Introduce synchronize merge method

* Create history-based merging that keeps older data in history instead of discarding or deleting it
* Extract merge logic into the Merger class
* Allows special merge behavior
* Improve handling of deletion and changes on groups
* Enable basic change tracking while merging
* Prevent unintended timestamp changes while merging
* Handle differences in timestamp precision
* Introduce comparison operators to allow for more sophisticated comparisons (ignore special properties, ...)
* Introduce Clock class to handle datetime across the app

Merge Strategies:
* Default (use inherited/fallback method)
* Duplicate (duplicate conflicting nodes, apply all deletions)
* KeepLocal (use local values, but apply all deletions)
* KeepRemote (use remote values, but apply all deletions)
* KeepNewer (merge history only)
* Synchronize (merge history, newest value stays on top, apply all deletions)

1 files changed, 38 insertions, 1 deletions

diff --git a/src/core/TimeInfo.cpp b/src/core/TimeInfo.cpp
index 85c53a567..c774a7c81 100644
--- a/src/core/TimeInfo.cpp
+++ b/src/core/TimeInfo.cpp
@@ -17,11 +17,13 @@
 
 #include "TimeInfo.h"
 
+#include "core/Clock.h"
+
 TimeInfo::TimeInfo()
     : m_expires(false)
     , m_usageCount(0)
 {
-    QDateTime now = QDateTime::currentDateTimeUtc();
+    QDateTime now = Clock::currentDateTimeUtc();
     m_lastModificationTime = now;
     m_creationTime = now;
     m_lastAccessTime = now;
@@ -103,3 +105,38 @@ void TimeInfo::setLocationChanged(const QDateTime& dateTime)
     Q_ASSERT(dateTime.timeSpec() == Qt::UTC);
     m_locationChanged = dateTime;
 }
+
+bool TimeInfo::operator==(const TimeInfo& other) const
+{
+    return equals(other, CompareItemDefault);
+}
+
+bool TimeInfo::operator!=(const TimeInfo& other) const
+{
+    return !this->operator==(other);
+}
+
+bool TimeInfo::equals(const TimeInfo& other, CompareItemOptions options) const
+{
+    if (::compare(m_lastModificationTime, other.m_lastModificationTime, options) != 0) {
+        return false;
+    }
+    if (::compare(m_creationTime, other.m_creationTime, options) != 0) {
+        return false;
+    }
+    if (::compare(!options.testFlag(CompareItemIgnoreStatistics), m_lastAccessTime, other.m_lastAccessTime, options)
+        != 0) {
+        return false;
+    }
+    if (::compare(m_expires, m_expiryTime, other.m_expires, other.expiryTime(), options) != 0) {
+        return false;
+    }
+    if (::compare(!options.testFlag(CompareItemIgnoreStatistics), m_usageCount, other.m_usageCount, options) != 0) {
+        return false;
+    }
+    if (::compare(!options.testFlag(CompareItemIgnoreLocation), m_locationChanged, other.m_locationChanged, options)
+        != 0) {
+        return false;
+    }
+    return true;
+}