refs #545 CValueCache keeps track of which values have been saved.

src/blackmisc/datacache.cpp

@@ -16,7 +16,7 @@
 namespace BlackMisc
 {
     CDataCache::CDataCache() :
-        CValueCache(CValueCache::LocalOnly) // for signal loopback
+        CValueCache(CValueCache::Distributed)
     {
         if (! QDir::root().mkpath(persistentStore()))
         {
@@ -24,6 +24,11 @@ namespace BlackMisc
         }
 
         connect(this, &CValueCache::valuesChangedByLocal, this, &CDataCache::saveToStoreAsync);
+        connect(this, &CValueCache::valuesChangedByLocal, this, [ = ](CValueCachePacket values)
+        {
+            values.setSaved();
+            changeValuesFromRemote(values, CIdentifier());
+        });
         connect(&m_watcher, &QFileSystemWatcher::fileChanged, this, &CDataCache::loadFromStoreAsync);
         connect(&m_serializer, &CDataCacheSerializer::valuesLoadedFromStore, this, &CDataCache::changeValuesFromRemote);
 
@@ -127,6 +132,7 @@ namespace BlackMisc
 
         if (! m_deferredChanges.isEmpty()) // apply changes which we grabbed at the last minute above
         {
+            m_deferredChanges.setSaved();
             emit valuesLoadedFromStore(m_deferredChanges, CIdentifier::anonymous());
             m_deferredChanges.clear();
         }
@@ -163,6 +169,7 @@ namespace BlackMisc
 
         if (! (m_deferredChanges.isEmpty() || defer))
         {
+            m_deferredChanges.setSaved();
             emit valuesLoadedFromStore(m_deferredChanges, CIdentifier::anonymous());
             m_deferredChanges.clear();
         }

src/blackmisc/settingscache.cpp

@@ -28,7 +28,7 @@ namespace BlackMisc
         return dir;
     }
 
-    BlackMisc::CStatusMessage CSettingsCache::saveToStore(const QString &keyPrefix) const
+    BlackMisc::CStatusMessage CSettingsCache::saveToStore(const QString &keyPrefix)
     {
         return saveToFiles(persistentStore(), keyPrefix);
     }

src/blackmisc/settingscache.h

@@ -32,7 +32,7 @@ namespace BlackMisc
         static const QString &persistentStore();
 
         //! Save core settings to disk.
-        BlackMisc::CStatusMessage saveToStore(const QString &keyPrefix = {}) const;
+        BlackMisc::CStatusMessage saveToStore(const QString &keyPrefix = {});
 
         //! Load core settings from disk.
         BlackMisc::CStatusMessage loadFromStore();

src/blackmisc/valuecache.cpp

@@ -29,7 +29,8 @@ namespace BlackMisc
     // CValueCachePacket
     ////////////////////////////////
 
-    CValueCachePacket::CValueCachePacket(const CVariantMap &values, qint64 timestamp)
+    CValueCachePacket::CValueCachePacket(const CVariantMap &values, qint64 timestamp, bool saved) :
+        m_saved(saved)
     {
         for (auto it = values.cbegin(); it != values.cend(); ++it)
         {
@@ -89,6 +90,7 @@ namespace BlackMisc
         const QString m_key;
         CVariant m_value;
         int m_pendingChanges = 0;
+        bool m_saved = false;
         std::atomic<qint64> m_timestamp { QDateTime::currentMSecsSinceEpoch() };
     };
 
@@ -156,6 +158,7 @@ namespace BlackMisc
             element.m_pendingChanges++;
             element.m_value = in.value();
             element.m_timestamp = in.timestamp();
+            element.m_saved = values.isSaved();
         }
         emit valuesChanged(values, sender());
         emit valuesChangedByLocal(values);
@@ -182,6 +185,7 @@ namespace BlackMisc
             {
                 element.m_value = in.value();
                 element.m_timestamp = in.timestamp();
+                element.m_saved = values.isSaved();
                 ratifiedChanges.insert(in.key(), in.value(), in.timestamp());
             }
         }
@@ -203,11 +207,13 @@ namespace BlackMisc
         insertValues({ map, QDateTime::currentMSecsSinceEpoch() });
     }
 
-    CStatusMessage CValueCache::saveToFiles(const QString &dir, const QString &keyPrefix) const
+    CStatusMessage CValueCache::saveToFiles(const QString &dir, const QString &keyPrefix)
     {
         QMutexLocker lock(&m_mutex);
         auto values = getAllValues(keyPrefix);
-        return saveToFiles(dir, values);
+        auto status = saveToFiles(dir, values);
+        if (! status.isEmpty()) { markAllAsSaved(keyPrefix); }
+        return status;
     }
 
     CStatusMessage CValueCache::saveToFiles(const QString &dir, const CVariantMap &values) const
@@ -250,6 +256,7 @@ namespace BlackMisc
         QMutexLocker lock(&m_mutex);
         CValueCachePacket values;
         auto status = loadFromFiles(dir, getAllValues(), values);
+        values.setSaved();
         insertValues(values);
         return status;
     }
@@ -280,6 +287,15 @@ namespace BlackMisc
         return {};
     }
 
+    void CValueCache::markAllAsSaved(const QString &keyPrefix)
+    {
+        QMutexLocker lock(&m_mutex);
+        for (const auto &element : elementsStartingWith(keyPrefix))
+        {
+            element->m_saved = true;
+        }
+    }
+
     QString CValueCache::filenameForKey(const QString &key)
     {
         return key.section('/', 0, 0) + ".json";

src/blackmisc/valuecache.h

@@ -23,14 +23,29 @@ namespace BlackMisc
      */
     class BLACKMISC_EXPORT CValueCachePacket :
         public CDictionary<QString, std::pair<CVariant, qint64>, QMap>,
-        public Mixin::MetaType<CValueCachePacket>
+        public Mixin::MetaType<CValueCachePacket>,
+        public Mixin::DBusByTuple<CValueCachePacket>,
+        public Mixin::JsonByTuple<CValueCachePacket>,
+        public Mixin::EqualsByTuple<CValueCachePacket>
     {
     public:
-        //! Default constructor.
-        CValueCachePacket() {}
+        BLACKMISC_DECLARE_USING_MIXIN_DBUS(CValueCachePacket)
+        BLACKMISC_DECLARE_USING_MIXIN_JSON(CValueCachePacket)
+
+        //! \copydoc BlackMisc::CValueObject::base_type
+        using base_type = CDictionary;
+
+        //! Constructor.
+        CValueCachePacket(bool saved = false) : m_saved(saved) {}
 
         //! Construct from CVariantMap and a timestamp.
-        CValueCachePacket(const CVariantMap &values, qint64 timestamp);
+        CValueCachePacket(const CVariantMap &values, qint64 timestamp, bool saved = false);
+
+        //! Values are to be saved.
+        //! @{
+        bool isSaved() const { return m_saved; }
+        void setSaved(bool saved = true) { m_saved = saved; }
+        //! @}
 
         //! Insert a key/value pair with a timestamp.
         void insert(const QString &key, const CVariant &value, qint64 timestamp);
@@ -67,6 +82,10 @@ namespace BlackMisc
         const_iterator begin() const { return CDictionary::cbegin(); }
         const_iterator end() const { return CDictionary::cend(); }
         //! @}
+
+    private:
+        BLACK_ENABLE_TUPLE_CONVERSION(CValueCachePacket)
+        bool m_saved = false;
     };
 
     /*!
@@ -118,7 +137,7 @@ namespace BlackMisc
         //! Save values to Json files in a given directory.
         //! If prefix is provided then only those values whose keys start with that prefix.
         //! \threadsafe
-        CStatusMessage saveToFiles(const QString &directory, const QString &keyPrefix = {}) const;
+        CStatusMessage saveToFiles(const QString &directory, const QString &keyPrefix = {});
 
         //! Load all values from Json files in a given directory.
         //! Values already in the cache will remain in the cache unless they are overwritten.
@@ -186,6 +205,10 @@ namespace BlackMisc
         //! \threadsafe
         CStatusMessage loadFromFiles(const QString &directory, const CVariantMap &current, CValueCachePacket &o_values) const;
 
+        //! Mark all values with keys that start with the given prefix as having been saved.
+        //! \threadsafe
+        void markAllAsSaved(const QString &keyPrefix);
+
         //! Mutex protecting operations which are critical on m_elements.
         mutable QMutex m_mutex { QMutex::Recursive };
 
@@ -308,5 +331,6 @@ namespace BlackMisc
 } // namespace
 
 Q_DECLARE_METATYPE(BlackMisc::CValueCachePacket)
+BLACK_DECLARE_TUPLE_CONVERSION(BlackMisc::CValueCachePacket, (attr(o.m_saved)))
 
 #endif