giraph-core/src/main/java/org/apache/giraph/utils/ExtendedDataOutput.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.giraph.utils;

import java.io.DataOutput;

/**
 * Add a few features to data output
 */
public interface ExtendedDataOutput extends DataOutput {
  /**
   * Ensure that backing byte structure has at least minSize
   * additional bytes
   *
   * @param minSize additional size required
   */
  void ensureWritable(int minSize);

  /**
   * Skip some number of bytes.
   *
   * @param  bytesToSkip Number of bytes to skip
   */
  void skipBytes(int bytesToSkip);

  /**
   * In order to write a size as a first part of an data output, it is
   * useful to be able to write an int at an arbitrary location in the stream
   *
   * @param pos Byte position in the output stream
   * @param value Value to write
   */
  void writeInt(int pos, int value);

  /**
   * Get the position in the output stream
   *
   * @return Position in the output stream
   */
  int getPos();

  /**
   * Get the internal byte array (if possible), read-only
   *
   * @return Internal byte array (do not modify)
   */
  byte[] getByteArray();

  /**
   * Copies the internal byte array
   *
   * @return Copied byte array
   */
  byte[] toByteArray();

  /**
   * Return a copy of slice of byte array
   *
   * @param offset offset of array
   * @param length length of slice
   * @return byte array
   */
  byte[] toByteArray(int offset, int length);

  /**
   * Clears the buffer
   */
  void reset();
}