Merge pull request #722 from AriehSchneier/populate-index

storage: filesystem, Populate index before use. Fixes #148

storage/filesystem/object.go

@@ -537,14 +537,21 @@ func (s *ObjectStorage) findObjectInPackfile(h plumbing.Hash) (plumbing.Hash, pl
 	return plumbing.ZeroHash, plumbing.ZeroHash, -1
 }
 
+// HashesWithPrefix returns all objects with a hash that starts with a prefix by searching for
+// them in the packfile and the git object directories.
 func (s *ObjectStorage) HashesWithPrefix(prefix []byte) ([]plumbing.Hash, error) {
 	hashes, err := s.dir.ObjectsWithPrefix(prefix)
 	if err != nil {
 		return nil, err
 	}
 
+	seen := hashListAsMap(hashes)
+
 	// TODO: This could be faster with some idxfile changes,
 	// or diving into the packfile.
+	if err := s.requireIndex(); err != nil {
+		return nil, err
+	}
 	for _, index := range s.index {
 		ei, err := index.Entries()
 		if err != nil {
@@ -558,6 +565,9 @@ func (s *ObjectStorage) HashesWithPrefix(prefix []byte) ([]plumbing.Hash, error)
 				return nil, err
 			}
 			if bytes.HasPrefix(e.Hash[:], prefix) {
+				if _, ok := seen[e.Hash]; ok {
+					continue
+				}
 				hashes = append(hashes, e.Hash)
 			}
 		}

storage/filesystem/object_test.go

@@ -406,6 +406,21 @@ func (s *FsSuite) TestHashesWithPrefix(c *C) {
 	c.Assert(hashes[0].String(), Equals, "f3dfe29d268303fc6e1bbce268605fc99573406e")
 }
 
+func (s *FsSuite) TestHashesWithPrefixFromPackfile(c *C) {
+	// Same setup as TestGetFromPackfile
+	fixtures.Basic().ByTag(".git").Test(c, func(f *fixtures.Fixture) {
+		fs := f.DotGit()
+		o := NewObjectStorage(dotgit.New(fs), cache.NewObjectLRUDefault())
+
+		expected := plumbing.NewHash("6ecf0ef2c2dffb796033e5a02219af86ec6584e5")
+		// Only pass the first 8 bytes
+		hashes, err := o.HashesWithPrefix(expected[:8])
+		c.Assert(err, IsNil)
+		c.Assert(hashes, HasLen, 1)
+		c.Assert(hashes[0], Equals, expected)
+	})
+}
+
 func BenchmarkPackfileIter(b *testing.B) {
 	defer fixtures.Clean()