/** * Copyright 2005 The Apache Software Foundation * * Licensed 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.hadoop.mapred;import java.io.IOException;import org.apache.hadoop.io.*;/** Protocol that a reduce task uses to retrieve output data from a map task's * tracker. */ interface MapOutputProtocol {  /** Returns the output from the named map task destined for this partition.*/  MapOutputFile getFile(String mapTaskId, String reduceTaskId,                        IntWritable partition) throws IOException;}