Reduce overhead of LuaEntity::get_signals with parameter if_modified_since

[Harag]

I'd like to propose the following signature change to LuaEntity::get_signals():

Code: Select all

get_signals(wire_connector_id, extra_wire_connector_id?, if_modified_since?) → array[Signal]?, MapTick

Read all signals from the selected wire connector.

Parameters

wire_connector_id :: <as before>
extra_wire_connector_id :: <as before>
if_modified_since :: MapTick? only return fresh signals if they were modified after this tick

Return values
→ array[Signal]? Current values of all signals, nil if there are no signals or if there were no modifications
→ MapTick the tick the signals were last modified, less than or equal to if_modified_since if there were no modifications

With this mods like LTN and Cybersyn that frequently poll signals could greatly reduce Lua garbage overhead and subsequent recalculations for idle circuit networks.
I assume this information is already present somewhere because combinators know when to recalculate, too.

If this is added, there should probably also be a property LuaCircuitNetwork::last_modified : MapTick.

My guess is adding the same to LuaEntity::get_signal() would not be a big improvement. That function already returns an int, only.

[Stringweasel]

+1

Related: 98542

[The_LORD_thy_GOD]

Seconded. This could save considerably Lua time in any mod that uses combinators for gathering input.