giraph-core/src/main/java/org/apache/giraph/utils/ByteStructVertexIdMessageIterator.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 org.apache.hadoop.io.Writable;
import org.apache.hadoop.io.WritableComparable;

/**
 * Special iterator that reuses vertex ids and message objects so that the
 * lifetime of the object is only until next() is called.
 *
 * @param <I> vertexId type parameter
 * @param <M> message type parameter
 */
public class ByteStructVertexIdMessageIterator<I extends WritableComparable,
  M extends Writable> extends ByteStructVertexIdDataIterator<I, M>
  implements VertexIdMessageIterator<I, M> {

  /**
   * Constructor with vertexIdData
   *
   * @param vertexIdData vertexIdData
   */
  public ByteStructVertexIdMessageIterator(
    AbstractVertexIdData<I, M> vertexIdData) {
    super(vertexIdData);
  }

  @Override
  public M getCurrentMessage() {
    return getCurrentData();
  }

  @Override
  public int getCurrentMessageSize() {
    return getCurrentDataSize();
  }

  @Override
  public boolean isNewMessage() {
    return true;
  }
}