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.kv; import com.google.protobuf.InvalidProtocolBufferException; import com.google.protobuf.UnsafeByteOperations; import io.netty.buffer.ByteBuf; import io.netty.buffer.ByteBufOutputStream; import io.netty.buffer.PooledByteBufAllocator; import java.io.IOException; import lombok.AccessLevel; import lombok.NoArgsConstructor; import lombok.extern.slf4j.Slf4j; import org.apache.bookkeeper.common.coder.Coder; import org.apache.bookkeeper.proto.statestore.kv.Command; import org.apache.bookkeeper.proto.statestore.kv.DeleteRequest; import org.apache.bookkeeper.proto.statestore.kv.NopRequest; import org.apache.bookkeeper.proto.statestore.kv.PutIfAbsentRequest; import org.apache.bookkeeper.proto.statestore.kv.PutRequest; /** * Utils for kv stores. */ @Slf4j @NoArgsConstructor(access = AccessLevel.PRIVATE) final class KVUtils { static final Command NOP_CMD = Command.newBuilder().setNopReq(NopRequest.newBuilder().build()).build(); static ByteBuf serialize(ByteBuf valBuf, long revision) { int serializedSize = valBuf.readableBytes() + Long.BYTES; ByteBuf buffer = PooledByteBufAllocator.DEFAULT.heapBuffer(serializedSize); buffer.writeLong(revision); buffer.writeBytes(valBuf); return buffer; } static ByteBuf serialize(byte[] value, long revision) { int serializedSize = value.length + Long.BYTES; ByteBuf buffer = PooledByteBufAllocator.DEFAULT.heapBuffer(serializedSize); buffer.writeLong(revision); buffer.writeBytes(value); return buffer; } static <V> V deserialize(Coder<V> valCoder, ByteBuf valBuf) { valBuf.skipBytes(Long.BYTES); return valCoder.decode(valBuf); } static Command newCommand(ByteBuf cmdBuf) throws InvalidProtocolBufferException { return Command.parseFrom(cmdBuf.nioBuffer()); } static ByteBuf newCommandBuf(Command cmd) throws IOException { ByteBuf buf = PooledByteBufAllocator.DEFAULT.buffer(cmd.getSerializedSize()); try { cmd.writeTo(new ByteBufOutputStream(buf)); } catch (IOException e) { buf.release(); throw e; } return buf; } static PutRequest newPutRequest(byte[] keyBytes, byte[] valBytes) { return PutRequest.newBuilder().setKey(UnsafeByteOperations.unsafeWrap(keyBytes)) .setValue(UnsafeByteOperations.unsafeWrap(valBytes)).build(); } static PutIfAbsentRequest newPutIfAbsentRequest(byte[] keyBytes, byte[] valBytes) { return PutIfAbsentRequest.newBuilder().setKey(UnsafeByteOperations.unsafeWrap(keyBytes)) .setValue(UnsafeByteOperations.unsafeWrap(valBytes)).build(); } static DeleteRequest newDeleteRequest(byte[] keyBytes) { return DeleteRequest.newBuilder().setKey(UnsafeByteOperations.unsafeWrap(keyBytes)).build(); } }