Golang Message.Commit方法代码示例

// sendAppend sends RRPC, with entries to the given peer.
func (r *raft) sendAppend(to uint64) {
	pr := r.prs[to]
	if pr.isPaused() {
		return
	}
	m := pb.Message{}
	m.To = to

	term, errt := r.raftLog.term(pr.Next - 1)
	ents, erre := r.raftLog.entries(pr.Next, r.maxMsgSize)

	if errt != nil || erre != nil { // send snapshot if we failed to get term or entries
		m.Type = pb.MsgSnap
		snapshot, err := r.raftLog.snapshot()
		if err != nil {
			if err == ErrSnapshotTemporarilyUnavailable {
				r.logger.Debugf("%x failed to send snapshot to %x because snapshot is temporarily unavailable", r.id, to)
				return
			}
			panic(err) // TODO(bdarnell)
		}
		if IsEmptySnap(snapshot) {
			panic("need non-empty snapshot")
		}
		m.Snapshot = snapshot
		sindex, sterm := snapshot.Metadata.Index, snapshot.Metadata.Term
		r.logger.Debugf("%x [firstindex: %d, commit: %d] sent snapshot[index: %d, term: %d] to %x [%s]",
			r.id, r.raftLog.firstIndex(), r.Commit, sindex, sterm, to, pr)
		pr.becomeSnapshot(sindex)
		r.logger.Debugf("%x paused sending replication messages to %x [%s]", r.id, to, pr)
	} else {
		m.Type = pb.MsgApp
		m.Index = pr.Next - 1
		m.LogTerm = term
		m.Entries = ents
		m.Commit = r.raftLog.committed
		if n := len(m.Entries); n != 0 {
			switch pr.State {
			// optimistically increase the next when in ProgressStateReplicate
			case ProgressStateReplicate:
				last := m.Entries[n-1].Index
				pr.optimisticUpdate(last)
				pr.ins.add(last)
			case ProgressStateProbe:
				pr.pause()
			default:
				r.logger.Panicf("%x is sending append in unhandled state %s", r.id, pr.State)
			}
		}
	}
	r.send(m)
}

func (dec *msgAppV2Decoder) decode() (raftpb.Message, error) {
	var (
		m   raftpb.Message
		typ uint8
	)
	if _, err := io.ReadFull(dec.r, dec.uint8buf); err != nil {
		return m, err
	}
	typ = uint8(dec.uint8buf[0])
	switch typ {
	case msgTypeLinkHeartbeat:
		return linkHeartbeatMessage, nil
	case msgTypeAppEntries:
		m = raftpb.Message{
			Type:    raftpb.MsgApp,
			From:    uint64(dec.remote),
			To:      uint64(dec.local),
			Term:    dec.term,
			LogTerm: dec.term,
			Index:   dec.index,
		}

		// decode entries
		if _, err := io.ReadFull(dec.r, dec.uint64buf); err != nil {
			return m, err
		}
		l := binary.BigEndian.Uint64(dec.uint64buf)
		m.Entries = make([]raftpb.Entry, int(l))
		for i := 0; i < int(l); i++ {
			if _, err := io.ReadFull(dec.r, dec.uint64buf); err != nil {
				return m, err
			}
			size := binary.BigEndian.Uint64(dec.uint64buf)
			var buf []byte
			if size < msgAppV2BufSize {
				buf = dec.buf[:size]
				if _, err := io.ReadFull(dec.r, buf); err != nil {
					return m, err
				}
			} else {
				buf = make([]byte, int(size))
				if _, err := io.ReadFull(dec.r, buf); err != nil {
					return m, err
				}
			}
			dec.index++
			// 1 alloc
			pbutil.MustUnmarshal(&m.Entries[i], buf)
		}
		// decode commit index
		if _, err := io.ReadFull(dec.r, dec.uint64buf); err != nil {
			return m, err
		}
		m.Commit = binary.BigEndian.Uint64(dec.uint64buf)
	case msgTypeApp:
		var size uint64
		if err := binary.Read(dec.r, binary.BigEndian, &size); err != nil {
			return m, err
		}
		buf := make([]byte, int(size))
		if _, err := io.ReadFull(dec.r, buf); err != nil {
			return m, err
		}
		pbutil.MustUnmarshal(&m, buf)

		dec.term = m.Term
		dec.index = m.Index
		if l := len(m.Entries); l > 0 {
			dec.index = m.Entries[l-1].Index
		}
	default:
		return m, fmt.Errorf("failed to parse type %d in msgappv2 stream", typ)
	}
	return m, nil
}