id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc
15170	[Patch] SimplifyWayAction optimizations.	shinigami	shinigami	"I suppose it is not problem in common use case, but this action is used by OpenData plugin, where it is called for every loaded (sometimes very long) way. 

It seems that delNodes and newNodes (in simplifyWay) often contains same data. Problem is that in such case AbstractSet.removeAll is processed as repetitive scanning of given collection and it leads to o(n^2) complexity. 

Another big slowdown is counting of node frequency in method isRequiredNode, it iterates all way for every node. Simple precounted histogram of nodes makes it much faster.
"	enhancement	closed	normal		Core		wontfix	performance