package git import ( "errors" "fmt" "io" "gopkg.in/src-d/go-git.v4/config" "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/object" "gopkg.in/src-d/go-git.v4/plumbing/protocol/packp" "gopkg.in/src-d/go-git.v4/plumbing/protocol/packp/capability" "gopkg.in/src-d/go-git.v4/plumbing/protocol/packp/sideband" "gopkg.in/src-d/go-git.v4/plumbing/revlist" "gopkg.in/src-d/go-git.v4/plumbing/storer" "gopkg.in/src-d/go-git.v4/plumbing/transport" "gopkg.in/src-d/go-git.v4/plumbing/transport/client" "gopkg.in/src-d/go-git.v4/storage" "gopkg.in/src-d/go-git.v4/storage/memory" "gopkg.in/src-d/go-git.v4/utils/ioutil" ) var NoErrAlreadyUpToDate = errors.New("already up-to-date") // Remote represents a connection to a remote repository. type Remote struct { c *config.RemoteConfig s storage.Storer } func newRemote(s storage.Storer, c *config.RemoteConfig) *Remote { return &Remote{s: s, c: c} } // Config returns the RemoteConfig object used to instantiate this Remote. func (r *Remote) Config() *config.RemoteConfig { return r.c } func (r *Remote) String() string { fetch := r.c.URL push := r.c.URL return fmt.Sprintf("%s\t%s (fetch)\n%[1]s\t%[3]s (push)", r.c.Name, fetch, push) } // Fetch fetches references from the remote to the local repository. // Returns nil if the operation is successful, NoErrAlreadyUpToDate if there are // no changes to be fetched and no local references to update, or an error. func (r *Remote) Fetch(o *FetchOptions) error { _, err := r.fetch(o) return err } // Push performs a push to the remote. Returns NoErrAlreadyUpToDate if the // remote was already up-to-date. func (r *Remote) Push(o *PushOptions) (err error) { // TODO: Support deletes. // TODO: Sideband support if o.RemoteName == "" { o.RemoteName = r.c.Name } if err := o.Validate(); err != nil { return err } if o.RemoteName != r.c.Name { return fmt.Errorf("remote names don't match: %s != %s", o.RemoteName, r.c.Name) } s, err := newSendPackSession(r.c.URL, o.Auth) if err != nil { return err } defer ioutil.CheckClose(s, &err) ar, err := s.AdvertisedReferences() if err != nil { return err } remoteRefs, err := ar.AllReferences() if err != nil { return err } req := packp.NewReferenceUpdateRequestFromCapabilities(ar.Capabilities) if err := r.addReferencesToUpdate(o.RefSpecs, remoteRefs, req); err != nil { return err } if len(req.Commands) == 0 { return NoErrAlreadyUpToDate } objects, err := objectsToPush(req.Commands) if err != nil { return err } haves, err := referencesToHashes(remoteRefs) if err != nil { return err } hashesToPush, err := revlist.Objects(r.s, objects, haves) if err != nil { return err } rs, err := pushHashes(s, r.s, req, hashesToPush) if err != nil { return err } return rs.Error() } func (r *Remote) fetch(o *FetchOptions) (refs storer.ReferenceStorer, err error) { if o.RemoteName == "" { o.RemoteName = r.c.Name } if err := o.Validate(); err != nil { return nil, err } if len(o.RefSpecs) == 0 { o.RefSpecs = r.c.Fetch } s, err := newUploadPackSession(r.c.URL, o.Auth) if err != nil { return nil, err } defer ioutil.CheckClose(s, &err) ar, err := s.AdvertisedReferences() if err != nil { return nil, err } req, err := r.newUploadPackRequest(o, ar) if err != nil { return nil, err } remoteRefs, err := ar.AllReferences() if err != nil { return nil, err } req.Wants, err = getWants(o.RefSpecs, r.s, remoteRefs) if len(req.Wants) > 0 { req.Haves, err = getHaves(r.s) if err != nil { return nil, err } if err := r.fetchPack(o, s, req); err != nil { return nil, err } } err = r.updateLocalReferenceStorage(o.RefSpecs, remoteRefs) if err != nil && err != NoErrAlreadyUpToDate { return nil, err } if len(req.Wants) == 0 { return remoteRefs, err } return remoteRefs, nil } func newUploadPackSession(url string, auth transport.AuthMethod) (transport.UploadPackSession, error) { c, ep, err := newClient(url) if err != nil { return nil, err } return c.NewUploadPackSession(ep, auth) } func newSendPackSession(url string, auth transport.AuthMethod) (transport.ReceivePackSession, error) { c, ep, err := newClient(url) if err != nil { return nil, err } return c.NewReceivePackSession(ep, auth) } func newClient(url string) (transport.Transport, transport.Endpoint, error) { ep, err := transport.NewEndpoint(url) if err != nil { return nil, nil, err } c, err := client.NewClient(ep) if err != nil { return nil, nil, err } return c, ep, err } func (r *Remote) fetchPack(o *FetchOptions, s transport.UploadPackSession, req *packp.UploadPackRequest) (err error) { reader, err := s.UploadPack(req) if err != nil { return err } defer ioutil.CheckClose(reader, &err) if err := r.updateShallow(o, reader); err != nil { return err } if err = packfile.UpdateObjectStorage(r.s, buildSidebandIfSupported(req.Capabilities, reader, o.Progress), ); err != nil { return err } return err } func (r *Remote) addReferencesToUpdate(refspecs []config.RefSpec, remoteRefs storer.ReferenceStorer, req *packp.ReferenceUpdateRequest) error { for _, rs := range refspecs { iter, err := r.s.IterReferences() if err != nil { return err } err = iter.ForEach(func(ref *plumbing.Reference) error { return r.addReferenceIfRefSpecMatches( rs, remoteRefs, ref, req, ) }) if err != nil { return err } } return nil } func (r *Remote) addReferenceIfRefSpecMatches(rs config.RefSpec, remoteRefs storer.ReferenceStorer, localRef *plumbing.Reference, req *packp.ReferenceUpdateRequest) error { if localRef.Type() != plumbing.HashReference { return nil } if !rs.Match(localRef.Name()) { return nil } cmd := &packp.Command{ Name: rs.Dst(localRef.Name()), Old: plumbing.ZeroHash, New: localRef.Hash(), } remoteRef, err := remoteRefs.Reference(cmd.Name) if err == nil { if remoteRef.Type() != plumbing.HashReference { //TODO: check actual git behavior here return nil } cmd.Old = remoteRef.Hash() } else if err != plumbing.ErrReferenceNotFound { return err } if cmd.Old == cmd.New { return nil } if !rs.IsForceUpdate() { if err := checkFastForwardUpdate(r.s, remoteRefs, cmd); err != nil { return err } } req.Commands = append(req.Commands, cmd) return nil } func getHaves(localRefs storer.ReferenceStorer) ([]plumbing.Hash, error) { iter, err := localRefs.IterReferences() if err != nil { return nil, err } var haves []plumbing.Hash err = iter.ForEach(func(ref *plumbing.Reference) error { if ref.Type() != plumbing.HashReference { return nil } haves = append(haves, ref.Hash()) return nil }) if err != nil { return nil, err } return haves, nil } func getWants( spec []config.RefSpec, localStorer storage.Storer, remoteRefs storer.ReferenceStorer, ) ([]plumbing.Hash, error) { wantTags := true for _, s := range spec { if !s.IsWildcard() { wantTags = false break } } iter, err := remoteRefs.IterReferences() if err != nil { return nil, err } wants := map[plumbing.Hash]bool{} err = iter.ForEach(func(ref *plumbing.Reference) error { if !config.MatchAny(spec, ref.Name()) { if !ref.IsTag() || !wantTags { return nil } } if ref.Type() == plumbing.SymbolicReference { ref, err = storer.ResolveReference(remoteRefs, ref.Name()) if err != nil { return err } } if ref.Type() != plumbing.HashReference { return nil } hash := ref.Hash() exists, err := objectExists(localStorer, hash) if err != nil { return err } if !exists { wants[hash] = true } return nil }) if err != nil { return nil, err } var result []plumbing.Hash for h := range wants { result = append(result, h) } return result, nil } func objectExists(s storer.EncodedObjectStorer, h plumbing.Hash) (bool, error) { _, err := s.EncodedObject(plumbing.AnyObject, h) if err == plumbing.ErrObjectNotFound { return false, nil } return true, err } func checkFastForwardUpdate(s storer.EncodedObjectStorer, remoteRefs storer.ReferenceStorer, cmd *packp.Command) error { if cmd.Old == plumbing.ZeroHash { _, err := remoteRefs.Reference(cmd.Name) if err == plumbing.ErrReferenceNotFound { return nil } if err != nil { return err } return fmt.Errorf("non-fast-forward update: %s", cmd.Name.String()) } ff, err := isFastForward(s, cmd.Old, cmd.New) if err != nil { return err } if !ff { return fmt.Errorf("non-fast-forward update: %s", cmd.Name.String()) } return nil } func isFastForward(s storer.EncodedObjectStorer, old, new plumbing.Hash) (bool, error) { c, err := object.GetCommit(s, new) if err != nil { return false, err } found := false iter := object.NewCommitPreorderIter(c) return found, iter.ForEach(func(c *object.Commit) error { if c.Hash != old { return nil } found = true return storer.ErrStop }) } func (r *Remote) newUploadPackRequest(o *FetchOptions, ar *packp.AdvRefs) (*packp.UploadPackRequest, error) { req := packp.NewUploadPackRequestFromCapabilities(ar.Capabilities) if o.Depth != 0 { req.Depth = packp.DepthCommits(o.Depth) if err := req.Capabilities.Set(capability.Shallow); err != nil { return nil, err } } if o.Progress == nil && ar.Capabilities.Supports(capability.NoProgress) { if err := req.Capabilities.Set(capability.NoProgress); err != nil { return nil, err } } return req, nil } func buildSidebandIfSupported(l *capability.List, reader io.Reader, p sideband.Progress) io.Reader { var t sideband.Type switch { case l.Supports(capability.Sideband): t = sideband.Sideband case l.Supports(capability.Sideband64k): t = sideband.Sideband64k default: return reader } d := sideband.NewDemuxer(t, reader) d.Progress = p return d } func (r *Remote) updateLocalReferenceStorage(specs []config.RefSpec, refs memory.ReferenceStorage) error { updated := false for _, spec := range specs { for _, ref := range refs { if !spec.Match(ref.Name()) { continue } if ref.Type() != plumbing.HashReference { continue } name := spec.Dst(ref.Name()) sref, err := r.s.Reference(name) if err != nil && err != plumbing.ErrReferenceNotFound { return err } if err == plumbing.ErrReferenceNotFound || sref.Hash() != ref.Hash() { n := plumbing.NewHashReference(name, ref.Hash()) if err := r.s.SetReference(n); err != nil { return err } updated = true } } } if err := r.buildFetchedTags(refs); err != nil { return err } if !updated { return NoErrAlreadyUpToDate } return nil } func (r *Remote) buildFetchedTags(refs memory.ReferenceStorage) error { updated := false for _, ref := range refs { if !ref.IsTag() { continue } _, err := r.s.EncodedObject(plumbing.AnyObject, ref.Hash()) if err == plumbing.ErrObjectNotFound { continue } if err != nil { return err } if err = r.s.SetReference(ref); err != nil { return err } updated = true } if !updated { return NoErrAlreadyUpToDate } return nil } func objectsToPush(commands []*packp.Command) ([]plumbing.Hash, error) { var objects []plumbing.Hash for _, cmd := range commands { if cmd.New == plumbing.ZeroHash { continue } objects = append(objects, cmd.New) } return objects, nil } func referencesToHashes(refs storer.ReferenceStorer) ([]plumbing.Hash, error) { iter, err := refs.IterReferences() if err != nil { return nil, err } var hs []plumbing.Hash err = iter.ForEach(func(ref *plumbing.Reference) error { if ref.Type() != plumbing.HashReference { return nil } hs = append(hs, ref.Hash()) return nil }) if err != nil { return nil, err } return hs, nil } func pushHashes(sess transport.ReceivePackSession, sto storer.EncodedObjectStorer, req *packp.ReferenceUpdateRequest, hs []plumbing.Hash) (*packp.ReportStatus, error) { rd, wr := io.Pipe() req.Packfile = rd done := make(chan error) go func() { e := packfile.NewEncoder(wr, sto, false) if _, err := e.Encode(hs); err != nil { done <- wr.CloseWithError(err) return } done <- wr.Close() }() rs, err := sess.ReceivePack(req) if err != nil { return nil, err } if err := <-done; err != nil { return nil, err } return rs, nil } func (r *Remote) updateShallow(o *FetchOptions, resp *packp.UploadPackResponse) error { if o.Depth == 0 { return nil } return r.s.SetShallow(resp.Shallows) }