Java tutorial
/* * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The ASF licenses this file * to you under the Apache License, Version 2.0 (the * "License"); you may not use this file except in compliance * with the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package org.apache.bookkeeper.statelib.impl.mvcc; import io.netty.buffer.ByteBuf; import io.netty.util.Recycler; import java.util.function.Predicate; import lombok.Data; import lombok.Getter; import lombok.Setter; import org.apache.bookkeeper.api.kv.impl.result.KeyValueFactory; import org.apache.bookkeeper.api.kv.impl.result.KeyValueImpl; import org.apache.bookkeeper.api.kv.options.RangeOption; import org.apache.bookkeeper.common.coder.Coder; import org.apache.bookkeeper.common.util.Recycled; import org.apache.bookkeeper.stream.proto.kv.store.ValueType; /** * An object represents the mvcc metdata and value for a given key. */ @Data @Setter @Getter public class MVCCRecord implements Recycled, Predicate<RangeOption<?>> { public static MVCCRecord newRecord() { return RECYCLER.get(); } private static final Recycler<MVCCRecord> RECYCLER = new Recycler<MVCCRecord>() { @Override protected MVCCRecord newObject(Handle<MVCCRecord> handle) { return new MVCCRecord(handle); } }; private ByteBuf value; private long number; private final Recycler.Handle<MVCCRecord> handle; private long createRev; private long modRev; private long version; private ValueType valueType = ValueType.BYTES; private MVCCRecord(Recycler.Handle<MVCCRecord> handle) { this.handle = handle; } public MVCCRecord duplicate() { MVCCRecord record = newRecord(); record.createRev = createRev; record.modRev = modRev; record.version = version; record.valueType = valueType; record.value = value.retainedSlice(); record.number = number; return record; } public int compareModRev(long revision) { return Long.compare(modRev, revision); } public int compareCreateRev(long revision) { return Long.compare(createRev, revision); } public int compareVersion(long version) { return Long.compare(this.version, version); } public void setValue(ByteBuf buf, ValueType valueType) { if (null != value) { value.release(); } this.value = buf; this.valueType = valueType; if (ValueType.NUMBER == valueType) { this.number = buf.getLong(0); } } private void reset() { if (null != value) { value.release(); value = null; } modRev = -1L; createRev = -1L; version = -1L; number = -1L; valueType = ValueType.BYTES; } @Override public void recycle() { reset(); handle.recycle(this); } <K, V> KeyValueImpl<K, V> asKVRecord(KeyValueFactory<K, V> recordFactory, K key, Coder<V> valCoder) { return recordFactory.newKv().key(key).value(valCoder.decode(value)).createRevision(createRev) .modifiedRevision(modRev).version(version).isNumber(ValueType.NUMBER == valueType) .numberValue(number); } @Override public boolean test(RangeOption<?> rangeOption) { if (null == rangeOption) { return true; } return createRev >= rangeOption.minCreateRev() && createRev <= rangeOption.maxCreateRev() && modRev >= rangeOption.minModRev() && modRev <= rangeOption.maxModRev(); } }