tweaks to address code review comments

client.go

@@ -122,14 +122,14 @@ func (client *Client) Partitions(topic string) ([]int32, error) {
 		return nil, ClosedClient
 	}
 
-	partitions := client.cachedPartitions(topic, false)
+	partitions := client.cachedPartitions(topic, allPartitions)
 
 	if len(partitions) == 0 {
 		err := client.RefreshTopicMetadata(topic)
 		if err != nil {
 			return nil, err
 		}
-		partitions = client.cachedPartitions(topic, false)
+		partitions = client.cachedPartitions(topic, allPartitions)
 	}
 
 	if partitions == nil {
@@ -147,7 +147,7 @@ func (client *Client) WritablePartitions(topic string) ([]int32, error) {
 		return nil, ClosedClient
 	}
 
-	partitions := client.cachedPartitions(topic, true)
+	partitions := client.cachedPartitions(topic, writablePartitions)
 
 	// len==0 catches when it's nil (no such topic) and the odd case when every single
 	// partition is undergoing leader election simultaneously. Callers have to be able to handle
@@ -160,7 +160,7 @@ func (client *Client) WritablePartitions(topic string) ([]int32, error) {
 		if err != nil {
 			return nil, err
 		}
-		partitions = client.cachedPartitions(topic, true)
+		partitions = client.cachedPartitions(topic, writablePartitions)
 	}
 
 	if partitions == nil {
@@ -451,7 +451,12 @@ func (client *Client) cachedMetadata(topic string, partitionID int32) *Partition
 	return nil
 }
 
-func (client *Client) cachedPartitions(topic string, onlyWritable bool) []int32 {
+const (
+	allPartitions = iota
+	writablePartitions
+)
+
+func (client *Client) cachedPartitions(topic string, partitionSet int) []int32 {
 	client.lock.RLock()
 	defer client.lock.RUnlock()
 
@@ -462,7 +467,7 @@ func (client *Client) cachedPartitions(topic string, onlyWritable bool) []int32
 
 	ret := make([]int32, 0, len(partitions))
 	for _, partition := range partitions {
-		if onlyWritable && partition.Err == LeaderNotAvailable {
+		if partitionSet == writablePartitions && partition.Err == LeaderNotAvailable {
 			continue
 		}
 		ret = append(ret, partition.ID)
@@ -566,11 +571,11 @@ func NewClientConfig() *ClientConfig {
 // ConfigurationError if the specified values don't make sense.
 func (config *ClientConfig) Validate() error {
 	if config.MetadataRetries < 0 {
-		return ConfigurationError("Invalid MetadataRetries")
+		return ConfigurationError("Invalid MetadataRetries, must be >= 0")
 	}
 
 	if config.WaitForElection <= time.Duration(0) {
-		return ConfigurationError("Invalid WaitForElection")
+		return ConfigurationError("Invalid WaitForElection, must be > 0")
 	}
 
 	if config.DefaultBrokerConf != nil {
@@ -580,7 +585,7 @@ func (config *ClientConfig) Validate() error {
 	}
 
 	if config.BackgroundRefreshFrequency < time.Duration(0) {
-		return ConfigurationError("Invalid BackgroundRefreshFrequency.")
+		return ConfigurationError("Invalid BackgroundRefreshFrequency, must be >= 0")
 	}
 
 	return nil