/**
* 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.mapred;
import java.io.IOException;
import java.io.InputStream;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FSDataInputStream;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.io.compress.CompressionCodec;
import org.apache.hadoop.io.compress.CompressionCodecFactory;
import org.apache.commons.logging.LogFactory;
import org.apache.commons.logging.Log;
/**
* Treats keys as offset in file and value as line.
* @deprecated Use
* {@link org.apache.hadoop.mapreduce.lib.input.LineRecordReader} instead.
*/
@Deprecated
public class LineRecordReader implements RecordReader<LongWritable, Text> {
private static final Log LOG
= LogFactory.getLog(LineRecordReader.class.getName());
private CompressionCodecFactory compressionCodecs = null;
private long start;
private long pos;
private long end;
private LineReader in;
int maxLineLength;
/**
* A class that provides a line reader from an input stream.
* @deprecated Use {@link org.apache.hadoop.util.LineReader} instead.
*/
@Deprecated
public static class LineReader extends org.apache.hadoop.util.LineReader {
LineReader(InputStream in) {
super(in);
}
LineReader(InputStream in, int bufferSize) {
super(in, bufferSize);
}
public LineReader(InputStream in, Configuration conf) throws IOException {
super(in, conf);
}
}
public LineRecordReader(Configuration job,
FileSplit split) throws IOException {
this.maxLineLength = job.getInt("mapred.linerecordreader.maxlength",
Integer.MAX_VALUE);
start = split.getStart();
end = start + split.getLength();
final Path file = split.getPath();
compressionCodecs = new CompressionCodecFactory(job);
final CompressionCodec codec = compressionCodecs.getCodec(file);
// open the file and seek to the start of the split
FileSystem fs = file.getFileSystem(job);
FSDataInputStream fileIn = fs.open(split.getPath());
boolean skipFirstLine = false;
if (codec != null) {
in = new LineReader(codec.createInputStream(fileIn), job);
end = Long.MAX_VALUE;
} else {
if (start != 0) {
skipFirstLine = true;
--start;
fileIn.seek(start);
}
in = new LineReader(fileIn, job);
}
if (skipFirstLine) { // skip first line and re-establish "start".
start += in.readLine(new Text(), 0,
(int)Math.min((long)Integer.MAX_VALUE, end - start));
}
this.pos = start;
}
public LineRecordReader(InputStream in, long offset, long endOffset,
int maxLineLength) {
this.maxLineLength = maxLineLength;
this.in = new LineReader(in);
this.start = offset;
this.pos = offset;
this.end = endOffset;
}
public LineRecordReader(InputStream in, long offset, long endOffset,
Configuration job)
throws IOException{
this.maxLineLength = job.getInt("mapred.linerecordreader.maxlength",
Integer.MAX_VALUE);
this.in = new LineReader(in, job);
this.start = offset;
this.pos = offset;
this.end = endOffset;
}
public LongWritable createKey() {
return new LongWritable();
}
public Text createValue() {
return new Text();
}
/** Read a line. */
public synchronized boolean next(LongWritable key, Text value)
throws IOException {
while (pos < end) {
key.set(pos);
int newSize = in.readLine(value, maxLineLength,
Math.max((int)Math.min(Integer.MAX_VALUE, end-pos),
maxLineLength));
if (newSize == 0) {
return false;
}
pos += newSize;
if (newSize < maxLineLength) {
return true;
}
// line too long. try again
LOG.info("Skipped line of size " + newSize + " at pos " + (pos - newSize));
}
return false;
}
/**
* Get the progress within the split
*/
public float getProgress() {
if (start == end) {
return 0.0f;
} else {
return Math.min(1.0f, (pos - start) / (float)(end - start));
}
}
public synchronized long getPos() throws IOException {
return pos;
}
public synchronized void close() throws IOException {
if (in != null) {
in.close();
}
}
}