flatpak: reuse the cancellable instances where it makes sense

It's not very useful to create the cancellable when we won't be able to
use it. Pass the one from the backend so we can cancel jobs upon closing
at least.

libdiscover/backends/FlatpakBackend/FlatpakBackend.cpp

@@ -480,7 +480,7 @@ FlatpakResource * FlatpakBackend::addAppFromFlatpakRef(const QUrl &url)
             }
             fw->deleteLater();
         });
-        fw->setFuture(QtConcurrent::run(&m_threadPool, &FlatpakRunnables::fetchMetadata, installation, resource));
+        fw->setFuture(QtConcurrent::run(&m_threadPool, &FlatpakRunnables::fetchMetadata, installation, resource, m_cancellable));
     } else {
         addResource(resource);
     }
@@ -980,7 +980,7 @@ bool FlatpakBackend::updateAppMetadata(FlatpakInstallation* flatpakInstallation,
                 onFetchMetadataFinished(flatpakInstallation, resource, metadata);
             fw->deleteLater();
         });
-        fw->setFuture(QtConcurrent::run(&m_threadPool, &FlatpakRunnables::fetchMetadata, flatpakInstallation, resource));
+        fw->setFuture(QtConcurrent::run(&m_threadPool, &FlatpakRunnables::fetchMetadata, flatpakInstallation, resource, m_cancellable));
 
         // Return false to indicate we cannot continue (right now used only in updateAppSize())
         return false;
@@ -1101,7 +1101,7 @@ bool FlatpakBackend::updateAppSizeFromRemote(FlatpakInstallation *flatpakInstall
         resource->setPropertyState(FlatpakResource::DownloadSize, FlatpakResource::Fetching);
         resource->setPropertyState(FlatpakResource::InstalledSize, FlatpakResource::Fetching);
 
-        futureWatcher->setFuture(QtConcurrent::run(&m_threadPool, &FlatpakRunnables::fetchFlatpakSize, flatpakInstallation, resource));
+        futureWatcher->setFuture(QtConcurrent::run(&m_threadPool, &FlatpakRunnables::fetchFlatpakSize, flatpakInstallation, resource, m_cancellable));
     }
 
     return true;

libdiscover/backends/FlatpakBackend/FlatpakFetchDataJob.cpp

@@ -27,9 +27,8 @@ static FlatpakRef * createFakeRef(FlatpakResource *resource)
 
 namespace FlatpakRunnables
 {
-QByteArray fetchMetadata(FlatpakInstallation *installation, FlatpakResource *app)
+QByteArray fetchMetadata(FlatpakInstallation *installation, FlatpakResource *app, GCancellable* cancellable)
 {
-    g_autoptr(GCancellable) cancellable = g_cancellable_new();
     g_autoptr(GError) localError = nullptr;
 
     if (app->origin().isEmpty()) {
@@ -61,9 +60,8 @@ QByteArray fetchMetadata(FlatpakInstallation *installation, FlatpakResource *app
     return metadataContent;
 }
 
-SizeInformation fetchFlatpakSize(FlatpakInstallation *installation, FlatpakResource *app)
+SizeInformation fetchFlatpakSize(FlatpakInstallation *installation, FlatpakResource *app, GCancellable* cancellable)
 {
-    g_autoptr(GCancellable) cancellable = g_cancellable_new();
     g_autoptr(GError) localError = nullptr;
 
     SizeInformation ret;

libdiscover/backends/FlatpakBackend/FlatpakFetchDataJob.h

@@ -23,9 +23,9 @@ namespace FlatpakRunnables
         guint64 installedSize;
     };
 
-    SizeInformation fetchFlatpakSize(FlatpakInstallation *installation, FlatpakResource *app);
+    SizeInformation fetchFlatpakSize(FlatpakInstallation *installation, FlatpakResource *app, GCancellable* cancellable);
 
-    QByteArray fetchMetadata(FlatpakInstallation *installation, FlatpakResource *app);
+    QByteArray fetchMetadata(FlatpakInstallation *installation, FlatpakResource *app, GCancellable* cancellable);
 }
 
 #endif // FLATPAKFETCHDATAJOB_H