[staking] ActiveCandidate Exclude Candidate with Expired Endorsement (#…

…4062)

action/protocol/poll/nativestakingV2.go

@@ -7,11 +7,12 @@ import (
 
 	"github.com/iotexproject/go-pkgs/hash"
 	"github.com/iotexproject/iotex-address/address"
+	"github.com/iotexproject/iotex-election/util"
+
 	"github.com/iotexproject/iotex-core/action"
 	"github.com/iotexproject/iotex-core/action/protocol"
 	"github.com/iotexproject/iotex-core/action/protocol/staking"
 	"github.com/iotexproject/iotex-core/state"
-	"github.com/iotexproject/iotex-election/util"
 )
 
 type nativeStakingV2 struct {
@@ -83,6 +84,7 @@ func (ns *nativeStakingV2) CalculateCandidatesByHeight(ctx context.Context, sr p
 		return cands, err
 	}
 	bcCtx := protocol.MustGetBlockchainCtx(ctx)
+	// TODO: put candidates which will expired during current or next epoch behind the active candidates
 	return ns.filterAndSortCandidatesByVoteScore(cands, bcCtx.Tip.Timestamp), nil
 }
 

action/protocol/staking/candidate_statemanager.go

@@ -58,6 +58,13 @@ type (
 		DebitBucketPool(*big.Int, bool) error
 		Commit(context.Context) error
 		SM() protocol.StateManager
+		SR() protocol.StateReader
+	}
+
+	// CandidiateStateCommon is the common interface for candidate state manager and reader
+	CandidiateStateCommon interface {
+		ContainsSelfStakingBucket(uint64) bool
+		SR() protocol.StateReader
 	}
 
 	candSM struct {
@@ -106,6 +113,10 @@ func (csm *candSM) SM() protocol.StateManager {
 	return csm.StateManager
 }
 
+func (csm *candSM) SR() protocol.StateReader {
+	return csm.StateManager
+}
+
 // DirtyView is csm's current state, which reflects base view + applying delta saved in csm's dock
 func (csm *candSM) DirtyView() *ViewData {
 	return &ViewData{

action/protocol/staking/candidate_statereader.go

@@ -65,6 +65,7 @@ type (
 		AllCandidates() CandidateList
 		TotalStakedAmount() *big.Int
 		ActiveBucketsCount() uint64
+		ContainsSelfStakingBucket(index uint64) bool
 	}
 
 	candSR struct {
@@ -110,6 +111,10 @@ func (c *candSR) AllCandidates() CandidateList {
 	return c.view.candCenter.All()
 }
 
+func (c *candSR) ContainsSelfStakingBucket(index uint64) bool {
+	return c.view.candCenter.ContainsSelfStakingBucket(index)
+}
+
 func (c *candSR) TotalStakedAmount() *big.Int {
 	return c.view.bucketPool.Total()
 }

action/protocol/staking/handlers_test.go

@@ -2810,7 +2810,7 @@ func TestProtocol_FetchBucketAndValidate(t *testing.T) {
 		})
 		isSelfStake := true
 		isSelfStakeErr := error(nil)
-		patches.ApplyFunc(isSelfStakeBucket, func(featureCtx protocol.FeatureCtx, csm CandidateStateManager, bucket *VoteBucket) (bool, error) {
+		patches.ApplyFunc(isSelfStakeBucket, func(featureCtx protocol.FeatureCtx, csm CandidiateStateCommon, bucket *VoteBucket) (bool, error) {
 			return isSelfStake, isSelfStakeErr
 		})
 		_, err = p.fetchBucketAndValidate(protocol.FeatureCtx{}, csm, identityset.Address(1), 1, false, false)
@@ -2831,7 +2831,7 @@ func TestProtocol_FetchBucketAndValidate(t *testing.T) {
 				Owner: identityset.Address(1),
 			}, nil
 		})
-		patches.ApplyFunc(isSelfStakeBucket, func(featureCtx protocol.FeatureCtx, csm CandidateStateManager, bucket *VoteBucket) (bool, error) {
+		patches.ApplyFunc(isSelfStakeBucket, func(featureCtx protocol.FeatureCtx, csm CandidiateStateCommon, bucket *VoteBucket) (bool, error) {
 			return false, nil
 		})
 		defer patches.Reset()

action/protocol/staking/protocol.go

@@ -56,8 +56,9 @@ const (
 
 // Errors
 var (
-	ErrWithdrawnBucket = errors.New("the bucket is already withdrawn")
-	TotalBucketKey     = append([]byte{_const}, []byte("totalBucket")...)
+	ErrWithdrawnBucket     = errors.New("the bucket is already withdrawn")
+	ErrEndorsementNotExist = errors.New("the endorsement does not exist")
+	TotalBucketKey         = append([]byte{_const}, []byte("totalBucket")...)
 )
 
 var (
@@ -472,6 +473,31 @@ func (p *Protocol) Validate(ctx context.Context, act action.Action, sr protocol.
 	return nil
 }
 
+func (p *Protocol) isActiveCandidate(ctx context.Context, csr CandidateStateReader, cand *Candidate) (bool, error) {
+	if cand.SelfStake.Cmp(p.config.RegistrationConsts.MinSelfStake) < 0 {
+		return false, nil
+	}
+	featureCtx := protocol.MustGetFeatureCtx(ctx)
+	if featureCtx.DisableDelegateEndorsement {
+		// before endorsement feature, candidates with enough amount must be active
+		return true, nil
+	}
+	bucket, err := csr.getBucket(cand.SelfStakeBucketIdx)
+	switch {
+	case errors.Cause(err) == state.ErrStateNotExist:
+		// endorse bucket has been withdrawn
+		return false, nil
+	case err != nil:
+		return false, errors.Wrapf(err, "failed to get bucket %d", cand.SelfStakeBucketIdx)
+	default:
+	}
+	selfStake, err := isSelfStakeBucket(featureCtx, csr, bucket)
+	if err != nil {
+		return false, errors.Wrapf(err, "failed to check self-stake bucket %d", cand.SelfStakeBucketIdx)
+	}
+	return selfStake, nil
+}
+
 // ActiveCandidates returns all active candidates in candidate center
 func (p *Protocol) ActiveCandidates(ctx context.Context, sr protocol.StateReader, height uint64) (state.CandidateList, error) {
 	srHeight, err := sr.Height()
@@ -496,7 +522,11 @@ func (p *Protocol) ActiveCandidates(ctx context.Context, sr protocol.StateReader
 			}
 			list[i].Votes.Add(list[i].Votes, contractVotes)
 		}
-		if list[i].SelfStake.Cmp(p.config.RegistrationConsts.MinSelfStake) >= 0 {
+		active, err := p.isActiveCandidate(ctx, c, list[i])
+		if err != nil {
+			return nil, err
+		}
+		if active {
 			cand = append(cand, list[i])
 		}
 	}
@@ -686,9 +716,9 @@ func writeCandCenterStateToStateDB(sm protocol.StateManager, name, op, owners Ca
 }
 
 // isSelfStakeBucket returns true if the bucket is self-stake bucket and not expired
-func isSelfStakeBucket(featureCtx protocol.FeatureCtx, csm CandidateStateManager, bucket *VoteBucket) (bool, error) {
+func isSelfStakeBucket(featureCtx protocol.FeatureCtx, csc CandidiateStateCommon, bucket *VoteBucket) (bool, error) {
 	// bucket index should be settled in one of candidates
-	selfStake := csm.ContainsSelfStakingBucket(bucket.Index)
+	selfStake := csc.ContainsSelfStakingBucket(bucket.Index)
 	if featureCtx.DisableDelegateEndorsement || !selfStake {
 		return selfStake, nil
 	}
@@ -698,7 +728,7 @@ func isSelfStakeBucket(featureCtx protocol.FeatureCtx, csm CandidateStateManager
 		return !bucket.isUnstaked(), nil
 	}
 	// otherwise bucket should be an endorse bucket which is not expired
-	esm := NewEndorsementStateManager(csm.SM())
+	esm := NewEndorsementStateReader(csc.SR())
 	height, err := esm.Height()
 	if err != nil {
 		return false, err