Add const to TransactionalSettings class functions

src/base/settingsstorage.cpp

@@ -51,16 +51,16 @@ namespace
         {
         }
 
-        QVariantHash read();
-        bool write(const QVariantHash &data);
+        QVariantHash read() const;
+        bool write(const QVariantHash &data) const;
 
     private:
         // we return actual file names used by QSettings because
         // there is no other way to get that name except
         // actually create a QSettings object.
         // if serialization operation was not successful we return empty string
-        QString deserialize(const QString &name, QVariantHash &data);
-        QString serialize(const QString &name, const QVariantHash &data);
+        QString deserialize(const QString &name, QVariantHash &data) const;
+        QString serialize(const QString &name, const QVariantHash &data) const;
 
         const QString m_name;
     };
@@ -187,10 +187,10 @@ SettingsStorage *SettingsStorage::instance()
 bool SettingsStorage::save()
 {
     if (!m_dirty) return false; // Obtaining the lock is expensive, let's check early
-    QWriteLocker locker(&m_lock);
+    const QWriteLocker locker(&m_lock);
     if (!m_dirty) return false; // something might have changed while we were getting the lock
 
-    TransactionalSettings settings(QLatin1String("qBittorrent"));
+    const TransactionalSettings settings(QLatin1String("qBittorrent"));
     if (settings.write(m_data)) {
         m_dirty = false;
         return true;
@@ -229,7 +229,7 @@ void SettingsStorage::removeValue(const QString &key)
     }
 }
 
-QVariantHash TransactionalSettings::read()
+QVariantHash TransactionalSettings::read() const
 {
     QVariantHash res;
 
@@ -257,7 +257,7 @@ QVariantHash TransactionalSettings::read()
     return res;
 }
 
-bool TransactionalSettings::write(const QVariantHash &data)
+bool TransactionalSettings::write(const QVariantHash &data) const
 {
     // QSettings deletes the file before writing it out. This can result in problems
     // if the disk is full or a power outage occurs. Those events might occur
@@ -278,7 +278,7 @@ bool TransactionalSettings::write(const QVariantHash &data)
     return QFile::rename(newPath, finalPath);
 }
 
-QString TransactionalSettings::deserialize(const QString &name, QVariantHash &data)
+QString TransactionalSettings::deserialize(const QString &name, QVariantHash &data) const
 {
     SettingsPtr settings = Profile::instance().applicationSettings(name);
 
@@ -294,7 +294,7 @@ QString TransactionalSettings::deserialize(const QString &name, QVariantHash &da
     return settings->fileName();
 }
 
-QString TransactionalSettings::serialize(const QString &name, const QVariantHash &data)
+QString TransactionalSettings::serialize(const QString &name, const QVariantHash &data) const
 {
     SettingsPtr settings = Profile::instance().applicationSettings(name);
     for (auto i = data.begin(); i != data.end(); ++i)