Drawing number of objects on sockets

[Durman]

Problem statement

The function is calling each time when UI is redrawing. UI is redrawing each time when mouse is passed over any interactive element on a screen. The function is calling other method of socket which is calling links method which is actually quite expensive. Calling links method takes O(n) time where n is number of links in a tree.

sverchok/core/socket_data.py

Lines 47 to 67 in 61deb2f

	def SvGetSocketInfo(socket):
	"""returns string to show in socket label"""
	global socket_data_cache
	ng = socket.id_data.name
	if socket.is_output:
	s_id = socket.socket_id
	elif socket.is_linked:
	other = socket.other
	if other:
	s_id = other.socket_id
	else:
	return ''
	else:
	return ''
	if ng in socket_data_cache:
	if s_id in socket_data_cache[ng]:
	data = socket_data_cache[ng][s_id]
	if data:
	return str(len(data))
	return ''

So with growing size of a tree number of calculations is growing exponentially and recalculating quite often. It definitely can be reimplemented. I think that number of objects can be recalculated during tree update event and memorize in sockets somewhere.

[zeffii]

perhaps, the socket class common can hold a 'object count', which is set only at the end of a successful completion of a node's process() (also means setting to a default 0 prior to calling process ).

i've thought about this too in the past when visiting these areas of code, and i'm supportive of reducing redundant cpu cycles, but here i'm apprehensive to implement object count.

[zeffii]

but whatever :) we can try it

[ly29]

Having a compiled links data structure would be good and would also make the update system easier.
Removing reroutes and wifi (if that is still is used) is a big win and would make the update system easier.

[ly29]

Made a very simple cache implementation for these kind of issues. Untested as a minimal implemenation.
https://github.com/nortikin/sverchok/blob/testNameCache/core/socket_data.py

[Durman]

By the way I was thinking about socket.sv_links approach and it looks it would be impossible to implement. Because what this method should returns? We can't keep straight references to nodes. Links to nodes can't be created via Pointer property. We can keep their names but search node by their name again returns to O(n**2) performance.

Or probably it would be possible to keep references to nodes but they will resetting upon each update event and undo event. In this case it becomes easier to crush Blender.

[nortikin]

default off
optionally turn it on from SvPanel and options also.
It was initially as replacement for text viewer before it appeared.

I will not miss personally.
Point before socket name when it joined - good approach

[Durman]

sverchok/core/sockets.py

Line 229 in 09e9788

info_text = t + '. ' + SvGetSocketInfo(self)

And performance without calling the function.

info_text = t + '. ' 

[nortikin]

every time calculate length is much of lost?

[Durman]

According the fact that not just number of objects of other output sockets should be shown but also the number of objects after they will be converted from that sockets the only way to improve performance is to calculate and to memorize this value during update event. Only case when number of objects does not coincide is conversion from vector to matrix sockets now. And the reason of it is that matrixes are treated differently and inconsistently with other data types.