repo_cache.go

  1package cache
  2
  3import (
  4	"bytes"
  5	"encoding/gob"
  6	"fmt"
  7	"io"
  8	"io/ioutil"
  9	"os"
 10	"path"
 11	"sort"
 12	"strconv"
 13	"time"
 14
 15	"github.com/pkg/errors"
 16
 17	"github.com/MichaelMure/git-bug/bug"
 18	"github.com/MichaelMure/git-bug/entity"
 19	"github.com/MichaelMure/git-bug/identity"
 20	"github.com/MichaelMure/git-bug/repository"
 21	"github.com/MichaelMure/git-bug/util/git"
 22	"github.com/MichaelMure/git-bug/util/process"
 23)
 24
 25const bugCacheFile = "bug-cache"
 26const identityCacheFile = "identity-cache"
 27
 28// 1: original format
 29// 2: added cache for identities with a reference in the bug cache
 30const formatVersion = 2
 31
 32type ErrInvalidCacheFormat struct {
 33	message string
 34}
 35
 36func (e ErrInvalidCacheFormat) Error() string {
 37	return e.message
 38}
 39
 40var _ repository.RepoCommon = &RepoCache{}
 41
 42// RepoCache is a cache for a Repository. This cache has multiple functions:
 43//
 44// 1. After being loaded, a Bug is kept in memory in the cache, allowing for fast
 45// 		access later.
 46// 2. The cache maintain in memory and on disk a pre-digested excerpt for each bug,
 47// 		allowing for fast querying the whole set of bugs without having to load
 48//		them individually.
 49// 3. The cache guarantee that a single instance of a Bug is loaded at once, avoiding
 50// 		loss of data that we could have with multiple copies in the same process.
 51// 4. The same way, the cache maintain in memory a single copy of the loaded identities.
 52//
 53// The cache also protect the on-disk data by locking the git repository for its
 54// own usage, by writing a lock file. Of course, normal git operations are not
 55// affected, only git-bug related one.
 56type RepoCache struct {
 57	// the underlying repo
 58	repo repository.ClockedRepo
 59
 60	// excerpt of bugs data for all bugs
 61	bugExcerpts map[entity.Id]*BugExcerpt
 62	// bug loaded in memory
 63	bugs map[entity.Id]*BugCache
 64
 65	// excerpt of identities data for all identities
 66	identitiesExcerpts map[entity.Id]*IdentityExcerpt
 67	// identities loaded in memory
 68	identities map[entity.Id]*IdentityCache
 69
 70	// the user identity's id, if known
 71	userIdentityId entity.Id
 72}
 73
 74func NewRepoCache(r repository.ClockedRepo) (*RepoCache, error) {
 75	c := &RepoCache{
 76		repo:       r,
 77		bugs:       make(map[entity.Id]*BugCache),
 78		identities: make(map[entity.Id]*IdentityCache),
 79	}
 80
 81	err := c.lock()
 82	if err != nil {
 83		return &RepoCache{}, err
 84	}
 85
 86	err = c.load()
 87	if err == nil {
 88		return c, nil
 89	}
 90	if _, ok := err.(ErrInvalidCacheFormat); ok {
 91		return nil, err
 92	}
 93
 94	err = c.buildCache()
 95	if err != nil {
 96		return nil, err
 97	}
 98
 99	return c, c.write()
100}
101
102// LocalConfig give access to the repository scoped configuration
103func (c *RepoCache) LocalConfig() repository.Config {
104	return c.repo.LocalConfig()
105}
106
107// GlobalConfig give access to the git global configuration
108func (c *RepoCache) GlobalConfig() repository.Config {
109	return c.repo.GlobalConfig()
110}
111
112// GetPath returns the path to the repo.
113func (c *RepoCache) GetPath() string {
114	return c.repo.GetPath()
115}
116
117// GetCoreEditor returns the name of the editor that the user has used to configure git.
118func (c *RepoCache) GetCoreEditor() (string, error) {
119	return c.repo.GetCoreEditor()
120}
121
122// GetRemotes returns the configured remotes repositories.
123func (c *RepoCache) GetRemotes() (map[string]string, error) {
124	return c.repo.GetRemotes()
125}
126
127// GetUserName returns the name the the user has used to configure git
128func (c *RepoCache) GetUserName() (string, error) {
129	return c.repo.GetUserName()
130}
131
132// GetUserEmail returns the email address that the user has used to configure git.
133func (c *RepoCache) GetUserEmail() (string, error) {
134	return c.repo.GetUserEmail()
135}
136
137func (c *RepoCache) lock() error {
138	lockPath := repoLockFilePath(c.repo)
139
140	err := repoIsAvailable(c.repo)
141	if err != nil {
142		return err
143	}
144
145	f, err := os.Create(lockPath)
146	if err != nil {
147		return err
148	}
149
150	pid := fmt.Sprintf("%d", os.Getpid())
151	_, err = f.WriteString(pid)
152	if err != nil {
153		return err
154	}
155
156	return f.Close()
157}
158
159func (c *RepoCache) Close() error {
160	c.identities = make(map[entity.Id]*IdentityCache)
161	c.identitiesExcerpts = nil
162	c.bugs = make(map[entity.Id]*BugCache)
163	c.bugExcerpts = nil
164
165	lockPath := repoLockFilePath(c.repo)
166	return os.Remove(lockPath)
167}
168
169// bugUpdated is a callback to trigger when the excerpt of a bug changed,
170// that is each time a bug is updated
171func (c *RepoCache) bugUpdated(id entity.Id) error {
172	b, ok := c.bugs[id]
173	if !ok {
174		panic("missing bug in the cache")
175	}
176
177	c.bugExcerpts[id] = NewBugExcerpt(b.bug, b.Snapshot())
178
179	// we only need to write the bug cache
180	return c.writeBugCache()
181}
182
183// identityUpdated is a callback to trigger when the excerpt of an identity
184// changed, that is each time an identity is updated
185func (c *RepoCache) identityUpdated(id entity.Id) error {
186	i, ok := c.identities[id]
187	if !ok {
188		panic("missing identity in the cache")
189	}
190
191	c.identitiesExcerpts[id] = NewIdentityExcerpt(i.Identity)
192
193	// we only need to write the identity cache
194	return c.writeIdentityCache()
195}
196
197// load will try to read from the disk all the cache files
198func (c *RepoCache) load() error {
199	err := c.loadBugCache()
200	if err != nil {
201		return err
202	}
203	return c.loadIdentityCache()
204}
205
206// load will try to read from the disk the bug cache file
207func (c *RepoCache) loadBugCache() error {
208	f, err := os.Open(bugCacheFilePath(c.repo))
209	if err != nil {
210		return err
211	}
212
213	decoder := gob.NewDecoder(f)
214
215	aux := struct {
216		Version  uint
217		Excerpts map[entity.Id]*BugExcerpt
218	}{}
219
220	err = decoder.Decode(&aux)
221	if err != nil {
222		return err
223	}
224
225	if aux.Version != 2 {
226		return ErrInvalidCacheFormat{
227			message: fmt.Sprintf("unknown cache format version %v", aux.Version),
228		}
229	}
230
231	c.bugExcerpts = aux.Excerpts
232	return nil
233}
234
235// load will try to read from the disk the identity cache file
236func (c *RepoCache) loadIdentityCache() error {
237	f, err := os.Open(identityCacheFilePath(c.repo))
238	if err != nil {
239		return err
240	}
241
242	decoder := gob.NewDecoder(f)
243
244	aux := struct {
245		Version  uint
246		Excerpts map[entity.Id]*IdentityExcerpt
247	}{}
248
249	err = decoder.Decode(&aux)
250	if err != nil {
251		return err
252	}
253
254	if aux.Version != 2 {
255		return ErrInvalidCacheFormat{
256			message: fmt.Sprintf("unknown cache format version %v", aux.Version),
257		}
258	}
259
260	c.identitiesExcerpts = aux.Excerpts
261	return nil
262}
263
264// write will serialize on disk all the cache files
265func (c *RepoCache) write() error {
266	err := c.writeBugCache()
267	if err != nil {
268		return err
269	}
270	return c.writeIdentityCache()
271}
272
273// write will serialize on disk the bug cache file
274func (c *RepoCache) writeBugCache() error {
275	var data bytes.Buffer
276
277	aux := struct {
278		Version  uint
279		Excerpts map[entity.Id]*BugExcerpt
280	}{
281		Version:  formatVersion,
282		Excerpts: c.bugExcerpts,
283	}
284
285	encoder := gob.NewEncoder(&data)
286
287	err := encoder.Encode(aux)
288	if err != nil {
289		return err
290	}
291
292	f, err := os.Create(bugCacheFilePath(c.repo))
293	if err != nil {
294		return err
295	}
296
297	_, err = f.Write(data.Bytes())
298	if err != nil {
299		return err
300	}
301
302	return f.Close()
303}
304
305// write will serialize on disk the identity cache file
306func (c *RepoCache) writeIdentityCache() error {
307	var data bytes.Buffer
308
309	aux := struct {
310		Version  uint
311		Excerpts map[entity.Id]*IdentityExcerpt
312	}{
313		Version:  formatVersion,
314		Excerpts: c.identitiesExcerpts,
315	}
316
317	encoder := gob.NewEncoder(&data)
318
319	err := encoder.Encode(aux)
320	if err != nil {
321		return err
322	}
323
324	f, err := os.Create(identityCacheFilePath(c.repo))
325	if err != nil {
326		return err
327	}
328
329	_, err = f.Write(data.Bytes())
330	if err != nil {
331		return err
332	}
333
334	return f.Close()
335}
336
337func bugCacheFilePath(repo repository.Repo) string {
338	return path.Join(repo.GetPath(), "git-bug", bugCacheFile)
339}
340
341func identityCacheFilePath(repo repository.Repo) string {
342	return path.Join(repo.GetPath(), "git-bug", identityCacheFile)
343}
344
345func (c *RepoCache) buildCache() error {
346	_, _ = fmt.Fprintf(os.Stderr, "Building identity cache... ")
347
348	c.identitiesExcerpts = make(map[entity.Id]*IdentityExcerpt)
349
350	allIdentities := identity.ReadAllLocalIdentities(c.repo)
351
352	for i := range allIdentities {
353		if i.Err != nil {
354			return i.Err
355		}
356
357		c.identitiesExcerpts[i.Identity.Id()] = NewIdentityExcerpt(i.Identity)
358	}
359
360	_, _ = fmt.Fprintln(os.Stderr, "Done.")
361
362	_, _ = fmt.Fprintf(os.Stderr, "Building bug cache... ")
363
364	c.bugExcerpts = make(map[entity.Id]*BugExcerpt)
365
366	allBugs := bug.ReadAllLocalBugs(c.repo)
367
368	for b := range allBugs {
369		if b.Err != nil {
370			return b.Err
371		}
372
373		snap := b.Bug.Compile()
374		c.bugExcerpts[b.Bug.Id()] = NewBugExcerpt(b.Bug, &snap)
375	}
376
377	_, _ = fmt.Fprintln(os.Stderr, "Done.")
378	return nil
379}
380
381// ResolveBugExcerpt retrieve a BugExcerpt matching the exact given id
382func (c *RepoCache) ResolveBugExcerpt(id entity.Id) (*BugExcerpt, error) {
383	e, ok := c.bugExcerpts[id]
384	if !ok {
385		return nil, bug.ErrBugNotExist
386	}
387
388	return e, nil
389}
390
391// ResolveBug retrieve a bug matching the exact given id
392func (c *RepoCache) ResolveBug(id entity.Id) (*BugCache, error) {
393	cached, ok := c.bugs[id]
394	if ok {
395		return cached, nil
396	}
397
398	b, err := bug.ReadLocalBug(c.repo, id)
399	if err != nil {
400		return nil, err
401	}
402
403	cached = NewBugCache(c, b)
404	c.bugs[id] = cached
405
406	return cached, nil
407}
408
409// ResolveBugExcerptPrefix retrieve a BugExcerpt matching an id prefix. It fails if multiple
410// bugs match.
411func (c *RepoCache) ResolveBugExcerptPrefix(prefix string) (*BugExcerpt, error) {
412	return c.ResolveBugExcerptMatcher(func(excerpt *BugExcerpt) bool {
413		return excerpt.Id.HasPrefix(prefix)
414	})
415}
416
417// ResolveBugPrefix retrieve a bug matching an id prefix. It fails if multiple
418// bugs match.
419func (c *RepoCache) ResolveBugPrefix(prefix string) (*BugCache, error) {
420	return c.ResolveBugMatcher(func(excerpt *BugExcerpt) bool {
421		return excerpt.Id.HasPrefix(prefix)
422	})
423}
424
425// ResolveBugCreateMetadata retrieve a bug that has the exact given metadata on
426// its Create operation, that is, the first operation. It fails if multiple bugs
427// match.
428func (c *RepoCache) ResolveBugCreateMetadata(key string, value string) (*BugCache, error) {
429	return c.ResolveBugMatcher(func(excerpt *BugExcerpt) bool {
430		return excerpt.CreateMetadata[key] == value
431	})
432}
433
434func (c *RepoCache) ResolveBugExcerptMatcher(f func(*BugExcerpt) bool) (*BugExcerpt, error) {
435	id, err := c.resolveBugMatcher(f)
436	if err != nil {
437		return nil, err
438	}
439	return c.ResolveBugExcerpt(id)
440}
441
442func (c *RepoCache) ResolveBugMatcher(f func(*BugExcerpt) bool) (*BugCache, error) {
443	id, err := c.resolveBugMatcher(f)
444	if err != nil {
445		return nil, err
446	}
447	return c.ResolveBug(id)
448}
449
450func (c *RepoCache) resolveBugMatcher(f func(*BugExcerpt) bool) (entity.Id, error) {
451	// preallocate but empty
452	matching := make([]entity.Id, 0, 5)
453
454	for _, excerpt := range c.bugExcerpts {
455		if f(excerpt) {
456			matching = append(matching, excerpt.Id)
457		}
458	}
459
460	if len(matching) > 1 {
461		return entity.UnsetId, bug.NewErrMultipleMatchBug(matching)
462	}
463
464	if len(matching) == 0 {
465		return entity.UnsetId, bug.ErrBugNotExist
466	}
467
468	return matching[0], nil
469}
470
471// QueryBugs return the id of all Bug matching the given Query
472func (c *RepoCache) QueryBugs(query *Query) []entity.Id {
473	if query == nil {
474		return c.AllBugsIds()
475	}
476
477	var filtered []*BugExcerpt
478
479	for _, excerpt := range c.bugExcerpts {
480		if query.Match(c, excerpt) {
481			filtered = append(filtered, excerpt)
482		}
483	}
484
485	var sorter sort.Interface
486
487	switch query.OrderBy {
488	case OrderById:
489		sorter = BugsById(filtered)
490	case OrderByCreation:
491		sorter = BugsByCreationTime(filtered)
492	case OrderByEdit:
493		sorter = BugsByEditTime(filtered)
494	default:
495		panic("missing sort type")
496	}
497
498	if query.OrderDirection == OrderDescending {
499		sorter = sort.Reverse(sorter)
500	}
501
502	sort.Sort(sorter)
503
504	result := make([]entity.Id, len(filtered))
505
506	for i, val := range filtered {
507		result[i] = val.Id
508	}
509
510	return result
511}
512
513// AllBugsIds return all known bug ids
514func (c *RepoCache) AllBugsIds() []entity.Id {
515	result := make([]entity.Id, len(c.bugExcerpts))
516
517	i := 0
518	for _, excerpt := range c.bugExcerpts {
519		result[i] = excerpt.Id
520		i++
521	}
522
523	return result
524}
525
526// ValidLabels list valid labels
527//
528// Note: in the future, a proper label policy could be implemented where valid
529// labels are defined in a configuration file. Until that, the default behavior
530// is to return the list of labels already used.
531func (c *RepoCache) ValidLabels() []bug.Label {
532	set := map[bug.Label]interface{}{}
533
534	for _, excerpt := range c.bugExcerpts {
535		for _, l := range excerpt.Labels {
536			set[l] = nil
537		}
538	}
539
540	result := make([]bug.Label, len(set))
541
542	i := 0
543	for l := range set {
544		result[i] = l
545		i++
546	}
547
548	// Sort
549	sort.Slice(result, func(i, j int) bool {
550		return string(result[i]) < string(result[j])
551	})
552
553	return result
554}
555
556// NewBug create a new bug
557// The new bug is written in the repository (commit)
558func (c *RepoCache) NewBug(title string, message string) (*BugCache, *bug.CreateOperation, error) {
559	return c.NewBugWithFiles(title, message, nil)
560}
561
562// NewBugWithFiles create a new bug with attached files for the message
563// The new bug is written in the repository (commit)
564func (c *RepoCache) NewBugWithFiles(title string, message string, files []git.Hash) (*BugCache, *bug.CreateOperation, error) {
565	author, err := c.GetUserIdentity()
566	if err != nil {
567		return nil, nil, err
568	}
569
570	return c.NewBugRaw(author, time.Now().Unix(), title, message, files, nil)
571}
572
573// NewBugWithFilesMeta create a new bug with attached files for the message, as
574// well as metadata for the Create operation.
575// The new bug is written in the repository (commit)
576func (c *RepoCache) NewBugRaw(author *IdentityCache, unixTime int64, title string, message string, files []git.Hash, metadata map[string]string) (*BugCache, *bug.CreateOperation, error) {
577	b, op, err := bug.CreateWithFiles(author.Identity, unixTime, title, message, files)
578	if err != nil {
579		return nil, nil, err
580	}
581
582	for key, value := range metadata {
583		op.SetMetadata(key, value)
584	}
585
586	err = b.Commit(c.repo)
587	if err != nil {
588		return nil, nil, err
589	}
590
591	if _, has := c.bugs[b.Id()]; has {
592		return nil, nil, fmt.Errorf("bug %s already exist in the cache", b.Id())
593	}
594
595	cached := NewBugCache(c, b)
596	c.bugs[b.Id()] = cached
597
598	// force the write of the excerpt
599	err = c.bugUpdated(b.Id())
600	if err != nil {
601		return nil, nil, err
602	}
603
604	return cached, op, nil
605}
606
607// Fetch retrieve updates from a remote
608// This does not change the local bugs or identities state
609func (c *RepoCache) Fetch(remote string) (string, error) {
610	stdout1, err := identity.Fetch(c.repo, remote)
611	if err != nil {
612		return stdout1, err
613	}
614
615	stdout2, err := bug.Fetch(c.repo, remote)
616	if err != nil {
617		return stdout2, err
618	}
619
620	return stdout1 + stdout2, nil
621}
622
623// MergeAll will merge all the available remote bug and identities
624func (c *RepoCache) MergeAll(remote string) <-chan entity.MergeResult {
625	out := make(chan entity.MergeResult)
626
627	// Intercept merge results to update the cache properly
628	go func() {
629		defer close(out)
630
631		results := identity.MergeAll(c.repo, remote)
632		for result := range results {
633			out <- result
634
635			if result.Err != nil {
636				continue
637			}
638
639			switch result.Status {
640			case entity.MergeStatusNew, entity.MergeStatusUpdated:
641				i := result.Entity.(*identity.Identity)
642				c.identitiesExcerpts[result.Id] = NewIdentityExcerpt(i)
643			}
644		}
645
646		results = bug.MergeAll(c.repo, remote)
647		for result := range results {
648			out <- result
649
650			if result.Err != nil {
651				continue
652			}
653
654			switch result.Status {
655			case entity.MergeStatusNew, entity.MergeStatusUpdated:
656				b := result.Entity.(*bug.Bug)
657				snap := b.Compile()
658				c.bugExcerpts[result.Id] = NewBugExcerpt(b, &snap)
659			}
660		}
661
662		err := c.write()
663
664		// No easy way out here ..
665		if err != nil {
666			panic(err)
667		}
668	}()
669
670	return out
671}
672
673// Push update a remote with the local changes
674func (c *RepoCache) Push(remote string) (string, error) {
675	stdout1, err := identity.Push(c.repo, remote)
676	if err != nil {
677		return stdout1, err
678	}
679
680	stdout2, err := bug.Push(c.repo, remote)
681	if err != nil {
682		return stdout2, err
683	}
684
685	return stdout1 + stdout2, nil
686}
687
688// Pull will do a Fetch + MergeAll
689// This function will return an error if a merge fail
690func (c *RepoCache) Pull(remote string) error {
691	_, err := c.Fetch(remote)
692	if err != nil {
693		return err
694	}
695
696	for merge := range c.MergeAll(remote) {
697		if merge.Err != nil {
698			return merge.Err
699		}
700		if merge.Status == entity.MergeStatusInvalid {
701			return errors.Errorf("merge failure: %s", merge.Reason)
702		}
703	}
704
705	return nil
706}
707
708func repoLockFilePath(repo repository.Repo) string {
709	return path.Join(repo.GetPath(), "git-bug", lockfile)
710}
711
712// repoIsAvailable check is the given repository is locked by a Cache.
713// Note: this is a smart function that will cleanup the lock file if the
714// corresponding process is not there anymore.
715// If no error is returned, the repo is free to edit.
716func repoIsAvailable(repo repository.Repo) error {
717	lockPath := repoLockFilePath(repo)
718
719	// Todo: this leave way for a racey access to the repo between the test
720	// if the file exist and the actual write. It's probably not a problem in
721	// practice because using a repository will be done from user interaction
722	// or in a context where a single instance of git-bug is already guaranteed
723	// (say, a server with the web UI running). But still, that might be nice to
724	// have a mutex or something to guard that.
725
726	// Todo: this will fail if somehow the filesystem is shared with another
727	// computer. Should add a configuration that prevent the cleaning of the
728	// lock file
729
730	f, err := os.Open(lockPath)
731
732	if err != nil && !os.IsNotExist(err) {
733		return err
734	}
735
736	if err == nil {
737		// lock file already exist
738		buf, err := ioutil.ReadAll(io.LimitReader(f, 10))
739		if err != nil {
740			return err
741		}
742		if len(buf) == 10 {
743			return fmt.Errorf("the lock file should be < 10 bytes")
744		}
745
746		pid, err := strconv.Atoi(string(buf))
747		if err != nil {
748			return err
749		}
750
751		if process.IsRunning(pid) {
752			return fmt.Errorf("the repository you want to access is already locked by the process pid %d", pid)
753		}
754
755		// The lock file is just laying there after a crash, clean it
756
757		fmt.Println("A lock file is present but the corresponding process is not, removing it.")
758		err = f.Close()
759		if err != nil {
760			return err
761		}
762
763		err = os.Remove(lockPath)
764		if err != nil {
765			return err
766		}
767	}
768
769	return nil
770}
771
772// ResolveIdentityExcerpt retrieve a IdentityExcerpt matching the exact given id
773func (c *RepoCache) ResolveIdentityExcerpt(id entity.Id) (*IdentityExcerpt, error) {
774	e, ok := c.identitiesExcerpts[id]
775	if !ok {
776		return nil, identity.ErrIdentityNotExist
777	}
778
779	return e, nil
780}
781
782// ResolveIdentity retrieve an identity matching the exact given id
783func (c *RepoCache) ResolveIdentity(id entity.Id) (*IdentityCache, error) {
784	cached, ok := c.identities[id]
785	if ok {
786		return cached, nil
787	}
788
789	i, err := identity.ReadLocal(c.repo, id)
790	if err != nil {
791		return nil, err
792	}
793
794	cached = NewIdentityCache(c, i)
795	c.identities[id] = cached
796
797	return cached, nil
798}
799
800// ResolveIdentityExcerptPrefix retrieve a IdentityExcerpt matching an id prefix.
801// It fails if multiple identities match.
802func (c *RepoCache) ResolveIdentityExcerptPrefix(prefix string) (*IdentityExcerpt, error) {
803	return c.ResolveIdentityExcerptMatcher(func(excerpt *IdentityExcerpt) bool {
804		return excerpt.Id.HasPrefix(prefix)
805	})
806}
807
808// ResolveIdentityPrefix retrieve an Identity matching an id prefix.
809// It fails if multiple identities match.
810func (c *RepoCache) ResolveIdentityPrefix(prefix string) (*IdentityCache, error) {
811	return c.ResolveIdentityMatcher(func(excerpt *IdentityExcerpt) bool {
812		return excerpt.Id.HasPrefix(prefix)
813	})
814}
815
816// ResolveIdentityImmutableMetadata retrieve an Identity that has the exact given metadata on
817// one of it's version. If multiple version have the same key, the first defined take precedence.
818func (c *RepoCache) ResolveIdentityImmutableMetadata(key string, value string) (*IdentityCache, error) {
819	return c.ResolveIdentityMatcher(func(excerpt *IdentityExcerpt) bool {
820		return excerpt.ImmutableMetadata[key] == value
821	})
822}
823
824func (c *RepoCache) ResolveIdentityExcerptMatcher(f func(*IdentityExcerpt) bool) (*IdentityExcerpt, error) {
825	id, err := c.resolveIdentityMatcher(f)
826	if err != nil {
827		return nil, err
828	}
829	return c.ResolveIdentityExcerpt(id)
830}
831
832func (c *RepoCache) ResolveIdentityMatcher(f func(*IdentityExcerpt) bool) (*IdentityCache, error) {
833	id, err := c.resolveIdentityMatcher(f)
834	if err != nil {
835		return nil, err
836	}
837	return c.ResolveIdentity(id)
838}
839
840func (c *RepoCache) resolveIdentityMatcher(f func(*IdentityExcerpt) bool) (entity.Id, error) {
841	// preallocate but empty
842	matching := make([]entity.Id, 0, 5)
843
844	for _, excerpt := range c.identitiesExcerpts {
845		if f(excerpt) {
846			matching = append(matching, excerpt.Id)
847		}
848	}
849
850	if len(matching) > 1 {
851		return entity.UnsetId, identity.NewErrMultipleMatch(matching)
852	}
853
854	if len(matching) == 0 {
855		return entity.UnsetId, identity.ErrIdentityNotExist
856	}
857
858	return matching[0], nil
859}
860
861// AllIdentityIds return all known identity ids
862func (c *RepoCache) AllIdentityIds() []entity.Id {
863	result := make([]entity.Id, len(c.identitiesExcerpts))
864
865	i := 0
866	for _, excerpt := range c.identitiesExcerpts {
867		result[i] = excerpt.Id
868		i++
869	}
870
871	return result
872}
873
874func (c *RepoCache) SetUserIdentity(i *IdentityCache) error {
875	err := identity.SetUserIdentity(c.repo, i.Identity)
876	if err != nil {
877		return err
878	}
879
880	// Make sure that everything is fine
881	if _, ok := c.identities[i.Id()]; !ok {
882		panic("SetUserIdentity while the identity is not from the cache, something is wrong")
883	}
884
885	c.userIdentityId = i.Id()
886
887	return nil
888}
889
890func (c *RepoCache) GetUserIdentity() (*IdentityCache, error) {
891	if c.userIdentityId != "" {
892		i, ok := c.identities[c.userIdentityId]
893		if ok {
894			return i, nil
895		}
896	}
897
898	i, err := identity.GetUserIdentity(c.repo)
899	if err != nil {
900		return nil, err
901	}
902
903	cached := NewIdentityCache(c, i)
904	c.identities[i.Id()] = cached
905	c.userIdentityId = i.Id()
906
907	return cached, nil
908}
909
910func (c *RepoCache) GetUserIdentityExcerpt() (*IdentityExcerpt, error) {
911	if c.userIdentityId == "" {
912		id, err := identity.GetUserIdentityId(c.repo)
913		if err != nil {
914			return nil, err
915		}
916		c.userIdentityId = id
917	}
918
919	excerpt, ok := c.identitiesExcerpts[c.userIdentityId]
920	if !ok {
921		return nil, fmt.Errorf("cache: missing identity excerpt %v", c.userIdentityId)
922	}
923	return excerpt, nil
924}
925
926func (c *RepoCache) IsUserIdentitySet() (bool, error) {
927	return identity.IsUserIdentitySet(c.repo)
928}
929
930func (c *RepoCache) NewIdentityFromGitUser() (*IdentityCache, error) {
931	return c.NewIdentityFromGitUserRaw(nil)
932}
933
934func (c *RepoCache) NewIdentityFromGitUserRaw(metadata map[string]string) (*IdentityCache, error) {
935	i, err := identity.NewFromGitUser(c.repo)
936	if err != nil {
937		return nil, err
938	}
939	return c.finishIdentity(i, metadata)
940}
941
942// NewIdentity create a new identity
943// The new identity is written in the repository (commit)
944func (c *RepoCache) NewIdentity(name string, email string) (*IdentityCache, error) {
945	return c.NewIdentityRaw(name, email, "", nil)
946}
947
948// NewIdentityFull create a new identity
949// The new identity is written in the repository (commit)
950func (c *RepoCache) NewIdentityFull(name string, email string, avatarUrl string) (*IdentityCache, error) {
951	return c.NewIdentityRaw(name, email, avatarUrl, nil)
952}
953
954func (c *RepoCache) NewIdentityRaw(name string, email string, avatarUrl string, metadata map[string]string) (*IdentityCache, error) {
955	i := identity.NewIdentityFull(name, email, avatarUrl)
956	return c.finishIdentity(i, metadata)
957}
958
959func (c *RepoCache) finishIdentity(i *identity.Identity, metadata map[string]string) (*IdentityCache, error) {
960	for key, value := range metadata {
961		i.SetMetadata(key, value)
962	}
963
964	err := i.Commit(c.repo)
965	if err != nil {
966		return nil, err
967	}
968
969	if _, has := c.identities[i.Id()]; has {
970		return nil, fmt.Errorf("identity %s already exist in the cache", i.Id())
971	}
972
973	cached := NewIdentityCache(c, i)
974	c.identities[i.Id()] = cached
975
976	// force the write of the excerpt
977	err = c.identityUpdated(i.Id())
978	if err != nil {
979		return nil, err
980	}
981
982	return cached, nil
983}