perf(types): Speedup valset.GetByAddress by noticing we do not need t…

…o copy the validator object (cometbft#3129)

Speedup valset.GetByAddress by noticing we do not need to copy the
validator object in ~every single usage, as it operates on read-only
instances.

This acts as a very small speedup to ValidateBlock, and calculating
statistics for enter prevote. In the future we can change data
structures for bigger impact.

If we think this needs more tests to feel comfortable, I think we should
close this PR. Was a driveby change, and there are more impactful things
we can do

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---

- [ ] Tests written/updated
- [ ] Changelog entry added in `.changelog` (we use
[unclog](https://github.com/informalsystems/unclog) to manage our
changelog)
- [x] Updated relevant documentation (`docs/` or `spec/`) and code
comments
- [x] Title follows the [Conventional
Commits](https://www.conventionalcommits.org/en/v1.0.0/) spec

---------

Co-authored-by: Andy Nogueira <[email protected]>
(cherry picked from commit 2e0a6db)

.changelog/unreleased/improvements/3119-speedup-valset-GetByAddress-usages.md

@@ -0,0 +1,2 @@
+- [`types`] Make a new method `GetByAddressMut` for `ValSet`, which does not copy the returned validator.
+  ([\#3119](https://github.com/cometbft/cometbft/issues/3119)

consensus/state.go

@@ -1834,7 +1834,7 @@ func (cs *State) recordMetrics(height int64, block *types.Block) {
 	)
 	for _, ev := range block.Evidence.Evidence {
 		if dve, ok := ev.(*types.DuplicateVoteEvidence); ok {
-			if _, val := cs.Validators.GetByAddress(dve.VoteA.ValidatorAddress); val != nil {
+			if _, val := cs.Validators.GetByAddressMut(dve.VoteA.ValidatorAddress); val != nil {
 				byzantineValidatorsCount++
 				byzantineValidatorsPower += val.VotingPower
 			}
@@ -2381,7 +2381,7 @@ func (cs *State) calculatePrevoteMessageDelayMetrics() {
 
 	var votingPowerSeen int64
 	for _, v := range pl {
-		_, val := cs.Validators.GetByAddress(v.ValidatorAddress)
+		_, val := cs.Validators.GetByAddressMut(v.ValidatorAddress)
 		votingPowerSeen += val.VotingPower
 		if votingPowerSeen >= cs.Validators.TotalVotingPower()*2/3+1 {
 			cs.metrics.QuorumPrevoteDelay.With("proposer_address", cs.Validators.GetProposer().Address.String()).Set(v.Timestamp.Sub(cs.Proposal.Timestamp).Seconds())

consensus/types/round_state.go

@@ -121,7 +121,7 @@ func (rs *RoundState) RoundStateSimple() RoundStateSimple {
 	}
 
 	addr := rs.Validators.GetProposer().Address
-	idx, _ := rs.Validators.GetByAddress(addr)
+	idx, _ := rs.Validators.GetByAddressMut(addr)
 
 	return RoundStateSimple{
 		HeightRoundStep:   fmt.Sprintf("%d/%d/%d", rs.Height, rs.Round, rs.Step),
@@ -140,7 +140,7 @@ func (rs *RoundState) RoundStateSimple() RoundStateSimple {
 // NewRoundEvent returns the RoundState with proposer information as an event.
 func (rs *RoundState) NewRoundEvent() types.EventDataNewRound {
 	addr := rs.Validators.GetProposer().Address
-	idx, _ := rs.Validators.GetByAddress(addr)
+	idx, _ := rs.Validators.GetByAddressMut(addr)
 
 	return types.EventDataNewRound{
 		Height: rs.Height,

internal/test/commit.go

@@ -57,7 +57,7 @@ func MakeCommit(blockID types.BlockID, height int64, round int32, valSet *types.
 		}
 		addr := pk.Address()
 
-		idx, _ := valSet.GetByAddress(addr)
+		idx, _ := valSet.GetByAddressMut(addr)
 		if idx < 0 {
 			return nil, fmt.Errorf("validator with address %s not in validator set", addr)
 		}

types/validation.go

@@ -247,7 +247,7 @@ func verifyCommitBatch(
 		if lookUpByIndex {
 			val = vals.Validators[idx]
 		} else {
-			valIdx, val = vals.GetByAddress(commitSig.ValidatorAddress)
+			valIdx, val = vals.GetByAddressMut(commitSig.ValidatorAddress)
 
 			// if the signature doesn't belong to anyone in the validator set
 			// then we just skip over it

types/validator_set.go

@@ -268,9 +268,21 @@ func (vals *ValidatorSet) HasAddress(address []byte) bool {
 // GetByAddress returns an index of the validator with address and validator
 // itself (copy) if found. Otherwise, -1 and nil are returned.
 func (vals *ValidatorSet) GetByAddress(address []byte) (index int32, val *Validator) {
+	i, val := vals.GetByAddressMut(address)
+	if i == -1 {
+		return -1, nil
+	}
+	return i, val.Copy()
+}
+
+// GetByAddressMut returns an index of the validator with address and the
+// direct validator object if found. Mutations on this return value affect the validator set.
+// This method should be used by callers who will not mutate Val.
+// Otherwise, -1 and nil are returned.
+func (vals *ValidatorSet) GetByAddressMut(address []byte) (index int32, val *Validator) {
 	for idx, val := range vals.Validators {
 		if bytes.Equal(val.Address, address) {
-			return int32(idx), val.Copy()
+			return int32(idx), val
 		}
 	}
 	return -1, nil
@@ -431,7 +443,7 @@ func verifyUpdates(
 ) (tvpAfterUpdatesBeforeRemovals int64, err error) {
 
 	delta := func(update *Validator, vals *ValidatorSet) int64 {
-		_, val := vals.GetByAddress(update.Address)
+		_, val := vals.GetByAddressMut(update.Address)
 		if val != nil {
 			return update.VotingPower - val.VotingPower
 		}
@@ -478,7 +490,7 @@ func numNewValidators(updates []*Validator, vals *ValidatorSet) int {
 func computeNewPriorities(updates []*Validator, vals *ValidatorSet, updatedTotalVotingPower int64) {
 	for _, valUpdate := range updates {
 		address := valUpdate.Address
-		_, val := vals.GetByAddress(address)
+		_, val := vals.GetByAddressMut(address)
 		if val == nil {
 			// add val
 			// Set ProposerPriority to -C*totalVotingPower (with C ~= 1.125) to make sure validators can't
@@ -543,7 +555,7 @@ func verifyRemovals(deletes []*Validator, vals *ValidatorSet) (votingPower int64
 	removedVotingPower := int64(0)
 	for _, valUpdate := range deletes {
 		address := valUpdate.Address
-		_, val := vals.GetByAddress(address)
+		_, val := vals.GetByAddressMut(address)
 		if val == nil {
 			return removedVotingPower, fmt.Errorf("failed to find validator %X to remove", address)
 		}

types/vote_set.go

@@ -404,7 +404,7 @@ func (voteSet *VoteSet) GetByAddress(address []byte) *Vote {
 	}
 	voteSet.mtx.Lock()
 	defer voteSet.mtx.Unlock()
-	valIndex, val := voteSet.valSet.GetByAddress(address)
+	valIndex, val := voteSet.valSet.GetByAddressMut(address)
 	if val == nil {
 		panic("GetByAddress(address) returned nil")
 	}