Fetch all dependencies in a single transaction

PackageKit would choke on big updates otherwise

libdiscover/backends/PackageKitBackend/PackageKitBackend.cpp

@@ -515,9 +515,29 @@ void PackageKitBackend::fetchDetails(const QString& pkgid)
 void PackageKitBackend::performDetailsFetch()
 {
     Q_ASSERT(!m_packageNamesToFetchDetails.isEmpty());
-    PackageKit::Transaction* transaction = PackageKit::Daemon::getDetails(m_packageNamesToFetchDetails.toList());
+    const auto ids = m_packageNamesToFetchDetails.toList();
+
+    PackageKit::Transaction* transaction = PackageKit::Daemon::getDetails(ids);
     connect(transaction, &PackageKit::Transaction::details, this, &PackageKitBackend::packageDetails);
     connect(transaction, &PackageKit::Transaction::errorCode, this, &PackageKitBackend::transactionError);
+
+    QSharedPointer<QMap<QString, int>> packageDependencies(new QMap<QString, int>);
+    auto trans = PackageKit::Daemon::installPackages(ids, PackageKit::Transaction::TransactionFlagSimulate);
+    connect(trans, &PackageKit::Transaction::errorCode, this, &PackageKitBackend::transactionError);
+    connect(trans, &PackageKit::Transaction::package, this, [packageDependencies](PackageKit::Transaction::Info /*info*/, const QString &packageID, const QString &/*summary*/) {
+        (*packageDependencies)[packageID] += 1;
+    });
+    connect(trans, &PackageKit::Transaction::finished, this, [this, packageDependencies](PackageKit::Transaction::Exit /*status*/) {
+        auto pkgDeps = (*packageDependencies);
+
+        for (auto it = pkgDeps.constBegin(), itEnd = pkgDeps.constEnd(); it != itEnd; ++it) {
+            const auto resources = resourcesByPackageName(PackageKit::Daemon::packageName(it.key()));
+            for(auto resource : resources) {
+                auto pkres = qobject_cast<PackageKitResource*>(resource);
+                pkres->setDependenciesCount(it.value());
+            }
+        }
+    });
 }
 
 void PackageKitBackend::checkDaemonRunning()

libdiscover/backends/PackageKitBackend/PackageKitResource.cpp

@@ -169,18 +169,6 @@ void PackageKitResource::fetchDetails()
     m_details.insert(QStringLiteral("fetching"), true);//we add an entry so it's not re-fetched.
 
     backend()->fetchDetails(pkgid);
-
-    auto trans = PackageKit::Daemon::installPackages({ pkgid }, PackageKit::Transaction::TransactionFlagSimulate);
-    connect(trans, &PackageKit::Transaction::package, this, [trans](PackageKit::Transaction::Info /*info*/, const QString &/*packageID*/, const QString &/*summary*/) {
-        trans->setProperty("dependencies", trans->property("dependencies").toUInt() + 1);
-    });
-    connect(trans, &PackageKit::Transaction::finished, this, [this, trans](PackageKit::Transaction::Exit /*status*/) {
-        auto deps = trans->property("dependencies").toUInt();
-        if (deps != m_dependenciesCount) {
-            m_dependenciesCount = deps;
-            Q_EMIT sizeChanged();
-        }
-    });
 }
 
 void PackageKitResource::failedFetchingDetails(PackageKit::Transaction::Error, const QString& msg)
@@ -188,6 +176,14 @@ void PackageKitResource::failedFetchingDetails(PackageKit::Transaction::Error, c
     qWarning() << "error fetching details" << msg;
 }
 
+void PackageKitResource::setDependenciesCount(uint deps)
+{
+    if (deps != m_dependenciesCount) {
+        m_dependenciesCount = deps;
+        Q_EMIT sizeChanged();
+    }
+}
+
 void PackageKitResource::setDetails(const PackageKit::Details & details)
 {
     const bool ourDetails = details.packageId() == availablePackageId();

libdiscover/backends/PackageKitBackend/PackageKitResource.h

@@ -67,6 +67,7 @@ class PackageKitResource : public AbstractResource
         bool canExecute() const override { return false; }
 
         QString sizeDescription() override;
+        void setDependenciesCount(uint count);
 
     public Q_SLOTS:
         void addPackageId(PackageKit::Transaction::Info info, const QString &packageId, bool arch);