Bombsquad-Ballistica-Modded.../dist/ba_data/python/efro/call.py
2025-02-09 00:17:58 +05:30

97 lines
3.1 KiB
Python

# Released under the MIT License. See LICENSE for details.
#
"""Call related functionality shared between all efro components."""
from __future__ import annotations
import weakref
import threading
from typing import TYPE_CHECKING, TypeVar, Generic
T = TypeVar('T')
if TYPE_CHECKING:
from typing import Callable
class CallbackSet(Generic[T]):
"""A simple way to manage a set of callbacks.
Any number of calls can be registered with a callback set. Each
registration results in a Registration object that can be used to
deregister the call from the set later. Callbacks are also
implicitly deregistered when an entry is deallocated, so make sure
to hold on to the return value when adding.
CallbackSet instances should be used from a single thread only
(this will be checked in debug mode).
"""
def __init__(self) -> None:
self._entries: list[weakref.ref[CallbackRegistration[T]]] = []
self.thread: threading.Thread
if __debug__:
self.thread = threading.current_thread()
def register(self, call: T) -> CallbackRegistration[T]:
"""Register a new callback."""
assert threading.current_thread() == self.thread
self._prune()
entry = CallbackRegistration(call, self)
self._entries.append(weakref.ref(entry))
return entry
def getcalls(self) -> list[T]:
"""Return the current set of registered calls.
Note that this returns a flattened list of calls; generally this
should protect against calls which themselves add or remove
callbacks.
"""
assert threading.current_thread() == self.thread
self._prune()
# Ignore calls that have been deallocated or explicitly
# deregistered.
entries = [e() for e in self._entries]
return [e.call for e in entries if e is not None and e.call is not None]
def _prune(self) -> None:
# Quick-out if all our entries are intact.
needs_prune = False
for entry in self._entries:
entrytarget = entry()
if entrytarget is None or entrytarget.call is None:
needs_prune = True
break
if not needs_prune:
return
# Ok; something needs pruning. Rebuild the entries list.
newentries: list[weakref.ref[CallbackRegistration[T]]] = []
for entry in self._entries:
entrytarget = entry()
if entrytarget is not None and entrytarget.call is not None:
newentries.append(entry)
self._entries = newentries
class CallbackRegistration(Generic[T]):
"""An entry for a callback set."""
def __init__(self, call: T, callbackset: CallbackSet[T]) -> None:
self.call: T | None = call
self.callbackset: CallbackSet[T] | None = callbackset
def deregister(self) -> None:
"""Explicitly remove a callback from a CallbackSet."""
assert (
self.callbackset is None
or threading.current_thread() == self.callbackset.thread
)
# Simply clear the call to mark us as dead.
self.call = None