Create an LRU cache for linkpreviewers

Create an LRU cache for linkpreviewers to stop the storage growing continuously as new links are made.

src/neochatconnection.cpp

@@ -9,7 +9,6 @@
 #include "controller.h"
 #include "jobs/neochatchangepasswordjob.h"
 #include "jobs/neochatdeactivateaccountjob.h"
-#include "linkpreviewer.h"
 #include "neochatconfig.h"
 #include "neochatroom.h"
 #include "notificationsmanager.h"
@@ -45,6 +44,7 @@ NeoChatConnection::NeoChatConnection(QObject *parent)
     : Connection(parent)
     , m_threePIdModel(new ThreePIdModel(this))
 {
+    m_linkPreviewers.setMaxCost(20);
     connectSignals();
 }
 
@@ -52,6 +52,7 @@ NeoChatConnection::NeoChatConnection(const QUrl &server, QObject *parent)
     : Connection(server, parent)
     , m_threePIdModel(new ThreePIdModel(this))
 {
+    m_linkPreviewers.setMaxCost(20);
     connectSignals();
 }
 
@@ -563,13 +564,13 @@ LinkPreviewer *NeoChatConnection::previewerForLink(const QUrl &link)
         return nullptr;
     }
 
-    auto previewer = m_linkPreviewers.value(link, nullptr);
+    auto previewer = m_linkPreviewers.object(link);
     if (previewer != nullptr) {
         return previewer;
     }
 
     previewer = new LinkPreviewer(link, this);
-    m_linkPreviewers[link] = previewer;
+    m_linkPreviewers.insert(link, previewer);
     return previewer;
 }
 

src/neochatconnection.h

@@ -3,6 +3,7 @@
 
 #pragma once
 
+#include <QCache>
 #include <QObject>
 #include <QQmlEngine>
 
@@ -13,10 +14,9 @@
 #include <Quotient/keyimport.h>
 #endif
 
+#include "linkpreviewer.h"
 #include "models/threepidmodel.h"
 
-class LinkPreviewer;
-
 class NeoChatConnection : public Quotient::Connection
 {
     Q_OBJECT
@@ -222,7 +222,7 @@ private:
 
     int m_badgeNotificationCount = 0;
 
-    QHash<QUrl, LinkPreviewer *> m_linkPreviewers;
+    QCache<QUrl, LinkPreviewer> m_linkPreviewers;
 
     bool m_canCheckMutualRooms = false;
 };