From e1b40f54cb6409a686fce7cc881fda6f7638cc46 Mon Sep 17 00:00:00 2001
From: Mathew Sutcliffe <oktal3700@gmail.com>
Date: Tue, 2 Feb 2016 22:51:08 +0000
Subject: [PATCH] refs #581 Allow setting the timestamp when putting a value in
 the cache.

---
 src/blackmisc/datacache.h         | 2 +-
 src/blackmisc/valuecache.cpp      | 7 ++++---
 src/blackmisc/valuecache.h        | 4 ++--
 src/blackmisc/valuecacheprivate.h | 2 +-
 4 files changed, 8 insertions(+), 7 deletions(-)

diff --git a/src/blackmisc/datacache.h b/src/blackmisc/datacache.h
index 023d2ce10..08455f271 100644
--- a/src/blackmisc/datacache.h
+++ b/src/blackmisc/datacache.h
@@ -178,7 +178,7 @@ namespace BlackMisc
         QString getFilename() const { return CDataCache::filenameForKey(this->getKey()); }
 
         //! Data cache doesn't support setAndSave (because set() already causes save anyway).
-        CStatusMessage setAndSave(const typename Trait::type &value) = delete;
+        CStatusMessage setAndSave(const typename Trait::type &value, qint64 timestamp = 0) = delete;
     };
 
     /*!
diff --git a/src/blackmisc/valuecache.cpp b/src/blackmisc/valuecache.cpp
index 17b1329d5..5d0265195 100644
--- a/src/blackmisc/valuecache.cpp
+++ b/src/blackmisc/valuecache.cpp
@@ -410,11 +410,12 @@ namespace BlackMisc
         return element.m_value.read();
     }
 
-    CStatusMessage CValuePage::setValue(Element &element, const CVariant &value, bool save)
+    CStatusMessage CValuePage::setValue(Element &element, const CVariant &value, qint64 timestamp, bool save)
     {
         Q_ASSERT(QThread::currentThread() == thread());
 
-        if (element.m_value.read() == value) { return {}; }
+        if (timestamp == 0) { timestamp = QDateTime::currentMSecsSinceEpoch(); }
+        if (element.m_value.read() == value && element.m_timestamp == timestamp) { return {}; }
 
         auto error = validate(element, value);
         if (error.isEmpty())
@@ -430,7 +431,7 @@ namespace BlackMisc
                 element.m_saved = save;
 
                 element.m_value.uniqueWrite() = value;
-                emit valuesWantToCache({ { { element.m_key, value } }, QDateTime::currentMSecsSinceEpoch(), save });
+                emit valuesWantToCache({ { { element.m_key, value } }, timestamp, save });
             }
         }
         else
diff --git a/src/blackmisc/valuecache.h b/src/blackmisc/valuecache.h
index dec46533d..5b96e12ce 100644
--- a/src/blackmisc/valuecache.h
+++ b/src/blackmisc/valuecache.h
@@ -279,10 +279,10 @@ namespace BlackMisc
         const T &get() const { static const T empty {}; return *(isValid() ? static_cast<const T *>(getVariant().data()) : &empty); }
 
         //! Write a new value. Must be called from the thread in which the owner lives.
-        CStatusMessage set(const T &value) { return m_page.setValue(m_element, CVariant::from(value)); }
+        CStatusMessage set(const T &value, qint64 timestamp = 0) { return m_page.setValue(m_element, CVariant::from(value), timestamp); }
 
         //! Write and save in the same step. Must be called from the thread in which the owner lives.
-        CStatusMessage setAndSave(const T &value) { return m_page.setValue(m_element, CVariant::from(value), true); }
+        CStatusMessage setAndSave(const T &value, qint64 timestamp = 0) { return m_page.setValue(m_element, CVariant::from(value), timestamp, true); }
 
         //! Get the key string of this value.
         const QString &getKey() const { return m_page.getKey(m_element); }
diff --git a/src/blackmisc/valuecacheprivate.h b/src/blackmisc/valuecacheprivate.h
index 255b4efec..533aa3ac9 100644
--- a/src/blackmisc/valuecacheprivate.h
+++ b/src/blackmisc/valuecacheprivate.h
@@ -62,7 +62,7 @@ namespace BlackMisc
             const CVariant &getValue(const Element &element) const;
 
             //! Write the value corresponding to the element's key and begin synchronizing it to any other pages.
-            CStatusMessage setValue(Element &element, const CVariant &value, bool save = false);
+            CStatusMessage setValue(Element &element, const CVariant &value, qint64 timestamp, bool save = false);
 
             //! Get the key string corresponding to the element.
             const QString &getKey(const Element &element) const;