How to track all items of a type

[captncraig]

I have a new custom entity that I would like to track all instances of. My mod needs to check all of them for various conditions on every few ticks, so I would like to be able to iterate over them quickly and easily.

I have a couple of options:

1. Keep a global collection of entities and update it on on_built_entity, on_robot_built_entity, all the mined events and so forth. Iterate over this every N ticks.
2. Run find_entities_filtered for the entire game board to find all entities of the given type.

I worry that 2 will take too long if run at high frequency in on_tick. Is that a bad practice? I worry with 1 that I will miss some events and end up with invalid items (which I can detect), or missing items (which I can't).

I don't feel like this is too unusual a scenario. I am looking at viewtopic.php?f=92&t=18102 and they use a version of approach #1, but it also bugs out with things like blueprint placed chests not getting registered properly.

How have other people approached this problem. Is there some sample code or a library for this? Thanks!

[prg]

The problem with the mod you linked is that it simply doesn't handle on_robot_built_entity at all. Just do this and you should be fine. You certainly want to avoid running find_entities_filtered over every single generated chunk repeatedly.

[captncraig]

Thanks, it seems to be working ok for me like that.