content: /*
   * The Alluxio Open Foundation licenses this work under the Apache License, version 2.0
   * (the "License"). You may not use this work except in compliance with the License, which is
   * available at www.apache.org/licenses/LICENSE-2.0
   *
   * This software is distributed on an "AS IS" basis, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
   * either express or implied, as more fully set forth in the License.
   *
   * See the NOTICE file distributed with this work for information regarding copyright ownership.
   */
  
  package alluxio.client.block.stream;
  
  import alluxio.network.protocol.databuffer.DataBuffer;
  import alluxio.network.protocol.databuffer.NioDataBuffer;
  
  import com.google.common.base.Preconditions;
  
  import java.io.IOException;
  import java.nio.ByteBuffer;
  import javax.annotation.Nullable;
  
  /**
   * A {@link DataReader} which serves data from a given byte array.
   */
  public class TestDataReader implements DataReader {
    private final byte[] mData;
    private long mPos;
    private long mEnd;
    private long mChunkSize;
    private boolean mClosed = false;
  
    public TestDataReader(byte[] data, long chunkSize, long offset, long length) {
      mData = data;
      mChunkSize = chunkSize;
      mPos = offset;
      mEnd = offset + length;
    }
  
    @Override
    @Nullable
    public DataBuffer readChunk() {
      Preconditions.checkState(!mClosed, "reader is closed");
      if (mPos >= mEnd || mPos >= mData.length) {
        return null;
      }
      int bytesToRead = (int) (Math.min(Math.min(mChunkSize, mEnd - mPos), mData.length - mPos));
      ByteBuffer buffer = ByteBuffer.wrap(mData, (int) mPos, bytesToRead);
      DataBuffer dataBuffer = new NioDataBuffer(buffer, buffer.remaining());
      mPos += dataBuffer.getLength();
      return dataBuffer;
    }
  
    @Override
    public long pos() {
      return mPos;
    }
  
    @Override
    public void close() {
      mClosed = true;
    }
  
    public boolean isClosed() {
      return mClosed;
    }
  
    public static class Factory implements DataReader.Factory {
      long mChunkSize;
      byte[] mData;
      TestDataReader mReader;
  
      public Factory(long chunkSize, byte[] data) {
        mChunkSize = chunkSize;
        mData = data;
      }
  
      @Override
      public DataReader create(long offset, long len) throws IOException {
        mReader = new TestDataReader(mData, mChunkSize, offset, len);
        return mReader;
      }
  
      @Override
      public void close() throws IOException {}
  
      public TestDataReader getDataReader() {
        return mReader;
      }
    }
  }
  