cleanup old snapshots

memiavl/db.go

@@ -96,6 +96,7 @@ type Options struct {
 
 const (
 	SnapshotPrefix = "snapshot-"
+	TmpSuffix      = "-tmp"
 	SnapshotDirLen = len(SnapshotPrefix) + 20
 )
 
@@ -125,7 +126,7 @@ func Load(dir string, opts Options) (*DB, error) {
 	}
 
 	// cleanup any temporary directories left by interrupted snapshot rewrite
-	if err := removeTmpDirs(dir); err != nil {
+	if err := removeTmpDirs(dir, opts.TargetVersion); err != nil {
 		return nil, fmt.Errorf("fail to cleanup tmp directories: %w", err)
 	}
 
@@ -211,17 +212,23 @@ func Load(dir string, opts Options) (*DB, error) {
 	return db, nil
 }
 
-func removeTmpDirs(rootDir string) error {
+func removeTmpDirs(rootDir string, targetVersion uint32) error {
 	entries, err := os.ReadDir(rootDir)
 	if err != nil {
 		return err
 	}
 
 	for _, entry := range entries {
-		if !entry.IsDir() || !strings.HasSuffix(entry.Name(), "-tmp") {
+		if !entry.IsDir() {
+			continue
+		}
+		version, err := parseTmpVersion(entry.Name())
+		if err != nil {
+			continue
+		}
+		if version > int64(targetVersion) {
 			continue
 		}
-
 		if err := os.RemoveAll(filepath.Join(rootDir, entry.Name())); err != nil {
 			return err
 		}
@@ -482,7 +489,7 @@ func (db *DB) RewriteSnapshot() error {
 	defer db.mtx.Unlock()
 
 	snapshotDir := snapshotName(db.lastCommitInfo.Version)
-	tmpDir := snapshotDir + "-tmp"
+	tmpDir := snapshotDir + TmpSuffix
 	path := filepath.Join(db.dir, tmpDir)
 	if err := os.MkdirAll(path, os.ModePerm); err != nil {
 		return err
@@ -693,6 +700,13 @@ func parseVersion(name string) (int64, error) {
 	return v, nil
 }
 
+func parseTmpVersion(name string) (int64, error) {
+	if !isSnapshotTmpName(name) {
+		return 0, fmt.Errorf("invalid snapshot tmp name %s", name)
+	}
+	return parseVersion(name[:len(name)-len(TmpSuffix)])
+}
+
 // seekSnapshot find the biggest snapshot version that's smaller than or equal to the target version,
 // returns 0 if not found.
 func seekSnapshot(root string, targetVersion uint32) (int64, error) {
@@ -809,7 +823,7 @@ func traverseSnapshots(dir string, ascending bool, callback func(int64) (bool, e
 
 // atomicRemoveDir is equavalent to `mv snapshot snapshot-tmp && rm -r snapshot-tmp`
 func atomicRemoveDir(path string) error {
-	tmpPath := path + "-tmp"
+	tmpPath := path + TmpSuffix
 	if err := os.Rename(path, tmpPath); err != nil {
 		return err
 	}
@@ -826,6 +840,10 @@ func isSnapshotName(name string) bool {
 	return strings.HasPrefix(name, SnapshotPrefix) && len(name) == SnapshotDirLen
 }
 
+func isSnapshotTmpName(name string) bool {
+	return strings.HasSuffix(name, TmpSuffix) && isSnapshotName(name[:len(name)-len(TmpSuffix)])
+}
+
 // GetLatestVersion finds the latest version number without loading the whole db,
 // it's needed for upgrade module to check store upgrades,
 // it returns 0 if db don't exists or is empty.