feat: scan existing systemd unit

We should scan existing systemd unit when we start application manager.
As application manager crash and restarted later,
we can get the launched application instances back.

apps/dde-application-manager/src/main.cpp

@@ -44,21 +44,7 @@ int main(int argc, char *argv[])
 
     registerComplexDbusType();
     ApplicationManager1Service AMService{std::make_unique<CGroupsIdentifier>(), AMBus};
-    QList<DesktopFile> fileList{};
-    const auto &desktopFileDirs = getDesktopFileDirs();
 
-    applyIteratively(QList<QDir>(desktopFileDirs.cbegin(), desktopFileDirs.cend()), [&AMService](const QFileInfo &info) -> bool {
-        DesktopErrorCode err{DesktopErrorCode::NoError};
-        auto ret = DesktopFile::searchDesktopFileByPath(info.absoluteFilePath(), err);
-        if (!ret.has_value()) {
-            qWarning() << "failed to search File:" << err;
-            return false;
-        }
-        if (!AMService.addApplication(std::move(ret).value())) {
-            qWarning() << "add Application failed, skip...";
-        }
-        return false;  // means to apply this function to the rest of the files
-    });
 #ifdef PROFILING_MODE
     auto end = std::chrono::high_resolution_clock::now();
     qCInfo(DDEAMProf) << std::chrono::duration_cast<std::chrono::milliseconds>(end - start).count() << "ms";

src/dbus/applicationmanager1service.cpp

@@ -7,6 +7,7 @@
 #include "dbus/AMobjectmanager1adaptor.h"
 #include "systemdsignaldispatcher.h"
 #include <QFile>
+#include <QDBusMessage>
 #include <unistd.h>
 
 ApplicationManager1Service::~ApplicationManager1Service() = default;
@@ -41,10 +42,21 @@ ApplicationManager1Service::ApplicationManager1Service(std::unique_ptr<Identifie
 
     auto &dispatcher = SystemdSignalDispatcher::instance();
 
+    connect(&dispatcher, &SystemdSignalDispatcher::SystemdUnitNew, this, &ApplicationManager1Service::addInstanceToApplication);
+
     connect(&dispatcher,
-            &SystemdSignalDispatcher::SystemdUnitNew,
+            &SystemdSignalDispatcher::SystemdUnitRemoved,
             this,
-            [this](const QString &unitName, const QDBusObjectPath &systemdUnitPath) {
+            &ApplicationManager1Service::removeInstanceFromApplication);
+
+    this->scanApplications();
+    this->scanInstances();
+
+    // TODO: send custom event;
+}
+
+void ApplicationManager1Service::addInstanceToApplication(const QString &unitName, const QDBusObjectPath &systemdUnitPath)
+{
     auto pair = processUnitName(unitName);
     auto appId = pair.first;
     auto instanceId = pair.second;
@@ -68,13 +80,11 @@ ApplicationManager1Service::ApplicationManager1Service(std::unique_ptr<Identifie
     }
 
     return;
-            });
+}
 
-    connect(&dispatcher,
-            &SystemdSignalDispatcher::SystemdUnitRemoved,
-            this,
-            [this](const QString &serviceName, QDBusObjectPath systemdUnitPath) {
-                auto pair = processUnitName(serviceName);
+void ApplicationManager1Service::removeInstanceFromApplication(const QString &unitName, const QDBusObjectPath &systemdUnitPath)
+{
+    auto pair = processUnitName(unitName);
     auto appId = pair.first;
     auto instanceId = pair.second;
     if (appId.isEmpty()) {
@@ -92,17 +102,54 @@ ApplicationManager1Service::ApplicationManager1Service(std::unique_ptr<Identifie
 
     const auto &appIns = (*appIt)->applicationInstances();
 
-                auto instanceIt = std::find_if(
-                    appIns.cbegin(), appIns.cend(), [&systemdUnitPath](const QSharedPointer<InstanceService> &value) {
+    auto instanceIt =
+        std::find_if(appIns.cbegin(), appIns.cend(), [&systemdUnitPath](const QSharedPointer<InstanceService> &value) {
             return value->systemdUnitPath() == systemdUnitPath;
         });
 
     if (instanceIt != appIns.cend()) [[likely]] {
         (*appIt)->removeOneInstance(instanceIt.key());
     }
+}
+
+void ApplicationManager1Service::scanApplications() noexcept
+{
+    QList<DesktopFile> fileList{};
+    const auto &desktopFileDirs = getDesktopFileDirs();
+
+    applyIteratively(QList<QDir>(desktopFileDirs.cbegin(), desktopFileDirs.cend()), [this](const QFileInfo &info) -> bool {
+        DesktopErrorCode err{DesktopErrorCode::NoError};
+        auto ret = DesktopFile::searchDesktopFileByPath(info.absoluteFilePath(), err);
+        if (!ret.has_value()) {
+            qWarning() << "failed to search File:" << err;
+            return false;
+        }
+        if (!this->addApplication(std::move(ret).value())) {
+            qWarning() << "add Application failed, skip...";
+        }
+        return false;  // means to apply this function to the rest of the files
     });
 }
 
+void ApplicationManager1Service::scanInstances() noexcept
+{
+    auto &conn = ApplicationManager1DBus::instance().globalDestBus();
+    auto call_message = QDBusMessage::createMethodCall(SystemdService, SystemdObjectPath, SystemdInterfaceName, "ListUnits");
+    auto result = conn.call(call_message);
+    if (result.type() == QDBusMessage::ErrorMessage) {
+        qCritical() << "failed to scan existing instances: call to ListUnits failed:" << result.errorMessage();
+        return;
+    }
+
+    auto v = result.arguments().first();
+    QList<SystemdUnitDBusMessage> units;
+    v.value<QDBusArgument>() >> units;
+    for (const auto &unit : units) {
+        // FIXME(black_desk): Should check this unit is active or not.
+        this->addInstanceToApplication(unit.name, unit.objectPath);
+    }
+}
+
 QList<QDBusObjectPath> ApplicationManager1Service::list() const
 {
     return m_applicationList.keys();

src/dbus/applicationmanager1service.h

@@ -53,6 +53,11 @@ private:
     std::unique_ptr<Identifier> m_identifier;
     QScopedPointer<JobManager1Service> m_jobManager{nullptr};
     QMap<QDBusObjectPath, QSharedPointer<ApplicationService>> m_applicationList;
+
+    void scanApplications() noexcept;
+    void scanInstances() noexcept;
+    void addInstanceToApplication(const QString &unitName, const QDBusObjectPath &systemdUnitPath);
+    void removeInstanceFromApplication(const QString &unitName, const QDBusObjectPath &systemdUnitPath);
 };
 
 #endif

src/global.h

@@ -17,6 +17,7 @@
 #include <QDir>
 #include <QRegularExpression>
 #include <QDBusObjectPath>
+#include <QDBusArgument>
 #include <unistd.h>
 #include <QUuid>
 #include <QLoggingCategory>
@@ -35,6 +36,30 @@ Q_DECLARE_METATYPE(ObjectInterfaceMap)
 Q_DECLARE_METATYPE(ObjectMap)
 Q_DECLARE_METATYPE(PropMap)
 
+struct SystemdUnitDBusMessage
+{
+    QString name;
+    QDBusObjectPath objectPath;
+};
+
+inline const QDBusArgument &operator>>(const QDBusArgument &argument, QList<SystemdUnitDBusMessage> &units)
+{
+    argument.beginArray();
+    while (!argument.atEnd()) {
+        argument.beginStructure();
+        QString _str;
+        uint32_t _uint;
+        QDBusObjectPath _path;
+        SystemdUnitDBusMessage unit;
+        argument >> unit.name >> _str >> _str >> _str >> _str >> _str >> unit.objectPath >> _uint >> _str >> _path;
+        units.push_back(unit);
+        argument.endStructure();
+    }
+    argument.endArray();
+
+    return argument;
+}
+
 inline QString getApplicationLauncherBinary()
 {
     static const QString bin = []() {
@@ -398,6 +423,7 @@ inline QStringList getAutoStartDirs()
 
 inline QPair<QString, QString> processUnitName(const QString &unitName)
 {
+    // FIXME: rewrite, using regexp.
     QString instanceId;
     QString applicationId;
 
@@ -417,10 +443,14 @@ inline QPair<QString, QString> processUnitName(const QString &unitName)
         auto app = unitName.sliced(0, lastDotIndex);
 
         auto components = app.split('-');
+        if (components.size() < 3) {
+            qDebug() << unitName << "is not a xdg application ignore";
+            return {};
+        }
         instanceId = components.takeLast();
         applicationId = components.takeLast();
     } else {
-        qDebug() << "it's not service or scope:" << unitName << "ignore.";
+        qDebug() << "it's not service or scope:" << unitName << "ignore";
         return {};
     }