/**
* 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.hama.ml.regression;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
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.DoubleWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.io.compress.CompressionCodec;
import org.apache.hadoop.io.compress.CompressionCodecFactory;
import org.apache.hama.bsp.*;
import org.apache.hama.ml.math.DenseDoubleVector;
import org.apache.hama.ml.math.DoubleVector;
import org.apache.hama.ml.writable.VectorWritable;
import java.io.IOException;
import java.io.InputStream;
/**
* A {@link FileInputFormat} for files containing one vector and one double per
* line
*/
public class VectorDoubleFileInputFormat extends
FileInputFormat<VectorWritable, DoubleWritable> {
@Override
public RecordReader<VectorWritable, DoubleWritable> getRecordReader(
InputSplit split, BSPJob job) throws IOException {
return new VectorDoubleRecorderReader(job.getConfiguration(), (FileSplit) split);
}
static class VectorDoubleRecorderReader implements
RecordReader<VectorWritable, DoubleWritable> {
private static final Log LOG = LogFactory
.getLog(VectorDoubleRecorderReader.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.
*/
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 VectorDoubleRecorderReader(Configuration job, FileSplit split)
throws IOException {
this.maxLineLength = job.getInt("bsp.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(Integer.MAX_VALUE, end - start));
}
this.pos = start;
}
public VectorDoubleRecorderReader(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 VectorDoubleRecorderReader(InputStream in, long offset,
long endOffset, Configuration job) throws IOException {
this.maxLineLength = job.getInt("bsp.linerecordreader.maxlength",
Integer.MAX_VALUE);
this.in = new LineReader(in, job);
this.start = offset;
this.pos = offset;
this.end = endOffset;
}
@Override
public VectorWritable createKey() {
return new VectorWritable();
}
@Override
public DoubleWritable createValue() {
return new DoubleWritable();
}
/**
* Read a line.
*/
@Override
public synchronized boolean next(VectorWritable key, DoubleWritable value)
throws IOException {
while (pos < end) {
Text textVal = new Text();
int newSize = in.readLine(textVal, maxLineLength, Math.max(
(int) Math.min(Integer.MAX_VALUE, end - pos), maxLineLength));
if (newSize == 0) {
return false;
}
String[] kv = new String(textVal.getBytes()).split("\\>");
if (kv.length != 2) {
throw new IOException("a line was not parsed correctly");
}
value.set(Double.valueOf(kv[0]));
key.set(toDoubleVector(kv[1]));
if (LOG.isDebugEnabled()) {
LOG.info("reading " + kv[1] + ":" + kv[0]);
}
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;
}
private DoubleVector toDoubleVector(String s) {
String[] split = s.split(" ");
double[] dar = new double[split.length];
for (int i = 0; i < split.length; i++) {
dar[i] = Double.valueOf(split[i]);
}
return new DenseDoubleVector(dar);
}
/**
* Get the progress within the split
*/
@Override
public float getProgress() {
if (start == end) {
return 0.0f;
} else {
return Math.min(1.0f, (pos - start) / (float) (end - start));
}
}
@Override
public synchronized long getPos() throws IOException {
return pos;
}
@Override
public synchronized void close() throws IOException {
if (in != null) {
in.close();
}
}
}
}