/*
* The MIT License
*
* Copyright (c) 2012 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 picard.illumina.parser.readers;
import picard.PicardException;
import picard.util.UnsignedTypeUtil;
import java.io.File;
import java.nio.ByteBuffer;
import java.util.Iterator;
/**
* Illumina uses an algorithm described in "Theory of RTA" that determines whether or not a cluster passes filter("PF") or not.
* These values are written as sequential bytes to Filter Files. The structure of a filter file is as follows:
* Bytes 0-3 : 0
* Bytes 4-7 : unsigned int version
* Bytes 8-11 : unsigned int numClusters
*/
public class FilterFileReader implements Iterator<Boolean> {
/** Number of bytes in the files header that will be skipped by the iterator*/
private static final int HEADER_SIZE = 12;
/** Expected Version */
public final int EXPECTED_VERSION = 3;
/** Iterator over each cluster in the FilterFile */
private final BinaryFileIterator<Byte> bbIterator;
/** Version number found in the FilterFile, this should equal 3 */
public final int version;
/** The number of cluster's pf values stored in this file */
public final long numClusters;
/** Byte representing a cluster failing filter(not a PF read), we test this exactly at
* the moment but technically the standard may be to check only lowest significant bit */
private final static byte FailedFilter = 0x00;
/** Byte representing a cluster passing filter(a PF read), we test this exactly at
* the moment but technically the standard may be to check only lowest significant bit */
private final static byte PassedFilter = 0x01;
/** The index of the current cluster within the file*/
private int currentCluster;
public FilterFileReader(final File file) {
bbIterator = MMapBackedIteratorFactory.getByteIterator(HEADER_SIZE, file);
final ByteBuffer headerBuf = bbIterator.getHeaderBytes();
for(int i = 0; i < 4; i++) {
final byte b = headerBuf.get();
if(b != 0) {
throw new PicardException("The first four bytes of a Filter File should be 0 but byte " + i + " was " + b + " in file " + file.getAbsolutePath());
}
}
version = headerBuf.getInt();
if(version != EXPECTED_VERSION) {
throw new PicardException("Expected version is " + EXPECTED_VERSION + " but version found was " + version + " in file " + file.getAbsolutePath());
}
numClusters = UnsignedTypeUtil.uIntToLong(headerBuf.getInt());
bbIterator.assertTotalElementsEqual(numClusters);
currentCluster = 0;
}
public boolean hasNext() {
return currentCluster < numClusters;
}
public Boolean next() {
final byte value = bbIterator.next();
currentCluster += 1;
if(value == PassedFilter) {
return true;
} else if(value == FailedFilter) {
return false;
} else {
String hexVal = Integer.toHexString(value);
hexVal = (hexVal.length() < 2 ? "0x0" : "0x") + hexVal;
throw new PicardException("Didn't recognized PF Byte (" + hexVal + ")" + " for element (" + currentCluster + ") in file(" + bbIterator.getFile().getAbsolutePath() + ")");
}
}
public void skipRecords(final int numToSkip) {
bbIterator.skipElements(numToSkip);
}
public void remove() {
throw new UnsupportedOperationException();
}
}