fix(offlinemsg): make faux offline messages purely event based

Since real offline message reliability issue was fixed in PR #4607, now removing all the workarounds that had been added. Offline messages are now sent as soon as we see our friend come online, and at no other time. Fixes 2 minute wait time before attempting to send if message is entered while you or friend is offline, removes 2 minute constant retry timer, removes 250ms delay between seeing friend come online and sending offline messages.

src/persistence/offlinemsgengine.cpp

@@ -27,28 +27,12 @@
 #include <QTimer>
 #include <QCoreApplication>
 
-/**
- * @var static const int OfflineMsgEngine::offlineTimeout
- * @brief timeout after which faux offline messages get to be re-sent.
- * Originally was 2s, but since that was causing lots of duplicated
- * messages on receiving end, make qTox be more lazy about re-sending
- * should be 20s.
- */
-
-
-const int OfflineMsgEngine::offlineTimeout = 20000;
-QMutex OfflineMsgEngine::globalMutex;
-
 OfflineMsgEngine::OfflineMsgEngine(Friend* frnd)
     : mutex(QMutex::Recursive)
     , f(frnd)
 {
 }
 
-OfflineMsgEngine::~OfflineMsgEngine()
-{
-}
-
 void OfflineMsgEngine::dischargeReceipt(int receipt)
 {
     QMutexLocker ml(&mutex);
@@ -63,8 +47,7 @@ void OfflineMsgEngine::dischargeReceipt(int receipt)
     processReceipt(receipt);
 }
 
-void OfflineMsgEngine::registerReceipt(int receipt, int64_t messageID, ChatMessage::Ptr msg,
-                                       const QDateTime& timestamp)
+void OfflineMsgEngine::registerReceipt(int receipt, int64_t messageID, ChatMessage::Ptr msg)
 {
     QMutexLocker ml(&mutex);
 
@@ -76,7 +59,7 @@ void OfflineMsgEngine::registerReceipt(int receipt, int64_t messageID, ChatMessa
     }
     it->rowId = messageID;
     it->bRowValid = true;
-    undeliveredMsgs[messageID] = {msg, timestamp, receipt};
+    undeliveredMsgs[messageID] = {msg, receipt};
     processReceipt(receipt);
 }
 
@@ -100,11 +83,6 @@ void OfflineMsgEngine::deliverOfflineMsgs()
     for (auto iter = msgs.begin(); iter != msgs.end(); ++iter) {
         auto val = iter.value();
         auto key = iter.key();
-
-        if (val.timestamp.msecsTo(QDateTime::currentDateTime()) < offlineTimeout) {
-            registerReceipt(val.receipt, key, val.msg, val.timestamp);
-            continue;
-        }
         QString messageText = val.msg->toString();
         int rec;
         if (val.msg->isAction()) {

src/persistence/offlinemsgengine.h

@@ -28,22 +28,19 @@
 #include <QSet>
 
 class Friend;
-class QTimer;
 
 class OfflineMsgEngine : public QObject
 {
     Q_OBJECT
 public:
     explicit OfflineMsgEngine(Friend*);
-    virtual ~OfflineMsgEngine();
-    static QMutex globalMutex;
+    virtual ~OfflineMsgEngine() = default;
 
     void dischargeReceipt(int receipt);
-    void registerReceipt(int receipt, int64_t messageID, ChatMessage::Ptr msg,
-                         const QDateTime& timestamp = QDateTime::currentDateTime());
+    void registerReceipt(int receipt, int64_t messageID, ChatMessage::Ptr msg);
+    void deliverOfflineMsgs();
 
 public slots:
-    void deliverOfflineMsgs();
     void removeAllReceipts();
     void updateTimestamp(int receiptId);
 
@@ -59,7 +56,6 @@ public slots:
     struct MsgPtr
     {
         ChatMessage::Ptr msg;
-        QDateTime timestamp;
         int receipt;
     };
     QMutex mutex;

src/widget/form/chatform.cpp

@@ -64,7 +64,6 @@
  */
 
 static const int CHAT_WIDGET_MIN_HEIGHT = 50;
-static const int DELIVER_OFFLINE_MESSAGES_DELAY = 250;
 static const int SCREENSHOT_GRABBER_OPENING_DELAY = 500;
 static const int TYPING_NOTIFICATION_DURATION = 3000;
 
@@ -559,7 +558,7 @@ void ChatForm::onFriendStatusChanged(uint32_t friendId, Status status)
         // Hide the "is typing" message when a friend goes offline
         setFriendTyping(false);
     } else {
-        QTimer::singleShot(DELIVER_OFFLINE_MESSAGES_DELAY, this, SLOT(onDeliverOfflineMessages()));
+        offlineEngine->deliverOfflineMsgs();
     }
 
     updateCallButtons();
@@ -695,11 +694,6 @@ void ChatForm::clearChatArea(bool notInForm)
     offlineEngine->removeAllReceipts();
 }
 
-void ChatForm::onDeliverOfflineMessages()
-{
-    offlineEngine->deliverOfflineMsgs();
-}
-
 void ChatForm::onLoadChatHistory()
 {
     if (sender() == f) {

src/widget/form/chatform.h

@@ -82,7 +82,6 @@ private slots:
     void onAttachClicked() override;
     void onScreenshotClicked() override;
 
-    void onDeliverOfflineMessages();
     void onLoadChatHistory();
     void onTextEditChanged();
     void onCallTriggered();

src/widget/widget.cpp

@@ -112,9 +112,6 @@ void Widget::init()
 
     timer = new QTimer();
     timer->start(1000);
-    offlineMsgTimer = new QTimer();
-    // FIXME: ↓ make a proper fix instead of increasing timeout into ∞
-    offlineMsgTimer->start(2 * 60 * 1000);
 
     icon_size = 15;
 
@@ -259,7 +256,6 @@ void Widget::init()
     connect(timer, &QTimer::timeout, this, &Widget::onUserAwayCheck);
     connect(timer, &QTimer::timeout, this, &Widget::onEventIconTick);
     connect(timer, &QTimer::timeout, this, &Widget::onTryCreateTrayIcon);
-    connect(offlineMsgTimer, &QTimer::timeout, this, &Widget::processOfflineMsgs);
     connect(ui->searchContactText, &QLineEdit::textChanged, this, &Widget::searchContacts);
     connect(filterGroup, &QActionGroup::triggered, this, &Widget::searchContacts);
     connect(filterDisplayGroup, &QActionGroup::triggered, this, &Widget::changeDisplayMode);
@@ -537,7 +533,6 @@ Widget::~Widget()
     delete groupInviteForm;
     delete filesForm;
     delete timer;
-    delete offlineMsgTimer;
     delete contentLayout;
 
     FriendList::clear();
@@ -2180,18 +2175,6 @@ bool Widget::filterOnline(FilterCriteria index)
     }
 }
 
-void Widget::processOfflineMsgs()
-{
-    if (OfflineMsgEngine::globalMutex.tryLock()) {
-        QList<Friend*> frnds = FriendList::getAllFriends();
-        for (Friend* f : frnds) {
-            chatForms[f->getId()]->getOfflineMsgEngine()->deliverOfflineMsgs();
-        }
-
-        OfflineMsgEngine::globalMutex.unlock();
-    }
-}
-
 void Widget::clearAllReceipts()
 {
     QList<Friend*> frnds = FriendList::getAllFriends();

src/widget/widget.h

@@ -212,7 +212,6 @@ private slots:
     void onTryCreateTrayIcon();
     void onSetShowSystemTray(bool newValue);
     void onSplitterMoved(int pos, int index);
-    void processOfflineMsgs();
     void friendListContextMenu(const QPoint& pos);
     void friendRequestsUpdate();
     void groupInvitesUpdate();
@@ -293,7 +292,7 @@ private slots:
     MaskablePixmapWidget* profilePicture;
     bool notify(QObject* receiver, QEvent* event);
     bool autoAwayActive = false;
-    QTimer *timer, *offlineMsgTimer;
+    QTimer *timer;
     QRegExp nameMention, sanitizedNameMention;
     bool eventFlag;
     bool eventIcon;