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

72 lines
2.0 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,
Mono<ByteBuf> keyPrefixMono,
Flux<ByteBuf> debuggingKeysFlux) {
return Mono.usingWhen(
keyPrefixMono,
keyPrefix -> Mono
.<DatabaseStageEntry<T>>fromSupplier(() -> new DatabaseSingle<>(dictionary, keyPrefix.retain(), serializer))
.transform(mono -> {
if (assertsEnabled && needsDebuggingKeyFlux()) {
return debuggingKeysFlux.handle((key, sink) -> {
try {
if (!LLUtils.equals(keyPrefix, key)) {
sink.error(new IndexOutOfBoundsException("Found more than one element!"));
} else {
sink.complete();
}
} finally {
key.release();
}
}).then(mono);
} else {
return mono;
}
}),
keyPrefix -> Mono.fromRunnable(keyPrefix::release)
);
}
@Override
public boolean isMultiKey() {
return false;
}
@Override
public boolean needsDebuggingKeyFlux() {
return assertsEnabled;
}
}