repo_cache_bug.go

  1package cache
  2
  3import (
  4	"bytes"
  5	"encoding/gob"
  6	"errors"
  7	"fmt"
  8	"sort"
  9	"strings"
 10	"time"
 11	"unicode/utf8"
 12
 13	"github.com/blevesearch/bleve"
 14
 15	"github.com/MichaelMure/git-bug/entities/bug"
 16	"github.com/MichaelMure/git-bug/entity"
 17	"github.com/MichaelMure/git-bug/query"
 18	"github.com/MichaelMure/git-bug/repository"
 19)
 20
 21const bugCacheFile = "bug-cache"
 22
 23var errBugNotInCache = errors.New("bug missing from cache")
 24
 25// bugUpdated is a callback to trigger when the excerpt of a bug changed,
 26// that is each time a bug is updated
 27func (c *RepoCache) bugUpdated(id entity.Id) error {
 28	c.muBug.Lock()
 29	b, ok := c.bugs[id]
 30	if !ok {
 31		c.muBug.Unlock()
 32
 33		// if the bug is not loaded at this point, it means it was loaded before
 34		// but got evicted. Which means we potentially have multiple copies in
 35		// memory and thus concurrent write.
 36		// Failing immediately here is the simple and safe solution to avoid
 37		// complicated data loss.
 38		return errBugNotInCache
 39	}
 40	c.loadedBugs.Get(id)
 41	c.bugExcerpts[id] = NewBugExcerpt(b.bug, b.Snapshot())
 42	c.muBug.Unlock()
 43
 44	if err := c.addBugToSearchIndex(b.Snapshot()); err != nil {
 45		return err
 46	}
 47
 48	// we only need to write the bug cache
 49	return c.writeBugCache()
 50}
 51
 52// load will try to read from the disk the bug cache file
 53func (c *RepoCache) loadBugCache() error {
 54	c.muBug.Lock()
 55	defer c.muBug.Unlock()
 56
 57	f, err := c.repo.LocalStorage().Open(bugCacheFile)
 58	if err != nil {
 59		return err
 60	}
 61
 62	decoder := gob.NewDecoder(f)
 63
 64	aux := struct {
 65		Version  uint
 66		Excerpts map[entity.Id]*BugExcerpt
 67	}{}
 68
 69	err = decoder.Decode(&aux)
 70	if err != nil {
 71		return err
 72	}
 73
 74	if aux.Version != formatVersion {
 75		return fmt.Errorf("unknown cache format version %v", aux.Version)
 76	}
 77
 78	c.bugExcerpts = aux.Excerpts
 79
 80	index, err := c.repo.GetBleveIndex("bug")
 81	if err != nil {
 82		return err
 83	}
 84
 85	// simple heuristic to detect a mismatch between the index and the bugs
 86	count, err := index.DocCount()
 87	if err != nil {
 88		return err
 89	}
 90	if count != uint64(len(c.bugExcerpts)) {
 91		return fmt.Errorf("count mismatch between bleve and bug excerpts")
 92	}
 93
 94	return nil
 95}
 96
 97// write will serialize on disk the bug cache file
 98func (c *RepoCache) writeBugCache() error {
 99	c.muBug.RLock()
100	defer c.muBug.RUnlock()
101
102	var data bytes.Buffer
103
104	aux := struct {
105		Version  uint
106		Excerpts map[entity.Id]*BugExcerpt
107	}{
108		Version:  formatVersion,
109		Excerpts: c.bugExcerpts,
110	}
111
112	encoder := gob.NewEncoder(&data)
113
114	err := encoder.Encode(aux)
115	if err != nil {
116		return err
117	}
118
119	f, err := c.repo.LocalStorage().Create(bugCacheFile)
120	if err != nil {
121		return err
122	}
123
124	_, err = f.Write(data.Bytes())
125	if err != nil {
126		return err
127	}
128
129	return f.Close()
130}
131
132// ResolveBugExcerpt retrieve a BugExcerpt matching the exact given id
133func (c *RepoCache) ResolveBugExcerpt(id entity.Id) (*BugExcerpt, error) {
134	c.muBug.RLock()
135	defer c.muBug.RUnlock()
136
137	excerpt, ok := c.bugExcerpts[id]
138	if !ok {
139		return nil, bug.ErrBugNotExist
140	}
141
142	return excerpt, nil
143}
144
145// ResolveBug retrieve a bug matching the exact given id
146func (c *RepoCache) ResolveBug(id entity.Id) (*BugCache, error) {
147	c.muBug.RLock()
148	cached, ok := c.bugs[id]
149	if ok {
150		c.loadedBugs.Get(id)
151		c.muBug.RUnlock()
152		return cached, nil
153	}
154	c.muBug.RUnlock()
155
156	b, err := bug.ReadWithResolver(c.repo, c.resolvers, id)
157	if err != nil {
158		return nil, err
159	}
160
161	cached = NewBugCache(c, b)
162
163	c.muBug.Lock()
164	c.bugs[id] = cached
165	c.loadedBugs.Add(id)
166	c.muBug.Unlock()
167
168	c.evictIfNeeded()
169
170	return cached, nil
171}
172
173// evictIfNeeded will evict a bug from the cache if needed
174// it also removes references of the bug from the bugs
175func (c *RepoCache) evictIfNeeded() {
176	c.muBug.Lock()
177	defer c.muBug.Unlock()
178	if c.loadedBugs.Len() <= c.maxLoadedBugs {
179		return
180	}
181
182	for _, id := range c.loadedBugs.GetOldestToNewest() {
183		b := c.bugs[id]
184		if b.NeedCommit() {
185			continue
186		}
187
188		b.mu.Lock()
189		c.loadedBugs.Remove(id)
190		delete(c.bugs, id)
191
192		if c.loadedBugs.Len() <= c.maxLoadedBugs {
193			return
194		}
195	}
196}
197
198// ResolveBugExcerptPrefix retrieve a BugExcerpt matching an id prefix. It fails if multiple
199// bugs match.
200func (c *RepoCache) ResolveBugExcerptPrefix(prefix string) (*BugExcerpt, error) {
201	return c.ResolveBugExcerptMatcher(func(excerpt *BugExcerpt) bool {
202		return excerpt.Id.HasPrefix(prefix)
203	})
204}
205
206// ResolveBugPrefix retrieve a bug matching an id prefix. It fails if multiple
207// bugs match.
208func (c *RepoCache) ResolveBugPrefix(prefix string) (*BugCache, error) {
209	return c.ResolveBugMatcher(func(excerpt *BugExcerpt) bool {
210		return excerpt.Id.HasPrefix(prefix)
211	})
212}
213
214// ResolveBugCreateMetadata retrieve a bug that has the exact given metadata on
215// its Create operation, that is, the first operation. It fails if multiple bugs
216// match.
217func (c *RepoCache) ResolveBugCreateMetadata(key string, value string) (*BugCache, error) {
218	return c.ResolveBugMatcher(func(excerpt *BugExcerpt) bool {
219		return excerpt.CreateMetadata[key] == value
220	})
221}
222
223func (c *RepoCache) ResolveBugExcerptMatcher(f func(*BugExcerpt) bool) (*BugExcerpt, error) {
224	id, err := c.resolveBugMatcher(f)
225	if err != nil {
226		return nil, err
227	}
228	return c.ResolveBugExcerpt(id)
229}
230
231func (c *RepoCache) ResolveBugMatcher(f func(*BugExcerpt) bool) (*BugCache, error) {
232	id, err := c.resolveBugMatcher(f)
233	if err != nil {
234		return nil, err
235	}
236	return c.ResolveBug(id)
237}
238
239func (c *RepoCache) resolveBugMatcher(f func(*BugExcerpt) bool) (entity.Id, error) {
240	c.muBug.RLock()
241	defer c.muBug.RUnlock()
242
243	// preallocate but empty
244	matching := make([]entity.Id, 0, 5)
245
246	for _, excerpt := range c.bugExcerpts {
247		if f(excerpt) {
248			matching = append(matching, excerpt.Id)
249		}
250	}
251
252	if len(matching) > 1 {
253		return entity.UnsetId, bug.NewErrMultipleMatchBug(matching)
254	}
255
256	if len(matching) == 0 {
257		return entity.UnsetId, bug.ErrBugNotExist
258	}
259
260	return matching[0], nil
261}
262
263// ResolveComment search for a Bug/Comment combination matching the merged
264// bug/comment Id prefix. Returns the Bug containing the Comment and the Comment's
265// Id.
266func (c *RepoCache) ResolveComment(prefix string) (*BugCache, entity.CombinedId, error) {
267	bugPrefix, _ := entity.SeparateIds(prefix)
268	bugCandidate := make([]entity.Id, 0, 5)
269
270	// build a list of possible matching bugs
271	c.muBug.RLock()
272	for _, excerpt := range c.bugExcerpts {
273		if excerpt.Id.HasPrefix(bugPrefix) {
274			bugCandidate = append(bugCandidate, excerpt.Id)
275		}
276	}
277	c.muBug.RUnlock()
278
279	matchingBugIds := make([]entity.Id, 0, 5)
280	matchingCommentId := entity.UnsetCombinedId
281	var matchingBug *BugCache
282
283	// search for matching comments
284	// searching every bug candidate allow for some collision with the bug prefix only,
285	// before being refined with the full comment prefix
286	for _, bugId := range bugCandidate {
287		b, err := c.ResolveBug(bugId)
288		if err != nil {
289			return nil, entity.UnsetCombinedId, err
290		}
291
292		for _, comment := range b.Snapshot().Comments {
293			if comment.TargetId().HasPrefix(prefix) {
294				matchingBugIds = append(matchingBugIds, bugId)
295				matchingBug = b
296				matchingCommentId = comment.CombinedId()
297			}
298		}
299	}
300
301	if len(matchingBugIds) > 1 {
302		return nil, entity.UnsetCombinedId, entity.NewErrMultipleMatch("bug/comment", matchingBugIds)
303	} else if len(matchingBugIds) == 0 {
304		return nil, entity.UnsetCombinedId, errors.New("comment doesn't exist")
305	}
306
307	return matchingBug, matchingCommentId, nil
308}
309
310// QueryBugs return the id of all Bug matching the given Query
311func (c *RepoCache) QueryBugs(q *query.Query) ([]entity.Id, error) {
312	c.muBug.RLock()
313	defer c.muBug.RUnlock()
314
315	if q == nil {
316		return c.AllBugsIds(), nil
317	}
318
319	matcher := compileMatcher(q.Filters)
320
321	var filtered []*BugExcerpt
322	var foundBySearch map[entity.Id]*BugExcerpt
323
324	if q.Search != nil {
325		foundBySearch = map[entity.Id]*BugExcerpt{}
326
327		terms := make([]string, len(q.Search))
328		copy(terms, q.Search)
329		for i, search := range q.Search {
330			if strings.Contains(search, " ") {
331				terms[i] = fmt.Sprintf("\"%s\"", search)
332			}
333		}
334
335		bleveQuery := bleve.NewQueryStringQuery(strings.Join(terms, " "))
336		bleveSearch := bleve.NewSearchRequest(bleveQuery)
337
338		index, err := c.repo.GetBleveIndex("bug")
339		if err != nil {
340			return nil, err
341		}
342
343		searchResults, err := index.Search(bleveSearch)
344		if err != nil {
345			return nil, err
346		}
347
348		for _, hit := range searchResults.Hits {
349			foundBySearch[entity.Id(hit.ID)] = c.bugExcerpts[entity.Id(hit.ID)]
350		}
351	} else {
352		foundBySearch = c.bugExcerpts
353	}
354
355	for _, excerpt := range foundBySearch {
356		if matcher.Match(excerpt, c) {
357			filtered = append(filtered, excerpt)
358		}
359	}
360
361	var sorter sort.Interface
362
363	switch q.OrderBy {
364	case query.OrderById:
365		sorter = BugsById(filtered)
366	case query.OrderByCreation:
367		sorter = BugsByCreationTime(filtered)
368	case query.OrderByEdit:
369		sorter = BugsByEditTime(filtered)
370	default:
371		return nil, errors.New("missing sort type")
372	}
373
374	switch q.OrderDirection {
375	case query.OrderAscending:
376		// Nothing to do
377	case query.OrderDescending:
378		sorter = sort.Reverse(sorter)
379	default:
380		return nil, errors.New("missing sort direction")
381	}
382
383	sort.Sort(sorter)
384
385	result := make([]entity.Id, len(filtered))
386
387	for i, val := range filtered {
388		result[i] = val.Id
389	}
390
391	return result, nil
392}
393
394// AllBugsIds return all known bug ids
395func (c *RepoCache) AllBugsIds() []entity.Id {
396	c.muBug.RLock()
397	defer c.muBug.RUnlock()
398
399	result := make([]entity.Id, len(c.bugExcerpts))
400
401	i := 0
402	for _, excerpt := range c.bugExcerpts {
403		result[i] = excerpt.Id
404		i++
405	}
406
407	return result
408}
409
410// ValidLabels list valid labels
411//
412// Note: in the future, a proper label policy could be implemented where valid
413// labels are defined in a configuration file. Until that, the default behavior
414// is to return the list of labels already used.
415func (c *RepoCache) ValidLabels() []bug.Label {
416	c.muBug.RLock()
417	defer c.muBug.RUnlock()
418
419	set := map[bug.Label]interface{}{}
420
421	for _, excerpt := range c.bugExcerpts {
422		for _, l := range excerpt.Labels {
423			set[l] = nil
424		}
425	}
426
427	result := make([]bug.Label, len(set))
428
429	i := 0
430	for l := range set {
431		result[i] = l
432		i++
433	}
434
435	// Sort
436	sort.Slice(result, func(i, j int) bool {
437		return string(result[i]) < string(result[j])
438	})
439
440	return result
441}
442
443// NewBug create a new bug
444// The new bug is written in the repository (commit)
445func (c *RepoCache) NewBug(title string, message string) (*BugCache, *bug.CreateOperation, error) {
446	return c.NewBugWithFiles(title, message, nil)
447}
448
449// NewBugWithFiles create a new bug with attached files for the message
450// The new bug is written in the repository (commit)
451func (c *RepoCache) NewBugWithFiles(title string, message string, files []repository.Hash) (*BugCache, *bug.CreateOperation, error) {
452	author, err := c.GetUserIdentity()
453	if err != nil {
454		return nil, nil, err
455	}
456
457	return c.NewBugRaw(author, time.Now().Unix(), title, message, files, nil)
458}
459
460// NewBugRaw create a new bug with attached files for the message, as
461// well as metadata for the Create operation.
462// The new bug is written in the repository (commit)
463func (c *RepoCache) NewBugRaw(author *IdentityCache, unixTime int64, title string, message string, files []repository.Hash, metadata map[string]string) (*BugCache, *bug.CreateOperation, error) {
464	b, op, err := bug.Create(author.Identity, unixTime, title, message, files, metadata)
465	if err != nil {
466		return nil, nil, err
467	}
468
469	err = b.Commit(c.repo)
470	if err != nil {
471		return nil, nil, err
472	}
473
474	c.muBug.Lock()
475	if _, has := c.bugs[b.Id()]; has {
476		c.muBug.Unlock()
477		return nil, nil, fmt.Errorf("bug %s already exist in the cache", b.Id())
478	}
479
480	cached := NewBugCache(c, b)
481	c.bugs[b.Id()] = cached
482	c.loadedBugs.Add(b.Id())
483	c.muBug.Unlock()
484
485	c.evictIfNeeded()
486
487	// force the write of the excerpt
488	err = c.bugUpdated(b.Id())
489	if err != nil {
490		return nil, nil, err
491	}
492
493	return cached, op, nil
494}
495
496// RemoveBug removes a bug from the cache and repo given a bug id prefix
497func (c *RepoCache) RemoveBug(prefix string) error {
498	b, err := c.ResolveBugPrefix(prefix)
499	if err != nil {
500		return err
501	}
502
503	c.muBug.Lock()
504	err = bug.RemoveBug(c.repo, b.Id())
505
506	delete(c.bugs, b.Id())
507	delete(c.bugExcerpts, b.Id())
508	c.loadedBugs.Remove(b.Id())
509
510	c.muBug.Unlock()
511
512	return c.writeBugCache()
513}
514
515func (c *RepoCache) addBugToSearchIndex(snap *bug.Snapshot) error {
516	searchableBug := struct {
517		Text []string
518	}{}
519
520	// See https://github.com/blevesearch/bleve/issues/1576
521	var sb strings.Builder
522	normalize := func(text string) string {
523		sb.Reset()
524		for _, field := range strings.Fields(text) {
525			if utf8.RuneCountInString(field) < 100 {
526				sb.WriteString(field)
527				sb.WriteRune(' ')
528			}
529		}
530		return sb.String()
531	}
532
533	for _, comment := range snap.Comments {
534		searchableBug.Text = append(searchableBug.Text, normalize(comment.Message))
535	}
536
537	searchableBug.Text = append(searchableBug.Text, normalize(snap.Title))
538
539	index, err := c.repo.GetBleveIndex("bug")
540	if err != nil {
541		return err
542	}
543
544	err = index.Index(snap.Id().String(), searchableBug)
545	if err != nil {
546		return err
547	}
548
549	return nil
550}