perf: improve the way we check if refs are not pointing to commits

commits.go

@@ -229,46 +229,50 @@ func (i *commitIter) loadNextRef() (err error) {
 			return err
 		}
 
-		ignored, err := isIgnoredReference(i.repo.Repository, i.ref)
-		if err != nil {
-			if i.skipGitErrors {
-				continue
-			}
-
-			return err
-		}
-
-		if ignored {
+		if isIgnoredReference(i.ref) {
 			continue
 		}
 
-		i.queue = append(i.queue, i.ref.Hash())
-
 		return nil
 	}
 }
 
 func (i *commitIter) Next() (*object.Commit, error) {
 	for {
+		var commit *object.Commit
+		var err error
+
 		if i.ref == nil {
 			if err := i.loadNextRef(); err != nil {
 				return nil, err
 			}
-		}
 
-		if len(i.queue) == 0 {
-			i.ref = nil
-			continue
-		}
+			if _, ok := i.seen[i.ref.Hash()]; ok {
+				continue
+			}
+			i.seen[i.ref.Hash()] = struct{}{}
 
-		hash := i.queue[0]
-		i.queue = i.queue[1:]
-		if _, ok := i.seen[hash]; ok {
-			continue
+			commit, err = resolveCommit(i.repo, i.ref.Hash())
+			if errInvalidCommit.Is(err) {
+				i.ref = nil
+				continue
+			}
+		} else {
+			if len(i.queue) == 0 {
+				i.ref = nil
+				continue
+			}
+
+			hash := i.queue[0]
+			i.queue = i.queue[1:]
+			if _, ok := i.seen[hash]; ok {
+				continue
+			}
+			i.seen[hash] = struct{}{}
+
+			commit, err = i.repo.CommitObject(hash)
 		}
-		i.seen[hash] = struct{}{}
 
-		commit, err := i.repo.CommitObject(hash)
 		if err != nil {
 			if i.skipGitErrors {
 				continue

integration_test.go

@@ -594,7 +594,7 @@ func TestMissingHeadRefs(t *testing.T) {
 
 	rows, err := sql.RowIterToRows(iter)
 	require.NoError(err)
-	require.Len(rows, 54)
+	require.Len(rows, 56)
 }
 
 func BenchmarkQueries(b *testing.B) {

ref_commits.go

@@ -305,32 +305,19 @@ func (i *refCommitsRowIter) next() (sql.Row, error) {
 					i.repo.Close()
 					return nil, err
 				}
-
-				ignored, err := isIgnoredReference(i.repo.Repository, ref)
-				if err != nil {
-					if i.skipGitErrors {
-						continue
-					}
-
-					return nil, err
-				}
-
-				if ignored {
-					continue
-				}
 			} else {
 				ref = plumbing.NewHashReference(plumbing.ReferenceName("HEAD"), i.head.Hash())
 				i.head = nil
 			}
 
 			i.ref = ref
-			if !i.shouldVisitRef(ref) {
+			if !i.shouldVisitRef(ref) || isIgnoredReference(ref) {
 				continue
 			}
 
 			commit, err := resolveCommit(i.repo, ref.Hash())
 			if err != nil {
-				if i.skipGitErrors {
+				if errInvalidCommit.Is(err) || i.skipGitErrors {
 					continue
 				}
 

references.go

@@ -6,7 +6,6 @@ import (
 	"io"
 	"strings"
 
-	git "gopkg.in/src-d/go-git.v4"
 	"gopkg.in/src-d/go-mysql-server.v0/sql"
 
 	"gopkg.in/src-d/go-git.v4/plumbing"
@@ -300,16 +299,7 @@ func (i *refRowIter) next() (sql.Row, error) {
 			return nil, err
 		}
 
-		ignored, err := isIgnoredReference(i.repo.Repository, o)
-		if err != nil {
-			if i.skipGitErrors {
-				continue
-			}
-
-			return nil, err
-		}
-
-		if ignored {
+		if isIgnoredReference(o) {
 			continue
 		}
 
@@ -351,15 +341,6 @@ func referenceToRow(repositoryID string, c *plumbing.Reference) sql.Row {
 	)
 }
 
-func isIgnoredReference(repo *git.Repository, ref *plumbing.Reference) (bool, error) {
-	if ref.Type() != plumbing.HashReference {
-		return true, nil
-	}
-
-	obj, err := repo.Object(plumbing.AnyObject, ref.Hash())
-	if err != nil {
-		return false, err
-	}
-
-	return obj.Type() != plumbing.CommitObject, nil
+func isIgnoredReference(r *plumbing.Reference) bool {
+	return r.Type() != plumbing.HashReference
 }

squash_iterator.go

@@ -489,16 +489,7 @@ func (i *squashRefIter) Advance() error {
 			}
 		}
 
-		ignored, err := isIgnoredReference(i.repo.Repository, ref)
-		if err != nil {
-			if i.skipGitErrors {
-				continue
-			}
-
-			return err
-		}
-
-		if ignored {
+		if isIgnoredReference(ref) {
 			continue
 		}
 
@@ -743,16 +734,7 @@ func (i *squashRepoRefsIter) Advance() error {
 			}
 		}
 
-		ignored, err := isIgnoredReference(i.repos.Repository().Repository, ref)
-		if err != nil {
-			if i.skipGitErrors {
-				continue
-			}
-
-			return err
-		}
-
-		if ignored {
+		if isIgnoredReference(ref) {
 			continue
 		}
 
@@ -890,16 +872,7 @@ func (i *squashRemoteRefsIter) Advance() error {
 			}
 		}
 
-		ignored, err := isIgnoredReference(i.Repository().Repository, ref)
-		if err != nil {
-			if i.skipGitErrors {
-				continue
-			}
-
-			return err
-		}
-
-		if ignored {
+		if isIgnoredReference(ref) {
 			continue
 		}
 
@@ -1010,7 +983,7 @@ func (i *squashRefRefCommitsIter) Advance() error {
 					"error": err,
 				}).Error("unable to get commit")
 
-				if i.skipGitErrors {
+				if errInvalidCommit.Is(err) || i.skipGitErrors {
 					continue
 				}
 
@@ -1116,7 +1089,7 @@ func (i *squashRefHeadRefCommitsIter) Advance() error {
 				"error": err,
 			}).Error("unable to get commit")
 
-			if i.skipGitErrors {
+			if errInvalidCommit.Is(err) || i.skipGitErrors {
 				continue
 			}