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.spark.network.client;
  
  import java.nio.ByteBuffer;
  import java.nio.channels.ClosedChannelException;
  
  import io.netty.buffer.ByteBuf;
  
  import org.apache.spark.network.util.TransportFrameDecoder;
  
  /**
   * An interceptor that is registered with the frame decoder to feed stream data to a
   * callback.
   */
  class StreamInterceptor implements TransportFrameDecoder.Interceptor {
  
    private final TransportResponseHandler handler;
    private final String streamId;
    private final long byteCount;
    private final StreamCallback callback;
    private long bytesRead;
  
    StreamInterceptor(
        TransportResponseHandler handler,
        String streamId,
        long byteCount,
        StreamCallback callback) {
      this.handler = handler;
      this.streamId = streamId;
      this.byteCount = byteCount;
      this.callback = callback;
      this.bytesRead = 0;
    }
  
    @Override
    public void exceptionCaught(Throwable cause) throws Exception {
      handler.deactivateStream();
      callback.onFailure(streamId, cause);
    }
  
    @Override
    public void channelInactive() throws Exception {
      handler.deactivateStream();
      callback.onFailure(streamId, new ClosedChannelException());
    }
  
    @Override
    public boolean handle(ByteBuf buf) throws Exception {
      int toRead = (int) Math.min(buf.readableBytes(), byteCount - bytesRead);
      ByteBuffer nioBuffer = buf.readSlice(toRead).nioBuffer();
  
      int available = nioBuffer.remaining();
      callback.onData(streamId, nioBuffer);
      bytesRead += available;
      if (bytesRead > byteCount) {
        RuntimeException re = new IllegalStateException(String.format(
          "Read too many bytes? Expected %d, but read %d.", byteCount, bytesRead));
        callback.onFailure(streamId, re);
        handler.deactivateStream();
        throw re;
      } else if (bytesRead == byteCount) {
        handler.deactivateStream();
        callback.onComplete(streamId);
      }
  
      return bytesRead != byteCount;
    }
  
  }
  