From a4dfc4ba9d3c90cd1b8fe9c7249dc8f02a068d95 Mon Sep 17 00:00:00 2001
From: Mathew Sutcliffe <oktal3700@gmail.com>
Date: Sun, 18 Oct 2015 22:26:23 +0100
Subject: [PATCH] refs #494 Use QFileSystemWatcher to watch for remote changes
 to the data store.

---
 src/blackcore/datacache.cpp | 5 +++--
 src/blackcore/datacache.h   | 4 ++--
 2 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/src/blackcore/datacache.cpp b/src/blackcore/datacache.cpp
index 5f71af7fe..852afced1 100644
--- a/src/blackcore/datacache.cpp
+++ b/src/blackcore/datacache.cpp
@@ -27,9 +27,10 @@ namespace BlackCore
         }
 
         connect(this, &CValueCache::valuesChangedByLocal, this, &CDataCache::saveToStore);
+        connect(&m_watcher, &QFileSystemWatcher::fileChanged, this, [this] { loadFromStore(); });
 
-        connect(&m_reloadTimer, &QTimer::timeout, this, [this]() { loadFromStore(); });
-        m_reloadTimer.start(1000);
+        if (! QFile::exists(m_revisionFileName)) { QFile(m_revisionFileName).open(QFile::WriteOnly); }
+        m_watcher.addPath(m_revisionFileName);
         loadFromStore();
     }
 
diff --git a/src/blackcore/datacache.h b/src/blackcore/datacache.h
index 9957c139d..c87d16b2c 100644
--- a/src/blackcore/datacache.h
+++ b/src/blackcore/datacache.h
@@ -15,7 +15,7 @@
 #include "blackcore/blackcoreexport.h"
 #include "blackmisc/valuecache.h"
 #include <QUuid>
-#include <QTimer>
+#include <QFileSystemWatcher>
 
 namespace BlackCore
 {
@@ -46,7 +46,7 @@ namespace BlackCore
         //! \param defer Whether to defer applying the changes. Used when called by saveToStore.
         void loadFromStore(bool lock = true, bool defer = false);
 
-        QTimer m_reloadTimer;
+        QFileSystemWatcher m_watcher;
         QUuid m_revision;
         const QString m_revisionFileName { persistentStore() + "/.rev" };
         BlackMisc::CVariantMap m_deferredChanges;