alluxio-master-2.x/core/client/fs/src/main/java/alluxio/client/file/FileOutStream.java
/*
 * 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.file;

import alluxio.annotation.PublicApi;
import alluxio.client.Cancelable;

import java.io.IOException;
import java.io.OutputStream;
import javax.annotation.concurrent.NotThreadSafe;

/**
 * An abstraction of the output stream API in Alluxio to write data to a file or a block. In
 * addition to extending abstract class {@link OutputStream} as the basics, it also keeps counting
 * the number of bytes written to the output stream, and extends {@link Cancelable} to abort the
 * writes.
 */
@PublicApi
@NotThreadSafe
public abstract class FileOutStream extends OutputStream implements Cancelable {
  /** The number of bytes written. */
  protected long mBytesWritten = 0;

  /**
   * @return the number of bytes written to this stream
   */
  public long getBytesWritten() {
    return mBytesWritten;
  }

  /**
   * Aborts the output stream.
   */
  @Override
  public void cancel() throws IOException {}
}
