1 // ***************************************************************************
2 // BamMultiReader.cpp (c) 2010 Erik Garrison
3 // Marth Lab, Department of Biology, Boston College
4 // All rights reserved.
5 // ---------------------------------------------------------------------------
6 // Last modified: 23 Februrary 2010 (EG)
7 // ---------------------------------------------------------------------------
8 // Uses BGZF routines were adapted from the bgzf.c code developed at the Broad
10 // ---------------------------------------------------------------------------
11 // Functionality for simultaneously reading multiple BAM files.
13 // This functionality allows applications to work on very large sets of files
14 // without requiring intermediate merge, sort, and index steps for each file
15 // subset. It also improves the performance of our merge system as it
16 // precludes the need to sort merged files.
17 // ***************************************************************************
29 #include "BamMultiReader.h"
30 using namespace BamTools;
33 // -----------------------------------------------------
34 // BamMultiReader implementation
35 // -----------------------------------------------------
38 BamMultiReader::BamMultiReader(void)
44 BamMultiReader::~BamMultiReader(void) {
45 Close(); // close the bam files
46 // clean up reader objects
47 for (vector<pair<BamReader*, BamAlignment*> >::iterator it = readers.begin(); it != readers.end(); ++it) {
53 // close the BAM files
54 void BamMultiReader::Close(void) {
55 for (vector<pair<BamReader*, BamAlignment*> >::iterator it = readers.begin(); it != readers.end(); ++it) {
56 BamReader* reader = it->first;
57 reader->Close(); // close the reader
61 // updates the reference id stored in the BamMultiReader
62 // to reflect the current state of the readers
63 void BamMultiReader::UpdateReferenceID(void) {
64 // the alignments are sorted by position, so the first alignment will always have the lowest reference ID
65 if (alignments.begin()->second.second->RefID != CurrentRefID) {
66 // get the next reference id
67 // while there aren't any readers at the next ref id
68 // increment the ref id
69 int nextRefID = CurrentRefID;
70 while (alignments.begin()->second.second->RefID != nextRefID) {
73 //cerr << "updating reference id from " << CurrentRefID << " to " << nextRefID << endl;
74 CurrentRefID = nextRefID;
78 // checks if any readers still have alignments
79 bool BamMultiReader::HasOpenReaders() {
80 return alignments.size() > 0;
83 // get next alignment among all files
84 bool BamMultiReader::GetNextAlignment(BamAlignment& nextAlignment) {
86 // bail out if we are at EOF in all files, means no more alignments to process
87 if (!HasOpenReaders())
90 // when all alignments have stepped into a new target sequence, update our
91 // current reference sequence id
94 // our lowest alignment and reader will be at the front of our alignment index
95 BamAlignment* alignment = alignments.begin()->second.second;
96 BamReader* reader = alignments.begin()->second.first;
98 // now that we have the lowest alignment in the set, save it by copy to our argument
99 nextAlignment = BamAlignment(*alignment);
101 // remove this alignment index entry from our alignment index
102 alignments.erase(alignments.begin());
104 // and add another entry if we can get another alignment from the reader
105 if (reader->GetNextAlignment(*alignment)) {
106 alignments.insert(make_pair(make_pair(alignment->RefID, alignment->Position),
107 make_pair(reader, alignment)));
108 } else { // do nothing
109 //cerr << "reached end of file " << lowestReader->GetFilename() << endl;
116 // get next alignment among all files without parsing character data from alignments
117 bool BamMultiReader::GetNextAlignmentCore(BamAlignment& nextAlignment) {
119 // bail out if we are at EOF in all files, means no more alignments to process
120 if (!HasOpenReaders())
123 // when all alignments have stepped into a new target sequence, update our
124 // current reference sequence id
127 // our lowest alignment and reader will be at the front of our alignment index
128 BamAlignment* alignment = alignments.begin()->second.second;
129 BamReader* reader = alignments.begin()->second.first;
131 // now that we have the lowest alignment in the set, save it by copy to our argument
132 nextAlignment = BamAlignment(*alignment);
133 //memcpy(&nextAlignment, alignment, sizeof(BamAlignment));
135 // remove this alignment index entry from our alignment index
136 alignments.erase(alignments.begin());
138 // and add another entry if we can get another alignment from the reader
139 if (reader->GetNextAlignmentCore(*alignment)) {
140 alignments.insert(make_pair(make_pair(alignment->RefID, alignment->Position),
141 make_pair(reader, alignment)));
142 } else { // do nothing
143 //cerr << "reached end of file " << lowestReader->GetFilename() << endl;
150 // jumps to specified region(refID, leftBound) in BAM files, returns success/fail
151 bool BamMultiReader::Jump(int refID, int position) {
153 //if ( References.at(refID).RefHasAlignments && (position <= References.at(refID).RefLength) ) {
154 CurrentRefID = refID;
155 CurrentLeft = position;
158 for (vector<pair<BamReader*, BamAlignment*> >::iterator it = readers.begin(); it != readers.end(); ++it) {
159 BamReader* reader = it->first;
160 result &= reader->Jump(refID, position);
162 cerr << "ERROR: could not jump " << reader->GetFilename() << " to " << refID << ":" << position << endl;
169 for (vector<pair<BamReader*, BamAlignment*> >::iterator it = readers.begin(); it != readers.end(); ++it) {
170 BamReader* br = it->first;
171 BamAlignment* ba = it->second;
172 if (br->GetNextAlignment(*ba)) {
173 alignments.insert(make_pair(make_pair(ba->RefID, ba->Position),
176 // assume BamReader EOF
184 void BamMultiReader::Open(const vector<string> filenames, bool openIndexes, bool coreMode) {
185 // for filename in filenames
186 fileNames = filenames; // save filenames in our multireader
187 for (vector<string>::const_iterator it = filenames.begin(); it != filenames.end(); ++it) {
188 string filename = *it;
189 BamReader* reader = new BamReader;
191 reader->Open(filename, filename + ".bai");
193 reader->Open(filename); // for merging, jumping is disallowed
195 BamAlignment* alignment = new BamAlignment;
197 reader->GetNextAlignmentCore(*alignment);
199 reader->GetNextAlignment(*alignment);
201 readers.push_back(make_pair(reader, alignment)); // store pointers to our readers for cleanup
202 alignments.insert(make_pair(make_pair(alignment->RefID, alignment->Position),
203 make_pair(reader, alignment)));
208 void BamMultiReader::PrintFilenames(void) {
209 for (vector<pair<BamReader*, BamAlignment*> >::iterator it = readers.begin(); it != readers.end(); ++it) {
210 BamReader* reader = it->first;
211 cout << reader->GetFilename() << endl;
216 void BamMultiReader::DumpAlignmentIndex(void) {
217 for (AlignmentIndex::const_iterator it = alignments.begin(); it != alignments.end(); ++it) {
218 cerr << it->first.first << ":" << it->first.second << " " << it->second.first->GetFilename() << endl;
222 // returns BAM file pointers to beginning of alignment data
223 bool BamMultiReader::Rewind(void) {
225 for (vector<pair<BamReader*, BamAlignment*> >::iterator it = readers.begin(); it != readers.end(); ++it) {
226 BamReader* reader = it->first;
227 result &= reader->Rewind();
232 // saves index data to BAM index files (".bai") where necessary, returns success/fail
233 bool BamMultiReader::CreateIndexes(void) {
235 for (vector<pair<BamReader*, BamAlignment*> >::iterator it = readers.begin(); it != readers.end(); ++it) {
236 BamReader* reader = it->first;
237 result &= reader->CreateIndex();
242 // makes a virtual, unified header for all the bam files in the multireader
243 const string BamMultiReader::GetHeaderText(void) const {
245 string mergedHeader = "";
246 map<string, bool> readGroups;
248 // foreach extraction entry (each BAM file)
249 for (vector<pair<BamReader*, BamAlignment*> >::const_iterator rs = readers.begin(); rs != readers.end(); ++rs) {
251 map<string, bool> currentFileReadGroups;
253 BamReader* reader = rs->first;
255 stringstream header(reader->GetHeaderText());
256 vector<string> lines;
258 while (getline(header, item))
259 lines.push_back(item);
261 for (vector<string>::const_iterator it = lines.begin(); it != lines.end(); ++it) {
263 // get next line from header, skip if empty
264 string headerLine = *it;
265 if ( headerLine.empty() ) { continue; }
267 // if first file, save HD & SQ entries
268 if ( rs == readers.begin() ) {
269 if ( headerLine.find("@HD") == 0 || headerLine.find("@SQ") == 0) {
270 mergedHeader.append(headerLine.c_str());
271 mergedHeader.append(1, '\n');
275 // (for all files) append RG entries if they are unique
276 if ( headerLine.find("@RG") == 0 ) {
277 stringstream headerLineSs(headerLine);
278 string part, readGroupPart, readGroup;
279 while(std::getline(headerLineSs, part, '\t')) {
280 stringstream partSs(part);
282 std::getline(partSs, subtag, ':');
283 if (subtag == "ID") {
284 std::getline(partSs, readGroup, ':');
288 if (readGroups.find(readGroup) == readGroups.end()) { // prevents duplicate @RG entries
289 mergedHeader.append(headerLine.c_str() );
290 mergedHeader.append(1, '\n');
291 readGroups[readGroup] = true;
292 currentFileReadGroups[readGroup] = true;
294 // warn iff we are reading one file and discover duplicated @RG tags in the header
295 // otherwise, we emit no warning, as we might be merging multiple BAM files with identical @RG tags
296 if (currentFileReadGroups.find(readGroup) != currentFileReadGroups.end()) {
297 cerr << "WARNING: duplicate @RG tag " << readGroup
298 << " entry in header of " << reader->GetFilename() << endl;
305 // return merged header text
309 // ValidateReaders checks that all the readers point to BAM files representing
310 // alignments against the same set of reference sequences, and that the
311 // sequences are identically ordered. If these checks fail the operation of
312 // the multireader is undefined, so we force program exit.
313 void BamMultiReader::ValidateReaders(void) const {
314 int firstRefCount = readers.front().first->GetReferenceCount();
315 BamTools::RefVector firstRefData = readers.front().first->GetReferenceData();
316 for (vector<pair<BamReader*, BamAlignment*> >::const_iterator it = readers.begin(); it != readers.end(); ++it) {
317 BamReader* reader = it->first;
318 BamTools::RefVector currentRefData = reader->GetReferenceData();
319 BamTools::RefVector::const_iterator f = firstRefData.begin();
320 BamTools::RefVector::const_iterator c = currentRefData.begin();
321 if (reader->GetReferenceCount() != firstRefCount || firstRefData.size() != currentRefData.size()) {
322 cerr << "ERROR: mismatched number of references in " << reader->GetFilename()
323 << " expected " << firstRefCount
324 << " reference sequences but only found " << reader->GetReferenceCount() << endl;
327 // this will be ok; we just checked above that we have identically-sized sets of references
328 // here we simply check if they are all, in fact, equal in content
329 while (f != firstRefData.end()) {
330 if (f->RefName != c->RefName || f->RefLength != c->RefLength) {
331 cerr << "ERROR: mismatched references found in " << reader->GetFilename()
332 << " expected: " << endl;
333 for (BamTools::RefVector::const_iterator a = firstRefData.begin(); a != firstRefData.end(); ++a)
334 cerr << a->RefName << " " << a->RefLength << endl;
335 cerr << "but found: " << endl;
336 for (BamTools::RefVector::const_iterator a = currentRefData.begin(); a != currentRefData.end(); ++a)
337 cerr << a->RefName << " " << a->RefLength << endl;
345 // NB: The following functions assume that we have identical references for all
346 // BAM files. We enforce this by invoking the above validation function
347 // (ValidateReaders) to verify that our reference data is the same across all
348 // files on Open, so we will not encounter a situation in which there is a
349 // mismatch and we are still live.
351 // returns the number of reference sequences
352 const int BamMultiReader::GetReferenceCount(void) const {
353 return readers.front().first->GetReferenceCount();
356 // returns vector of reference objects
357 const BamTools::RefVector BamMultiReader::GetReferenceData(void) const {
358 return readers.front().first->GetReferenceData();
361 const int BamMultiReader::GetReferenceID(const string& refName) const {
362 return readers.front().first->GetReferenceID(refName);