    001    /**
    002     * Licensed to the Apache Software Foundation (ASF) under one
    003     * or more contributor license agreements.  See the NOTICE file
    004     * distributed with this work for additional information
    005     * regarding copyright ownership.  The ASF licenses this file
    006     * to you under the Apache License, Version 2.0 (the
    007     * "License"); you may not use this file except in compliance
    008     * with the License.  You may obtain a copy of the License at
    009     *
    010     *     http://www.apache.org/licenses/LICENSE-2.0
    011     *
    012     * Unless required by applicable law or agreed to in writing, software
    013     * distributed under the License is distributed on an "AS IS" BASIS,
    014     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    015     * See the License for the specific language governing permissions and
    016     * limitations under the License.
    017     */
    018
    019    package org.apache.hadoop.mapreduce;
    020
    021    import java.io.IOException;
    022
    023    import org.apache.hadoop.classification.InterfaceAudience;
    024    import org.apache.hadoop.classification.InterfaceStability;
    025    import org.apache.hadoop.mapreduce.InputFormat;
    026    import org.apache.hadoop.mapreduce.Mapper;
    027    import org.apache.hadoop.mapreduce.RecordReader;
    028
    029    /**
    030     * <code>InputSplit</code> represents the data to be processed by an
    031     * individual {@link Mapper}.
    032     *
    033     * <p>Typically, it presents a byte-oriented view on the input and is the
    034     * responsibility of {@link RecordReader} of the job to process this and present
    035     * a record-oriented view.
    036     *
    037     * @see InputFormat
    038     * @see RecordReader
    039     */
    040    @InterfaceAudience.Public
    041    @InterfaceStability.Stable
    042    public abstract class InputSplit {
    043      /**
    044       * Get the size of the split, so that the input splits can be sorted by size.
    045       * @return the number of bytes in the split
    046       * @throws IOException
    047       * @throws InterruptedException
    048       */
    049      public abstract long getLength() throws IOException, InterruptedException;
    050
    051      /**
    052       * Get the list of nodes by name where the data for the split would be local.
    053       * The locations do not need to be serialized.
    054       * @return a new array of the node nodes.
    055       * @throws IOException
    056       * @throws InterruptedException
    057       */
    058      public abstract
    059        String[] getLocations() throws IOException, InterruptedException;
    060    }