/*
* 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 htsjdk.variant.variantcontext.writer;
import htsjdk.samtools.SAMSequenceDictionary;
import htsjdk.tribble.index.IndexCreator;
import htsjdk.variant.variantcontext.VariantContext;
import htsjdk.variant.variantcontext.VariantContextBuilder;
import htsjdk.variant.vcf.VCFConstants;
import htsjdk.variant.vcf.VCFEncoder;
import htsjdk.variant.vcf.VCFHeader;
import htsjdk.variant.vcf.VCFHeaderLine;
import htsjdk.variant.vcf.VCFHeaderVersion;
import java.io.BufferedWriter;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.IOException;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.Writer;
/**
* this class writes VCF files
*/
class VCFWriter extends IndexingVariantContextWriter {
private static final String VERSION_LINE =
VCFHeader.METADATA_INDICATOR + VCFHeaderVersion.VCF4_1.getFormatString() + "=" + VCFHeaderVersion.VCF4_1.getVersionString();
// Initialized when the header is written to the output stream
private VCFEncoder vcfEncoder = null;
// the VCF header we're storing
protected VCFHeader mHeader = null;
private final boolean allowMissingFieldsInHeader;
// should we write genotypes or just sites?
private final boolean doNotWriteGenotypes;
// should we always output a complete format record, even if we could drop trailing fields?
private final boolean writeFullFormatField;
/*
* The VCF writer uses an internal Writer, based by the ByteArrayOutputStream lineBuffer,
* to temp. buffer the header and per-site output before flushing the per line output
* in one go to the super.getOutputStream. This results in high-performance, proper encoding,
* and allows us to avoid flushing explicitly the output stream getOutputStream, which
* allows us to properly compress vcfs in gz format without breaking indexing on the fly
* for uncompressed streams.
*/
private static final int INITIAL_BUFFER_SIZE = 1024 * 16;
private final ByteArrayOutputStream lineBuffer = new ByteArrayOutputStream(INITIAL_BUFFER_SIZE);
/* Wrapping in a {@link BufferedWriter} avoids frequent conversions with individual writes to OutputStreamWriter. */
private final Writer writer = new BufferedWriter(new OutputStreamWriter(lineBuffer, VCFEncoder.VCF_CHARSET));
public VCFWriter(final File location, final OutputStream output, final SAMSequenceDictionary refDict,
final boolean enableOnTheFlyIndexing,
final boolean doNotWriteGenotypes, final boolean allowMissingFieldsInHeader,
final boolean writeFullFormatField) {
super(writerName(location, output), location, output, refDict, enableOnTheFlyIndexing);
this.doNotWriteGenotypes = doNotWriteGenotypes;
this.allowMissingFieldsInHeader = allowMissingFieldsInHeader;
this.writeFullFormatField = writeFullFormatField;
}
public VCFWriter(final File location, final OutputStream output, final SAMSequenceDictionary refDict,
final IndexCreator indexCreator, final boolean enableOnTheFlyIndexing,
final boolean doNotWriteGenotypes, final boolean allowMissingFieldsInHeader,
final boolean writeFullFormatField) {
super(writerName(location, output), location, output, refDict, enableOnTheFlyIndexing, indexCreator);
this.doNotWriteGenotypes = doNotWriteGenotypes;
this.allowMissingFieldsInHeader = allowMissingFieldsInHeader;
this.writeFullFormatField = writeFullFormatField;
}
// --------------------------------------------------------------------------------
//
// VCFWriter interface functions
//
// --------------------------------------------------------------------------------
/*
* Write String s to the internal buffered writer.
*
* writeAndResetBuffer() must be called to actually write the data to the true output stream.
*
* @param s the string to write
* @throws IOException
*/
private void write(final String s) throws IOException {
writer.write(s);
}
/*
* Actually write the line buffer contents to the destination output stream. After calling this function
* the line buffer is reset so the contents of the buffer can be reused
*/
private void writeAndResetBuffer() throws IOException {
writer.flush();
getOutputStream().write(lineBuffer.toByteArray());
lineBuffer.reset();
}
@Override
public void writeHeader(final VCFHeader header) {
// note we need to update the mHeader object after this call because they header
// may have genotypes trimmed out of it, if doNotWriteGenotypes is true
try {
this.mHeader = writeHeader(header, writer, doNotWriteGenotypes, getVersionLine(), getStreamName());
this.vcfEncoder = new VCFEncoder(this.mHeader, this.allowMissingFieldsInHeader, this.writeFullFormatField);
writeAndResetBuffer();
} catch ( IOException e ) {
throw new RuntimeException("Couldn't write file " + getStreamName(), e);
}
}
public static String getVersionLine() {
return VERSION_LINE;
}
public static VCFHeader writeHeader(VCFHeader header,
final Writer writer,
final boolean doNotWriteGenotypes,
final String versionLine,
final String streamNameForError) {
header = doNotWriteGenotypes ? new VCFHeader(header.getMetaDataInSortedOrder()) : header;
try {
// the file format field needs to be written first
writer.write(versionLine + "\n");
for (final VCFHeaderLine line : header.getMetaDataInSortedOrder() ) {
if ( VCFHeaderVersion.isFormatString(line.getKey()) )
continue;
writer.write(VCFHeader.METADATA_INDICATOR);
writer.write(line.toString());
writer.write("\n");
}
// write out the column line
writer.write(VCFHeader.HEADER_INDICATOR);
boolean isFirst = true;
for (final VCFHeader.HEADER_FIELDS field : header.getHeaderFields() ) {
if ( isFirst )
isFirst = false; // don't write out a field separator
else
writer.write(VCFConstants.FIELD_SEPARATOR);
writer.write(field.toString());
}
if ( header.hasGenotypingData() ) {
writer.write(VCFConstants.FIELD_SEPARATOR);
writer.write("FORMAT");
for (final String sample : header.getGenotypeSamples() ) {
writer.write(VCFConstants.FIELD_SEPARATOR);
writer.write(sample);
}
}
writer.write("\n");
writer.flush(); // necessary so that writing to an output stream will work
}
catch (IOException e) {
throw new RuntimeException("IOException writing the VCF header to " + streamNameForError, e);
}
return header;
}
/**
* attempt to close the VCF file
*/
@Override
public void close() {
// try to close the vcf stream
try {
// TODO -- would it be useful to null out the line buffer so we don't have it around unnecessarily?
writer.close();
} catch (IOException e) {
throw new RuntimeException("Unable to close " + getStreamName(), e);
}
super.close();
}
/**
* Add a record to the file
*/
@Override
public void add(final VariantContext context) {
try {
super.add(context);
if (this.doNotWriteGenotypes) write(this.vcfEncoder.encode(new VariantContextBuilder(context).noGenotypes().make()));
else write(this.vcfEncoder.encode(context));
write("\n");
writeAndResetBuffer();
} catch (IOException e) {
throw new RuntimeException("Unable to write the VCF object to " + getStreamName(), e);
}
}
}