forked from system-pclub/GCatch
/
workspace_symbol.go
581 lines (528 loc) · 16.1 KB
/
workspace_symbol.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
// Copyright 2020 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package source
import (
"context"
"fmt"
"go/types"
"path/filepath"
"runtime"
"sort"
"strings"
"unicode"
"github.com/system-pclub/GCatch/GCatch/tools/internal/event"
"github.com/system-pclub/GCatch/GCatch/tools/internal/lsp/fuzzy"
"github.com/system-pclub/GCatch/GCatch/tools/internal/lsp/protocol"
"github.com/system-pclub/GCatch/GCatch/tools/internal/span"
)
// Symbol holds a precomputed symbol value. Note: we avoid using the
// protocol.SymbolInformation struct here in order to reduce the size of each
// symbol.
type Symbol struct {
Name string
Kind protocol.SymbolKind
Range protocol.Range
}
// maxSymbols defines the maximum number of symbol results that should ever be
// sent in response to a client.
const maxSymbols = 100
// WorkspaceSymbols matches symbols across all views using the given query,
// according to the match semantics parameterized by matcherType and style.
//
// The workspace symbol method is defined in the spec as follows:
//
// The workspace symbol request is sent from the client to the server to
// list project-wide symbols matching the query string.
//
// It is unclear what "project-wide" means here, but given the parameters of
// workspace/symbol do not include any workspace identifier, then it has to be
// assumed that "project-wide" means "across all workspaces". Hence why
// WorkspaceSymbols receives the views []View.
//
// However, it then becomes unclear what it would mean to call WorkspaceSymbols
// with a different configured SymbolMatcher per View. Therefore we assume that
// Session level configuration will define the SymbolMatcher to be used for the
// WorkspaceSymbols method.
func WorkspaceSymbols(ctx context.Context, matcherType SymbolMatcher, style SymbolStyle, views []View, query string) ([]protocol.SymbolInformation, error) {
ctx, done := event.Start(ctx, "source.WorkspaceSymbols")
defer done()
if query == "" {
return nil, nil
}
sc := newSymbolCollector(matcherType, style, query)
return sc.walk(ctx, views)
}
// A matcherFunc returns the index and score of a symbol match.
//
// See the comment for symbolCollector for more information.
type matcherFunc func(chunks []string) (int, float64)
// A symbolizer returns the best symbol match for a name with pkg, according to
// some heuristic. The symbol name is passed as the slice nameParts of logical
// name pieces. For example, for myType.field the caller can pass either
// []string{"myType.field"} or []string{"myType.", "field"}.
//
// See the comment for symbolCollector for more information.
type symbolizer func(name string, pkg Metadata, m matcherFunc) ([]string, float64)
func fullyQualifiedSymbolMatch(name string, pkg Metadata, matcher matcherFunc) ([]string, float64) {
_, score := dynamicSymbolMatch(name, pkg, matcher)
if score > 0 {
return []string{pkg.PackagePath(), ".", name}, score
}
return nil, 0
}
func dynamicSymbolMatch(name string, pkg Metadata, matcher matcherFunc) ([]string, float64) {
var score float64
endsInPkgName := strings.HasSuffix(pkg.PackagePath(), pkg.PackageName())
// If the package path does not end in the package name, we need to check the
// package-qualified symbol as an extra pass first.
if !endsInPkgName {
pkgQualified := []string{pkg.PackageName(), ".", name}
idx, score := matcher(pkgQualified)
nameStart := len(pkg.PackageName()) + 1
if score > 0 {
// If our match is contained entirely within the unqualified portion,
// just return that.
if idx >= nameStart {
return []string{name}, score
}
// Lower the score for matches that include the package name.
return pkgQualified, score * 0.8
}
}
// Now try matching the fully qualified symbol.
fullyQualified := []string{pkg.PackagePath(), ".", name}
idx, score := matcher(fullyQualified)
// As above, check if we matched just the unqualified symbol name.
nameStart := len(pkg.PackagePath()) + 1
if idx >= nameStart {
return []string{name}, score
}
// If our package path ends in the package name, we'll have skipped the
// initial pass above, so check if we matched just the package-qualified
// name.
if endsInPkgName && idx >= 0 {
pkgStart := len(pkg.PackagePath()) - len(pkg.PackageName())
if idx >= pkgStart {
return []string{pkg.PackageName(), ".", name}, score
}
}
// Our match was not contained within the unqualified or package qualified
// symbol. Return the fully qualified symbol but discount the score.
return fullyQualified, score * 0.6
}
func packageSymbolMatch(name string, pkg Metadata, matcher matcherFunc) ([]string, float64) {
qualified := []string{pkg.PackageName(), ".", name}
if _, s := matcher(qualified); s > 0 {
return qualified, s
}
return nil, 0
}
// symbolCollector holds context as we walk Packages, gathering symbols that
// match a given query.
//
// How we match symbols is parameterized by two interfaces:
// * A matcherFunc determines how well a string symbol matches a query. It
// returns a non-negative score indicating the quality of the match. A score
// of zero indicates no match.
// * A symbolizer determines how we extract the symbol for an object. This
// enables the 'symbolStyle' configuration option.
type symbolCollector struct {
// These types parameterize the symbol-matching pass.
matchers []matcherFunc
symbolizer symbolizer
seen map[span.URI]bool
symbolStore
}
func newSymbolCollector(matcher SymbolMatcher, style SymbolStyle, query string) *symbolCollector {
var s symbolizer
switch style {
case DynamicSymbols:
s = dynamicSymbolMatch
case FullyQualifiedSymbols:
s = fullyQualifiedSymbolMatch
case PackageQualifiedSymbols:
s = packageSymbolMatch
default:
panic(fmt.Errorf("unknown symbol style: %v", style))
}
sc := &symbolCollector{symbolizer: s}
sc.matchers = make([]matcherFunc, runtime.GOMAXPROCS(-1))
for i := range sc.matchers {
sc.matchers[i] = buildMatcher(matcher, query)
}
return sc
}
func buildMatcher(matcher SymbolMatcher, query string) matcherFunc {
switch matcher {
case SymbolFuzzy:
return parseQuery(query)
case SymbolFastFuzzy:
return fuzzy.NewSymbolMatcher(query).Match
case SymbolCaseSensitive:
return matchExact(query)
case SymbolCaseInsensitive:
q := strings.ToLower(query)
exact := matchExact(q)
wrapper := []string{""}
return func(chunks []string) (int, float64) {
s := strings.Join(chunks, "")
wrapper[0] = strings.ToLower(s)
return exact(wrapper)
}
}
panic(fmt.Errorf("unknown symbol matcher: %v", matcher))
}
// parseQuery parses a field-separated symbol query, extracting the special
// characters listed below, and returns a matcherFunc corresponding to the AND
// of all field queries.
//
// Special characters:
// ^ match exact prefix
// $ match exact suffix
// ' match exact
//
// In all three of these special queries, matches are 'smart-cased', meaning
// they are case sensitive if the symbol query contains any upper-case
// characters, and case insensitive otherwise.
func parseQuery(q string) matcherFunc {
fields := strings.Fields(q)
if len(fields) == 0 {
return func([]string) (int, float64) { return -1, 0 }
}
var funcs []matcherFunc
for _, field := range fields {
var f matcherFunc
switch {
case strings.HasPrefix(field, "^"):
prefix := field[1:]
f = smartCase(prefix, func(chunks []string) (int, float64) {
s := strings.Join(chunks, "")
if strings.HasPrefix(s, prefix) {
return 0, 1
}
return -1, 0
})
case strings.HasPrefix(field, "'"):
exact := field[1:]
f = smartCase(exact, matchExact(exact))
case strings.HasSuffix(field, "$"):
suffix := field[0 : len(field)-1]
f = smartCase(suffix, func(chunks []string) (int, float64) {
s := strings.Join(chunks, "")
if strings.HasSuffix(s, suffix) {
return len(s) - len(suffix), 1
}
return -1, 0
})
default:
fm := fuzzy.NewMatcher(field)
f = func(chunks []string) (int, float64) {
score := float64(fm.ScoreChunks(chunks))
ranges := fm.MatchedRanges()
if len(ranges) > 0 {
return ranges[0], score
}
return -1, score
}
}
funcs = append(funcs, f)
}
if len(funcs) == 1 {
return funcs[0]
}
return comboMatcher(funcs).match
}
func matchExact(exact string) matcherFunc {
return func(chunks []string) (int, float64) {
s := strings.Join(chunks, "")
if idx := strings.LastIndex(s, exact); idx >= 0 {
return idx, 1
}
return -1, 0
}
}
// smartCase returns a matcherFunc that is case-sensitive if q contains any
// upper-case characters, and case-insensitive otherwise.
func smartCase(q string, m matcherFunc) matcherFunc {
insensitive := strings.ToLower(q) == q
wrapper := []string{""}
return func(chunks []string) (int, float64) {
s := strings.Join(chunks, "")
if insensitive {
s = strings.ToLower(s)
}
wrapper[0] = s
return m(wrapper)
}
}
type comboMatcher []matcherFunc
func (c comboMatcher) match(chunks []string) (int, float64) {
score := 1.0
first := 0
for _, f := range c {
idx, s := f(chunks)
if idx < first {
first = idx
}
score *= s
}
return first, score
}
func (sc *symbolCollector) walk(ctx context.Context, views []View) ([]protocol.SymbolInformation, error) {
// Use the root view URIs for determining (lexically) whether a uri is in any
// open workspace.
var roots []string
for _, v := range views {
roots = append(roots, strings.TrimRight(string(v.Folder()), "/"))
}
results := make(chan *symbolStore)
matcherlen := len(sc.matchers)
files := make(map[span.URI]symbolFile)
for _, v := range views {
snapshot, release := v.Snapshot(ctx)
defer release()
psyms, err := snapshot.Symbols(ctx)
if err != nil {
return nil, err
}
filters := v.Options().DirectoryFilters
folder := filepath.ToSlash(v.Folder().Filename())
for uri, syms := range psyms {
norm := filepath.ToSlash(uri.Filename())
nm := strings.TrimPrefix(norm, folder)
if FiltersDisallow(nm, filters) {
continue
}
// Only scan each file once.
if _, ok := files[uri]; ok {
continue
}
mds, err := snapshot.MetadataForFile(ctx, uri)
if err != nil {
return nil, err
}
if len(mds) == 0 {
// TODO: should use the bug reporting API
continue
}
files[uri] = symbolFile{uri, mds[0], syms}
}
}
var work []symbolFile
for _, f := range files {
work = append(work, f)
}
// Compute matches concurrently. Each symbolWorker has its own symbolStore,
// which we merge at the end.
for i, matcher := range sc.matchers {
go func(i int, matcher matcherFunc) {
w := &symbolWorker{
symbolizer: sc.symbolizer,
matcher: matcher,
ss: &symbolStore{},
roots: roots,
}
for j := i; j < len(work); j += matcherlen {
w.matchFile(work[j])
}
results <- w.ss
}(i, matcher)
}
for i := 0; i < matcherlen; i++ {
ss := <-results
for _, si := range ss.res {
sc.store(si)
}
}
return sc.results(), nil
}
// FilterDisallow is code from the body of cache.pathExcludedByFilter in cache/view.go
// Exporting and using that function would cause an import cycle.
// Moving it here and exporting it would leave behind view_test.go.
// (This code is exported and used in the body of cache.pathExcludedByFilter)
func FiltersDisallow(path string, filters []string) bool {
path = strings.TrimPrefix(path, "/")
var excluded bool
for _, filter := range filters {
op, prefix := filter[0], filter[1:]
// Non-empty prefixes have to be precise directory matches.
if prefix != "" {
prefix = prefix + "/"
path = path + "/"
}
if !strings.HasPrefix(path, prefix) {
continue
}
excluded = op == '-'
}
return excluded
}
// symbolFile holds symbol information for a single file.
type symbolFile struct {
uri span.URI
md Metadata
syms []Symbol
}
// symbolWorker matches symbols and captures the highest scoring results.
type symbolWorker struct {
symbolizer symbolizer
matcher matcherFunc
ss *symbolStore
roots []string
}
func (w *symbolWorker) matchFile(i symbolFile) {
for _, sym := range i.syms {
symbolParts, score := w.symbolizer(sym.Name, i.md, w.matcher)
// Check if the score is too low before applying any downranking.
if w.ss.tooLow(score) {
continue
}
// Factors to apply to the match score for the purpose of downranking
// results.
//
// These numbers were crudely calibrated based on trial-and-error using a
// small number of sample queries. Adjust as necessary.
//
// All factors are multiplicative, meaning if more than one applies they are
// multiplied together.
const (
// nonWorkspaceFactor is applied to symbols outside of any active
// workspace. Developers are less likely to want to jump to code that they
// are not actively working on.
nonWorkspaceFactor = 0.5
// nonWorkspaceUnexportedFactor is applied to unexported symbols outside of
// any active workspace. Since one wouldn't usually jump to unexported
// symbols to understand a package API, they are particularly irrelevant.
nonWorkspaceUnexportedFactor = 0.5
// every field or method nesting level to access the field decreases
// the score by a factor of 1.0 - depth*depthFactor, up to a depth of
// 3.
depthFactor = 0.2
)
startWord := true
exported := true
depth := 0.0
for _, r := range sym.Name {
if startWord && !unicode.IsUpper(r) {
exported = false
}
if r == '.' {
startWord = true
depth++
} else {
startWord = false
}
}
inWorkspace := false
for _, root := range w.roots {
if strings.HasPrefix(string(i.uri), root) {
inWorkspace = true
break
}
}
// Apply downranking based on workspace position.
if !inWorkspace {
score *= nonWorkspaceFactor
if !exported {
score *= nonWorkspaceUnexportedFactor
}
}
// Apply downranking based on symbol depth.
if depth > 3 {
depth = 3
}
score *= 1.0 - depth*depthFactor
if w.ss.tooLow(score) {
continue
}
si := symbolInformation{
score: score,
symbol: strings.Join(symbolParts, ""),
kind: sym.Kind,
uri: i.uri,
rng: sym.Range,
container: i.md.PackagePath(),
}
w.ss.store(si)
}
}
type symbolStore struct {
res [maxSymbols]symbolInformation
}
// store inserts si into the sorted results, if si has a high enough score.
func (sc *symbolStore) store(si symbolInformation) {
if sc.tooLow(si.score) {
return
}
insertAt := sort.Search(len(sc.res), func(i int) bool {
return sc.res[i].score < si.score
})
if insertAt < len(sc.res)-1 {
copy(sc.res[insertAt+1:], sc.res[insertAt:len(sc.res)-1])
}
sc.res[insertAt] = si
}
func (sc *symbolStore) tooLow(score float64) bool {
return score <= sc.res[len(sc.res)-1].score
}
func (sc *symbolStore) results() []protocol.SymbolInformation {
var res []protocol.SymbolInformation
for _, si := range sc.res {
if si.score <= 0 {
return res
}
res = append(res, si.asProtocolSymbolInformation())
}
return res
}
func typeToKind(typ types.Type) protocol.SymbolKind {
switch typ := typ.Underlying().(type) {
case *types.Interface:
return protocol.Interface
case *types.Struct:
return protocol.Struct
case *types.Signature:
if typ.Recv() != nil {
return protocol.Method
}
return protocol.Function
case *types.Named:
return typeToKind(typ.Underlying())
case *types.Basic:
i := typ.Info()
switch {
case i&types.IsNumeric != 0:
return protocol.Number
case i&types.IsBoolean != 0:
return protocol.Boolean
case i&types.IsString != 0:
return protocol.String
}
}
return protocol.Variable
}
// symbolInformation is a cut-down version of protocol.SymbolInformation that
// allows struct values of this type to be used as map keys.
type symbolInformation struct {
score float64
symbol string
container string
kind protocol.SymbolKind
uri span.URI
rng protocol.Range
}
// asProtocolSymbolInformation converts s to a protocol.SymbolInformation value.
//
// TODO: work out how to handle tags if/when they are needed.
func (s symbolInformation) asProtocolSymbolInformation() protocol.SymbolInformation {
return protocol.SymbolInformation{
Name: s.symbol,
Kind: s.kind,
Location: protocol.Location{
URI: protocol.URIFromSpanURI(s.uri),
Range: s.rng,
},
ContainerName: s.container,
}
}