Direct chat (un)marking: update internal structure synchronously

The asynchronous update first implemented was more verbose and caused
more problems than provided solutions. The idea was that the internal
directChats map would better reflect the server state if updated
asynchronously. However, it also causes a local race condition; e.g., to
quickly remove rooms from direct chats one after another becomes very
non-trivial (one has to wait until the previous operation succeeds). So
after some playing with the code, hitting pitfalls along the way, I
decided to align the logic with the one for room tags; synchronously
issued signals look uglyish but at least work predictably. And race
conditions between several clients generally cannot be cleanly resolved
anyway.

1 files changed, 11 insertions, 20 deletions

diff --git a/examples/qmc-example.cpp b/examples/qmc-example.cpp
index 5ea91856..23a1bff1 100644
--- a/examples/qmc-example.cpp
+++ b/examples/qmc-example.cpp
@@ -126,7 +126,8 @@ void QMCTest::addAndRemoveTag()
     if (targetRoom->tags().contains(TestTag))
         targetRoom->removeTag(TestTag);
 
-    QObject::connect(targetRoom, &Room::tagsChanged, targetRoom, [=] {
+    // Connect first because the signal is emitted synchronously.
+    connect(targetRoom, &Room::tagsChanged, targetRoom, [=] {
         cout << "Room " << targetRoom->id().toStdString()
              << ", tag(s) changed:" << endl
              << "  " << targetRoom->tagNames().join(", ").toStdString() << endl;
@@ -138,7 +139,6 @@ void QMCTest::addAndRemoveTag()
             QObject::disconnect(targetRoom, &Room::tagsChanged, nullptr, nullptr);
         }
     });
-    // The reverse order because tagsChanged is emitted synchronously.
     cout << "Adding a tag" << endl;
     targetRoom->addTag(TestTag);
 }
@@ -211,40 +211,31 @@ void QMCTest::checkRedactionOutcome(QString evtIdToRedact,
 
 void QMCTest::markDirectChat()
 {
-    if (c->isDirectChat(targetRoom))
+    if (c->isDirectChat(targetRoom->id()))
     {
         cout << "Warning: the room is already a direct chat,"
                 " only unmarking will be tested" << endl;
         checkDirectChatOutcome();
     }
-    cout << "Marking the room as a direct chat" << endl;
-    c->addToDirectChats(targetRoom, c->user());
+    // Connect first because the signal is emitted synchronously.
     connect(c.data(), &Connection::directChatsListChanged,
             this, &QMCTest::checkDirectChatOutcome);
+    cout << "Marking the room as a direct chat" << endl;
+    c->addToDirectChats(targetRoom, c->user());
 }
 
 void QMCTest::checkDirectChatOutcome()
 {
-    if (!c->isDirectChat(targetRoom))
+    disconnect(c.data(), &Connection::directChatsListChanged, nullptr, nullptr);
+    if (!c->isDirectChat(targetRoom->id()))
     {
-        cout << "Room not (yet?) added to direct chats, waiting" << endl;
+        QMC_CHECK("Direct chat test", false);
         return;
     }
 
     cout << "Room marked as a direct chat, unmarking now" << endl;
-    disconnect(c.data(), &Connection::directChatsListChanged, nullptr, nullptr);
-    c->removeFromDirectChats(targetRoom, c->user());
-    connect(c.data(), &Connection::directChatsListChanged, this, [this] {
-        if (c->isDirectChat(targetRoom))
-        {
-            cout << "Room not (yet?) removed from direct chats, waiting" << endl;
-            return;
-        }
-
-        QMC_CHECK("Direct chat test", !c->isDirectChat(targetRoom));
-        disconnect(c.data(), &Connection::directChatsListChanged,
-                   nullptr, nullptr);
-    });
+    c->removeFromDirectChats(targetRoom->id(), c->user());
+    QMC_CHECK("Direct chat test", !c->isDirectChat(targetRoom->id()));
 }
 
 void QMCTest::finalize()