quorum: minor code simplifications

Epic: none
Release note: none

pkg/raft/quorum/config.go

@@ -12,6 +12,7 @@ package quorum
 
 import (
 	"fmt"
+	"maps"
 	"strings"
 
 	pb "github.com/cockroachdb/cockroach/pkg/raft/raftpb"
@@ -101,20 +102,10 @@ func (c Config) String() string {
 
 // Clone returns a copy of the Config that shares no memory with the original.
 func (c *Config) Clone() Config {
-	clone := func(m map[pb.PeerID]struct{}) map[pb.PeerID]struct{} {
-		if m == nil {
-			return nil
-		}
-		mm := make(map[pb.PeerID]struct{}, len(m))
-		for k := range m {
-			mm[k] = struct{}{}
-		}
-		return mm
-	}
 	return Config{
-		Voters:       JointConfig{clone(c.Voters[0]), clone(c.Voters[1])},
-		Learners:     clone(c.Learners),
-		LearnersNext: clone(c.LearnersNext),
+		Voters:       JointConfig{maps.Clone(c.Voters[0]), maps.Clone(c.Voters[1])},
+		Learners:     maps.Clone(c.Learners),
+		LearnersNext: maps.Clone(c.LearnersNext),
 	}
 }
 

pkg/raft/quorum/joint.go

@@ -36,7 +36,7 @@ func (c JointConfig) String() string {
 // IDs returns a newly initialized map representing the set of voters present
 // in the joint configuration.
 func (c JointConfig) IDs() map[pb.PeerID]struct{} {
-	m := map[pb.PeerID]struct{}{}
+	m := make(map[pb.PeerID]struct{}, len(c[0])+len(c[1]))
 	for _, cc := range c {
 		for id := range cc {
 			m[id] = struct{}{}
@@ -55,12 +55,7 @@ func (c JointConfig) Describe(l AckedIndexer) string {
 // quorum. An index is jointly committed if it is committed in both constituent
 // majorities.
 func (c JointConfig) CommittedIndex(l AckedIndexer) Index {
-	idx0 := c[0].CommittedIndex(l)
-	idx1 := c[1].CommittedIndex(l)
-	if idx0 < idx1 {
-		return idx0
-	}
-	return idx1
+	return min(c[0].CommittedIndex(l), c[1].CommittedIndex(l))
 }
 
 // VoteResult takes a mapping of voters to yes/no (true/false) votes and returns