Application testable Delivery - API Change

channel.go

@@ -1391,3 +1391,48 @@ func (me *Channel) Recover(requeue bool) error {
 		&basicRecoverOk{},
 	)
 }
+
+/*
+Ack acknowledges a delivery by its delivery tag when having been consumed with
+Channel.Consume or Channel.Get.
+
+Ack acknowledges all message received prior to the delivery tag when multiple
+is true.
+
+See also Delivery.Ack
+*/
+func (me *Channel) Ack(tag uint64, multiple bool) error {
+	return me.send(me, &basicAck{
+		DeliveryTag: tag,
+		Multiple:    multiple,
+	})
+}
+
+/*
+Nack negatively acknowledges a delivery by its delivery tag.  Prefer this
+method to notify the server that you were not able to process this delivery and
+it must be redelivered or dropped.
+
+See also Delivery.Nack
+*/
+func (me *Channel) Nack(tag uint64, multiple bool, requeue bool) error {
+	return me.send(me, &basicNack{
+		DeliveryTag: tag,
+		Multiple:    multiple,
+		Requeue:     requeue,
+	})
+}
+
+/*
+Reject negatively acknowledges a delivery by its delivery tag.  Prefer Nack
+over Reject when communicating with a RabbitMQ server because you can Nack
+multiple messages, reducing the amount of protocol messages to exchange.
+
+See also Delivery.Reject
+*/
+func (me *Channel) Reject(tag uint64, requeue bool) error {
+	return me.send(me, &basicReject{
+		DeliveryTag: tag,
+		Requeue:     requeue,
+	})
+}

delivery.go

@@ -9,11 +9,21 @@ import (
 	"time"
 )
 
+// Acknowledger notifies the server of successful or failed consumption of
+// delivieries via identifier found in the Delivery.DeliveryTag field.
+//
+// Applications can provide mock implementations in tests of Delivery handlers.
+type Acknowledger interface {
+	Ack(tag uint64, multiple bool) error
+	Nack(tag uint64, multiple bool, requeue bool) error
+	Reject(tag uint64, requeue bool) error
+}
+
 // Delivery captures the fields for a previously delivered message resident in
 // a queue to be delivered by the server to a consumer from Channel.Consume or
 // Channel.Get.
 type Delivery struct {
-	channel *Channel
+	Acknowledger Acknowledger // the channel from which this delivery arrived
 
 	Headers Table // Application or header exchange table
 
@@ -49,7 +59,7 @@ func newDelivery(channel *Channel, msg messageWithContent) *Delivery {
 	props, body := msg.getContent()
 
 	delivery := Delivery{
-		channel: channel,
+		Acknowledger: channel,
 
 		Headers:         props.Headers,
 		ContentType:     props.ContentType,
@@ -89,7 +99,8 @@ func newDelivery(channel *Channel, msg messageWithContent) *Delivery {
 }
 
 /*
-Ack acknowledges that the client or server has finished work on a delivery.
+Ack delegates an acknowledgement through the Acknowledger interface that the
+client or server has finished work on a delivery.
 
 All deliveries in AMQP must be acknowledged.  If you called Channel.Consume
 with autoAck true then the server will be automatically ack each message and
@@ -107,14 +118,11 @@ Either Delivery.Ack, Delivery.Reject or Delivery.Nack must be called for every
 delivery that is not automatically acknowledged.
 */
 func (me Delivery) Ack(multiple bool) error {
-	return me.channel.send(me.channel, &basicAck{
-		DeliveryTag: me.DeliveryTag,
-		Multiple:    multiple,
-	})
+	return me.Acknowledger.Ack(me.DeliveryTag, multiple)
 }
 
 /*
-Reject negatively acknowledge processing of this message.
+Reject delegates a negatively acknowledgement through the Acknowledger interface.
 
 When requeue is true, queue this message to be delivered to a consumer on a
 different channel.  When requeue is false or the server is unable to queue this
@@ -127,28 +135,15 @@ Either Delivery.Ack, Delivery.Reject or Delivery.Nack must be called for every
 delivery that is not automatically acknowledged.
 */
 func (me Delivery) Reject(requeue bool) error {
-	return me.channel.send(me.channel, &basicReject{
-		DeliveryTag: me.DeliveryTag,
-		Requeue:     requeue,
-	})
-}
-
-/*
-Cancel delegates to a Channel.Cancel and uses the consumer identity in this delivery to cancel the consumer.
-
-An error indicates the channel is closed.
-
-*/
-func (me Delivery) Cancel(noWait bool) error {
-	return me.channel.Cancel(me.ConsumerTag, noWait)
+	return me.Acknowledger.Reject(me.DeliveryTag, requeue)
 }
 
 /*
 Nack negatively acknowledge the delivery of message(s) identified by the
-deliveryTag from either the client or server.
+delivery tag from either the client or server.
 
 When multiple is true, nack messages up to and including delivered messages up
-until the deliveryTag delivered on the same channel.
+until the delivery tag delivered on the same channel.
 
 When requeue is true, request the server to deliver this message to a different
 consumer.  If it is not possible or requeue is false, the message will be
@@ -162,9 +157,5 @@ Either Delivery.Ack, Delivery.Reject or Delivery.Nack must be called for every
 delivery that is not automatically acknowledged.
 */
 func (me Delivery) Nack(multiple, requeue bool) error {
-	return me.channel.send(me.channel, &basicNack{
-		DeliveryTag: me.DeliveryTag,
-		Multiple:    multiple,
-		Requeue:     requeue,
-	})
+	return me.Acknowledger.Nack(me.DeliveryTag, multiple, requeue)
 }