tajo-storage/tajo-storage-common/src/main/java/org/apache/tajo/storage/LocalFileInputChannel.java

/**
 * 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.tajo.storage;

import org.apache.hadoop.io.IOUtils;

import java.io.FileInputStream;
import java.io.IOException;
import java.nio.ByteBuffer;
import java.nio.channels.FileChannel;

/**
 * LocalFileInputChannel is a FileChannel wrapper of seek ability
 */
public final class LocalFileInputChannel extends SeekableInputChannel {
  private FileInputStream fileInputStream;
  private FileChannel channel;
  private long size;

  public LocalFileInputChannel(FileInputStream fileInputStream) throws IOException {
    this.fileInputStream = fileInputStream;
    this.channel = fileInputStream.getChannel();
    this.size = channel.size();
  }

  @Override
  public int read(ByteBuffer dst) throws IOException {
    return channel.read(dst);
  }

  @Override
  public void seek(long offset) throws IOException {
    this.channel.position(offset);
  }

  @Override
  public long position() throws IOException {
    return channel.position();
  }

  @Override
  public long size() throws IOException {
    return size;
  }

  @Override
  protected void implCloseChannel() throws IOException {
    IOUtils.cleanup(null, channel, fileInputStream);
  }
}