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, 196 insertions, 0 deletions

diff --git a/plumbing/transport/test/upload_pack.go b/plumbing/transport/test/upload_pack.go
new file mode 100644
index 0000000..5af4b29
--- /dev/null
+++ b/plumbing/transport/test/upload_pack.go
@@ -0,0 +1,196 @@
+// Package test implements common test suite for different transport
+// implementations.
+//
+package test
+
+import (
+	"bytes"
+	"io"
+	"io/ioutil"
+
+	"gopkg.in/src-d/go-git.v4/plumbing"
+	"gopkg.in/src-d/go-git.v4/plumbing/format/packfile"
+	"gopkg.in/src-d/go-git.v4/plumbing/protocol/packp"
+	"gopkg.in/src-d/go-git.v4/plumbing/transport"
+	"gopkg.in/src-d/go-git.v4/storage/memory"
+
+	. "gopkg.in/check.v1"
+	"gopkg.in/src-d/go-git.v4/plumbing/protocol/packp/capability"
+)
+
+type UploadPackSuite struct {
+	Endpoint            transport.Endpoint
+	EmptyEndpoint       transport.Endpoint
+	NonExistentEndpoint transport.Endpoint
+	Client              transport.Transport
+}
+
+func (s *UploadPackSuite) TestAdvertisedReferencesEmpty(c *C) {
+	r, err := s.Client.NewUploadPackSession(s.EmptyEndpoint)
+	c.Assert(err, IsNil)
+	ar, err := r.AdvertisedReferences()
+	c.Assert(err, Equals, transport.ErrEmptyRemoteRepository)
+	c.Assert(ar, IsNil)
+}
+
+func (s *UploadPackSuite) TestAdvertisedReferencesNotExists(c *C) {
+	r, err := s.Client.NewUploadPackSession(s.NonExistentEndpoint)
+	c.Assert(err, IsNil)
+	ar, err := r.AdvertisedReferences()
+	c.Assert(err, Equals, transport.ErrRepositoryNotFound)
+	c.Assert(ar, IsNil)
+
+	r, err = s.Client.NewUploadPackSession(s.NonExistentEndpoint)
+	c.Assert(err, IsNil)
+	req := packp.NewUploadPackRequest()
+	req.Wants = append(req.Wants, plumbing.NewHash("6ecf0ef2c2dffb796033e5a02219af86ec6584e5"))
+	reader, err := r.UploadPack(req)
+	c.Assert(err, Equals, transport.ErrRepositoryNotFound)
+	c.Assert(reader, IsNil)
+}
+
+func (s *UploadPackSuite) TestCallAdvertisedReferenceTwice(c *C) {
+	r, err := s.Client.NewUploadPackSession(s.Endpoint)
+	c.Assert(err, IsNil)
+	ar1, err := r.AdvertisedReferences()
+	c.Assert(err, IsNil)
+	c.Assert(ar1, NotNil)
+	ar2, err := r.AdvertisedReferences()
+	c.Assert(err, IsNil)
+	c.Assert(ar2, DeepEquals, ar1)
+}
+
+func (s *UploadPackSuite) TestDefaultBranch(c *C) {
+	r, err := s.Client.NewUploadPackSession(s.Endpoint)
+	c.Assert(err, IsNil)
+	defer func() { c.Assert(r.Close(), IsNil) }()
+
+	info, err := r.AdvertisedReferences()
+	c.Assert(err, IsNil)
+	symrefs := info.Capabilities.Get(capability.SymRef)
+	c.Assert(symrefs, HasLen, 1)
+	c.Assert(symrefs[0], Equals, "HEAD:refs/heads/master")
+}
+
+func (s *UploadPackSuite) TestAdvertisedReferencesFilterUnsupported(c *C) {
+	r, err := s.Client.NewUploadPackSession(s.Endpoint)
+	c.Assert(err, IsNil)
+	defer func() { c.Assert(r.Close(), IsNil) }()
+
+	info, err := r.AdvertisedReferences()
+	c.Assert(err, IsNil)
+	c.Assert(info.Capabilities.Supports(capability.MultiACK), Equals, false)
+}
+
+func (s *UploadPackSuite) TestCapabilities(c *C) {
+	r, err := s.Client.NewUploadPackSession(s.Endpoint)
+	c.Assert(err, IsNil)
+	defer func() { c.Assert(r.Close(), IsNil) }()
+
+	info, err := r.AdvertisedReferences()
+	c.Assert(err, IsNil)
+	c.Assert(info.Capabilities.Get(capability.Agent), HasLen, 1)
+}
+
+func (s *UploadPackSuite) TestFullUploadPack(c *C) {
+	r, err := s.Client.NewUploadPackSession(s.Endpoint)
+	c.Assert(err, IsNil)
+	defer func() { c.Assert(r.Close(), IsNil) }()
+
+	info, err := r.AdvertisedReferences()
+	c.Assert(err, IsNil)
+	c.Assert(info, NotNil)
+
+	req := packp.NewUploadPackRequest()
+	req.Wants = append(req.Wants, plumbing.NewHash("6ecf0ef2c2dffb796033e5a02219af86ec6584e5"))
+
+	reader, err := r.UploadPack(req)
+	c.Assert(err, IsNil)
+
+	s.checkObjectNumber(c, reader, 28)
+}
+
+func (s *UploadPackSuite) TestUploadPack(c *C) {
+	r, err := s.Client.NewUploadPackSession(s.Endpoint)
+	c.Assert(err, IsNil)
+	defer func() { c.Assert(r.Close(), IsNil) }()
+
+	req := packp.NewUploadPackRequest()
+	req.Wants = append(req.Wants, plumbing.NewHash("6ecf0ef2c2dffb796033e5a02219af86ec6584e5"))
+
+	reader, err := r.UploadPack(req)
+	c.Assert(err, IsNil)
+
+	s.checkObjectNumber(c, reader, 28)
+}
+
+func (s *UploadPackSuite) TestUploadPackInvalidReq(c *C) {
+	r, err := s.Client.NewUploadPackSession(s.Endpoint)
+	c.Assert(err, IsNil)
+	defer func() { c.Assert(r.Close(), IsNil) }()
+
+	req := packp.NewUploadPackRequest()
+	req.Wants = append(req.Wants, plumbing.NewHash("6ecf0ef2c2dffb796033e5a02219af86ec6584e5"))
+	req.Capabilities.Set(capability.Sideband)
+	req.Capabilities.Set(capability.Sideband64k)
+
+	_, err = r.UploadPack(req)
+	c.Assert(err, NotNil)
+}
+
+func (s *UploadPackSuite) TestUploadPackNoChanges(c *C) {
+	r, err := s.Client.NewUploadPackSession(s.Endpoint)
+	c.Assert(err, IsNil)
+	defer func() { c.Assert(r.Close(), IsNil) }()
+
+	req := packp.NewUploadPackRequest()
+	req.Wants = append(req.Wants, plumbing.NewHash("6ecf0ef2c2dffb796033e5a02219af86ec6584e5"))
+	req.Haves = append(req.Haves, plumbing.NewHash("6ecf0ef2c2dffb796033e5a02219af86ec6584e5"))
+
+	reader, err := r.UploadPack(req)
+	c.Assert(err, Equals, transport.ErrEmptyUploadPackRequest)
+	c.Assert(reader, IsNil)
+}
+
+func (s *UploadPackSuite) TestUploadPackMulti(c *C) {
+	r, err := s.Client.NewUploadPackSession(s.Endpoint)
+	c.Assert(err, IsNil)
+	defer func() { c.Assert(r.Close(), IsNil) }()
+
+	req := packp.NewUploadPackRequest()
+	req.Wants = append(req.Wants, plumbing.NewHash("6ecf0ef2c2dffb796033e5a02219af86ec6584e5"))
+	req.Wants = append(req.Wants, plumbing.NewHash("e8d3ffab552895c19b9fcf7aa264d277cde33881"))
+
+	reader, err := r.UploadPack(req)
+	c.Assert(err, IsNil)
+
+	s.checkObjectNumber(c, reader, 31)
+}
+
+func (s *UploadPackSuite) TestFetchError(c *C) {
+	r, err := s.Client.NewUploadPackSession(s.Endpoint)
+	c.Assert(err, IsNil)
+
+	req := packp.NewUploadPackRequest()
+	req.Wants = append(req.Wants, plumbing.NewHash("1111111111111111111111111111111111111111"))
+
+	reader, err := r.UploadPack(req)
+	c.Assert(err, NotNil)
+	c.Assert(reader, IsNil)
+
+	//XXX: We do not test Close error, since implementations might return
+	//     different errors if a previous error was found.
+}
+
+func (s *UploadPackSuite) checkObjectNumber(c *C, r io.Reader, n int) {
+	b, err := ioutil.ReadAll(r)
+	c.Assert(err, IsNil)
+	buf := bytes.NewBuffer(b)
+	scanner := packfile.NewScanner(buf)
+	storage := memory.NewStorage()
+	d, err := packfile.NewDecoder(scanner, storage)
+	c.Assert(err, IsNil)
+	_, err = d.Decode()
+	c.Assert(err, IsNil)
+	c.Assert(len(storage.Objects), Equals, n)
+}