fix: update map rather than create a new map

admin.go

@@ -249,8 +249,9 @@ func (ca *clusterAdmin) CreateTopic(topic string, detail *TopicDetail, validateO
 		return errors.New("you must specify topic details")
 	}
 
-	topicDetails := make(map[string]*TopicDetail)
-	topicDetails[topic] = detail
+	topicDetails := map[string]*TopicDetail{
+		topic: detail,
+	}
 
 	request := NewCreateTopicsRequest(
 		ca.conf.Version,
@@ -366,7 +367,7 @@ func (ca *clusterAdmin) ListTopics() (map[string]TopicDetail, error) {
 		return nil, err
 	}
 
-	topicsDetailsMap := make(map[string]TopicDetail)
+	topicsDetailsMap := make(map[string]TopicDetail, len(metadataResp.Topics))
 
 	var describeConfigsResources []*ConfigResource
 
@@ -375,7 +376,7 @@ func (ca *clusterAdmin) ListTopics() (map[string]TopicDetail, error) {
 			NumPartitions: int32(len(topic.Partitions)),
 		}
 		if len(topic.Partitions) > 0 {
-			topicDetails.ReplicaAssignment = map[int32][]int32{}
+			topicDetails.ReplicaAssignment = make(map[int32][]int32, len(topic.Partitions))
 			for _, partition := range topic.Partitions {
 				topicDetails.ReplicaAssignment[partition.ID] = partition.Replicas
 			}
@@ -479,8 +480,12 @@ func (ca *clusterAdmin) CreatePartitions(topic string, count int32, assignment [
 		return ErrInvalidTopic
 	}
 
-	topicPartitions := make(map[string]*TopicPartition)
-	topicPartitions[topic] = &TopicPartition{Count: count, Assignment: assignment}
+	topicPartitions := map[string]*TopicPartition{
+		topic: {
+			Count:      count,
+			Assignment: assignment,
+		},
+	}
 
 	request := &CreatePartitionsRequest{
 		TopicPartitions: topicPartitions,
@@ -615,13 +620,14 @@ func (ca *clusterAdmin) DeleteRecords(topic string, partitionOffsets map[int32]i
 		partitionPerBroker[broker] = append(partitionPerBroker[broker], partition)
 	}
 	for broker, partitions := range partitionPerBroker {
-		topics := make(map[string]*DeleteRecordsRequestTopic)
-		recordsToDelete := make(map[int32]int64)
+		recordsToDelete := make(map[int32]int64, len(partitions))
 		for _, p := range partitions {
 			recordsToDelete[p] = partitionOffsets[p]
 		}
-		topics[topic] = &DeleteRecordsRequestTopic{
-			PartitionOffsets: recordsToDelete,
+		topics := map[string]*DeleteRecordsRequestTopic{
+			topic: {
+				PartitionOffsets: recordsToDelete,
+			},
 		}
 		request := &DeleteRecordsRequest{
 			Topics:  topics,
@@ -1032,10 +1038,7 @@ func (ca *clusterAdmin) ListConsumerGroups() (allGroups map[string]string, err e
 				return
 			}
 
-			groups := make(map[string]string)
-			maps.Copy(groups, response.Groups)
-
-			groupMaps <- groups
+			groupMaps <- maps.Clone(response.Groups)
 		}(b, ca.conf)
 	}
 
@@ -1204,7 +1207,7 @@ func (ca *clusterAdmin) DescribeLogDirs(brokerIds []int32) (allLogDirs map[int32
 	close(logDirsResults)
 	close(errChan)
 
-	allLogDirs = make(map[int32][]DescribeLogDirsResponseDirMetadata)
+	allLogDirs = make(map[int32][]DescribeLogDirsResponseDirMetadata, len(brokerIds))
 	for logDirsResult := range logDirsResults {
 		allLogDirs[logDirsResult.id] = logDirsResult.logdirs
 	}

balance_strategy.go

@@ -313,16 +313,15 @@ func (s *stickyBalanceStrategy) balance(currentAssignment map[string][]topicPart
 
 	// create a deep copy of the current assignment so we can revert to it if we do not get a more balanced assignment later
 	preBalanceAssignment := deepCopyAssignment(currentAssignment)
-	preBalancePartitionConsumers := make(map[topicPartitionAssignment]string, len(currentPartitionConsumer))
-	maps.Copy(preBalancePartitionConsumers, currentPartitionConsumer)
+	preBalancePartitionConsumers := maps.Clone(currentPartitionConsumer)
 
 	reassignmentPerformed := s.performReassignments(sortedPartitions, currentAssignment, prevAssignment, sortedCurrentSubscriptions, consumer2AllPotentialPartitions, partition2AllPotentialConsumers, currentPartitionConsumer)
 
 	// if we are not preserving existing assignments and we have made changes to the current assignment
 	// make sure we are getting a more balanced assignment; otherwise, revert to previous assignment
 	if !initializing && reassignmentPerformed && getBalanceScore(currentAssignment) >= getBalanceScore(preBalanceAssignment) {
 		currentAssignment = deepCopyAssignment(preBalanceAssignment)
-		currentPartitionConsumer = make(map[topicPartitionAssignment]string, len(preBalancePartitionConsumers))
+		clear(currentPartitionConsumer)
 		maps.Copy(currentPartitionConsumer, preBalancePartitionConsumers)
 	}
 

balance_strategy_test.go

@@ -2202,8 +2202,7 @@ func verifyValidityAndBalance(t *testing.T, consumers map[string]ConsumerGroupMe
 
 	for i, memberID := range members {
 		for assignedTopic := range plan[memberID] {
-			found := slices.Contains(consumers[memberID].Topics, assignedTopic)
-			if !found {
+			if !slices.Contains(consumers[memberID].Topics, assignedTopic) {
 				t.Errorf("Consumer %s had assigned topic %q that wasn't in the list of assignable topics %v", memberID, assignedTopic, consumers[memberID].Topics)
 				t.FailNow()
 			}

mockbroker.go

@@ -86,8 +86,7 @@ func (b *MockBroker) SetLatency(latency time.Duration) {
 // and uses the found MockResponse instance to generate an appropriate reply.
 // If the request type is not found in the map then nothing is sent.
 func (b *MockBroker) SetHandlerByMap(handlerMap map[string]MockResponse) {
-	fnMap := make(map[string]MockResponse)
-	maps.Copy(fnMap, handlerMap)
+	fnMap := maps.Clone(handlerMap)
 	b.setHandler(func(req *request) (res encoderWithHeader) {
 		reqTypeName := reflect.TypeOf(req.body).Elem().Name()
 		mockResponse := fnMap[reqTypeName]
@@ -102,8 +101,7 @@ func (b *MockBroker) SetHandlerByMap(handlerMap map[string]MockResponse) {
 // request is received by the broker, it looks up the request type in the map
 // and invoke the found RequestHandlerFunc instance to generate an appropriate reply.
 func (b *MockBroker) SetHandlerFuncByMap(handlerMap map[string]requestHandlerFunc) {
-	fnMap := make(map[string]requestHandlerFunc)
-	maps.Copy(fnMap, handlerMap)
+	fnMap := maps.Clone(handlerMap)
 	b.setHandler(func(req *request) (res encoderWithHeader) {
 		reqTypeName := reflect.TypeOf(req.body).Elem().Name()
 		return fnMap[reqTypeName](req)

tools/kafka-console-producer/kafka-console-producer.go

@@ -103,8 +103,7 @@ func main() {
 
 	if *headers != "" {
 		var hdrs []sarama.RecordHeader
-		arrHdrs := strings.SplitSeq(*headers, ",")
-		for h := range arrHdrs {
+		for h := range strings.SplitSeq(*headers, ",") {
 			if header := strings.Split(h, ":"); len(header) != 2 {
 				printUsageErrorAndExit("-header should be key:value. Example: -headers=foo:bar,bar:foo")
 			} else {