Share bounded thumbnail workers and keep PM downloads in DM transport

tools/chatgui/src/messagelist.cpp

@@ -965,23 +965,27 @@ void MessageList::onAttachmentDownloaded(const QString& chId, int64_t msgId) {
         }
     }
 
-    if (m.contentType == "video/mp4") {
-        QString fp = item->data(MsgVoiceFileRole).toString();
-        QString thumbPath = fp + ".jpg";
-        if (!fp.isEmpty() && QFile::exists(fp) && !QFile::exists(thumbPath)) {
-            QPointer<MessageList> self(this);
-            std::thread([self, fp, thumbPath]() {
-                int rc = video_extract_thumbnail(fp.toUtf8().constData(),
-                                                 thumbPath.toUtf8().constData(), 320);
-                DEBUG_DEBUG(DEBUG_CATEGORY_VIDEO, "MessageList: thumbnail %s rc=%d",
-                            qPrintable(thumbPath), rc);
-                if (self) {
-                    QMetaObject::invokeMethod(self, [self]() { self->m_view->viewport()->update(); },
-                                              Qt::QueuedConnection);
-                }
-            }).detach();
-        }
-    }
+    if (m.contentType == "video/mp4") prepareVideoThumbnail(item->data(MsgVoiceFileRole).toString());
+}
+
+/* Общие превью для каналов/PM; не более двух decoder workers, без запуска из paint. */
+void MessageList::prepareVideoThumbnail(const QString& path) {
+    if (path.isEmpty() || m_thumbnailJobs.contains(path) || !QFile::exists(path) || QFile::exists(path + ".jpg")) return;
+    m_thumbnailPool.setMaxThreadCount(2);
+    m_thumbnailJobs.insert(path);
+    QPointer<MessageList> self(this);
+    QObject* dispatcher = QCoreApplication::instance();
+    m_thumbnailPool.start([self, dispatcher, path]() {
+        QString output = path + ".jpg";
+        int rc = video_extract_thumbnail(path.toUtf8().constData(), output.toUtf8().constData(), 320);
+        if (rc) DEBUG_WARN(DEBUG_CATEGORY_VIDEO, "thumbnail failed path=%s error=%d", qPrintable(path), rc);
+        else DEBUG_DEBUG(DEBUG_CATEGORY_VIDEO, "thumbnail ready path=%s", qPrintable(output));
+        QMetaObject::invokeMethod(dispatcher, [self, path]() {
+            if (!self) return;
+            self->m_thumbnailJobs.remove(path);
+            self->m_view->viewport()->update();
+        }, Qt::QueuedConnection);
+    });
 }
 
 void MessageList::onMessageContextMenu(const QPoint& pos) {
@@ -992,6 +996,7 @@ void MessageList::onMessageContextMenu(const QPoint& pos) {
     bool isVideo = (ct == "video/mp4");
     bool isImage = ct.startsWith("image/");
     bool isDmFile = isDmChannel(idx.data(MsgChannelIdRole).toString()) && ct == "application/octet-stream";
+    bool isDm = isDmChannel(idx.data(MsgChannelIdRole).toString());
     if (!isVideo && !isImage && !isDmFile) return;
 
     QString filePath = idx.data(MsgVoiceFileRole).toString();
@@ -1002,7 +1007,7 @@ void MessageList::onMessageContextMenu(const QPoint& pos) {
     QAction* saveAct = menu.addAction(QString::fromUtf8("Сохранить в файл"));
     saveAct->setEnabled(downloaded);
     QAction* dlAct = nullptr;
-    if (!downloaded && !isDmFile) dlAct = menu.addAction(QString::fromUtf8("Скачать"));
+    if (!downloaded && !isDm) dlAct = menu.addAction(QString::fromUtf8("Скачать"));
 
     QAction* chosen = menu.exec(m_view->viewport()->mapToGlobal(pos));
 
@@ -1137,6 +1142,7 @@ void MessageList::onDmMessages(const uint8_t* data, int len) {
                 item->setData(duration, MsgVideoDurationMsRole);
                 item->setData(message.value("width").toInt(), MsgVideoWidthRole);
                 item->setData(message.value("height").toInt(), MsgVideoHeightRole);
+                prepareVideoThumbnail(path);
             }
         }
         m_model->appendRow(item);