content: /*
   *
   * 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.proto;
  
  import io.netty.buffer.ByteBuf;
  import io.netty.channel.ChannelHandlerContext;
  import io.netty.channel.ChannelInboundHandlerAdapter;
  import io.netty.channel.group.ChannelGroup;
  import java.nio.channels.ClosedChannelException;
  import lombok.extern.slf4j.Slf4j;
  import org.apache.bookkeeper.conf.ServerConfiguration;
  import org.apache.bookkeeper.processor.RequestProcessor;
  
  /**
   * Serverside handler for bookkeeper requests.
   */
  @Slf4j
  public class BookieRequestHandler extends ChannelInboundHandlerAdapter {
  
      private static final int DEFAULT_PENDING_RESPONSE_SIZE = 256;
  
      private final RequestProcessor requestProcessor;
      private final ChannelGroup allChannels;
  
      private ChannelHandlerContext ctx;
  
      private ByteBuf pendingSendResponses = null;
      private int maxPendingResponsesSize = DEFAULT_PENDING_RESPONSE_SIZE;
  
      BookieRequestHandler(ServerConfiguration conf, RequestProcessor processor, ChannelGroup allChannels) {
          this.requestProcessor = processor;
          this.allChannels = allChannels;
      }
  
      public ChannelHandlerContext ctx() {
          return ctx;
      }
  
      @Override
      public void channelActive(ChannelHandlerContext ctx) throws Exception {
          log.info("Channel connected {}", ctx.channel());
          this.ctx = ctx;
          super.channelActive(ctx);
      }
  
      @Override
      public void channelRegistered(ChannelHandlerContext ctx) throws Exception {
          allChannels.add(ctx.channel());
      }
  
      @Override
      public void channelInactive(ChannelHandlerContext ctx) throws Exception {
          log.info("Channels disconnected: {}", ctx.channel());
      }
  
      @Override
      public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
          if (cause instanceof ClosedChannelException) {
              log.info("Client died before request could be completed on {}", ctx.channel(), cause);
              return;
          }
          log.error("Unhandled exception occurred in I/O thread or handler on {}", ctx.channel(), cause);
          ctx.close();
      }
  
      @Override
      public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
          if (!(msg instanceof BookkeeperProtocol.Request || msg instanceof BookieProtocol.Request)) {
              ctx.fireChannelRead(msg);
              return;
          }
          requestProcessor.processRequest(msg, this);
      }
  
      public synchronized void prepareSendResponseV2(int rc, BookieProtocol.ParsedAddRequest req) {
          if (pendingSendResponses == null) {
              pendingSendResponses = ctx().alloc().directBuffer(maxPendingResponsesSize);
          }
          BookieProtoEncoding.ResponseEnDeCoderPreV3.serializeAddResponseInto(rc, req, pendingSendResponses);
      }
  
      public synchronized void flushPendingResponse() {
          if (pendingSendResponses != null) {
              maxPendingResponsesSize = (int) Math.max(
                      maxPendingResponsesSize * 0.5 + 0.5 * pendingSendResponses.readableBytes(),
                      DEFAULT_PENDING_RESPONSE_SIZE);
              if (ctx().channel().isActive()) {
                  ctx().writeAndFlush(pendingSendResponses, ctx.voidPromise());
              } else {
                  pendingSendResponses.release();
              }
              pendingSendResponses = null;
          }
      }
  }
  