Expose additional raft properties

Signed-off-by: Joshua Zhang <joshua.x.zhang@gmail.com>

Author: joshuazh-x

node.go

@@ -128,6 +128,10 @@ func IsEmptySnap(sp pb.Snapshot) bool {
 	return sp.Metadata.Index == 0
 }
 
+type CustomCommand interface {
+	Do(rn *RawNode)
+}
+
 // Node represents a node in a raft cluster.
 type Node interface {
 	// Tick increments the internal logical clock for the Node by a single tick. Election
@@ -240,6 +244,8 @@ type Node interface {
 	ReportSnapshot(id uint64, status SnapshotStatus)
 	// Stop performs any necessary termination of the Node.
 	Stop()
+
+	DoCustomCommand(ctx context.Context, cmd CustomCommand) error
 }
 
 type Peer struct {
@@ -305,6 +311,7 @@ type node struct {
 	done       chan struct{}
 	stop       chan struct{}
 	status     chan chan Status
+	cmdc       chan CustomCommand
 
 	rn *RawNode
 }
@@ -324,6 +331,7 @@ func newNode(rn *RawNode) node {
 		done:   make(chan struct{}),
 		stop:   make(chan struct{}),
 		status: make(chan chan Status),
+		cmdc:   make(chan CustomCommand),
 		rn:     rn,
 	}
 }
@@ -446,6 +454,8 @@ func (n *node) run() {
 			advancec = nil
 		case c := <-n.status:
 			c <- getStatus(r)
+		case cmd := <-n.cmdc:
+			cmd.Do(n.rn)
 		case <-n.stop:
 			close(n.done)
 			return
@@ -608,3 +618,14 @@ func (n *node) ForgetLeader(ctx context.Context) error {
 func (n *node) ReadIndex(ctx context.Context, rctx []byte) error {
 	return n.step(ctx, pb.Message{Type: pb.MsgReadIndex, Entries: []pb.Entry{{Data: rctx}}})
 }
+
+func (n *node) DoCustomCommand(ctx context.Context, cmd CustomCommand) error {
+	select {
+	case n.cmdc <- cmd:
+		return nil
+	case <-n.done:
+		return ErrStopped
+	case <-ctx.Done():
+		return ctx.Err()
+	}
+}

rawnode.go

@@ -560,3 +560,11 @@ func (rn *RawNode) ForgetLeader() error {
 func (rn *RawNode) ReadIndex(rctx []byte) {
 	_ = rn.raft.Step(pb.Message{Type: pb.MsgReadIndex, Entries: []pb.Entry{{Data: rctx}}})
 }
+
+func (rn *RawNode) GetVotes() map[uint64]bool {
+	votes := make(map[uint64]bool, len(rn.raft.trk.Votes))
+	for k, v := range rn.raft.trk.Votes {
+		votes[k] = v
+	}
+	return votes
+}

status.go

@@ -39,6 +39,9 @@ type BasicStatus struct {
 	Applied uint64
 
 	LeadTransferee uint64
+
+	LastLogIndex uint64
+	LastLogTerm  uint64
 }
 
 func getProgressCopy(r *raft) map[uint64]tracker.Progress {
@@ -61,6 +64,9 @@ func getBasicStatus(r *raft) BasicStatus {
 	s.HardState = r.hardState()
 	s.SoftState = r.softState()
 	s.Applied = r.raftLog.applied
+	e := r.raftLog.lastEntryID()
+	s.LastLogIndex = e.index
+	s.LastLogTerm = e.term
 	return s
 }