content: /*
   * Copyright 1999-2018 Alibaba Group Holding Ltd.
   *
   * Licensed 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 com.alibaba.csp.sentinel.cluster.server.codec.netty;
  
  import com.alibaba.csp.sentinel.cluster.ClusterConstants;
  import com.alibaba.csp.sentinel.cluster.codec.EntityWriter;
  import com.alibaba.csp.sentinel.cluster.codec.response.ResponseEntityWriter;
  import com.alibaba.csp.sentinel.cluster.response.ClusterResponse;
  import com.alibaba.csp.sentinel.cluster.response.Response;
  import com.alibaba.csp.sentinel.cluster.server.codec.ServerEntityCodecProvider;
  import com.alibaba.csp.sentinel.cluster.server.codec.registry.ResponseDataWriterRegistry;
  import com.alibaba.csp.sentinel.log.RecordLog;
  
  import io.netty.buffer.ByteBuf;
  import io.netty.channel.ChannelHandlerContext;
  import io.netty.handler.codec.MessageToByteEncoder;
  
  /**
   * @author Eric Zhao
   * @since 1.4.0
   */
  public class NettyResponseEncoder extends MessageToByteEncoder<ClusterResponse> {
  
      @Override
      protected void encode(ChannelHandlerContext ctx, ClusterResponse response, ByteBuf out) throws Exception {
          ResponseEntityWriter<ClusterResponse, ByteBuf> responseEntityWriter = ServerEntityCodecProvider.getResponseEntityWriter();
          if (responseEntityWriter == null) {
              RecordLog.warn("[NettyResponseEncoder] Cannot resolve the global response entity writer, reply bad status");
              writeBadStatusHead(response, out);
              return;
          }
  
          responseEntityWriter.writeTo(response, out);
      }
  
  
      private void writeBadStatusHead(Response response, ByteBuf out) {
          out.writeInt(response.getId());
          out.writeByte(ClusterConstants.RESPONSE_STATUS_BAD);
          out.writeByte(response.getStatus());
      }
  }
  