Change object version to timestamps for diff updates on config sync

fixes #10257

lib/base/configobject.cpp

@@ -223,7 +223,7 @@ void ConfigObject::ModifyAttribute(const String& attr, const Value& value, bool
 	SetField(fid, newValue);
 
 	if (updateVersion)
-		SetVersion(GetVersion() + 1);
+		SetVersion(Utility::GetTime());
 
 	if (updated_original_attributes)
 		NotifyOriginalAttributes();
@@ -341,11 +341,7 @@ void ConfigObject::RestoreAttribute(const String& attr)
 	original_attributes->Remove(attr);
 	SetField(fid, newValue);
 
-	/* increment the version. although restoring would mean
-	 * decrementing the version, but we cannot notify other
-	 * cluster nodes without increment.
-	 */
-	SetVersion(GetVersion() + 1);
+	SetVersion(Utility::GetTime());
 }
 
 bool ConfigObject::IsAttributeModified(const String& attr) const
@@ -638,7 +634,6 @@ void ConfigObject::DumpModifiedAttributes(const boost::function<void(const Confi
 			ObjectLock olock(originalAttributes);
 			BOOST_FOREACH(const Dictionary::Pair& kv, originalAttributes) {
 				String key = kv.first;
-				// TODO-MA: vars.os
 
 				Type::Ptr type = object->GetReflectionType();
 

lib/base/configobject.ti

@@ -95,7 +95,7 @@ abstract class ConfigObject : ConfigObjectBase
 	[protected] bool state_loaded;
 	Dictionary::Ptr original_attributes;
 	[state] int version {
-		default {{{ return 1; }}}
+		default {{{ return 0; }}}
 	};
 };
 

lib/remote/apilistener-configsync.cpp

@@ -392,6 +392,15 @@ void ApiListener::SendRuntimeConfigObjects(const JsonRpcConnection::Ptr& aclient
 			if (objZone.IsEmpty())
 				continue;
 
+			/* don't sync objects with an older version time than the endpoint's log position */
+			if (object->GetVersion() < endpoint->GetLocalLogPosition()) {
+				Log(LogDebug, "ApiListener")
+				    << "Skipping sync: object '" << object->GetName() << "'"
+				    << " is older than local log position of endpoint '"
+				    << endpoint->GetName() << "'.";
+				continue;
+			}
+
 			/* don't sync objects for non-matching parent-child zones */
 			if (!azone->IsChildOf(lzone) && azone != lzone) {
 				Log(LogDebug, "ApiListener")

lib/remote/configobjectutility.cpp

@@ -74,6 +74,9 @@ String ConfigObjectUtility::CreateObjectConfig(const Type::Ptr& type, const Stri
 
 	allAttrs->Remove("name");
 
+	/* update the version for config sync */
+	allAttrs->Set("version", Utility::GetTime());
+
 	std::ostringstream config;
 	ConfigWriter::EmitConfigItem(config, type->GetName(), name, false, templates, allAttrs);
 	ConfigWriter::EmitRaw(config, "\n");