CavalliumDBEngine/src/main/java/it/cavallium/dbengine/database/collections/SubStageGetterSingle.java
2021-05-12 21:41:47 +02:00

73 lines
1.9 KiB
Java

package it.cavallium.dbengine.database.collections;
import io.netty.buffer.ByteBuf;
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 java.util.Arrays;
import java.util.List;
import org.jetbrains.annotations.Nullable;
import reactor.core.publisher.Flux;
import reactor.core.publisher.Mono;
public class SubStageGetterSingle<T> implements SubStageGetter<T, DatabaseStageEntry<T>> {
private static final boolean assertsEnabled;
static {
boolean assertsEnabledTmp = false;
//noinspection AssertWithSideEffects
assert assertsEnabledTmp = true;
//noinspection ConstantConditions
assertsEnabled = assertsEnabledTmp;
}
private final Serializer<T, ByteBuf> serializer;
public SubStageGetterSingle(Serializer<T, ByteBuf> serializer) {
this.serializer = serializer;
}
@Override
public Mono<DatabaseStageEntry<T>> subStage(LLDictionary dictionary,
@Nullable CompositeSnapshot snapshot,
ByteBuf keyPrefix,
List<ByteBuf> debuggingKeys) {
try {
return Mono
.fromCallable(() -> {
try {
for (ByteBuf key : debuggingKeys) {
if (!LLUtils.equals(keyPrefix, key)) {
throw new IndexOutOfBoundsException("Found more than one element!");
}
}
return null;
} finally {
for (ByteBuf key : debuggingKeys) {
key.release();
}
}
})
.then(Mono
.<DatabaseStageEntry<T>>fromSupplier(() -> new DatabaseSingle<>(dictionary, keyPrefix.retain(), serializer))
)
.doFirst(keyPrefix::retain)
.doAfterTerminate(keyPrefix::release);
} finally {
keyPrefix.release();
}
}
@Override
public boolean isMultiKey() {
return false;
}
@Override
public boolean needsDebuggingKeyFlux() {
return assertsEnabled;
}
}