String optimizations

Author: AdrianTM

mainwindow.cpp

@@ -89,13 +89,10 @@ MainWindow::MainWindow(QWidget *parent)
     });
     connect(ui->listServices, &QListWidget::itemEntered, this, [this](QListWidgetItem *item) {
         if (auto service = item->data(Qt::UserRole).value<Service *>()) {
-            ui->listServices->blockSignals(true);
             if (item->toolTip().isEmpty()) {
-                ui->lineSearch->blockSignals(true);
-                item->setToolTip(service->getDescription());
-                ui->lineSearch->blockSignals(false);
+                const QString description = service->getDescription();
+                item->setToolTip(description);
             }
-            ui->listServices->blockSignals(false);
         }
     });
 }
@@ -199,16 +196,25 @@ void MainWindow::processNonSystemdServices()
     const auto list = cmd.getOut("/sbin/service --status-all", true).trimmed().split("\n");
     QRegularExpression re("dpkg-.*$");
     services.reserve(list.size());
+
+    const QLatin1String sectionDelimiter("]  ");
+    const QLatin1String debian("debian");
+    const QLatin1String runningPrefix("[ + ]");
+
     for (const auto &item : list) {
-        if (item.trimmed().contains(re) || item.section("]  ", 1) == "debian") {
+        const QString trimmedItem = item.trimmed();
+        if (trimmedItem.contains(re) || item.section(sectionDelimiter, 1) == debian) {
             continue;
         }
-        QString name = item.section("]  ", 1);
+
+        const QString name = item.section(sectionDelimiter, 1);
         if (name.isEmpty()) {
             continue;
         }
-        services.append(QSharedPointer<Service>::create(name, item.trimmed().startsWith("[ + ]")));
-        services.last()->setEnabled(Service::isEnabled(name) || dependTargets.contains(name));
+
+        auto service = QSharedPointer<Service>::create(name, trimmedItem.startsWith(runningPrefix));
+        service->setEnabled(dependTargets.contains(name) || Service::isEnabled(name));
+        services.append(std::move(service));
     }
 }
 
@@ -230,29 +236,39 @@ void MainWindow::processSystemdActiveInactiveServices(QStringList &names)
     }
 
     auto jsonArray = doc.array();
-    names.reserve(jsonArray.size() * 2);
 
     QSet<QString> nameSet(names.begin(), names.end());
     services.reserve(services.size() + jsonArray.size());
+    nameSet.reserve(nameSet.size() + jsonArray.size());
+
+    const QLatin1String unitKey("unit");
+    const QLatin1String loadKey("load");
+    const QLatin1String subKey("sub");
+    const QLatin1String dotSeparator(".");
+    const QLatin1String notFoundValue("not-found");
+    const QLatin1String runningValue("running");
 
     for (const auto &value : jsonArray) {
         if (!value.isObject()) {
             continue;
         }
-        auto obj = value.toObject();
-        QString name = obj.value("unit").toString().section('.', 0, 0);
 
-        if (name.isEmpty() || nameSet.contains(name) || obj.value("load").toString() == "not-found") {
+        const auto obj = value.toObject();
+        const QString name = obj.value(unitKey).toString().section(dotSeparator, 0, 0);
+
+        if (name.isEmpty() || nameSet.contains(name)
+            || obj.value(loadKey).toString() == notFoundValue) {
             continue;
         }
 
         nameSet.insert(name);
 
-        bool isRunning = (obj.value("sub").toString() == "running");
-        bool isEnabled = Service::isEnabled(name) || dependTargets.contains(name);
+        const bool isRunning = (obj.value(subKey).toString() == runningValue);
+        const bool isEnabled = dependTargets.contains(name) || Service::isEnabled(name);
 
-        services.append(QSharedPointer<Service>::create(name, isRunning));
-        services.last()->setEnabled(isEnabled);
+        auto service = QSharedPointer<Service>::create(name, isRunning);
+        service->setEnabled(isEnabled);
+        services.append(std::move(service));
     }
     names = QStringList(nameSet.begin(), nameSet.end());
 }
@@ -270,19 +286,23 @@ void MainWindow::processSystemdMaskedServices(QStringList &names)
     auto jsonArray = doc.array();
     QSet<QString> nameSet(names.begin(), names.end());
     services.reserve(services.size() + jsonArray.size());
+    nameSet.reserve(nameSet.size() + jsonArray.size());
+
+    const QLatin1String unitFileKey("unit_file");
+    const QLatin1String dotSeparator(".");
 
     for (const auto &value : jsonArray) {
         if (!value.isObject()) {
             continue;
         }
-        auto obj = value.toObject();
-        QString name = obj.value("unit_file").toString().section('.', 0, 0);
+        const auto obj = value.toObject();
+        const QString name = obj.value(unitFileKey).toString().section(dotSeparator, 0, 0);
 
         if (name.isEmpty() || nameSet.contains(name)) {
             continue;
         }
-
         nameSet.insert(name);
+
         auto service = QSharedPointer<Service>::create(name, false);
         service->setEnabled(false);
         services.append(std::move(service));

service.cpp

@@ -58,12 +58,14 @@ QString Service::getInfo() const
 
 bool Service::isEnabled(const QString &name)
 {
-    if (initSystem == "systemd") {
-        return (QProcess::execute("systemctl", {"-q", "is-enabled", name}) == 0);
+    if (initSystem == QLatin1String("systemd")) {
+        return QProcess::execute(QLatin1String("systemctl"),
+                                 {QLatin1String("-q"), QLatin1String("is-enabled"), name + QLatin1String(".service")})
+               == 0;
     } else {
-        return (
-            QProcess::execute("/bin/bash", {"-c", QString("[[ -e /etc/rc5.d/S*%1 || -e /etc/rcS.d/S*%1 ]]").arg(name)})
-            == 0);
+        // Check both runlevel 5 (multi-user with GUI) and runlevel S (single-user/boot)
+        QString command = QString(QLatin1String("[[ -e /etc/rc5.d/S*%1 || -e /etc/rcS.d/S*%1 ]]")).arg(name);
+        return QProcess::execute(QLatin1String("/bin/bash"), {QLatin1String("-c"), command}) == 0;
     }
 }
 
@@ -160,7 +162,7 @@ void Service::setRunning(bool running)
 QString Service::getInfoFromFile(const QString &name)
 {
     // Check for the service file in standard locations
-    QStringList possiblePaths = {"/etc/init.d/" + name, "/etc/init.d/" + name + ".sh"};
+    const QStringList possiblePaths = {"/etc/init.d/" + name, "/etc/init.d/" + name + ".sh"};
 
     QString filePath;
     for (const auto &path : possiblePaths) {
@@ -176,26 +178,32 @@ QString Service::getInfoFromFile(const QString &name)
     }
 
     QFile file(filePath);
-    if (!file.open(QIODevice::ReadOnly)) {
+    if (!file.open(QIODevice::ReadOnly | QIODevice::Text)) {
         qDebug() << "Could not open file" << filePath;
         return Cmd().getOut("/sbin/service " + name + " status", false, false, true);
     }
 
     QString info;
+    info.reserve(1024); // Pre-allocate memory to avoid reallocations
     bool info_header = false;
 
-    while (!file.atEnd()) {
-        QString line = file.readLine().trimmed();
+    QTextStream in(&file);
+    while (!in.atEnd()) {
+        QString line = in.readLine().trimmed();
+
+        if (line.startsWith("### BEGIN INIT INFO")) {
+            info_header = true;
+            continue;
+        }
+
         if (line.startsWith("### END INIT INFO")) {
-            info_header = false;
+            break; // No need to read the rest of the file
         }
+
         if (info_header) {
             line.remove(0, 2);
             info.append(line + '\n');
         }
-        if (line.startsWith("### BEGIN INIT INFO")) {
-            info_header = true;
-        }
     }
 
     return info;