Merge pull request #563 from erizocosmico/perf/dotgit-ref-cache
dotgit: rewrite the way references are looked up
diff --git a/storage/filesystem/internal/dotgit/dotgit.go b/storage/filesystem/internal/dotgit/dotgit.go
index e2ff51b..b50cdab 100644
--- a/storage/filesystem/internal/dotgit/dotgit.go
+++ b/storage/filesystem/internal/dotgit/dotgit.go
@@ -8,6 +8,7 @@
stdioutil "io/ioutil"
"os"
"strings"
+ "time"
"gopkg.in/src-d/go-git.v4/plumbing"
"gopkg.in/src-d/go-git.v4/utils/ioutil"
@@ -56,14 +57,16 @@
// The DotGit type represents a local git repository on disk. This
// type is not zero-value-safe, use the New function to initialize it.
type DotGit struct {
- fs billy.Filesystem
+ fs billy.Filesystem
+ cachedPackedRefs refCache
+ packedRefsLastMod time.Time
}
// New returns a DotGit value ready to be used. The path argument must
// be the absolute path of a git repository directory (e.g.
// "/foo/bar/.git").
func New(fs billy.Filesystem) *DotGit {
- return &DotGit{fs: fs}
+ return &DotGit{fs: fs, cachedPackedRefs: make(refCache)}
}
// Initialize creates all the folder scaffolding.
@@ -285,15 +288,57 @@
return ref, nil
}
- refs, err := d.Refs()
+ return d.packedRef(name)
+}
+
+func (d *DotGit) syncPackedRefs() error {
+ fi, err := d.fs.Stat(packedRefsPath)
+ if os.IsNotExist(err) {
+ return nil
+ }
+
if err != nil {
+ return err
+ }
+
+ if d.packedRefsLastMod.Before(fi.ModTime()) {
+ d.cachedPackedRefs = make(refCache)
+ f, err := d.fs.Open(packedRefsPath)
+ if err != nil {
+ if os.IsNotExist(err) {
+ return nil
+ }
+ return err
+ }
+ defer ioutil.CheckClose(f, &err)
+
+ s := bufio.NewScanner(f)
+ for s.Scan() {
+ ref, err := d.processLine(s.Text())
+ if err != nil {
+ return err
+ }
+
+ if ref != nil {
+ d.cachedPackedRefs[ref.Name()] = ref
+ }
+ }
+
+ d.packedRefsLastMod = fi.ModTime()
+
+ return s.Err()
+ }
+
+ return nil
+}
+
+func (d *DotGit) packedRef(name plumbing.ReferenceName) (*plumbing.Reference, error) {
+ if err := d.syncPackedRefs(); err != nil {
return nil, err
}
- for _, ref := range refs {
- if ref.Name() == name {
- return ref, nil
- }
+ if ref, ok := d.cachedPackedRefs[name]; ok {
+ return ref, nil
}
return nil, plumbing.ErrReferenceNotFound
@@ -315,28 +360,15 @@
}
func (d *DotGit) addRefsFromPackedRefs(refs *[]*plumbing.Reference) (err error) {
- f, err := d.fs.Open(packedRefsPath)
- if err != nil {
- if os.IsNotExist(err) {
- return nil
- }
+ if err := d.syncPackedRefs(); err != nil {
return err
}
- defer ioutil.CheckClose(f, &err)
- s := bufio.NewScanner(f)
- for s.Scan() {
- ref, err := d.processLine(s.Text())
- if err != nil {
- return err
- }
-
- if ref != nil {
- *refs = append(*refs, ref)
- }
+ for _, ref := range d.cachedPackedRefs {
+ *refs = append(*refs, ref)
}
- return s.Err()
+ return nil
}
func (d *DotGit) rewritePackedRefsWithoutRef(name plumbing.ReferenceName) (err error) {
@@ -511,3 +543,5 @@
func isHexAlpha(b byte) bool {
return b >= 'a' && b <= 'f' || b >= 'A' && b <= 'F'
}
+
+type refCache map[plumbing.ReferenceName]*plumbing.Reference
diff --git a/storage/filesystem/internal/dotgit/dotgit_test.go b/storage/filesystem/internal/dotgit/dotgit_test.go
index d935ec5..a7f16f4 100644
--- a/storage/filesystem/internal/dotgit/dotgit_test.go
+++ b/storage/filesystem/internal/dotgit/dotgit_test.go
@@ -134,6 +134,24 @@
}
+func BenchmarkRefMultipleTimes(b *testing.B) {
+ fs := fixtures.Basic().ByTag(".git").One().DotGit()
+ refname := plumbing.ReferenceName("refs/remotes/origin/branch")
+
+ dir := New(fs)
+ _, err := dir.Ref(refname)
+ if err != nil {
+ b.Fatalf("unexpected error: %s", err)
+ }
+
+ for i := 0; i < b.N; i++ {
+ _, err := dir.Ref(refname)
+ if err != nil {
+ b.Fatalf("unexpected error: %s", err)
+ }
+ }
+}
+
func (s *SuiteDotGit) TestRemoveRefFromReferenceFile(c *C) {
fs := fixtures.Basic().ByTag(".git").One().DotGit()
dir := New(fs)
