/*
    * 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.bsp;
  
  import java.io.DataInput;
  import java.io.DataOutput;
  import java.io.IOException;
  
  import org.apache.hadoop.io.Writable;
  import org.apache.hadoop.mapreduce.InputSplit;
  
  /**
   * This InputSplit will not give any ordering or location data.
   * It is used internally by BspInputFormat (which determines
   * how many tasks to run the application on).  Users should not use this
   * directly.
   */
  public class BspInputSplit extends InputSplit implements Writable {
    /** Number of splits */
    private int numSplits = -1;
    /** Split index */
    private int splitIndex = -1;
  
    /**
     * Reflection constructor.
     */
    public BspInputSplit() { }
  
    /**
     * Constructor used by {@link BspInputFormat}.
     *
     * @param splitIndex Index of this split.
     * @param numSplits Total number of splits.
     */
    public BspInputSplit(int splitIndex, int numSplits) {
      this.splitIndex = splitIndex;
      this.numSplits = numSplits;
    }
  
    @Override
    public long getLength() throws IOException, InterruptedException {
      return 0;
    }
  
    @Override
    public String[] getLocations() throws IOException, InterruptedException {
      return new String[]{};
    }
  
    @Override
    public void readFields(DataInput in) throws IOException {
      splitIndex = in.readInt();
      numSplits = in.readInt();
    }
  
    @Override
    public void write(DataOutput out) throws IOException {
      out.writeInt(splitIndex);
      out.writeInt(numSplits);
    }
  
    /**
     * Get the index of this split.
     *
     * @return Index of this split.
     */
    public int getSplitIndex() {
      return splitIndex;
    }
  
    /**
     * Get the number of splits for this application.
     *
     * @return Total number of splits.
     */
    public int getNumSplits() {
      return numSplits;
    }
  
    @Override
    public String toString() {
      return "'" + getClass().getCanonicalName() +
        ", index=" + getSplitIndex() + ", num=" + getNumSplits();
   }
 }