Reverse direct chats map

Speeds up lookup of user(s) in a direct chat room.

Also: "The other one's"  avatar is used to set the avatar of direct
chats only, not any room with 2 participants.

6 files changed, 47 insertions, 32 deletions

diff --git a/lib/connection.cpp b/lib/connection.cpp
index fcd73d04..29c044f1 100644
--- a/lib/connection.cpp
+++ b/lib/connection.cpp
@@ -89,6 +89,7 @@ class Connection::Private
         QVector<Room*> firstTimeRooms;
         QMap<QString, User*> userMap;
         DirectChatsMap directChats;
+        DirectChatUsersMap directChatUsers;
         std::unordered_map<QString, EventPtr> accountData;
         QString userId;
 
@@ -356,6 +357,9 @@ void Connection::onSyncSuccess(SyncData &&data) {
                 erase_if(d->directChats, [&usersToDCs] (auto it) {
                     return !usersToDCs.contains(it.key()->id(), it.value());
                 });
+            erase_if(d->directChatUsers, [&usersToDCs] (auto it) {
+                return !usersToDCs.contains(it.value()->id(), it.key());
+            });
             if (MAIN().isDebugEnabled())
                 for (auto it = removals.begin(); it != removals.end(); ++it)
                     qCDebug(MAIN) << it.value()
@@ -364,12 +368,14 @@ void Connection::onSyncSuccess(SyncData &&data) {
             DirectChatsMap additions;
             for (auto it = usersToDCs.begin(); it != usersToDCs.end(); ++it)
             {
-                if (const auto* u = user(it.key()))
+                if (auto* u = user(it.key()))
                 {
                     if (!d->directChats.contains(u, it.value()))
                     {
+                        Q_ASSERT(!d->directChatUsers.contains(it.value(), u));
                         additions.insert(u, it.value());
                         d->directChats.insert(u, it.value());
+                        d->directChatUsers.insert(it.value(), u);
                         qCDebug(MAIN) << "Marked room" << it.value()
                                       << "as a direct chat with" << u->id();
                     }
@@ -520,7 +526,7 @@ CreateRoomJob* Connection::createRoom(RoomVisibility visibility,
 
 void Connection::requestDirectChat(const QString& userId)
 {
-    if (const auto* u = user(userId))
+    if (auto* u = user(userId))
         requestDirectChat(u);
     else
         qCCritical(MAIN)
@@ -528,7 +534,7 @@ void Connection::requestDirectChat(const QString& userId)
             << userId;
 }
 
-void Connection::requestDirectChat(const User* u)
+void Connection::requestDirectChat(User* u)
 {
     doInDirectChat(u, [this] (Room* r) { emit directChatAvailable(r); });
 }
@@ -536,7 +542,7 @@ void Connection::requestDirectChat(const User* u)
 void Connection::doInDirectChat(const QString& userId,
                                 const std::function<void(Room*)>& operation)
 {
-    if (const auto* u = user(userId))
+    if (auto* u = user(userId))
         doInDirectChat(u, operation);
     else
         qCCritical(MAIN)
@@ -544,7 +550,7 @@ void Connection::doInDirectChat(const QString& userId,
             << userId;
 }
 
-void Connection::doInDirectChat(const User* u,
+void Connection::doInDirectChat(User* u,
                                 const std::function<void(Room*)>& operation)
 {
     Q_ASSERT(u);
@@ -591,7 +597,10 @@ void Connection::doInDirectChat(const User* u,
     if (!removals.isEmpty())
     {
         for (auto it = removals.cbegin(); it != removals.cend(); ++it)
+        {
             d->directChats.remove(it.key(), it.value());
+            d->directChatUsers.remove(it.value(), it.key());
+        }
         d->broadcastDirectChatUpdates({}, removals);
     }
 
@@ -871,17 +880,19 @@ void Connection::Private::broadcastDirectChatUpdates(const DirectChatsMap& addit
     emit q->directChatsListChanged(additions, removals);
 }
 
-void Connection::addToDirectChats(const Room* room, const User* user)
+void Connection::addToDirectChats(const Room* room, User* user)
 {
     Q_ASSERT(room != nullptr && user != nullptr);
     if (d->directChats.contains(user, room->id()))
         return;
+    Q_ASSERT(!d->directChatUsers.contains(room->id(), user));
     d->directChats.insert(user, room->id());
+    d->directChatUsers.insert(room->id(), user);
     DirectChatsMap additions { { user, room->id() } };
     d->broadcastDirectChatUpdates(additions, {});
 }
 
-void Connection::removeFromDirectChats(const QString& roomId, const User* user)
+void Connection::removeFromDirectChats(const QString& roomId, User* user)
 {
     Q_ASSERT(!roomId.isEmpty());
     if ((user != nullptr && !d->directChats.contains(user, roomId)) ||
@@ -893,22 +904,24 @@ void Connection::removeFromDirectChats(const QString& roomId, const User* user)
     {
         removals.insert(user, roomId);
         d->directChats.remove(user, roomId);
-    }
-    else
+        d->directChatUsers.remove(roomId, user);
+    } else {
         removals = erase_if(d->directChats,
                             [&roomId] (auto it) { return it.value() == roomId; });
+        d->directChatUsers.remove(roomId);
+    }
     d->broadcastDirectChatUpdates({}, removals);
 }
 
 bool Connection::isDirectChat(const QString& roomId) const
 {
-    return d->directChats.key(roomId) != nullptr;
+    return d->directChatUsers.contains(roomId);
 }
 
-QList<const User*> Connection::directChatUsers(const Room* room) const
+QList<User*> Connection::directChatUsers(const Room* room) const
 {
     Q_ASSERT(room != nullptr);
-    return d->directChats.keys(room->id());
+    return d->directChatUsers.values(room->id());
 }
 
 bool Connection::isIgnored(const User* user) const
diff --git a/lib/connection.h b/lib/connection.h
index e761acfd..9b253711 100644
--- a/lib/connection.h
+++ b/lib/connection.h
@@ -94,7 +94,12 @@ namespace QMatrixClient
             using user_factory_t =
                 std::function<User*(Connection*, const QString&)>;
 
+            // Room ids, rather than room pointers, are used in the direct chat
+            // map types because the library keeps Invite rooms separate from
+            // rooms in Join and Leave state; and direct chats in account data
+            // are stored with no regard to their state.
             using DirectChatsMap = QMultiHash<const User*, QString>;
+            using DirectChatUsersMap = QMultiHash<QString, User*>;
             using IgnoredUsersList = IgnoredUsersEvent::content_type;
 
             using UsersToDevicesToEvents =
@@ -171,7 +176,7 @@ namespace QMatrixClient
              *
              * \sa directChatsListChanged
              */
-            void addToDirectChats(const Room* room, const User* user);
+            void addToDirectChats(const Room* room, User* user);
 
             /** Unmark the room from direct chats
              * This function removes the room id from direct chats either for
@@ -184,7 +189,7 @@ namespace QMatrixClient
              * \sa directChatsListChanged
              */
             void removeFromDirectChats(const QString& roomId,
-                                       const User* user = nullptr);
+                                       User* user = nullptr);
 
             /** Check whether the room id corresponds to a direct chat */
             bool isDirectChat(const QString& roomId) const;
@@ -196,7 +201,7 @@ namespace QMatrixClient
              * @return The list of users for which this room is marked as
              * a direct chat; an empty list if the room is not a direct chat
              */
-            QList<const User*> directChatUsers(const Room* room) const;
+            QList<User*> directChatUsers(const Room* room) const;
 
             /** Check whether a particular user is in the ignore list */
             bool isIgnored(const User* user) const;
@@ -392,7 +397,7 @@ namespace QMatrixClient
              *
              * \sa directChatAvailable
              */
-            void requestDirectChat(const User* u);
+            void requestDirectChat(User* u);
 
             /** Run an operation in a direct chat with the user
              * This method may return synchronously or asynchoronously depending
@@ -409,7 +414,7 @@ namespace QMatrixClient
              * already. Instead of emitting a signal it executes the passed
              * function object with the direct chat room as its parameter.
              */
-            void doInDirectChat(const User* u,
+            void doInDirectChat(User* u,
                                 const std::function<void(Room*)>& operation);
 
             /** Create a direct chat with a single user, optional name and topic
diff --git a/lib/room.cpp b/lib/room.cpp
index 27f54ddb..91fb6831 100644
--- a/lib/room.cpp
+++ b/lib/room.cpp
@@ -332,15 +332,12 @@ QImage Room::avatar(int width, int height)
         return d->avatar.get(connection(), width, height,
                              [=] { emit avatarChanged(); });
 
-    // Use the other side's avatar for 1:1's
-    if (d->membersMap.size() == 2)
-    {
-        auto theOtherOneIt = d->membersMap.begin();
-        if (theOtherOneIt.value() == localUser())
-            ++theOtherOneIt;
-        return (*theOtherOneIt)->avatar(width, height, this,
-                                        [=] { emit avatarChanged(); });
-    }
+    // Use the first (excluding self) user's avatar for direct chats
+    const auto dcUsers = directChatUsers();
+    for (auto* u: dcUsers)
+        if (u != localUser())
+            return u->avatar(width, height, this, [=] { emit avatarChanged(); });
+
     return {};
 }
 
@@ -760,7 +757,7 @@ bool Room::isDirectChat() const
     return connection()->isDirectChat(id());
 }
 
-QList<const User*> Room::directChatUsers() const
+QList<User*> Room::directChatUsers() const
 {
     return connection()->directChatUsers(this);
 }
diff --git a/lib/room.h b/lib/room.h
index 35263eaf..8e56c37a 100644
--- a/lib/room.h
+++ b/lib/room.h
@@ -285,7 +285,7 @@ namespace QMatrixClient
             Q_INVOKABLE bool isDirectChat() const;
 
             /** Get the list of users this room is a direct chat with */
-            QList<const User*> directChatUsers() const;
+            QList<User*> directChatUsers() const;
 
             Q_INVOKABLE QUrl urlToThumbnail(const QString& eventId);
             Q_INVOKABLE QUrl urlToDownload(const QString& eventId);
diff --git a/lib/user.cpp b/lib/user.cpp
index 12977b8a..b9f493c5 100644
--- a/lib/user.cpp
+++ b/lib/user.cpp
@@ -299,7 +299,7 @@ bool User::setAvatar(QIODevice* source)
                 std::bind(&Private::setAvatarOnServer, d.data(), _1, this));
 }
 
-void User::requestDirectChat() const
+void User::requestDirectChat()
 {
     connection()->requestDirectChat(this);
 }
@@ -356,7 +356,7 @@ QImage User::avatar(int width, int height, const Room* room)
 }
 
 QImage User::avatar(int width, int height, const Room* room,
-                    Avatar::get_callback_t callback)
+                    const Avatar::get_callback_t& callback)
 {
     return avatarObject(room).get(d->connection, width, height,
                 [=] { emit avatarChanged(this, room); callback(); });
diff --git a/lib/user.h b/lib/user.h
index c33ed028..17f5625f 100644
--- a/lib/user.h
+++ b/lib/user.h
@@ -100,7 +100,7 @@ namespace QMatrixClient
             Q_INVOKABLE QImage avatar(int requestedWidth, int requestedHeight,
                                       const Room* room = nullptr);
             QImage avatar(int width, int height, const Room* room,
-                          Avatar::get_callback_t callback);
+                          const Avatar::get_callback_t& callback);
 
             QString avatarMediaId(const Room* room = nullptr) const;
             QUrl avatarUrl(const Room* room = nullptr) const;
@@ -120,7 +120,7 @@ namespace QMatrixClient
              * The resulting chat is returned asynchronously via
              * Connection::directChatAvailable()
              */
-            void requestDirectChat() const;
+            void requestDirectChat();
             /** Add the user to the ignore list */
             void ignore();
             /** Remove the user from the ignore list */