core: touch nodeSetCache (#466)

3 files changed, 36 insertions, 0 deletions

diff --git a/core/consensus.go b/core/consensus.go
index 0f665f2..b0827fe 100644
--- a/core/consensus.go
+++ b/core/consensus.go
@@ -831,6 +831,16 @@ func (con *Consensus) initialRound(
 		con.initialRound(
 			startHeight+config.RoundLength, nextRound, nextConfig)
 	})
+	// Touch nodeSetCache for next round.
+	con.event.RegisterHeight(startHeight+config.RoundLength*9/10, func(uint64) {
+		go func() {
+			// TODO(jimmy): check DKGResetCount and do not touch if nextRound is reset.
+			if err := con.nodeSetCache.Touch(round + 1); err != nil {
+				con.logger.Warn("Failed to update nodeSetCache",
+					"round", round+1, "error", err)
+			}
+		}()
+	})
 }
 
 // Stop the Consensus core.
diff --git a/core/utils/nodeset-cache.go b/core/utils/nodeset-cache.go
index 6249665..e09120d 100644
--- a/core/utils/nodeset-cache.go
+++ b/core/utils/nodeset-cache.go
@@ -165,6 +165,12 @@ func (cache *NodeSetCache) GetLeaderNode(pos types.Position) (
 	return IDs.leaderNode[pos.Height], nil
 }
 
+// Touch updates the internal cache of round.
+func (cache *NodeSetCache) Touch(round uint64) (err error) {
+	_, err = cache.update(round)
+	return
+}
+
 func (cache *NodeSetCache) cloneMap(
 	nIDs map[types.NodeID]struct{}) map[types.NodeID]struct{} {
 	nIDsCopy := make(map[types.NodeID]struct{}, len(nIDs))
diff --git a/core/utils/nodeset-cache_test.go b/core/utils/nodeset-cache_test.go
index 6d29b6e..fe905cf 100644
--- a/core/utils/nodeset-cache_test.go
+++ b/core/utils/nodeset-cache_test.go
@@ -118,6 +118,26 @@ func (s *NodeSetCacheTestSuite) TestBasicUsage() {
 	}
 }
 
+func (s *NodeSetCacheTestSuite) TestTouch() {
+	var (
+		nsIntf = &nsIntf{
+			s:   s,
+			crs: common.NewRandomHash(),
+		}
+		cache = NewNodeSetCache(nsIntf)
+		req   = s.Require()
+	)
+
+	_, exists := cache.get(1)
+	req.False(exists)
+
+	err := cache.Touch(1)
+	req.NoError(err)
+
+	_, exists = cache.get(1)
+	req.True(exists)
+}
+
 func TestNodeSetCache(t *testing.T) {
 	suite.Run(t, new(NodeSetCacheTestSuite))
 }