gaoyunhaii commented on a change in pull request #7368: [FLINK-10742][network] Let Netty use Flink's buffers directly in credit-based mode URL: https://github.com/apache/flink/pull/7368#discussion_r390467225
########## File path: flink-runtime/src/main/java/org/apache/flink/runtime/io/network/netty/NettyMessageClientDecoderDelegate.java ########## @@ -0,0 +1,153 @@ +/* + * 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.flink.runtime.io.network.netty; + +import org.apache.flink.runtime.io.network.NetworkClientHandler; +import org.apache.flink.shaded.netty4.io.netty.buffer.ByteBuf; +import org.apache.flink.shaded.netty4.io.netty.channel.ChannelHandlerContext; +import org.apache.flink.shaded.netty4.io.netty.channel.ChannelInboundHandlerAdapter; +import org.apache.flink.util.IOUtils; + +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +import static org.apache.flink.runtime.io.network.netty.NettyMessage.FRAME_HEADER_LENGTH; +import static org.apache.flink.runtime.io.network.netty.NettyMessage.MAGIC_NUMBER; +import static org.apache.flink.util.Preconditions.checkNotNull; +import static org.apache.flink.util.Preconditions.checkState; + +/** + * Decodes messages from the received netty buffers. This decoder assumes the + * messages have the following format: + * +-----------------------------------+--------------------------------+ + * | FRAME_HEADER || MESSAGE_HEADER | DATA BUFFER (Optional) | + * +-----------------------------------+--------------------------------+ + * + * <p>This decoder decodes the frame header and delegates the following work to the + * corresponding message decoders according to the message type. During this process + * The frame header and message header are only accumulated if they span received + * multiple netty buffers, and the data buffer is copied directly to the buffer + * of corresponding input channel to avoid more copying. + * + * <p>The format of the frame header is + * +------------------+------------------+--------+ + * | FRAME LENGTH (4) | MAGIC NUMBER (4) | ID (1) | + * +------------------+------------------+--------+ + */ +public class NettyMessageClientDecoderDelegate extends ChannelInboundHandlerAdapter { + private final Logger LOG = LoggerFactory.getLogger(NettyMessageClientDecoderDelegate.class); + + /** The decoder for BufferResponse. */ + private final NettyMessageDecoder bufferResponseDecoder; + + /** The decoder for messages other than BufferResponse. */ + private final NettyMessageDecoder nonBufferResponseDecoder; + + /** The accumulation buffer for the frame header. */ + private ByteBuf frameHeaderBuffer; + + /** The decoder for the current message. It is null if we are decoding the frame header. */ + private NettyMessageDecoder currentDecoder; + + NettyMessageClientDecoderDelegate(NetworkClientHandler networkClientHandler) { + this.bufferResponseDecoder = new BufferResponseDecoder( + new NetworkBufferAllocator( + checkNotNull(networkClientHandler))); + this.nonBufferResponseDecoder = new NonBufferResponseDecoder(); + } + + @Override + public void channelActive(ChannelHandlerContext ctx) throws Exception { + bufferResponseDecoder.onChannelActive(ctx); + nonBufferResponseDecoder.onChannelActive(ctx); + + frameHeaderBuffer = ctx.alloc().directBuffer(FRAME_HEADER_LENGTH); + + super.channelActive(ctx); + } + + /** + * Releases resources when the channel is closed. When exceptions are thrown during + * processing received netty buffers, {@link CreditBasedPartitionRequestClientHandler} + * is expected to catch the exception and close the channel and trigger this notification. + * + * @param ctx The context of the channel close notification. + */ + @Override + public void channelInactive(ChannelHandlerContext ctx) throws Exception { + IOUtils.cleanup(LOG, bufferResponseDecoder, nonBufferResponseDecoder); + frameHeaderBuffer.release(); + + super.channelInactive(ctx); + } + + @Override + public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception { + if (!(msg instanceof ByteBuf)) { + ctx.fireChannelRead(msg); + return; + } + + ByteBuf data = (ByteBuf) msg; + try { + while (data.isReadable()) { + if (currentDecoder != null) { + NettyMessageDecoder.DecodingResult result = currentDecoder.onChannelRead(data); + if (!result.isFinished()) { + break; + } + ctx.fireChannelRead(result.getMessage()); + + currentDecoder = null; + frameHeaderBuffer.clear(); + } + + decodeFrameHeader(data); + } + checkState(!data.isReadable(), "Not all data of the received buffer consumed."); + } finally { + data.release(); + } + } + + private void decodeFrameHeader(ByteBuf data) { + ByteBuf toDecode = ByteBufUtils.accumulate( Review comment: Fixed the variable name. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: us...@infra.apache.org With regards, Apache Git Services
