repository: allow push from shallow repositories

plumbing/object/commit_walker.go

@@ -18,10 +18,16 @@ type commitPreIterator struct {
 // The given callback will be called for each visited commit. Each commit will
 // be visited only once. If the callback returns an error, walking will stop
 // and will return the error. Other errors might be returned if the history
-// cannot be traversed (e.g. missing objects).
-func NewCommitPreorderIter(c *Commit) CommitIter {
+// cannot be traversed (e.g. missing objects). Ignore allows to skip some
+// commits from being iterated.
+func NewCommitPreorderIter(c *Commit, ignore []plumbing.Hash) CommitIter {
+	seen := make(map[plumbing.Hash]bool)
+	for _, h := range ignore {
+		seen[h] = true
+	}
+
 	return &commitPreIterator{
-		seen:  make(map[plumbing.Hash]bool),
+		seen:  seen,
 		stack: make([]CommitIter, 0),
 		start: c,
 	}
@@ -51,20 +57,33 @@ func (w *commitPreIterator) Next() (*Commit, error) {
 			}
 		}
 
-		// check and update seen
 		if w.seen[c.Hash] {
 			continue
 		}
 
 		w.seen[c.Hash] = true
+
 		if c.NumParents() > 0 {
-			w.stack = append(w.stack, c.Parents())
+			w.stack = append(w.stack, filteredParentIter(c, w.seen))
 		}
 
 		return c, nil
 	}
 }
 
+func filteredParentIter(c *Commit, seen map[plumbing.Hash]bool) CommitIter {
+	var hashes []plumbing.Hash
+	for _, h := range c.ParentHashes {
+		if !seen[h] {
+			hashes = append(hashes, h)
+		}
+	}
+
+	return NewCommitIter(c.s,
+		storer.NewEncodedObjectLookupIter(c.s, plumbing.CommitObject, hashes),
+	)
+}
+
 func (w *commitPreIterator) ForEach(cb func(*Commit) error) error {
 	for {
 		c, err := w.Next()
@@ -98,11 +117,16 @@ type commitPostIterator struct {
 // history like WalkCommitHistory but in post-order. This means that after
 // walking a merge commit, the merged commit will be walked before the base
 // it was merged on. This can be useful if you wish to see the history in
-// chronological order.
-func NewCommitPostorderIter(c *Commit) CommitIter {
+// chronological order. Ignore allows to skip some commits from being iterated.
+func NewCommitPostorderIter(c *Commit, ignore []plumbing.Hash) CommitIter {
+	seen := make(map[plumbing.Hash]bool)
+	for _, h := range ignore {
+		seen[h] = true
+	}
+
 	return &commitPostIterator{
 		stack: []*Commit{c},
-		seen:  make(map[plumbing.Hash]bool),
+		seen:  seen,
 	}
 }
 
@@ -114,17 +138,17 @@ func (w *commitPostIterator) Next() (*Commit, error) {
 
 		c := w.stack[len(w.stack)-1]
 		w.stack = w.stack[:len(w.stack)-1]
+
 		if w.seen[c.Hash] {
 			continue
 		}
+
 		w.seen[c.Hash] = true
 
-		err := c.Parents().ForEach(func(pcm *Commit) error {
-			w.stack = append(w.stack, pcm)
+		return c, c.Parents().ForEach(func(p *Commit) error {
+			w.stack = append(w.stack, p)
 			return nil
 		})
-
-		return c, err
 	}
 }
 

plumbing/object/commit_walker_test.go

@@ -1,6 +1,10 @@
 package object
 
-import . "gopkg.in/check.v1"
+import (
+	"gopkg.in/src-d/go-git.v4/plumbing"
+
+	. "gopkg.in/check.v1"
+)
 
 type CommitWalkerSuite struct {
 	BaseObjectsSuite
@@ -12,8 +16,7 @@ func (s *CommitWalkerSuite) TestCommitPreIterator(c *C) {
 	commit := s.commit(c, s.Fixture.Head)
 
 	var commits []*Commit
-	wIter := NewCommitPreorderIter(commit)
-	wIter.ForEach(func(c *Commit) error {
+	NewCommitPreorderIter(commit, nil).ForEach(func(c *Commit) error {
 		commits = append(commits, c)
 		return nil
 	})
@@ -35,12 +38,33 @@ func (s *CommitWalkerSuite) TestCommitPreIterator(c *C) {
 	}
 }
 
+func (s *CommitWalkerSuite) TestCommitPreIteratorWithIgnore(c *C) {
+	commit := s.commit(c, s.Fixture.Head)
+
+	var commits []*Commit
+	NewCommitPreorderIter(commit, []plumbing.Hash{
+		plumbing.NewHash("af2d6a6954d532f8ffb47615169c8fdf9d383a1a"),
+	}).ForEach(func(c *Commit) error {
+		commits = append(commits, c)
+		return nil
+	})
+
+	c.Assert(commits, HasLen, 2)
+
+	expected := []string{
+		"6ecf0ef2c2dffb796033e5a02219af86ec6584e5",
+		"918c48b83bd081e863dbe1b80f8998f058cd8294",
+	}
+	for i, commit := range commits {
+		c.Assert(commit.Hash.String(), Equals, expected[i])
+	}
+}
+
 func (s *CommitWalkerSuite) TestCommitPostIterator(c *C) {
 	commit := s.commit(c, s.Fixture.Head)
 
 	var commits []*Commit
-	wIter := NewCommitPostorderIter(commit)
-	wIter.ForEach(func(c *Commit) error {
+	NewCommitPostorderIter(commit, nil).ForEach(func(c *Commit) error {
 		commits = append(commits, c)
 		return nil
 	})
@@ -57,6 +81,29 @@ func (s *CommitWalkerSuite) TestCommitPostIterator(c *C) {
 		"b029517f6300c2da0f4b651b8642506cd6aaf45d",
 		"35e85108805c84807bc66a02d91535e1e24b38b9",
 	}
+
+	for i, commit := range commits {
+		c.Assert(commit.Hash.String(), Equals, expected[i])
+	}
+}
+
+func (s *CommitWalkerSuite) TestCommitPostIteratorWithIgnore(c *C) {
+	commit := s.commit(c, s.Fixture.Head)
+
+	var commits []*Commit
+	NewCommitPostorderIter(commit, []plumbing.Hash{
+		plumbing.NewHash("af2d6a6954d532f8ffb47615169c8fdf9d383a1a"),
+	}).ForEach(func(c *Commit) error {
+		commits = append(commits, c)
+		return nil
+	})
+
+	c.Assert(commits, HasLen, 2)
+
+	expected := []string{
+		"6ecf0ef2c2dffb796033e5a02219af86ec6584e5",
+		"918c48b83bd081e863dbe1b80f8998f058cd8294",
+	}
 	for i, commit := range commits {
 		c.Assert(commit.Hash.String(), Equals, expected[i])
 	}

plumbing/revlist/revlist.go

@@ -16,11 +16,7 @@ import (
 // the reachable objects from the given objects. Ignore param are object hashes
 // that we want to ignore on the result. All that objects must be accessible
 // from the object storer.
-func Objects(
-	s storer.EncodedObjectStorer,
-	objects []plumbing.Hash,
-	ignore []plumbing.Hash) ([]plumbing.Hash, error) {
-
+func Objects(s storer.EncodedObjectStorer, objects, ignore []plumbing.Hash) ([]plumbing.Hash, error) {
 	seen := hashListToSet(ignore)
 	result := make(map[plumbing.Hash]bool)
 
@@ -32,7 +28,7 @@ func Objects(
 	}
 
 	for _, h := range objects {
-		if err := processObject(s, h, seen, walkerFunc); err != nil {
+		if err := processObject(s, h, seen, ignore, walkerFunc); err != nil {
 			return nil, err
 		}
 	}
@@ -45,6 +41,7 @@ func processObject(
 	s storer.EncodedObjectStorer,
 	h plumbing.Hash,
 	seen map[plumbing.Hash]bool,
+	ignore []plumbing.Hash,
 	walkerFunc func(h plumbing.Hash),
 ) error {
 	o, err := s.EncodedObject(plumbing.AnyObject, h)
@@ -59,12 +56,12 @@ func processObject(
 
 	switch do := do.(type) {
 	case *object.Commit:
-		return reachableObjects(do, seen, walkerFunc)
+		return reachableObjects(do, seen, ignore, walkerFunc)
 	case *object.Tree:
 		return iterateCommitTrees(seen, do, walkerFunc)
 	case *object.Tag:
 		walkerFunc(do.Hash)
-		return processObject(s, do.Target, seen, walkerFunc)
+		return processObject(s, do.Target, seen, ignore, walkerFunc)
 	case *object.Blob:
 		walkerFunc(do.Hash)
 	default:
@@ -82,22 +79,24 @@ func processObject(
 func reachableObjects(
 	commit *object.Commit,
 	seen map[plumbing.Hash]bool,
+	ignore []plumbing.Hash,
 	cb func(h plumbing.Hash)) error {
-	return object.NewCommitPreorderIter(commit).
-		ForEach(func(commit *object.Commit) error {
-			if seen[commit.Hash] {
-				return nil
-			}
 
-			cb(commit.Hash)
+	i := object.NewCommitPreorderIter(commit, ignore)
+	return i.ForEach(func(commit *object.Commit) error {
+		if seen[commit.Hash] {
+			return nil
+		}
+
+		cb(commit.Hash)
 
-			tree, err := commit.Tree()
-			if err != nil {
-				return err
-			}
+		tree, err := commit.Tree()
+		if err != nil {
+			return err
+		}
 
-			return iterateCommitTrees(seen, tree, cb)
-		})
+		return iterateCommitTrees(seen, tree, cb)
+	})
 }
 
 // iterateCommitTrees iterate all reachable trees from the given commit

remote.go

@@ -104,6 +104,7 @@ func (r *Remote) Push(o *PushOptions) (err error) {
 
 	req := packp.NewReferenceUpdateRequestFromCapabilities(ar.Capabilities)
 	if err := r.addReferencesToUpdate(o.RefSpecs, remoteRefs, req); err != nil {
+
 		return err
 	}
 
@@ -121,6 +122,15 @@ func (r *Remote) Push(o *PushOptions) (err error) {
 		return err
 	}
 
+	stop, err := r.s.Shallow()
+	if err != nil {
+		return err
+	}
+
+	// if we have shallow we should include this as part of the objects that
+	// we are aware.
+	haves = append(haves, stop...)
+
 	hashesToPush, err := revlist.Objects(r.s, objects, haves)
 	if err != nil {
 		return err
@@ -486,7 +496,7 @@ func isFastForward(s storer.EncodedObjectStorer, old, new plumbing.Hash) (bool,
 	}
 
 	found := false
-	iter := object.NewCommitPreorderIter(c)
+	iter := object.NewCommitPreorderIter(c, nil)
 	return found, iter.ForEach(func(c *object.Commit) error {
 		if c.Hash != old {
 			return nil

repository.go

@@ -689,7 +689,7 @@ func (r *Repository) Log(o *LogOptions) (object.CommitIter, error) {
 		return nil, err
 	}
 
-	return object.NewCommitPreorderIter(commit), nil
+	return object.NewCommitPreorderIter(commit, nil), nil
 }
 
 // Tags returns all the References from Tags. This method returns all the tag
@@ -918,7 +918,7 @@ func (r *Repository) ResolveRevision(rev plumbing.Revision) (*plumbing.Hash, err
 				commit = c
 			}
 		case revision.CaretReg:
-			history := object.NewCommitPreorderIter(commit)
+			history := object.NewCommitPreorderIter(commit, nil)
 
 			re := item.(revision.CaretReg).Regexp
 			negate := item.(revision.CaretReg).Negate
@@ -948,7 +948,7 @@ func (r *Repository) ResolveRevision(rev plumbing.Revision) (*plumbing.Hash, err
 
 			commit = c
 		case revision.AtDate:
-			history := object.NewCommitPreorderIter(commit)
+			history := object.NewCommitPreorderIter(commit, nil)
 
 			date := item.(revision.AtDate).Date
 

repository_test.go

@@ -20,6 +20,7 @@ import (
 	. "gopkg.in/check.v1"
 	"gopkg.in/src-d/go-billy.v3/memfs"
 	"gopkg.in/src-d/go-billy.v3/osfs"
+	"gopkg.in/src-d/go-billy.v3/util"
 )
 
 type RepositorySuite struct {
@@ -767,6 +768,50 @@ func (s *RepositorySuite) TestPushToEmptyRepository(c *C) {
 	c.Assert(err, IsNil)
 }
 
+func (s *RepositorySuite) TestPushDepth(c *C) {
+	dir, err := ioutil.TempDir("", "push-depth")
+	defer os.RemoveAll(dir)
+
+	origin, err := PlainClone(c.MkDir(), true, &CloneOptions{
+		URL: fixtures.Basic().One().DotGit().Root(),
+	})
+
+	c.Assert(err, IsNil)
+	fs := origin.Storer.(*filesystem.Storage).Filesystem()
+
+	r, err := Clone(memory.NewStorage(), memfs.New(), &CloneOptions{
+		URL:   fs.Root(),
+		Depth: 1,
+	})
+	c.Assert(err, IsNil)
+
+	err = util.WriteFile(r.wt, "foo", nil, 0755)
+	c.Assert(err, IsNil)
+
+	w, err := r.Worktree()
+	c.Assert(err, IsNil)
+
+	_, err = w.Add("foo")
+	c.Assert(err, IsNil)
+
+	hash, err := w.Commit("foo", &CommitOptions{
+		Author:    defaultSignature(),
+		Committer: defaultSignature(),
+	})
+	c.Assert(err, IsNil)
+
+	err = r.Push(&PushOptions{})
+	c.Assert(err, IsNil)
+
+	remote, err := origin.Head()
+	c.Assert(err, IsNil)
+	c.Assert(remote.Hash(), Equals, hash)
+
+	local, err := r.Head()
+	c.Assert(err, IsNil)
+	c.Assert(local.Hash(), Equals, remote.Hash())
+}
+
 func (s *RepositorySuite) TestPushNonExistentRemote(c *C) {
 	srcFs := fixtures.Basic().One().DotGit()
 	sto, err := filesystem.NewStorage(srcFs)