pkg/vcs: extend ListCommitHashes

pkg/email/lore/read.go

@@ -5,6 +5,7 @@ package lore
 
 import (
 	"fmt"
+	"time"
 
 	"github.com/google/syzkaller/pkg/vcs"
 )
@@ -16,7 +17,7 @@ type EmailReader struct {
 // ReadArchive queries the parsed messages from a single LKML message archive.
 func ReadArchive(dir string, messages chan<- *EmailReader) error {
 	repo := vcs.NewLKMLRepo(dir)
-	commits, err := repo.ListCommitHashes("HEAD")
+	commits, err := repo.ListCommitHashes("HEAD", time.Time{})
 	if err != nil {
 		return fmt.Errorf("failed to get recent commits: %w", err)
 	}

pkg/vcs/fuchsia.go

@@ -7,6 +7,7 @@ import (
 	"fmt"
 	"os"
 	"path/filepath"
+	"time"
 
 	"github.com/google/syzkaller/pkg/osutil"
 )
@@ -105,8 +106,8 @@ func (ctx *fuchsia) Contains(commit string) (bool, error) {
 	return ctx.repo.Contains(commit)
 }
 
-func (ctx *fuchsia) ListCommitHashes(base string) ([]string, error) {
-	return ctx.repo.ListCommitHashes(base)
+func (ctx *fuchsia) ListCommitHashes(baseCommit string, from time.Time) ([]string, error) {
+	return ctx.repo.ListCommitHashes(baseCommit, from)
 }
 
 func (ctx *fuchsia) Object(name, commit string) ([]byte, error) {

pkg/vcs/git.go

@@ -381,11 +381,18 @@ func (git *git) GetCommitsByTitles(titles []string) ([]*Commit, []string, error)
 	return results, missing, nil
 }
 
-func (git *git) ListCommitHashes(baseCommit string) ([]string, error) {
-	output, err := git.git("log", "--pretty=format:%h", baseCommit)
+func (git *git) ListCommitHashes(baseCommit string, from time.Time) ([]string, error) {
+	args := []string{"log", "--pretty=format:%h"}
+	if !from.IsZero() {
+		args = append(args, "--since", from.Format(time.RFC3339))
+	}
+	output, err := git.git(append(args, baseCommit)...)
 	if err != nil {
 		return nil, err
 	}
+	if len(output) == 0 {
+		return nil, nil
+	}
 	return strings.Split(string(output), "\n"), nil
 }
 

pkg/vcs/git_test.go

@@ -248,7 +248,7 @@ func TestCommitHashes(t *testing.T) {
 	repo.Git("commit", "--no-edit", "--allow-empty", "-m", "target")
 	repo.Git("checkout", "-b", "branch-b")
 	repo.Git("commit", "--no-edit", "--allow-empty", "-m", "target")
-	got, err := repo.repo.ListCommitHashes("HEAD")
+	got, err := repo.repo.ListCommitHashes("HEAD", time.Time{})
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -263,7 +263,7 @@ func TestCommitHashes(t *testing.T) {
 
 	// Now change HEAD.
 	repo.Git("checkout", "branch-a")
-	got, err = repo.repo.ListCommitHashes("HEAD")
+	got, err = repo.repo.ListCommitHashes("HEAD", time.Time{})
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -293,7 +293,7 @@ func TestObject(t *testing.T) {
 	repo.Git("add", "object.txt")
 	repo.Git("commit", "--no-edit", "--allow-empty", "-m", "target")
 
-	commits, err := repo.repo.ListCommitHashes("HEAD")
+	commits, err := repo.repo.ListCommitHashes("HEAD", time.Time{})
 	if err != nil {
 		t.Fatal(err)
 	}

pkg/vcs/vcs.go

@@ -63,7 +63,7 @@ type Repo interface {
 	Contains(commit string) (bool, error)
 
 	// ListCommitHashes lists all commit hashes reachable from baseCommit.
-	ListCommitHashes(baseCommit string) ([]string, error)
+	ListCommitHashes(baseCommit string, from time.Time) ([]string, error)
 
 	// Object returns the contents of a git repository object at the particular moment in history.
 	Object(name, commit string) ([]byte, error)