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.util;
  
  import java.nio.ByteBuffer;
  import java.nio.channels.WritableByteChannel;
  
  /**
   * A writable channel that stores the written data in a byte array in memory.
   */
  public class ByteArrayWritableChannel implements WritableByteChannel {
  
    private final byte[] data;
    private int offset;
  
    public ByteArrayWritableChannel(int size) {
      this.data = new byte[size];
    }
  
    public byte[] getData() {
      return data;
    }
  
    public int length() {
      return offset;
    }
  
    /** Resets the channel so that writing to it will overwrite the existing buffer. */
    public void reset() {
      offset = 0;
    }
  
    /**
     * Reads from the given buffer into the internal byte array.
     */
    @Override
    public int write(ByteBuffer src) {
      int toTransfer = Math.min(src.remaining(), data.length - offset);
      src.get(data, offset, toTransfer);
      offset += toTransfer;
      return toTransfer;
    }
  
    @Override
    public void close() {
  
    }
  
    @Override
    public boolean isOpen() {
      return true;
    }
  
  }
  