refs #695 Allow to set a mock root directory for caches, for unit tests.

src/blackmisc/valuecache.h

@@ -48,6 +48,13 @@ namespace BlackMisc
 {
     class CLogCategoryList;
 
+    /*!
+     * Overwrite the default root directory for cache and settings, for testing purposes.
+     *
+     * May not be called after any cache or settings objects have been constructed.
+     */
+    BLACKMISC_EXPORT void setMockCacheRootDirectory(const QString &path);
+
     /*!
      * Value class used for signalling changed values in the cache.
      */
@@ -280,6 +287,9 @@ namespace BlackMisc
         //! \threadsafe
         qint64 getTimestampSync(const QString &key) { return std::get<1>(getValue(key)); }
 
+        //! \private
+        static const QString &getCacheRootDirectory();
+
     private:
         friend class Private::CValuePage;
         struct Element;