[staking] Handling CandidateEndorsement Action (#4020)

action/candidate_endorsement.go

@@ -29,8 +29,8 @@ func (act *CandidateEndorsement) BucketIndex() uint64 {
 	return act.bucketIndex
 }
 
-// Endorse returns true if the action is to endorse a candidate
-func (act *CandidateEndorsement) Endorse() bool {
+// IsEndorse returns true if the action is to endorse a candidate
+func (act *CandidateEndorsement) IsEndorse() bool {
 	return act.endorse
 }
 

action/protocol/staking/handler_candidate_endorsement.go

@@ -0,0 +1,86 @@
+package staking
+
+import (
+	"context"
+
+	"github.com/iotexproject/iotex-address/address"
+	"github.com/pkg/errors"
+
+	"github.com/iotexproject/iotex-core/action"
+	"github.com/iotexproject/iotex-core/action/protocol"
+	"github.com/iotexproject/iotex-core/pkg/util/byteutil"
+)
+
+const (
+	handleCandidateEndorsement = "candidateEndorsement"
+)
+
+func (p *Protocol) handleCandidateEndorsement(ctx context.Context, act *action.CandidateEndorsement, csm CandidateStateManager) (*receiptLog, []*action.TransactionLog, error) {
+	actCtx := protocol.MustGetActionCtx(ctx)
+	featureCtx := protocol.MustGetFeatureCtx(ctx)
+	log := newReceiptLog(p.addr.String(), handleCandidateEndorsement, featureCtx.NewStakingReceiptFormat)
+
+	bucket, rErr := p.fetchBucket(csm, act.BucketIndex())
+	if rErr != nil {
+		return log, nil, rErr
+	}
+	cand := csm.GetByOwner(bucket.Candidate)
+	if cand == nil {
+		return log, nil, errCandNotExist
+	}
+	log.AddTopics(byteutil.Uint64ToBytesBigEndian(bucket.Index), bucket.Candidate.Bytes(), []byte{byteutil.BoolToByte(act.IsEndorse())})
+
+	esm := NewEndorsementStateManager(csm.SM())
+	expireHeight := uint64(0)
+	if act.IsEndorse() {
+		// handle endorsement
+		if err := p.validateEndorsement(ctx, csm, esm, actCtx.Caller, bucket, cand); err != nil {
+			return log, nil, err
+		}
+		expireHeight = uint64(endorsementNotExpireHeight)
+	} else {
+		// handle withdrawal
+		if err := p.validateEndorsementWithdrawal(ctx, esm, actCtx.Caller, bucket); err != nil {
+			return log, nil, err
+		}
+		// expire immediately if the bucket is not self-staked
+		// otherwise, expire after withdraw waiting period
+		expireHeight = protocol.MustGetBlockCtx(ctx).BlockHeight
+		if csm.ContainsSelfStakingBucket(bucket.Index) {
+			expireHeight += p.config.EndorsementWithdrawWaitingBlocks
+		}
+	}
+	// update endorsement state
+	if err := esm.Put(bucket.Index, &Endorsement{
+		ExpireHeight: expireHeight,
+	}); err != nil {
+		return log, nil, errors.Wrapf(err, "failed to put endorsement with bucket index %d", bucket.Index)
+	}
+	return log, nil, nil
+}
+
+func (p *Protocol) validateEndorsement(ctx context.Context, csm CandidateStateManager, esm *EndorsementStateManager, caller address.Address, bucket *VoteBucket, cand *Candidate) ReceiptError {
+	if err := validateBucketOwner(bucket, caller); err != nil {
+		return err
+	}
+	if err := validateBucketMinAmount(bucket, p.config.RegistrationConsts.MinSelfStake); err != nil {
+		return err
+	}
+	if err := validateBucketStake(bucket, true); err != nil {
+		return err
+	}
+	if err := validateBucketCandidate(bucket, cand.Owner); err != nil {
+		return err
+	}
+	if err := validateBucketSelfStake(csm, bucket, false); err != nil {
+		return err
+	}
+	return validateBucketEndorsement(esm, bucket, false, protocol.MustGetBlockCtx(ctx).BlockHeight)
+}
+
+func (p *Protocol) validateEndorsementWithdrawal(ctx context.Context, esm *EndorsementStateManager, caller address.Address, bucket *VoteBucket) ReceiptError {
+	if err := validateBucketOwner(bucket, caller); err != nil {
+		return err
+	}
+	return validateBucketEndorsement(esm, bucket, true, protocol.MustGetBlockCtx(ctx).BlockHeight)
+}