// HardState contains term, vote and commit.
// Snapshot contains data and snapshot metadata.
func (n *node) saveToStorage(hardState raftpb.HardState,
entries []raftpb.Entry, snapshot raftpb.Snapshot) {
if !raft.IsEmptySnap(snapshot) {
fmt.Printf("saveToStorage snapshot: %v\n", snapshot.String())
le, err := n.store.LastIndex()
if err != nil {
log.Fatalf("While retrieving last index: %v\n", err)
}
te, err := n.store.Term(le)
if err != nil {
log.Fatalf("While retrieving term: %v\n", err)
}
fmt.Printf("%d node Term for le: %v is %v\n", n.id, le, te)
if snapshot.Metadata.Index <= le {
fmt.Printf("%d node ignoring snapshot. Last index: %v\n", n.id, le)
return
}
if err := n.store.ApplySnapshot(snapshot); err != nil {
log.Fatalf("Applying snapshot: %v", err)
}
}
if !raft.IsEmptyHardState(hardState) {
n.store.SetHardState(hardState)
}
n.store.Append(entries)
}
// 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 {
log.Printf("snap: snapshotter cannot read file %v: %v", snapname, err)
return nil, err
}
var serializedSnap snappb.Snapshot
if err = serializedSnap.Unmarshal(b); err != nil {
log.Printf("snap: corrupted snapshot file %v: %v", snapname, err)
return nil, err
}
if len(serializedSnap.Data) == 0 || serializedSnap.Crc == 0 {
log.Printf("snap: unexpected empty snapshot")
return nil, ErrEmptySnapshot
}
crc := crc32.Update(0, crcTable, serializedSnap.Data)
if crc != serializedSnap.Crc {
log.Printf("snap: corrupted snapshot file %v: crc mismatch", snapname)
return nil, ErrCRCMismatch
}
var snap raftpb.Snapshot
if err = snap.Unmarshal(serializedSnap.Data); err != nil {
log.Printf("snap: corrupted snapshot file %v: %v", snapname, err)
return nil, err
}
return &snap, nil
}
func (s *Snapshotter) Save(snapshot *raftpb.Snapshot) error {
fname := fmt.Sprintf("%016x-%016x%s", snapshot.Term, snapshot.Index, snapSuffix)
b, err := snapshot.Marshal()
if err != nil {
panic(err)
}
crc := crc32.Update(0, crcTable, b)
snap := snappb.Snapshot{Crc: crc, Data: b}
d, err := snap.Marshal()
if err != nil {
return err
}
return ioutil.WriteFile(path.Join(s.dir, fname), d, 0666)
}
// Store stores the snapshot, hardstate and entries for a given RAFT group.
func (w *Wal) Store(gid uint32, s raftpb.Snapshot, h raftpb.HardState, es []raftpb.Entry) error {
b := w.wals.NewWriteBatch()
defer b.Destroy()
if !raft.IsEmptySnap(s) {
data, err := s.Marshal()
if err != nil {
return x.Wrapf(err, "wal.Store: While marshal snapshot")
}
b.Put(w.snapshotKey(gid), data)
}
if !raft.IsEmptyHardState(h) {
data, err := h.Marshal()
if err != nil {
return x.Wrapf(err, "wal.Store: While marshal hardstate")
}
b.Put(w.hardStateKey(gid), data)
}
var t, i uint64
for _, e := range es {
t, i = e.Term, e.Index
data, err := e.Marshal()
if err != nil {
return x.Wrapf(err, "wal.Store: While marshal entry")
}
k := w.entryKey(gid, e.Term, e.Index)
b.Put(k, data)
}
// If we get no entries, then the default value of t and i would be zero. That would
// end up deleting all the previous valid raft entry logs. This check avoids that.
if t > 0 || i > 0 {
// Delete all keys above this index.
start := w.entryKey(gid, t, i+1)
prefix := w.prefix(gid)
itr := w.wals.NewIterator()
defer itr.Close()
for itr.Seek(start); itr.ValidForPrefix(prefix); itr.Next() {
b.Delete(itr.Key().Data())
}
}
err := w.wals.WriteBatch(b)
return x.Wrapf(err, "wal.Store: While WriteBatch")
}
func loadSnap(dir, name string) (*raftpb.Snapshot, error) {
var err error
var b []byte
fpath := path.Join(dir, name)
defer func() {
if err != nil {
renameBroken(fpath)
}
}()
b, err = ioutil.ReadFile(fpath)
if err != nil {
log.Printf("snap: snapshotter cannot read file %v: %v", name, err)
return nil, err
}
var serializedSnap snappb.Snapshot
if err = serializedSnap.Unmarshal(b); err != nil {
log.Printf("snap: corrupted snapshot file %v: %v", name, err)
return nil, err
}
if len(serializedSnap.Data) == 0 || serializedSnap.Crc == 0 {
log.Printf("snap: unexpected empty snapshot")
return nil, ErrEmptySnapshot
}
crc := crc32.Update(0, crcTable, serializedSnap.Data)
if crc != serializedSnap.Crc {
log.Printf("snap: corrupted snapshot file %v: crc mismatch", name)
return nil, ErrCRCMismatch
}
var snap raftpb.Snapshot
if err = snap.Unmarshal(serializedSnap.Data); err != nil {
log.Printf("snap: corrupted snapshot file %v: %v", name, err)
return nil, err
}
return &snap, nil
}