disable message pool by default

Signed-off-by: Vasiliy Tolstov <v.tolstov@unistack.org>

kgo.go

@@ -478,11 +478,15 @@ func (b *Broker) fnSubscribe(ctx context.Context, topic string, handler interfac
 		}
 	}
 
+	var messagePool bool
 	var fatalOnError bool
 	if b.opts.Context != nil {
 		if v, ok := b.opts.Context.Value(fatalOnErrorKey{}).(bool); ok && v {
 			fatalOnError = v
 		}
+		if v, ok := b.opts.Context.Value(subscribeMessagePoolKey{}).(bool); ok && v {
+			messagePool = v
+		}
 	}
 
 	if options.Context != nil {
@@ -500,6 +504,7 @@ func (b *Broker) fnSubscribe(ctx context.Context, topic string, handler interfac
 		done:         make(chan struct{}),
 		fatalOnError: fatalOnError,
 		connected:    b.connected,
+		messagePool:  messagePool,
 	}
 
 	kopts := append(b.kopts,

options.go

@@ -109,3 +109,10 @@ type publishPromiseKey struct{}
 func PublishPromise(fn func(*kgo.Record, error)) broker.PublishOption {
 	return broker.SetPublishOption(publishPromiseKey{}, fn)
 }
+
+type subscribeMessagePoolKey struct{}
+
+// SubscribeMessagePool optionaly enabled/disable message pool
+func SubscribeMessagePool(b bool) broker.SubscribeOption {
+	return broker.SetSubscribeOption(subscribeMessagePoolKey{}, b)
+}

subscriber.go

@@ -35,6 +35,7 @@ type consumer struct {
 	opts        broker.SubscribeOptions
 	handler     interface{}
 	connected   *atomic.Uint32
+	messagePool bool
 }
 
 type Subscriber struct {
@@ -42,7 +43,7 @@ type Subscriber struct {
 	c           *kgo.Client
 	htracer     *hookTracer
 	topic       string
-
+	messagePool bool
 	handler     interface{}
 	done        chan struct{}
 	kopts       broker.Options
@@ -224,6 +225,7 @@ func (s *Subscriber) assigned(_ context.Context, c *kgo.Client, assigned map[str
 				done:        make(chan struct{}),
 				recs:        make(chan kgo.FetchTopicPartition, 100),
 				handler:     s.handler,
+				messagePool: s.messagePool,
 				kopts:       s.kopts,
 				opts:        s.opts,
 				connected:   s.connected,
@@ -245,6 +247,8 @@ func (pc *consumer) consume() {
 		defer pc.kopts.Logger.Debug(pc.kopts.Context, fmt.Sprintf("killing, topic %s partition %d", pc.topic, pc.partition))
 	}
 
+	var pm *kgoMessage
+
 	for {
 		select {
 		case <-pc.quit:
@@ -254,22 +258,26 @@ func (pc *consumer) consume() {
 				ctx, sp := pc.htracer.WithProcessSpan(record)
 				ts := time.Now()
 				pc.kopts.Meter.Counter(semconv.SubscribeMessageInflight, "endpoint", record.Topic, "topic", record.Topic).Inc()
-				p := messagePool.Get().(*kgoMessage)
 
-				p.body = record.Value
-				p.topic = record.Topic
-				p.ack = false
-				p.hdr = metadata.New(len(record.Headers))
-				p.ctx = ctx
+				if pc.messagePool {
+					pm = messagePool.Get().(*kgoMessage)
+				} else {
+					pm = &kgoMessage{}
+				}
+				pm.body = record.Value
+				pm.topic = record.Topic
+				pm.ack = false
+				pm.hdr = metadata.New(len(record.Headers))
+				pm.ctx = ctx
 				for _, hdr := range record.Headers {
-					p.hdr.Set(hdr.Key, string(hdr.Value))
+					pm.hdr.Set(hdr.Key, string(hdr.Value))
 				}
 
 				switch h := pc.handler.(type) {
 				case func(broker.Message) error:
-					err = h(p)
+					err = h(pm)
 				case func([]broker.Message) error:
-					err = h([]broker.Message{p})
+					err = h([]broker.Message{pm})
 				}
 
 				pc.kopts.Meter.Counter(semconv.SubscribeMessageInflight, "endpoint", record.Topic, "topic", record.Topic).Dec()
@@ -277,16 +285,17 @@ func (pc *consumer) consume() {
 					sp.SetStatus(tracer.SpanStatusError, err.Error())
 					pc.kopts.Meter.Counter(semconv.SubscribeMessageTotal, "endpoint", record.Topic, "topic", record.Topic, "status", "failure").Inc()
 				} else if pc.opts.AutoAck {
-					p.ack = true
+					pm.ack = true
 				}
 
 				te := time.Since(ts)
 				pc.kopts.Meter.Summary(semconv.SubscribeMessageLatencyMicroseconds, "endpoint", record.Topic, "topic", record.Topic).Update(te.Seconds())
 				pc.kopts.Meter.Histogram(semconv.SubscribeMessageDurationSeconds, "endpoint", record.Topic, "topic", record.Topic).Update(te.Seconds())
 
-				ack := p.ack
+				ack := pm.ack
+				if pc.messagePool {
 					messagePool.Put(p)
-
+				}
 				if ack {
 					pc.c.MarkCommitRecords(record)
 				} else {