feat(dir2config): defaults

vendor/gopkg.in/src-d/go-git.v4/plumbing/revlist/revlist.go

@@ -0,0 +1,230 @@
+// Package revlist provides support to access the ancestors of commits, in a
+// similar way as the git-rev-list command.
+package revlist
+
+import (
+	"fmt"
+	"io"
+
+	"gopkg.in/src-d/go-git.v4/plumbing"
+	"gopkg.in/src-d/go-git.v4/plumbing/filemode"
+	"gopkg.in/src-d/go-git.v4/plumbing/object"
+	"gopkg.in/src-d/go-git.v4/plumbing/storer"
+)
+
+// Objects applies a complementary set. It gets all the hashes from all
+// 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,
+	objs,
+	ignore []plumbing.Hash,
+) ([]plumbing.Hash, error) {
+	return ObjectsWithStorageForIgnores(s, s, objs, ignore)
+}
+
+// ObjectsWithStorageForIgnores is the same as Objects, but a
+// secondary storage layer can be provided, to be used to finding the
+// full set of objects to be ignored while finding the reachable
+// objects.  This is useful when the main `s` storage layer is slow
+// and/or remote, while the ignore list is available somewhere local.
+func ObjectsWithStorageForIgnores(
+	s, ignoreStore storer.EncodedObjectStorer,
+	objs,
+	ignore []plumbing.Hash,
+) ([]plumbing.Hash, error) {
+	ignore, err := objects(ignoreStore, ignore, nil, true)
+	if err != nil {
+		return nil, err
+	}
+
+	return objects(s, objs, ignore, false)
+}
+
+func objects(
+	s storer.EncodedObjectStorer,
+	objects,
+	ignore []plumbing.Hash,
+	allowMissingObjects bool,
+) ([]plumbing.Hash, error) {
+	seen := hashListToSet(ignore)
+	result := make(map[plumbing.Hash]bool)
+	visited := make(map[plumbing.Hash]bool)
+
+	walkerFunc := func(h plumbing.Hash) {
+		if !seen[h] {
+			result[h] = true
+			seen[h] = true
+		}
+	}
+
+	for _, h := range objects {
+		if err := processObject(s, h, seen, visited, ignore, walkerFunc); err != nil {
+			if allowMissingObjects && err == plumbing.ErrObjectNotFound {
+				continue
+			}
+
+			return nil, err
+		}
+	}
+
+	return hashSetToList(result), nil
+}
+
+// processObject obtains the object using the hash an process it depending of its type
+func processObject(
+	s storer.EncodedObjectStorer,
+	h plumbing.Hash,
+	seen map[plumbing.Hash]bool,
+	visited map[plumbing.Hash]bool,
+	ignore []plumbing.Hash,
+	walkerFunc func(h plumbing.Hash),
+) error {
+	if seen[h] {
+		return nil
+	}
+
+	o, err := s.EncodedObject(plumbing.AnyObject, h)
+	if err != nil {
+		return err
+	}
+
+	do, err := object.DecodeObject(s, o)
+	if err != nil {
+		return err
+	}
+
+	switch do := do.(type) {
+	case *object.Commit:
+		return reachableObjects(do, seen, visited, ignore, walkerFunc)
+	case *object.Tree:
+		return iterateCommitTrees(seen, do, walkerFunc)
+	case *object.Tag:
+		walkerFunc(do.Hash)
+		return processObject(s, do.Target, seen, visited, ignore, walkerFunc)
+	case *object.Blob:
+		walkerFunc(do.Hash)
+	default:
+		return fmt.Errorf("object type not valid: %s. "+
+			"Object reference: %s", o.Type(), o.Hash())
+	}
+
+	return nil
+}
+
+// reachableObjects returns, using the callback function, all the reachable
+// objects from the specified commit. To avoid to iterate over seen commits,
+// if a commit hash is into the 'seen' set, we will not iterate all his trees
+// and blobs objects.
+func reachableObjects(
+	commit *object.Commit,
+	seen map[plumbing.Hash]bool,
+	visited map[plumbing.Hash]bool,
+	ignore []plumbing.Hash,
+	cb func(h plumbing.Hash),
+) error {
+	i := object.NewCommitPreorderIter(commit, seen, ignore)
+	pending := make(map[plumbing.Hash]bool)
+	addPendingParents(pending, visited, commit)
+	for {
+		commit, err := i.Next()
+		if err == io.EOF {
+			break
+		}
+
+		if err != nil {
+			return err
+		}
+
+		if pending[commit.Hash] {
+			delete(pending, commit.Hash)
+		}
+
+		addPendingParents(pending, visited, commit)
+
+		if visited[commit.Hash] && len(pending) == 0 {
+			break
+		}
+
+		if seen[commit.Hash] {
+			continue
+		}
+
+		cb(commit.Hash)
+
+		tree, err := commit.Tree()
+		if err != nil {
+			return err
+		}
+
+		if err := iterateCommitTrees(seen, tree, cb); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func addPendingParents(pending, visited map[plumbing.Hash]bool, commit *object.Commit) {
+	for _, p := range commit.ParentHashes {
+		if !visited[p] {
+			pending[p] = true
+		}
+	}
+}
+
+// iterateCommitTrees iterate all reachable trees from the given commit
+func iterateCommitTrees(
+	seen map[plumbing.Hash]bool,
+	tree *object.Tree,
+	cb func(h plumbing.Hash),
+) error {
+	if seen[tree.Hash] {
+		return nil
+	}
+
+	cb(tree.Hash)
+
+	treeWalker := object.NewTreeWalker(tree, true, seen)
+
+	for {
+		_, e, err := treeWalker.Next()
+		if err == io.EOF {
+			break
+		}
+		if err != nil {
+			return err
+		}
+
+		if e.Mode == filemode.Submodule {
+			continue
+		}
+
+		if seen[e.Hash] {
+			continue
+		}
+
+		cb(e.Hash)
+	}
+
+	return nil
+}
+
+func hashSetToList(hashes map[plumbing.Hash]bool) []plumbing.Hash {
+	var result []plumbing.Hash
+	for key := range hashes {
+		result = append(result, key)
+	}
+
+	return result
+}
+
+func hashListToSet(hashes []plumbing.Hash) map[plumbing.Hash]bool {
+	result := make(map[plumbing.Hash]bool)
+	for _, h := range hashes {
+		result[h] = true
+	}
+
+	return result
+}