Simplify peer count processing

That is, now that peerNumber == activePeerNumber ==
len(syncConfig.peers), remove the peer count variables.

Also remove CleanupNilPeers(), whose purpose was solely to update
activePeerNUmber.

api/service/syncing/syncing.go

@@ -86,8 +86,6 @@ type StateSync struct {
 	selfip             string
 	selfport           string
 	selfPeerHash       [20]byte // hash of ip and address combination
-	peerNumber         int
-	activePeerNumber   int
 	commonBlocks       map[int]*types.Block
 	lastMileBlocks     []*types.Block // last mile blocks to catch up with the consensus
 	syncConfig         *SyncConfig
@@ -166,11 +164,10 @@ func (ss *StateSync) CreateSyncConfig(peers []p2p.Peer) error {
 	if len(peers) == 0 {
 		return ctxerror.New("[SYNC] no peers to connect to")
 	}
-	ss.peerNumber = len(peers)
 	ss.syncConfig = &SyncConfig{}
 	var wg sync.WaitGroup
-	wg.Add(ss.peerNumber)
 	for _, peer := range peers {
+		wg.Add(1)
 		go func(peer p2p.Peer) {
 			defer wg.Done()
 			client := downloader.ClientSetup(peer.IP, peer.Port)
@@ -186,7 +183,6 @@ func (ss *StateSync) CreateSyncConfig(peers []p2p.Peer) error {
 		}(peer)
 	}
 	wg.Wait()
-	ss.CleanUpNilPeers()
 	utils.GetLogInstance().Info("[SYNC] Finished making connection to peers.")
 
 	return nil
@@ -194,22 +190,10 @@ func (ss *StateSync) CreateSyncConfig(peers []p2p.Peer) error {
 
 // GetActivePeerNumber returns the number of active peers
 func (ss *StateSync) GetActivePeerNumber() int {
-	if ss.syncConfig == nil || len(ss.syncConfig.peers) == 0 {
+	if ss.syncConfig == nil {
 		return 0
 	}
-	ss.CleanUpNilPeers()
+	return len(ss.syncConfig.peers)
-	return ss.activePeerNumber
-}
-
-// CleanUpNilPeers cleans up peer with nil client and recalculate activePeerNumber.
-func (ss *StateSync) CleanUpNilPeers() {
-	ss.activePeerNumber = 0
-	for _, configPeer := range ss.syncConfig.peers {
-		if configPeer.client != nil {
-			ss.activePeerNumber++
-		}
-	}
-	utils.GetLogInstance().Info("[SYNC] clean up inactive peers", "activeNumber", ss.activePeerNumber)
 }
 
 // GetHowManyMaxConsensus returns max number of consensus nodes and the first ID of consensus group.
@@ -267,9 +251,8 @@ func (ss *StateSync) GetBlockHashesConsensusAndCleanUp() bool {
 	})
 	maxFirstID, maxCount := ss.syncConfig.GetHowManyMaxConsensus()
 	utils.GetLogInstance().Info("[SYNC] block consensus hashes", "maxFirstID", maxFirstID, "maxCount", maxCount)
-	if float64(maxCount) >= ConsensusRatio*float64(ss.activePeerNumber) {
+	if float64(maxCount) >= ConsensusRatio*float64(len(ss.syncConfig.peers)) {
 		ss.syncConfig.CleanUpPeers(maxFirstID)
-		ss.CleanUpNilPeers()
 		return true
 	}
 	return false
@@ -326,7 +309,7 @@ func (ss *StateSync) generateStateSyncTaskQueue(bc *core.BlockChain) {
 func (ss *StateSync) downloadBlocks(bc *core.BlockChain) {
 	// Initialize blockchain
 	var wg sync.WaitGroup
-	wg.Add(ss.activePeerNumber)
+	wg.Add(len(ss.syncConfig.peers))
 	count := 0
 	for i := range ss.syncConfig.peers {
 		if ss.syncConfig.peers[i].client == nil {
@@ -546,9 +529,10 @@ func (peerConfig *SyncPeerConfig) registerToBroadcast(peerHash []byte, ip, port
 // RegisterNodeInfo will register node to peers to accept future new block broadcasting
 // return number of successfull registration
 func (ss *StateSync) RegisterNodeInfo() int {
-	ss.CleanUpNilPeers()
 	registrationNumber := RegistrationNumber
-	utils.GetLogInstance().Debug("[SYNC] node registration to peers", "registrationNumber", registrationNumber, "activePeerNumber", ss.activePeerNumber)
+	utils.GetLogInstance().Debug("[SYNC] node registration to peers",
+		"registrationNumber", registrationNumber,
+		"activePeerNumber", len(ss.syncConfig.peers))
 
 	count := 0
 	for id := range ss.syncConfig.peers {
@@ -576,7 +560,6 @@ func (ss *StateSync) RegisterNodeInfo() int {
 
 // getMaxPeerHeight gets the maximum blockchain heights from peers
 func (ss *StateSync) getMaxPeerHeight() uint64 {
-	ss.CleanUpNilPeers()
 	maxHeight := uint64(0)
 	var wg sync.WaitGroup
 	for id := range ss.syncConfig.peers {