Remove deleted transport objects

Added a QMultiHash which maps transport objects to wrapped object ids.
transportRemoved iterates over all matching wrapped objects and removes
the passed transport object from their transports-vector. If the
transports-vector is empty after removing the passed transport object
the objectDestroyed will be called on the wrapped object.
transportRemoved will be called either on the transports destoryed
signal or on disconnecting the webchannel from it.

Without this changes the QMetaObjectPublisher::wrappedObjects and
::registeredObjectIds would only be cleaned up if the website calls
deleteLater on QObjects but not on website reloads.

Task-number: QTBUG-50074
Change-Id: If294564fee2406edd7fb578852aeb269cac23a92
Reviewed-by: Milian Wolff <milian.wolff@kdab.com>

2 files changed, 55 insertions, 0 deletions

diff --git a/tests/auto/webchannel/tst_webchannel.cpp b/tests/auto/webchannel/tst_webchannel.cpp
index 7e8e5f5..9531c6f 100644
--- a/tests/auto/webchannel/tst_webchannel.cpp
+++ b/tests/auto/webchannel/tst_webchannel.cpp
@@ -455,6 +455,28 @@ void TestWebChannel::testWrapRegisteredObject()
     QCOMPARE(obj.objectName(), returnedId);
 }
 
+void TestWebChannel::testRemoveUnusedTransports()
+{
+    QWebChannel channel;
+    DummyTransport *dummyTransport = new DummyTransport(this);
+    TestObject obj;
+
+    channel.connectTo(dummyTransport);
+    channel.d_func()->publisher->initializeClient(dummyTransport);
+
+    QMetaObjectPublisher *pub = channel.d_func()->publisher;
+    pub->wrapResult(QVariant::fromValue(&obj), dummyTransport);
+
+    QCOMPARE(pub->wrappedObjects.size(), 1);
+    QCOMPARE(pub->registeredObjectIds.size(), 1);
+
+    channel.disconnectFrom(dummyTransport);
+    delete dummyTransport;
+
+    QCOMPARE(pub->wrappedObjects.size(), 0);
+    QCOMPARE(pub->registeredObjectIds.size(), 0);
+}
+
 void TestWebChannel::testInfiniteRecursion()
 {
     QWebChannel channel;
@@ -550,6 +572,37 @@ void TestWebChannel::benchRegisterObjects()
         channel.registerObjects(objects);
     }
 }
+
+void TestWebChannel::benchRemoveTransport()
+{
+    QWebChannel channel;
+    QList<DummyTransport*> dummyTransports;
+    for (int i = 500; i > 0; i--)
+        dummyTransports.append(new DummyTransport(this));
+
+    QList<QSharedPointer<TestObject>> objs;
+    QMetaObjectPublisher *pub = channel.d_func()->publisher;
+
+    foreach (DummyTransport *transport, dummyTransports) {
+        channel.connectTo(transport);
+        channel.d_func()->publisher->initializeClient(transport);
+
+        /* 30 objects per transport */
+        for (int i = 30; i > 0; i--) {
+            QSharedPointer<TestObject> obj = QSharedPointer<TestObject>::create();
+            objs.append(obj);
+            pub->wrapResult(QVariant::fromValue(obj.data()), transport);
+        }
+    }
+
+    QBENCHMARK_ONCE {
+        for (auto transport : dummyTransports)
+            pub->transportRemoved(transport);
+    }
+
+    qDeleteAll(dummyTransports);
+}
+
 #ifdef WEBCHANNEL_TESTS_CAN_USE_JS_ENGINE
 
 class SubclassedTestObject : public TestObject
diff --git a/tests/auto/webchannel/tst_webchannel.h b/tests/auto/webchannel/tst_webchannel.h
index 98733dc..0d2fe55 100644
--- a/tests/auto/webchannel/tst_webchannel.h
+++ b/tests/auto/webchannel/tst_webchannel.h
@@ -232,12 +232,14 @@ private slots:
     void testInvokeMethodConversion();
     void testDisconnect();
     void testWrapRegisteredObject();
+    void testRemoveUnusedTransports();
     void testInfiniteRecursion();
 
     void benchClassInfo();
     void benchInitializeClients();
     void benchPropertyUpdates();
     void benchRegisterObjects();
+    void benchRemoveTransport();
 
     void qtbug46548_overriddenProperties();