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.

6 files changed, 62 insertions, 61 deletions

diff --git a/plumbing/transport/http/common.go b/plumbing/transport/http/common.go
index aa3425e..957fd07 100644
--- a/plumbing/transport/http/common.go
+++ b/plumbing/transport/http/common.go
@@ -25,7 +25,7 @@ var DefaultClient = NewClient(nil)
 // Note that for HTTP client cannot distinguist between private repositories and
 // unexistent repositories on GitHub. So it returns `ErrAuthorizationRequired`
 // for both.
-func NewClient(c *http.Client) transport.Client {
+func NewClient(c *http.Client) transport.Transport {
 	if c == nil {
 		return &client{http.DefaultClient}
 	}
@@ -35,16 +35,16 @@ func NewClient(c *http.Client) transport.Client {
 	}
 }
 
-func (c *client) NewFetchPackSession(ep transport.Endpoint) (
-	transport.FetchPackSession, error) {
+func (c *client) NewUploadPackSession(ep transport.Endpoint) (
+	transport.UploadPackSession, error) {
 
-	return newFetchPackSession(c.c, ep), nil
+	return newUploadPackSession(c.c, ep), nil
 }
 
-func (c *client) NewSendPackSession(ep transport.Endpoint) (
-	transport.SendPackSession, error) {
+func (c *client) NewReceivePackSession(ep transport.Endpoint) (
+	transport.ReceivePackSession, error) {
 
-	return newSendPackSession(c.c, ep), nil
+	return newReceivePackSession(c.c, ep), nil
 }
 
 type session struct {
diff --git a/plumbing/transport/http/common_test.go b/plumbing/transport/http/common_test.go
index 432bd07..217999d 100644
--- a/plumbing/transport/http/common_test.go
+++ b/plumbing/transport/http/common_test.go
@@ -26,7 +26,7 @@ func (s *ClientSuite) SetUpSuite(c *C) {
 	c.Assert(err, IsNil)
 }
 
-func (s *FetchPackSuite) TestNewClient(c *C) {
+func (s *UploadPackSuite) TestNewClient(c *C) {
 	roundTripper := &http.Transport{
 		TLSClientConfig: &tls.Config{InsecureSkipVerify: true},
 	}
@@ -76,10 +76,10 @@ func (s *ClientSuite) testNewHTTPError(c *C, code int, msg string) {
 
 func (s *ClientSuite) TestSetAuth(c *C) {
 	auth := &BasicAuth{}
-	r, err := DefaultClient.NewFetchPackSession(s.Endpoint)
+	r, err := DefaultClient.NewUploadPackSession(s.Endpoint)
 	c.Assert(err, IsNil)
 	r.SetAuth(auth)
-	c.Assert(auth, Equals, r.(*fetchPackSession).auth)
+	c.Assert(auth, Equals, r.(*upSession).auth)
 }
 
 type mockAuth struct{}
@@ -88,7 +88,7 @@ func (*mockAuth) Name() string   { return "" }
 func (*mockAuth) String() string { return "" }
 
 func (s *ClientSuite) TestSetAuthWrongType(c *C) {
-	r, err := DefaultClient.NewFetchPackSession(s.Endpoint)
+	r, err := DefaultClient.NewUploadPackSession(s.Endpoint)
 	c.Assert(err, IsNil)
 	c.Assert(r.SetAuth(&mockAuth{}), Equals, transport.ErrInvalidAuthMethod)
 }
diff --git a/plumbing/transport/http/receive_pack.go b/plumbing/transport/http/receive_pack.go
new file mode 100644
index 0000000..a8384c7
--- /dev/null
+++ b/plumbing/transport/http/receive_pack.go
@@ -0,0 +1,30 @@
+package http
+
+import (
+	"errors"
+	"net/http"
+
+	"gopkg.in/src-d/go-git.v4/plumbing/protocol/packp"
+	"gopkg.in/src-d/go-git.v4/plumbing/transport"
+)
+
+var errReceivePackNotSupported = errors.New("receive-pack not supported yet")
+
+type rpSession struct {
+	*session
+}
+
+func newReceivePackSession(c *http.Client, ep transport.Endpoint) transport.ReceivePackSession {
+	return &rpSession{&session{}}
+}
+
+func (s *rpSession) AdvertisedReferences() (*packp.AdvRefs, error) {
+
+	return nil, errReceivePackNotSupported
+}
+
+func (s *rpSession) ReceivePack(*packp.ReferenceUpdateRequest) (
+	*packp.ReportStatus, error) {
+
+	return nil, errReceivePackNotSupported
+}
diff --git a/plumbing/transport/http/send_pack.go b/plumbing/transport/http/send_pack.go
deleted file mode 100644
index 43464ae..0000000
--- a/plumbing/transport/http/send_pack.go
+++ /dev/null
@@ -1,30 +0,0 @@
-package http
-
-import (
-	"errors"
-	"net/http"
-
-	"gopkg.in/src-d/go-git.v4/plumbing/protocol/packp"
-	"gopkg.in/src-d/go-git.v4/plumbing/transport"
-)
-
-var errSendPackNotSupported = errors.New("send-pack not supported yet")
-
-type sendPackSession struct {
-	*session
-}
-
-func newSendPackSession(c *http.Client, ep transport.Endpoint) transport.SendPackSession {
-	return &sendPackSession{&session{}}
-}
-
-func (s *sendPackSession) AdvertisedReferences() (*packp.AdvRefs, error) {
-
-	return nil, errSendPackNotSupported
-}
-
-func (s *sendPackSession) SendPack(*packp.ReferenceUpdateRequest) (
-	*packp.ReportStatus, error) {
-
-	return nil, errSendPackNotSupported
-}
diff --git a/plumbing/transport/http/fetch_pack.go b/plumbing/transport/http/upload_pack.go
index 0c85be4..26257f5 100644
--- a/plumbing/transport/http/fetch_pack.go
+++ b/plumbing/transport/http/upload_pack.go
@@ -15,14 +15,14 @@ import (
 	"gopkg.in/src-d/go-git.v4/utils/ioutil"
 )
 
-type fetchPackSession struct {
+type upSession struct {
 	*session
 }
 
-func newFetchPackSession(c *http.Client,
-	ep transport.Endpoint) transport.FetchPackSession {
+func newUploadPackSession(c *http.Client,
+	ep transport.Endpoint) transport.UploadPackSession {
 
-	return &fetchPackSession{
+	return &upSession{
 		session: &session{
 			auth:     basicAuthFromEndpoint(ep),
 			client:   c,
@@ -31,7 +31,7 @@ func newFetchPackSession(c *http.Client,
 	}
 }
 
-func (s *fetchPackSession) AdvertisedReferences() (*packp.AdvRefs, error) {
+func (s *upSession) AdvertisedReferences() (*packp.AdvRefs, error) {
 	if s.advRefs != nil {
 		return s.advRefs, nil
 	}
@@ -73,7 +73,7 @@ func (s *fetchPackSession) AdvertisedReferences() (*packp.AdvRefs, error) {
 	return ar, nil
 }
 
-func (s *fetchPackSession) FetchPack(req *packp.UploadPackRequest) (*packp.UploadPackResponse, error) {
+func (s *upSession) UploadPack(req *packp.UploadPackRequest) (*packp.UploadPackResponse, error) {
 	if req.IsEmpty() {
 		return nil, transport.ErrEmptyUploadPackRequest
 	}
@@ -111,11 +111,11 @@ func (s *fetchPackSession) FetchPack(req *packp.UploadPackRequest) (*packp.Uploa
 }
 
 // Close does nothing.
-func (s *fetchPackSession) Close() error {
+func (s *upSession) Close() error {
 	return nil
 }
 
-func (s *fetchPackSession) doRequest(method, url string, content *bytes.Buffer) (*http.Response, error) {
+func (s *upSession) doRequest(method, url string, content *bytes.Buffer) (*http.Response, error) {
 	var body io.Reader
 	if content != nil {
 		body = content
@@ -143,7 +143,7 @@ func (s *fetchPackSession) doRequest(method, url string, content *bytes.Buffer)
 }
 
 // it requires a bytes.Buffer, because we need to know the length
-func (s *fetchPackSession) applyHeadersToRequest(req *http.Request, content *bytes.Buffer) {
+func (s *upSession) applyHeadersToRequest(req *http.Request, content *bytes.Buffer) {
 	req.Header.Add("User-Agent", "git/1.0")
 	req.Header.Add("Host", s.endpoint.Host)
 
diff --git a/plumbing/transport/http/fetch_pack_test.go b/plumbing/transport/http/upload_pack_test.go
index 6c40e60..d3e4989 100644
--- a/plumbing/transport/http/fetch_pack_test.go
+++ b/plumbing/transport/http/upload_pack_test.go
@@ -11,37 +11,38 @@ import (
 	. "gopkg.in/check.v1"
 )
 
-type FetchPackSuite struct {
-	test.FetchPackSuite
+type UploadPackSuite struct {
+	test.UploadPackSuite
 }
 
-var _ = Suite(&FetchPackSuite{})
+var _ = Suite(&UploadPackSuite{})
 
-func (s *FetchPackSuite) SetUpSuite(c *C) {
-	s.FetchPackSuite.Client = DefaultClient
+func (s *UploadPackSuite) SetUpSuite(c *C) {
+	s.UploadPackSuite.Client = DefaultClient
 
 	ep, err := transport.NewEndpoint("https://github.com/git-fixtures/basic.git")
 	c.Assert(err, IsNil)
-	s.FetchPackSuite.Endpoint = ep
+	s.UploadPackSuite.Endpoint = ep
 
 	ep, err = transport.NewEndpoint("https://github.com/git-fixtures/empty.git")
 	c.Assert(err, IsNil)
-	s.FetchPackSuite.EmptyEndpoint = ep
+	s.UploadPackSuite.EmptyEndpoint = ep
 
 	ep, err = transport.NewEndpoint("https://github.com/git-fixtures/non-existent.git")
 	c.Assert(err, IsNil)
-	s.FetchPackSuite.NonExistentEndpoint = ep
+	s.UploadPackSuite.NonExistentEndpoint = ep
 }
 
-func (s *FetchPackSuite) TestInfoNotExists(c *C) {
-	r, err := s.Client.NewFetchPackSession(s.NonExistentEndpoint)
+// Overwritten, different behaviour for HTTP.
+func (s *UploadPackSuite) TestAdvertisedReferencesNotExists(c *C) {
+	r, err := s.Client.NewUploadPackSession(s.NonExistentEndpoint)
 	c.Assert(err, IsNil)
 	info, err := r.AdvertisedReferences()
 	c.Assert(err, Equals, transport.ErrAuthorizationRequired)
 	c.Assert(info, IsNil)
 }
 
-func (s *FetchPackSuite) TestuploadPackRequestToReader(c *C) {
+func (s *UploadPackSuite) TestuploadPackRequestToReader(c *C) {
 	r := packp.NewUploadPackRequest()
 	r.Wants = append(r.Wants, plumbing.NewHash("d82f291cde9987322c8a0c81a325e1ba6159684c"))
 	r.Wants = append(r.Wants, plumbing.NewHash("2b41ef280fdb67a9b250678686a0c3e03b0a9989"))