSearcher indexSearcher,
-			Mono<Void> releaseIndexSearcher,
-			LocalQueryParams queryParams,
-			String keyFieldName,
-			Scheduler scheduler) {
-		var shardSearcher = luceneMultiSearcher.createShardSearcher(queryParams);
-		return shardSearcher
-				.flatMap(luceneShardSearcher -> luceneShardSearcher
-						.searchOn(indexSearcher, releaseIndexSearcher, queryParams, scheduler)
-						.then(luceneShardSearcher.collect(queryParams, keyFieldName, scheduler))
-				);
-	}
-}

src/main/java/it/cavallium/dbengine/lucene/searcher/LocalQueryParams.java

@@ -6,7 +6,7 @@ import org.apache.lucene.search.Sort;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
-public record LocalQueryParams(@NotNull Query query, int offset, int limit,
+public record LocalQueryParams(@NotNull Query query, int offset, int limit, @NotNull PageLimits pageLimits,
 															 @Nullable Float minCompetitiveScore, @Nullable Sort sort,
 															 @NotNull ScoreMode scoreMode) {
 

src/main/java/it/cavallium/dbengine/lucene/searcher/LuceneLocalSearcher.java

@@ -1,21 +1,19 @@
 package it.cavallium.dbengine.lucene.searcher;
 
-import it.cavallium.dbengine.client.query.current.data.QueryParams;
+import io.net5.buffer.api.Send;
-import org.apache.lucene.search.IndexSearcher;
+import it.cavallium.dbengine.database.disk.LLIndexSearcher;
 import reactor.core.publisher.Mono;
-import reactor.core.scheduler.Scheduler;
 
 public interface LuceneLocalSearcher {
 
 	/**
-	 * @param indexSearcher Lucene index searcher
+	 * @param indexSearcherMono Lucene index searcher
 	 * @param queryParams       the query parameters
 	 * @param keyFieldName      the name of the key field
-	 * @param scheduler     a blocking scheduler
+	 * @param transformer       the search query transformer
 	 */
-	Mono<LuceneSearchResult> collect(IndexSearcher indexSearcher,
+	Mono<Send<LuceneSearchResult>> collect(Mono<Send<LLIndexSearcher>> indexSearcherMono,
-			Mono<Void> releaseIndexSearcher,
 			LocalQueryParams queryParams,
 			String keyFieldName,
-			Scheduler scheduler);
+			LLSearchTransformer transformer);
 }

src/main/java/it/cavallium/dbengine/lucene/searcher/LuceneMultiSearcher.java

@@ -1,28 +1,36 @@
 package it.cavallium.dbengine.lucene.searcher;
 
-import it.cavallium.dbengine.client.query.current.data.QueryParams;
+import io.net5.buffer.api.Send;
-import it.cavallium.dbengine.database.LLKeyScore;
+import it.cavallium.dbengine.database.disk.LLIndexSearcher;
-import it.cavallium.dbengine.lucene.LuceneUtils;
+import it.cavallium.dbengine.database.disk.LLIndexSearchers;
-import java.util.ArrayList;
-import java.util.List;
-import org.apache.lucene.search.IndexSearcher;
-import org.apache.lucene.search.Query;
-import org.apache.lucene.search.ScoreDoc;
-import org.apache.lucene.search.ScoreMode;
-import org.apache.lucene.search.Sort;
-import org.jetbrains.annotations.Nullable;
-import org.warp.commonutils.log.Logger;
-import org.warp.commonutils.log.LoggerFactory;
 import reactor.core.publisher.Flux;
 import reactor.core.publisher.Mono;
-import reactor.core.scheduler.Scheduler;
 
-public interface LuceneMultiSearcher {
+public interface LuceneMultiSearcher extends LuceneLocalSearcher {
 
 	/**
-	 * Do a lucene query, receiving the single results using a consumer
+	 * @param indexSearchersMono Lucene index searcher
 	 * @param queryParams        the query parameters
+	 * @param keyFieldName       the name of the key field
+	 * @param transformer        the search query transformer
 	 */
-	Mono<LuceneShardSearcher> createShardSearcher(LocalQueryParams queryParams);
+	Mono<Send<LuceneSearchResult>> collectMulti(Mono<Send<LLIndexSearchers>> indexSearchersMono,
+			LocalQueryParams queryParams,
+			String keyFieldName,
+			LLSearchTransformer transformer);
 
+	/**
+	 * @param indexSearcherMono Lucene index searcher
+	 * @param queryParams       the query parameters
+	 * @param keyFieldName      the name of the key field
+	 * @param transformer       the search query transformer
+	 */
+	@Override
+	default Mono<Send<LuceneSearchResult>> collect(Mono<Send<LLIndexSearcher>> indexSearcherMono,
+			LocalQueryParams queryParams,
+			String keyFieldName,
+			LLSearchTransformer transformer) {
+		var searchers = indexSearcherMono.map(a -> LLIndexSearchers.unsharded(a).send());
+		return this.collectMulti(searchers, queryParams, keyFieldName, transformer);
+	}
 }

src/main/java/it/cavallium/dbengine/lucene/searcher/LuceneSearchResult.java

@@ -1,7 +1,12 @@
 package it.cavallium.dbengine.lucene.searcher;
 
+import io.net5.buffer.api.Drop;
+import io.net5.buffer.api.Owned;
+import io.net5.buffer.api.internal.ResourceSupport;
 import it.cavallium.dbengine.client.query.current.data.TotalHitsCount;
 import it.cavallium.dbengine.database.LLKeyScore;
+import it.cavallium.dbengine.database.LLSearchResultShard;
+import it.cavallium.dbengine.database.LiveResourceSupport;
 import it.cavallium.dbengine.database.disk.LLLocalKeyValueDatabase;
 import java.io.IOException;
 import java.util.Objects;
@@ -10,37 +15,31 @@ import org.warp.commonutils.log.LoggerFactory;
 import reactor.core.publisher.Flux;
 import reactor.core.publisher.Mono;
 
-public final class LuceneSearchResult {
+public final class LuceneSearchResult extends LiveResourceSupport<LuceneSearchResult, LuceneSearchResult> {
 
 	private static final Logger logger = LoggerFactory.getLogger(LuceneSearchResult.class);
 
-	private volatile boolean releaseCalled;
+	private TotalHitsCount totalHitsCount;
+	private Flux<LLKeyScore> results;
 
-	private final TotalHitsCount totalHitsCount;
+	public LuceneSearchResult(TotalHitsCount totalHitsCount, Flux<LLKeyScore> results, Drop<LuceneSearchResult> drop) {
-	private final Flux<LLKeyScore> results;
+		super(drop);
-	private final Mono<Void> release;
-
-	public LuceneSearchResult(TotalHitsCount totalHitsCount, Flux<LLKeyScore> results, Mono<Void> release) {
 		this.totalHitsCount = totalHitsCount;
 		this.results = results;
-		this.release = Mono.fromRunnable(() -> {
-			if (releaseCalled) {
-				logger.warn(this.getClass().getName() + "::release has been called twice!");
-			}
-			releaseCalled = true;
-		}).then(release);
 	}
 
 	public TotalHitsCount totalHitsCount() {
+		if (!isOwned()) {
+			throw attachTrace(new IllegalStateException("LuceneSearchResult must be owned to be used"));
+		}
 		return totalHitsCount;
 	}
 
 	public Flux<LLKeyScore> results() {
-		return results;
+		if (!isOwned()) {
+			throw attachTrace(new IllegalStateException("LuceneSearchResult must be owned to be used"));
 		}
-
+		return results;
-	public Mono<Void> release() {
-		return release;
 	}
 
 	@Override
@@ -63,13 +62,21 @@ public final class LuceneSearchResult {
 		return "LuceneSearchResult[" + "totalHitsCount=" + totalHitsCount + ", " + "results=" + results + ']';
 	}
 
-	@SuppressWarnings("deprecation")
 	@Override
-	protected void finalize() throws Throwable {
+	protected RuntimeException createResourceClosedException() {
-		if (!releaseCalled) {
+		return new IllegalStateException("Closed");
-			logger.warn(this.getClass().getName() + "::release has not been called before class finalization!");
 	}
-		super.finalize();
+
+	@Override
+	protected Owned<LuceneSearchResult> prepareSend() {
+		var totalHitsCount = this.totalHitsCount;
+		var results = this.results;
+		return drop -> new LuceneSearchResult(totalHitsCount, results, drop);
+	}
+
+	protected void makeInaccessible() {
+		this.totalHitsCount = null;
+		this.results = null;
 	}
 
 }

src/main/java/it/cavallium/dbengine/lucene/searcher/LuceneShardSearcher.java

@@ -1,26 +0,0 @@
-package it.cavallium.dbengine.lucene.searcher;
-
-import it.cavallium.dbengine.client.query.current.data.QueryParams;
-import org.apache.lucene.search.IndexSearcher;
-import reactor.core.publisher.Mono;
-import reactor.core.scheduler.Scheduler;
-
-public interface LuceneShardSearcher {
-
-	/**
-	 * @param indexSearcher the index searcher, which contains all the lucene data
-	 * @param queryParams the query parameters
-	 * @param scheduler a blocking scheduler
-	 */
-	Mono<Void> searchOn(IndexSearcher indexSearcher,
-			Mono<Void> indexSearcherRelease,
-			LocalQueryParams queryParams,
-			Scheduler scheduler);
-
-	/**
-	 * @param queryParams the query parameters
-	 * @param keyFieldName the name of the key field
-	 * @param collectorScheduler a blocking scheduler
-	 */
-	Mono<LuceneSearchResult> collect(LocalQueryParams queryParams, String keyFieldName, Scheduler collectorScheduler);
-}

src/main/java/it/cavallium/dbengine/lucene/searcher/PageData.java

@@ -0,0 +1,5 @@
+package it.cavallium.dbengine.lucene.searcher;
+
+import org.apache.lucene.search.TopDocs;
+
+record PageData(TopDocs topDocs, CurrentPageInfo nextPageInfo) {}

src/main/java/it/cavallium/dbengine/lucene/searcher/PageLimits.java

@@ -0,0 +1,11 @@
+package it.cavallium.dbengine.lucene.searcher;
+
+import it.cavallium.dbengine.lucene.LuceneUtils;
+
+public interface PageLimits {
+
+	int DEFAULT_MIN_ITEMS_PER_PAGE = 10;
+	int DEFAULT_MAX_ITEMS_PER_PAGE = 250;
+
+	int getPageLimit(int pageIndex);
+}

src/main/java/it/cavallium/dbengine/lucene/searcher/PaginationInfo.java

@@ -3,7 +3,7 @@ package it.cavallium.dbengine.lucene.searcher;
 import java.util.Comparator;
 import org.apache.lucene.search.ScoreDoc;
 
-public record PaginationInfo(long totalLimit, long firstPageOffset, long firstPageLimit, boolean forceSinglePage) {
+public record PaginationInfo(long totalLimit, long firstPageOffset, PageLimits pageLimits, boolean forceSinglePage) {
 
 	public static final int MAX_SINGLE_SEARCH_LIMIT = 256;
 	public static final int FIRST_PAGE_LIMIT = 10;

src/main/java/it/cavallium/dbengine/lucene/searcher/ScoredLuceneMultiSearcher.java

@@ -1,38 +0,0 @@
-package it.cavallium.dbengine.lucene.searcher;
-
-import static it.cavallium.dbengine.lucene.searcher.PaginationInfo.FIRST_PAGE_LIMIT;
-import static it.cavallium.dbengine.lucene.searcher.PaginationInfo.MAX_SINGLE_SEARCH_LIMIT;
-
-import it.cavallium.dbengine.lucene.LuceneUtils;
-import org.apache.lucene.search.CollectorManager;
-import org.apache.lucene.search.Sort;
-import org.apache.lucene.search.TopDocs;
-import org.apache.lucene.search.TopFieldCollector;
-import org.apache.lucene.search.TopFieldDocs;
-import reactor.core.publisher.Mono;
-
-public class ScoredLuceneMultiSearcher implements LuceneMultiSearcher {
-
-	@Override
-	public Mono<LuceneShardSearcher> createShardSearcher(LocalQueryParams queryParams) {
-		return Mono
-				.fromCallable(() -> {
-					Sort luceneSort = queryParams.sort();
-					if (luceneSort == null) {
-						luceneSort = Sort.RELEVANCE;
-					}
-					PaginationInfo paginationInfo;
-					if (queryParams.limit() <= MAX_SINGLE_SEARCH_LIMIT) {
-						paginationInfo = new PaginationInfo(queryParams.limit(), queryParams.offset(), queryParams.limit(), true);
-					} else {
-						paginationInfo = new PaginationInfo(queryParams.limit(), queryParams.offset(), FIRST_PAGE_LIMIT, false);
-					}
-					CollectorManager<TopFieldCollector, TopDocs> sharedManager = new ScoringShardsCollectorManager(luceneSort,
-							LuceneUtils.safeLongToInt(paginationInfo.firstPageOffset() + paginationInfo.firstPageLimit()),
-							null, LuceneUtils.totalHitsThreshold(), LuceneUtils.safeLongToInt(paginationInfo.firstPageOffset()),
-							LuceneUtils.safeLongToInt(paginationInfo.firstPageLimit()));
-					return new ScoredSimpleLuceneShardSearcher(sharedManager, queryParams.query(), paginationInfo);
-				});
-	}
-
-}

src/main/java/it/cavallium/dbengine/lucene/searcher/ScoredSimpleLuceneShardSearcher.java

@@ -1,168 +1,200 @@
 package it.cavallium.dbengine.lucene.searcher;
 
-import static it.cavallium.dbengine.lucene.searcher.CurrentPageInfo.EMPTY_STATUS;
+import static it.cavallium.dbengine.lucene.searcher.PaginationInfo.FIRST_PAGE_LIMIT;
-import static it.cavallium.dbengine.lucene.searcher.CurrentPageInfo.TIE_BREAKER;
+import static it.cavallium.dbengine.lucene.searcher.PaginationInfo.MAX_SINGLE_SEARCH_LIMIT;
 
+import io.net5.buffer.api.Send;
 import it.cavallium.dbengine.database.LLKeyScore;
+import it.cavallium.dbengine.database.LLUtils;
+import it.cavallium.dbengine.database.disk.LLIndexSearcher;
+import it.cavallium.dbengine.database.disk.LLIndexSearchers;
+import it.cavallium.dbengine.database.disk.LLLocalGroupedReactiveRocksIterator;
 import it.cavallium.dbengine.lucene.LuceneUtils;
-import it.unimi.dsi.fastutil.objects.ObjectArrayList;
-import java.io.IOException;
-import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
 import java.util.Objects;
-import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.concurrent.atomic.AtomicReference;
-import java.util.stream.Collectors;
-import org.apache.lucene.search.CollectorManager;
 import org.apache.lucene.search.FieldDoc;
 import org.apache.lucene.search.IndexSearcher;
-import org.apache.lucene.search.Query;
-import org.apache.lucene.search.ScoreDoc;
 import org.apache.lucene.search.Sort;
-import org.apache.lucene.search.TopDocs;
+import org.warp.commonutils.log.Logger;
-import org.apache.lucene.search.TopFieldCollector;
+import org.warp.commonutils.log.LoggerFactory;
-import org.apache.lucene.search.TopFieldDocs;
 import reactor.core.publisher.Flux;
 import reactor.core.publisher.Mono;
-import reactor.core.publisher.Sinks;
-import reactor.core.publisher.Sinks.Empty;
-import reactor.core.scheduler.Scheduler;
 import reactor.core.scheduler.Schedulers;
 
-class ScoredSimpleLuceneShardSearcher implements LuceneShardSearcher {
+public class ScoredSimpleLuceneShardSearcher implements LuceneMultiSearcher {
 
-	private final Object lock = new Object();
+	protected static final Logger logger = LoggerFactory.getLogger(ScoredSimpleLuceneShardSearcher.class);
-	private final List<IndexSearcher> indexSearchersArray = new ArrayList<>();
-	private final List<Mono<Void>> indexSearcherReleasersArray = new ArrayList<>();
-	private final List<TopFieldCollector> collectors = new ArrayList<>();
-	private final CollectorManager<TopFieldCollector, TopDocs> firstPageSharedManager;
-	private final Query luceneQuery;
-	private final PaginationInfo paginationInfo;
 
-	public ScoredSimpleLuceneShardSearcher(CollectorManager<TopFieldCollector, TopDocs> firstPageSharedManager,
+	public ScoredSimpleLuceneShardSearcher() {
-			Query luceneQuery, PaginationInfo paginationInfo) {
-		this.firstPageSharedManager = firstPageSharedManager;
-		this.luceneQuery = luceneQuery;
-		this.paginationInfo = paginationInfo;
 	}
 
 	@Override
-	public Mono<Void> searchOn(IndexSearcher indexSearcher,
+	public Mono<Send<LuceneSearchResult>> collectMulti(Mono<Send<LLIndexSearchers>> indexSearchersMono,
-			Mono<Void> releaseIndexSearcher,
 			LocalQueryParams queryParams,
-			Scheduler scheduler) {
+			String keyFieldName,
-		return Mono.<Void>fromCallable(() -> {
+			LLSearchTransformer transformer) {
-			if (Schedulers.isInNonBlockingThread()) {
+		Objects.requireNonNull(queryParams.scoreMode(), "ScoreMode must not be null");
-				throw new UnsupportedOperationException("Called searchOn in a nonblocking thread");
+		PaginationInfo paginationInfo = getPaginationInfo(queryParams);
-			}
+
-			TopFieldCollector collector;
+		return LLUtils.usingSendResource(indexSearchersMono, indexSearchers -> this
-			synchronized (lock) {
+						// Search first page results
-				//noinspection BlockingMethodInNonBlockingContext
+						.searchFirstPage(indexSearchers.shards(), queryParams, paginationInfo)
-				collector = firstPageSharedManager.newCollector();
+						// Compute the results of the first page
-				indexSearchersArray.add(indexSearcher);
+						.transform(firstPageTopDocsMono -> this.computeFirstPageResults(firstPageTopDocsMono, indexSearchers,
-				indexSearcherReleasersArray.add(releaseIndexSearcher);
+								keyFieldName, queryParams))
-				collectors.add(collector);
+						// Compute other results
-			}
+						.map(firstResult -> this.computeOtherResults(firstResult, indexSearchers.shards(), queryParams, keyFieldName, indexSearchers::close))
-			//noinspection BlockingMethodInNonBlockingContext
+						// Ensure that one LuceneSearchResult is always returned
-			indexSearcher.search(luceneQuery, collector);
+						.single(),
-			return null;
+				false);
-		}).subscribeOn(scheduler);
 	}
 
-	@Override
+	private Sort getSort(LocalQueryParams queryParams) {
-	public Mono<LuceneSearchResult> collect(LocalQueryParams queryParams, String keyFieldName, Scheduler collectorScheduler) {
-		if (Schedulers.isInNonBlockingThread()) {
-			return Mono.error(() -> new UnsupportedOperationException("Called collect in a nonblocking thread"));
-		}
-		if (!queryParams.isScored()) {
-			return Mono.error(() -> new UnsupportedOperationException("Can't execute an unscored query"
-					+ " with a scored lucene shard searcher"));
-		}
-		return Mono
-				.fromCallable(() -> {
-					TopDocs result;
-					Mono<Void> release;
-					synchronized (lock) {
-						//noinspection BlockingMethodInNonBlockingContext
-						result = firstPageSharedManager.reduce(collectors);
-						release = Mono.when(indexSearcherReleasersArray);
-					}
-					IndexSearchers indexSearchers;
-					synchronized (lock) {
-						indexSearchers = IndexSearchers.of(indexSearchersArray);
-					}
-					Flux<LLKeyScore> firstPageHits = LuceneUtils
-							.convertHits(Flux.fromArray(result.scoreDocs), indexSearchers, keyFieldName, collectorScheduler, true);
-
-					Flux<LLKeyScore> nextHits;
-					nextHits = Flux
-							.<TopDocs, CurrentPageInfo>generate(
-									() -> new CurrentPageInfo(LuceneUtils.getLastFieldDoc(result.scoreDocs),
-											paginationInfo.totalLimit() - paginationInfo.firstPageLimit(), 1),
-									(s, emitter) -> {
-										if (Schedulers.isInNonBlockingThread()) {
-											throw new UnsupportedOperationException("Called collect in a nonblocking thread");
-										}
-
-										if (s.last() != null && s.remainingLimit() > 0) {
 		Sort luceneSort = queryParams.sort();
 		if (luceneSort == null) {
 			luceneSort = Sort.RELEVANCE;
 		}
-											CollectorManager<TopFieldCollector, TopDocs> sharedManager
+		return luceneSort;
-													= new ScoringShardsCollectorManager(luceneSort, s.currentPageLimit(),
-													(FieldDoc) s.last(), LuceneUtils.totalHitsThreshold(), 0, s.currentPageLimit());
-
-											try {
-												var collectors = new ObjectArrayList<TopFieldCollector>(indexSearchersArray.size());
-												for (IndexSearcher indexSearcher : indexSearchersArray) {
-													//noinspection BlockingMethodInNonBlockingContext
-													TopFieldCollector collector = sharedManager.newCollector();
-													//noinspection BlockingMethodInNonBlockingContext
-													indexSearcher.search(luceneQuery, collector);
-
-													collectors.add(collector);
 	}
 
-												//noinspection BlockingMethodInNonBlockingContext
+	/**
+	 * Get the pagination info
+	 */
+	private PaginationInfo getPaginationInfo(LocalQueryParams queryParams) {
+		if (queryParams.limit() <= MAX_SINGLE_SEARCH_LIMIT) {
+			return new PaginationInfo(queryParams.limit(), queryParams.offset(), queryParams.pageLimits(), true);
+		} else {
+			return new PaginationInfo(queryParams.limit(), queryParams.offset(), queryParams.pageLimits(), false);
+		}
+	}
+
+	/**
+	 * Search effectively the raw results of the first page
+	 */
+	private Mono<PageData> searchFirstPage(Iterable<IndexSearcher> indexSearchers,
+			LocalQueryParams queryParams,
+			PaginationInfo paginationInfo) {
+		var limit = paginationInfo.totalLimit();
+		var pageLimits = paginationInfo.pageLimits();
+		var pagination = !paginationInfo.forceSinglePage();
+		var resultsOffset = LuceneUtils.safeLongToInt(paginationInfo.firstPageOffset());
+		return Mono
+				.fromSupplier(() -> new CurrentPageInfo(null, limit, 0))
+				.flatMap(s -> this.searchPage(queryParams, indexSearchers, pagination, pageLimits, resultsOffset, s));
+	}
+
+	/**
+	 * Compute the results of the first page, extracting useful data
+	 */
+	private Mono<FirstPageResults> computeFirstPageResults(Mono<PageData> firstPageDataMono,
+			LLIndexSearchers indexSearchers,
+			String keyFieldName,
+			LocalQueryParams queryParams) {
+		return firstPageDataMono.map(firstPageData -> {
+			var totalHitsCount = LuceneUtils.convertTotalHitsCount(firstPageData.topDocs().totalHits);
+			var scoreDocs = firstPageData.topDocs().scoreDocs;
+			assert LLUtils.isSet(scoreDocs);
+
+			Flux<LLKeyScore> firstPageHitsFlux = LuceneUtils.convertHits(Flux.fromArray(scoreDocs),
+							indexSearchers.shards(), keyFieldName, true)
+					.take(queryParams.limit(), true);
+
+			CurrentPageInfo nextPageInfo = firstPageData.nextPageInfo();
+
+			return new FirstPageResults(totalHitsCount, firstPageHitsFlux, nextPageInfo);
+		});
+	}
+
+	private Send<LuceneSearchResult> computeOtherResults(FirstPageResults firstResult,
+			List<IndexSearcher> indexSearchers,
+			LocalQueryParams queryParams,
+			String keyFieldName,
+			Runnable drop) {
+		var totalHitsCount = firstResult.totalHitsCount();
+		var firstPageHitsFlux = firstResult.firstPageHitsFlux();
+		var secondPageInfo = firstResult.nextPageInfo();
+
+		Flux<LLKeyScore> nextHitsFlux = searchOtherPages(indexSearchers, queryParams, keyFieldName, secondPageInfo);
+
+		Flux<LLKeyScore> combinedFlux = firstPageHitsFlux.concatWith(nextHitsFlux);
+		return new LuceneSearchResult(totalHitsCount, combinedFlux, d -> drop.run()).send();
+	}
+
+	/**
+	 * Search effectively the merged raw results of the next pages
+	 */
+	private Flux<LLKeyScore> searchOtherPages(List<IndexSearcher> indexSearchers,
+			LocalQueryParams queryParams, String keyFieldName, CurrentPageInfo secondPageInfo) {
+		return Flux
+				.defer(() -> {
+					AtomicReference<CurrentPageInfo> currentPageInfoRef = new AtomicReference<>(secondPageInfo);
+					return Mono
+							.fromSupplier(currentPageInfoRef::get)
+							.doOnNext(s -> logger.debug("Current page info: {}", s))
+							.flatMap(currentPageInfo -> this.searchPage(queryParams, indexSearchers, true,
+									queryParams.pageLimits(), 0, currentPageInfo))
+							.doOnNext(s -> logger.debug("Next page info: {}", s.nextPageInfo()))
+							.doOnNext(s -> currentPageInfoRef.set(s.nextPageInfo()))
+							.repeatWhen(s -> s.takeWhile(n -> n > 0));
+				})
+				.subscribeOn(Schedulers.boundedElastic())
+				.map(PageData::topDocs)
+				.flatMapIterable(topDocs -> Arrays.asList(topDocs.scoreDocs))
+				.transform(topFieldDocFlux -> LuceneUtils.convertHits(topFieldDocFlux, indexSearchers,
+						keyFieldName, true));
+	}
+
+	/**
+	 *
+	 * @param resultsOffset offset of the resulting topDocs. Useful if you want to
+	 *                       skip the first n results in the first page
+	 */
+	private Mono<PageData> searchPage(LocalQueryParams queryParams,
+			Iterable<IndexSearcher> indexSearchers,
+			boolean allowPagination,
+			PageLimits pageLimits,
+			int resultsOffset,
+			CurrentPageInfo s) {
+		return Mono
+				.fromCallable(() -> {
+					LLUtils.ensureBlocking();
+					if (resultsOffset < 0) {
+						throw new IndexOutOfBoundsException(resultsOffset);
+					}
+					if ((s.pageIndex() == 0 || s.last() != null) && s.remainingLimit() > 0) {
+						var sort = getSort(queryParams);
+						var pageLimit = pageLimits.getPageLimit(s.pageIndex());
+						var after = (FieldDoc) s.last();
+						var totalHitsThreshold = LuceneUtils.totalHitsThreshold();
+						return new ScoringShardsCollectorManager(sort, pageLimit, after, totalHitsThreshold,
+								resultsOffset);
+					} else {
+						return null;
+					}
+				})
+				.flatMap(sharedManager -> Flux
+						.fromIterable(indexSearchers)
+						.flatMap(shard -> Mono.fromCallable(() -> {
+							var collector = sharedManager.newCollector();
+							shard.search(queryParams.query(), collector);
+							return collector;
+						}))
+						.collectList()
+						.flatMap(collectors -> Mono.fromCallable(() -> {
 							var pageTopDocs = sharedManager.reduce(collectors);
-												var pageLastDoc = LuceneUtils.getLastFieldDoc(pageTopDocs.scoreDocs);
+							var pageLastDoc = LuceneUtils.getLastScoreDoc(pageTopDocs.scoreDocs);
-												emitter.next(pageTopDocs);
+							long nextRemainingLimit;
-
+							if (allowPagination) {
-												s = new CurrentPageInfo(pageLastDoc, s.remainingLimit() - s.currentPageLimit(),
+								nextRemainingLimit = s.remainingLimit() - pageLimits.getPageLimit(s.pageIndex());
-														s.pageIndex() + 1);
-											} catch (IOException ex) {
-												emitter.error(ex);
-												s = EMPTY_STATUS;
-											}
 							} else {
-											emitter.complete();
+								nextRemainingLimit = 0L;
-											s = EMPTY_STATUS;
 							}
-										return s;
+							var nextPageIndex = s.pageIndex() + 1;
-							})
+							var nextPageInfo = new CurrentPageInfo(pageLastDoc, nextRemainingLimit, nextPageIndex);
-							.subscribeOn(collectorScheduler)
+							return new PageData(pageTopDocs, nextPageInfo);
-							.transform(flux -> {
+						}))
-								if (paginationInfo.forceSinglePage()
-										|| paginationInfo.totalLimit() - paginationInfo.firstPageLimit() <= 0) {
-									return Flux.empty();
-								} else {
-									return flux;
-								}
-							})
-							.flatMapIterable(topFieldDoc -> Arrays.asList(topFieldDoc.scoreDocs))
-							.transform(scoreDocs -> LuceneUtils.convertHits(scoreDocs,
-									indexSearchers, keyFieldName, collectorScheduler, true));
-
-					return new LuceneSearchResult(LuceneUtils.convertTotalHitsCount(result.totalHits),
-							firstPageHits
-									.concatWith(nextHits),
-									//.transform(flux -> LuceneUtils.filterTopDoc(flux, queryParams)),
-							release
 				);
-				})
-				.subscribeOn(collectorScheduler);
 	}
-
 }

src/main/java/it/cavallium/dbengine/lucene/searcher/ScoringShardsCollectorManager.java

@@ -2,6 +2,7 @@ package it.cavallium.dbengine.lucene.searcher;
 
 import static it.cavallium.dbengine.lucene.searcher.CurrentPageInfo.TIE_BREAKER;
 
+import it.cavallium.dbengine.database.LLUtils;
 import it.cavallium.dbengine.lucene.LuceneUtils;
 import java.io.IOException;
 import java.util.Collection;
@@ -34,6 +35,14 @@ public class ScoringShardsCollectorManager implements CollectorManager<TopFieldC
 		this(sort, numHits, after, totalHitsThreshold, (Integer) startN, (Integer) topN);
 	}
 
+	public ScoringShardsCollectorManager(final Sort sort,
+			final int numHits,
+			final FieldDoc after,
+			final int totalHitsThreshold,
+			int startN) {
+		this(sort, numHits, after, totalHitsThreshold, (Integer) startN, (Integer) 2147483630);
+	}
+
 	public ScoringShardsCollectorManager(final Sort sort,
 			final int numHits,
 			final FieldDoc after,
@@ -52,7 +61,13 @@ public class ScoringShardsCollectorManager implements CollectorManager<TopFieldC
 		this.after = after;
 		this.totalHitsThreshold = totalHitsThreshold;
 		this.startN = startN;
+		if (topN != null && startN != null && (long) topN + (long) startN > 2147483630) {
+			this.topN	= 2147483630 - startN;
+		} else if (topN != null && topN > 2147483630) {
+			this.topN = 2147483630;
+		} else {
 			this.topN = topN;
+		}
 		this.sharedCollectorManager = TopFieldCollector.createSharedManager(sort, numHits, after, totalHitsThreshold);
 	}
 

src/main/java/it/cavallium/dbengine/lucene/searcher/SimpleLuceneLocalSearcher.java

@@ -4,10 +4,16 @@ import static it.cavallium.dbengine.lucene.searcher.CurrentPageInfo.EMPTY_STATUS
 import static it.cavallium.dbengine.lucene.searcher.PaginationInfo.FIRST_PAGE_LIMIT;
 import static it.cavallium.dbengine.lucene.searcher.PaginationInfo.MAX_SINGLE_SEARCH_LIMIT;
 
+import io.net5.buffer.api.Send;
 import it.cavallium.dbengine.database.LLKeyScore;
+import it.cavallium.dbengine.database.LLUtils;
+import it.cavallium.dbengine.database.disk.LLIndexSearcher;
+import it.cavallium.dbengine.database.disk.LLIndexSearchers;
+import it.cavallium.dbengine.database.disk.LLIndexSearchers.UnshardedIndexSearchers;
 import it.cavallium.dbengine.lucene.LuceneUtils;
 import java.io.IOException;
 import java.util.Arrays;
+import java.util.List;
 import java.util.Objects;
 import org.apache.lucene.search.IndexSearcher;
 import org.apache.lucene.search.ScoreDoc;
@@ -15,105 +21,164 @@ import org.apache.lucene.search.TopDocs;
 import org.apache.lucene.search.TopDocsCollector;
 import reactor.core.publisher.Flux;
 import reactor.core.publisher.Mono;
-import reactor.core.scheduler.Scheduler;
+import reactor.core.publisher.SynchronousSink;
 import reactor.core.scheduler.Schedulers;
 
 public class SimpleLuceneLocalSearcher implements LuceneLocalSearcher {
 
 	@Override
-	public Mono<LuceneSearchResult> collect(IndexSearcher indexSearcher,
+	public Mono<Send<LuceneSearchResult>> collect(Mono<Send<LLIndexSearcher>> indexSearcherMono,
-			Mono<Void> releaseIndexSearcher,
 			LocalQueryParams queryParams,
 			String keyFieldName,
-			Scheduler scheduler) {
+			LLSearchTransformer transformer) {
-		return Mono
+
-				.fromCallable(() -> {
-					if (Schedulers.isInNonBlockingThread()) {
-						throw new UnsupportedOperationException("Called collect in a nonblocking thread");
-					}
 		Objects.requireNonNull(queryParams.scoreMode(), "ScoreMode must not be null");
-					PaginationInfo paginationInfo;
+		PaginationInfo paginationInfo = getPaginationInfo(queryParams);
+
+		var indexSearchersMono = indexSearcherMono.map(LLIndexSearchers::unsharded);
+
+		return LLUtils.usingResource(indexSearchersMono, indexSearchers -> this
+				// Search first page results
+				.searchFirstPage(indexSearchers.shards(), queryParams, paginationInfo)
+				// Compute the results of the first page
+				.transform(firstPageTopDocsMono -> this.computeFirstPageResults(firstPageTopDocsMono, indexSearchers.shards(),
+						keyFieldName, queryParams))
+				// Compute other results
+				.transform(firstResult -> this.computeOtherResults(firstResult, indexSearchers.shards(), queryParams,
+						keyFieldName, indexSearchers::close))
+				// Ensure that one LuceneSearchResult is always returned
+				.single(),
+				false);
+	}
+
+	/**
+	 * Get the pagination info
+	 */
+	private PaginationInfo getPaginationInfo(LocalQueryParams queryParams) {
 		if (queryParams.limit() <= MAX_SINGLE_SEARCH_LIMIT) {
-						paginationInfo = new PaginationInfo(queryParams.limit(), queryParams.offset(), queryParams.limit(), true);
+			return new PaginationInfo(queryParams.limit(), queryParams.offset(), queryParams.pageLimits(), true);
 		} else {
-						paginationInfo = new PaginationInfo(queryParams.limit(), queryParams.offset(), FIRST_PAGE_LIMIT, false);
+			return new PaginationInfo(queryParams.limit(), queryParams.offset(), queryParams.pageLimits(), false);
 		}
-					TopDocs firstPageTopDocs;
-					{
-						TopDocsCollector<ScoreDoc> firstPageCollector = TopDocsSearcher.getTopDocsCollector(
-								queryParams.sort(),
-								LuceneUtils.safeLongToInt(paginationInfo.firstPageOffset() + paginationInfo.firstPageLimit()),
-								null,
-								LuceneUtils.totalHitsThreshold(),
-								!paginationInfo.forceSinglePage(),
-								queryParams.isScored());
-						//noinspection BlockingMethodInNonBlockingContext
-						indexSearcher.search(queryParams.query(), firstPageCollector);
-						firstPageTopDocs = firstPageCollector.topDocs(LuceneUtils.safeLongToInt(paginationInfo.firstPageOffset()),
-								LuceneUtils.safeLongToInt(paginationInfo.firstPageLimit())
-						);
 	}
-					Flux<LLKeyScore> firstPageMono = LuceneUtils
+
-							.convertHits(Flux.fromArray(firstPageTopDocs.scoreDocs), IndexSearchers.unsharded(indexSearcher),
+	/**
-									keyFieldName, scheduler, true)
+	 * Search effectively the raw results of the first page
+	 */
+	private Mono<PageData> searchFirstPage(List<IndexSearcher> indexSearchers,
+			LocalQueryParams queryParams,
+			PaginationInfo paginationInfo) {
+		var limit = paginationInfo.totalLimit();
+		var pagination = !paginationInfo.forceSinglePage();
+		var resultsOffset = LuceneUtils.safeLongToInt(paginationInfo.firstPageOffset());
+		return Mono
+				.fromSupplier(() -> new CurrentPageInfo(null, limit, 0))
+				.handle((s, sink) -> this.searchPageSync(queryParams, indexSearchers, pagination, resultsOffset, s, sink));
+	}
+
+	/**
+	 * Compute the results of the first page, extracting useful data
+	 */
+	private Mono<FirstPageResults> computeFirstPageResults(Mono<PageData> firstPageDataMono,
+			List<IndexSearcher> indexSearchers,
+			String keyFieldName,
+			LocalQueryParams queryParams) {
+		return firstPageDataMono.map(firstPageData -> {
+			var totalHitsCount = LuceneUtils.convertTotalHitsCount(firstPageData.topDocs().totalHits);
+			var scoreDocs = firstPageData.topDocs().scoreDocs;
+			assert LLUtils.isSet(scoreDocs);
+
+			Flux<LLKeyScore> firstPageHitsFlux = LuceneUtils.convertHits(Flux.fromArray(scoreDocs),
+							indexSearchers, keyFieldName, true)
 					.take(queryParams.limit(), true);
 
+			CurrentPageInfo nextPageInfo = firstPageData.nextPageInfo();
 
-					Flux<LLKeyScore> nextHits;
+			return new FirstPageResults(totalHitsCount, firstPageHitsFlux, nextPageInfo);
-					if (paginationInfo.forceSinglePage() || paginationInfo.totalLimit() - paginationInfo.firstPageLimit() <= 0) {
+		});
-						nextHits = null;
-					} else {
-						nextHits = Flux.defer(() -> Flux
-								.<TopDocs, CurrentPageInfo>generate(
-										() -> new CurrentPageInfo(LuceneUtils.getLastScoreDoc(firstPageTopDocs.scoreDocs), paginationInfo.totalLimit() - paginationInfo.firstPageLimit(), 1),
-										(s, sink) -> {
-											if (Schedulers.isInNonBlockingThread()) {
-												throw new UnsupportedOperationException("Called collect in a nonblocking thread");
 	}
-											if (s.last() != null && s.remainingLimit() > 0) {
+
+	private Mono<Send<LuceneSearchResult>> computeOtherResults(Mono<FirstPageResults> firstResultMono,
+			List<IndexSearcher> indexSearchers,
+			LocalQueryParams queryParams,
+			String keyFieldName,
+			Runnable drop) {
+		return firstResultMono.map(firstResult -> {
+			var totalHitsCount = firstResult.totalHitsCount();
+			var firstPageHitsFlux = firstResult.firstPageHitsFlux();
+			var secondPageInfo = firstResult.nextPageInfo();
+
+			Flux<LLKeyScore> nextHitsFlux = searchOtherPages(indexSearchers, queryParams, keyFieldName, secondPageInfo);
+
+			Flux<LLKeyScore> combinedFlux = firstPageHitsFlux.concatWith(nextHitsFlux);
+			return new LuceneSearchResult(totalHitsCount, combinedFlux, d -> drop.run()).send();
+		});
+	}
+
+	/**
+	 * Search effectively the merged raw results of the next pages
+	 */
+	private Flux<LLKeyScore> searchOtherPages(List<IndexSearcher> indexSearchers,
+			LocalQueryParams queryParams, String keyFieldName, CurrentPageInfo secondPageInfo) {
+		return Flux
+				.<PageData, CurrentPageInfo>generate(
+						() -> secondPageInfo,
+						(s, sink) -> searchPageSync(queryParams, indexSearchers, true, 0, s, sink),
+						s -> {}
+				)
+				.subscribeOn(Schedulers.boundedElastic())
+				.map(PageData::topDocs)
+				.flatMapIterable(topDocs -> Arrays.asList(topDocs.scoreDocs))
+				.transform(topFieldDocFlux -> LuceneUtils.convertHits(topFieldDocFlux, indexSearchers,
+						keyFieldName, true));
+	}
+
+	/**
+	 *
+	 * @param resultsOffset offset of the resulting topDocs. Useful if you want to
+	 *                       skip the first n results in the first page
+	 */
+	private CurrentPageInfo searchPageSync(LocalQueryParams queryParams,
+			List<IndexSearcher> indexSearchers,
+			boolean allowPagination,
+			int resultsOffset,
+			CurrentPageInfo s,
+			SynchronousSink<PageData> sink) {
+		LLUtils.ensureBlocking();
+		if (resultsOffset < 0) {
+			throw new IndexOutOfBoundsException(resultsOffset);
+		}
+		var currentPageLimit = queryParams.pageLimits().getPageLimit(s.pageIndex());
+		if ((s.pageIndex() == 0 || s.last() != null) && s.remainingLimit() > 0) {
 			TopDocs pageTopDocs;
 			try {
 				TopDocsCollector<ScoreDoc> collector = TopDocsSearcher.getTopDocsCollector(queryParams.sort(),
-															s.currentPageLimit(), s.last(), LuceneUtils.totalHitsThreshold(), true,
+						currentPageLimit, s.last(), LuceneUtils.totalHitsThreshold(),
-															queryParams.isScored());
+						allowPagination, queryParams.isScored());
-													//noinspection BlockingMethodInNonBlockingContext
+				indexSearchers.get(0).search(queryParams.query(), collector);
-													indexSearcher.search(queryParams.query(), collector);
+				if (resultsOffset > 0) {
+					pageTopDocs = collector.topDocs(resultsOffset, currentPageLimit);
+				} else {
 					pageTopDocs = collector.topDocs();
+				}
 			} catch (IOException e) {
 				sink.error(e);
 				return EMPTY_STATUS;
 			}
 			var pageLastDoc = LuceneUtils.getLastScoreDoc(pageTopDocs.scoreDocs);
-												sink.next(pageTopDocs);
+			long nextRemainingLimit;
-												return new CurrentPageInfo(pageLastDoc, s.remainingLimit() - s.currentPageLimit(), s.pageIndex() + 1);
+			if (allowPagination) {
+				nextRemainingLimit = s.remainingLimit() - currentPageLimit;
+			} else {
+				nextRemainingLimit = 0L;
+			}
+			var nextPageIndex = s.pageIndex() + 1;
+			var nextPageInfo = new CurrentPageInfo(pageLastDoc, nextRemainingLimit, nextPageIndex);
+			sink.next(new PageData(pageTopDocs, nextPageInfo));
+			return nextPageInfo;
 		} else {
 			sink.complete();
 			return EMPTY_STATUS;
 		}
-										},
-										s -> {}
-								)
-								.subscribeOn(scheduler)
-								.flatMapIterable(topDocs -> Arrays.asList(topDocs.scoreDocs))
-								.transform(topFieldDocFlux -> LuceneUtils.convertHits(topFieldDocFlux,
-										IndexSearchers.unsharded(indexSearcher), keyFieldName, scheduler, true))
-							);
-					}
-
-					Flux<LLKeyScore> combinedFlux;
-
-					if (nextHits != null) {
-						combinedFlux = firstPageMono
-								.concatWith(nextHits);
-					} else {
-						combinedFlux = firstPageMono;
-					}
-
-					return new LuceneSearchResult(LuceneUtils.convertTotalHitsCount(firstPageTopDocs.totalHits), combinedFlux,
-							//.transform(flux -> LuceneUtils.filterTopDoc(flux, queryParams)),
-							releaseIndexSearcher
-					);
-				})
-				.subscribeOn(scheduler);
 	}
 }

src/main/java/it/cavallium/dbengine/lucene/searcher/SimpleUnsortedUnscoredLuceneMultiSearcher.java

@@ -0,0 +1,90 @@
+package it.cavallium.dbengine.lucene.searcher;
+
+import io.net5.buffer.api.Send;
+import it.cavallium.dbengine.client.query.current.data.TotalHitsCount;
+import it.cavallium.dbengine.database.LLKeyScore;
+import it.cavallium.dbengine.database.LLUtils;
+import it.cavallium.dbengine.database.disk.LLIndexSearcher;
+import it.cavallium.dbengine.database.disk.LLIndexSearchers;
+import java.util.ArrayList;
+import java.util.List;
+import reactor.core.publisher.Flux;
+import reactor.core.publisher.Mono;
+
+public class SimpleUnsortedUnscoredLuceneMultiSearcher implements LuceneMultiSearcher {
+
+	private final LuceneLocalSearcher localSearcher;
+
+	public SimpleUnsortedUnscoredLuceneMultiSearcher(LuceneLocalSearcher localSearcher) {
+		this.localSearcher = localSearcher;
+	}
+
+	@Override
+	public Mono<Send<LuceneSearchResult>> collectMulti(Mono<Send<LLIndexSearchers>> indexSearchersMono,
+			LocalQueryParams queryParams,
+			String keyFieldName,
+			LLSearchTransformer transformer) {
+		var indexSearchersSendResource = Mono
+				.fromRunnable(() -> {
+					LLUtils.ensureBlocking();
+					if (queryParams.isSorted() && queryParams.limit() > 0) {
+						throw new UnsupportedOperationException("Sorted queries are not supported"
+								+ " by SimpleUnsortedUnscoredLuceneMultiSearcher");
+					}
+					if (queryParams.isScored() && queryParams.limit() > 0) {
+						throw new UnsupportedOperationException("Scored queries are not supported"
+								+ " by SimpleUnsortedUnscoredLuceneMultiSearcher");
+					}
+				})
+				.then(indexSearchersMono);
+		var localQueryParams = getLocalQueryParams(queryParams);
+
+		return LLUtils.usingSendResource(indexSearchersSendResource,
+				indexSearchers -> Flux
+						.fromIterable(indexSearchers.shards())
+						.flatMap(searcher -> {
+							var llSearcher = Mono.fromCallable(() -> new LLIndexSearcher(searcher, d -> {}).send());
+							return localSearcher.collect(llSearcher, localQueryParams, keyFieldName, transformer);
+						})
+						.collectList()
+						.map(results -> {
+							List<LuceneSearchResult> resultsToDrop = new ArrayList<>(results.size());
+							List<Flux<LLKeyScore>> resultsFluxes = new ArrayList<>(results.size());
+							boolean exactTotalHitsCount = true;
+							long totalHitsCountValue = 0;
+							for (Send<LuceneSearchResult> resultToReceive : results) {
+								LuceneSearchResult result = resultToReceive.receive();
+								resultsToDrop.add(result);
+								resultsFluxes.add(result.results());
+								exactTotalHitsCount &= result.totalHitsCount().exact();
+								totalHitsCountValue += result.totalHitsCount().value();
+							}
+
+							var totalHitsCount = new TotalHitsCount(totalHitsCountValue, exactTotalHitsCount);
+							Flux<LLKeyScore> mergedFluxes = Flux
+									.merge(resultsFluxes)
+									.skip(queryParams.offset())
+									.take(queryParams.limit(), true);
+
+							return new LuceneSearchResult(totalHitsCount, mergedFluxes, d -> {
+								for (LuceneSearchResult luceneSearchResult : resultsToDrop) {
+									luceneSearchResult.close();
+								}
+								indexSearchers.close();
+							}).send();
+						}),
+				false
+		);
+	}
+
+	private LocalQueryParams getLocalQueryParams(LocalQueryParams queryParams) {
+		return new LocalQueryParams(queryParams.query(),
+				0,
+				queryParams.limit(),
+				queryParams.pageLimits(),
+				queryParams.minCompetitiveScore(),
+				queryParams.sort(),
+				queryParams.scoreMode()
+		);
+	}
+}

src/main/java/it/cavallium/dbengine/lucene/searcher/SinglePageLimits.java

@@ -0,0 +1,23 @@
+package it.cavallium.dbengine.lucene.searcher;
+
+public class SinglePageLimits implements PageLimits {
+
+	private final int firstPageLimit;
+
+	public SinglePageLimits() {
+		this(DEFAULT_MIN_ITEMS_PER_PAGE);
+	}
+
+	public SinglePageLimits(int firstPageLimit) {
+		this.firstPageLimit = firstPageLimit;
+	}
+
+	@Override
+	public int getPageLimit(int pageIndex) {
+		if (pageIndex == 0) {
+			return firstPageLimit;
+		} else {
+			return 0;
+		}
+	}
+}

src/main/java/it/cavallium/dbengine/lucene/searcher/UnscoredPagedLuceneMultiSearcher.java

@@ -1,34 +0,0 @@
-package it.cavallium.dbengine.lucene.searcher;
-
-import static it.cavallium.dbengine.lucene.searcher.PaginationInfo.FIRST_PAGE_LIMIT;
-import static it.cavallium.dbengine.lucene.searcher.PaginationInfo.MAX_SINGLE_SEARCH_LIMIT;
-
-import it.cavallium.dbengine.lucene.LuceneUtils;
-import reactor.core.publisher.Mono;
-
-public class UnscoredPagedLuceneMultiSearcher implements LuceneMultiSearcher {
-
-	@Override
-	public Mono<LuceneShardSearcher> createShardSearcher(LocalQueryParams queryParams) {
-		return Mono
-				.fromCallable(() -> {
-					if (queryParams.isScored()) {
-						throw new UnsupportedOperationException("Can't use the unscored searcher to do a scored or sorted query");
-					}
-					PaginationInfo paginationInfo;
-					if (queryParams.limit() <= MAX_SINGLE_SEARCH_LIMIT) {
-						paginationInfo = new PaginationInfo(queryParams.limit(), queryParams.offset(), queryParams.limit(), true);
-					} else {
-						paginationInfo = new PaginationInfo(queryParams.limit(), queryParams.offset(), FIRST_PAGE_LIMIT, false);
-					}
-					UnscoredTopDocsCollectorManager unsortedCollectorManager = new UnscoredTopDocsCollectorManager(() -> TopDocsSearcher.getTopDocsCollector(queryParams.sort(),
-							LuceneUtils.safeLongToInt(paginationInfo.firstPageOffset() + paginationInfo.firstPageLimit()),
-							null,
-							LuceneUtils.totalHitsThreshold(),
-							!paginationInfo.forceSinglePage(),
-							queryParams.isScored()
-					), queryParams.offset(), queryParams.limit(), queryParams.sort());
-					return new UnscoredPagedLuceneShardSearcher(unsortedCollectorManager, queryParams.query(), paginationInfo);
-				});
-	}
-}

src/main/java/it/cavallium/dbengine/lucene/searcher/UnscoredPagedLuceneShardSearcher.java

@@ -1,152 +0,0 @@
-package it.cavallium.dbengine.lucene.searcher;
-
-import static it.cavallium.dbengine.lucene.searcher.CurrentPageInfo.EMPTY_STATUS;
-
-import it.cavallium.dbengine.database.LLKeyScore;
-import it.cavallium.dbengine.lucene.LuceneUtils;
-import it.unimi.dsi.fastutil.objects.ObjectArrayList;
-import java.io.IOException;
-import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.List;
-import java.util.Objects;
-import java.util.stream.Collectors;
-import org.apache.lucene.search.CollectorManager;
-import org.apache.lucene.search.IndexSearcher;
-import org.apache.lucene.search.Query;
-import org.apache.lucene.search.ScoreDoc;
-import org.apache.lucene.search.TopDocs;
-import org.apache.lucene.search.TopDocsCollector;
-import reactor.core.publisher.Flux;
-import reactor.core.publisher.Mono;
-import reactor.core.scheduler.Scheduler;
-import reactor.core.scheduler.Schedulers;
-
-class UnscoredPagedLuceneShardSearcher implements LuceneShardSearcher {
-
-	private final Object lock = new Object();
-	private final List<IndexSearcher> indexSearchersArray = new ArrayList<>();
-	private final List<Mono<Void>> indexSearcherReleasersArray = new ArrayList<>();
-	private final List<TopDocsCollector<ScoreDoc>> collectors = new ArrayList<>();
-	private final CollectorManager<TopDocsCollector<ScoreDoc>, TopDocs> firstPageUnsortedCollectorManager;
-	private final Query luceneQuery;
-	private final PaginationInfo paginationInfo;
-
-	public UnscoredPagedLuceneShardSearcher(
-			CollectorManager<TopDocsCollector<ScoreDoc>, TopDocs> firstPagensortedCollectorManager,
-			Query luceneQuery,
-			PaginationInfo paginationInfo) {
-		this.firstPageUnsortedCollectorManager = firstPagensortedCollectorManager;
-		this.luceneQuery = luceneQuery;
-		this.paginationInfo = paginationInfo;
-	}
-
-	@Override
-	public Mono<Void> searchOn(IndexSearcher indexSearcher,
-			Mono<Void> releaseIndexSearcher,
-			LocalQueryParams queryParams,
-			Scheduler scheduler) {
-		return Mono.<Void>fromCallable(() -> {
-			if (Schedulers.isInNonBlockingThread()) {
-				throw new UnsupportedOperationException("Called searchOn in a nonblocking thread");
-			}
-			TopDocsCollector<ScoreDoc> collector;
-			synchronized (lock) {
-				//noinspection BlockingMethodInNonBlockingContext
-				collector = firstPageUnsortedCollectorManager.newCollector();
-				indexSearchersArray.add(indexSearcher);
-				indexSearcherReleasersArray.add(releaseIndexSearcher);
-				collectors.add(collector);
-			}
-			//noinspection BlockingMethodInNonBlockingContext
-			indexSearcher.search(luceneQuery, collector);
-			return null;
-		}).subscribeOn(scheduler);
-	}
-
-	@Override
-	public Mono<LuceneSearchResult> collect(LocalQueryParams queryParams, String keyFieldName, Scheduler scheduler) {
-		return Mono
-				.fromCallable(() -> {
-					if (Schedulers.isInNonBlockingThread()) {
-						throw new UnsupportedOperationException("Called collect in a nonblocking thread");
-					}
-					TopDocs result;
-					Mono<Void> release;
-					synchronized (lock) {
-						//noinspection BlockingMethodInNonBlockingContext
-						result = firstPageUnsortedCollectorManager.reduce(collectors);
-						release = Mono.when(indexSearcherReleasersArray);
-					}
-					IndexSearchers indexSearchers;
-					synchronized (lock) {
-						indexSearchers = IndexSearchers.of(indexSearchersArray);
-					}
-					Flux<LLKeyScore> firstPageHits = LuceneUtils
-							.convertHits(Flux.fromArray(result.scoreDocs), indexSearchers, keyFieldName, scheduler, false);
-
-					Flux<LLKeyScore> nextHits = Flux
-							.<TopDocs, CurrentPageInfo>generate(
-									() -> new CurrentPageInfo(LuceneUtils.getLastScoreDoc(result.scoreDocs),
-											paginationInfo.totalLimit() - paginationInfo.firstPageLimit(), 1),
-									(s, sink) -> {
-										if (s.last() != null && s.remainingLimit() > 0 && s.currentPageLimit() > 0) {
-											Objects.requireNonNull(queryParams.scoreMode(), "ScoreMode must not be null");
-											Query luceneQuery = queryParams.query();
-											int perShardCollectorLimit = s.currentPageLimit() / indexSearchersArray.size();
-											UnscoredTopDocsCollectorManager currentPageUnsortedCollectorManager
-													= new UnscoredTopDocsCollectorManager(
-															() -> TopDocsSearcher.getTopDocsCollector(queryParams.sort(), perShardCollectorLimit,
-																	s.last(), LuceneUtils.totalHitsThreshold(), true, queryParams.isScored()),
-													0, s.currentPageLimit(), queryParams.sort());
-
-											try {
-												var collectors = new ObjectArrayList<TopDocsCollector<ScoreDoc>>(indexSearchersArray.size());
-												for (IndexSearcher indexSearcher : indexSearchersArray) {
-													//noinspection BlockingMethodInNonBlockingContext
-													var collector = currentPageUnsortedCollectorManager.newCollector();
-													//noinspection BlockingMethodInNonBlockingContext
-													indexSearcher.search(luceneQuery, collector);
-
-													collectors.add(collector);
-												}
-												//noinspection BlockingMethodInNonBlockingContext
-												TopDocs pageTopDocs = currentPageUnsortedCollectorManager.reduce(collectors);
-												var pageLastDoc = LuceneUtils.getLastScoreDoc(pageTopDocs.scoreDocs);
-
-												sink.next(pageTopDocs);
-												return new CurrentPageInfo(pageLastDoc, s.remainingLimit() - s.currentPageLimit(),
-														s.pageIndex() + 1);
-											} catch (IOException ex) {
-												sink.error(ex);
-												return EMPTY_STATUS;
-											}
-										} else {
-											sink.complete();
-											return EMPTY_STATUS;
-										}
-									}
-							)
-							.subscribeOn(scheduler)
-							.flatMapIterable(topDocs -> Arrays.asList(topDocs.scoreDocs))
-							.transform(scoreDocsFlux -> LuceneUtils.convertHits(scoreDocsFlux,
-									indexSearchers, keyFieldName, scheduler, false))
-							.transform(flux -> {
-								if (paginationInfo.forceSinglePage()
-										|| paginationInfo.totalLimit() - paginationInfo.firstPageLimit() <= 0) {
-									return Flux.empty();
-								} else {
-									return flux;
-								}
-							});
-
-					return new LuceneSearchResult(LuceneUtils.convertTotalHitsCount(result.totalHits), firstPageHits
-							.concatWith(nextHits),
-							//.transform(flux -> LuceneUtils.filterTopDoc(flux, queryParams)),
-							release
-					);
-				})
-				.subscribeOn(scheduler);
-		}
-
-}

src/main/java/it/cavallium/dbengine/lucene/searcher/UnscoredTopDocsCollectorManager.java

@@ -1,70 +0,0 @@
-package it.cavallium.dbengine.lucene.searcher;
-
-import static it.cavallium.dbengine.lucene.searcher.CurrentPageInfo.TIE_BREAKER;
-import static it.cavallium.dbengine.lucene.searcher.PaginationInfo.ALLOW_UNSCORED_PAGINATION_MODE;
-
-import it.cavallium.dbengine.lucene.LuceneUtils;
-import java.io.IOException;
-import java.util.Collection;
-import java.util.function.Supplier;
-import org.apache.lucene.search.Collector;
-import org.apache.lucene.search.CollectorManager;
-import org.apache.lucene.search.ScoreDoc;
-import org.apache.lucene.search.Sort;
-import org.apache.lucene.search.TopDocs;
-import org.apache.lucene.search.TopDocsCollector;
-import org.apache.lucene.search.TopFieldDocs;
-import org.jetbrains.annotations.Nullable;
-import reactor.core.scheduler.Schedulers;
-
-public class UnscoredTopDocsCollectorManager implements
-		CollectorManager<TopDocsCollector<ScoreDoc>, TopDocs> {
-
-	private final Supplier<TopDocsCollector<ScoreDoc>> collectorSupplier;
-	private final long offset;
-	private final long limit;
-	private final Sort sort;
-
-	public UnscoredTopDocsCollectorManager(Supplier<TopDocsCollector<ScoreDoc>> collectorSupplier,
-			long offset,
-			long limit,
-			@Nullable Sort sort) {
-		this.collectorSupplier = collectorSupplier;
-		this.offset = offset;
-		this.limit = limit;
-		this.sort = sort;
-	}
-
-	@Override
-	public TopDocsCollector<ScoreDoc> newCollector() throws IOException {
-		return collectorSupplier.get();
-	}
-
-	@Override
-	public TopDocs reduce(Collection<TopDocsCollector<ScoreDoc>> collection) throws IOException {
-		if (Schedulers.isInNonBlockingThread()) {
-			throw new UnsupportedOperationException("Called reduce in a nonblocking thread");
-		}
-		int i = 0;
-		TopDocs[] topDocsArray;
-		if (sort != null) {
-			topDocsArray = new TopFieldDocs[collection.size()];
-		} else {
-			topDocsArray = new TopDocs[collection.size()];
-		}
-		for (TopDocsCollector<? extends ScoreDoc> topDocsCollector : collection) {
-			var topDocs = topDocsCollector.topDocs();
-			for (ScoreDoc scoreDoc : topDocs.scoreDocs) {
-				scoreDoc.shardIndex = i;
-			}
-			topDocsArray[i] = topDocs;
-			i++;
-		}
-		return LuceneUtils.mergeTopDocs(sort,
-				LuceneUtils.safeLongToInt(offset),
-				LuceneUtils.safeLongToInt(limit),
-				topDocsArray,
-				TIE_BREAKER
-		);
-	}
-}

src/main/java/it/cavallium/dbengine/lucene/searcher/UnscoredUnsortedContinuousLuceneMultiSearcher.java

@@ -1,183 +0,0 @@
-package it.cavallium.dbengine.lucene.searcher;
-
-import it.cavallium.dbengine.client.query.current.data.TotalHitsCount;
-import it.cavallium.dbengine.lucene.LuceneUtils;
-import it.unimi.dsi.fastutil.objects.ObjectArrayList;
-import java.io.IOException;
-import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.Collection;
-import java.util.List;
-import java.util.concurrent.atomic.AtomicBoolean;
-import java.util.concurrent.atomic.AtomicInteger;
-import java.util.concurrent.locks.LockSupport;
-import org.apache.lucene.index.LeafReaderContext;
-import org.apache.lucene.search.Collector;
-import org.apache.lucene.search.CollectorManager;
-import org.apache.lucene.search.IndexSearcher;
-import org.apache.lucene.search.ScoreDoc;
-import org.apache.lucene.search.ScoreMode;
-import org.apache.lucene.search.SimpleCollector;
-import reactor.core.publisher.Flux;
-import reactor.core.publisher.Mono;
-import reactor.core.publisher.Sinks;
-import reactor.core.publisher.Sinks.EmitResult;
-import reactor.core.publisher.Sinks.Many;
-import reactor.core.scheduler.Scheduler;
-import reactor.core.scheduler.Schedulers;
-import reactor.util.concurrent.Queues;
-
-public class UnscoredUnsortedContinuousLuceneMultiSearcher implements LuceneMultiSearcher {
-
-	private static final Scheduler UNSCORED_UNSORTED_EXECUTOR = Schedulers.newBoundedElastic(Runtime
-			.getRuntime()
-			.availableProcessors(), Schedulers.DEFAULT_BOUNDED_ELASTIC_QUEUESIZE, "UnscoredUnsortedExecutor");
-
-	@Override
-	public Mono<LuceneShardSearcher> createShardSearcher(LocalQueryParams queryParams) {
-		return Mono
-				.fromCallable(() -> {
-					AtomicBoolean alreadySubscribed = new AtomicBoolean(false);
-					Many<ScoreDoc> scoreDocsSink = Sinks.many().unicast().onBackpressureBuffer();
-					// 1 is the collect phase
-					AtomicInteger remainingCollectors = new AtomicInteger(1);
-
-					if (queryParams.isScored()) {
-						throw new UnsupportedOperationException("Can't use the unscored searcher to do a scored or sorted query");
-					}
-
-					var cm = new CollectorManager<Collector, Void>() {
-
-						class IterableCollector extends SimpleCollector {
-
-							private int shardIndex;
-							private LeafReaderContext context;
-
-							@Override
-							public void collect(int i) {
-								if (Schedulers.isInNonBlockingThread()) {
-									throw new UnsupportedOperationException("Called collect in a nonblocking thread");
-								}
-								var scoreDoc = new ScoreDoc(context.docBase + i, 0, shardIndex);
-								synchronized (scoreDocsSink) {
-									while (scoreDocsSink.tryEmitNext(scoreDoc) == EmitResult.FAIL_OVERFLOW) {
-										LockSupport.parkNanos(10);
-									}
-								}
-							}
-
-							@Override
-							protected void doSetNextReader(LeafReaderContext context) {
-								this.context = context;
-							}
-
-							@Override
-							public ScoreMode scoreMode() {
-								return ScoreMode.COMPLETE_NO_SCORES;
-							}
-
-							public void setShardIndex(int shardIndex) {
-								this.shardIndex = shardIndex;
-							}
-						}
-
-						@Override
-						public IterableCollector newCollector() {
-							return new IterableCollector();
-						}
-
-						@Override
-						public Void reduce(Collection<Collector> collection) {
-							throw new UnsupportedOperationException();
-						}
-					};
-
-					return new LuceneShardSearcher() {
-						private final Object lock = new Object();
-						private final List<IndexSearcher> indexSearchersArray = new ArrayList<>();
-						private final List<Mono<Void>> indexSearcherReleasersArray = new ArrayList<>();
-						@Override
-						public Mono<Void> searchOn(IndexSearcher indexSearcher,
-								Mono<Void> releaseIndexSearcher,
-								LocalQueryParams queryParams,
-								Scheduler scheduler) {
-							return Mono
-									.<Void>fromCallable(() -> {
-										if (Schedulers.isInNonBlockingThread()) {
-											throw new UnsupportedOperationException("Called searchOn in a nonblocking thread");
-										}
-										//noinspection BlockingMethodInNonBlockingContext
-										var collector = cm.newCollector();
-										int collectorShardIndex;
-										synchronized (lock) {
-											collectorShardIndex = indexSearchersArray.size();
-											indexSearchersArray.add(indexSearcher);
-											indexSearcherReleasersArray.add(releaseIndexSearcher);
-										}
-										collector.setShardIndex(collectorShardIndex);
-										remainingCollectors.incrementAndGet();
-										UNSCORED_UNSORTED_EXECUTOR.schedule(() -> {
-											try {
-												indexSearcher.search(queryParams.query(), collector);
-
-												synchronized (scoreDocsSink) {
-													decrementRemainingCollectors(scoreDocsSink, remainingCollectors);
-												}
-											} catch (IOException e) {
-												scoreDocsSink.tryEmitError(e);
-											}
-										});
-										return null;
-									})
-									.subscribeOn(scheduler);
-						}
-
-						@Override
-						public Mono<LuceneSearchResult> collect(LocalQueryParams queryParams,
-								String keyFieldName,
-								Scheduler scheduler) {
-							return Mono
-									.fromCallable(() -> {
-										if (Schedulers.isInNonBlockingThread()) {
-											throw new UnsupportedOperationException("Called collect in a nonblocking thread");
-										}
-										synchronized (scoreDocsSink) {
-											decrementRemainingCollectors(scoreDocsSink, remainingCollectors);
-										}
-
-										if (!alreadySubscribed.compareAndSet(false, true)) {
-											throw new UnsupportedOperationException("Already subscribed!");
-										}
-
-										IndexSearchers indexSearchers;
-										Mono<Void> release;
-										synchronized (lock) {
-											indexSearchers = IndexSearchers.of(indexSearchersArray);
-											release = Mono.when(indexSearcherReleasersArray);
-										}
-
-										AtomicBoolean resultsAlreadySubscribed = new AtomicBoolean(false);
-
-										var scoreDocsFlux = Mono.<Void>fromCallable(() -> {
-											if (!resultsAlreadySubscribed.compareAndSet(false, true)) {
-												throw new UnsupportedOperationException("Already subscribed!");
-											}
-											return null;
-										}).thenMany(scoreDocsSink.asFlux());
-										var resultsFlux = LuceneUtils
-												.convertHits(scoreDocsFlux, indexSearchers, keyFieldName, scheduler, false);
-
-										return new LuceneSearchResult(TotalHitsCount.of(0, false), resultsFlux, release);
-									})
-									.subscribeOn(scheduler);
-						}
-					};
-				});
-	}
-
-	private static void decrementRemainingCollectors(Many<ScoreDoc> scoreDocsSink, AtomicInteger remainingCollectors) {
-		if (remainingCollectors.decrementAndGet() <= 0) {
-			scoreDocsSink.tryEmitComplete();
-		}
-	}
-}

src/main/java/it/cavallium/dbengine/netty/NullableBuffer.java

@@ -0,0 +1,70 @@
+package it.cavallium.dbengine.netty;
+
+import io.net5.buffer.api.Buffer;
+import io.net5.buffer.api.Drop;
+import io.net5.buffer.api.Owned;
+import io.net5.buffer.api.Send;
+import io.net5.buffer.api.internal.ResourceSupport;
+import it.cavallium.dbengine.client.SearchResult;
+import it.cavallium.dbengine.database.LiveResourceSupport;
+import org.jetbrains.annotations.Nullable;
+
+public class NullableBuffer extends LiveResourceSupport<NullableBuffer, NullableBuffer> {
+
+	@Nullable
+	private Buffer buffer;
+
+	public NullableBuffer(@Nullable Buffer buffer, Drop<NullableBuffer> drop) {
+		super(new CloseOnDrop(drop));
+		this.buffer = buffer == null ? null : buffer.send().receive();
+	}
+
+	public NullableBuffer(@Nullable Send<Buffer> buffer, Drop<NullableBuffer> drop) {
+		super(new CloseOnDrop(drop));
+		this.buffer = buffer == null ? null : buffer.receive();
+	}
+
+	@Nullable
+	public Buffer buf() {
+		return buffer;
+	}
+
+	@Nullable
+	public Send<Buffer> sendBuf() {
+		return buffer == null ? null : buffer.send();
+	}
+
+	@Override
+	protected RuntimeException createResourceClosedException() {
+		return new IllegalStateException("Closed");
+	}
+
+	@Override
+	protected Owned<NullableBuffer> prepareSend() {
+		var buffer = this.buffer == null ? null : this.buffer.send();
+		return drop -> new NullableBuffer(buffer, drop);
+	}
+
+	protected void makeInaccessible() {
+		this.buffer = null;
+	}
+
+	private static class CloseOnDrop implements Drop<NullableBuffer> {
+
+		private final Drop<NullableBuffer> delegate;
+
+		public CloseOnDrop(Drop<NullableBuffer> drop) {
+			this.delegate = drop;
+		}
+
+		@Override
+		public void drop(NullableBuffer obj) {
+			if (obj.buffer != null) {
+				if (obj.buffer.isAccessible()) {
+					obj.buffer.close();
+				}
+			}
+			delegate.drop(obj);
+		}
+	}
+}

src/main/java/org/rocksdb/CappedWriteBatch.java

@@ -105,13 +105,13 @@ public class CappedWriteBatch extends WriteBatch {
 		var value = valueToReceive.receive();
 		if (USE_FAST_DIRECT_BUFFERS && isDirect(key) && isDirect(value)) {
 			buffersToRelease.add(value);
-			var keyNioBuffer = LLUtils.convertToDirect(alloc, key.send());
+			var keyNioBuffer = LLUtils.convertToReadableDirect(alloc, key.send());
 			key = keyNioBuffer.buffer().receive();
 			buffersToRelease.add(key);
 			byteBuffersToRelease.add(keyNioBuffer.byteBuffer());
 			assert keyNioBuffer.byteBuffer().isDirect();
 
-			var valueNioBuffer = LLUtils.convertToDirect(alloc, value.send());
+			var valueNioBuffer = LLUtils.convertToReadableDirect(alloc, value.send());
 			value = valueNioBuffer.buffer().receive();
 			buffersToRelease.add(value);
 			byteBuffersToRelease.add(valueNioBuffer.byteBuffer());
@@ -172,7 +172,7 @@ public class CappedWriteBatch extends WriteBatch {
 	public synchronized void delete(ColumnFamilyHandle columnFamilyHandle, Send<Buffer> keyToReceive) throws RocksDBException {
 		var key = keyToReceive.receive();
 		if (USE_FAST_DIRECT_BUFFERS) {
-			var keyNioBuffer = LLUtils.convertToDirect(alloc, key.send());
+			var keyNioBuffer = LLUtils.convertToReadableDirect(alloc, key.send());
 			key = keyNioBuffer.buffer().receive();
 			buffersToRelease.add(key);
 			byteBuffersToRelease.add(keyNioBuffer.byteBuffer());

src/test/java/it/cavallium/dbengine/DbTestUtils.java

@@ -25,11 +25,14 @@ import it.cavallium.dbengine.database.serialization.Serializer;
 import it.cavallium.dbengine.database.serialization.SerializerFixedBinaryLength;
 import java.nio.file.Path;
 import java.util.Map;
+import java.util.Objects;
 import java.util.function.Function;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 import org.reactivestreams.Publisher;
 import reactor.core.publisher.Flux;
 import reactor.core.publisher.Mono;
+import reactor.core.scheduler.Schedulers;
 
 public class DbTestUtils {
 
@@ -40,6 +43,38 @@ public class DbTestUtils {
 		return "0123456789".repeat(1024);
 	}
 
+	public static void run(Flux<?> publisher) {
+		publisher.subscribeOn(Schedulers.immediate()).blockLast();
+	}
+
+	public static void runVoid(Mono<Void> publisher) {
+		publisher.then().subscribeOn(Schedulers.immediate()).block();
+	}
+
+	public static <T> T run(Mono<T> publisher) {
+		return publisher.subscribeOn(Schedulers.immediate()).block();
+	}
+
+	public static <T> T run(boolean shouldFail, Mono<T> publisher) {
+		return publisher.subscribeOn(Schedulers.immediate()).transform(mono -> {
+			if (shouldFail) {
+				return mono.onErrorResume(ex -> Mono.empty());
+			} else {
+				return mono;
+			}
+		}).block();
+	}
+
+	public static void runVoid(boolean shouldFail, Mono<Void> publisher) {
+		publisher.then().subscribeOn(Schedulers.immediate()).transform(mono -> {
+			if (shouldFail) {
+				return mono.onErrorResume(ex -> Mono.empty());
+			} else {
+				return mono;
+			}
+		}).block();
+	}
+
 	public static record TestAllocator(PooledBufferAllocator allocator) {}
 
 	public static TestAllocator newAllocator() {
@@ -98,7 +133,7 @@ public class DbTestUtils {
 		if (!MemorySegmentUtils.isSupported()) {
 			System.err.println("Warning! Foreign Memory Access API is not available!"
 					+ " Netty direct buffers will not be used in tests!"
-					+ " Please set \"--enable-preview --add-modules jdk.incubator.foreign -Dforeign.restricted=permit\"");
+					+ " Please set \"" + MemorySegmentUtils.getSuggestedArgs() + "\"");
 			if (MemorySegmentUtils.getUnsupportedCause() != null) {
 				System.err.println("\tCause: " + MemorySegmentUtils.getUnsupportedCause().getClass().getName()
 						+ ":" + MemorySegmentUtils.getUnsupportedCause().getLocalizedMessage());
@@ -144,7 +179,8 @@ public class DbTestUtils {
 		if (mapType == MapType.MAP) {
 			return DatabaseMapDictionary.simple(dictionary,
 					SerializerFixedBinaryLength.utf8(dictionary.getAllocator(), keyBytes),
-					Serializer.utf8(dictionary.getAllocator())
+					Serializer.utf8(dictionary.getAllocator()),
+					d -> {}
 			);
 		} else {
 			return DatabaseMapDictionaryHashed.simple(dictionary,
@@ -158,7 +194,8 @@ public class DbTestUtils {
 						}
 
 						@Override
-						public @NotNull DeserializationResult<Short> deserialize(@NotNull Send<Buffer> serializedToReceive) {
+						public @NotNull DeserializationResult<Short> deserialize(@Nullable Send<Buffer> serializedToReceive) {
+							Objects.requireNonNull(serializedToReceive);
 							try (var serialized = serializedToReceive.receive()) {
 								var val = serialized.readShort();
 								return new DeserializationResult<>(val, Short.BYTES);
@@ -173,7 +210,8 @@ public class DbTestUtils {
 								return out.send();
 							}
 						}
-					}
+					},
+					d -> {}
 			);
 		}
 	}
@@ -188,7 +226,8 @@ public class DbTestUtils {
 				key2Bytes,
 				new SubStageGetterMap<>(SerializerFixedBinaryLength.utf8(dictionary.getAllocator(), key2Bytes),
 						Serializer.utf8(dictionary.getAllocator())
-				)
+				),
+				d -> {}
 		);
 	}
 
@@ -203,7 +242,8 @@ public class DbTestUtils {
 						Serializer.utf8(dictionary.getAllocator()),
 						String::hashCode,
 						SerializerFixedBinaryLength.intSerializer(dictionary.getAllocator())
-				)
+				),
+				d -> {}
 		);
 	}
 
@@ -213,7 +253,8 @@ public class DbTestUtils {
 				Serializer.utf8(dictionary.getAllocator()),
 				Serializer.utf8(dictionary.getAllocator()),
 				String::hashCode,
-				SerializerFixedBinaryLength.intSerializer(dictionary.getAllocator())
+				SerializerFixedBinaryLength.intSerializer(dictionary.getAllocator()),
+				d -> {}
 		);
 	}
 }

src/test/java/it/cavallium/dbengine/TestDictionaryMap.java

@@ -19,15 +19,20 @@ import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.params.ParameterizedTest;
 import org.junit.jupiter.params.provider.Arguments;
 import org.junit.jupiter.params.provider.MethodSource;
+import org.warp.commonutils.log.Logger;
+import org.warp.commonutils.log.LoggerFactory;
 import reactor.core.publisher.Flux;
 import reactor.core.publisher.Mono;
 import reactor.test.StepVerifier;
 import reactor.test.StepVerifier.Step;
+import reactor.test.util.TestLogger;
+import reactor.util.Loggers;
 import reactor.util.function.Tuple2;
 import reactor.util.function.Tuples;
 
 public abstract class TestDictionaryMap {
 
+	private static final Logger log = LoggerFactory.getLogger(TestDictionaryMap.class);
 	private TestAllocator allocator;
 	private boolean checkLeaks = true;
 
@@ -97,21 +102,24 @@ public abstract class TestDictionaryMap {
 	@ParameterizedTest
 	@MethodSource("provideArgumentsPut")
 	public void testPut(MapType mapType, UpdateMode updateMode, String key, String value, boolean shouldFail) {
-		var stpVer = StepVerifier
+		var gen = getTempDbGenerator();
-				.create(tempDb(getTempDbGenerator(), allocator, db -> tempDictionary(db, updateMode)
+		var db = run(gen.openTempDb(allocator));
-						.map(dict -> tempDatabaseMapDictionaryMap(dict, mapType, 5))
+		var dict = run(tempDictionary(db.db(), updateMode));
-						.flatMap(map -> map
+		var map = tempDatabaseMapDictionaryMap(dict, mapType, 5);
-								.putValue(key, value)
+
-								.then(map.getValue(null, key))
+		runVoid(shouldFail,  map.putValue(key, value));
-								.doAfterTerminate(map::release)
+
-						)
+		var resultingMapSize = run(map.leavesCount(null, false));
-				));
+		Assertions.assertEquals(shouldFail ? 0 : 1, resultingMapSize);
-		if (shouldFail) {
+
-			this.checkLeaks = false;
+		var resultingMap = run(map.get(null));
-			stpVer.verifyError();
+		Assertions.assertEquals(shouldFail ? null : Map.of(key, value), resultingMap);
-		} else {
+
-			stpVer.expectNext(value).verifyComplete();
+		map.close();
-		}
+
+		//if (shouldFail) this.checkLeaks = false;
+
+		gen.closeTempDb(db);
 	}
 
 	@ParameterizedTest
@@ -120,10 +128,10 @@ public abstract class TestDictionaryMap {
 		var stpVer = StepVerifier
 				.create(tempDb(getTempDbGenerator(), allocator, db -> tempDictionary(db, updateMode)
 						.map(dict -> tempDatabaseMapDictionaryMap(dict, mapType, 5))
-						.flatMap(map -> map
+						.flatMap(map -> LLUtils
-								.at(null, key).flatMap(v -> v.set(value).doAfterTerminate(v::release))
+								.usingResource(map.at(null, key), v -> v.set(value), true)
-								.then(map.at(null, key).flatMap(v -> v.get(null).doAfterTerminate(v::release)))
+								.then(LLUtils.usingResource(map.at(null, key), v -> v.get(null), true))
-								.doAfterTerminate(map::release)
+								.doFinally(s -> map.close())
 						)
 				));
 		if (shouldFail) {
@@ -146,7 +154,7 @@ public abstract class TestDictionaryMap {
 										map.putValueAndGetPrevious(key, value),
 										map.putValueAndGetPrevious(key, value)
 								)
-								.doAfterTerminate(map::release)
+								.doFinally(s -> map.close())
 						)
 				));
 		if (shouldFail) {
@@ -169,7 +177,7 @@ public abstract class TestDictionaryMap {
 										map.putValue(key, value).then(map.removeAndGetPrevious(key)),
 										map.removeAndGetPrevious(key)
 								)
-								.doAfterTerminate(map::release)
+								.doFinally(s -> map.close())
 						)
 				));
 		if (shouldFail) {
@@ -192,7 +200,7 @@ public abstract class TestDictionaryMap {
 										map.putValue(key, value).then(map.removeAndGetStatus(key)),
 										map.removeAndGetStatus(key)
 								)
-								.doAfterTerminate(map::release)
+								.doFinally(s -> map.close())
 						)
 				));
 		if (shouldFail) {
@@ -235,7 +243,7 @@ public abstract class TestDictionaryMap {
 											return value;
 										})
 								)
-								.doAfterTerminate(map::release)
+								.doFinally(s -> map.close())
 						)
 						.transform(LLUtils::handleDiscard)
 				));
@@ -257,28 +265,52 @@ public abstract class TestDictionaryMap {
 						.map(dict -> tempDatabaseMapDictionaryMap(dict, mapType, 5))
 						.flatMapMany(map -> Flux
 								.concat(
-										map.updateValue(key, old -> {
+										Mono
+												.fromRunnable(() -> log.debug("1. Updating value: {}", key))
+												.then(map.updateValue(key, old -> {
 													assert old == null;
 													return "error?";
-										}).then(map.getValue(null, key)),
+												}))
-										map.updateValue(key, false, old -> {
+												.doOnSuccess(s -> log.debug("1. Getting value: {}", key))
+												.then(map.getValue(null, key)),
+
+										Mono
+												.fromRunnable(() -> log.debug("2. Updating value: {}", key))
+												.then(map.updateValue(key, false, old -> {
 													assert Objects.equals(old, "error?");
 													return "error?";
-										}).then(map.getValue(null, key)),
+												}))
-										map.updateValue(key, true, old -> {
+												.doOnSuccess(s -> log.debug("2. Getting value: {}", key))
+												.then(map.getValue(null, key)),
+
+										Mono
+												.fromRunnable(() -> log.debug("3. Updating value: {}", key))
+												.then(map.updateValue(key, true, old -> {
 													assert Objects.equals(old, "error?");
 													return "error?";
-										}).then(map.getValue(null, key)),
+												}))
-										map.updateValue(key, true, old -> {
+												.doOnSuccess(s -> log.debug("3. Getting value: {}", key))
+												.then(map.getValue(null, key)),
+
+										Mono
+												.fromRunnable(() -> log.debug("4. Updating value: {}", key))
+												.then(map.updateValue(key, true, old -> {
 													assert Objects.equals(old, "error?");
 													return value;
-										}).then(map.getValue(null, key)),
+												}))
-										map.updateValue(key, true, old -> {
+												.doOnSuccess(s -> log.debug("4. Getting value: {}", key))
+												.then(map.getValue(null, key)),
+
+										Mono
+												.fromRunnable(() -> log.debug("5. Updating value: {}", key))
+												.then(map.updateValue(key, true, old -> {
 													assert Objects.equals(old, value);
 													return value;
-										}).then(map.getValue(null, key))
+												}))
+												.doOnSuccess(s -> log.debug("5. Getting value: {}", key))
+												.then(map.getValue(null, key))
 								)
-								.doAfterTerminate(map::release)
+								.doFinally(s -> map.close())
 						)
 						.transform(LLUtils::handleDiscard)
 				));
@@ -303,7 +335,7 @@ public abstract class TestDictionaryMap {
 										map.remove(key),
 										map.putValueAndGetChanged(key, "error?").single()
 								)
-								.doAfterTerminate(map::release)
+								.doFinally(s -> map.close())
 						)
 				));
 		if (shouldFail) {
@@ -362,7 +394,7 @@ public abstract class TestDictionaryMap {
 										map.putMulti(Flux.fromIterable(entries.entrySet())).then(Mono.empty()),
 										map.getMulti(null, Flux.fromIterable(entries.keySet()))
 								)
-								.doAfterTerminate(map::release)
+								.doFinally(s -> map.close())
 						)
 						.filter(k -> k.getValue().isPresent())
 						.map(k -> Map.entry(k.getKey(), k.getValue().orElseThrow()))
@@ -390,7 +422,7 @@ public abstract class TestDictionaryMap {
 						.flatMapMany(map -> map
 								.setAllValues(Flux.fromIterable(entries.entrySet()))
 								.thenMany(map.getMulti(null, Flux.fromIterable(entries.keySet())))
-								.doAfterTerminate(map::release)
+								.doFinally(s -> map.close())
 						)
 						.filter(k -> k.getValue().isPresent())
 						.map(k -> Map.entry(k.getKey(), k.getValue().orElseThrow()))
@@ -420,7 +452,7 @@ public abstract class TestDictionaryMap {
 										map.setAllValuesAndGetPrevious(Flux.fromIterable(entries.entrySet())),
 										map.setAllValuesAndGetPrevious(Flux.fromIterable(entries.entrySet()))
 								)
-								.doAfterTerminate(map::release)
+								.doFinally(s -> map.close())
 						)
 						.transform(LLUtils::handleDiscard)
 				));
@@ -448,7 +480,7 @@ public abstract class TestDictionaryMap {
 										map.set(entries).then(Mono.empty()),
 										map.getMulti(null, Flux.fromIterable(entries.keySet()))
 								)
-								.doAfterTerminate(map::release)
+								.doFinally(s -> map.close())
 						)
 						.filter(k -> k.getValue().isPresent())
 						.map(k -> Map.entry(k.getKey(), k.getValue().orElseThrow()))
@@ -489,7 +521,7 @@ public abstract class TestDictionaryMap {
 											removalMono.then(Mono.empty()),
 											map.setAndGetChanged(entries).single()
 									)
-									.doAfterTerminate(map::release);
+									.doFinally(s -> map.close());
 						})
 				));
 		if (shouldFail) {
@@ -511,7 +543,7 @@ public abstract class TestDictionaryMap {
 								.concat(map.setAndGetPrevious(entries), map.setAndGetPrevious(entries))
 								.map(Map::entrySet)
 								.concatMapIterable(list -> list)
-								.doAfterTerminate(map::release)
+								.doFinally(s -> map.close())
 						)
 				));
 		if (shouldFail) {
@@ -537,7 +569,7 @@ public abstract class TestDictionaryMap {
 								.concat(map.set(entries).then(Mono.empty()), map.clearAndGetPrevious(), map.get(null))
 								.map(Map::entrySet)
 								.concatMapIterable(list -> list)
-								.doAfterTerminate(map::release)
+								.doFinally(s -> map.close())
 						)
 				));
 		if (shouldFail) {
@@ -564,7 +596,7 @@ public abstract class TestDictionaryMap {
 										map.putMulti(Flux.fromIterable(entries.entrySet())).then(Mono.empty()),
 										map.getAllValues(null)
 								)
-								.doAfterTerminate(map::release)
+								.doFinally(s -> map.close())
 						)
 						.transform(LLUtils::handleDiscard)
 				));
@@ -594,7 +626,7 @@ public abstract class TestDictionaryMap {
 										.map(Map::entrySet)
 										.flatMapIterable(list -> list)
 								)
-								.doAfterTerminate(map::release)
+								.doFinally(s -> map.close())
 						)
 						.transform(LLUtils::handleDiscard)
 				));
@@ -626,10 +658,10 @@ public abstract class TestDictionaryMap {
 														.getValue()
 														.get(null)
 														.map(val -> Map.entry(stage.getKey(), val))
-														.doAfterTerminate(() -> stage.getValue().release())
+														.doFinally(s -> stage.getValue().close())
 												)
 								)
-								.doAfterTerminate(map::release)
+								.doFinally(s -> map.close())
 						)
 						.transform(LLUtils::handleDiscard)
 				));
@@ -658,7 +690,7 @@ public abstract class TestDictionaryMap {
 										map.putMulti(Flux.fromIterable(entries.entrySet())).then(Mono.empty()),
 										map.isEmpty(null)
 								)
-								.doAfterTerminate(map::release)
+								.doFinally(s -> map.close())
 						)
 						.flatMap(val -> shouldFail ? Mono.empty() : Mono.just(val))
 						.transform(LLUtils::handleDiscard)
@@ -685,7 +717,7 @@ public abstract class TestDictionaryMap {
 										map.clear().then(Mono.empty()),
 										map.isEmpty(null)
 								)
-								.doAfterTerminate(map::release)
+								.doFinally(s -> map.close())
 						)
 						.flatMap(val -> shouldFail ? Mono.empty() : Mono.just(val))
 						.transform(LLUtils::handleDiscard)

src/test/java/it/cavallium/dbengine/TestDictionaryMapDeep.java

@@ -5,10 +5,14 @@ import static it.cavallium.dbengine.DbTestUtils.ensureNoLeaks;
 import static it.cavallium.dbengine.DbTestUtils.isCIMode;
 import static it.cavallium.dbengine.DbTestUtils.newAllocator;
 import static it.cavallium.dbengine.DbTestUtils.destroyAllocator;
+import static it.cavallium.dbengine.DbTestUtils.run;
+import static it.cavallium.dbengine.DbTestUtils.runVoid;
 import static it.cavallium.dbengine.DbTestUtils.tempDatabaseMapDictionaryDeepMap;
+import static it.cavallium.dbengine.DbTestUtils.tempDatabaseMapDictionaryMap;
 import static it.cavallium.dbengine.DbTestUtils.tempDb;
 import static it.cavallium.dbengine.DbTestUtils.tempDictionary;
 
+import io.net5.buffer.api.internal.ResourceSupport;
 import it.cavallium.dbengine.DbTestUtils.TestAllocator;
 import it.cavallium.dbengine.database.LLUtils;
 import it.cavallium.dbengine.database.UpdateMode;
@@ -23,12 +27,15 @@ import java.util.concurrent.ConcurrentHashMap;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
 import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.Assertions;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.MethodOrderer;
 import org.junit.jupiter.api.TestMethodOrder;
 import org.junit.jupiter.params.ParameterizedTest;
 import org.junit.jupiter.params.provider.Arguments;
 import org.junit.jupiter.params.provider.MethodSource;
+import org.warp.commonutils.log.Logger;
+import org.warp.commonutils.log.LoggerFactory;
 import reactor.core.publisher.Flux;
 import reactor.core.publisher.Mono;
 import reactor.test.StepVerifier;
@@ -42,6 +49,7 @@ import reactor.util.function.Tuples;
 @TestMethodOrder(MethodOrderer.MethodName.class)
 public abstract class TestDictionaryMapDeep {
 
+	private final Logger log = LoggerFactory.getLogger(this.getClass());
 	private TestAllocator allocator;
 	private boolean checkLeaks = true;
 
@@ -174,22 +182,49 @@ public abstract class TestDictionaryMapDeep {
 
 	@ParameterizedTest
 	@MethodSource("provideArgumentsSet")
-	public void testSetValueGetValue(UpdateMode updateMode, String key, Map<String, String> value, boolean shouldFail) {
+	public void testPutValue(UpdateMode updateMode, String key, Map<String, String> value, boolean shouldFail) {
-		var stpVer = StepVerifier
+		var gen = getTempDbGenerator();
-				.create(tempDb(getTempDbGenerator(), allocator, db -> tempDictionary(db, updateMode)
+		var db = run(gen.openTempDb(allocator));
-						.map(dict -> tempDatabaseMapDictionaryDeepMap(dict, 5, 6))
+		var dict = run(tempDictionary(db.db(), updateMode));
-						.flatMap(map -> map
+		var map = tempDatabaseMapDictionaryDeepMap(dict, 5, 6);
-								.putValue(key, value)
+
-								.then(map.getValue(null, key))
+		log.debug("Put \"{}\" = \"{}\"", key, value);
-								.doAfterTerminate(map::release)
+		runVoid(shouldFail, map.putValue(key, value));
-						)
+
-				));
+		var resultingMapSize = run(map.leavesCount(null, false));
-		if (shouldFail) {
+		Assertions.assertEquals(shouldFail ? 0 : value.size(), resultingMapSize);
-			this.checkLeaks = false;
+
-			stpVer.verifyError();
+		var resultingMap = run(map.get(null));
-		} else {
+		Assertions.assertEquals(shouldFail ? null : Map.of(key, value), resultingMap);
-			stpVer.expectNext(value).verifyComplete();
+
+		map.close();
+
+		//if (shouldFail) this.checkLeaks = false;
+
+		gen.closeTempDb(db);
 	}
+
+	@ParameterizedTest
+	@MethodSource("provideArgumentsSet")
+	public void testGetValue(UpdateMode updateMode, String key, Map<String, String> value, boolean shouldFail) {
+		var gen = getTempDbGenerator();
+		var db = run(gen.openTempDb(allocator));
+		var dict = run(tempDictionary(db.db(), updateMode));
+		var map = tempDatabaseMapDictionaryDeepMap(dict, 5, 6);
+
+		log.debug("Put \"{}\" = \"{}\"", key, value);
+		runVoid(shouldFail, map.putValue(key, value));
+
+		log.debug("Get \"{}\"", key);
+		var returnedValue = run(shouldFail, map.getValue(null, key));
+
+		Assertions.assertEquals(shouldFail ? null : value, returnedValue);
+
+		map.close();
+
+		//if (shouldFail) this.checkLeaks = false;
+
+		gen.closeTempDb(db);
 	}
 
 	@ParameterizedTest
@@ -204,7 +239,7 @@ public abstract class TestDictionaryMapDeep {
 						.flatMapMany(map -> map
 								.putValue(key, value)
 								.thenMany(map.getAllValues(null))
-								.doAfterTerminate(map::release)
+								.doFinally(s -> map.close())
 						)
 				));
 		if (shouldFail) {
@@ -229,14 +264,14 @@ public abstract class TestDictionaryMapDeep {
 								.flatMap(v_ -> Mono.using(
 										() -> v_,
 										v -> v.set(value),
-										DatabaseMapDictionaryDeep::release
+										ResourceSupport::close
 								))
 								.then(map
 										.at(null, "capra")
 										.flatMap(v_ -> Mono.using(
 												() -> v_,
 												v -> v.set(Map.of("normal", "123", "ormaln", "456")),
-												DatabaseMapDictionaryDeep::release
+												ResourceSupport::close
 										))
 								)
 								.thenMany(map
@@ -244,10 +279,10 @@ public abstract class TestDictionaryMapDeep {
 										.flatMap(v -> v.getValue()
 												.getAllValues(null)
 												.map(result -> Tuples.of(v.getKey(), result.getKey(), result.getValue()))
-												.doAfterTerminate(() -> v.getValue().release())
+												.doFinally(s -> v.getValue().close())
 										)
 								),
-								DatabaseMapDictionaryDeep::release
+								ResourceSupport::close
 						))
 				));
 		if (shouldFail) {
@@ -272,9 +307,9 @@ public abstract class TestDictionaryMapDeep {
 				.create(tempDb(getTempDbGenerator(), allocator, db -> tempDictionary(db, updateMode)
 						.map(dict -> tempDatabaseMapDictionaryDeepMap(dict, 5, 6))
 						.flatMap(map -> map
-								.at(null, key1).flatMap(v -> v.putValue(key2, value).doAfterTerminate(v::release))
+								.at(null, key1).flatMap(v -> v.putValue(key2, value).doFinally(s -> v.close()))
-								.then(map.at(null, key1).flatMap(v -> v.getValue(null, key2).doAfterTerminate(v::release)))
+								.then(map.at(null, key1).flatMap(v -> v.getValue(null, key2).doFinally(s -> v.close())))
-								.doAfterTerminate(map::release)
+								.doFinally(s -> map.close())
 						)
 				));
 		if (shouldFail) {
@@ -299,7 +334,7 @@ public abstract class TestDictionaryMapDeep {
 										map.putValueAndGetPrevious(key, value),
 										map.putValueAndGetPrevious(key, value)
 								)
-								.doAfterTerminate(map::release)
+								.doFinally(s -> map.close())
 						)
 				));
 		if (shouldFail) {
@@ -322,22 +357,22 @@ public abstract class TestDictionaryMapDeep {
 												.at(null, key1)
 												.flatMap(v -> v
 														.putValueAndGetPrevious(key2, "error?")
-														.doAfterTerminate(v::release)
+														.doFinally(s -> v.close())
 												),
 										map
 												.at(null, key1)
 												.flatMap(v -> v
 														.putValueAndGetPrevious(key2, value)
-														.doAfterTerminate(v::release)
+														.doFinally(s -> v.close())
 												),
 										map
 												.at(null, key1)
 												.flatMap(v -> v
 														.putValueAndGetPrevious(key2, value)
-														.doAfterTerminate(v::release)
+														.doFinally(s -> v.close())
 												)
 								)
-								.doAfterTerminate(map::release)
+								.doFinally(s -> map.close())
 						)
 				));
 		if (shouldFail) {
@@ -360,7 +395,7 @@ public abstract class TestDictionaryMapDeep {
 										map.putValue(key, value).then(map.removeAndGetPrevious(key)),
 										map.removeAndGetPrevious(key)
 								)
-								.doAfterTerminate(map::release)
+								.doFinally(s -> map.close())
 						)
 				));
 		if (shouldFail) {
@@ -384,22 +419,22 @@ public abstract class TestDictionaryMapDeep {
 												.flatMap(v -> v
 														.putValue(key2, "error?")
 														.then(v.removeAndGetPrevious(key2))
-														.doAfterTerminate(v::release)
+														.doFinally(s -> v.close())
 												),
 										map
 												.at(null, key1)
 												.flatMap(v -> v
 														.putValue(key2, value)
 														.then(v.removeAndGetPrevious(key2))
-														.doAfterTerminate(v::release)
+														.doFinally(s -> v.close())
 												),
 										map
 												.at(null, key1)
 												.flatMap(v -> v.removeAndGetPrevious(key2)
-														.doAfterTerminate(v::release)
+														.doFinally(s -> v.close())
 												)
 								)
-								.doAfterTerminate(map::release)
+								.doFinally(s -> map.close())
 						)
 				));
 		if (shouldFail) {
@@ -422,7 +457,7 @@ public abstract class TestDictionaryMapDeep {
 										map.putValue(key, value).then(map.removeAndGetStatus(key)),
 										map.removeAndGetStatus(key)
 								)
-								.doAfterTerminate(map::release)
+								.doFinally(s -> map.close())
 						)
 				));
 		if (shouldFail) {
@@ -446,22 +481,22 @@ public abstract class TestDictionaryMapDeep {
 												.flatMap(v -> v
 														.putValue(key2, "error?")
 														.then(v.removeAndGetStatus(key2))
-														.doAfterTerminate(v::release)
+														.doFinally(s -> v.close())
 												),
 										map
 												.at(null, key1)
 												.flatMap(v -> v
 														.putValue(key2, value)
 														.then(v.removeAndGetStatus(key2))
-														.doAfterTerminate(v::release)
+														.doFinally(s -> v.close())
 												),
 										map
 												.at(null, key1)
 												.flatMap(v -> v.removeAndGetStatus(key2)
-														.doAfterTerminate(v::release)
+														.doFinally(s -> v.close())
 												)
 								)
-								.doAfterTerminate(map::release)
+								.doFinally(s -> map.close())
 						)
 				));
 		if (shouldFail) {
@@ -504,7 +539,7 @@ public abstract class TestDictionaryMapDeep {
 											return value;
 										})
 								)
-								.doAfterTerminate(map::release)
+								.doFinally(s -> map.close())
 						)
 				));
 		if (updateMode != UpdateMode.ALLOW_UNSAFE || shouldFail) {
@@ -529,28 +564,28 @@ public abstract class TestDictionaryMapDeep {
 												.at(null, key1)
 												.flatMap(v -> v
 														.updateValue(key2, prev -> prev)
-														.doAfterTerminate(v::release)
+														.doFinally(s -> v.close())
 												),
 										map
 												.at(null, key1)
 												.flatMap(v -> v
 														.updateValue(key2, prev -> value)
-														.doAfterTerminate(v::release)
+														.doFinally(s -> v.close())
 												),
 										map
 												.at(null, key1)
 												.flatMap(v -> v
 														.updateValue(key2, prev -> value)
-														.doAfterTerminate(v::release)
+														.doFinally(s -> v.close())
 												),
 										map
 												.at(null, key1)
 												.flatMap(v -> v
 														.updateValue(key2, prev -> null)
-														.doAfterTerminate(v::release)
+														.doFinally(s -> v.close())
 												)
 								)
-								.doAfterTerminate(map::release)
+								.doFinally(s -> map.close())
 								.transform(LLUtils::handleDiscard)
 						)
 				));
@@ -590,7 +625,7 @@ public abstract class TestDictionaryMapDeep {
 							assert Objects.equals(old, value);
 							return value;
 						}).then(map.getValue(null, key))
-				).doAfterTerminate(map::release))
+				).doFinally(s -> map.close()))
 		));
 		if (updateMode != UpdateMode.ALLOW_UNSAFE || shouldFail) {
 			stpVer.verifyError();
@@ -616,7 +651,7 @@ public abstract class TestDictionaryMapDeep {
 														.updateValue(key2, prev -> prev)
 														.then(v.getValue(null, key2))
 														.defaultIfEmpty("empty")
-														.doAfterTerminate(v::release)
+														.doFinally(s -> v.close())
 												),
 										map
 												.at(null, key1)
@@ -624,7 +659,7 @@ public abstract class TestDictionaryMapDeep {
 														.updateValue(key2, prev -> value)
 														.then(v.getValue(null, key2))
 														.defaultIfEmpty("empty")
-														.doAfterTerminate(v::release)
+														.doFinally(s -> v.close())
 												),
 										map
 												.at(null, key1)
@@ -632,7 +667,7 @@ public abstract class TestDictionaryMapDeep {
 														.updateValue(key2, prev -> value)
 														.then(v.getValue(null, key2))
 														.defaultIfEmpty("empty")
-														.doAfterTerminate(v::release)
+														.doFinally(s -> v.close())
 												),
 										map
 												.at(null, key1)
@@ -640,10 +675,10 @@ public abstract class TestDictionaryMapDeep {
 														.updateValue(key2, prev -> null)
 														.then(v.getValue(null, key2))
 														.defaultIfEmpty("empty")
-														.doAfterTerminate(v::release)
+														.doFinally(s -> v.close())
 												)
 								)
-								.doAfterTerminate(map::release)
+								.doFinally(s -> map.close())
 								.transform(LLUtils::handleDiscard)
 						)
 				));
@@ -668,7 +703,7 @@ public abstract class TestDictionaryMapDeep {
 										map.remove(key),
 										map.putValueAndGetChanged(key, Map.of("error?", "error.")).single()
 								)
-								.doAfterTerminate(map::release)
+								.doFinally(s -> map.close())
 						)
 				));
 		if (shouldFail) {
@@ -722,7 +757,7 @@ public abstract class TestDictionaryMapDeep {
 										map.putMulti(Flux.fromIterable(entries.entrySet())).then(Mono.empty()),
 										map.getMulti(null, Flux.fromIterable(entries.keySet()))
 								)
-								.doAfterTerminate(map::release)
+								.doFinally(s -> map.close())
 						)
 						.filter(k -> k.getValue().isPresent())
 						.map(k -> Map.entry(k.getKey(), k.getValue().orElseThrow()))
@@ -750,7 +785,7 @@ public abstract class TestDictionaryMapDeep {
 						.flatMapMany(map -> map
 								.setAllValues(Flux.fromIterable(entries.entrySet()))
 								.thenMany(map.getMulti(null, Flux.fromIterable(entries.keySet())))
-								.doAfterTerminate(map::release)
+								.doFinally(s -> map.close())
 						)
 						.filter(k -> k.getValue().isPresent())
 						.map(k -> Map.entry(k.getKey(), k.getValue().orElseThrow()))
@@ -779,7 +814,7 @@ public abstract class TestDictionaryMapDeep {
 										map.setAllValuesAndGetPrevious(Flux.fromIterable(entries.entrySet())),
 										map.setAllValuesAndGetPrevious(Flux.fromIterable(entries.entrySet()))
 								)
-								.doAfterTerminate(map::release)
+								.doFinally(s -> map.close())
 								.transform(LLUtils::handleDiscard)
 						)
 				));
@@ -807,7 +842,7 @@ public abstract class TestDictionaryMapDeep {
 										map.set(entries).then(Mono.empty()),
 										map.getMulti(null, Flux.fromIterable(entries.keySet()))
 								)
-								.doAfterTerminate(map::release)
+								.doFinally(s -> map.close())
 						)
 						.filter(k -> k.getValue().isPresent())
 						.map(k -> Map.entry(k.getKey(), k.getValue().orElseThrow()))
@@ -845,7 +880,7 @@ public abstract class TestDictionaryMapDeep {
 											removalMono.then(Mono.empty()),
 											map.setAndGetChanged(entries).single()
 									)
-									.doAfterTerminate(map::release);
+									.doFinally(s -> map.close());
 						})
 						.transform(LLUtils::handleDiscard)
 				));
@@ -871,7 +906,7 @@ public abstract class TestDictionaryMapDeep {
 								)
 								.map(Map::entrySet)
 								.concatMapIterable(list -> list)
-								.doAfterTerminate(map::release)
+								.doFinally(s -> map.close())
 						)
 				));
 		if (shouldFail) {
@@ -897,7 +932,7 @@ public abstract class TestDictionaryMapDeep {
 								.concat(map.set(entries).then(Mono.empty()), map.clearAndGetPrevious(), map.get(null))
 								.map(Map::entrySet)
 								.concatMapIterable(list -> list)
-								.doAfterTerminate(map::release)
+								.doFinally(s -> map.close())
 						)
 						.transform(LLUtils::handleDiscard)
 				));
@@ -925,7 +960,7 @@ public abstract class TestDictionaryMapDeep {
 										map.putMulti(Flux.fromIterable(entries.entrySet())).then(Mono.empty()),
 										map.getAllValues(null)
 								)
-								.doAfterTerminate(map::release)
+								.doFinally(s -> map.close())
 						)
 				));
 		if (shouldFail) {
@@ -954,7 +989,7 @@ public abstract class TestDictionaryMapDeep {
 										.map(Map::entrySet)
 										.flatMapIterable(list -> list)
 								)
-								.doAfterTerminate(map::release)
+								.doFinally(s -> map.close())
 						)
 				));
 		if (shouldFail) {
@@ -985,10 +1020,10 @@ public abstract class TestDictionaryMapDeep {
 														.getValue()
 														.get(null)
 														.map(val -> Map.entry(stage.getKey(), val))
-														.doAfterTerminate(() -> stage.getValue().release())
+														.doFinally(s -> stage.getValue().close())
 												)
 								)
-								.doAfterTerminate(map::release)
+								.doFinally(s -> map.close())
 						)
 				));
 		if (shouldFail) {
@@ -1015,7 +1050,7 @@ public abstract class TestDictionaryMapDeep {
 										map.putMulti(Flux.fromIterable(entries.entrySet())).then(Mono.empty()),
 										map.isEmpty(null)
 								)
-								.doAfterTerminate(map::release)
+								.doFinally(s -> map.close())
 						)
 						.transform(LLUtils::handleDiscard)
 				));
@@ -1041,7 +1076,7 @@ public abstract class TestDictionaryMapDeep {
 										map.clear().then(Mono.empty()),
 										map.isEmpty(null)
 								)
-								.doAfterTerminate(map::release)
+								.doFinally(s -> map.close())
 						)
 				));
 		if (shouldFail) {

src/test/java/it/cavallium/dbengine/TestDictionaryMapDeepHashMap.java

@@ -121,14 +121,14 @@ public abstract class TestDictionaryMapDeepHashMap {
 				.create(tempDb(getTempDbGenerator(), allocator, db -> tempDictionary(db, updateMode)
 						.map(dict -> tempDatabaseMapDictionaryDeepMapHashMap(dict, 5))
 						.flatMapMany(map -> map
-								.at(null, key1).flatMap(v -> v.putValue(key2, value).doAfterTerminate(v::release))
+								.at(null, key1).flatMap(v -> v.putValue(key2, value).doFinally(s -> v.close()))
 								.thenMany(map
 										.getAllValues(null)
 										.map(Entry::getValue)
 										.flatMap(maps -> Flux.fromIterable(maps.entrySet()))
 										.map(Entry::getValue)
 								)
-								.doAfterTerminate(map::release)
+								.doFinally(s -> map.close())
 						)
 				));
 		if (shouldFail) {

src/test/java/it/cavallium/dbengine/TestLLDictionary.java

@@ -0,0 +1,311 @@
+package it.cavallium.dbengine;
+
+import static it.cavallium.dbengine.DbTestUtils.destroyAllocator;
+import static it.cavallium.dbengine.DbTestUtils.ensureNoLeaks;
+import static it.cavallium.dbengine.DbTestUtils.newAllocator;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import io.net5.buffer.api.Buffer;
+import io.net5.buffer.api.Send;
+import it.cavallium.dbengine.DbTestUtils.TempDb;
+import it.cavallium.dbengine.DbTestUtils.TestAllocator;
+import it.cavallium.dbengine.database.LLDictionary;
+import it.cavallium.dbengine.database.LLDictionaryResultType;
+import it.cavallium.dbengine.database.LLKeyValueDatabase;
+import it.cavallium.dbengine.database.LLRange;
+import it.cavallium.dbengine.database.LLUtils;
+import it.cavallium.dbengine.database.UpdateMode;
+import it.cavallium.dbengine.database.UpdateReturnMode;
+import java.nio.charset.StandardCharsets;
+import java.util.Arrays;
+import java.util.Objects;
+import java.util.stream.Stream;
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.Arguments;
+import org.junit.jupiter.params.provider.MethodSource;
+import org.warp.commonutils.log.Logger;
+import org.warp.commonutils.log.LoggerFactory;
+import reactor.core.publisher.Flux;
+import reactor.core.publisher.Mono;
+import reactor.core.scheduler.Schedulers;
+
+public abstract class TestLLDictionary {
+
+	private final Logger log = LoggerFactory.getLogger(this.getClass());
+	private static final Mono<Send<LLRange>> RANGE_ALL = Mono.fromCallable(() -> LLRange.all().send());
+	private TestAllocator allocator;
+	private TempDb tempDb;
+	private LLKeyValueDatabase db;
+
+	protected abstract TemporaryDbGenerator getTempDbGenerator();
+
+	@BeforeEach
+	public void beforeEach() {
+		this.allocator = newAllocator();
+		ensureNoLeaks(allocator.allocator(), false, false);
+		tempDb = Objects.requireNonNull(getTempDbGenerator().openTempDb(allocator).block(), "TempDB");
+		db = tempDb.db();
+	}
+
+	@AfterEach
+	public void afterEach() {
+		getTempDbGenerator().closeTempDb(tempDb).block();
+		ensureNoLeaks(allocator.allocator(), true, false);
+		destroyAllocator(allocator);
+	}
+
+	public static Stream<Arguments> provideArguments() {
+		return Arrays.stream(UpdateMode.values()).map(Arguments::of);
+	}
+
+	public static Stream<Arguments> providePutArguments() {
+		var updateModes = Arrays.stream(UpdateMode.values());
+		return updateModes.flatMap(updateMode -> {
+			var resultTypes = Arrays.stream(LLDictionaryResultType.values());
+			return resultTypes.map(resultType -> Arguments.of(updateMode, resultType));
+		});
+	}
+
+	public static Stream<Arguments> provideUpdateArguments() {
+		var updateModes = Arrays.stream(UpdateMode.values());
+		return updateModes.flatMap(updateMode -> {
+			var resultTypes = Arrays.stream(UpdateReturnMode.values());
+			return resultTypes.map(resultType -> Arguments.of(updateMode, resultType));
+		});
+	}
+
+	private LLDictionary getDict(UpdateMode updateMode) {
+		var dict = DbTestUtils.tempDictionary(db, updateMode).blockOptional().orElseThrow();
+		var key1 = Mono.fromCallable(() -> fromString("test-key-1"));
+		var key2 = Mono.fromCallable(() -> fromString("test-key-2"));
+		var key3 = Mono.fromCallable(() -> fromString("test-key-3"));
+		var key4 = Mono.fromCallable(() -> fromString("test-key-4"));
+		var value = Mono.fromCallable(() -> fromString("test-value"));
+		dict.put(key1, value, LLDictionaryResultType.VOID).block();
+		dict.put(key2, value, LLDictionaryResultType.VOID).block();
+		dict.put(key3, value, LLDictionaryResultType.VOID).block();
+		dict.put(key4, value, LLDictionaryResultType.VOID).block();
+		return dict;
+	}
+
+	private Send<Buffer> fromString(String s) {
+		var sb = s.getBytes(StandardCharsets.UTF_8);
+		try (var b = db.getAllocator().allocate(sb.length + 3 + 13)) {
+			assert b.writerOffset() == 0;
+			assert b.readerOffset() == 0;
+			b.writerOffset(3).writeBytes(sb);
+			b.readerOffset(3);
+			assert b.readableBytes() == sb.length;
+
+			var part1 = b.split();
+
+			return LLUtils.compositeBuffer(db.getAllocator(), part1.send(), b.send()).send();
+		}
+	}
+
+	private String toString(Send<Buffer> b) {
+		try (var bb = b.receive()) {
+			byte[] data = new byte[bb.readableBytes()];
+			bb.copyInto(bb.readerOffset(), data, 0, data.length);
+			return new String(data, StandardCharsets.UTF_8);
+		}
+	}
+
+	private void run(Flux<?> publisher) {
+		publisher.subscribeOn(Schedulers.immediate()).blockLast();
+	}
+
+	private void runVoid(Mono<Void> publisher) {
+		publisher.then().subscribeOn(Schedulers.immediate()).block();
+	}
+
+	private <T> T run(Mono<T> publisher) {
+		return publisher.subscribeOn(Schedulers.immediate()).block();
+	}
+
+	private <T> T run(boolean shouldFail, Mono<T> publisher) {
+		return publisher.subscribeOn(Schedulers.immediate()).transform(mono -> {
+			if (shouldFail) {
+				return mono.onErrorResume(ex -> Mono.empty());
+			} else {
+				return mono;
+			}
+		}).block();
+	}
+
+	private void runVoid(boolean shouldFail, Mono<Void> publisher) {
+		publisher.then().subscribeOn(Schedulers.immediate()).transform(mono -> {
+			if (shouldFail) {
+				return mono.onErrorResume(ex -> Mono.empty());
+			} else {
+				return mono;
+			}
+		}).block();
+	}
+
+	@Test
+	public void testNoOp() {
+	}
+
+	@Test
+	public void testNoOpAllocation() {
+		for (int i = 0; i < 10; i++) {
+			var a = allocator.allocator().allocate(i * 512);
+			a.send().receive().close();
+		}
+	}
+
+	@ParameterizedTest
+	@MethodSource("provideArguments")
+	public void testGetDict(UpdateMode updateMode) {
+		var dict = getDict(updateMode);
+		Assertions.assertNotNull(dict);
+	}
+
+	@ParameterizedTest
+	@MethodSource("provideArguments")
+	public void testGetColumnName(UpdateMode updateMode) {
+		var dict = getDict(updateMode);
+		Assertions.assertEquals("hash_map_testmap", dict.getColumnName());
+	}
+
+	@ParameterizedTest
+	@MethodSource("provideArguments")
+	public void testGetAllocator(UpdateMode updateMode) {
+		var dict = getDict(updateMode);
+		var alloc = dict.getAllocator();
+		Assertions.assertEquals(alloc, alloc);
+	}
+
+	@ParameterizedTest
+	@MethodSource("provideArguments")
+	public void testGet(UpdateMode updateMode) {
+		var dict = getDict(updateMode);
+		var keyEx = Mono.fromCallable(() -> fromString("test-key-1"));
+		var keyNonEx = Mono.fromCallable(() -> fromString("test-nonexistent"));
+		Assertions.assertEquals("test-value", run(dict.get(null, keyEx).map(this::toString).transform(LLUtils::handleDiscard)));
+		Assertions.assertEquals("test-value", run(dict.get(null, keyEx, true).map(this::toString).transform(LLUtils::handleDiscard)));
+		Assertions.assertEquals("test-value", run(dict.get(null, keyEx, false).map(this::toString).transform(LLUtils::handleDiscard)));
+		Assertions.assertEquals((String) null, run(dict.get(null, keyNonEx).map(this::toString).transform(LLUtils::handleDiscard)));
+		Assertions.assertEquals((String) null, run(dict.get(null, keyNonEx, true).map(this::toString).transform(LLUtils::handleDiscard)));
+		Assertions.assertEquals((String) null, run(dict.get(null, keyNonEx, false).map(this::toString).transform(LLUtils::handleDiscard)));
+	}
+
+	@ParameterizedTest
+	@MethodSource("providePutArguments")
+	public void testPutExisting(UpdateMode updateMode, LLDictionaryResultType resultType) {
+		var dict = getDict(updateMode);
+		var keyEx = Mono.fromCallable(() -> fromString("test-key-1"));
+		var value = Mono.fromCallable(() -> fromString("test-value"));
+
+		var beforeSize = run(dict.sizeRange(null, RANGE_ALL, false));
+
+		runVoid(dict.put(keyEx, value, resultType).then().doOnDiscard(Send.class, Send::close));
+
+		var afterSize = run(dict.sizeRange(null, RANGE_ALL, false));
+		Assertions.assertEquals(0, afterSize - beforeSize);
+	}
+
+	@ParameterizedTest
+	@MethodSource("providePutArguments")
+	public void testPutNew(UpdateMode updateMode, LLDictionaryResultType resultType) {
+		var dict = getDict(updateMode);
+		var keyNonEx = Mono.fromCallable(() -> fromString("test-nonexistent"));
+		var value = Mono.fromCallable(() -> fromString("test-value"));
+
+		var beforeSize = run(dict.sizeRange(null, RANGE_ALL, false));
+
+		runVoid(dict.put(keyNonEx, value, resultType).then().doOnDiscard(Send.class, Send::close));
+
+		var afterSize = run(dict.sizeRange(null, Mono.fromCallable(() -> LLRange.all().send()), false));
+		Assertions.assertEquals(1, afterSize - beforeSize);
+
+		Assertions.assertTrue(run(dict.getRangeKeys(null, RANGE_ALL).map(this::toString).collectList()).contains("test-nonexistent"));
+	}
+
+	@ParameterizedTest
+	@MethodSource("provideArguments")
+	public void testGetUpdateMode(UpdateMode updateMode) {
+		var dict = getDict(updateMode);
+		assertEquals(updateMode, run(dict.getUpdateMode()));
+	}
+
+	@ParameterizedTest
+	@MethodSource("provideUpdateArguments")
+	public void testUpdateExisting(UpdateMode updateMode, UpdateReturnMode updateReturnMode) {
+		var dict = getDict(updateMode);
+		var keyEx = Mono.fromCallable(() -> fromString("test-key-1"));
+		var beforeSize = run(dict.sizeRange(null, RANGE_ALL, false));
+		long afterSize;
+		runVoid(updateMode == UpdateMode.DISALLOW,
+				dict.update(keyEx, old -> fromString("test-value"), updateReturnMode, true).then().transform(LLUtils::handleDiscard)
+		);
+		afterSize = run(dict.sizeRange(null, RANGE_ALL, false));
+		assertEquals(0, afterSize - beforeSize);
+		runVoid(updateMode == UpdateMode.DISALLOW,
+				dict.update(keyEx, old -> fromString("test-value"), updateReturnMode, false).then().transform(LLUtils::handleDiscard)
+		);
+		afterSize = run(dict.sizeRange(null, RANGE_ALL, false));
+		assertEquals(0, afterSize - beforeSize);
+		runVoid(updateMode == UpdateMode.DISALLOW,
+				dict.update(keyEx, old -> fromString("test-value"), updateReturnMode).then().transform(LLUtils::handleDiscard)
+		);
+		afterSize = run(dict.sizeRange(null, RANGE_ALL, false));
+		assertEquals(0, afterSize - beforeSize);
+	}
+
+	@ParameterizedTest
+	@MethodSource("provideUpdateArguments")
+	public void testUpdateNew(UpdateMode updateMode, UpdateReturnMode updateReturnMode) {
+		int expected = updateMode == UpdateMode.DISALLOW ? 0 : 1;
+		var dict = getDict(updateMode);
+		var keyNonEx = Mono.fromCallable(() -> fromString("test-nonexistent"));
+		var beforeSize = run(dict.sizeRange(null, RANGE_ALL, false));
+		long afterSize;
+		runVoid(updateMode == UpdateMode.DISALLOW,
+				dict.update(keyNonEx, old -> fromString("test-value"), updateReturnMode, true).then().transform(LLUtils::handleDiscard)
+		);
+		afterSize = run(dict.sizeRange(null, RANGE_ALL, false));
+		assertEquals(expected, afterSize - beforeSize);
+		runVoid(updateMode == UpdateMode.DISALLOW,
+				dict.update(keyNonEx, old -> fromString("test-value"), updateReturnMode, false).then().transform(LLUtils::handleDiscard)
+		);
+		afterSize = run(dict.sizeRange(null, RANGE_ALL, false));
+		assertEquals(expected, afterSize - beforeSize);
+		runVoid(updateMode == UpdateMode.DISALLOW,
+				dict.update(keyNonEx, old -> fromString("test-value"), updateReturnMode).then().transform(LLUtils::handleDiscard)
+		);
+		afterSize = run(dict.sizeRange(null, RANGE_ALL, false));
+		assertEquals(expected, afterSize - beforeSize);
+
+		if (updateMode != UpdateMode.DISALLOW) {
+			Assertions.assertTrue(run(dict.getRangeKeys(null, RANGE_ALL).map(this::toString).collectList()).contains(
+					"test-nonexistent"));
+		}
+	}
+
+	@ParameterizedTest
+	@MethodSource("provideArguments")
+	public void testUpdateAndGetDelta(UpdateMode updateMode) {
+		log.warn("Test not implemented");
+		//todo: implement
+	}
+
+	@ParameterizedTest
+	@MethodSource("provideArguments")
+	public void testClear(UpdateMode updateMode) {
+		log.warn("Test not implemented");
+		//todo: implement
+	}
+
+	@ParameterizedTest
+	@MethodSource("providePutArguments")
+	public void testRemove(UpdateMode updateMode, LLDictionaryResultType resultType) {
+		log.warn("Test not implemented");
+		//todo: implement
+	}
+}

src/test/java/it/cavallium/dbengine/TestLLDictionaryLeaks.java

@@ -26,9 +26,7 @@ import org.junit.jupiter.api.Test;
 import org.junit.jupiter.params.ParameterizedTest;
 import org.junit.jupiter.params.provider.Arguments;
 import org.junit.jupiter.params.provider.MethodSource;
-import reactor.core.publisher.Flux;
 import reactor.core.publisher.Mono;
-import reactor.core.scheduler.Schedulers;
 
 public abstract class TestLLDictionaryLeaks {
 
@@ -90,43 +88,12 @@ public abstract class TestLLDictionaryLeaks {
 	private Send<Buffer> fromString(String s) {
 		var sb = s.getBytes(StandardCharsets.UTF_8);
 		try (var b = db.getAllocator().allocate(sb.length)) {
-			b.writeBytes(b);
+			b.writeBytes(sb);
+			assert b.readableBytes() == sb.length;
 			return b.send();
 		}
 	}
 
-	private void run(Flux<?> publisher) {
-		publisher.subscribeOn(Schedulers.immediate()).blockLast();
-	}
-
-	private void runVoid(Mono<Void> publisher) {
-		publisher.then().subscribeOn(Schedulers.immediate()).block();
-	}
-
-	private <T> T run(Mono<T> publisher) {
-		return publisher.subscribeOn(Schedulers.immediate()).block();
-	}
-
-	private <T> T run(boolean shouldFail, Mono<T> publisher) {
-		return publisher.subscribeOn(Schedulers.immediate()).transform(mono -> {
-			if (shouldFail) {
-				return mono.onErrorResume(ex -> Mono.empty());
-			} else {
-				return mono;
-			}
-		}).block();
-	}
-
-	private void runVoid(boolean shouldFail, Mono<Void> publisher) {
-		publisher.then().subscribeOn(Schedulers.immediate()).transform(mono -> {
-			if (shouldFail) {
-				return mono.onErrorResume(ex -> Mono.empty());
-			} else {
-				return mono;
-			}
-		}).block();
-	}
-
 	@Test
 	public void testNoOp() {
 	}
@@ -164,9 +131,9 @@ public abstract class TestLLDictionaryLeaks {
 	public void testGet(UpdateMode updateMode) {
 		var dict = getDict(updateMode);
 		var key = Mono.fromCallable(() -> fromString("test"));
-		runVoid(dict.get(null, key).then().transform(LLUtils::handleDiscard));
+		DbTestUtils.runVoid(dict.get(null, key).then().transform(LLUtils::handleDiscard));
-		runVoid(dict.get(null, key, true).then().transform(LLUtils::handleDiscard));
+		DbTestUtils.runVoid(dict.get(null, key, true).then().transform(LLUtils::handleDiscard));
-		runVoid(dict.get(null, key, false).then().transform(LLUtils::handleDiscard));
+		DbTestUtils.runVoid(dict.get(null, key, false).then().transform(LLUtils::handleDiscard));
 	}
 
 	@ParameterizedTest
@@ -175,14 +142,14 @@ public abstract class TestLLDictionaryLeaks {
 		var dict = getDict(updateMode);
 		var key = Mono.fromCallable(() -> fromString("test-key"));
 		var value = Mono.fromCallable(() -> fromString("test-value"));
-		runVoid(dict.put(key, value, resultType).then().doOnDiscard(Send.class, Send::close));
+		DbTestUtils.runVoid(dict.put(key, value, resultType).then().doOnDiscard(Send.class, Send::close));
 	}
 
 	@ParameterizedTest
 	@MethodSource("provideArguments")
 	public void testGetUpdateMode(UpdateMode updateMode) {
 		var dict = getDict(updateMode);
-		assertEquals(updateMode, run(dict.getUpdateMode()));
+		assertEquals(updateMode, DbTestUtils.run(dict.getUpdateMode()));
 	}
 
 	@ParameterizedTest
@@ -190,13 +157,13 @@ public abstract class TestLLDictionaryLeaks {
 	public void testUpdate(UpdateMode updateMode, UpdateReturnMode updateReturnMode) {
 		var dict = getDict(updateMode);
 		var key = Mono.fromCallable(() -> fromString("test-key"));
-		runVoid(updateMode == UpdateMode.DISALLOW,
+		DbTestUtils.runVoid(updateMode == UpdateMode.DISALLOW,
 				dict.update(key, old -> old, updateReturnMode, true).then().transform(LLUtils::handleDiscard)
 		);
-		runVoid(updateMode == UpdateMode.DISALLOW,
+		DbTestUtils.runVoid(updateMode == UpdateMode.DISALLOW,
 				dict.update(key, old -> old, updateReturnMode, false).then().transform(LLUtils::handleDiscard)
 		);
-		runVoid(updateMode == UpdateMode.DISALLOW,
+		DbTestUtils.runVoid(updateMode == UpdateMode.DISALLOW,
 				dict.update(key, old -> old, updateReturnMode).then().transform(LLUtils::handleDiscard)
 		);
 	}
@@ -206,13 +173,13 @@ public abstract class TestLLDictionaryLeaks {
 	public void testUpdateAndGetDelta(UpdateMode updateMode) {
 		var dict = getDict(updateMode);
 		var key = Mono.fromCallable(() -> fromString("test-key"));
-		runVoid(updateMode == UpdateMode.DISALLOW,
+		DbTestUtils.runVoid(updateMode == UpdateMode.DISALLOW,
 				dict.updateAndGetDelta(key, old -> old, true).then().transform(LLUtils::handleDiscard)
 		);
-		runVoid(updateMode == UpdateMode.DISALLOW,
+		DbTestUtils.runVoid(updateMode == UpdateMode.DISALLOW,
 				dict.updateAndGetDelta(key, old -> old, false).then().transform(LLUtils::handleDiscard)
 		);
-		runVoid(updateMode == UpdateMode.DISALLOW,
+		DbTestUtils.runVoid(updateMode == UpdateMode.DISALLOW,
 				dict.updateAndGetDelta(key, old -> old).then().transform(LLUtils::handleDiscard)
 		);
 	}
@@ -221,7 +188,7 @@ public abstract class TestLLDictionaryLeaks {
 	@MethodSource("provideArguments")
 	public void testClear(UpdateMode updateMode) {
 		var dict = getDict(updateMode);
-		runVoid(dict.clear());
+		DbTestUtils.runVoid(dict.clear());
 	}
 
 	@ParameterizedTest
@@ -229,6 +196,6 @@ public abstract class TestLLDictionaryLeaks {
 	public void testRemove(UpdateMode updateMode, LLDictionaryResultType resultType) {
 		var dict = getDict(updateMode);
 		var key = Mono.fromCallable(() -> fromString("test-key"));
-		runVoid(dict.remove(key, resultType).then().doOnDiscard(Send.class, Send::close));
+		DbTestUtils.runVoid(dict.remove(key, resultType).then().doOnDiscard(Send.class, Send::close));
 	}
 }

src/test/java/it/cavallium/dbengine/TestLocalLLDictionary.java

@@ -0,0 +1,11 @@
+package it.cavallium.dbengine;
+
+public class TestLocalLLDictionary extends TestLLDictionary {
+
+	private static final TemporaryDbGenerator GENERATOR = new LocalTemporaryDbGenerator();
+
+	@Override
+	protected TemporaryDbGenerator getTempDbGenerator() {
+		return GENERATOR;
+	}
+}

src/test/java/it/cavallium/dbengine/TestMemoryLLDictionary.java

@@ -0,0 +1,11 @@
+package it.cavallium.dbengine;
+
+public class TestMemoryLLDictionary extends TestLLDictionary {
+
+	private static final TemporaryDbGenerator GENERATOR = new MemoryTemporaryDbGenerator();
+
+	@Override
+	protected TemporaryDbGenerator getTempDbGenerator() {
+		return GENERATOR;
+	}
+}

src/test/java/it/cavallium/dbengine/database/collections/TestRanges.java

@@ -51,7 +51,7 @@ public class TestRanges {
 		byte[] firstRangeKey;
 		try (var firstRangeKeyBuf = DatabaseMapDictionaryDeep.firstRangeKey(alloc,
 				alloc.allocate(prefixKey.length).writeBytes(prefixKey).send(),
-				prefixKey.length, 7, 3).receive()) {
+				prefixKey.length, 7, 3)) {
 			firstRangeKey = LLUtils.toArray(firstRangeKeyBuf);
 		}
 		byte[] nextRangeKey;
@@ -60,7 +60,7 @@ public class TestRanges {
 				prefixKey.length,
 				7,
 				3
-		).receive()) {
+		)) {
 			nextRangeKey = LLUtils.toArray(nextRangeKeyBuf);
 		}
 
@@ -114,7 +114,7 @@ public class TestRanges {
 				prefixKey.length,
 				3,
 				7
-		).receive()) {
+		)) {
 			firstRangeKey = LLUtils.toArray(firstRangeKeyBuf);
 		}
 		try (var nextRangeKeyBuf = DatabaseMapDictionaryDeep.nextRangeKey(alloc,
@@ -123,7 +123,7 @@ public class TestRanges {
 				prefixKey.length,
 				3,
 				7
-		).receive()) {
+		)) {
 			byte[] nextRangeKey = LLUtils.toArray(nextRangeKeyBuf);
 
 			if (Arrays.equals(prefixKey, new byte[] {(byte) 0xFF, (byte) 0xFF, (byte) 0xFF}) && Arrays.equals(suffixKey, new byte[] {(byte) 0xFF, (byte) 0xFF, (byte) 0xFF})) {

src/test/resources/log4j2.xml

@@ -0,0 +1,20 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<Configuration strict="true"
+  xmlns="http://logging.apache.org/log4j/2.0/config"
+  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+  xsi:schemaLocation="http://logging.apache.org/log4j/2.0/config
+  https://raw.githubusercontent.com/apache/logging-log4j2/log4j-2.14.1/log4j-core/src/main/resources/Log4j-config.xsd"
+  status="ALL">
+  <Appenders>
+    <Console name="Console" target="SYSTEM_OUT">
+      <PatternLayout
+        pattern="%d{${LOG_DATEFORMAT_PATTERN:-yyyy-MM-dd HH:mm:ss.SSS}} %highlight{${LOG_LEVEL_PATTERN:-%5p}}{FATAL=red blink, ERROR=red, WARN=yellow bold, INFO=green, DEBUG=green bold, TRACE=blue} %style{%processId}{magenta} %style{%-20.20c{1}}{cyan} : %m%n%ex"/>
+    </Console>
+
+  </Appenders>
+  <Loggers>
+    <Root level="ALL">
+      <AppenderRef ref="Console"/>
+    </Root>
+  </Loggers>
+</Configuration>