update snapshot

server/snapshot.go

@@ -28,12 +28,12 @@ type snapshotStore struct {
 }
 
 func snapshotName(t time.Time) string {
-	return fmt.Sprintf("snap-%s.dump", t.Format(snapshotTimeFormat))
+	return fmt.Sprintf("snap-%s.dmp", t.Format(snapshotTimeFormat))
 }
 
 func parseSnapshotName(name string) (time.Time, error) {
 	var timeString string
-	if _, err := fmt.Sscanf(name, "snap-%s.dump", &timeString); err != nil {
+	if _, err := fmt.Sscanf(name, "snap-%s.dmp", &timeString); err != nil {
 		return time.Time{}, err
 	}
 	when, err := time.Parse(snapshotTimeFormat, timeString)
@@ -58,23 +58,10 @@ func newSnapshotStore(cfg *config.Config) (*snapshotStore, error) {
 
 	s.quit = make(chan struct{})
 
-	snapshots, err := ioutil.ReadDir(cfg.Snapshot.Path)
+	if err := s.checkSnapshots(); err != nil {
-	if err != nil {
 		return nil, err
 	}
 
-	for _, info := range snapshots {
-		if _, err := parseSnapshotName(info.Name()); err != nil {
-			log.Error("invalid snapshot file name %s, err: %s", info.Name(), err.Error())
-			continue
-		}
-
-		s.names = append(s.names, info.Name())
-	}
-
-	//from old to new
-	sort.Strings(s.names)
-
 	go s.run()
 
 	return s, nil
@@ -84,15 +71,51 @@ func (s *snapshotStore) Close() {
 	close(s.quit)
 }
 
+func (s *snapshotStore) checkSnapshots() error {
+	cfg := s.cfg
+	snapshots, err := ioutil.ReadDir(cfg.Snapshot.Path)
+	if err != nil {
+		log.Error("read %s error: %s", cfg.Snapshot.Path, err.Error())
+		return err
+	}
+
+	names := []string{}
+	for _, info := range snapshots {
+		if path.Ext(info.Name()) == ".tmp" {
+			log.Error("temp snapshot file name %s, try remove", info.Name())
+			os.Remove(path.Join(cfg.Snapshot.Path, info.Name()))
+			continue
+		}
+
+		if _, err := parseSnapshotName(info.Name()); err != nil {
+			log.Error("invalid snapshot file name %s, err: %s, try remove", info.Name(), err.Error())
+			continue
+		}
+
+		names = append(names, info.Name())
+	}
+
+	//from old to new
+	sort.Strings(names)
+
+	s.names = names
+
+	s.purge(false)
+
+	return nil
+}
+
 func (s *snapshotStore) run() {
-	t := time.NewTicker(1 * time.Minute)
+	t := time.NewTicker(60 * time.Minute)
 	defer t.Stop()
 
 	for {
 		select {
 		case <-t.C:
 			s.Lock()
-			s.purge(false)
+			if err := s.checkSnapshots(); err != nil {
+				log.Error("check snapshots error %s", err.Error())
+			}
 			s.Unlock()
 		case <-s.quit:
 			return
@@ -138,6 +161,8 @@ type snapshot struct {
 	io.ReadCloser
 
 	f *os.File
+
+	temp bool
 }
 
 func (st *snapshot) Read(b []byte) (int, error) {
@@ -145,7 +170,15 @@ func (st *snapshot) Read(b []byte) (int, error) {
 }
 
 func (st *snapshot) Close() error {
+	if st.temp {
+		name := st.f.Name()
+		if err := st.f.Close(); err != nil {
+			return err
+		}
+		return os.Remove(name)
+	} else {
 		return st.f.Close()
+	}
 }
 
 func (st *snapshot) Size() int64 {
@@ -153,37 +186,58 @@ func (st *snapshot) Size() int64 {
 	return s.Size()
 }
 
-func (s *snapshotStore) Create(d snapshotDumper) (*snapshot, time.Time, error) {
+func (s *snapshotStore) Create(d snapshotDumper, temp bool) (*snapshot, time.Time, error) {
 	s.Lock()
 	defer s.Unlock()
 
+	if !temp {
 		s.purge(true)
+	}
 
 	now := time.Now()
 	name := snapshotName(now)
 
-	if len(s.names) > 0 && s.names[len(s.names)-1] >= name {
+	tmpName := name + ".tmp"
-		return nil, time.Time{}, fmt.Errorf("create snapshot file time %s is behind %s ", name, s.names[len(s.names)-1])
+
+	if len(s.names) > 0 && !temp {
+		lastTime, _ := parseSnapshotName(s.names[len(s.names)-1])
+		if !now.After(lastTime) {
+			return nil, time.Time{}, fmt.Errorf("create snapshot file time %s is behind %s ",
+				now.Format(snapshotTimeFormat), lastTime.Format(snapshotTimeFormat))
+		}
 	}
 
-	f, err := os.OpenFile(s.snapshotPath(name), os.O_RDWR|os.O_CREATE, 0644)
+	f, err := os.OpenFile(s.snapshotPath(tmpName), os.O_RDWR|os.O_CREATE, 0644)
 	if err != nil {
 		return nil, time.Time{}, err
 	}
 
 	if err := d.Dump(f); err != nil {
 		f.Close()
-		os.Remove(s.snapshotPath(name))
+		os.Remove(s.snapshotPath(tmpName))
 		return nil, time.Time{}, err
 	}
 
-	f.Sync()
+	if temp {
-
+		if err := f.Sync(); err != nil {
-	s.names = append(s.names, name)
+			f.Close()
+			return nil, time.Time{}, err
+		}
 
 		f.Seek(0, os.SEEK_SET)
+	} else {
+		f.Close()
+		if err := os.Rename(s.snapshotPath(tmpName), s.snapshotPath(name)); err != nil {
+			return nil, time.Time{}, err
+		}
 
-	return &snapshot{f: f}, now, nil
+		if f, err = os.Open(s.snapshotPath(name)); err != nil {
+			return nil, time.Time{}, err
+		}
+		s.names = append(s.names, name)
+	}
+
+	return &snapshot{f: f, temp: temp}, now, nil
 }
 
 func (s *snapshotStore) OpenLatest() (*snapshot, time.Time, error) {
@@ -202,5 +256,5 @@ func (s *snapshotStore) OpenLatest() (*snapshot, time.Time, error) {
 		return nil, time.Time{}, err
 	}
 
-	return &snapshot{f: f}, t, err
+	return &snapshot{f: f, temp: false}, t, err
 }

server/snapshot_test.go

@@ -30,7 +30,7 @@ func TestSnapshot(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	if f, _, err := s.Create(d); err != nil {
+	if f, _, err := s.Create(d, false); err != nil {
 		t.Fatal(err)
 	} else {
 		defer f.Close()
@@ -43,7 +43,7 @@ func TestSnapshot(t *testing.T) {
 		}
 	}
 
-	if f, _, err := s.Create(d); err != nil {
+	if f, _, err := s.Create(d, false); err != nil {
 		t.Fatal(err)
 	} else {
 		defer f.Close()
@@ -55,7 +55,7 @@ func TestSnapshot(t *testing.T) {
 		}
 	}
 
-	if f, _, err := s.Create(d); err != nil {
+	if f, _, err := s.Create(d, false); err != nil {
 		t.Fatal(err)
 	} else {
 		defer f.Close()
@@ -73,5 +73,29 @@ func TestSnapshot(t *testing.T) {
 		t.Fatal("must 2 snapshot")
 	}
 
+	if f, _, err := s.Create(d, true); err != nil {
+		t.Fatal(err)
+	} else {
+		if b, _ := ioutil.ReadAll(f); string(b) != "hello world" {
+			t.Fatal("invalid read snapshot")
+		}
+
+		if len(s.names) != 2 {
+			t.Fatal("must 2 snapshot")
+		}
+
+		fs, _ = ioutil.ReadDir(cfg.Snapshot.Path)
+		if len(fs) != 3 {
+			t.Fatal("must 3 snapshot")
+		}
+
+		f.Close()
+	}
+
+	fs, _ = ioutil.ReadDir(cfg.Snapshot.Path)
+	if len(fs) != 2 {
+		t.Fatal("must 2 snapshot")
+	}
+
 	s.Close()
 }