add consensus service

consensus/consensus_leader.go

@@ -26,9 +26,13 @@ var (
 )
 
 // WaitForNewBlock waits for the next new block to run consensus on
-func (consensus *Consensus) WaitForNewBlock(blockChannel chan *types.Block) {
+func (consensus *Consensus) WaitForNewBlock(blockChannel chan *types.Block, stopChan chan struct{}, stoppedChan chan struct{}) {
 	utils.GetLogInstance().Debug("Waiting for block", "consensus", consensus)
+	go func() {
+		defer close(stoppedChan)
 		for { // keep waiting for new blocks
+			select {
+			default:
 				newBlock := <-blockChannel
 				// TODO: think about potential race condition
 
@@ -52,7 +56,11 @@ func (consensus *Consensus) WaitForNewBlock(blockChannel chan *types.Block) {
 					}
 					time.Sleep(500 * time.Millisecond)
 				}
+			case <-stopChan:
+				return
+			}
 		}
+	}()
 }
 
 // ProcessMessageLeader dispatches consensus message for the leader.

node/service/consensus.go

@@ -0,0 +1,35 @@
+package service
+
+import (
+	"github.com/harmony-one/harmony/consensus"
+	"github.com/harmony-one/harmony/core/types"
+	"github.com/harmony-one/harmony/internal/utils"
+)
+
+// ConsensusService is the consensus service.
+type ConsensusService struct {
+	blockChannel chan *types.Block // The channel to receive new blocks from Node
+	consensus    *consensus.Consensus
+	stopChan     chan struct{}
+	stoppedChan  chan struct{}
+}
+
+// NewConsensusService returns consensus service.
+func NewConsensusService(blockChannel chan *types.Block, consensus *consensus.Consensus) *ConsensusService {
+	return &ConsensusService{blockChannel: blockChannel, consensus: consensus}
+}
+
+// StartService starts service.
+func (cs *ConsensusService) StartService() {
+	cs.stopChan = make(chan struct{})
+	cs.stoppedChan = make(chan struct{})
+	cs.consensus.WaitForNewBlock(cs.blockChannel, cs.stopChan, cs.stoppedChan)
+}
+
+// StopService stops service.
+func (cs *ConsensusService) StopService() {
+	utils.GetLogInstance().Info("Stopping consensus service.")
+	cs.stopChan <- struct{}{}
+	<-cs.stoppedChan
+	utils.GetLogInstance().Info("Consensus service stopped.")
+}