| /** |
| * 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.hadoop.mapreduce.lib.input; |
| |
| import java.io.IOException; |
| import java.io.DataInput; |
| import java.io.DataOutput; |
| |
| import org.apache.hadoop.mapreduce.InputFormat; |
| import org.apache.hadoop.mapreduce.InputSplit; |
| import org.apache.hadoop.mapreduce.TaskAttemptContext; |
| import org.apache.hadoop.classification.InterfaceAudience; |
| import org.apache.hadoop.classification.InterfaceStability; |
| import org.apache.hadoop.fs.Path; |
| import org.apache.hadoop.io.Text; |
| import org.apache.hadoop.io.Writable; |
| |
| /** A section of an input file. Returned by {@link |
| * InputFormat#getSplits(JobContext)} and passed to |
| * {@link InputFormat#createRecordReader(InputSplit,TaskAttemptContext)}. */ |
| @InterfaceAudience.Public |
| @InterfaceStability.Stable |
| public class FileSplit extends InputSplit implements Writable { |
| private Path file; |
| private long start; |
| private long length; |
| private String[] hosts; |
| |
| public FileSplit() {} |
| |
| /** Constructs a split with host information |
| * |
| * @param file the file name |
| * @param start the position of the first byte in the file to process |
| * @param length the number of bytes in the file to process |
| * @param hosts the list of hosts containing the block, possibly null |
| */ |
| public FileSplit(Path file, long start, long length, String[] hosts) { |
| this.file = file; |
| this.start = start; |
| this.length = length; |
| this.hosts = hosts; |
| } |
| |
| /** The file containing this split's data. */ |
| public Path getPath() { return file; } |
| |
| /** The position of the first byte in the file to process. */ |
| public long getStart() { return start; } |
| |
| /** The number of bytes in the file to process. */ |
| @Override |
| public long getLength() { return length; } |
| |
| @Override |
| public String toString() { return file + ":" + start + "+" + length; } |
| |
| //////////////////////////////////////////// |
| // Writable methods |
| //////////////////////////////////////////// |
| |
| @Override |
| public void write(DataOutput out) throws IOException { |
| Text.writeString(out, file.toString()); |
| out.writeLong(start); |
| out.writeLong(length); |
| } |
| |
| @Override |
| public void readFields(DataInput in) throws IOException { |
| file = new Path(Text.readString(in)); |
| start = in.readLong(); |
| length = in.readLong(); |
| hosts = null; |
| } |
| |
| @Override |
| public String[] getLocations() throws IOException { |
| if (this.hosts == null) { |
| return new String[]{}; |
| } else { |
| return this.hosts; |
| } |
| } |
| } |