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