refactor: use maps.Copy to simplify the code (#4741)

Signed-off-by: withtimezone <with_timezone@outlook.com>
Co-authored-by: CoderZhi <thecoderzhi@gmail.com>

Author: withtimezone

action/protocol/execution/evm/access_list.go

@@ -6,6 +6,8 @@
 package evm
 
 import (
+	"maps"
+
 	"github.com/ethereum/go-ethereum/common"
 )
 
@@ -46,9 +48,7 @@ func newAccessList() *accessList {
 // Copy creates an independent copy of an accessList.
 func (al *accessList) Copy() *accessList {
 	cp := newAccessList()
-	for k, v := range al.addresses {
-		cp.addresses[k] = v
-	}
+	maps.Copy(cp.addresses, al.addresses)
 	cp.slots = make([]map[common.Hash]struct{}, len(al.slots))
 	for i, slotMap := range al.slots {
 		newSlotmap := make(map[common.Hash]struct{}, len(slotMap))

action/protocol/execution/evm/evmstatedbadapter.go

@@ -10,6 +10,7 @@ import (
 	"context"
 	"encoding/hex"
 	"fmt"
+	"maps"
 	"math/big"
 	"sort"
 
@@ -800,9 +801,7 @@ func (stateDB *StateDBAdapter) Snapshot() int {
 	}
 	// save a copy of current SelfDestruct accounts
 	sa := make(deleteAccount)
-	for k, v := range stateDB.selfDestructed {
-		sa[k] = v
-	}
+	maps.Copy(sa, stateDB.selfDestructed)
 	stateDB.selfDestructedSnapshot[sn] = sa
 	if !stateDB.fixSnapshotOrder {
 		for _, addr := range stateDB.cachedContractAddrs() {
@@ -812,9 +811,7 @@ func (stateDB *StateDBAdapter) Snapshot() int {
 	stateDB.contractSnapshot[sn] = c
 	// save a copy of preimages
 	p := make(preimageMap)
-	for k, v := range stateDB.preimages {
-		p[k] = v
-	}
+	maps.Copy(p, stateDB.preimages)
 	stateDB.preimageSnapshot[sn] = p
 	// save a copy of access list
 	stateDB.accessListSnapshot[sn] = stateDB.accessList.Copy()
@@ -823,9 +820,7 @@ func (stateDB *StateDBAdapter) Snapshot() int {
 		stateDB.transientStorageSnapshot[sn] = stateDB.transientStorage.Copy()
 		// save a copy of created account map
 		ca := make(createdAccount)
-		for k, v := range stateDB.createdAccount {
-			ca[k] = v
-		}
+		maps.Copy(ca, stateDB.createdAccount)
 		stateDB.createdAccountSnapshot[sn] = ca
 	}
 	return sn

blockindex/contractstaking/cache.go

@@ -8,6 +8,7 @@ package contractstaking
 import (
 	"context"
 	"log"
+	"maps"
 	"math/big"
 	"sync"
 
@@ -289,9 +290,7 @@ func (s *contractStakingCache) Clone() stakingCache {
 	c.candidateBucketMap = make(map[string]map[uint64]bool, len(s.candidateBucketMap))
 	for k, v := range s.candidateBucketMap {
 		c.candidateBucketMap[k] = make(map[uint64]bool, len(v))
-		for k1, v1 := range v {
-			c.candidateBucketMap[k][k1] = v1
-		}
+		maps.Copy(c.candidateBucketMap[k], v)
 	}
 	c.bucketTypeMap = make(map[uint64]*BucketType, len(s.bucketTypeMap))
 	for k, v := range s.bucketTypeMap {
@@ -300,9 +299,7 @@ func (s *contractStakingCache) Clone() stakingCache {
 	c.propertyBucketTypeMap = make(map[int64]map[uint64]uint64, len(s.propertyBucketTypeMap))
 	for k, v := range s.propertyBucketTypeMap {
 		c.propertyBucketTypeMap[k] = make(map[uint64]uint64, len(v))
-		for k1, v1 := range v {
-			c.propertyBucketTypeMap[k][k1] = v1
-		}
+		maps.Copy(c.propertyBucketTypeMap[k], v)
 	}
 	c.deltaBucketTypes = make(map[uint64]*BucketType, len(s.deltaBucketTypes))
 	for k, v := range s.deltaBucketTypes {

blockindex/contractstaking/wrappedcache.go

@@ -7,6 +7,7 @@ package contractstaking
 
 import (
 	"context"
+	"maps"
 	"math/big"
 	"sort"
 	"sync"
@@ -271,9 +272,7 @@ func (wc *wrappedCache) Clone() stakingCache {
 	updatedCandidates := make(map[string]map[uint64]bool, len(wc.updatedCandidates))
 	for delegate, buckets := range wc.updatedCandidates {
 		updatedBuckets := make(map[uint64]bool, len(buckets))
-		for id, updated := range buckets {
-			updatedBuckets[id] = updated
-		}
+		maps.Copy(updatedBuckets, buckets)
 		updatedCandidates[delegate] = updatedBuckets
 	}
 	return &wrappedCache{

dispatcher/dispatcher.go

@@ -7,6 +7,7 @@ package dispatcher
 
 import (
 	"context"
+	"maps"
 	"sync"
 	"time"
 
@@ -186,9 +187,7 @@ func (d *IotxDispatcher) EventAudit() map[iotexrpc.MessageType]int {
 	d.eventAuditLock.RLock()
 	defer d.eventAuditLock.RUnlock()
 	snapshot := make(map[iotexrpc.MessageType]int)
-	for k, v := range d.eventAudit {
-		snapshot[k] = v
-	}
+	maps.Copy(snapshot, d.eventAudit)
 	return snapshot
 }