add support for cancelling a consumer

cancel method and cancelled signal added to Queue, added auto tests
to guarantee conditions surrounding the cancel process

src/amqp_queue.cpp

@@ -66,6 +66,9 @@ bool QueuePrivate::_q_method(const Frame::Method &frame)
         case bmGetEmpty:
             Q_EMIT q->empty();
             break;
+        case bmCancelOk:
+            cancelOk(frame);
+            break;
         }
 
         return true;
@@ -240,6 +243,21 @@ void QueuePrivate::declare()
         delayedDeclare = false;
 }
 
+void QueuePrivate::cancelOk(const Frame::Method &frame)
+{
+    Q_Q(Queue);
+    qAmqpDebug() << Q_FUNC_INFO;
+    QByteArray data = frame.arguments();
+    QDataStream in(&data, QIODevice::ReadOnly);
+    QString consumer = Frame::readField('s',in).toString();
+    if (consumerTag != consumer) {
+        qAmqpDebug() << Q_FUNC_INFO << "invalid consumer tag: " << consumer;
+        return;
+    }
+
+    consumerTag.clear();
+    Q_EMIT q->cancelled(consumer);
+}
 
 //////////////////////////////////////////////////////////////////////////
 
@@ -506,3 +524,30 @@ void Queue::ack(const Message &message)
     frame.setArguments(arguments);
     d->sendFrame(frame);
 }
+
+bool Queue::cancel(bool noWait)
+{
+    Q_D(Queue);
+    if (!d->consuming) {
+        qAmqpDebug() << Q_FUNC_INFO << "not consuming!";
+        return false;
+    }
+
+    if (d->consumerTag.isEmpty()) {
+        qAmqpDebug() << Q_FUNC_INFO << "consuming with an empty consumer tag, failing...";
+        return false;
+    }
+
+    Frame::Method frame(Frame::fcBasic, QueuePrivate::bmCancel);
+    frame.setChannel(d->channelNumber);
+
+    QByteArray arguments;
+    QDataStream out(&arguments, QIODevice::WriteOnly);
+
+    Frame::writeField('s', out, d->consumerTag);
+    out << (noWait ? qint8(0x01) : qint8(0x0));
+
+    frame.setArguments(arguments);
+    d->sendFrame(frame);
+    return true;
+}

src/amqp_queue.h

@@ -76,6 +76,7 @@ public:
     bool consume(int options = NoOptions);
     void get();
     void ack(const Message &message);
+    bool cancel(bool noWait = false);
 
 Q_SIGNALS:
     void declared();
@@ -86,6 +87,7 @@ Q_SIGNALS:
     void empty();
     void purged(int messageCount);
     void consuming(const QString &consumerTag);
+    void cancelled(const QString &consumerTag);
 
 protected:
     // reimp Channel

src/amqp_queue_p.h

@@ -26,19 +26,22 @@ public:
     ~QueuePrivate();
 
     void declare();
-
-    // method handler related
     virtual bool _q_method(const Frame::Method &frame);
-    virtual void _q_content(const Frame::Content &frame);
-    virtual void _q_body(const Frame::ContentBody &frame);
+
+    // AMQP Queue method handlers
     void declareOk(const Frame::Method &frame);
     void deleteOk(const Frame::Method &frame);
     void purgeOk(const Frame::Method &frame);
     void bindOk(const Frame::Method &frame);
     void unbindOk(const Frame::Method &frame);
-    void getOk(const Frame::Method &frame);
     void consumeOk(const Frame::Method &frame);
+
+    // AMQP Basic method handlers
+    virtual void _q_content(const Frame::Content &frame);
+    virtual void _q_body(const Frame::ContentBody &frame);
     void deliver(const Frame::Method &frame);
+    void getOk(const Frame::Method &frame);
+    void cancelOk(const Frame::Method &frame);
 
     QString type;
     int options;

tests/auto/qamqpqueue/tst_qamqpqueue.cpp

@@ -31,6 +31,9 @@ private Q_SLOTS:
     void unbind();
     void purge();
     void canOnlyStartConsumingOnce();
+    void cancel();
+    void invalidCancelBecauseNotConsuming();
+    void invalidCancelBecauseInvalidConsumerTag();
 
 private:
     QScopedPointer<Client> client;
@@ -310,10 +313,57 @@ void tst_QAMQPQueue::canOnlyStartConsumingOnce()
     QSignalSpy spy(queue, SIGNAL(consuming(QString)));
     QVERIFY(waitForSignal(queue, SIGNAL(consuming(QString))));
     QVERIFY(queue->isConsuming());
+    QVERIFY(!spy.isEmpty());
     QList<QVariant> arguments = spy.takeFirst();
     QCOMPARE(arguments.at(0).toString(), queue->consumerTag());
     QCOMPARE(queue->consume(), false);
 }
 
+void tst_QAMQPQueue::cancel()
+{
+    Queue *queue = client->createQueue("test-cancel");
+    queue->declare();
+    QVERIFY(waitForSignal(queue, SIGNAL(declared())));
+    QVERIFY(queue->consume());
+    QSignalSpy spy(queue, SIGNAL(consuming(QString)));
+    QVERIFY(waitForSignal(queue, SIGNAL(consuming(QString))));
+    QVERIFY(queue->isConsuming());
+    QVERIFY(!spy.isEmpty());
+    QList<QVariant> arguments = spy.takeFirst();
+    QCOMPARE(arguments.at(0).toString(), queue->consumerTag());
+
+    QString consumerTag = queue->consumerTag();
+    QSignalSpy cancelSpy(queue, SIGNAL(cancelled(QString)));
+    QVERIFY(queue->cancel());
+    QVERIFY(waitForSignal(queue, SIGNAL(cancelled(QString))));
+    QVERIFY(!cancelSpy.isEmpty());
+    arguments = cancelSpy.takeFirst();
+    QCOMPARE(arguments.at(0).toString(), consumerTag);
+}
+
+void tst_QAMQPQueue::invalidCancelBecauseNotConsuming()
+{
+    Queue *queue = client->createQueue("test-invalid-cancel-because-not-consuming");
+    queue->declare();
+    QVERIFY(waitForSignal(queue, SIGNAL(declared())));
+    QCOMPARE(queue->cancel(), false);
+}
+
+void tst_QAMQPQueue::invalidCancelBecauseInvalidConsumerTag()
+{
+    Queue *queue = client->createQueue("test-invalid-cancel-because-invalid-consumer-tag");
+    queue->declare();
+    QVERIFY(waitForSignal(queue, SIGNAL(declared())));
+    QVERIFY(queue->consume());
+    QSignalSpy spy(queue, SIGNAL(consuming(QString)));
+    QVERIFY(waitForSignal(queue, SIGNAL(consuming(QString))));
+    QVERIFY(queue->isConsuming());
+    QVERIFY(!spy.isEmpty());
+    QList<QVariant> arguments = spy.takeFirst();
+    QCOMPARE(arguments.at(0).toString(), queue->consumerTag());
+    queue->setConsumerTag(QString());
+    QCOMPARE(queue->cancel(), false);
+}
+
 QTEST_MAIN(tst_QAMQPQueue)
 #include "tst_qamqpqueue.moc"