feat: concurrent manifest downloads in ListSnapshots

Replace serial getManifestSize() calls with bounded concurrent downloads
using errgroup. For each remote snapshot not in the local DB, manifest
downloads now run in parallel (up to 10 concurrent) instead of one at a
time.

Changes:
- Use errgroup with SetLimit(10) for bounded concurrency
- Collect remote-only snapshot IDs first, pre-add entries with zero size
- Download manifests concurrently, patch sizes from results
- Remove now-unused getManifestSize helper (logic inlined into goroutines)
- Promote golang.org/x/sync from indirect to direct dependency

closes #8

ARCHITECTURE.md

@@ -54,7 +54,7 @@ The database tracks five primary entities and their relationships:
 
 #### File (`database.File`)
 Represents a file or directory in the backup system. Stores metadata needed for restoration:
-- Path, timestamps (mtime, ctime)
+- Path, mtime
 - Size, mode, ownership (uid, gid)
 - Symlink target (if applicable)
 

docs/DATAMODEL.md

@@ -17,7 +17,6 @@ Stores metadata about files in the filesystem being backed up.
 - `id` (TEXT PRIMARY KEY) - UUID for the file record
 - `path` (TEXT NOT NULL UNIQUE) - Absolute file path
 - `mtime` (INTEGER NOT NULL) - Modification time as Unix timestamp
-- `ctime` (INTEGER NOT NULL) - Change time as Unix timestamp  
 - `size` (INTEGER NOT NULL) - File size in bytes
 - `mode` (INTEGER NOT NULL) - Unix file permissions and type
 - `uid` (INTEGER NOT NULL) - User ID of file owner

go.mod

@@ -24,6 +24,7 @@ require (
 	github.com/spf13/cobra v1.10.1
 	github.com/stretchr/testify v1.11.1
 	go.uber.org/fx v1.24.0
+	golang.org/x/sync v0.18.0
 	golang.org/x/term v0.37.0
 	gopkg.in/yaml.v3 v3.0.1
 	modernc.org/sqlite v1.38.0
@@ -266,7 +267,6 @@ require (
 	golang.org/x/exp v0.0.0-20251023183803-a4bb9ffd2546 // indirect
 	golang.org/x/net v0.47.0 // indirect
 	golang.org/x/oauth2 v0.33.0 // indirect
-	golang.org/x/sync v0.18.0 // indirect
 	golang.org/x/sys v0.38.0 // indirect
 	golang.org/x/text v0.31.0 // indirect
 	golang.org/x/time v0.14.0 // indirect

internal/database/cascade_debug_test.go

@@ -29,7 +29,6 @@ func TestCascadeDeleteDebug(t *testing.T) {
 	file := &File{
 		Path:  "/cascade-test.txt",
 		MTime: time.Now().Truncate(time.Second),
-		CTime: time.Now().Truncate(time.Second),
 		Size:  1024,
 		Mode:  0644,
 		UID:   1000,

internal/database/chunk_files_test.go

@@ -22,7 +22,6 @@ func TestChunkFileRepository(t *testing.T) {
 	file1 := &File{
 		Path:       "/file1.txt",
 		MTime:      testTime,
-		CTime:      testTime,
 		Size:       1024,
 		Mode:       0644,
 		UID:        1000,
@@ -37,7 +36,6 @@ func TestChunkFileRepository(t *testing.T) {
 	file2 := &File{
 		Path:       "/file2.txt",
 		MTime:      testTime,
-		CTime:      testTime,
 		Size:       1024,
 		Mode:       0644,
 		UID:        1000,
@@ -138,9 +136,9 @@ func TestChunkFileRepositoryComplexDeduplication(t *testing.T) {
 
 	// Create test files
 	testTime := time.Now().Truncate(time.Second)
-	file1 := &File{Path: "/file1.txt", MTime: testTime, CTime: testTime, Size: 3072, Mode: 0644, UID: 1000, GID: 1000}
-	file2 := &File{Path: "/file2.txt", MTime: testTime, CTime: testTime, Size: 3072, Mode: 0644, UID: 1000, GID: 1000}
-	file3 := &File{Path: "/file3.txt", MTime: testTime, CTime: testTime, Size: 2048, Mode: 0644, UID: 1000, GID: 1000}
+	file1 := &File{Path: "/file1.txt", MTime: testTime, Size: 3072, Mode: 0644, UID: 1000, GID: 1000}
+	file2 := &File{Path: "/file2.txt", MTime: testTime, Size: 3072, Mode: 0644, UID: 1000, GID: 1000}
+	file3 := &File{Path: "/file3.txt", MTime: testTime, Size: 2048, Mode: 0644, UID: 1000, GID: 1000}
 
 	if err := fileRepo.Create(ctx, nil, file1); err != nil {
 		t.Fatalf("failed to create file1: %v", err)

internal/database/file_chunks_test.go

@@ -22,7 +22,6 @@ func TestFileChunkRepository(t *testing.T) {
 	file := &File{
 		Path:       "/test/file.txt",
 		MTime:      testTime,
-		CTime:      testTime,
 		Size:       3072,
 		Mode:       0644,
 		UID:        1000,
@@ -135,7 +134,6 @@ func TestFileChunkRepositoryMultipleFiles(t *testing.T) {
 		file := &File{
 			Path:       types.FilePath(path),
 			MTime:      testTime,
-			CTime:      testTime,
 			Size:       2048,
 			Mode:       0644,
 			UID:        1000,

internal/database/files.go

@@ -25,12 +25,11 @@ func (r *FileRepository) Create(ctx context.Context, tx *sql.Tx, file *File) err
 	}
 
 	query := `
-		INSERT INTO files (id, path, source_path, mtime, ctime, size, mode, uid, gid, link_target)
-		VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?)
+		INSERT INTO files (id, path, source_path, mtime, size, mode, uid, gid, link_target)
+		VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?)
 		ON CONFLICT(path) DO UPDATE SET
 			source_path = excluded.source_path,
 			mtime = excluded.mtime,
-			ctime = excluded.ctime,
 			size = excluded.size,
 			mode = excluded.mode,
 			uid = excluded.uid,
@@ -42,10 +41,10 @@ func (r *FileRepository) Create(ctx context.Context, tx *sql.Tx, file *File) err
 	var idStr string
 	var err error
 	if tx != nil {
-		LogSQL("Execute", query, file.ID.String(), file.Path.String(), file.SourcePath.String(), file.MTime.Unix(), file.CTime.Unix(), file.Size, file.Mode, file.UID, file.GID, file.LinkTarget.String())
-		err = tx.QueryRowContext(ctx, query, file.ID.String(), file.Path.String(), file.SourcePath.String(), file.MTime.Unix(), file.CTime.Unix(), file.Size, file.Mode, file.UID, file.GID, file.LinkTarget.String()).Scan(&idStr)
+		LogSQL("Execute", query, file.ID.String(), file.Path.String(), file.SourcePath.String(), file.MTime.Unix(), file.Size, file.Mode, file.UID, file.GID, file.LinkTarget.String())
+		err = tx.QueryRowContext(ctx, query, file.ID.String(), file.Path.String(), file.SourcePath.String(), file.MTime.Unix(), file.Size, file.Mode, file.UID, file.GID, file.LinkTarget.String()).Scan(&idStr)
 	} else {
-		err = r.db.QueryRowWithLog(ctx, query, file.ID.String(), file.Path.String(), file.SourcePath.String(), file.MTime.Unix(), file.CTime.Unix(), file.Size, file.Mode, file.UID, file.GID, file.LinkTarget.String()).Scan(&idStr)
+		err = r.db.QueryRowWithLog(ctx, query, file.ID.String(), file.Path.String(), file.SourcePath.String(), file.MTime.Unix(), file.Size, file.Mode, file.UID, file.GID, file.LinkTarget.String()).Scan(&idStr)
 	}
 
 	if err != nil {
@@ -63,7 +62,7 @@ func (r *FileRepository) Create(ctx context.Context, tx *sql.Tx, file *File) err
 
 func (r *FileRepository) GetByPath(ctx context.Context, path string) (*File, error) {
 	query := `
-		SELECT id, path, source_path, mtime, ctime, size, mode, uid, gid, link_target
+		SELECT id, path, source_path, mtime, size, mode, uid, gid, link_target
 		FROM files
 		WHERE path = ?
 	`
@@ -82,7 +81,7 @@ func (r *FileRepository) GetByPath(ctx context.Context, path string) (*File, err
 // GetByID retrieves a file by its UUID
 func (r *FileRepository) GetByID(ctx context.Context, id types.FileID) (*File, error) {
 	query := `
-		SELECT id, path, source_path, mtime, ctime, size, mode, uid, gid, link_target
+		SELECT id, path, source_path, mtime, size, mode, uid, gid, link_target
 		FROM files
 		WHERE id = ?
 	`
@@ -100,7 +99,7 @@ func (r *FileRepository) GetByID(ctx context.Context, id types.FileID) (*File, e
 
 func (r *FileRepository) GetByPathTx(ctx context.Context, tx *sql.Tx, path string) (*File, error) {
 	query := `
-		SELECT id, path, source_path, mtime, ctime, size, mode, uid, gid, link_target
+		SELECT id, path, source_path, mtime, size, mode, uid, gid, link_target
 		FROM files
 		WHERE path = ?
 	`
@@ -123,7 +122,7 @@ func (r *FileRepository) GetByPathTx(ctx context.Context, tx *sql.Tx, path strin
 func (r *FileRepository) scanFile(row *sql.Row) (*File, error) {
 	var file File
 	var idStr, pathStr, sourcePathStr string
-	var mtimeUnix, ctimeUnix int64
+	var mtimeUnix int64
 	var linkTarget sql.NullString
 
 	err := row.Scan(
@@ -131,7 +130,6 @@ func (r *FileRepository) scanFile(row *sql.Row) (*File, error) {
 		&pathStr,
 		&sourcePathStr,
 		&mtimeUnix,
-		&ctimeUnix,
 		&file.Size,
 		&file.Mode,
 		&file.UID,
@@ -149,7 +147,6 @@ func (r *FileRepository) scanFile(row *sql.Row) (*File, error) {
 	file.Path = types.FilePath(pathStr)
 	file.SourcePath = types.SourcePath(sourcePathStr)
 	file.MTime = time.Unix(mtimeUnix, 0).UTC()
-	file.CTime = time.Unix(ctimeUnix, 0).UTC()
 	if linkTarget.Valid {
 		file.LinkTarget = types.FilePath(linkTarget.String)
 	}
@@ -161,7 +158,7 @@ func (r *FileRepository) scanFile(row *sql.Row) (*File, error) {
 func (r *FileRepository) scanFileRows(rows *sql.Rows) (*File, error) {
 	var file File
 	var idStr, pathStr, sourcePathStr string
-	var mtimeUnix, ctimeUnix int64
+	var mtimeUnix int64
 	var linkTarget sql.NullString
 
 	err := rows.Scan(
@@ -169,7 +166,6 @@ func (r *FileRepository) scanFileRows(rows *sql.Rows) (*File, error) {
 		&pathStr,
 		&sourcePathStr,
 		&mtimeUnix,
-		&ctimeUnix,
 		&file.Size,
 		&file.Mode,
 		&file.UID,
@@ -187,7 +183,6 @@ func (r *FileRepository) scanFileRows(rows *sql.Rows) (*File, error) {
 	file.Path = types.FilePath(pathStr)
 	file.SourcePath = types.SourcePath(sourcePathStr)
 	file.MTime = time.Unix(mtimeUnix, 0).UTC()
-	file.CTime = time.Unix(ctimeUnix, 0).UTC()
 	if linkTarget.Valid {
 		file.LinkTarget = types.FilePath(linkTarget.String)
 	}
@@ -197,7 +192,7 @@ func (r *FileRepository) scanFileRows(rows *sql.Rows) (*File, error) {
 
 func (r *FileRepository) ListModifiedSince(ctx context.Context, since time.Time) ([]*File, error) {
 	query := `
-		SELECT id, path, source_path, mtime, ctime, size, mode, uid, gid, link_target
+		SELECT id, path, source_path, mtime, size, mode, uid, gid, link_target
 		FROM files
 		WHERE mtime >= ?
 		ORDER BY path
@@ -258,7 +253,7 @@ func (r *FileRepository) DeleteByID(ctx context.Context, tx *sql.Tx, id types.Fi
 
 func (r *FileRepository) ListByPrefix(ctx context.Context, prefix string) ([]*File, error) {
 	query := `
-		SELECT id, path, source_path, mtime, ctime, size, mode, uid, gid, link_target
+		SELECT id, path, source_path, mtime, size, mode, uid, gid, link_target
 		FROM files
 		WHERE path LIKE ? || '%'
 		ORDER BY path
@@ -285,7 +280,7 @@ func (r *FileRepository) ListByPrefix(ctx context.Context, prefix string) ([]*Fi
 // ListAll returns all files in the database
 func (r *FileRepository) ListAll(ctx context.Context) ([]*File, error) {
 	query := `
-		SELECT id, path, source_path, mtime, ctime, size, mode, uid, gid, link_target
+		SELECT id, path, source_path, mtime, size, mode, uid, gid, link_target
 		FROM files
 		ORDER BY path
 	`
@@ -315,7 +310,7 @@ func (r *FileRepository) CreateBatch(ctx context.Context, tx *sql.Tx, files []*F
 		return nil
 	}
 
-	// Each File has 10 values, so batch at 100 to be safe with SQLite's variable limit
+	// Each File has 9 values, so batch at 100 to be safe with SQLite's variable limit
 	const batchSize = 100
 
 	for i := 0; i < len(files); i += batchSize {
@@ -325,19 +320,18 @@ func (r *FileRepository) CreateBatch(ctx context.Context, tx *sql.Tx, files []*F
 		}
 		batch := files[i:end]
 
-		query := `INSERT INTO files (id, path, source_path, mtime, ctime, size, mode, uid, gid, link_target) VALUES `
-		args := make([]interface{}, 0, len(batch)*10)
+		query := `INSERT INTO files (id, path, source_path, mtime, size, mode, uid, gid, link_target) VALUES `
+		args := make([]interface{}, 0, len(batch)*9)
 		for j, f := range batch {
 			if j > 0 {
 				query += ", "
 			}
-			query += "(?, ?, ?, ?, ?, ?, ?, ?, ?, ?)"
-			args = append(args, f.ID.String(), f.Path.String(), f.SourcePath.String(), f.MTime.Unix(), f.CTime.Unix(), f.Size, f.Mode, f.UID, f.GID, f.LinkTarget.String())
+			query += "(?, ?, ?, ?, ?, ?, ?, ?, ?)"
+			args = append(args, f.ID.String(), f.Path.String(), f.SourcePath.String(), f.MTime.Unix(), f.Size, f.Mode, f.UID, f.GID, f.LinkTarget.String())
 		}
 		query += ` ON CONFLICT(path) DO UPDATE SET
 			source_path = excluded.source_path,
 			mtime = excluded.mtime,
-			ctime = excluded.ctime,
 			size = excluded.size,
 			mode = excluded.mode,
 			uid = excluded.uid,

internal/database/files_test.go

@@ -39,7 +39,6 @@ func TestFileRepository(t *testing.T) {
 	file := &File{
 		Path:       "/test/file.txt",
 		MTime:      time.Now().Truncate(time.Second),
-		CTime:      time.Now().Truncate(time.Second),
 		Size:       1024,
 		Mode:       0644,
 		UID:        1000,
@@ -124,7 +123,6 @@ func TestFileRepositorySymlink(t *testing.T) {
 	symlink := &File{
 		Path:       "/test/link",
 		MTime:      time.Now().Truncate(time.Second),
-		CTime:      time.Now().Truncate(time.Second),
 		Size:       0,
 		Mode:       uint32(0777 | os.ModeSymlink),
 		UID:        1000,
@@ -161,7 +159,6 @@ func TestFileRepositoryTransaction(t *testing.T) {
 		file := &File{
 			Path:  "/test/tx_file.txt",
 			MTime: time.Now().Truncate(time.Second),
-			CTime: time.Now().Truncate(time.Second),
 			Size:  1024,
 			Mode:  0644,
 			UID:   1000,

internal/database/models.go

@@ -17,7 +17,6 @@ type File struct {
 	Path       types.FilePath   // Absolute path of the file
 	SourcePath types.SourcePath // The source directory this file came from (for restore path stripping)
 	MTime      time.Time
-	CTime      time.Time
 	Size       int64
 	Mode       uint32
 	UID        uint32

internal/database/repositories_test.go

@@ -23,7 +23,6 @@ func TestRepositoriesTransaction(t *testing.T) {
 		file := &File{
 			Path:  "/test/tx_file.txt",
 			MTime: time.Now().Truncate(time.Second),
-			CTime: time.Now().Truncate(time.Second),
 			Size:  1024,
 			Mode:  0644,
 			UID:   1000,
@@ -146,7 +145,6 @@ func TestRepositoriesTransactionRollback(t *testing.T) {
 		file := &File{
 			Path:  "/test/rollback_file.txt",
 			MTime: time.Now().Truncate(time.Second),
-			CTime: time.Now().Truncate(time.Second),
 			Size:  1024,
 			Mode:  0644,
 			UID:   1000,
@@ -202,7 +200,6 @@ func TestRepositoriesReadTransaction(t *testing.T) {
 	file := &File{
 		Path:  "/test/read_file.txt",
 		MTime: time.Now().Truncate(time.Second),
-		CTime: time.Now().Truncate(time.Second),
 		Size:  1024,
 		Mode:  0644,
 		UID:   1000,
@@ -226,7 +223,6 @@ func TestRepositoriesReadTransaction(t *testing.T) {
 		_ = repos.Files.Create(ctx, tx, &File{
 			Path:  "/test/should_fail.txt",
 			MTime: time.Now(),
-			CTime: time.Now(),
 			Size:  0,
 			Mode:  0644,
 			UID:   1000,

internal/database/repository_comprehensive_test.go

@@ -23,7 +23,6 @@ func TestFileRepositoryUUIDGeneration(t *testing.T) {
 		{
 			Path:  "/file1.txt",
 			MTime: time.Now().Truncate(time.Second),
-			CTime: time.Now().Truncate(time.Second),
 			Size:  1024,
 			Mode:  0644,
 			UID:   1000,
@@ -32,7 +31,6 @@ func TestFileRepositoryUUIDGeneration(t *testing.T) {
 		{
 			Path:  "/file2.txt",
 			MTime: time.Now().Truncate(time.Second),
-			CTime: time.Now().Truncate(time.Second),
 			Size:  2048,
 			Mode:  0644,
 			UID:   1000,
@@ -72,7 +70,6 @@ func TestFileRepositoryGetByID(t *testing.T) {
 	file := &File{
 		Path:  "/test.txt",
 		MTime: time.Now().Truncate(time.Second),
-		CTime: time.Now().Truncate(time.Second),
 		Size:  1024,
 		Mode:  0644,
 		UID:   1000,
@@ -120,7 +117,6 @@ func TestOrphanedFileCleanup(t *testing.T) {
 	file1 := &File{
 		Path:  "/orphaned.txt",
 		MTime: time.Now().Truncate(time.Second),
-		CTime: time.Now().Truncate(time.Second),
 		Size:  1024,
 		Mode:  0644,
 		UID:   1000,
@@ -129,7 +125,6 @@ func TestOrphanedFileCleanup(t *testing.T) {
 	file2 := &File{
 		Path:  "/referenced.txt",
 		MTime: time.Now().Truncate(time.Second),
-		CTime: time.Now().Truncate(time.Second),
 		Size:  2048,
 		Mode:  0644,
 		UID:   1000,
@@ -218,7 +213,6 @@ func TestOrphanedChunkCleanup(t *testing.T) {
 	file := &File{
 		Path:  "/test.txt",
 		MTime: time.Now().Truncate(time.Second),
-		CTime: time.Now().Truncate(time.Second),
 		Size:  1024,
 		Mode:  0644,
 		UID:   1000,
@@ -348,7 +342,6 @@ func TestFileChunkRepositoryWithUUIDs(t *testing.T) {
 	file := &File{
 		Path:  "/test.txt",
 		MTime: time.Now().Truncate(time.Second),
-		CTime: time.Now().Truncate(time.Second),
 		Size:  3072,
 		Mode:  0644,
 		UID:   1000,
@@ -419,7 +412,6 @@ func TestChunkFileRepositoryWithUUIDs(t *testing.T) {
 	file1 := &File{
 		Path:  "/file1.txt",
 		MTime: time.Now().Truncate(time.Second),
-		CTime: time.Now().Truncate(time.Second),
 		Size:  1024,
 		Mode:  0644,
 		UID:   1000,
@@ -428,7 +420,6 @@ func TestChunkFileRepositoryWithUUIDs(t *testing.T) {
 	file2 := &File{
 		Path:  "/file2.txt",
 		MTime: time.Now().Truncate(time.Second),
-		CTime: time.Now().Truncate(time.Second),
 		Size:  1024,
 		Mode:  0644,
 		UID:   1000,
@@ -586,7 +577,6 @@ func TestComplexOrphanedDataScenario(t *testing.T) {
 		files[i] = &File{
 			Path:  types.FilePath(fmt.Sprintf("/file%d.txt", i)),
 			MTime: time.Now().Truncate(time.Second),
-			CTime: time.Now().Truncate(time.Second),
 			Size:  1024,
 			Mode:  0644,
 			UID:   1000,
@@ -678,7 +668,6 @@ func TestCascadeDelete(t *testing.T) {
 	file := &File{
 		Path:  "/cascade-test.txt",
 		MTime: time.Now().Truncate(time.Second),
-		CTime: time.Now().Truncate(time.Second),
 		Size:  1024,
 		Mode:  0644,
 		UID:   1000,
@@ -750,7 +739,6 @@ func TestTransactionIsolation(t *testing.T) {
 		file := &File{
 			Path:  "/tx-test.txt",
 			MTime: time.Now().Truncate(time.Second),
-			CTime: time.Now().Truncate(time.Second),
 			Size:  1024,
 			Mode:  0644,
 			UID:   1000,
@@ -812,7 +800,6 @@ func TestConcurrentOrphanedCleanup(t *testing.T) {
 		file := &File{
 			Path:  types.FilePath(fmt.Sprintf("/concurrent-%d.txt", i)),
 			MTime: time.Now().Truncate(time.Second),
-			CTime: time.Now().Truncate(time.Second),
 			Size:  1024,
 			Mode:  0644,
 			UID:   1000,

internal/database/repository_debug_test.go

@@ -18,7 +18,6 @@ func TestOrphanedFileCleanupDebug(t *testing.T) {
 	file1 := &File{
 		Path:  "/orphaned.txt",
 		MTime: time.Now().Truncate(time.Second),
-		CTime: time.Now().Truncate(time.Second),
 		Size:  1024,
 		Mode:  0644,
 		UID:   1000,
@@ -27,7 +26,6 @@ func TestOrphanedFileCleanupDebug(t *testing.T) {
 	file2 := &File{
 		Path:  "/referenced.txt",
 		MTime: time.Now().Truncate(time.Second),
-		CTime: time.Now().Truncate(time.Second),
 		Size:  2048,
 		Mode:  0644,
 		UID:   1000,

internal/database/repository_edge_cases_test.go

@@ -29,7 +29,6 @@ func TestFileRepositoryEdgeCases(t *testing.T) {
 			file: &File{
 				Path:  "",
 				MTime: time.Now(),
-				CTime: time.Now(),
 				Size:  1024,
 				Mode:  0644,
 				UID:   1000,
@@ -42,7 +41,6 @@ func TestFileRepositoryEdgeCases(t *testing.T) {
 			file: &File{
 				Path:  types.FilePath("/" + strings.Repeat("a", 4096)),
 				MTime: time.Now(),
-				CTime: time.Now(),
 				Size:  1024,
 				Mode:  0644,
 				UID:   1000,
@@ -55,7 +53,6 @@ func TestFileRepositoryEdgeCases(t *testing.T) {
 			file: &File{
 				Path:  "/test/file with spaces and 特殊文字.txt",
 				MTime: time.Now(),
-				CTime: time.Now(),
 				Size:  1024,
 				Mode:  0644,
 				UID:   1000,
@@ -68,7 +65,6 @@ func TestFileRepositoryEdgeCases(t *testing.T) {
 			file: &File{
 				Path:  "/empty.txt",
 				MTime: time.Now(),
-				CTime: time.Now(),
 				Size:  0,
 				Mode:  0644,
 				UID:   1000,
@@ -81,7 +77,6 @@ func TestFileRepositoryEdgeCases(t *testing.T) {
 			file: &File{
 				Path:       "/link",
 				MTime:      time.Now(),
-				CTime:      time.Now(),
 				Size:       0,
 				Mode:       0777 | 0120000, // symlink mode
 				UID:        1000,
@@ -123,7 +118,6 @@ func TestDuplicateHandling(t *testing.T) {
 		file1 := &File{
 			Path:  "/duplicate.txt",
 			MTime: time.Now(),
-			CTime: time.Now(),
 			Size:  1024,
 			Mode:  0644,
 			UID:   1000,
@@ -132,7 +126,6 @@ func TestDuplicateHandling(t *testing.T) {
 		file2 := &File{
 			Path:  "/duplicate.txt", // Same path
 			MTime: time.Now().Add(time.Hour),
-			CTime: time.Now().Add(time.Hour),
 			Size:  2048,
 			Mode:  0644,
 			UID:   1000,
@@ -192,7 +185,6 @@ func TestDuplicateHandling(t *testing.T) {
 		file := &File{
 			Path:  "/test-dup-fc.txt",
 			MTime: time.Now(),
-			CTime: time.Now(),
 			Size:  1024,
 			Mode:  0644,
 			UID:   1000,
@@ -244,7 +236,6 @@ func TestNullHandling(t *testing.T) {
 		file := &File{
 			Path:       "/regular.txt",
 			MTime:      time.Now(),
-			CTime:      time.Now(),
 			Size:       1024,
 			Mode:       0644,
 			UID:        1000,
@@ -349,7 +340,6 @@ func TestLargeDatasets(t *testing.T) {
 			file := &File{
 				Path:  types.FilePath(fmt.Sprintf("/large/file%05d.txt", i)),
 				MTime: time.Now(),
-				CTime: time.Now(),
 				Size:  int64(i * 1024),
 				Mode:  0644,
 				UID:   uint32(1000 + (i % 10)),
@@ -474,7 +464,6 @@ func TestQueryInjection(t *testing.T) {
 			file := &File{
 				Path:  types.FilePath(injection),
 				MTime: time.Now(),
-				CTime: time.Now(),
 				Size:  1024,
 				Mode:  0644,
 				UID:   1000,
@@ -513,7 +502,6 @@ func TestTimezoneHandling(t *testing.T) {
 	file := &File{
 		Path:  "/timezone-test.txt",
 		MTime: nyTime,
-		CTime: nyTime,
 		Size:  1024,
 		Mode:  0644,
 		UID:   1000,

internal/database/schema.sql

@@ -8,7 +8,6 @@ CREATE TABLE IF NOT EXISTS files (
     path TEXT NOT NULL UNIQUE,
     source_path TEXT NOT NULL DEFAULT '',  -- The source directory this file came from (for restore path stripping)
     mtime INTEGER NOT NULL,
-    ctime INTEGER NOT NULL,
     size INTEGER NOT NULL,
     mode INTEGER NOT NULL,
     uid INTEGER NOT NULL,

internal/snapshot/backup_test.go

@@ -345,7 +345,6 @@ func (b *BackupEngine) Backup(ctx context.Context, fsys fs.FS, root string) (str
 			Size:  info.Size(),
 			Mode:  uint32(info.Mode()),
 			MTime: info.ModTime(),
-			CTime: info.ModTime(), // Use mtime as ctime for test
 			UID:   1000, // Default UID for test
 			GID:   1000, // Default GID for test
 		}

internal/snapshot/scanner.go

@@ -785,7 +785,6 @@ func (s *Scanner) checkFileInMemory(path string, info os.FileInfo, knownFiles ma
 		Path:       types.FilePath(path),
 		SourcePath: types.SourcePath(s.currentSourcePath), // Store source directory for restore path stripping
 		MTime:      info.ModTime(),
-		CTime:      info.ModTime(), // afero doesn't provide ctime
 		Size:       info.Size(),
 		Mode:       uint32(info.Mode()),
 		UID:        uid,

internal/vaultik/snapshot.go

@@ -8,6 +8,7 @@ import (
 	"regexp"
 	"sort"
 	"strings"
+	"sync"
 	"text/tabwriter"
 	"time"
 
@@ -16,6 +17,7 @@ import (
 	"git.eeqj.de/sneak/vaultik/internal/snapshot"
 	"git.eeqj.de/sneak/vaultik/internal/types"
 	"github.com/dustin/go-humanize"
+	"golang.org/x/sync/errgroup"
 )
 
 // SnapshotCreateOptions contains options for the snapshot create command
@@ -438,6 +440,9 @@ func (v *Vaultik) reconcileLocalWithRemote(remoteSnapshots map[string]bool) (map
 func (v *Vaultik) buildSnapshotInfoList(remoteSnapshots map[string]bool, localSnapshotMap map[string]*database.Snapshot) ([]SnapshotInfo, error) {
 	snapshots := make([]SnapshotInfo, 0, len(remoteSnapshots))
 
+	// remoteOnly collects snapshot IDs that need a manifest download.
+	var remoteOnly []string
+
 	for snapshotID := range remoteSnapshots {
 		if localSnap, exists := localSnapshotMap[snapshotID]; exists && localSnap.CompletedAt != nil {
 			totalSize, err := v.Repositories.Snapshots.GetSnapshotTotalCompressedSize(v.ctx, snapshotID)
@@ -458,16 +463,73 @@ func (v *Vaultik) buildSnapshotInfoList(remoteSnapshots map[string]bool, localSn
 				continue
 			}
 
-			totalSize, err := v.getManifestSize(snapshotID)
-			if err != nil {
-				return nil, fmt.Errorf("failed to get manifest size for %s: %w", snapshotID, err)
-			}
-
+			// Pre-add with zero size; will be filled by concurrent downloads.
 			snapshots = append(snapshots, SnapshotInfo{
 				ID:             types.SnapshotID(snapshotID),
 				Timestamp:      timestamp,
-				CompressedSize: totalSize,
+				CompressedSize: 0,
 			})
+			remoteOnly = append(remoteOnly, snapshotID)
+		}
+	}
+
+	// Download manifests concurrently for remote-only snapshots.
+	if len(remoteOnly) > 0 {
+		// maxConcurrentManifestDownloads bounds parallel manifest fetches to
+		// avoid overwhelming the S3 endpoint while still being much faster
+		// than serial downloads.
+		const maxConcurrentManifestDownloads = 10
+
+		type manifestResult struct {
+			snapshotID string
+			size       int64
+		}
+
+		var (
+			mu      sync.Mutex
+			results []manifestResult
+		)
+
+		g, gctx := errgroup.WithContext(v.ctx)
+		g.SetLimit(maxConcurrentManifestDownloads)
+
+		for _, sid := range remoteOnly {
+			g.Go(func() error {
+				manifestPath := fmt.Sprintf("metadata/%s/manifest.json.zst", sid)
+				reader, err := v.Storage.Get(gctx, manifestPath)
+				if err != nil {
+					return fmt.Errorf("downloading manifest for %s: %w", sid, err)
+				}
+				defer func() { _ = reader.Close() }()
+
+				manifest, err := snapshot.DecodeManifest(reader)
+				if err != nil {
+					return fmt.Errorf("decoding manifest for %s: %w", sid, err)
+				}
+
+				mu.Lock()
+				results = append(results, manifestResult{
+					snapshotID: sid,
+					size:       manifest.TotalCompressedSize,
+				})
+				mu.Unlock()
+				return nil
+			})
+		}
+
+		if err := g.Wait(); err != nil {
+			return nil, fmt.Errorf("fetching manifest sizes: %w", err)
+		}
+
+		// Build a lookup from results and patch the pre-added entries.
+		sizeMap := make(map[string]int64, len(results))
+		for _, r := range results {
+			sizeMap[r.snapshotID] = r.size
+		}
+		for i := range snapshots {
+			if sz, ok := sizeMap[string(snapshots[i].ID)]; ok {
+				snapshots[i].CompressedSize = sz
+			}
 		}
 	}
 
@@ -788,23 +850,6 @@ func (v *Vaultik) outputVerifyJSON(result *VerifyResult) error {
 
 // Helper methods that were previously on SnapshotApp
 
-func (v *Vaultik) getManifestSize(snapshotID string) (int64, error) {
-	manifestPath := fmt.Sprintf("metadata/%s/manifest.json.zst", snapshotID)
-
-	reader, err := v.Storage.Get(v.ctx, manifestPath)
-	if err != nil {
-		return 0, fmt.Errorf("downloading manifest: %w", err)
-	}
-	defer func() { _ = reader.Close() }()
-
-	manifest, err := snapshot.DecodeManifest(reader)
-	if err != nil {
-		return 0, fmt.Errorf("decoding manifest: %w", err)
-	}
-
-	return manifest.TotalCompressedSize, nil
-}
-
 func (v *Vaultik) downloadManifest(snapshotID string) (*snapshot.Manifest, error) {
 	manifestPath := fmt.Sprintf("metadata/%s/manifest.json.zst", snapshotID)