2 files changed, 67 insertions, 9 deletions

diff --git a/storage/transactional/storage.go b/storage/transactional/storage.go
index fbb3d35..b81b104 100644
--- a/storage/transactional/storage.go
+++ b/storage/transactional/storage.go
@@ -1,6 +1,9 @@
 package transactional
 
 import (
+	"io"
+
+	"gopkg.in/src-d/go-git.v4/plumbing/storer"
 	"gopkg.in/src-d/go-git.v4/storage"
 )
 
@@ -10,7 +13,13 @@ import (
 //
 // The API and functionality of this package are considered EXPERIMENTAL and is
 // not considered stable nor production ready.
-type Storage struct {
+type Storage interface {
+	storage.Storer
+	Commit() error
+}
+
+// basic implements the Storage interface.
+type basic struct {
 	s, temporal storage.Storer
 
 	*ObjectStorage
@@ -20,11 +29,18 @@ type Storage struct {
 	*ConfigStorage
 }
 
+// packageWriter implements storer.PackfileWriter interface over
+// a Storage with a temporal storer that supports it.
+type packageWriter struct {
+	*basic
+	pw storer.PackfileWriter
+}
+
 // NewStorage returns a new Storage based on two repositories, base is the base
-// repository where the read operations are read and temportal is were all
+// repository where the read operations are read and temporal is were all
 // the write operations are stored.
-func NewStorage(base, temporal storage.Storer) *Storage {
-	return &Storage{
+func NewStorage(base, temporal storage.Storer) Storage {
+	st := &basic{
 		s:        base,
 		temporal: temporal,
 
@@ -34,10 +50,20 @@ func NewStorage(base, temporal storage.Storer) *Storage {
 		ShallowStorage:   NewShallowStorage(base, temporal),
 		ConfigStorage:    NewConfigStorage(base, temporal),
 	}
+
+	pw, ok := temporal.(storer.PackfileWriter)
+	if ok {
+		return &packageWriter{
+			basic: st,
+			pw:    pw,
+		}
+	}
+
+	return st
 }
 
 // Module it honors the storage.ModuleStorer interface.
-func (s *Storage) Module(name string) (storage.Storer, error) {
+func (s *basic) Module(name string) (storage.Storer, error) {
 	base, err := s.s.Module(name)
 	if err != nil {
 		return nil, err
@@ -52,7 +78,7 @@ func (s *Storage) Module(name string) (storage.Storer, error) {
 }
 
 // Commit it copies the content of the temporal storage into the base storage.
-func (s *Storage) Commit() error {
+func (s *basic) Commit() error {
 	for _, c := range []interface{ Commit() error }{
 		s.ObjectStorage,
 		s.ReferenceStorage,
@@ -67,3 +93,8 @@ func (s *Storage) Commit() error {
 
 	return nil
 }
+
+// PackfileWriter honors storage.PackfileWriter.
+func (s *packageWriter) PackfileWriter() (io.WriteCloser, error) {
+	return s.pw.PackfileWriter()
+}
diff --git a/storage/transactional/storage_test.go b/storage/transactional/storage_test.go
index 6aaea0d..63ebfb1 100644
--- a/storage/transactional/storage_test.go
+++ b/storage/transactional/storage_test.go
@@ -4,7 +4,12 @@ import (
 	"testing"
 
 	. "gopkg.in/check.v1"
+	"gopkg.in/src-d/go-billy.v4/memfs"
 	"gopkg.in/src-d/go-git.v4/plumbing"
+	"gopkg.in/src-d/go-git.v4/plumbing/cache"
+	"gopkg.in/src-d/go-git.v4/plumbing/storer"
+	"gopkg.in/src-d/go-git.v4/storage"
+	"gopkg.in/src-d/go-git.v4/storage/filesystem"
 	"gopkg.in/src-d/go-git.v4/storage/memory"
 	"gopkg.in/src-d/go-git.v4/storage/test"
 )
@@ -13,13 +18,25 @@ func Test(t *testing.T) { TestingT(t) }
 
 type StorageSuite struct {
 	test.BaseStorageSuite
+	temporal func() storage.Storer
 }
 
-var _ = Suite(&StorageSuite{})
+var _ = Suite(&StorageSuite{
+	temporal: func() storage.Storer {
+		return memory.NewStorage()
+	},
+})
+
+var _ = Suite(&StorageSuite{
+	temporal: func() storage.Storer {
+		fs := memfs.New()
+		return filesystem.NewStorage(fs, cache.NewObjectLRUDefault())
+	},
+})
 
 func (s *StorageSuite) SetUpTest(c *C) {
 	base := memory.NewStorage()
-	temporal := memory.NewStorage()
+	temporal := s.temporal()
 
 	s.BaseStorageSuite = test.NewBaseStorageSuite(NewStorage(base, temporal))
 	s.BaseStorageSuite.SetUpTest(c)
@@ -27,7 +44,7 @@ func (s *StorageSuite) SetUpTest(c *C) {
 
 func (s *StorageSuite) TestCommit(c *C) {
 	base := memory.NewStorage()
-	temporal := memory.NewStorage()
+	temporal := s.temporal()
 	st := NewStorage(base, temporal)
 
 	commit := base.NewEncodedObject()
@@ -50,3 +67,13 @@ func (s *StorageSuite) TestCommit(c *C) {
 	c.Assert(err, IsNil)
 	c.Assert(obj.Hash(), Equals, commit.Hash())
 }
+
+func (s *StorageSuite) TestTransactionalPackfileWriter(c *C) {
+	base := memory.NewStorage()
+	temporal := s.temporal()
+	st := NewStorage(base, temporal)
+
+	_, tmpOK := temporal.(storer.PackfileWriter)
+	_, ok := st.(storer.PackfileWriter)
+	c.Assert(ok, Equals, tmpOK)
+}