1 // ***************************************************************************
2 // BamStandardIndex.cpp (c) 2010 Derek Barnett
3 // Marth Lab, Department of Biology, Boston College
4 // ---------------------------------------------------------------------------
5 // Last modified: 24 June 2011 (DB)
6 // ---------------------------------------------------------------------------
7 // Provides index operations for the standardized BAM index format (".bai")
8 // ***************************************************************************
10 #include <api/BamAlignment.h>
11 #include <api/internal/BamReader_p.h>
12 #include <api/internal/BamStandardIndex_p.h>
13 using namespace BamTools;
14 using namespace BamTools::Internal;
23 // static BamStandardIndex constants
24 const int BamStandardIndex::MAX_BIN = 37450; // =(8^6-1)/7+1
25 const int BamStandardIndex::BAM_LIDX_SHIFT = 14;
26 const string BamStandardIndex::BAI_EXTENSION = ".bai";
27 const char* const BamStandardIndex::BAI_MAGIC = "BAI\1";
28 const int BamStandardIndex::SIZEOF_ALIGNMENTCHUNK = sizeof(uint64_t)*2;
29 const int BamStandardIndex::SIZEOF_BINCORE = sizeof(uint32_t) + sizeof(int32_t);
30 const int BamStandardIndex::SIZEOF_LINEAROFFSET = sizeof(uint64_t);
33 BamStandardIndex::BamStandardIndex(Internal::BamReaderPrivate* reader)
36 , m_cacheMode(BamIndex::LimitedIndexCaching)
40 m_isBigEndian = BamTools::SystemIsBigEndian();
44 BamStandardIndex::~BamStandardIndex(void) {
48 bool BamStandardIndex::AdjustRegion(const BamRegion& region, uint32_t& begin, uint32_t& end) {
50 // retrieve references from reader
51 const RefVector& references = m_reader->GetReferenceData();
53 // make sure left-bound position is valid
54 if ( region.LeftPosition > references.at(region.LeftRefID).RefLength )
58 begin = (unsigned int)region.LeftPosition;
60 // if right bound specified AND left&right bounds are on same reference
61 // OK to use right bound position as region 'end'
62 if ( region.isRightBoundSpecified() && ( region.LeftRefID == region.RightRefID ) )
63 end = (unsigned int)region.RightPosition;
65 // otherwise, set region 'end' to last reference base
66 else end = (unsigned int)references.at(region.LeftRefID).RefLength - 1;
72 void BamStandardIndex::CalculateCandidateBins(const uint32_t& begin,
74 set<uint16_t>& candidateBins)
76 // initialize list, bin '0' is always a valid bin
77 candidateBins.insert(0);
79 // get rest of bins that contain this region
81 for (k = 1 + (begin>>26); k <= 1 + (end>>26); ++k) { candidateBins.insert(k); }
82 for (k = 9 + (begin>>23); k <= 9 + (end>>23); ++k) { candidateBins.insert(k); }
83 for (k = 73 + (begin>>20); k <= 73 + (end>>20); ++k) { candidateBins.insert(k); }
84 for (k = 585 + (begin>>17); k <= 585 + (end>>17); ++k) { candidateBins.insert(k); }
85 for (k = 4681 + (begin>>14); k <= 4681 + (end>>14); ++k) { candidateBins.insert(k); }
88 bool BamStandardIndex::CalculateCandidateOffsets(const BaiReferenceSummary& refSummary,
89 const uint64_t& minOffset,
90 set<uint16_t>& candidateBins,
91 vector<int64_t>& offsets)
93 // attempt seek to first bin
94 if ( !Seek(refSummary.FirstBinFilePosition, SEEK_SET) )
97 // iterate over reference bins
99 int32_t numAlignmentChunks;
100 set<uint16_t>::iterator candidateBinIter;
101 for ( int i = 0; i < refSummary.NumBins; ++i ) {
103 // read bin contents (if successful, alignment chunks are now in m_buffer)
104 if ( !ReadBinIntoBuffer(binId, numAlignmentChunks) )
107 // see if bin is a 'candidate bin'
108 candidateBinIter = candidateBins.find(binId);
110 // if not, move on to next bin
111 if ( candidateBinIter == candidateBins.end() )
114 // otherwise, check bin's contents against for overlap
117 unsigned int offset = 0;
121 // iterate over alignment chunks
122 for (int j = 0; j < numAlignmentChunks; ++j ) {
124 // read chunk start & stop from buffer
125 memcpy((char*)&chunkStart, m_buffer+offset, sizeof(uint64_t));
126 offset += sizeof(uint64_t);
127 memcpy((char*)&chunkStop, m_buffer+offset, sizeof(uint64_t));
128 offset += sizeof(uint64_t);
130 // swap endian-ness if necessary
131 if ( m_isBigEndian ) {
132 SwapEndian_64(chunkStart);
133 SwapEndian_64(chunkStop);
136 // store alignment chunk's start offset
137 // if its stop offset is larger than our 'minOffset'
138 if ( chunkStop >= minOffset )
139 offsets.push_back(chunkStart);
142 // 'pop' bin ID from candidate bins set
143 candidateBins.erase(candidateBinIter);
145 // quit if no more candidates
146 if ( candidateBins.empty() )
155 uint64_t BamStandardIndex::CalculateMinOffset(const BaiReferenceSummary& refSummary,
156 const uint32_t& begin)
158 // if no linear offsets exist, return 0
159 if ( refSummary.NumLinearOffsets == 0 )
162 // if 'begin' starts beyond last linear offset, use the last linear offset as minimum
163 // else use the offset corresponding to the requested start position
164 const int shiftedBegin = begin>>BamStandardIndex::BAM_LIDX_SHIFT;
165 if ( shiftedBegin >= refSummary.NumLinearOffsets )
166 return LookupLinearOffset( refSummary, refSummary.NumLinearOffsets-1 );
168 return LookupLinearOffset( refSummary, shiftedBegin );
171 void BamStandardIndex::CheckBufferSize(char*& buffer,
172 unsigned int& bufferLength,
173 const unsigned int& requestedBytes)
176 if ( requestedBytes > bufferLength ) {
177 bufferLength = requestedBytes + 10;
179 buffer = new char[bufferLength];
181 } catch ( std::bad_alloc ) {
182 cerr << "BamStandardIndex ERROR: out of memory when allocating "
183 << requestedBytes << " byes" << endl;
188 void BamStandardIndex::CheckBufferSize(unsigned char*& buffer,
189 unsigned int& bufferLength,
190 const unsigned int& requestedBytes)
193 if ( requestedBytes > bufferLength ) {
194 bufferLength = requestedBytes + 10;
196 buffer = new unsigned char[bufferLength];
198 } catch ( std::bad_alloc ) {
199 cerr << "BamStandardIndex ERROR: out of memory when allocating "
200 << requestedBytes << " byes" << endl;
205 bool BamStandardIndex::CheckMagicNumber(void) {
207 // check 'magic number' to see if file is BAI index
209 size_t elementsRead = fread(magic, sizeof(char), 4, m_indexStream);
210 if ( elementsRead != 4 ) {
211 cerr << "BamStandardIndex ERROR: could not read format 'magic number'" << endl;
215 // compare to expected value
216 if ( strncmp(magic, BamStandardIndex::BAI_MAGIC, 4) != 0 ) {
217 cerr << "BamStandardIndex ERROR: invalid format" << endl;
225 void BamStandardIndex::ClearReferenceEntry(BaiReferenceEntry& refEntry) {
227 refEntry.Bins.clear();
228 refEntry.LinearOffsets.clear();
231 void BamStandardIndex::CloseFile(void) {
235 fclose(m_indexStream);
237 // clear index file summary data
238 m_indexFileSummary.clear();
240 // clean up I/O buffer
246 // builds index from associated BAM file & writes out to index file
247 bool BamStandardIndex::Create(void) {
249 // return false if BamReader is invalid or not open
250 if ( m_reader == 0 || !m_reader->IsOpen() ) {
251 cerr << "BamStandardIndex ERROR: BamReader is not open"
252 << ", aborting index creation" << endl;
257 if ( !m_reader->Rewind() ) {
258 cerr << "BamStandardIndex ERROR: could not rewind BamReader to create index"
259 << ", aborting index creation" << endl;
263 // open new index file (read & write)
264 string indexFilename = m_reader->Filename() + Extension();
265 if ( !OpenFile(indexFilename, "w+b") ) {
266 cerr << "BamStandardIndex ERROR: could not open ouput index file: " << indexFilename
267 << ", aborting index creation" << endl;
271 // initialize BaiFileSummary with number of references
272 const int& numReferences = m_reader->GetReferenceCount();
273 ReserveForSummary(numReferences);
275 // initialize output file
276 bool createdOk = true;
277 createdOk &= WriteHeader();
279 // set up bin, ID, offset, & coordinate markers
280 const uint32_t defaultValue = 0xffffffffu;
281 uint32_t currentBin = defaultValue;
282 uint32_t lastBin = defaultValue;
283 int32_t currentRefID = defaultValue;
284 int32_t lastRefID = defaultValue;
285 uint64_t currentOffset = (uint64_t)m_reader->Tell();
286 uint64_t lastOffset = currentOffset;
287 int32_t lastPosition = defaultValue;
289 // iterate through alignments in BAM file
291 BaiReferenceEntry refEntry;
292 while ( m_reader->LoadNextAlignment(al) ) {
294 // changed to new reference
295 if ( lastRefID != al.RefID ) {
297 // if not first reference, save previous reference data
298 if ( lastRefID != (int32_t)defaultValue ) {
300 SaveAlignmentChunkToBin(refEntry.Bins, currentBin, currentOffset, lastOffset);
301 createdOk &= WriteReferenceEntry(refEntry);
302 ClearReferenceEntry(refEntry);
304 // write any empty references between (but *NOT* including) lastRefID & al.RefID
305 for ( int i = lastRefID+1; i < al.RefID; ++i ) {
306 BaiReferenceEntry emptyEntry(i);
307 createdOk &= WriteReferenceEntry(emptyEntry);
310 // update bin markers
311 currentOffset = lastOffset;
314 currentRefID = al.RefID;
318 // write any empty references up to (but *NOT* including) al.RefID
320 for ( int i = 0; i < al.RefID; ++i ) {
321 BaiReferenceEntry emptyEntry(i);
322 createdOk &= WriteReferenceEntry(emptyEntry);
326 // update reference markers
327 refEntry.ID = al.RefID;
328 lastRefID = al.RefID;
329 lastBin = defaultValue;
332 // if lastPosition greater than current alignment position - file not sorted properly
333 else if ( lastPosition > al.Position ) {
334 cerr << "BamStandardIndex ERROR: BAM file is not properly sorted by coordinate"
335 << ", aborting index creation"
337 << "At alignment: " << al.Name
338 << " : previous position " << lastPosition
339 << " > this alignment position " << al.Position
340 << " on reference id: " << al.RefID << endl;
344 // if alignment's ref ID is valid & its bin is not a 'leaf'
345 if ( (al.RefID >= 0) && (al.Bin < 4681) )
346 SaveLinearOffsetEntry(refEntry.LinearOffsets, al.Position, al.GetEndPosition(), lastOffset);
348 // changed to new BAI bin
349 if ( al.Bin != lastBin ) {
351 // if not first bin on reference, save previous bin data
352 if ( currentBin != defaultValue )
353 SaveAlignmentChunkToBin(refEntry.Bins, currentBin, currentOffset, lastOffset);
356 currentOffset = lastOffset;
359 currentRefID = al.RefID;
361 // if invalid RefID, break out
362 if ( currentRefID < 0 )
366 // make sure that current file pointer is beyond lastOffset
367 if ( m_reader->Tell() <= (int64_t)lastOffset ) {
368 cerr << "BamStandardIndex ERROR: calculating offsets failed"
369 << ", aborting index creation" << endl;
373 // update lastOffset & lastPosition
374 lastOffset = m_reader->Tell();
375 lastPosition = al.Position;
378 // after finishing alignments, if any data was read, check:
379 if ( currentRefID >= 0 ) {
381 // store last alignment chunk to its bin, then write last reference entry with data
382 SaveAlignmentChunkToBin(refEntry.Bins, currentBin, currentOffset, lastOffset);
383 createdOk &= WriteReferenceEntry(refEntry);
385 // then write any empty references remaining at end of file
386 for ( int i = currentRefID+1; i < numReferences; ++i ) {
387 BaiReferenceEntry emptyEntry(i);
388 createdOk &= WriteReferenceEntry(emptyEntry);
392 // rewind reader now that we're done building
393 createdOk &= m_reader->Rewind();
399 // returns format's file extension
400 const string BamStandardIndex::Extension(void) {
401 return BamStandardIndex::BAI_EXTENSION;
404 bool BamStandardIndex::GetOffset(const BamRegion& region, int64_t& offset, bool* hasAlignmentsInRegion) {
406 // cannot calculate offsets if unknown/invalid reference ID requested
407 if ( region.LeftRefID < 0 || region.LeftRefID >= (int)m_indexFileSummary.size() )
410 // retrieve index summary for left bound reference
411 const BaiReferenceSummary& refSummary = m_indexFileSummary.at(region.LeftRefID);
413 // set up region boundaries based on actual BamReader data
416 if ( !AdjustRegion(region, begin, end) ) {
417 cerr << "BamStandardIndex ERROR: cannot calculate offsets on invalid region" << endl;
421 // retrieve all candidate bin IDs for region
422 set<uint16_t> candidateBins;
423 CalculateCandidateBins(begin, end, candidateBins);
425 // use reference's linear offsets to calculate the minimum offset
426 // that must be considered to find overlap
427 const uint64_t& minOffset = CalculateMinOffset(refSummary, begin);
429 // attempt to use reference summary, minOffset, & candidateBins to calculate offsets
430 // no data should not be error
431 vector<int64_t> offsets;
432 if ( !CalculateCandidateOffsets(refSummary, minOffset, candidateBins, offsets) ) {
433 cerr << "BamStandardIndex ERROR: could not calculate candidate offsets for requested region" << endl;
437 // ensure that offsets are sorted before processing
438 sort( offsets.begin(), offsets.end() );
440 // binary search for an overlapping block (may not be first one though)
442 typedef vector<int64_t>::const_iterator OffsetConstIterator;
443 OffsetConstIterator offsetFirst = offsets.begin();
444 OffsetConstIterator offsetIter = offsetFirst;
445 OffsetConstIterator offsetLast = offsets.end();
446 iterator_traits<OffsetConstIterator>::difference_type count = distance(offsetFirst, offsetLast);
447 iterator_traits<OffsetConstIterator>::difference_type step;
448 while ( count > 0 ) {
449 offsetIter = offsetFirst;
451 advance(offsetIter, step);
453 // attempt seek to candidate offset
454 const int64_t& candidateOffset = (*offsetIter);
455 if ( !m_reader->Seek(candidateOffset) ) {
456 cerr << "BamStandardIndex ERROR: could not jump"
457 << ", there was a problem seeking in BAM file" << endl;
461 // load first available alignment, setting flag to true if data exists
462 *hasAlignmentsInRegion = m_reader->LoadNextAlignment(al);
464 // check alignment against region
465 if ( al.GetEndPosition() < region.LeftPosition ) {
466 offsetFirst = ++offsetIter;
471 // seek back to the offset before the 'current offset' (to cover overlaps)
472 if ( offsetIter != offsets.begin() )
474 offset = (*offsetIter);
480 // returns whether reference has alignments or no
481 bool BamStandardIndex::HasAlignments(const int& referenceID) const {
482 if ( referenceID < 0 || referenceID >= (int)m_indexFileSummary.size() )
484 const BaiReferenceSummary& refSummary = m_indexFileSummary.at(referenceID);
485 return ( refSummary.NumBins > 0 );
488 bool BamStandardIndex::IsFileOpen(void) const {
489 return ( m_indexStream != 0 );
492 // attempts to use index data to jump to @region, returns success/fail
493 // a "successful" jump indicates no error, but not whether this region has data
494 // * thus, the method sets a flag to indicate whether there are alignments
495 // available after the jump position
496 bool BamStandardIndex::Jump(const BamRegion& region, bool* hasAlignmentsInRegion) {
499 *hasAlignmentsInRegion = false;
501 // skip if reader is not valid or is not open
502 if ( m_reader == 0 || !m_reader->IsOpen() )
505 // calculate nearest offset to jump to
507 if ( !GetOffset(region, offset, hasAlignmentsInRegion) ) {
508 cerr << "BamStandardIndex ERROR: could not jump"
509 << ", unable to calculate offset for specified region" << endl;
513 // if region has alignments, return success/fail of seeking there
514 if ( *hasAlignmentsInRegion )
515 return m_reader->Seek(offset);
517 // otherwise, simply return true (but hasAlignmentsInRegion flag has been set to false)
518 // (this is OK, BamReader will check this flag before trying to load data)
522 // loads existing data from file into memory
523 bool BamStandardIndex::Load(const std::string& filename) {
525 // attempt open index file (read-only)
526 if ( !OpenFile(filename, "rb") ) {
527 cerr << "BamStandardIndex ERROR: could not open input index file: " << filename
528 << ", aborting index load" << endl;
532 // if invalid format 'magic number', close & return failure
533 if ( !CheckMagicNumber() ) {
534 cerr << "BamStandardIndex ERROR: unexpected format for index file: " << filename
535 << ", aborting index load" << endl;
540 // attempt to load index file summary, return success/failure
541 if ( !SummarizeIndexFile() ) {
542 cerr << "BamStandardIndex ERROR: could not generate a summary of index file " << filename
543 << ", aborting index load" << endl;
548 // if we get here, index summary is loaded OK
552 uint64_t BamStandardIndex::LookupLinearOffset(const BaiReferenceSummary& refSummary, const int& index) {
554 // attempt seek to proper index file position
555 const int64_t linearOffsetFilePosition = (int64_t)refSummary.FirstLinearOffsetFilePosition +
556 index*BamStandardIndex::SIZEOF_LINEAROFFSET;
557 if ( !Seek(linearOffsetFilePosition, SEEK_SET) )
560 // read linear offset from BAI file
561 uint64_t linearOffset(0);
562 if ( !ReadLinearOffset(linearOffset) )
567 void BamStandardIndex::MergeAlignmentChunks(BaiAlignmentChunkVector& chunks) {
569 // skip if chunks are empty, nothing to merge
570 if ( chunks.empty() )
573 // set up merged alignment chunk container
574 BaiAlignmentChunkVector mergedChunks;
575 mergedChunks.push_back( chunks[0] );
577 // iterate over chunks
579 BaiAlignmentChunkVector::iterator chunkIter = chunks.begin();
580 BaiAlignmentChunkVector::iterator chunkEnd = chunks.end();
581 for ( ++chunkIter; chunkIter != chunkEnd; ++chunkIter) {
583 // get 'currentMergeChunk' based on numeric index
584 BaiAlignmentChunk& currentMergeChunk = mergedChunks[i];
586 // get sourceChunk based on source vector iterator
587 BaiAlignmentChunk& sourceChunk = (*chunkIter);
589 // if currentMergeChunk ends where sourceChunk starts, then merge the two
590 if ( currentMergeChunk.Stop>>16 == sourceChunk.Start>>16 )
591 currentMergeChunk.Stop = sourceChunk.Stop;
595 // append sourceChunk after currentMergeChunk
596 mergedChunks.push_back(sourceChunk);
598 // update i, so the next iteration will consider the
599 // recently-appended sourceChunk as new mergeChunk candidate
604 // saved newly-merged chunks into (parameter) chunks
605 chunks = mergedChunks;
608 bool BamStandardIndex::OpenFile(const std::string& filename, const char* mode) {
610 // make sure any previous index file is closed
613 // attempt to open file
614 m_indexStream = fopen(filename.c_str(), mode);
618 bool BamStandardIndex::ReadBinID(uint32_t& binId) {
619 size_t elementsRead = 0;
620 elementsRead += fread(&binId, sizeof(binId), 1, m_indexStream);
621 if ( m_isBigEndian ) SwapEndian_32(binId);
622 return ( elementsRead == 1 );
625 bool BamStandardIndex::ReadBinIntoBuffer(uint32_t& binId, int32_t& numAlignmentChunks) {
630 readOk &= ReadBinID(binId);
631 readOk &= ReadNumAlignmentChunks(numAlignmentChunks);
634 const unsigned int bytesRequested = numAlignmentChunks*BamStandardIndex::SIZEOF_ALIGNMENTCHUNK;
635 readOk &= ReadIntoBuffer(bytesRequested);
637 // return success/failure
641 bool BamStandardIndex::ReadIntoBuffer(const unsigned int& bytesRequested) {
643 // ensure that our buffer is big enough for request
644 BamStandardIndex::CheckBufferSize(m_buffer, m_bufferLength, bytesRequested);
646 // read from BAI file stream
647 size_t bytesRead = fread( m_buffer, sizeof(char), bytesRequested, m_indexStream );
648 return ( bytesRead == (size_t)bytesRequested );
651 bool BamStandardIndex::ReadLinearOffset(uint64_t& linearOffset) {
652 size_t elementsRead = 0;
653 elementsRead += fread(&linearOffset, sizeof(linearOffset), 1, m_indexStream);
654 if ( m_isBigEndian ) SwapEndian_64(linearOffset);
655 return ( elementsRead == 1 );
658 bool BamStandardIndex::ReadNumAlignmentChunks(int& numAlignmentChunks) {
659 size_t elementsRead = 0;
660 elementsRead += fread(&numAlignmentChunks, sizeof(numAlignmentChunks), 1, m_indexStream);
661 if ( m_isBigEndian ) SwapEndian_32(numAlignmentChunks);
662 return ( elementsRead == 1 );
665 bool BamStandardIndex::ReadNumBins(int& numBins) {
666 size_t elementsRead = 0;
667 elementsRead += fread(&numBins, sizeof(numBins), 1, m_indexStream);
668 if ( m_isBigEndian ) SwapEndian_32(numBins);
669 return ( elementsRead == 1 );
672 bool BamStandardIndex::ReadNumLinearOffsets(int& numLinearOffsets) {
673 size_t elementsRead = 0;
674 elementsRead += fread(&numLinearOffsets, sizeof(numLinearOffsets), 1, m_indexStream);
675 if ( m_isBigEndian ) SwapEndian_32(numLinearOffsets);
676 return ( elementsRead == 1 );
679 bool BamStandardIndex::ReadNumReferences(int& numReferences) {
680 size_t elementsRead = 0;
681 elementsRead += fread(&numReferences, sizeof(numReferences), 1, m_indexStream);
682 if ( m_isBigEndian ) SwapEndian_32(numReferences);
683 return ( elementsRead == 1 );
686 void BamStandardIndex::ReserveForSummary(const int& numReferences) {
687 m_indexFileSummary.clear();
688 m_indexFileSummary.assign( numReferences, BaiReferenceSummary() );
691 void BamStandardIndex::SaveAlignmentChunkToBin(BaiBinMap& binMap,
692 const uint32_t& currentBin,
693 const uint64_t& currentOffset,
694 const uint64_t& lastOffset)
696 // create new alignment chunk
697 BaiAlignmentChunk newChunk(currentOffset, lastOffset);
701 // if no entry exists yet for this bin, create one and store alignment chunk
702 BaiBinMap::iterator binIter = binMap.find(currentBin);
703 if ( binIter == binMap.end() ) {
704 BaiAlignmentChunkVector newChunks;
705 newChunks.push_back(newChunk);
706 binMap.insert( pair<uint32_t, BaiAlignmentChunkVector>(currentBin, newChunks));
709 // otherwise, just append alignment chunk
711 BaiAlignmentChunkVector& binChunks = (*binIter).second;
712 binChunks.push_back( newChunk );
716 void BamStandardIndex::SaveBinsSummary(const int& refId, const int& numBins) {
717 BaiReferenceSummary& refSummary = m_indexFileSummary.at(refId);
718 refSummary.NumBins = numBins;
719 refSummary.FirstBinFilePosition = Tell();
722 void BamStandardIndex::SaveLinearOffsetEntry(BaiLinearOffsetVector& offsets,
723 const int& alignmentStartPosition,
724 const int& alignmentStopPosition,
725 const uint64_t& lastOffset)
727 // get converted offsets
728 const int beginOffset = alignmentStartPosition >> BamStandardIndex::BAM_LIDX_SHIFT;
729 const int endOffset = (alignmentStopPosition - 1) >> BamStandardIndex::BAM_LIDX_SHIFT;
731 // resize vector if necessary
732 int oldSize = offsets.size();
733 int newSize = endOffset + 1;
734 if ( oldSize < newSize )
735 offsets.resize(newSize, 0);
738 for( int i = beginOffset + 1; i <= endOffset; ++i ) {
739 if ( offsets[i] == 0 )
740 offsets[i] = lastOffset;
744 void BamStandardIndex::SaveLinearOffsetsSummary(const int& refId, const int& numLinearOffsets) {
745 BaiReferenceSummary& refSummary = m_indexFileSummary.at(refId);
746 refSummary.NumLinearOffsets = numLinearOffsets;
747 refSummary.FirstLinearOffsetFilePosition = Tell();
750 // seek to position in index file stream
751 bool BamStandardIndex::Seek(const int64_t& position, const int& origin) {
752 return ( fseek64(m_indexStream, position, origin) == 0 );
755 // change the index caching behavior
756 void BamStandardIndex::SetCacheMode(const BamIndex::IndexCacheMode& mode) {
758 // do nothing else here ? cache mode will be ignored from now on, most likely
761 bool BamStandardIndex::SkipBins(const int& numBins) {
763 int32_t numAlignmentChunks;
764 bool skippedOk = true;
765 for (int i = 0; i < numBins; ++i)
766 skippedOk &= ReadBinIntoBuffer(binId, numAlignmentChunks); // results & buffer ignored
770 bool BamStandardIndex::SkipLinearOffsets(const int& numLinearOffsets) {
771 const unsigned int bytesRequested = numLinearOffsets*BamStandardIndex::SIZEOF_LINEAROFFSET;
772 return ReadIntoBuffer(bytesRequested);
775 void BamStandardIndex::SortLinearOffsets(BaiLinearOffsetVector& linearOffsets) {
776 sort( linearOffsets.begin(), linearOffsets.end() );
779 bool BamStandardIndex::SummarizeBins(BaiReferenceSummary& refSummary) {
781 // load number of bins
783 if ( !ReadNumBins(numBins) )
786 // store bins summary for this reference
787 refSummary.NumBins = numBins;
788 refSummary.FirstBinFilePosition = Tell();
790 // attempt skip reference bins, return success/failure
791 if ( !SkipBins(numBins) )
794 // if we get here, bin summarized OK
798 bool BamStandardIndex::SummarizeIndexFile(void) {
800 // load number of reference sequences
802 if ( !ReadNumReferences(numReferences) )
805 // initialize file summary data
806 ReserveForSummary(numReferences);
808 // iterate over reference entries
809 bool loadedOk = true;
810 BaiFileSummary::iterator summaryIter = m_indexFileSummary.begin();
811 BaiFileSummary::iterator summaryEnd = m_indexFileSummary.end();
812 for ( int i = 0; summaryIter != summaryEnd; ++summaryIter, ++i )
813 loadedOk &= SummarizeReference(*summaryIter);
819 bool BamStandardIndex::SummarizeLinearOffsets(BaiReferenceSummary& refSummary) {
821 // load number of linear offsets
822 int numLinearOffsets;
823 if ( !ReadNumLinearOffsets(numLinearOffsets) )
826 // store bin summary data for this reference
827 refSummary.NumLinearOffsets = numLinearOffsets;
828 refSummary.FirstLinearOffsetFilePosition = Tell();
830 // skip linear offsets in index file
831 if ( !SkipLinearOffsets(numLinearOffsets) )
834 // if get here, linear offsets summarized OK
838 bool BamStandardIndex::SummarizeReference(BaiReferenceSummary& refSummary) {
840 bool loadedOk = true;
841 loadedOk &= SummarizeBins(refSummary);
842 loadedOk &= SummarizeLinearOffsets(refSummary);
846 // return position of file pointer in index file stream
847 int64_t BamStandardIndex::Tell(void) const {
848 return ftell64(m_indexStream);
851 bool BamStandardIndex::WriteAlignmentChunk(const BaiAlignmentChunk& chunk) {
853 size_t elementsWritten = 0;
855 // localize alignment chunk offsets
856 uint64_t start = chunk.Start;
857 uint64_t stop = chunk.Stop;
859 // swap endian-ness if necessary
860 if ( m_isBigEndian ) {
861 SwapEndian_64(start);
865 // write to index file
866 elementsWritten += fwrite(&start, sizeof(start), 1, m_indexStream);
867 elementsWritten += fwrite(&stop, sizeof(stop), 1, m_indexStream);
869 // return success/failure of write
870 return ( elementsWritten == 2 );
873 bool BamStandardIndex::WriteAlignmentChunks(BaiAlignmentChunkVector& chunks) {
875 // make sure chunks are merged (simplified) before writing & saving summary
876 MergeAlignmentChunks(chunks);
878 size_t elementsWritten = 0;
881 int32_t chunkCount = chunks.size();
882 if ( m_isBigEndian ) SwapEndian_32(chunkCount);
883 elementsWritten += fwrite(&chunkCount, sizeof(chunkCount), 1, m_indexStream);
885 // iterate over chunks
886 bool chunksOk = true;
887 BaiAlignmentChunkVector::const_iterator chunkIter = chunks.begin();
888 BaiAlignmentChunkVector::const_iterator chunkEnd = chunks.end();
889 for ( ; chunkIter != chunkEnd; ++chunkIter )
890 chunksOk &= WriteAlignmentChunk( (*chunkIter) );
892 // return success/failure of write
893 return ( (elementsWritten == 1) && chunksOk );
896 bool BamStandardIndex::WriteBin(const uint32_t& binId, BaiAlignmentChunkVector& chunks) {
898 size_t elementsWritten = 0;
901 uint32_t binKey = binId;
902 if ( m_isBigEndian ) SwapEndian_32(binKey);
903 elementsWritten += fwrite(&binKey, sizeof(binKey), 1, m_indexStream);
905 // write bin's alignment chunks
906 bool chunksOk = WriteAlignmentChunks(chunks);
908 // return success/failure of write
909 return ( (elementsWritten == 1) && chunksOk );
912 bool BamStandardIndex::WriteBins(const int& refId, BaiBinMap& bins) {
914 size_t elementsWritten = 0;
916 // write number of bins
917 int32_t binCount = bins.size();
918 if ( m_isBigEndian ) SwapEndian_32(binCount);
919 elementsWritten += fwrite(&binCount, sizeof(binCount), 1, m_indexStream);
921 // save summary for reference's bins
922 SaveBinsSummary(refId, bins.size());
926 BaiBinMap::iterator binIter = bins.begin();
927 BaiBinMap::iterator binEnd = bins.end();
928 for ( ; binIter != binEnd; ++binIter )
929 binsOk &= WriteBin( (*binIter).first, (*binIter).second );
931 // return success/failure of write
932 return ( (elementsWritten == 1) && binsOk );
935 bool BamStandardIndex::WriteHeader(void) {
937 size_t elementsWritten = 0;
939 // write magic number
940 elementsWritten += fwrite(BamStandardIndex::BAI_MAGIC, sizeof(char), 4, m_indexStream);
942 // write number of reference sequences
943 int32_t numReferences = m_indexFileSummary.size();
944 if ( m_isBigEndian ) SwapEndian_32(numReferences);
945 elementsWritten += fwrite(&numReferences, sizeof(numReferences), 1, m_indexStream);
947 // return success/failure of write
948 return (elementsWritten == 5);
951 bool BamStandardIndex::WriteLinearOffsets(const int& refId, BaiLinearOffsetVector& linearOffsets) {
953 // make sure linear offsets are sorted before writing & saving summary
954 SortLinearOffsets(linearOffsets);
956 size_t elementsWritten = 0;
958 // write number of linear offsets
959 int32_t offsetCount = linearOffsets.size();
960 if ( m_isBigEndian ) SwapEndian_32(offsetCount);
961 elementsWritten += fwrite(&offsetCount, sizeof(offsetCount), 1, m_indexStream);
963 // save summary for reference's linear offsets
964 SaveLinearOffsetsSummary(refId, linearOffsets.size());
966 // iterate over linear offsets
967 BaiLinearOffsetVector::const_iterator offsetIter = linearOffsets.begin();
968 BaiLinearOffsetVector::const_iterator offsetEnd = linearOffsets.end();
969 for ( ; offsetIter != offsetEnd; ++offsetIter ) {
971 // write linear offset
972 uint64_t linearOffset = (*offsetIter);
973 if ( m_isBigEndian ) SwapEndian_64(linearOffset);
974 elementsWritten += fwrite(&linearOffset, sizeof(linearOffset), 1, m_indexStream);
977 // return success/failure of write
978 return ( elementsWritten == (size_t)(linearOffsets.size() + 1) );
981 bool BamStandardIndex::WriteReferenceEntry(BaiReferenceEntry& refEntry) {
983 refOk &= WriteBins(refEntry.ID, refEntry.Bins);
984 refOk &= WriteLinearOffsets(refEntry.ID, refEntry.LinearOffsets);