Fix race in multiple DB mirroring configurations.

controller/DB.hpp

@@ -114,6 +114,28 @@ public:
 	}
 
 protected:
+	inline bool _compareRecords(const nlohmann::json &a,const nlohmann::json &b)
+	{
+		if (a.is_object() == b.is_object()) {
+			if (a.is_object()) {
+				if (a.size() != b.size())
+					return false;
+				auto amap = a.get<nlohmann::json::object_t>();
+				auto bmap = b.get<nlohmann::json::object_t>();
+				for(auto ai=amap.begin();ai!=amap.end();++ai) {
+					if (ai->first != "revision") { // ignore revision, compare only non-revision-counter fields
+						auto bi = bmap.find(ai->first);
+						if ((bi == bmap.end())||(bi->second != ai->second))
+							return false;
+					}
+				}
+				return true;
+			}
+			return (a == b);
+		}
+		return false;
+	}
+
 	struct _Network
 	{
 		_Network() : mostRecentDeauthTime(0) {}

controller/DBMirrorSet.cpp

@@ -125,14 +125,14 @@ bool DBMirrorSet::save(nlohmann::json &record,bool notifyListeners)
 	}
 	if (notifyListeners) {
 		for(auto d=dbs.begin();d!=dbs.end();++d) {
-			if ((*d)->save(record,notifyListeners))
+			if ((*d)->save(record,true))
 				return true;
 		}
 		return false;
 	} else {
 		bool modified = false;
 		for(auto d=dbs.begin();d!=dbs.end();++d) {
-			modified |= (*d)->save(record,notifyListeners);
+			modified |= (*d)->save(record,false);
 		}
 		return modified;
 	}

controller/FileDB.cpp

@@ -98,7 +98,7 @@ bool FileDB::save(nlohmann::json &record,bool notifyListeners)
 			if (nwid) {
 				nlohmann::json old;
 				get(nwid,old);
-				if ((!old.is_object())||(old != record)) {
+				if ((!old.is_object())||(!_compareRecords(old,record))) {
 					record["revision"] = OSUtils::jsonInt(record["revision"],0ULL) + 1ULL;
 					OSUtils::ztsnprintf(p1,sizeof(p1),"%s" ZT_PATH_SEPARATOR_S "%.16llx.json",_networksPath.c_str(),nwid);
 					if (!OSUtils::writeFile(p1,OSUtils::jsonDump(record,-1)))
@@ -115,7 +115,7 @@ bool FileDB::save(nlohmann::json &record,bool notifyListeners)
 			if ((id)&&(nwid)) {
 				nlohmann::json network,old;
 				get(nwid,network,id,old);
-				if ((!old.is_object())||(old != record)) {
+				if ((!old.is_object())||(!_compareRecords(old,record))) {
 					record["revision"] = OSUtils::jsonInt(record["revision"],0ULL) + 1ULL;
 					OSUtils::ztsnprintf(pb,sizeof(pb),"%s" ZT_PATH_SEPARATOR_S "%.16llx" ZT_PATH_SEPARATOR_S "member",_networksPath.c_str(),(unsigned long long)nwid);
 					OSUtils::ztsnprintf(p1,sizeof(p1),"%s" ZT_PATH_SEPARATOR_S "%.10llx.json",pb,(unsigned long long)id);

controller/LFDB.cpp

@@ -369,7 +369,7 @@ bool LFDB::save(nlohmann::json &record,bool notifyListeners)
 		if (nwid) {
 			nlohmann::json old;
 			get(nwid,old);
-			if ((!old.is_object())||(old != record)) {
+			if ((!old.is_object())||(!_compareRecords(old,record))) {
 				record["revision"] = OSUtils::jsonInt(record["revision"],0ULL) + 1ULL;
 				_networkChanged(old,record,notifyListeners);
 				{
@@ -385,7 +385,7 @@ bool LFDB::save(nlohmann::json &record,bool notifyListeners)
 		if ((id)&&(nwid)) {
 			nlohmann::json network,old;
 			get(nwid,network,id,old);
-			if ((!old.is_object())||(old != record)) {
+			if ((!old.is_object())||(!_compareRecords(old,record))) {
 				record["revision"] = OSUtils::jsonInt(record["revision"],0ULL) + 1ULL;
 				_memberChanged(old,record,notifyListeners);
 				{

controller/PostgreSQL.cpp

@@ -183,7 +183,7 @@ bool PostgreSQL::save(nlohmann::json &record,bool notifyListeners)
 			if (nwid) {
 				nlohmann::json old;
 				get(nwid,old);
-				if ((!old.is_object())||(old != record)) {
+				if ((!old.is_object())||(!_compareRecords(old,record))) {
 					record["revision"] = OSUtils::jsonInt(record["revision"],0ULL) + 1ULL;
 					_commitQueue.post(std::pair<nlohmann::json,bool>(record,notifyListeners));
 					modified = true;
@@ -195,25 +195,13 @@ bool PostgreSQL::save(nlohmann::json &record,bool notifyListeners)
 			if ((id)&&(nwid)) {
 				nlohmann::json network,old;
 				get(nwid,network,id,old);
-				if ((!old.is_object())||(old != record)) {
+				if ((!old.is_object())||(!_compareRecords(old,record))) {
 					record["revision"] = OSUtils::jsonInt(record["revision"],0ULL) + 1ULL;
 					_commitQueue.post(std::pair<nlohmann::json,bool>(record,notifyListeners));
 					modified = true;
 				}
 			}
 		}
-		/*
-		waitForReady();
-		if (orig) {
-			if (*orig != record) {
-				record["revision"] = OSUtils::jsonInt(record["revision"],0ULL) + 1;
-				_commitQueue.post(new nlohmann::json(record));
-			}
-		} else {
-			record["revision"] = 1;
-			_commitQueue.post(new nlohmann::json(record));
-		}
-		*/
 	} catch (std::exception &e) {
 		fprintf(stderr, "Error on PostgreSQL::save: %s\n", e.what());
 	} catch (...) {