/*
* The MIT License
*
* Copyright (c) 2009 The Broad Institute
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
package htsjdk.samtools.fastq;
import htsjdk.samtools.SAMException;
import htsjdk.samtools.util.IOUtil;
import htsjdk.samtools.util.StringUtil;
import java.io.BufferedReader;
import java.io.Closeable;
import java.io.File;
import java.io.IOException;
import java.util.Iterator;
import java.util.NoSuchElementException;
/**
* Reads a FASTQ file with four lines per record.
* WARNING: Despite the fact that this class implements Iterable, calling iterator() method does not
* start iteration from the beginning of the file. Developers should probably not call iterator()
* directly. It is provided so that this class can be used in Java for-each loop.
*/
public class FastqReader implements Iterator<FastqRecord>, Iterable<FastqRecord>, Closeable {
final private File fastqFile;
final private BufferedReader reader;
private FastqRecord nextRecord;
private int line=1;
final private boolean skipBlankLines;
public FastqReader(final File file) {
this(file,false);
}
/**
* Constructor
* @param file of FASTQ to read read. Will be opened with htsjdk.samtools.util.IOUtil.openFileForBufferedReading
* @param skipBlankLines should we skip blank lines ?
*/
public FastqReader(final File file, final boolean skipBlankLines) {
this.skipBlankLines=skipBlankLines;
fastqFile = file;
reader = IOUtil.openFileForBufferedReading(fastqFile);
nextRecord = readNextRecord();
}
public FastqReader(final BufferedReader reader) {
this(null, reader);
}
/**
* Constructor
* @param file Name of FASTQ being read, or null if not known.
* @param reader input reader . Will be closed by the close method
* @param skipBlankLines should we skip blank lines ?
*/
public FastqReader(final File file, final BufferedReader reader,boolean skipBlankLines) {
this.fastqFile = file;
this.reader = reader;
this.nextRecord = readNextRecord();
this.skipBlankLines = skipBlankLines;
}
public FastqReader(final File file, final BufferedReader reader) {
this(file,reader,false);
}
private FastqRecord readNextRecord() {
try {
// Read sequence header
final String seqHeader = readLineConditionallySkippingBlanks();
if (seqHeader == null) return null ;
if (StringUtil.isBlank(seqHeader)) {
throw new SAMException(error("Missing sequence header"));
}
if (!seqHeader.startsWith(FastqConstants.SEQUENCE_HEADER)) {
throw new SAMException(error("Sequence header must start with "+ FastqConstants.SEQUENCE_HEADER+": "+seqHeader));
}
// Read sequence line
final String seqLine = readLineConditionallySkippingBlanks();
checkLine(seqLine,"sequence line");
// Read quality header
final String qualHeader = readLineConditionallySkippingBlanks();
checkLine(qualHeader,"quality header");
if (!qualHeader.startsWith(FastqConstants.QUALITY_HEADER)) {
throw new SAMException(error("Quality header must start with "+ FastqConstants.QUALITY_HEADER+": "+qualHeader));
}
// Read quality line
final String qualLine = readLineConditionallySkippingBlanks();
checkLine(qualLine,"quality line");
// Check sequence and quality lines are same length
if (seqLine.length() != qualLine.length()) {
throw new SAMException(error("Sequence and quality line must be the same length"));
}
final FastqRecord frec = new FastqRecord(seqHeader.substring(1, seqHeader.length()), seqLine,
qualHeader.substring(1, qualHeader.length()), qualLine);
line += 4 ;
return frec ;
} catch (IOException e) {
throw new SAMException(String.format("Error reading fastq '%s'", getAbsolutePath()), e);
}
}
public boolean hasNext() { return nextRecord != null; }
public FastqRecord next() {
if (!hasNext()) {
throw new NoSuchElementException("next() called when !hasNext()");
}
final FastqRecord rec = nextRecord;
nextRecord = readNextRecord();
return rec;
}
public void remove() { throw new UnsupportedOperationException("Unsupported operation"); }
/**
* WARNING: Despite the fact that this class implements Iterable, calling iterator() method does not
* start iteration from the beginning of the file. Developers should probably not call iterator()
* directly. It is provided so that this class can be used in Java for-each loop.
*/
public Iterator<FastqRecord> iterator() { return this; }
public int getLineNumber() { return line ; }
/**
* @return Name of FASTQ being read, or null if not known.
*/
public File getFile() { return fastqFile ; }
public void close() {
try {
reader.close();
} catch (IOException e) {
throw new SAMException("IO problem in fastq file "+getAbsolutePath(), e);
}
}
private void checkLine(final String line, final String kind) {
if (line == null) {
throw new SAMException(error("File is too short - missing "+kind+" line"));
}
if (StringUtil.isBlank(line)) {
throw new SAMException(error("Missing "+kind));
}
}
private String error(final String msg) {
return msg + " at line "+line+" in fastq "+getAbsolutePath();
}
private String getAbsolutePath() {
if (fastqFile == null) return "";
else return fastqFile.getAbsolutePath();
}
private String readLineConditionallySkippingBlanks() throws IOException {
String line;
do {
line = reader.readLine();
if (line == null) return line;
} while(skipBlankLines && StringUtil.isBlank(line));
return line;
}
@Override
public String toString() {
return "FastqReader["+(this.fastqFile == null?"":this.fastqFile)+ " Line:"+getLineNumber()+"]";
}
}