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, 29 insertions, 1 deletions

diff --git a/plumbing/protocol/packp/uppackresp.go b/plumbing/protocol/packp/uppackresp.go
index a117956..ac456f3 100644
--- a/plumbing/protocol/packp/uppackresp.go
+++ b/plumbing/protocol/packp/uppackresp.go
@@ -5,6 +5,7 @@ import (
 	"io"
 
 	"gopkg.in/src-d/go-git.v4/plumbing/protocol/packp/capability"
+	"gopkg.in/src-d/go-git.v4/utils/ioutil"
 )
 
 // ErrUploadPackResponseNotDecoded is returned if Read is called without
@@ -17,8 +18,8 @@ var ErrUploadPackResponseNotDecoded = errors.New("upload-pack-response should be
 type UploadPackResponse struct {
 	ShallowUpdate
 	ServerResponse
-	r io.ReadCloser
 
+	r          io.ReadCloser
 	isShallow  bool
 	isMultiACK bool
 	isOk       bool
@@ -37,6 +38,16 @@ func NewUploadPackResponse(req *UploadPackRequest) *UploadPackResponse {
 	}
 }
 
+// NewUploadPackResponseWithPackfile creates a new UploadPackResponse instance,
+// and sets its packfile reader.
+func NewUploadPackResponseWithPackfile(req *UploadPackRequest,
+	pf io.ReadCloser) *UploadPackResponse {
+
+	r := NewUploadPackResponse(req)
+	r.r = pf
+	return r
+}
+
 // Decode decodes all the responses sent by upload-pack service into the struct
 // and prepares it to read the packfile using the Read method
 func (r *UploadPackResponse) Decode(reader io.ReadCloser) error {
@@ -56,6 +67,23 @@ func (r *UploadPackResponse) Decode(reader io.ReadCloser) error {
 	return nil
 }
 
+// Encode encodes an UploadPackResponse.
+func (r *UploadPackResponse) Encode(w io.Writer) (err error) {
+	if r.isShallow {
+		if err := r.ShallowUpdate.Encode(w); err != nil {
+			return err
+		}
+	}
+
+	if err := r.ServerResponse.Encode(w); err != nil {
+		return err
+	}
+
+	defer ioutil.CheckClose(r.r, &err)
+	_, err = io.Copy(w, r.r)
+	return err
+}
+
 // Read reads the packfile data, if the request was done with any Sideband
 // capability the content read should be demultiplexed. If the methods wasn't
 // called before the ErrUploadPackResponseNotDecoded will be return