cache: add proper locking to avoid concurrent access

3 files changed, 123 insertions, 31 deletions

diff --git a/cache/filter.go b/cache/filter.go
index 9b1de1d5..f840067b 100644
--- a/cache/filter.go
+++ b/cache/filter.go
@@ -4,10 +4,17 @@ import (
 	"strings"
 
 	"github.com/MichaelMure/git-bug/bug"
+	"github.com/MichaelMure/git-bug/entity"
 )
 
+// resolver has the resolving functions needed by filters.
+// This exist mainly to go through the functions of the cache with proper locking.
+type resolver interface {
+	ResolveIdentityExcerpt(id entity.Id) (*IdentityExcerpt, error)
+}
+
 // Filter is a predicate that match a subset of bugs
-type Filter func(repoCache *RepoCache, excerpt *BugExcerpt) bool
+type Filter func(excerpt *BugExcerpt, resolver resolver) bool
 
 // StatusFilter return a Filter that match a bug status
 func StatusFilter(query string) (Filter, error) {
@@ -16,21 +23,21 @@ func StatusFilter(query string) (Filter, error) {
 		return nil, err
 	}
 
-	return func(repoCache *RepoCache, excerpt *BugExcerpt) bool {
+	return func(excerpt *BugExcerpt, resolver resolver) bool {
 		return excerpt.Status == status
 	}, nil
 }
 
 // AuthorFilter return a Filter that match a bug author
 func AuthorFilter(query string) Filter {
-	return func(repoCache *RepoCache, excerpt *BugExcerpt) bool {
+	return func(excerpt *BugExcerpt, resolver resolver) bool {
 		query = strings.ToLower(query)
 
 		// Normal identity
 		if excerpt.AuthorId != "" {
-			author, ok := repoCache.identitiesExcerpts[excerpt.AuthorId]
-			if !ok {
-				panic("missing identity in the cache")
+			author, err := resolver.ResolveIdentityExcerpt(excerpt.AuthorId)
+			if err != nil {
+				panic(err)
 			}
 
 			return author.Match(query)
@@ -43,7 +50,7 @@ func AuthorFilter(query string) Filter {
 
 // LabelFilter return a Filter that match a label
 func LabelFilter(label string) Filter {
-	return func(repoCache *RepoCache, excerpt *BugExcerpt) bool {
+	return func(excerpt *BugExcerpt, resolver resolver) bool {
 		for _, l := range excerpt.Labels {
 			if string(l) == label {
 				return true
@@ -55,13 +62,13 @@ func LabelFilter(label string) Filter {
 
 // ActorFilter return a Filter that match a bug actor
 func ActorFilter(query string) Filter {
-	return func(repoCache *RepoCache, excerpt *BugExcerpt) bool {
+	return func(excerpt *BugExcerpt, resolver resolver) bool {
 		query = strings.ToLower(query)
 
 		for _, id := range excerpt.Actors {
-			identityExcerpt, ok := repoCache.identitiesExcerpts[id]
-			if !ok {
-				panic("missing identity in the cache")
+			identityExcerpt, err := resolver.ResolveIdentityExcerpt(id)
+			if err != nil {
+				panic(err)
 			}
 
 			if identityExcerpt.Match(query) {
@@ -74,13 +81,13 @@ func ActorFilter(query string) Filter {
 
 // ParticipantFilter return a Filter that match a bug participant
 func ParticipantFilter(query string) Filter {
-	return func(repoCache *RepoCache, excerpt *BugExcerpt) bool {
+	return func(excerpt *BugExcerpt, resolver resolver) bool {
 		query = strings.ToLower(query)
 
 		for _, id := range excerpt.Participants {
-			identityExcerpt, ok := repoCache.identitiesExcerpts[id]
-			if !ok {
-				panic("missing identity in the cache")
+			identityExcerpt, err := resolver.ResolveIdentityExcerpt(id)
+			if err != nil {
+				panic(err)
 			}
 
 			if identityExcerpt.Match(query) {
@@ -93,7 +100,7 @@ func ParticipantFilter(query string) Filter {
 
 // TitleFilter return a Filter that match if the title contains the given query
 func TitleFilter(query string) Filter {
-	return func(repo *RepoCache, excerpt *BugExcerpt) bool {
+	return func(excerpt *BugExcerpt, resolver resolver) bool {
 		return strings.Contains(
 			strings.ToLower(excerpt.Title),
 			strings.ToLower(query),
@@ -103,7 +110,7 @@ func TitleFilter(query string) Filter {
 
 // NoLabelFilter return a Filter that match the absence of labels
 func NoLabelFilter() Filter {
-	return func(repoCache *RepoCache, excerpt *BugExcerpt) bool {
+	return func(excerpt *BugExcerpt, resolver resolver) bool {
 		return len(excerpt.Labels) == 0
 	}
 }
@@ -120,32 +127,32 @@ type Filters struct {
 }
 
 // Match check if a bug match the set of filters
-func (f *Filters) Match(repoCache *RepoCache, excerpt *BugExcerpt) bool {
-	if match := f.orMatch(f.Status, repoCache, excerpt); !match {
+func (f *Filters) Match(excerpt *BugExcerpt, resolver resolver) bool {
+	if match := f.orMatch(f.Status, excerpt, resolver); !match {
 		return false
 	}
 
-	if match := f.orMatch(f.Author, repoCache, excerpt); !match {
+	if match := f.orMatch(f.Author, excerpt, resolver); !match {
 		return false
 	}
 
-	if match := f.orMatch(f.Participant, repoCache, excerpt); !match {
+	if match := f.orMatch(f.Participant, excerpt, resolver); !match {
 		return false
 	}
 
-	if match := f.orMatch(f.Actor, repoCache, excerpt); !match {
+	if match := f.orMatch(f.Actor, excerpt, resolver); !match {
 		return false
 	}
 
-	if match := f.andMatch(f.Label, repoCache, excerpt); !match {
+	if match := f.andMatch(f.Label, excerpt, resolver); !match {
 		return false
 	}
 
-	if match := f.andMatch(f.NoFilters, repoCache, excerpt); !match {
+	if match := f.andMatch(f.NoFilters, excerpt, resolver); !match {
 		return false
 	}
 
-	if match := f.andMatch(f.Title, repoCache, excerpt); !match {
+	if match := f.andMatch(f.Title, excerpt, resolver); !match {
 		return false
 	}
 
@@ -153,28 +160,28 @@ func (f *Filters) Match(repoCache *RepoCache, excerpt *BugExcerpt) bool {
 }
 
 // Check if any of the filters provided match the bug
-func (*Filters) orMatch(filters []Filter, repoCache *RepoCache, excerpt *BugExcerpt) bool {
+func (*Filters) orMatch(filters []Filter, excerpt *BugExcerpt, resolver resolver) bool {
 	if len(filters) == 0 {
 		return true
 	}
 
 	match := false
 	for _, f := range filters {
-		match = match || f(repoCache, excerpt)
+		match = match || f(excerpt, resolver)
 	}
 
 	return match
 }
 
 // Check if all of the filters provided match the bug
-func (*Filters) andMatch(filters []Filter, repoCache *RepoCache, excerpt *BugExcerpt) bool {
+func (*Filters) andMatch(filters []Filter, excerpt *BugExcerpt, resolver resolver) bool {
 	if len(filters) == 0 {
 		return true
 	}
 
 	match := true
 	for _, f := range filters {
-		match = match && f(repoCache, excerpt)
+		match = match && f(excerpt, resolver)
 	}
 
 	return match
diff --git a/cache/filter_test.go b/cache/filter_test.go
index a47d2ad7..2c7fabc0 100644
--- a/cache/filter_test.go
+++ b/cache/filter_test.go
@@ -28,7 +28,7 @@ func TestTitleFilter(t *testing.T) {
 		t.Run(tt.name, func(t *testing.T) {
 			filter := TitleFilter(tt.query)
 			excerpt := &BugExcerpt{Title: tt.title}
-			assert.Equal(t, tt.match, filter(nil, excerpt))
+			assert.Equal(t, tt.match, filter(excerpt, nil))
 		})
 	}
 }
diff --git a/cache/repo_cache.go b/cache/repo_cache.go
index 442a7c8b..c8d6bd69 100644
--- a/cache/repo_cache.go
+++ b/cache/repo_cache.go
@@ -10,6 +10,7 @@ import (
 	"path"
 	"sort"
 	"strconv"
+	"sync"
 	"time"
 
 	"github.com/pkg/errors"
@@ -57,11 +58,13 @@ type RepoCache struct {
 	// the underlying repo
 	repo repository.ClockedRepo
 
+	muBug sync.RWMutex
 	// excerpt of bugs data for all bugs
 	bugExcerpts map[entity.Id]*BugExcerpt
 	// bug loaded in memory
 	bugs map[entity.Id]*BugCache
 
+	muIdentity sync.RWMutex
 	// excerpt of identities data for all identities
 	identitiesExcerpts map[entity.Id]*IdentityExcerpt
 	// identities loaded in memory
@@ -157,6 +160,11 @@ func (c *RepoCache) lock() error {
 }
 
 func (c *RepoCache) Close() error {
+	c.muBug.Lock()
+	defer c.muBug.Unlock()
+	c.muIdentity.Lock()
+	defer c.muIdentity.Unlock()
+
 	c.identities = make(map[entity.Id]*IdentityCache)
 	c.identitiesExcerpts = nil
 	c.bugs = make(map[entity.Id]*BugCache)
@@ -169,12 +177,16 @@ func (c *RepoCache) Close() error {
 // bugUpdated is a callback to trigger when the excerpt of a bug changed,
 // that is each time a bug is updated
 func (c *RepoCache) bugUpdated(id entity.Id) error {
+	c.muBug.Lock()
+
 	b, ok := c.bugs[id]
 	if !ok {
+		c.muBug.Unlock()
 		panic("missing bug in the cache")
 	}
 
 	c.bugExcerpts[id] = NewBugExcerpt(b.bug, b.Snapshot())
+	c.muBug.Unlock()
 
 	// we only need to write the bug cache
 	return c.writeBugCache()
@@ -183,12 +195,16 @@ func (c *RepoCache) bugUpdated(id entity.Id) error {
 // identityUpdated is a callback to trigger when the excerpt of an identity
 // changed, that is each time an identity is updated
 func (c *RepoCache) identityUpdated(id entity.Id) error {
+	c.muIdentity.Lock()
+
 	i, ok := c.identities[id]
 	if !ok {
+		c.muIdentity.Unlock()
 		panic("missing identity in the cache")
 	}
 
 	c.identitiesExcerpts[id] = NewIdentityExcerpt(i.Identity)
+	c.muIdentity.Unlock()
 
 	// we only need to write the identity cache
 	return c.writeIdentityCache()
@@ -205,6 +221,9 @@ func (c *RepoCache) load() error {
 
 // load will try to read from the disk the bug cache file
 func (c *RepoCache) loadBugCache() error {
+	c.muBug.Lock()
+	defer c.muBug.Unlock()
+
 	f, err := os.Open(bugCacheFilePath(c.repo))
 	if err != nil {
 		return err
@@ -234,6 +253,9 @@ func (c *RepoCache) loadBugCache() error {
 
 // load will try to read from the disk the identity cache file
 func (c *RepoCache) loadIdentityCache() error {
+	c.muIdentity.Lock()
+	defer c.muIdentity.Unlock()
+
 	f, err := os.Open(identityCacheFilePath(c.repo))
 	if err != nil {
 		return err
@@ -272,6 +294,9 @@ func (c *RepoCache) write() error {
 
 // write will serialize on disk the bug cache file
 func (c *RepoCache) writeBugCache() error {
+	c.muBug.RLock()
+	defer c.muBug.RUnlock()
+
 	var data bytes.Buffer
 
 	aux := struct {
@@ -304,6 +329,9 @@ func (c *RepoCache) writeBugCache() error {
 
 // write will serialize on disk the identity cache file
 func (c *RepoCache) writeIdentityCache() error {
+	c.muIdentity.RLock()
+	defer c.muIdentity.RUnlock()
+
 	var data bytes.Buffer
 
 	aux := struct {
@@ -343,6 +371,11 @@ func identityCacheFilePath(repo repository.Repo) string {
 }
 
 func (c *RepoCache) buildCache() error {
+	c.muBug.Lock()
+	defer c.muBug.Unlock()
+	c.muIdentity.Lock()
+	defer c.muIdentity.Unlock()
+
 	_, _ = fmt.Fprintf(os.Stderr, "Building identity cache... ")
 
 	c.identitiesExcerpts = make(map[entity.Id]*IdentityExcerpt)
@@ -380,6 +413,9 @@ func (c *RepoCache) buildCache() error {
 
 // ResolveBugExcerpt retrieve a BugExcerpt matching the exact given id
 func (c *RepoCache) ResolveBugExcerpt(id entity.Id) (*BugExcerpt, error) {
+	c.muBug.RLock()
+	defer c.muBug.RUnlock()
+
 	e, ok := c.bugExcerpts[id]
 	if !ok {
 		return nil, bug.ErrBugNotExist
@@ -390,7 +426,9 @@ func (c *RepoCache) ResolveBugExcerpt(id entity.Id) (*BugExcerpt, error) {
 
 // ResolveBug retrieve a bug matching the exact given id
 func (c *RepoCache) ResolveBug(id entity.Id) (*BugCache, error) {
+	c.muBug.RLock()
 	cached, ok := c.bugs[id]
+	c.muBug.RUnlock()
 	if ok {
 		return cached, nil
 	}
@@ -401,7 +439,10 @@ func (c *RepoCache) ResolveBug(id entity.Id) (*BugCache, error) {
 	}
 
 	cached = NewBugCache(c, b)
+
+	c.muBug.Lock()
 	c.bugs[id] = cached
+	c.muBug.Unlock()
 
 	return cached, nil
 }
@@ -448,6 +489,9 @@ func (c *RepoCache) ResolveBugMatcher(f func(*BugExcerpt) bool) (*BugCache, erro
 }
 
 func (c *RepoCache) resolveBugMatcher(f func(*BugExcerpt) bool) (entity.Id, error) {
+	c.muBug.RLock()
+	defer c.muBug.RUnlock()
+
 	// preallocate but empty
 	matching := make([]entity.Id, 0, 5)
 
@@ -470,6 +514,9 @@ func (c *RepoCache) resolveBugMatcher(f func(*BugExcerpt) bool) (entity.Id, erro
 
 // QueryBugs return the id of all Bug matching the given Query
 func (c *RepoCache) QueryBugs(query *Query) []entity.Id {
+	c.muBug.RLock()
+	defer c.muBug.RUnlock()
+
 	if query == nil {
 		return c.AllBugsIds()
 	}
@@ -477,7 +524,7 @@ func (c *RepoCache) QueryBugs(query *Query) []entity.Id {
 	var filtered []*BugExcerpt
 
 	for _, excerpt := range c.bugExcerpts {
-		if query.Match(c, excerpt) {
+		if query.Match(excerpt, c) {
 			filtered = append(filtered, excerpt)
 		}
 	}
@@ -512,6 +559,9 @@ func (c *RepoCache) QueryBugs(query *Query) []entity.Id {
 
 // AllBugsIds return all known bug ids
 func (c *RepoCache) AllBugsIds() []entity.Id {
+	c.muBug.RLock()
+	defer c.muBug.RUnlock()
+
 	result := make([]entity.Id, len(c.bugExcerpts))
 
 	i := 0
@@ -529,6 +579,9 @@ func (c *RepoCache) AllBugsIds() []entity.Id {
 // labels are defined in a configuration file. Until that, the default behavior
 // is to return the list of labels already used.
 func (c *RepoCache) ValidLabels() []bug.Label {
+	c.muBug.RLock()
+	defer c.muBug.RUnlock()
+
 	set := map[bug.Label]interface{}{}
 
 	for _, excerpt := range c.bugExcerpts {
@@ -588,12 +641,15 @@ func (c *RepoCache) NewBugRaw(author *IdentityCache, unixTime int64, title strin
 		return nil, nil, err
 	}
 
+	c.muBug.Lock()
 	if _, has := c.bugs[b.Id()]; has {
+		c.muBug.Unlock()
 		return nil, nil, fmt.Errorf("bug %s already exist in the cache", b.Id())
 	}
 
 	cached := NewBugCache(c, b)
 	c.bugs[b.Id()] = cached
+	c.muBug.Unlock()
 
 	// force the write of the excerpt
 	err = c.bugUpdated(b.Id())
@@ -639,7 +695,9 @@ func (c *RepoCache) MergeAll(remote string) <-chan entity.MergeResult {
 			switch result.Status {
 			case entity.MergeStatusNew, entity.MergeStatusUpdated:
 				i := result.Entity.(*identity.Identity)
+				c.muIdentity.Lock()
 				c.identitiesExcerpts[result.Id] = NewIdentityExcerpt(i)
+				c.muIdentity.Unlock()
 			}
 		}
 
@@ -655,7 +713,9 @@ func (c *RepoCache) MergeAll(remote string) <-chan entity.MergeResult {
 			case entity.MergeStatusNew, entity.MergeStatusUpdated:
 				b := result.Entity.(*bug.Bug)
 				snap := b.Compile()
+				c.muBug.Lock()
 				c.bugExcerpts[result.Id] = NewBugExcerpt(b, &snap)
+				c.muBug.Unlock()
 			}
 		}
 
@@ -771,6 +831,9 @@ func repoIsAvailable(repo repository.Repo) error {
 
 // ResolveIdentityExcerpt retrieve a IdentityExcerpt matching the exact given id
 func (c *RepoCache) ResolveIdentityExcerpt(id entity.Id) (*IdentityExcerpt, error) {
+	c.muIdentity.RLock()
+	defer c.muIdentity.RUnlock()
+
 	e, ok := c.identitiesExcerpts[id]
 	if !ok {
 		return nil, identity.ErrIdentityNotExist
@@ -781,7 +844,9 @@ func (c *RepoCache) ResolveIdentityExcerpt(id entity.Id) (*IdentityExcerpt, erro
 
 // ResolveIdentity retrieve an identity matching the exact given id
 func (c *RepoCache) ResolveIdentity(id entity.Id) (*IdentityCache, error) {
+	c.muIdentity.RLock()
 	cached, ok := c.identities[id]
+	c.muIdentity.RUnlock()
 	if ok {
 		return cached, nil
 	}
@@ -792,7 +857,10 @@ func (c *RepoCache) ResolveIdentity(id entity.Id) (*IdentityCache, error) {
 	}
 
 	cached = NewIdentityCache(c, i)
+
+	c.muIdentity.Lock()
 	c.identities[id] = cached
+	c.muIdentity.Unlock()
 
 	return cached, nil
 }
@@ -838,6 +906,9 @@ func (c *RepoCache) ResolveIdentityMatcher(f func(*IdentityExcerpt) bool) (*Iden
 }
 
 func (c *RepoCache) resolveIdentityMatcher(f func(*IdentityExcerpt) bool) (entity.Id, error) {
+	c.muIdentity.RLock()
+	defer c.muIdentity.RUnlock()
+
 	// preallocate but empty
 	matching := make([]entity.Id, 0, 5)
 
@@ -860,6 +931,9 @@ func (c *RepoCache) resolveIdentityMatcher(f func(*IdentityExcerpt) bool) (entit
 
 // AllIdentityIds return all known identity ids
 func (c *RepoCache) AllIdentityIds() []entity.Id {
+	c.muIdentity.RLock()
+	defer c.muIdentity.RUnlock()
+
 	result := make([]entity.Id, len(c.identitiesExcerpts))
 
 	i := 0
@@ -877,6 +951,9 @@ func (c *RepoCache) SetUserIdentity(i *IdentityCache) error {
 		return err
 	}
 
+	c.muIdentity.RLock()
+	defer c.muIdentity.RUnlock()
+
 	// Make sure that everything is fine
 	if _, ok := c.identities[i.Id()]; !ok {
 		panic("SetUserIdentity while the identity is not from the cache, something is wrong")
@@ -895,6 +972,9 @@ func (c *RepoCache) GetUserIdentity() (*IdentityCache, error) {
 		}
 	}
 
+	c.muIdentity.Lock()
+	defer c.muIdentity.Unlock()
+
 	i, err := identity.GetUserIdentity(c.repo)
 	if err != nil {
 		return nil, err
@@ -916,6 +996,9 @@ func (c *RepoCache) GetUserIdentityExcerpt() (*IdentityExcerpt, error) {
 		c.userIdentityId = id
 	}
 
+	c.muIdentity.RLock()
+	defer c.muIdentity.RUnlock()
+
 	excerpt, ok := c.identitiesExcerpts[c.userIdentityId]
 	if !ok {
 		return nil, fmt.Errorf("cache: missing identity excerpt %v", c.userIdentityId)
@@ -966,12 +1049,14 @@ func (c *RepoCache) finishIdentity(i *identity.Identity, metadata map[string]str
 		return nil, err
 	}
 
+	c.muIdentity.Lock()
 	if _, has := c.identities[i.Id()]; has {
 		return nil, fmt.Errorf("identity %s already exist in the cache", i.Id())
 	}
 
 	cached := NewIdentityCache(c, i)
 	c.identities[i.Id()] = cached
+	c.muIdentity.Unlock()
 
 	// force the write of the excerpt
 	err = c.identityUpdated(i.Id())