replace txQueue list by vector for faster memory access and less allocations

node/Multicaster.cpp

@@ -320,10 +320,12 @@ void Multicaster::clean(uint64_t now)
 {
 	Mutex::Lock _l(_groups_m);
 	for(std::map< std::pair<uint64_t,MulticastGroup>,MulticastGroupStatus >::iterator mm(_groups.begin());mm!=_groups.end();) {
-		for(std::list<OutboundMulticast>::iterator tx(mm->second.txQueue.begin());tx!=mm->second.txQueue.end();) {
-			if ((tx->expired(now))||(tx->atLimit()))
-				mm->second.txQueue.erase(tx++);
-			else ++tx;
+		for(std::vector<OutboundMulticast>::iterator tx(mm->second.txQueue.begin());tx!=mm->second.txQueue.end();) {
+			if ((tx->expired(now))||(tx->atLimit())) {
+				// erase element (replace by last)
+				*tx = mm->second.txQueue.back();
+				mm->second.txQueue.pop_back();
+			} else ++tx;
 		}
 
 		unsigned long count = 0;
@@ -371,14 +373,16 @@ void Multicaster::_add(uint64_t now,uint64_t nwid,const MulticastGroup &mg,Multi
 
 	//TRACE("..MC %s joined multicast group %.16llx/%s via %s",member.toString().c_str(),nwid,mg.toString().c_str(),((learnedFrom) ? learnedFrom.toString().c_str() : "(direct)"));
 
-	for(std::list<OutboundMulticast>::iterator tx(gs.txQueue.begin());tx!=gs.txQueue.end();) {
+	for(std::vector<OutboundMulticast>::iterator tx(gs.txQueue.begin());tx!=gs.txQueue.end();) {
 		if (tx->atLimit()) {
 			gs.txQueue.erase(tx++);
 		} else {
 			tx->sendIfNew(RR,member);
-			if (tx->atLimit())
-				gs.txQueue.erase(tx++);
-			else ++tx;
+			if (tx->atLimit()) {
+				// erase element (replace by last)
+				*tx = gs.txQueue.back();
+				gs.txQueue.pop_back();
+			} else ++tx;
 		}
 	}
 }

node/Multicaster.hpp

@@ -70,7 +70,7 @@ private:
 		MulticastGroupStatus() : lastExplicitGather(0) {}
 
 		uint64_t lastExplicitGather;
-		std::list<OutboundMulticast> txQueue; // pending outbound multicasts
+		std::vector<OutboundMulticast> txQueue; // pending outbound multicasts
 		std::vector<MulticastGroupMember> members; // members of this group
 	};