Fix lock held during getRef.
[lightning.git] / tilelib.go
1 package lightning
2
3 import (
4         "bufio"
5         "bytes"
6         "context"
7         "encoding/gob"
8         "fmt"
9         "io"
10         "os"
11         "regexp"
12         "runtime"
13         "sort"
14         "strings"
15         "sync"
16         "sync/atomic"
17
18         "github.com/klauspost/pgzip"
19         log "github.com/sirupsen/logrus"
20         "golang.org/x/crypto/blake2b"
21 )
22
23 type tileVariantID uint16 // 1-based
24
25 type tileLibRef struct {
26         Tag     tagID
27         Variant tileVariantID
28 }
29
30 type tileSeq map[string][]tileLibRef
31
32 func (tseq tileSeq) Variants() ([]tileVariantID, int, int) {
33         maxtag := 0
34         for _, refs := range tseq {
35                 for _, ref := range refs {
36                         if maxtag < int(ref.Tag) {
37                                 maxtag = int(ref.Tag)
38                         }
39                 }
40         }
41         vars := make([]tileVariantID, maxtag+1)
42         var kept, dropped int
43         for _, refs := range tseq {
44                 for _, ref := range refs {
45                         if vars[int(ref.Tag)] != 0 {
46                                 dropped++
47                         } else {
48                                 kept++
49                         }
50                         vars[int(ref.Tag)] = ref.Variant
51                 }
52         }
53         return vars, kept, dropped
54 }
55
56 type tileLibrary struct {
57         retainNoCalls       bool
58         skipOOO             bool
59         retainTileSequences bool
60
61         taglib         *tagLibrary
62         variant        [][][blake2b.Size256]byte
63         refseqs        map[string]map[string][]tileLibRef
64         compactGenomes map[string][]tileVariantID
65         // count [][]int
66         seq      map[[blake2b.Size256]byte][]byte
67         variants int64
68         // if non-nil, write out any tile variants added while tiling
69         encoder *gob.Encoder
70
71         mtx   sync.RWMutex
72         vlock []sync.Locker
73 }
74
75 func (tilelib *tileLibrary) loadTagSet(newtagset [][]byte) error {
76         // Loading a tagset means either passing it through to the
77         // output (if it's the first one we've seen), or just ensuring
78         // it doesn't disagree with what we already have.
79         if len(newtagset) == 0 {
80                 return nil
81         }
82         tilelib.mtx.Lock()
83         defer tilelib.mtx.Unlock()
84         if tilelib.taglib == nil || tilelib.taglib.Len() == 0 {
85                 tilelib.taglib = &tagLibrary{}
86                 err := tilelib.taglib.setTags(newtagset)
87                 if err != nil {
88                         return err
89                 }
90                 if tilelib.encoder != nil {
91                         err = tilelib.encoder.Encode(LibraryEntry{
92                                 TagSet: newtagset,
93                         })
94                         if err != nil {
95                                 return err
96                         }
97                 }
98         } else if tilelib.taglib.Len() != len(newtagset) {
99                 return fmt.Errorf("cannot merge libraries with differing tagsets")
100         } else {
101                 current := tilelib.taglib.Tags()
102                 for i := range newtagset {
103                         if !bytes.Equal(newtagset[i], current[i]) {
104                                 return fmt.Errorf("cannot merge libraries with differing tagsets")
105                         }
106                 }
107         }
108         return nil
109 }
110
111 func (tilelib *tileLibrary) loadTileVariants(tvs []TileVariant, variantmap map[tileLibRef]tileVariantID) error {
112         for _, tv := range tvs {
113                 // Assign a new variant ID (unique across all inputs)
114                 // for each input variant.
115                 variantmap[tileLibRef{Tag: tv.Tag, Variant: tv.Variant}] = tilelib.getRef(tv.Tag, tv.Sequence).Variant
116         }
117         return nil
118 }
119
120 func (tilelib *tileLibrary) loadCompactGenomes(cgs []CompactGenome, variantmap map[tileLibRef]tileVariantID, onLoadGenome func(CompactGenome)) error {
121         log.Debugf("loadCompactGenomes: %d", len(cgs))
122         var wg sync.WaitGroup
123         errs := make(chan error, 1)
124         for _, cg := range cgs {
125                 wg.Add(1)
126                 cg := cg
127                 go func() {
128                         defer wg.Done()
129                         for i, variant := range cg.Variants {
130                                 if len(errs) > 0 {
131                                         return
132                                 }
133                                 if variant == 0 {
134                                         continue
135                                 }
136                                 tag := tagID(i / 2)
137                                 newvariant, ok := variantmap[tileLibRef{Tag: tag, Variant: variant}]
138                                 if !ok {
139                                         err := fmt.Errorf("oops: genome %q has variant %d for tag %d, but that variant was not in its library", cg.Name, variant, tag)
140                                         select {
141                                         case errs <- err:
142                                         default:
143                                         }
144                                         return
145                                 }
146                                 log.Tracef("loadCompactGenomes: cg %s tag %d variant %d => %d", cg.Name, tag, variant, newvariant)
147                                 cg.Variants[i] = newvariant
148                         }
149                         if onLoadGenome != nil {
150                                 onLoadGenome(cg)
151                         }
152                         if tilelib.encoder != nil {
153                                 err := tilelib.encoder.Encode(LibraryEntry{
154                                         CompactGenomes: []CompactGenome{cg},
155                                 })
156                                 if err != nil {
157                                         select {
158                                         case errs <- err:
159                                         default:
160                                         }
161                                         return
162                                 }
163                         }
164                         if tilelib.compactGenomes != nil {
165                                 tilelib.mtx.Lock()
166                                 defer tilelib.mtx.Unlock()
167                                 tilelib.compactGenomes[cg.Name] = cg.Variants
168                         }
169                 }()
170         }
171         wg.Wait()
172         go close(errs)
173         return <-errs
174 }
175
176 func (tilelib *tileLibrary) loadCompactSequences(cseqs []CompactSequence, variantmap map[tileLibRef]tileVariantID) error {
177         log.Debugf("loadCompactSequences: %d", len(cseqs))
178         for _, cseq := range cseqs {
179                 for _, tseq := range cseq.TileSequences {
180                         for i, libref := range tseq {
181                                 if libref.Variant == 0 {
182                                         // No variant (e.g., import
183                                         // dropped tiles with
184                                         // no-calls) = no translation.
185                                         continue
186                                 }
187                                 v, ok := variantmap[libref]
188                                 if !ok {
189                                         return fmt.Errorf("oops: CompactSequence %q has variant %d for tag %d, but that variant was not in its library", cseq.Name, libref.Variant, libref.Tag)
190                                 }
191                                 tseq[i].Variant = v
192                         }
193                 }
194                 if tilelib.encoder != nil {
195                         if err := tilelib.encoder.Encode(LibraryEntry{
196                                 CompactSequences: []CompactSequence{cseq},
197                         }); err != nil {
198                                 return err
199                         }
200                 }
201         }
202         tilelib.mtx.Lock()
203         defer tilelib.mtx.Unlock()
204         if tilelib.refseqs == nil {
205                 tilelib.refseqs = map[string]map[string][]tileLibRef{}
206         }
207         for _, cseq := range cseqs {
208                 tilelib.refseqs[cseq.Name] = cseq.TileSequences
209         }
210         return nil
211 }
212
213 func (tilelib *tileLibrary) LoadDir(ctx context.Context, path string, onLoadGenome func(CompactGenome)) error {
214         var files []string
215         var walk func(string) error
216         walk = func(path string) error {
217                 f, err := open(path)
218                 if err != nil {
219                         return err
220                 }
221                 defer f.Close()
222                 fis, err := f.Readdir(-1)
223                 if err != nil {
224                         files = append(files, path)
225                         return nil
226                 }
227                 for _, fi := range fis {
228                         if fi.Name() == "." || fi.Name() == ".." {
229                                 continue
230                         } else if child := path + "/" + fi.Name(); fi.IsDir() {
231                                 err = walk(child)
232                                 if err != nil {
233                                         return err
234                                 }
235                         } else if strings.HasSuffix(child, ".gob") || strings.HasSuffix(child, ".gob.gz") {
236                                 files = append(files, child)
237                         }
238                 }
239                 return nil
240         }
241         log.Infof("LoadDir: walk dir %s", path)
242         err := walk(path)
243         if err != nil {
244                 return err
245         }
246         ctx, cancel := context.WithCancel(ctx)
247         defer cancel()
248         var mtx sync.Mutex
249         cgs := []CompactGenome{}
250         cseqs := []CompactSequence{}
251         variantmap := map[tileLibRef]tileVariantID{}
252         errs := make(chan error, len(files))
253         log.Infof("LoadDir: read %d files", len(files))
254         for _, path := range files {
255                 path := path
256                 go func() {
257                         f, err := open(path)
258                         if err != nil {
259                                 errs <- err
260                                 return
261                         }
262                         defer f.Close()
263                         defer log.Infof("LoadDir: finished reading %s", path)
264                         errs <- DecodeLibrary(f, strings.HasSuffix(path, ".gz"), func(ent *LibraryEntry) error {
265                                 if ctx.Err() != nil {
266                                         return ctx.Err()
267                                 }
268                                 if len(ent.TagSet) > 0 {
269                                         mtx.Lock()
270                                         if tilelib.taglib == nil || tilelib.taglib.Len() != len(ent.TagSet) {
271                                                 // load first set of tags, or
272                                                 // report mismatch if 2 sets
273                                                 // have different #tags.
274                                                 if err := tilelib.loadTagSet(ent.TagSet); err != nil {
275                                                         mtx.Unlock()
276                                                         return err
277                                                 }
278                                         }
279                                         mtx.Unlock()
280                                 }
281                                 variantmapadd := map[tileLibRef]tileVariantID{}
282                                 for _, tv := range ent.TileVariants {
283                                         variantmapadd[tileLibRef{Tag: tv.Tag, Variant: tv.Variant}] = tilelib.getRef(tv.Tag, tv.Sequence).Variant
284                                 }
285                                 mtx.Lock()
286                                 cgs = append(cgs, ent.CompactGenomes...)
287                                 cseqs = append(cseqs, ent.CompactSequences...)
288                                 for k, v := range variantmapadd {
289                                         variantmap[k] = v
290                                 }
291                                 mtx.Unlock()
292                                 return nil
293                         })
294                 }()
295         }
296         for range files {
297                 err := <-errs
298                 if err != nil {
299                         return err
300                 }
301         }
302         log.Info("LoadDir: loadCompactGenomes")
303         err = tilelib.loadCompactGenomes(cgs, variantmap, onLoadGenome)
304         if err != nil {
305                 return err
306         }
307         log.Info("LoadDir: loadCompactSequences")
308         err = tilelib.loadCompactSequences(cseqs, variantmap)
309         if err != nil {
310                 return err
311         }
312         log.Info("LoadDir done")
313         return nil
314 }
315
316 func (tilelib *tileLibrary) WriteDir(dir string) error {
317         nfiles := 128
318         files := make([]*os.File, nfiles)
319         for i := range files {
320                 f, err := os.OpenFile(fmt.Sprintf("%s/library.%04d.gob.gz", dir, i), os.O_CREATE|os.O_WRONLY, 0666)
321                 if err != nil {
322                         return err
323                 }
324                 defer f.Close()
325                 files[i] = f
326         }
327         bufws := make([]*bufio.Writer, nfiles)
328         for i := range bufws {
329                 bufws[i] = bufio.NewWriterSize(files[i], 1<<26)
330         }
331         zws := make([]*pgzip.Writer, nfiles)
332         for i := range zws {
333                 zws[i] = pgzip.NewWriter(bufws[i])
334                 defer zws[i].Close()
335         }
336         encoders := make([]*gob.Encoder, nfiles)
337         for i := range encoders {
338                 encoders[i] = gob.NewEncoder(zws[i])
339         }
340
341         log.Infof("WriteDir: writing %d files", nfiles)
342         ctx, cancel := context.WithCancel(context.Background())
343         defer cancel()
344         errs := make(chan error, nfiles)
345         for start := range files {
346                 start := start
347                 go func() {
348                         err := encoders[start].Encode(LibraryEntry{TagSet: tilelib.taglib.Tags()})
349                         if err != nil {
350                                 errs <- err
351                                 return
352                         }
353                         if start == 0 {
354                                 // For now, just write all the genomes and refs
355                                 // to the first file
356                                 for name, cg := range tilelib.compactGenomes {
357                                         err := encoders[start].Encode(LibraryEntry{CompactGenomes: []CompactGenome{{
358                                                 Name:     name,
359                                                 Variants: cg,
360                                         }}})
361                                         if err != nil {
362                                                 errs <- err
363                                                 return
364                                         }
365                                 }
366                                 for name, tseqs := range tilelib.refseqs {
367                                         err := encoders[start].Encode(LibraryEntry{CompactSequences: []CompactSequence{{
368                                                 Name:          name,
369                                                 TileSequences: tseqs,
370                                         }}})
371                                         if err != nil {
372                                                 errs <- err
373                                                 return
374                                         }
375                                 }
376                         }
377                         tvs := []TileVariant{}
378                         for tag := start; tag < len(tilelib.variant) && ctx.Err() == nil; tag += nfiles {
379                                 tvs = tvs[:0]
380                                 for idx, hash := range tilelib.variant[tag] {
381                                         tvs = append(tvs, TileVariant{
382                                                 Tag:      tagID(tag),
383                                                 Variant:  tileVariantID(idx + 1),
384                                                 Blake2b:  hash,
385                                                 Sequence: tilelib.seq[hash],
386                                         })
387                                 }
388                                 err := encoders[start].Encode(LibraryEntry{TileVariants: tvs})
389                                 if err != nil {
390                                         errs <- err
391                                         return
392                                 }
393                         }
394                         errs <- nil
395                 }()
396         }
397         for range files {
398                 err := <-errs
399                 if err != nil {
400                         return err
401                 }
402         }
403         log.Info("WriteDir: flushing")
404         for i := range zws {
405                 err := zws[i].Close()
406                 if err != nil {
407                         return err
408                 }
409                 err = bufws[i].Flush()
410                 if err != nil {
411                         return err
412                 }
413                 err = files[i].Close()
414                 if err != nil {
415                         return err
416                 }
417         }
418         log.Info("WriteDir: done")
419         return nil
420 }
421
422 // Load library data from rdr. Tile variants might be renumbered in
423 // the process; in that case, genomes variants will be renumbered to
424 // match.
425 //
426 // If onLoadGenome is non-nil, call it on each CompactGenome entry.
427 func (tilelib *tileLibrary) LoadGob(ctx context.Context, rdr io.Reader, gz bool, onLoadGenome func(CompactGenome)) error {
428         cgs := []CompactGenome{}
429         cseqs := []CompactSequence{}
430         variantmap := map[tileLibRef]tileVariantID{}
431         err := DecodeLibrary(rdr, gz, func(ent *LibraryEntry) error {
432                 if ctx.Err() != nil {
433                         return ctx.Err()
434                 }
435                 if err := tilelib.loadTagSet(ent.TagSet); err != nil {
436                         return err
437                 }
438                 if err := tilelib.loadTileVariants(ent.TileVariants, variantmap); err != nil {
439                         return err
440                 }
441                 cgs = append(cgs, ent.CompactGenomes...)
442                 cseqs = append(cseqs, ent.CompactSequences...)
443                 return nil
444         })
445         if err != nil {
446                 return err
447         }
448         if ctx.Err() != nil {
449                 return ctx.Err()
450         }
451         err = tilelib.loadCompactGenomes(cgs, variantmap, onLoadGenome)
452         if err != nil {
453                 return err
454         }
455         err = tilelib.loadCompactSequences(cseqs, variantmap)
456         if err != nil {
457                 return err
458         }
459         return nil
460 }
461
462 func (tilelib *tileLibrary) dump(out io.Writer) {
463         printTV := func(tag int, variant tileVariantID) {
464                 if variant < 1 {
465                         fmt.Fprintf(out, " -")
466                 } else if tag >= len(tilelib.variant) {
467                         fmt.Fprintf(out, " (!tag=%d)", tag)
468                 } else if int(variant) > len(tilelib.variant[tag]) {
469                         fmt.Fprintf(out, " (tag=%d,!variant=%d)", tag, variant)
470                 } else {
471                         fmt.Fprintf(out, " %x", tilelib.variant[tag][variant-1][:8])
472                 }
473         }
474         for refname, refseqs := range tilelib.refseqs {
475                 for seqname, seq := range refseqs {
476                         fmt.Fprintf(out, "ref %s %s", refname, seqname)
477                         for _, libref := range seq {
478                                 printTV(int(libref.Tag), libref.Variant)
479                         }
480                         fmt.Fprintf(out, "\n")
481                 }
482         }
483         for name, cg := range tilelib.compactGenomes {
484                 fmt.Fprintf(out, "cg %s", name)
485                 for tag, variant := range cg {
486                         printTV(tag/2, variant)
487                 }
488                 fmt.Fprintf(out, "\n")
489         }
490 }
491
492 type importStats struct {
493         InputFile              string
494         InputLabel             string
495         InputLength            int
496         InputCoverage          int
497         PathLength             int
498         DroppedOutOfOrderTiles int
499 }
500
501 func (tilelib *tileLibrary) TileFasta(filelabel string, rdr io.Reader, matchChromosome *regexp.Regexp) (tileSeq, []importStats, error) {
502         ret := tileSeq{}
503         type jobT struct {
504                 label string
505                 fasta []byte
506         }
507         todo := make(chan jobT, 1)
508         scanner := bufio.NewScanner(rdr)
509         go func() {
510                 defer close(todo)
511                 var fasta []byte
512                 var seqlabel string
513                 for scanner.Scan() {
514                         buf := scanner.Bytes()
515                         if len(buf) > 0 && buf[0] == '>' {
516                                 todo <- jobT{seqlabel, append([]byte(nil), fasta...)}
517                                 seqlabel, fasta = strings.SplitN(string(buf[1:]), " ", 2)[0], fasta[:0]
518                                 log.Debugf("%s %s reading fasta", filelabel, seqlabel)
519                         } else {
520                                 fasta = append(fasta, bytes.ToLower(buf)...)
521                         }
522                 }
523                 todo <- jobT{seqlabel, fasta}
524         }()
525         type foundtag struct {
526                 pos   int
527                 tagid tagID
528         }
529         found := make([]foundtag, 2000000)
530         path := make([]tileLibRef, 2000000)
531         totalFoundTags := 0
532         totalPathLen := 0
533         skippedSequences := 0
534         taglen := tilelib.taglib.TagLen()
535         var stats []importStats
536         for job := range todo {
537                 if len(job.fasta) == 0 {
538                         continue
539                 } else if !matchChromosome.MatchString(job.label) {
540                         skippedSequences++
541                         continue
542                 }
543                 log.Debugf("%s %s tiling", filelabel, job.label)
544
545                 found = found[:0]
546                 tilelib.taglib.FindAll(job.fasta, func(tagid tagID, pos, taglen int) {
547                         found = append(found, foundtag{pos: pos, tagid: tagid})
548                 })
549                 totalFoundTags += len(found)
550                 if len(found) == 0 {
551                         log.Warnf("%s %s no tags found", filelabel, job.label)
552                 }
553
554                 skipped := 0
555                 if tilelib.skipOOO {
556                         log.Infof("%s %s keeping longest increasing subsequence", filelabel, job.label)
557                         keep := longestIncreasingSubsequence(len(found), func(i int) int { return int(found[i].tagid) })
558                         for i, x := range keep {
559                                 found[i] = found[x]
560                         }
561                         skipped = len(found) - len(keep)
562                         found = found[:len(keep)]
563                 }
564
565                 log.Infof("%s %s getting %d librefs", filelabel, job.label, len(found))
566                 throttle := &throttle{Max: runtime.NumCPU()}
567                 path = path[:len(found)]
568                 var lowquality int64
569                 for i, f := range found {
570                         i, f := i, f
571                         throttle.Acquire()
572                         go func() {
573                                 defer throttle.Release()
574                                 var startpos, endpos int
575                                 if i == 0 {
576                                         startpos = 0
577                                 } else {
578                                         startpos = f.pos
579                                 }
580                                 if i == len(found)-1 {
581                                         endpos = len(job.fasta)
582                                 } else {
583                                         endpos = found[i+1].pos + taglen
584                                 }
585                                 path[i] = tilelib.getRef(f.tagid, job.fasta[startpos:endpos])
586                                 if countBases(job.fasta[startpos:endpos]) != endpos-startpos {
587                                         atomic.AddInt64(&lowquality, 1)
588                                 }
589                         }()
590                 }
591                 throttle.Wait()
592
593                 log.Infof("%s %s copying path", filelabel, job.label)
594
595                 pathcopy := make([]tileLibRef, len(path))
596                 copy(pathcopy, path)
597                 ret[job.label] = pathcopy
598
599                 basesIn := countBases(job.fasta)
600                 log.Infof("%s %s fasta in %d coverage in %d path len %d low-quality %d skipped-out-of-order %d", filelabel, job.label, len(job.fasta), basesIn, len(path), lowquality, skipped)
601                 stats = append(stats, importStats{
602                         InputFile:              filelabel,
603                         InputLabel:             job.label,
604                         InputLength:            len(job.fasta),
605                         InputCoverage:          basesIn,
606                         PathLength:             len(path),
607                         DroppedOutOfOrderTiles: skipped,
608                 })
609
610                 totalPathLen += len(path)
611         }
612         log.Printf("%s tiled with total path len %d in %d sequences (skipped %d sequences that did not match chromosome regexp, skipped %d out-of-order tags)", filelabel, totalPathLen, len(ret), skippedSequences, totalFoundTags-totalPathLen)
613         return ret, stats, scanner.Err()
614 }
615
616 func (tilelib *tileLibrary) Len() int64 {
617         return atomic.LoadInt64(&tilelib.variants)
618 }
619
620 // Return a tileLibRef for a tile with the given tag and sequence,
621 // adding the sequence to the library if needed.
622 func (tilelib *tileLibrary) getRef(tag tagID, seq []byte) tileLibRef {
623         dropSeq := false
624         if !tilelib.retainNoCalls {
625                 for _, b := range seq {
626                         if b != 'a' && b != 'c' && b != 'g' && b != 't' {
627                                 dropSeq = true
628                                 break
629                         }
630                 }
631         }
632         seqhash := blake2b.Sum256(seq)
633         var vlock sync.Locker
634
635         tilelib.mtx.RLock()
636         if len(tilelib.vlock) > int(tag) {
637                 vlock = tilelib.vlock[tag]
638         }
639         tilelib.mtx.RUnlock()
640
641         if vlock != nil {
642                 vlock.Lock()
643                 for i, varhash := range tilelib.variant[tag] {
644                         if varhash == seqhash {
645                                 vlock.Unlock()
646                                 return tileLibRef{Tag: tag, Variant: tileVariantID(i + 1)}
647                         }
648                 }
649                 vlock.Unlock()
650         } else {
651                 tilelib.mtx.Lock()
652                 if tilelib.variant == nil && tilelib.taglib != nil {
653                         tilelib.variant = make([][][blake2b.Size256]byte, tilelib.taglib.Len())
654                         tilelib.vlock = make([]sync.Locker, tilelib.taglib.Len())
655                         for i := range tilelib.vlock {
656                                 tilelib.vlock[i] = new(sync.Mutex)
657                         }
658                 }
659                 if int(tag) >= len(tilelib.variant) {
660                         oldlen := len(tilelib.vlock)
661                         for i := 0; i < oldlen; i++ {
662                                 tilelib.vlock[i].Lock()
663                         }
664                         // If we haven't seen the tag library yet (as
665                         // in a merge), tilelib.taglib.Len() is
666                         // zero. We can still behave correctly, we
667                         // just need to expand the tilelib.variant and
668                         // tilelib.vlock slices as needed.
669                         if int(tag) >= cap(tilelib.variant) {
670                                 // Allocate 2x capacity.
671                                 newslice := make([][][blake2b.Size256]byte, int(tag)+1, (int(tag)+1)*2)
672                                 copy(newslice, tilelib.variant)
673                                 tilelib.variant = newslice[:int(tag)+1]
674                                 newvlock := make([]sync.Locker, int(tag)+1, (int(tag)+1)*2)
675                                 copy(newvlock, tilelib.vlock)
676                                 tilelib.vlock = newvlock[:int(tag)+1]
677                         } else {
678                                 // Use previously allocated capacity,
679                                 // avoiding copy.
680                                 tilelib.variant = tilelib.variant[:int(tag)+1]
681                                 tilelib.vlock = tilelib.vlock[:int(tag)+1]
682                         }
683                         for i := oldlen; i < len(tilelib.vlock); i++ {
684                                 tilelib.vlock[i] = new(sync.Mutex)
685                         }
686                         for i := 0; i < oldlen; i++ {
687                                 tilelib.vlock[i].Unlock()
688                         }
689                 }
690                 vlock = tilelib.vlock[tag]
691                 tilelib.mtx.Unlock()
692         }
693
694         vlock.Lock()
695         for i, varhash := range tilelib.variant[tag] {
696                 if varhash == seqhash {
697                         vlock.Unlock()
698                         return tileLibRef{Tag: tag, Variant: tileVariantID(i + 1)}
699                 }
700         }
701         atomic.AddInt64(&tilelib.variants, 1)
702         tilelib.variant[tag] = append(tilelib.variant[tag], seqhash)
703         variant := tileVariantID(len(tilelib.variant[tag]))
704         vlock.Unlock()
705
706         if tilelib.retainTileSequences && !dropSeq {
707                 tilelib.mtx.Lock()
708                 if tilelib.seq == nil {
709                         tilelib.seq = map[[blake2b.Size256]byte][]byte{}
710                 }
711                 tilelib.seq[seqhash] = append([]byte(nil), seq...)
712                 tilelib.mtx.Unlock()
713         }
714
715         if tilelib.encoder != nil {
716                 saveSeq := seq
717                 if dropSeq {
718                         // Save the hash, but not the sequence
719                         saveSeq = nil
720                 }
721                 tilelib.encoder.Encode(LibraryEntry{
722                         TileVariants: []TileVariant{{
723                                 Tag:      tag,
724                                 Variant:  variant,
725                                 Blake2b:  seqhash,
726                                 Sequence: saveSeq,
727                         }},
728                 })
729         }
730         return tileLibRef{Tag: tag, Variant: variant}
731 }
732
733 func (tilelib *tileLibrary) TileVariantSequence(libref tileLibRef) []byte {
734         if libref.Variant == 0 || len(tilelib.variant) <= int(libref.Tag) || len(tilelib.variant[libref.Tag]) < int(libref.Variant) {
735                 return nil
736         }
737         return tilelib.seq[tilelib.variant[libref.Tag][libref.Variant-1]]
738 }
739
740 // Tidy deletes unreferenced tile variants and renumbers variants so
741 // more common variants have smaller IDs.
742 func (tilelib *tileLibrary) Tidy() {
743         log.Print("Tidy: compute inref")
744         inref := map[tileLibRef]bool{}
745         for _, refseq := range tilelib.refseqs {
746                 for _, librefs := range refseq {
747                         for _, libref := range librefs {
748                                 inref[libref] = true
749                         }
750                 }
751         }
752         log.Print("Tidy: compute remap")
753         remap := make([][]tileVariantID, len(tilelib.variant))
754         throttle := throttle{Max: runtime.NumCPU() + 1}
755         for tag, oldvariants := range tilelib.variant {
756                 tag, oldvariants := tagID(tag), oldvariants
757                 if tag%1000000 == 0 {
758                         log.Printf("Tidy: tag %d", tag)
759                 }
760                 throttle.Acquire()
761                 go func() {
762                         defer throttle.Release()
763                         uses := make([]int, len(oldvariants))
764                         for _, cg := range tilelib.compactGenomes {
765                                 for phase := 0; phase < 2; phase++ {
766                                         cgi := int(tag)*2 + phase
767                                         if cgi < len(cg) && cg[cgi] > 0 {
768                                                 uses[cg[cgi]-1]++
769                                         }
770                                 }
771                         }
772
773                         // Compute desired order of variants:
774                         // neworder[x] == index in oldvariants that
775                         // should move to position x.
776                         neworder := make([]int, len(oldvariants))
777                         for i := range neworder {
778                                 neworder[i] = i
779                         }
780                         sort.Slice(neworder, func(i, j int) bool {
781                                 if cmp := uses[neworder[i]] - uses[neworder[j]]; cmp != 0 {
782                                         return cmp > 0
783                                 } else {
784                                         return bytes.Compare(oldvariants[neworder[i]][:], oldvariants[neworder[j]][:]) < 0
785                                 }
786                         })
787
788                         // Replace tilelib.variant[tag] with a new
789                         // re-ordered slice of hashes, and make a
790                         // mapping from old to new variant IDs.
791                         remaptag := make([]tileVariantID, len(oldvariants)+1)
792                         newvariants := make([][blake2b.Size256]byte, 0, len(neworder))
793                         for _, oldi := range neworder {
794                                 if uses[oldi] > 0 || inref[tileLibRef{Tag: tag, Variant: tileVariantID(oldi + 1)}] {
795                                         newvariants = append(newvariants, oldvariants[oldi])
796                                         remaptag[oldi+1] = tileVariantID(len(newvariants))
797                                 }
798                         }
799                         tilelib.variant[tag] = newvariants
800                         remap[tag] = remaptag
801                 }()
802         }
803         throttle.Wait()
804
805         // Apply remap to genomes and reference sequences, so they
806         // refer to the same tile variants using the changed IDs.
807         log.Print("Tidy: apply remap")
808         var wg sync.WaitGroup
809         for _, cg := range tilelib.compactGenomes {
810                 cg := cg
811                 wg.Add(1)
812                 go func() {
813                         defer wg.Done()
814                         for idx, variant := range cg {
815                                 cg[idx] = remap[tagID(idx/2)][variant]
816                         }
817                 }()
818         }
819         for _, refcs := range tilelib.refseqs {
820                 for _, refseq := range refcs {
821                         refseq := refseq
822                         wg.Add(1)
823                         go func() {
824                                 defer wg.Done()
825                                 for i, tv := range refseq {
826                                         refseq[i].Variant = remap[tv.Tag][tv.Variant]
827                                 }
828                         }()
829                 }
830         }
831         wg.Wait()
832         log.Print("Tidy: done")
833 }
834
835 func countBases(seq []byte) int {
836         n := 0
837         for _, c := range seq {
838                 if isbase[c] {
839                         n++
840                 }
841         }
842         return n
843 }