storage: IndexStorer implementation

4 files changed, 55 insertions, 1 deletions

diff --git a/common.go b/common.go
index ef1db3b..580a829 100644
--- a/common.go
+++ b/common.go
@@ -15,6 +15,7 @@ type Storer interface {
 	storer.EncodedObjectStorer
 	storer.ReferenceStorer
 	storer.ShallowStorer
+	storer.IndexStorer
 	config.ConfigStorer
 }
 
diff --git a/storage/filesystem/index.go b/storage/filesystem/index.go
new file mode 100644
index 0000000..456ef0b
--- /dev/null
+++ b/storage/filesystem/index.go
@@ -0,0 +1,44 @@
+package filesystem
+
+import (
+	"os"
+
+	"gopkg.in/src-d/go-git.v4/plumbing/format/index"
+	"gopkg.in/src-d/go-git.v4/storage/filesystem/internal/dotgit"
+)
+
+type IndexStorage struct {
+	dir *dotgit.DotGit
+}
+
+func (s *IndexStorage) SetIndex(idx *index.Index) error {
+	f, err := s.dir.IndexWriter()
+	if err != nil {
+		return err
+	}
+
+	defer f.Close()
+
+	e := index.NewEncoder(f)
+	return e.Encode(idx)
+}
+
+func (s *IndexStorage) Index() (*index.Index, error) {
+	idx := &index.Index{
+		Version: 2,
+	}
+
+	f, err := s.dir.Index()
+	if err != nil {
+		if os.IsNotExist(err) {
+			return idx, nil
+		}
+
+		return nil, err
+	}
+
+	defer f.Close()
+
+	d := index.NewDecoder(f)
+	return idx, d.Decode(idx)
+}
diff --git a/storage/memory/storage.go b/storage/memory/storage.go
index 444f289..5d0bff1 100644
--- a/storage/memory/storage.go
+++ b/storage/memory/storage.go
@@ -72,7 +72,7 @@ func (c *IndexStorage) SetIndex(idx *index.Index) error {
 
 func (c *IndexStorage) Index() (*index.Index, error) {
 	if c.index == nil {
-		c.index = &index.Index{}
+		c.index = &index.Index{Version: 2}
 	}
 
 	return c.index, nil
diff --git a/storage/test/storage_suite.go b/storage/test/storage_suite.go
index 088edce..ca2f783 100644
--- a/storage/test/storage_suite.go
+++ b/storage/test/storage_suite.go
@@ -297,6 +297,15 @@ func (s *BaseStorageSuite) TestSetConfigAndConfig(c *C) {
 	c.Assert(cfg, DeepEquals, expected)
 }
 
+func (s *BaseStorageSuite) TestIndex(c *C) {
+	expected := &index.Index{}
+	expected.Version = 2
+
+	idx, err := s.Storer.Index()
+	c.Assert(err, IsNil)
+	c.Assert(idx, DeepEquals, expected)
+}
+
 func (s *BaseStorageSuite) TestSetIndexAndIndex(c *C) {
 	expected := &index.Index{}
 	expected.Version = 2