101 lines
3.0 KiB
Java
101 lines
3.0 KiB
Java
package it.cavallium.dbengine.database.collections;
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import io.netty.buffer.ByteBuf;
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import it.cavallium.dbengine.client.CompositeSnapshot;
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import it.cavallium.dbengine.database.LLDictionary;
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import it.cavallium.dbengine.database.LLDictionaryResultType;
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import it.cavallium.dbengine.database.LLRange;
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import it.cavallium.dbengine.database.LLSnapshot;
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import it.cavallium.dbengine.database.serialization.Serializer;
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import java.util.Optional;
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import java.util.function.Function;
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import org.jetbrains.annotations.Nullable;
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import reactor.core.publisher.Mono;
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import static io.netty.buffer.Unpooled.*;
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public class DatabaseSingle<U> implements DatabaseStageEntry<U> {
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private final LLDictionary dictionary;
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private final ByteBuf key;
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private final Serializer<U, ByteBuf> serializer;
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public DatabaseSingle(LLDictionary dictionary, ByteBuf key, Serializer<U, ByteBuf> serializer) {
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try {
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this.dictionary = dictionary;
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if (!key.isDirect()) {
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throw new IllegalArgumentException("Key must be direct");
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}
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this.key = key.retain();
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this.serializer = serializer;
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} finally {
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key.release();
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}
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}
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private LLSnapshot resolveSnapshot(@Nullable CompositeSnapshot snapshot) {
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if (snapshot == null) {
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return null;
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} else {
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return snapshot.getSnapshot(dictionary);
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}
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}
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@Override
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public Mono<U> get(@Nullable CompositeSnapshot snapshot, boolean existsAlmostCertainly) {
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return dictionary.get(resolveSnapshot(snapshot), key.retain(), existsAlmostCertainly).map(this::deserialize);
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}
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@Override
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public Mono<U> setAndGetPrevious(U value) {
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ByteBuf valueByteBuf = serialize(value);
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return dictionary
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.put(key.retain(), valueByteBuf.retain(), LLDictionaryResultType.PREVIOUS_VALUE)
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.map(this::deserialize)
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.doFinally(s -> valueByteBuf.release());
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}
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@Override
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public Mono<Boolean> update(Function<@Nullable U, @Nullable U> updater, boolean existsAlmostCertainly) {
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return dictionary.update(key.retain(), (oldValueSer) -> {
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var result = updater.apply(oldValueSer == null ? null : this.deserialize(oldValueSer));
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if (result == null) {
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return null;
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} else {
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return this.serialize(result);
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}
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}, existsAlmostCertainly);
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}
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@Override
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public Mono<U> clearAndGetPrevious() {
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return dictionary.remove(key.retain(), LLDictionaryResultType.PREVIOUS_VALUE).map(this::deserialize);
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}
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@Override
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public Mono<Long> leavesCount(@Nullable CompositeSnapshot snapshot, boolean fast) {
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return dictionary
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.isRangeEmpty(resolveSnapshot(snapshot), LLRange.single(key.retain()))
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.map(empty -> empty ? 0L : 1L);
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}
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@Override
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public Mono<Boolean> isEmpty(@Nullable CompositeSnapshot snapshot) {
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return dictionary
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.isRangeEmpty(resolveSnapshot(snapshot), LLRange.single(key.retain()));
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}
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//todo: temporary wrapper. convert the whole class to buffers
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private U deserialize(ByteBuf bytes) {
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return serializer.deserialize(bytes);
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}
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//todo: temporary wrapper. convert the whole class to buffers
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private ByteBuf serialize(U bytes) {
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return serializer.serialize(bytes);
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}
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@Override
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public void release() {
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key.release();
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}
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} |