Speed optimizations

src/example/java/it.cavallium.dbengine.client/SpeedExample.java

@@ -187,7 +187,7 @@ public class SpeedExample {
 		return test("MapDictionaryDeep::at::put (same key, same value, " + batchSize + " times)",
 				tempDb()
 						.flatMap(db -> db.getDictionary("testmap", UpdateMode.DISALLOW).map(dict -> Tuples.of(db, dict)))
-						.map(tuple -> tuple.mapT2(dict -> DatabaseMapDictionaryDeep.simple(dict, ser, ssg))),
+						.map(tuple -> tuple.mapT2(dict -> DatabaseMapDictionary.simple(dict, ser, ssg))),
 				tuple -> Flux.range(0, batchSize).flatMap(n -> Mono
 						.defer(() -> Mono
 								.fromRunnable(() -> {
@@ -214,7 +214,7 @@ public class SpeedExample {
 		return test("MapDictionaryDeep::putValueAndGetPrevious (same key, same value, " + batchSize + " times)",
 				tempDb()
 						.flatMap(db -> db.getDictionary("testmap", UpdateMode.DISALLOW).map(dict -> Tuples.of(db, dict)))
-						.map(tuple -> tuple.mapT2(dict -> DatabaseMapDictionaryDeep.simple(dict, ser, ssg))),
+						.map(tuple -> tuple.mapT2(dict -> DatabaseMapDictionary.simple(dict, ser, ssg))),
 				tuple -> Flux.range(0, batchSize).flatMap(n -> Mono
 						.defer(() -> Mono
 								.fromRunnable(() -> {
@@ -233,7 +233,7 @@ public class SpeedExample {
 	}
 
 	private static Mono<Void> testPutValue(int valSize) {
-		var ssg = new SubStageGetterSingleBytes();
+		var ssg = Serializer.noop();
 		var ser = SerializerFixedBinaryLength.noop(4);
 		var itemKey = new byte[]{0, 1, 2, 3};
 		var newValue = new byte[valSize];
@@ -243,7 +243,7 @@ public class SpeedExample {
 		return test("MapDictionaryDeep::putValue (same key, same value, " + valSize + " bytes, " + batchSize + " times)",
 				tempDb()
 						.flatMap(db -> db.getDictionary("testmap", UpdateMode.DISALLOW).map(dict -> Tuples.of(db, dict)))
-						.map(tuple -> tuple.mapT2(dict -> DatabaseMapDictionaryDeep.simple(dict, ser, ssg))),
+						.map(tuple -> tuple.mapT2(dict -> DatabaseMapDictionary.simple(dict, ser, ssg))),
 				tuple -> Flux.range(0, batchSize).flatMap(n -> Mono
 						.defer(() -> Mono
 								.fromRunnable(() -> {
@@ -270,7 +270,7 @@ public class SpeedExample {
 		return test("MapDictionaryDeep::updateValue (same key, alternating value, " + valSize + " bytes, " + batchSize + " times)",
 				tempDb()
 						.flatMap(db -> db.getDictionary("testmap", UpdateMode.ALLOW).map(dict -> Tuples.of(db, dict)))
-						.map(tuple -> tuple.mapT2(dict -> DatabaseMapDictionaryDeep.simple(dict, ser, ssg))),
+						.map(tuple -> tuple.mapT2(dict -> DatabaseMapDictionary.simple(dict, ser, ssg))),
 				tuple -> Flux.range(0, batchSize).flatMap(n -> Mono
 						.defer(() -> tuple.getT2().updateValue(itemKey, (old) -> {
 									if (old.isPresent()) {
@@ -297,7 +297,7 @@ public class SpeedExample {
 		return test("MapDictionaryDeep::putMulti (batch of " + batchSize + " entries)",
 				tempDb()
 						.flatMap(db -> db.getDictionary("testmap", UpdateMode.DISALLOW).map(dict -> Tuples.of(db, dict)))
-						.map(tuple -> tuple.mapT2(dict -> DatabaseMapDictionaryDeep.simple(dict, ser, ssg))),
+						.map(tuple -> tuple.mapT2(dict -> DatabaseMapDictionary.simple(dict, ser, ssg))),
 				tuple -> Mono.defer(() -> tuple.getT2().putMulti(putMultiFlux)),
 				numRepeats,
 				tuple -> Mono

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

@@ -178,16 +178,26 @@ public class DatabaseMapDictionary<T, U> extends DatabaseMapDictionaryDeep<T, U,
 	public Flux<Entry<T, DatabaseStageEntry<U>>> getAllStages(@Nullable CompositeSnapshot snapshot) {
 		return dictionary
 				.getRangeKeys(resolveSnapshot(snapshot), range)
-				.map(keySuffix -> Map.entry(deserializeSuffix(stripPrefix(keySuffix)),
+				.map(key -> Map.entry(deserializeSuffix(stripPrefix(key)),
 						new DatabaseSingleMapped<>(
 								new DatabaseSingle<>(dictionary,
-										toKey(stripPrefix(keySuffix)),
+										toKey(stripPrefix(key)),
 										Serializer.noop()),
 								valueSerializer
 						)
 				));
 	}
 
+	@Override
+	public Flux<Entry<T, U>> getAllValues(@Nullable CompositeSnapshot snapshot) {
+		return dictionary
+				.getRange(resolveSnapshot(snapshot), range)
+				.map(serializedEntry -> Map.entry(
+						deserializeSuffix(stripPrefix(serializedEntry.getKey())),
+						valueSerializer.deserialize(serializedEntry.getValue())
+				));
+	}
+
 	@Override
 	public Flux<Entry<T, U>> setAllValuesAndGetPrevious(Flux<Entry<T, U>> entries) {
 		return dictionary

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

@@ -614,6 +614,7 @@ public class LLLocalDictionary implements LLDictionary {
 				prefixLength,
 				range,
 				resolveSnapshot(snapshot),
+				true,
 				"getRangeKeysGrouped"
 		).flux().subscribeOn(dbScheduler);
 	}
@@ -746,7 +747,7 @@ public class LLLocalDictionary implements LLDictionary {
 
 					// readOpts.setIgnoreRangeDeletions(true);
 					readOpts.setFillCache(false);
-					readOpts.setReadaheadSize(2 * 1024 * 1024);
+					//readOpts.setReadaheadSize(2 * 1024 * 1024);
 					try (CappedWriteBatch writeBatch = new CappedWriteBatch(db,
 							CAPPED_WRITE_BATCH_CAP,
 							RESERVED_WRITE_BATCH_SIZE,
@@ -925,7 +926,7 @@ public class LLLocalDictionary implements LLDictionary {
 	private long exactSizeAll(@Nullable LLSnapshot snapshot) {
 		var readOpts = resolveSnapshot(snapshot);
 		readOpts.setFillCache(false);
-		readOpts.setReadaheadSize(2 * 1024 * 1024);
+		//readOpts.setReadaheadSize(2 * 1024 * 1024);
 		readOpts.setVerifyChecksums(VERIFY_CHECKSUMS_WHEN_NOT_NEEDED);
 
 		if (PARALLEL_EXACT_SIZE) {

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

@@ -16,7 +16,7 @@ public class LLLocalGroupedEntryReactiveRocksIterator extends
 			LLRange range,
 			ReadOptions readOptions,
 			String debugName) {
-		super(db, cfh, prefixLength, range, readOptions, true, debugName);
+		super(db, cfh, prefixLength, range, readOptions, false, true, debugName);
 	}
 
 	@Override

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

@@ -13,7 +13,7 @@ public class LLLocalGroupedKeyReactiveRocksIterator extends LLLocalGroupedReacti
 			LLRange range,
 			ReadOptions readOptions,
 			String debugName) {
-		super(db, cfh, prefixLength, range, readOptions, false, debugName);
+		super(db, cfh, prefixLength, range, readOptions, true, false, debugName);
 	}
 
 	@Override

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

@@ -22,6 +22,7 @@ public abstract class LLLocalGroupedReactiveRocksIterator<T> {
 	private final int prefixLength;
 	private final LLRange range;
 	private final ReadOptions readOptions;
+	private final boolean canFillCache;
 	private final boolean readValues;
 	private final String debugName;
 
@@ -30,6 +31,7 @@ public abstract class LLLocalGroupedReactiveRocksIterator<T> {
 			int prefixLength,
 			LLRange range,
 			ReadOptions readOptions,
+			boolean canFillCache,
 			boolean readValues,
 			String debugName) {
 		this.db = db;
@@ -37,6 +39,7 @@ public abstract class LLLocalGroupedReactiveRocksIterator<T> {
 		this.prefixLength = prefixLength;
 		this.range = range;
 		this.readOptions = readOptions;
+		this.canFillCache = canFillCache;
 		this.readValues = readValues;
 		this.debugName = debugName;
 	}
@@ -47,7 +50,7 @@ public abstract class LLLocalGroupedReactiveRocksIterator<T> {
 		return Flux
 				.generate(() -> {
 					var readOptions = new ReadOptions(this.readOptions);
-					readOptions.setFillCache(range.hasMin() && range.hasMax());
+					readOptions.setFillCache(canFillCache && range.hasMin() && range.hasMax());
 					Slice sliceMin;
 					Slice sliceMax;
 					if (range.hasMin()) {

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

@@ -20,6 +20,7 @@ public class LLLocalKeyPrefixReactiveRocksIterator {
 	private final int prefixLength;
 	private final LLRange range;
 	private final ReadOptions readOptions;
+	private final boolean canFillCache;
 	private final String debugName;
 
 	public LLLocalKeyPrefixReactiveRocksIterator(RocksDB db,
@@ -27,12 +28,14 @@ public class LLLocalKeyPrefixReactiveRocksIterator {
 			int prefixLength,
 			LLRange range,
 			ReadOptions readOptions,
+			boolean canFillCache,
 			String debugName) {
 		this.db = db;
 		this.cfh = cfh;
 		this.prefixLength = prefixLength;
 		this.range = range;
 		this.readOptions = readOptions;
+		this.canFillCache = canFillCache;
 		this.debugName = debugName;
 	}
 
@@ -42,8 +45,8 @@ public class LLLocalKeyPrefixReactiveRocksIterator {
 				.generate(() -> {
 					var readOptions = new ReadOptions(this.readOptions);
 					if (!range.hasMin() || !range.hasMax()) {
-						readOptions.setReadaheadSize(2 * 1024 * 1024);
+						//readOptions.setReadaheadSize(2 * 1024 * 1024);
-						readOptions.setFillCache(false);
+						readOptions.setFillCache(canFillCache);
 					}
 					Slice sliceMin;
 					Slice sliceMax;

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

@@ -91,7 +91,7 @@ public class LLLocalKeyValueDatabase implements LLKeyValueDatabase {
 			if (lowMemory) {
 				this.dbScheduler = lowMemorySupplier.get();
 			} else {
-				this.dbScheduler = Schedulers.newBoundedElastic(6,
+				this.dbScheduler = Schedulers.newBoundedElastic(Math.max(8, Runtime.getRuntime().availableProcessors()),
 						Schedulers.DEFAULT_BOUNDED_ELASTIC_QUEUESIZE,
 						"db-" + name,
 						60,
@@ -209,7 +209,7 @@ public class LLLocalKeyValueDatabase implements LLKeyValueDatabase {
 		//options.setUseDirectReads(true);
 		//options.setUseDirectIoForFlushAndCompaction(true);
 		//options.setWritableFileMaxBufferSize(1024 * 1024); // 1MB by default
-		options.setCompactionReadaheadSize(2 * 1024 * 1024); // recommend at least 2MB
+		//options.setCompactionReadaheadSize(2 * 1024 * 1024); // recommend at least 2MB
 		final BlockBasedTableConfig tableOptions = new BlockBasedTableConfig();
 		if (lowMemory) {
 			// LOW MEMORY