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.worker.block.io;
  
  import alluxio.worker.block.meta.BlockMeta;
  
  import java.io.IOException;
  
  /**
   * A local block reader used by block store.
   * It provides integration with the {@link BlockStreamTracker}.
   */
  public class StoreBlockReader extends LocalFileBlockReader {
    /** Session Id for the reader. */
    private final long mSessionId;
    /** Block meta for the reader. */
    private final BlockMeta mBlockMeta;
  
    /**
     * Creates new block reader for block store.
     *
     * @param sessionId session id
     * @param blockMeta block meta
     * @throws IOException
     */
    public StoreBlockReader(long sessionId, BlockMeta blockMeta) throws IOException {
      super(blockMeta.getPath());
      mSessionId = sessionId;
      mBlockMeta = blockMeta;
      if (mSessionId > 0) {
        BlockStreamTracker.readerOpened(this, mBlockMeta.getBlockLocation());
      }
    }
  
    @Override
    public void close() throws IOException {
      if (mSessionId > 0) {
        BlockStreamTracker.readerClosed(this, mBlockMeta.getBlockLocation());
      }
      super.close();
    }
  }
  