add native staking cache (#1877)

Author: CoderZhi

action/protocol/poll/nativestaking.go

@@ -39,6 +39,8 @@ type (
 		getTipBlockTime GetTipBlockTime
 		contract        string
 		abi             abi.ABI
+		bufferHeight    uint64
+		bufferResult    *VoteTally
 	}
 
 	pygg struct {
@@ -75,19 +77,24 @@ func NewNativeStaking(cm protocol.ChainManager, getTipBlockTime GetTipBlockTime)
 		cm:              cm,
 		getTipBlockTime: getTipBlockTime,
 		abi:             abi,
+		bufferHeight:    0,
+		bufferResult:    nil,
 	}, nil
 }
 
 // Votes returns the votes on height
-func (ns *NativeStaking) Votes(correctGas bool) (*VoteTally, time.Time, error) {
+func (ns *NativeStaking) Votes(height uint64, correctGas bool) (*VoteTally, time.Time, error) {
 	if ns.contract == "" {
 		return nil, time.Time{}, ErrNoData
 	}
-
 	now, err := ns.getTipBlockTime()
 	if err != nil {
 		return nil, time.Time{}, errors.Wrap(err, "failed to get current block time")
 	}
+	if ns.bufferHeight == height && ns.bufferResult != nil {
+		log.L().Info("Using cache native staking data", zap.Uint64("height", height))
+		return ns.bufferResult, now, nil
+	}
 	// read voter list from staking contract
 	votes := VoteTally{
 		Candidates: make(map[[12]byte]*state.Candidate),
@@ -114,6 +121,8 @@ func (ns *NativeStaking) Votes(correctGas bool) (*VoteTally, time.Time, error) {
 		}
 		prevIndex = index
 	}
+	ns.bufferHeight = height
+	ns.bufferResult = &votes
 	return &votes, now, nil
 }
 

action/protocol/poll/staking_committee.go

@@ -133,7 +133,7 @@ func (sc *stakingCommittee) DelegatesByHeight(height uint64) (state.CandidateLis
 	}
 
 	timer = sc.timerFactory.NewTimer("Native")
-	nativeVotes, ts, err := sc.nativeStaking.Votes(sc.hu.IsPost(config.Daytona, height))
+	nativeVotes, ts, err := sc.nativeStaking.Votes(height, sc.hu.IsPost(config.Daytona, height))
 	timer.End()
 	if err == ErrNoData {
 		// no native staking data

e2etest/staking_test.go

@@ -112,9 +112,9 @@ func TestStakingContract(t *testing.T) {
 		})
 		require.NoError(err)
 		ns.SetContract(r.ContractAddress)
-		tally, now, err := ns.Votes(false)
+		tally, now, err := ns.Votes(bc.TipHeight()+1, false)
 		require.Equal(poll.ErrNoData, err)
-		tally, now, err = ns.Votes(true)
+		tally, now, err = ns.Votes(bc.TipHeight()+1, true)
 		require.NoError(err)
 		require.Equal(fixedTime, now)
 		require.Equal(numVoter*int(numBucket), len(tally.Candidates))