Registering more than 3070 operators caused overriden built-in operators to fail #105063

New Issue

Dion Moult · 2023-02-22T05:00:07+01:00

Dion Moult commented

2023-02-22 05:00:07 +01:00

If you register more than 3070 operators via bpy.utils.register_class, then an operator overriding a built-in operator stops working (i.e. doesn't run at all, no error message).

First, run this script to do a count of registered operators:

import bpy
import types

total = 0

def count_operators(obj):
    global total
    for name in dir(obj):
        subthing = getattr(obj, name)
        if isinstance(subthing, types.ModuleType):
            count_operators(subthing)
        else:
            total += 1
        
count_operators(bpy.ops)
print(total)

This gives me 2154 operators on my machine. This may be different on your machine depending if you have add-ons enabled.

I've determined the threshold where operators stop working at 3070.

See the attached buggysmall.py add-on with minimal code. The add-on simply contains one OverrideDelete operator, with the bl_idname = "object.delete" (i.e. the same operator that runs when you press "x" or delete an object). It also contains another Asdf1 operator that does absolutely nothing (i.e. just return {"FINISHED"} immediately).

If you install / enable the buggysmall.py the add-on, as expected when you delete an object, the override will be activated and instead of the object being deleted, you'll get a message printed in the console. This works completely as expected and demonstrates correct behaviour.

However, if you install / enable the buggy.py add-on, this is almost the same as buggysmall.py except it has 1000 operators that do absolutely nothing instead of 1. On my machine, 2154 + 1000 > 3070, so if you enable this and try to delete an object, the object will be deleted (i.e. the OverrideDelete operator will stop working).

I came across this when developing the BlenderBIM Add-on - it's a very, very large and complex add-on with about 900 operators so far and growing, so users have started reporting bugs if they have other add-ons installed that hit this limit.

If you register more than 3070 operators via bpy.utils.register_class, then an operator overriding a built-in operator stops working (i.e. doesn't run at all, no error message). First, run this script to do a count of registered operators: ```python import bpy import types total = 0 def count_operators(obj): global total for name in dir(obj): subthing = getattr(obj, name) if isinstance(subthing, types.ModuleType): count_operators(subthing) else: total += 1 count_operators(bpy.ops) print(total) ``` This gives me 2154 operators on my machine. This may be different on your machine depending if you have add-ons enabled. I've determined the threshold where operators stop working at 3070. See the attached `buggysmall.py` add-on with minimal code. The add-on simply contains one `OverrideDelete` operator, with the bl_idname = "object.delete" (i.e. the same operator that runs when you press "x" or delete an object). It also contains another `Asdf1` operator that does absolutely nothing (i.e. just return {"FINISHED"} immediately). If you install / enable the `buggysmall.py` the add-on, as expected when you delete an object, the override will be activated and instead of the object being deleted, you'll get a message printed in the console. This works completely as expected and demonstrates correct behaviour. However, if you install / enable the `buggy.py` add-on, this is almost the same as `buggysmall.py` except it has 1000 operators that do absolutely nothing instead of 1. On my machine, 2154 + 1000 > 3070, so if you enable this and try to delete an object, the object will be deleted (i.e. the `OverrideDelete` operator will stop working). I came across this when developing the BlenderBIM Add-on - it's a very, very large and complex add-on with about 900 operators so far and growing, so users have started reporting bugs if they have other add-ons installed that hit this limit.

buggysmall.py

1.0 KiB

buggy.py

151 KiB

Dion Moult added the

labels 2023-02-22 05:00:08 +01:00

Erik Abrahamsson commented

2023-02-22 10:01:01 +01:00

None of those overrides work for me, instead in a debug build I get an assert in

BLI_ghash_insert(global_ops_hash, (void *)ot->idname, ot);

at

BLI_assert((gh->flag & GHASH_FLAG_ALLOW_DUPES) || (BLI_ghash_haskey(gh, key) == 0));

which seems to suggest it's not meant to work to override in this way.

By adding this code above the ghash insert line above in wm_operatortype_append__end, it removes any old operator first and it works:

  if (BLI_ghash_haskey(global_ops_hash, (void *)ot->idname)) {
    WM_operatortype_remove_ptr(BLI_ghash_lookup(global_ops_hash, (void *)ot->idname));
  }

But I'm not sure if this is correct, someone with more experience will have to check this.

None of those overrides work for me, instead in a debug build I get an assert in `BLI_ghash_insert(global_ops_hash, (void *)ot->idname, ot);` at `BLI_assert((gh->flag & GHASH_FLAG_ALLOW_DUPES) || (BLI_ghash_haskey(gh, key) == 0));` which seems to suggest it's not meant to work to override in this way. By adding this code above the ghash insert line above in `wm_operatortype_append__end`, it removes any old operator first and it works: ``` if (BLI_ghash_haskey(global_ops_hash, (void *)ot->idname)) { WM_operatortype_remove_ptr(BLI_ghash_lookup(global_ops_hash, (void *)ot->idname)); } ``` But I'm not sure if this is correct, someone with more experience will have to check this.

Dion Moult commented

2023-02-22 10:43:21 +01:00

@erik85 that seems odd, because the override has an effect for me as well as other users who are using the add-on. Here's also a SO post describing how they use an override: https://blender.stackexchange.com/questions/184245/how-to-re-register-a-built-in-operator

So does Blender not allow us to override built-ins?

@erik85 that seems odd, because the override has an effect for me as well as other users who are using the add-on. Here's also a SO post describing how they use an override: https://blender.stackexchange.com/questions/184245/how-to-re-register-a-built-in-operator So does Blender not allow us to override built-ins?

Iliya Katushenock added

Module

Python API

Status

Needs Info from Developers

and removed

Status

Needs Triage

labels 2023-02-22 11:26:41 +01:00

Iliya Katushenock commented

2023-02-22 11:27:30 +01:00

Added a core as I'm not sure who is responsible for the built-in operators