func (s *Snapshotter) save(snapshot *raftpb.Snapshot) error {
start := time.Now()
fname := fmt.Sprintf("%016x-%016x%s", snapshot.Metadata.Term, snapshot.Metadata.Index, snapSuffix)
b := pbutil.MustMarshal(snapshot)
crc := crc32.Update(0, crcTable, b)
snap := snappb.Snapshot{Crc: crc, Data: b}
d, err := snap.Marshal()
if err != nil {
return err
} else {
marshallingDurations.Observe(float64(time.Since(start).Nanoseconds() / int64(time.Microsecond)))
}
err = ioutil.WriteFile(path.Join(s.dir, fname), d, 0666)
if err == nil {
saveDurations.Observe(float64(time.Since(start).Nanoseconds() / int64(time.Microsecond)))
}
return err
}
// Read reads the snapshot named by snapname and returns the snapshot.
func Read(snapname string) (*raftpb.Snapshot, error) {
b, err := ioutil.ReadFile(snapname)
if err != nil {
plog.Errorf("cannot read file %v: %v", snapname, err)
return nil, err
}
if len(b) == 0 {
plog.Errorf("unexpected empty snapshot")
return nil, ErrEmptySnapshot
}
var serializedSnap snappb.Snapshot
if err = serializedSnap.Unmarshal(b); err != nil {
plog.Errorf("corrupted snapshot file %v: %v", snapname, err)
return nil, err
}
if len(serializedSnap.Data) == 0 || serializedSnap.Crc == 0 {
plog.Errorf("unexpected empty snapshot")
return nil, ErrEmptySnapshot
}
crc := crc32.Update(0, crcTable, serializedSnap.Data)
if crc != serializedSnap.Crc {
plog.Errorf("corrupted snapshot file %v: crc mismatch", snapname)
return nil, ErrCRCMismatch
}
var snap raftpb.Snapshot
if err = snap.Unmarshal(serializedSnap.Data); err != nil {
plog.Errorf("corrupted snapshot file %v: %v", snapname, err)
return nil, err
}
return &snap, nil
}