fork of https://github.com/sourcegraph/zoekt
1// Copyright 2016 Google Inc. All rights reserved.
2//
3// Licensed under the Apache License, Version 2.0 (the "License");
4// you may not use this file except in compliance with the License.
5// You may obtain a copy of the License at
6//
7// http://www.apache.org/licenses/LICENSE-2.0
8//
9// Unless required by applicable law or agreed to in writing, software
10// distributed under the License is distributed on an "AS IS" BASIS,
11// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12// See the License for the specific language governing permissions and
13// limitations under the License.
14
15package zoekt
16
17import (
18 "bytes"
19 "fmt"
20 "log"
21 "path"
22 "slices"
23 "sort"
24 "strings"
25 "unicode"
26 "unicode/utf8"
27
28 "github.com/sourcegraph/zoekt/ctags"
29)
30
31var _ = log.Println
32
33// contentProvider is an abstraction to treat matches for names and
34// content with the same code.
35type contentProvider struct {
36 id *indexData
37 stats *Stats
38
39 // mutable
40 err error
41 idx uint32
42 _data []byte
43 _nl []uint32
44 _nlBuf []uint32
45 _sects []DocumentSection
46 _sectBuf []DocumentSection
47 fileSize uint32
48}
49
50// setDocument skips to the given document.
51func (p *contentProvider) setDocument(docID uint32) {
52 fileStart := p.id.boundaries[docID]
53
54 p.idx = docID
55 p.fileSize = p.id.boundaries[docID+1] - fileStart
56
57 p._nl = nil
58 p._sects = nil
59 p._data = nil
60}
61
62func (p *contentProvider) docSections() []DocumentSection {
63 if p._sects == nil {
64 var sz uint32
65 p._sects, sz, p.err = p.id.readDocSections(p.idx, p._sectBuf)
66 p.stats.ContentBytesLoaded += int64(sz)
67 p._sectBuf = p._sects
68 }
69 return p._sects
70}
71
72func (p *contentProvider) newlines() newlines {
73 if p._nl == nil {
74 var sz uint32
75 p._nl, sz, p.err = p.id.readNewlines(p.idx, p._nlBuf)
76 p._nlBuf = p._nl
77 p.stats.ContentBytesLoaded += int64(sz)
78 }
79 return newlines{locs: p._nl, fileSize: p.fileSize}
80}
81
82func (p *contentProvider) data(fileName bool) []byte {
83 if fileName {
84 return p.id.fileNameContent[p.id.fileNameIndex[p.idx]:p.id.fileNameIndex[p.idx+1]]
85 }
86
87 if p._data == nil {
88 p._data, p.err = p.id.readContents(p.idx)
89 p.stats.FilesLoaded++
90 p.stats.ContentBytesLoaded += int64(len(p._data))
91 }
92 return p._data
93}
94
95// Find offset in bytes (relative to corpus start) for an offset in
96// runes (relative to document start). If filename is set, the corpus
97// is the set of filenames, with the document being the name itself.
98func (p *contentProvider) findOffset(filename bool, r uint32) uint32 {
99 if p.id.metaData.PlainASCII {
100 return r
101 }
102
103 sample := p.id.runeOffsets
104 runeEnds := p.id.fileEndRunes
105 fileStartByte := p.id.boundaries[p.idx]
106 if filename {
107 sample = p.id.fileNameRuneOffsets
108 runeEnds = p.id.fileNameEndRunes
109 fileStartByte = p.id.fileNameIndex[p.idx]
110 }
111
112 absR := r
113 if p.idx > 0 {
114 absR += runeEnds[p.idx-1]
115 }
116
117 byteOff, left := sample.lookup(absR)
118
119 var data []byte
120
121 if filename {
122 data = p.id.fileNameContent[byteOff:]
123 } else {
124 data, p.err = p.id.readContentSlice(byteOff, 3*runeOffsetFrequency)
125 if p.err != nil {
126 return 0
127 }
128 }
129 for left > 0 {
130 _, sz := utf8.DecodeRune(data)
131 byteOff += uint32(sz)
132 data = data[sz:]
133 left--
134 }
135
136 byteOff -= fileStartByte
137 return byteOff
138}
139
140// fillMatches converts the internal candidateMatch slice into our API's LineMatch.
141// It only ever returns content XOR filename matches, not both. If there are any
142// content matches, these are always returned, and we omit filename matches.
143//
144// Performance invariant: ms is sorted and non-overlapping.
145//
146// Note: the byte slices may be backed by mmapped data, so before being
147// returned by the API it needs to be copied.
148func (p *contentProvider) fillMatches(ms []*candidateMatch, numContextLines int, language string, debug bool) []LineMatch {
149 var filenameMatches []*candidateMatch
150 contentMatches := make([]*candidateMatch, 0, len(ms))
151
152 for _, m := range ms {
153 if m.fileName {
154 filenameMatches = append(filenameMatches, m)
155 } else {
156 contentMatches = append(contentMatches, m)
157 }
158 }
159
160 // If there are any content matches, we only return these and skip filename matches.
161 if len(contentMatches) > 0 {
162 contentMatches = breakMatchesOnNewlines(contentMatches, p.data(false))
163 return p.fillContentMatches(contentMatches, numContextLines, language, debug)
164 }
165
166 // Otherwise, we return a single line containing the filematch match.
167 score, debugScore, _ := p.candidateMatchScore(filenameMatches, language, debug)
168 res := LineMatch{
169 Line: p.id.fileName(p.idx),
170 FileName: true,
171 Score: score,
172 DebugScore: debugScore,
173 }
174
175 for _, m := range ms {
176 res.LineFragments = append(res.LineFragments, LineFragmentMatch{
177 LineOffset: int(m.byteOffset),
178 MatchLength: int(m.byteMatchSz),
179 Offset: m.byteOffset,
180 })
181 }
182
183 return []LineMatch{res}
184
185}
186
187// fillChunkMatches converts the internal candidateMatch slice into our API's ChunkMatch.
188// It only ever returns content XOR filename matches, not both. If there are any content
189// matches, these are always returned, and we omit filename matches.
190//
191// Performance invariant: ms is sorted and non-overlapping.
192//
193// Note: the byte slices may be backed by mmapped data, so before being
194// returned by the API it needs to be copied.
195func (p *contentProvider) fillChunkMatches(ms []*candidateMatch, numContextLines int, language string, debug bool) []ChunkMatch {
196 var filenameMatches []*candidateMatch
197 contentMatches := make([]*candidateMatch, 0, len(ms))
198
199 for _, m := range ms {
200 if m.fileName {
201 filenameMatches = append(filenameMatches, m)
202 } else {
203 contentMatches = append(contentMatches, m)
204 }
205 }
206
207 // If there are any content matches, we only return these and skip filename matches.
208 if len(contentMatches) > 0 {
209 return p.fillContentChunkMatches(contentMatches, numContextLines, language, debug)
210 }
211
212 // Otherwise, we return a single chunk representing the filename match.
213 score, debugScore, _ := p.candidateMatchScore(filenameMatches, language, debug)
214 fileName := p.id.fileName(p.idx)
215 ranges := make([]Range, 0, len(ms))
216 for _, m := range ms {
217 ranges = append(ranges, Range{
218 Start: Location{
219 ByteOffset: m.byteOffset,
220 LineNumber: 1,
221 Column: uint32(utf8.RuneCount(fileName[:m.byteOffset]) + 1),
222 },
223 End: Location{
224 ByteOffset: m.byteOffset + m.byteMatchSz,
225 LineNumber: 1,
226 Column: uint32(utf8.RuneCount(fileName[:m.byteOffset+m.byteMatchSz]) + 1),
227 },
228 })
229 }
230
231 return []ChunkMatch{{
232 Content: fileName,
233 ContentStart: Location{ByteOffset: 0, LineNumber: 1, Column: 1},
234 Ranges: ranges,
235 FileName: true,
236
237 Score: score,
238 DebugScore: debugScore,
239 }}
240}
241
242func (p *contentProvider) fillContentMatches(ms []*candidateMatch, numContextLines int, language string, debug bool) []LineMatch {
243 var result []LineMatch
244 for len(ms) > 0 {
245 m := ms[0]
246 num := p.newlines().atOffset(m.byteOffset)
247 lineStart := int(p.newlines().lineStart(num))
248 nextLineStart := int(p.newlines().lineStart(num + 1))
249
250 var lineCands []*candidateMatch
251
252 endMatch := m.byteOffset + m.byteMatchSz
253
254 for len(ms) > 0 {
255 m := ms[0]
256 if int(m.byteOffset) < nextLineStart {
257 endMatch = m.byteOffset + m.byteMatchSz
258 lineCands = append(lineCands, m)
259 ms = ms[1:]
260 } else {
261 break
262 }
263 }
264
265 if len(lineCands) == 0 {
266 log.Panicf(
267 "%s %v infinite loop: num %d start,end %d,%d, offset %d",
268 p.id.fileName(p.idx), p.id.metaData,
269 num, lineStart, nextLineStart,
270 m.byteOffset)
271 }
272
273 data := p.data(false)
274
275 // Due to merging matches, we may have a match that
276 // crosses a line boundary. Prevent confusion by
277 // taking lines until we pass the last match
278 for nextLineStart < len(data) && endMatch > uint32(nextLineStart) {
279 next := bytes.IndexByte(data[nextLineStart:], '\n')
280 if next == -1 {
281 nextLineStart = len(data)
282 } else {
283 // TODO(hanwen): test that checks "+1" part here.
284 nextLineStart += next + 1
285 }
286 }
287
288 finalMatch := LineMatch{
289 LineStart: lineStart,
290 LineEnd: nextLineStart,
291 LineNumber: num,
292 }
293 finalMatch.Line = data[lineStart:nextLineStart]
294
295 if numContextLines > 0 {
296 finalMatch.Before = p.newlines().getLines(data, num-numContextLines, num)
297 finalMatch.After = p.newlines().getLines(data, num+1, num+1+numContextLines)
298 }
299
300 score, debugScore, symbolInfo := p.candidateMatchScore(lineCands, language, debug)
301 finalMatch.Score = score
302 finalMatch.DebugScore = debugScore
303
304 for i, m := range lineCands {
305 fragment := LineFragmentMatch{
306 Offset: m.byteOffset,
307 LineOffset: int(m.byteOffset) - lineStart,
308 MatchLength: int(m.byteMatchSz),
309 }
310 if i < len(symbolInfo) && symbolInfo[i] != nil {
311 fragment.SymbolInfo = symbolInfo[i]
312 }
313
314 finalMatch.LineFragments = append(finalMatch.LineFragments, fragment)
315 }
316 result = append(result, finalMatch)
317 }
318 return result
319}
320
321func (p *contentProvider) fillContentChunkMatches(ms []*candidateMatch, numContextLines int, language string, debug bool) []ChunkMatch {
322 newlines := p.newlines()
323 data := p.data(false)
324
325 // columnHelper prevents O(len(ms) * len(data)) lookups for all columns.
326 // However, it depends on ms being sorted by byteOffset and non-overlapping.
327 // This invariant is true at the time of writing, but we conservatively
328 // enforce this. Note: chunkCandidates preserves the sorting so safe to
329 // transform now.
330 columnHelper := columnHelper{data: data}
331 if !sort.IsSorted((sortByOffsetSlice)(ms)) {
332 log.Printf("WARN: performance invariant violated. candidate matches are not sorted in fillContentChunkMatches. Report to developers.")
333 sort.Sort((sortByOffsetSlice)(ms))
334 }
335
336 chunks := chunkCandidates(ms, newlines, numContextLines)
337 chunkMatches := make([]ChunkMatch, 0, len(chunks))
338 for _, chunk := range chunks {
339 score, debugScore, symbolInfo := p.candidateMatchScore(chunk.candidates, language, debug)
340
341 ranges := make([]Range, 0, len(chunk.candidates))
342 for _, cm := range chunk.candidates {
343 startOffset := cm.byteOffset
344 endOffset := cm.byteOffset + cm.byteMatchSz
345 startLine, endLine := newlines.offsetRangeToLineRange(startOffset, endOffset)
346
347 ranges = append(ranges, Range{
348 Start: Location{
349 ByteOffset: startOffset,
350 LineNumber: uint32(startLine),
351 Column: columnHelper.get(int(newlines.lineStart(startLine)), startOffset),
352 },
353 End: Location{
354 ByteOffset: endOffset,
355 LineNumber: uint32(endLine),
356 Column: columnHelper.get(int(newlines.lineStart(endLine)), endOffset),
357 },
358 })
359 }
360
361 firstLineNumber := int(chunk.firstLine) - numContextLines
362 if firstLineNumber < 1 {
363 firstLineNumber = 1
364 }
365 firstLineStart := newlines.lineStart(firstLineNumber)
366
367 chunkMatches = append(chunkMatches, ChunkMatch{
368 Content: newlines.getLines(data, firstLineNumber, int(chunk.lastLine)+numContextLines+1),
369 ContentStart: Location{
370 ByteOffset: firstLineStart,
371 LineNumber: uint32(firstLineNumber),
372 Column: 1,
373 },
374 FileName: false,
375 Ranges: ranges,
376 SymbolInfo: symbolInfo,
377 Score: score,
378 DebugScore: debugScore,
379 })
380 }
381 return chunkMatches
382}
383
384type candidateChunk struct {
385 candidates []*candidateMatch
386 firstLine uint32 // 1-based, inclusive
387 lastLine uint32 // 1-based, inclusive
388 minOffset uint32 // 0-based, inclusive
389 maxOffset uint32 // 0-based, exclusive
390}
391
392// chunkCandidates groups a set of sorted, non-overlapping candidate matches by line number. Adjacent
393// chunks will be merged if adding `numContextLines` to the beginning and end of the chunk would cause
394// it to overlap with an adjacent chunk.
395//
396// input invariants: ms is sorted by byteOffset and is non overlapping with respect to endOffset.
397// output invariants: if you flatten candidates the input invariant is retained.
398func chunkCandidates(ms []*candidateMatch, newlines newlines, numContextLines int) []candidateChunk {
399 var chunks []candidateChunk
400 for _, m := range ms {
401 startOffset := m.byteOffset
402 endOffset := m.byteOffset + m.byteMatchSz
403 firstLine, lastLine := newlines.offsetRangeToLineRange(startOffset, endOffset)
404
405 if len(chunks) > 0 && int(chunks[len(chunks)-1].lastLine)+numContextLines >= firstLine-numContextLines {
406 // If a new chunk created with the current candidateMatch would
407 // overlap with the previous chunk, instead add the candidateMatch
408 // to the last chunk and extend end of the last chunk.
409 last := &chunks[len(chunks)-1]
410 last.candidates = append(last.candidates, m)
411 if last.maxOffset < endOffset {
412 last.lastLine = uint32(lastLine)
413 last.maxOffset = uint32(endOffset)
414 }
415 } else {
416 chunks = append(chunks, candidateChunk{
417 firstLine: uint32(firstLine),
418 lastLine: uint32(lastLine),
419 minOffset: startOffset,
420 maxOffset: endOffset,
421 candidates: []*candidateMatch{m},
422 })
423 }
424 }
425 return chunks
426}
427
428// columnHelper is a helper struct which caches the number of runes last
429// counted. If we naively use utf8.RuneCount for each match on a line, this
430// leads to an O(nm) algorithm where m is the number of matches and n is the
431// length of the line. Aassuming we our candidates are increasing in offset
432// makes this operation O(n) instead.
433type columnHelper struct {
434 data []byte
435
436 // 0 values for all these are valid values
437 lastLineOffset int
438 lastOffset uint32
439 lastRuneCount uint32
440}
441
442// get returns the line column for offset. offset is the byte offset of the
443// rune in data. lineOffset is the byte offset inside of data for the line
444// containing offset.
445func (c *columnHelper) get(lineOffset int, offset uint32) uint32 {
446 var runeCount uint32
447
448 if lineOffset == c.lastLineOffset && offset >= c.lastOffset {
449 // Can count from last calculation
450 runeCount = c.lastRuneCount + uint32(utf8.RuneCount(c.data[c.lastOffset:offset]))
451 } else {
452 // Need to count from the beginning of line
453 runeCount = uint32(utf8.RuneCount(c.data[lineOffset:offset]))
454 }
455
456 c.lastLineOffset = lineOffset
457 c.lastOffset = offset
458 c.lastRuneCount = runeCount
459
460 return runeCount + 1
461}
462
463type newlines struct {
464 // locs is the sorted set of byte offsets of the newlines in the file
465 locs []uint32
466
467 // fileSize is just the number of bytes in the file. It is stored
468 // on this struct so we can safely know the length of the last line
469 // in the file since not all files end in a newline.
470 fileSize uint32
471}
472
473// atOffset returns the line containing the offset. If the offset lands on
474// the newline ending line M, we return M.
475func (nls newlines) atOffset(offset uint32) (lineNumber int) {
476 idx := sort.Search(len(nls.locs), func(n int) bool {
477 return nls.locs[n] >= offset
478 })
479 return idx + 1
480}
481
482// lineStart returns the byte offset of the beginning of the given line.
483// lineNumber is 1-based. If lineNumber is out of range of the lines in the
484// file, the return value will be clamped to [0,fileSize].
485func (nls newlines) lineStart(lineNumber int) uint32 {
486 // nls.locs[0] + 1 is the start of the 2nd line of data.
487 startIdx := lineNumber - 2
488
489 if startIdx < 0 {
490 return 0
491 } else if startIdx >= len(nls.locs) {
492 return nls.fileSize
493 } else {
494 return nls.locs[startIdx] + 1
495 }
496}
497
498// offsetRangeToLineRange returns range of lines that fully contains the given byte range.
499// The inputs are 0-based byte offsets into the file representing the (exclusive) range [startOffset, endOffset).
500// The return values are 1-based line numbers representing the (inclusive) range [startLine, endLine].
501func (nls newlines) offsetRangeToLineRange(startOffset, endOffset uint32) (startLine, endLine int) {
502 startLine = nls.atOffset(startOffset)
503 endLine = nls.atOffset(
504 max(startOffset, max(endOffset, 1)-1), // clamp endOffset and prevent underflow
505 )
506 return startLine, endLine
507}
508
509// getLines returns a slice of data containing the lines [low, high).
510// low is 1-based and inclusive. high is 1-based and exclusive.
511func (nls newlines) getLines(data []byte, low, high int) []byte {
512 if low >= high {
513 return nil
514 }
515
516 return data[nls.lineStart(low):nls.lineStart(high)]
517}
518
519const (
520 // Query-dependent scoring signals. All of these together are bounded at ~9000
521 // (scoreWordMatch + scoreSymbol + scoreKindMatch * 10 + scoreFactorAtomMatch).
522 scorePartialWordMatch = 50.0
523 scoreWordMatch = 500.0
524 scoreBase = 7000.0
525 scorePartialBase = 4000.0
526 scoreSymbol = 7000.0
527 scorePartialSymbol = 4000.0
528 scoreKindMatch = 100.0
529 scoreFactorAtomMatch = 400.0
530
531 // File-only scoring signals. For now these are also bounded ~9000 to give them
532 // equal weight with the query-dependent signals.
533 scoreFileRankFactor = 9000.0
534 scoreFileOrderFactor = 10.0
535 scoreRepoRankFactor = 20.0
536
537 // Used for ordering line and chunk matches within a file.
538 scoreLineOrderFactor = 1.0
539)
540
541// findMaxOverlappingSection returns the index of the section in secs that
542// overlaps the most with the area defined by off and sz, relative to the size
543// of the section. If no section overlaps, it returns 0, false. If multiple
544// sections overlap the same amount, the first one is returned.
545//
546// The implementation assumes that sections do not overlap and are sorted by
547// DocumentSection.Start.
548func findMaxOverlappingSection(secs []DocumentSection, off, sz uint32) (uint32, bool) {
549 start := off
550 end := off + sz
551
552 // Find the first section that might overlap
553 j := sort.Search(len(secs), func(i int) bool { return secs[i].End > start })
554
555 if j == len(secs) || secs[j].Start >= end {
556 // No overlap.
557 return 0, false
558 }
559
560 relOverlap := func(j int) float64 {
561 secSize := secs[j].End - secs[j].Start
562 if secSize == 0 {
563 return 0
564 }
565 // This cannot overflow because we make sure there is overlap before calling relOverlap
566 overlap := min(secs[j].End, end) - max(secs[j].Start, start)
567 return float64(overlap) / float64(secSize)
568 }
569
570 ol1 := relOverlap(j)
571 if epsilonEqualsOne(ol1) || j == len(secs)-1 || secs[j+1].Start >= end {
572 return uint32(j), ol1 > 0
573 }
574
575 // We know that [off,off+sz[ overlaps with at least 2 sections. We only have to check
576 // if the second section overlaps more than the first one, because a third
577 // section can only overlap if the overlap with the second section is complete.
578 ol2 := relOverlap(j + 1)
579 if ol2 > ol1 {
580 return uint32(j + 1), ol2 > 0
581 }
582
583 return uint32(j), ol1 > 0
584}
585
586func (p *contentProvider) findSymbol(cm *candidateMatch) (DocumentSection, *Symbol, bool) {
587 if cm.fileName {
588 return DocumentSection{}, nil, false
589 }
590
591 secs := p.docSections()
592
593 secIdx, ok := cm.symbolIdx, cm.symbol
594 if !ok {
595 // Not from a symbol matchTree. Let's see if it overlaps with a symbol.
596 secIdx, ok = findMaxOverlappingSection(secs, cm.byteOffset, cm.byteMatchSz)
597 }
598 if !ok {
599 return DocumentSection{}, nil, false
600 }
601
602 sec := secs[secIdx]
603
604 // Now lets hydrate in the SymbolInfo. We do not hydrate in SymbolInfo.Sym
605 // since some callsites do not need it stored, and that incurs an extra
606 // copy.
607 //
608 // 2024-01-08 we are refactoring this and the code path indicates this can
609 // fail, so callers need to handle nil symbol. However, it would be
610 // surprising that we have a matching section but not symbol data.
611 start := p.id.fileEndSymbol[p.idx]
612 si := p.id.symbols.data(start + secIdx)
613
614 return sec, si, true
615}
616
617func (p *contentProvider) candidateMatchScore(ms []*candidateMatch, language string, debug bool) (float64, string, []*Symbol) {
618 type debugScore struct {
619 what string
620 score float64
621 }
622
623 score := &debugScore{}
624 maxScore := &debugScore{}
625
626 addScore := func(what string, s float64) {
627 if s != 0 && debug {
628 score.what += fmt.Sprintf("%s:%.2f, ", what, s)
629 }
630 score.score += s
631 }
632
633 filename := p.data(true)
634 var symbolInfo []*Symbol
635
636 for i, m := range ms {
637 data := p.data(m.fileName)
638
639 endOffset := m.byteOffset + m.byteMatchSz
640 startBoundary := m.byteOffset < uint32(len(data)) && (m.byteOffset == 0 || byteClass(data[m.byteOffset-1]) != byteClass(data[m.byteOffset]))
641 endBoundary := endOffset > 0 && (endOffset == uint32(len(data)) || byteClass(data[endOffset-1]) != byteClass(data[endOffset]))
642
643 score.score = 0
644 score.what = ""
645
646 if startBoundary && endBoundary {
647 addScore("WordMatch", scoreWordMatch)
648 } else if startBoundary || endBoundary {
649 addScore("PartialWordMatch", scorePartialWordMatch)
650 }
651
652 if m.fileName {
653 sep := bytes.LastIndexByte(data, '/')
654 startMatch := int(m.byteOffset) == sep+1
655 endMatch := endOffset == uint32(len(data))
656 if startMatch && endMatch {
657 addScore("Base", scoreBase)
658 } else if startMatch || endMatch {
659 addScore("EdgeBase", (scoreBase+scorePartialBase)/2)
660 } else if sep < int(m.byteOffset) {
661 addScore("InnerBase", scorePartialBase)
662 }
663 } else if sec, si, ok := p.findSymbol(m); ok {
664 startMatch := sec.Start == m.byteOffset
665 endMatch := sec.End == endOffset
666 if startMatch && endMatch {
667 addScore("Symbol", scoreSymbol)
668 } else if startMatch || endMatch {
669 addScore("EdgeSymbol", (scoreSymbol+scorePartialSymbol)/2)
670 } else {
671 addScore("OverlapSymbol", scorePartialSymbol)
672 }
673
674 // Score based on symbol data
675 if si != nil {
676 symbolKind := ctags.ParseSymbolKind(si.Kind)
677 sym := sectionSlice(data, sec)
678
679 addScore(fmt.Sprintf("kind:%s:%s", language, si.Kind), scoreSymbolKind(language, filename, sym, symbolKind))
680
681 // This is from a symbol tree, so we need to store the symbol
682 // information.
683 if m.symbol {
684 if symbolInfo == nil {
685 symbolInfo = make([]*Symbol, len(ms))
686 }
687 // findSymbols does not hydrate in Sym. So we need to store it.
688 si.Sym = string(sym)
689 symbolInfo[i] = si
690 }
691 }
692 }
693
694 // scoreWeight != 1 means it affects score
695 if !epsilonEqualsOne(m.scoreWeight) {
696 score.score = score.score * m.scoreWeight
697 if debug {
698 score.what += fmt.Sprintf("boost:%.2f, ", m.scoreWeight)
699 }
700 }
701
702 if score.score > maxScore.score {
703 maxScore.score = score.score
704 maxScore.what = score.what
705 }
706 }
707
708 if debug {
709 maxScore.what = fmt.Sprintf("score:%.2f <- %s", maxScore.score, strings.TrimSuffix(maxScore.what, ", "))
710 }
711
712 return maxScore.score, maxScore.what, symbolInfo
713}
714
715// sectionSlice will return data[sec.Start:sec.End] but will clip Start and
716// End such that it won't be out of range.
717func sectionSlice(data []byte, sec DocumentSection) []byte {
718 l := uint32(len(data))
719 if sec.Start >= l {
720 return nil
721 }
722 if sec.End > l {
723 sec.End = l
724 }
725 return data[sec.Start:sec.End]
726}
727
728// scoreSymbolKind boosts a match based on the combination of language, symbol
729// and kind. The language string comes from go-enry, the symbol and kind from
730// ctags.
731func scoreSymbolKind(language string, filename []byte, sym []byte, kind ctags.SymbolKind) float64 {
732 var factor float64
733
734 // Generic ranking which will be overriden by language specific ranking
735 switch kind {
736 case ctags.Type: // scip-ctags regression workaround https://github.com/sourcegraph/sourcegraph/issues/57659
737 factor = 8
738 case ctags.Class:
739 factor = 10
740 case ctags.Struct:
741 factor = 9.5
742 case ctags.Enum:
743 factor = 9
744 case ctags.Interface:
745 factor = 8
746 case ctags.Function, ctags.Method:
747 factor = 7
748 case ctags.Field:
749 factor = 5.5
750 case ctags.Constant:
751 factor = 5
752 case ctags.Variable:
753 factor = 4
754 default:
755 // For all other kinds, assign a low score by default.
756 factor = 1
757 }
758
759 switch language {
760 case "Java", "java":
761 switch kind {
762 // 2022-03-30: go-ctags contains a regex rule for Java classes that sets "kind"
763 // to "classes" instead of "c". We have to cover both cases to support existing
764 // indexes.
765 case ctags.Class:
766 factor = 10
767 case ctags.Enum:
768 factor = 9
769 case ctags.Interface:
770 factor = 8
771 case ctags.Method:
772 factor = 7
773 case ctags.Field:
774 factor = 6
775 case ctags.EnumConstant:
776 factor = 5
777 }
778 case "Kotlin", "kotlin":
779 switch kind {
780 case ctags.Class:
781 factor = 10
782 case ctags.Interface:
783 factor = 9
784 case ctags.Method:
785 factor = 8
786 case ctags.TypeAlias:
787 factor = 7
788 case ctags.Constant:
789 factor = 6
790 case ctags.Variable:
791 factor = 5
792 }
793 case "Go", "go":
794 switch kind {
795 // scip-ctags regression workaround https://github.com/sourcegraph/sourcegraph/issues/57659
796 // for each case a description of the fields in ctags in the comment
797 case ctags.Type: // interface struct talias
798 factor = 9
799 case ctags.Interface: // interfaces
800 factor = 10
801 case ctags.Struct: // structs
802 factor = 9
803 case ctags.TypeAlias: // type aliases
804 factor = 9
805 case ctags.MethodSpec: // interface method specification
806 factor = 8.5
807 case ctags.Method, ctags.Function: // functions
808 factor = 8
809 case ctags.Field: // struct fields
810 factor = 7
811 case ctags.Constant: // constants
812 factor = 6
813 case ctags.Variable: // variables
814 factor = 5
815 }
816
817 // Boost exported go symbols. Same implementation as token.IsExported
818 if ch, _ := utf8.DecodeRune(sym); unicode.IsUpper(ch) {
819 factor += 0.5
820 }
821
822 if bytes.HasSuffix(filename, []byte("_test.go")) {
823 factor *= 0.8
824 }
825
826 // Could also rank on:
827 //
828 // - anonMember struct anonymous members
829 // - packageName name for specifying imported package
830 // - receiver receivers
831 // - package packages
832 // - type types
833 // - unknown unknown
834 case "C++", "c++":
835 switch kind {
836 case ctags.Class: // classes
837 factor = 10
838 case ctags.Enum: // enumeration names
839 factor = 9
840 case ctags.Function: // function definitions
841 factor = 8
842 case ctags.Struct: // structure names
843 factor = 7
844 case ctags.Union: // union names
845 factor = 6
846 case ctags.TypeAlias: // typedefs
847 factor = 5
848 case ctags.Field: // class, struct, and union members
849 factor = 4
850 case ctags.Variable: // varialbe definitions
851 factor = 3
852 }
853 // Could also rank on:
854 // NAME DESCRIPTION
855 // macro macro definitions
856 // enumerator enumerators (values inside an enumeration)
857 // header included header files
858 // namespace namespaces
859 // variable variable definitions
860 case "Scala", "scala":
861 switch kind {
862 case ctags.Class:
863 factor = 10
864 case ctags.Interface:
865 factor = 9
866 case ctags.Object:
867 factor = 8
868 case ctags.Function:
869 factor = 7
870 case ctags.Type:
871 factor = 6
872 case ctags.Variable:
873 factor = 5
874 case ctags.Package:
875 factor = 4
876 }
877 case "Python", "python":
878 switch kind {
879 case ctags.Class: // classes
880 factor = 10
881 case ctags.Function, ctags.Method: // function definitions
882 factor = 8
883 case ctags.Field: // class, struct, and union members
884 factor = 4
885 case ctags.Variable: // variable definitions
886 factor = 3
887 case ctags.Local: // local variables
888 factor = 2
889 }
890 // Could also rank on:
891 //
892 // - namespace name referring a module defined in other file
893 // - module modules
894 // - unknown name referring a class/variable/function/module defined in other module
895 // - parameter function parameters
896 case "Ruby", "ruby":
897 switch kind {
898 case ctags.Class:
899 factor = 10
900 case ctags.Method:
901 factor = 9
902 case ctags.MethodAlias:
903 factor = 8
904 case ctags.Module:
905 factor = 7
906 case ctags.SingletonMethod:
907 factor = 6
908 case ctags.Constant:
909 factor = 5
910 case ctags.Accessor:
911 factor = 4
912 case ctags.Library:
913 factor = 3
914 }
915 case "PHP", "php":
916 switch kind {
917 case ctags.Class:
918 factor = 10
919 case ctags.Interface:
920 factor = 9
921 case ctags.Function:
922 factor = 8
923 case ctags.Trait:
924 factor = 7
925 case ctags.Define:
926 factor = 6
927 case ctags.Namespace:
928 factor = 5
929 case ctags.MethodAlias:
930 factor = 4
931 case ctags.Variable:
932 factor = 3
933 case ctags.Local:
934 factor = 3
935 }
936 case "GraphQL", "graphql":
937 switch kind {
938 case ctags.Type:
939 factor = 10
940 }
941 case "Markdown", "markdown":
942 // Headers are good signal in docs, but do not rank as highly as code.
943 switch kind {
944 case ctags.Chapter: // #
945 factor = 4
946 case ctags.Section: // ##
947 factor = 3
948 case ctags.Subsection: // ###
949 factor = 2
950 }
951 }
952
953 return factor * scoreKindMatch
954}
955
956type matchScoreSlice []LineMatch
957
958func (m matchScoreSlice) Len() int { return len(m) }
959func (m matchScoreSlice) Swap(i, j int) { m[i], m[j] = m[j], m[i] }
960func (m matchScoreSlice) Less(i, j int) bool { return m[i].Score > m[j].Score }
961
962type chunkMatchScoreSlice []ChunkMatch
963
964func (m chunkMatchScoreSlice) Len() int { return len(m) }
965func (m chunkMatchScoreSlice) Swap(i, j int) { m[i], m[j] = m[j], m[i] }
966func (m chunkMatchScoreSlice) Less(i, j int) bool { return m[i].Score > m[j].Score }
967
968type fileMatchesByScore []FileMatch
969
970func (m fileMatchesByScore) Len() int { return len(m) }
971func (m fileMatchesByScore) Swap(i, j int) { m[i], m[j] = m[j], m[i] }
972func (m fileMatchesByScore) Less(i, j int) bool { return m[i].Score > m[j].Score }
973
974func sortMatchesByScore(ms []LineMatch) {
975 sort.Sort(matchScoreSlice(ms))
976}
977
978func sortChunkMatchesByScore(ms []ChunkMatch) {
979 sort.Sort(chunkMatchScoreSlice(ms))
980}
981
982// SortFiles sorts files matches in the order we want to present results to
983// users. The order depends on the match score, which includes both
984// query-dependent signals like word overlap, and file-only signals like the
985// file ranks (if file ranks are enabled).
986//
987// We don't only use the scores, we will also boost some results to present
988// files with novel extensions.
989func SortFiles(ms []FileMatch) {
990 sort.Sort(fileMatchesByScore(ms))
991
992 // Boost a file extension not in the top 3 to the third filematch.
993 boostNovelExtension(ms, 2, 0.9)
994}
995
996func boostNovelExtension(ms []FileMatch, boostOffset int, minScoreRatio float64) {
997 if len(ms) <= boostOffset+1 {
998 return
999 }
1000
1001 top := ms[:boostOffset]
1002 candidates := ms[boostOffset:]
1003
1004 // Don't bother boosting something which is significantly different to the
1005 // result it replaces.
1006 minScoreForNovelty := candidates[0].Score * minScoreRatio
1007
1008 // We want to look for an ext that isn't in the top exts
1009 exts := make([]string, len(top))
1010 for i := range top {
1011 exts[i] = path.Ext(top[i].FileName)
1012 }
1013
1014 for i := range candidates {
1015 // Do not assume sorted due to boostNovelExtension being called on subsets
1016 if candidates[i].Score < minScoreForNovelty {
1017 continue
1018 }
1019
1020 if slices.Contains(exts, path.Ext(candidates[i].FileName)) {
1021 continue
1022 }
1023
1024 // Found what we are looking for, now boost to front of candidates (which
1025 // is ms[boostOffset])
1026 for ; i > 0; i-- {
1027 candidates[i], candidates[i-1] = candidates[i-1], candidates[i]
1028 }
1029 return
1030 }
1031}