core: ObjectStorage.Begin and TxObjectStorage

2 files changed, 24 insertions, 16 deletions

diff --git a/formats/packfile/decoder.go b/formats/packfile/decoder.go
index 6d0cd8b..5b5763c 100644
--- a/formats/packfile/decoder.go
+++ b/formats/packfile/decoder.go
@@ -42,25 +42,33 @@ type Decoder struct {
 }
 
 // NewDecoder returns a new Decoder that reads from r.
-func NewDecoder(r ReadRecaller) *Decoder {
+func NewDecoder(r ReadRecaller, s core.ObjectStorage) *Decoder {
 	return &Decoder{
 		p: NewParser(r),
+		s: s,
 	}
 }
 
 // Decode reads a packfile and stores it in the value pointed to by s.
-func (d *Decoder) Decode(s core.ObjectStorage) error {
-	d.s = s
-
+func (d *Decoder) Decode() error {
 	count, err := d.p.ReadHeader()
 	if err != nil {
 		return err
 	}
 
-	return d.readObjects(count)
+	tx := d.s.Begin()
+	if err := d.readObjects(tx, count); err != nil {
+		if err := tx.Rollback(); err != nil {
+			return nil
+		}
+
+		return err
+	}
+
+	return tx.Commit()
 }
 
-func (d *Decoder) readObjects(count uint32) error {
+func (d *Decoder) readObjects(tx core.TxObjectStorage, count uint32) error {
 	// This code has 50-80 µs of overhead per object not counting zlib inflation.
 	// Together with zlib inflation, it's 400-410 µs for small objects.
 	// That's 1 sec for ~2450 objects, ~4.20 MB, or ~250 ms per MB,
@@ -85,7 +93,7 @@ func (d *Decoder) readObjects(count uint32) error {
 			return err
 		}
 
-		_, err = d.s.Set(obj)
+		_, err = tx.Set(obj)
 		if err == io.EOF {
 			break
 		}
diff --git a/formats/packfile/decoder_test.go b/formats/packfile/decoder_test.go
index fe25ee4..8c73b4e 100644
--- a/formats/packfile/decoder_test.go
+++ b/formats/packfile/decoder_test.go
@@ -28,10 +28,10 @@ func (s *ReaderSuite) TestReadPackfile(c *C) {
 	data, _ := base64.StdEncoding.DecodeString(packFileWithEmptyObjects)
 	f := bytes.NewReader(data)
 	r := NewStream(f)
-	d := NewDecoder(r)
-
 	sto := memory.NewStorage()
-	err := d.Decode(sto.ObjectStorage())
+	d := NewDecoder(r, sto.ObjectStorage())
+
+	err := d.Decode()
 	c.Assert(err, IsNil)
 
 	AssertObjects(c, sto, []string{
@@ -61,10 +61,10 @@ func (s *ReaderSuite) testReadPackfileGitFixture(c *C, file string, format Forma
 	f, err := os.Open(file)
 	c.Assert(err, IsNil)
 	r := NewSeekable(f)
-	d := NewDecoder(r)
-
 	sto := memory.NewStorage()
-	err = d.Decode(sto.ObjectStorage())
+	d := NewDecoder(r, sto.ObjectStorage())
+
+	err = d.Decode()
 	c.Assert(err, IsNil)
 
 	AssertObjects(c, sto, []string{
@@ -170,10 +170,10 @@ func readFromFile(c *C, file string, format Format) *memory.ObjectStorage {
 	f, err := os.Open(file)
 	c.Assert(err, IsNil)
 	r := NewSeekable(f)
-	d := NewDecoder(r)
-
 	sto := memory.NewStorage()
-	err = d.Decode(sto.ObjectStorage())
+	d := NewDecoder(r, sto.ObjectStorage())
+
+	err = d.Decode()
 	c.Assert(err, IsNil)
 
 	return sto.ObjectStorage().(*memory.ObjectStorage)