func (r *Replication) Log(data []byte) (*Log, error) {
if r.cfg.Replication.Compression {
//todo optimize
var err error
if data, err = snappy.Encode(nil, data); err != nil {
return nil, err
}
}
r.m.Lock()
lastID, err := r.s.LastID()
if err != nil {
r.m.Unlock()
return nil, err
}
commitId := r.commitID
if lastID < commitId {
lastID = commitId
} else if lastID > commitId {
r.m.Unlock()
return nil, ErrCommitIDBehind
}
l := new(Log)
l.ID = lastID + 1
l.CreateTime = uint32(time.Now().Unix())
if r.cfg.Replication.Compression {
l.Compression = 1
} else {
l.Compression = 0
}
l.Data = data
if err = r.s.StoreLog(l); err != nil {
r.m.Unlock()
return nil, err
}
r.m.Unlock()
r.ncm.Lock()
close(r.nc)
r.nc = make(chan struct{})
r.ncm.Unlock()
return l, nil
}
func (l *Ledis) Dump(w io.Writer) error {
var err error
var commitID uint64
var snap *store.Snapshot
l.wLock.Lock()
if l.r != nil {
if commitID, err = l.r.LastCommitID(); err != nil {
l.wLock.Unlock()
return err
}
}
if snap, err = l.ldb.NewSnapshot(); err != nil {
l.wLock.Unlock()
return err
}
l.wLock.Unlock()
wb := bufio.NewWriterSize(w, 4096)
h := &DumpHead{commitID}
if err = h.Write(wb); err != nil {
return err
}
it := snap.NewIterator()
it.SeekToFirst()
compressBuf := make([]byte, 4096)
var key []byte
var value []byte
for ; it.Valid(); it.Next() {
key = it.RawKey()
value = it.RawValue()
if key, err = snappy.Encode(compressBuf, key); err != nil {
return err
}
if err = binary.Write(wb, binary.BigEndian, uint16(len(key))); err != nil {
return err
}
if _, err = wb.Write(key); err != nil {
return err
}
if value, err = snappy.Encode(compressBuf, value); err != nil {
return err
}
if err = binary.Write(wb, binary.BigEndian, uint32(len(value))); err != nil {
return err
}
if _, err = wb.Write(value); err != nil {
return err
}
}
if err = wb.Flush(); err != nil {
return err
}
compressBuf = nil
return nil
}