server: add git server implementation (#190)

* server: add generic server implementation (transport-independent),
  both for git-upload-pack and git-receive-pack.
* server: move internal functions to internal/common.
* cli: add git-receive-pack and git-upload-pack implementations.
* format/packfile: add UpdateObjectStorage function, extracted from
  Remote.
* transport: implement tranport RPC-like, only with git-upload-pack and
  git-receive-pack methods. Client renamed to Transport.
* storer: add storer.Storer interface.
* protocol/packp: add UploadPackResponse constructor with packfile.
* protocol/packp: fix UploadPackResponse encoding, add tests.
* protocol/packp/capability: implement All.

1 files changed, 30 insertions, 0 deletions

diff --git a/plumbing/format/packfile/common.go b/plumbing/format/packfile/common.go
index 1656551..7da2b33 100644
--- a/plumbing/format/packfile/common.go
+++ b/plumbing/format/packfile/common.go
@@ -1,5 +1,11 @@
 package packfile
 
+import (
+	"io"
+
+	"gopkg.in/src-d/go-git.v4/plumbing/storer"
+)
+
 var signature = []byte{'P', 'A', 'C', 'K'}
 
 const (
@@ -13,3 +19,27 @@ const (
 	maskLength      = uint8(127) // 0111 1111
 	maskType        = uint8(112) // 0111 0000
 )
+
+// UpdateObjectStorage updates the given ObjectStorer with the contents of the
+// packfile.
+func UpdateObjectStorage(s storer.EncodedObjectStorer, packfile io.Reader) error {
+	if sw, ok := s.(storer.PackfileWriter); ok {
+		w, err := sw.PackfileWriter()
+		if err != nil {
+			return err
+		}
+
+		defer w.Close()
+		_, err = io.Copy(w, packfile)
+		return err
+	}
+
+	stream := NewScanner(packfile)
+	d, err := NewDecoder(stream, s)
+	if err != nil {
+		return err
+	}
+
+	_, err = d.Decode()
+	return err
+}