edu.iu.common.MultiFileSplit.java Source code

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Here is the source code for edu.iu.common.MultiFileSplit.java

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/*
 * Copyright 2014 Indiana University
 * 
 * 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 edu.iu.common;

import java.io.DataInput;
import java.io.DataOutput;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.io.Writable;
import org.apache.hadoop.mapreduce.InputSplit;

public class MultiFileSplit extends InputSplit implements Writable {

    private List<Path> files;
    private long length;
    private String[] hosts;

    MultiFileSplit() {
    }

    /**
     * Constructs a split with host information
     * 
     * @param file The file name
     * @param length The number of bytes in the file to process
     * @param hosts The list of hosts containing the block, possibly null
     */
    public MultiFileSplit(List<Path> files, long length, String[] hosts) {
        this.files = files;
        this.length = length;
        this.hosts = hosts;
    }

    public List<Path> getPathList() {
        return files;
    }

    @Override
    public void write(DataOutput out) throws IOException {
        out.writeInt(files.size());
        for (Path file : files) {
            Text.writeString(out, file.toString());
        }
        out.writeLong(length);
    }

    @Override
    public void readFields(DataInput in) throws IOException {
        int size = in.readInt();
        files = new ArrayList<Path>(size);
        for (int i = 0; i < size; i++) {
            Path file = new Path(Text.readString(in));
            files.add(file);
        }
        length = in.readLong();
        hosts = null;
    }

    @Override
    public long getLength() throws IOException, InterruptedException {
        return length;
    }

    @Override
    public String[] getLocations() throws IOException, InterruptedException {
        if (this.hosts == null) {
            return new String[] {};
        } else {
            return this.hosts;
        }
    }
}