Fix default options and avoid copying options struct

msgbus.go

@@ -224,7 +224,7 @@ type MessageBus struct {
 
 // NewMessageBus creates a new message bus with the provided options
 func NewMessageBus(opts ...Option) (*MessageBus, error) {
-	options := DefaultOptions
+	options := NewDefaultOptions()
 
 	for _, opt := range opts {
 		if err := opt(options); err != nil {
@@ -601,7 +601,7 @@ func (mb *MessageBus) Subscribe(id, topic string, opts ...SubscribeOption) chan
 		log.Debugf("subscriber wants to start from %d", o.Index)
 		err := q.ForEach(func(item interface{}) error {
 			if msg, ok := item.(Message); ok && msg.ID >= o.Index {
-				log.Debugf("found msg #%d", msg.ID)
+				log.Debugf("found msg %s#%d", msg.Topic.Name, msg.ID)
 				select {
 				case ch <- msg:
 					n++

options.go

@@ -33,15 +33,17 @@ const (
 	DefaultNoSync = false
 )
 
-var DefaultOptions = &Options{
-	LogPath: DefaultLogPath,
+func NewDefaultOptions() *Options {
+	return &Options{
+		LogPath: DefaultLogPath,
 
-	BufferLength:   DefaultBufferLength,
-	MaxQueueSize:   DefaultMaxQueueSize,
-	MaxPayloadSize: DefaultMaxPayloadSize,
+		BufferLength:   DefaultBufferLength,
+		MaxQueueSize:   DefaultMaxQueueSize,
+		MaxPayloadSize: DefaultMaxPayloadSize,
 
-	Metrics: DefaultMetrics,
-	NoSync:  DefaultNoSync,
+		Metrics: DefaultMetrics,
+		NoSync:  DefaultNoSync,
+	}
 }
 
 // Options ...