Harvey
36 lines
1.2 KiB
Python
36 lines
1.2 KiB
Python
"""Singleton decorator and automatic cleanup registry for DI providers."""
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from __future__ import annotations
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from functools import lru_cache, wraps
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from typing import Callable, TypeVar
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F = TypeVar("F", bound=Callable)
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_singleton_registry: list[Callable] = []
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def singleton(fn: F) -> F:
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"""Wrap *fn* with ``@lru_cache(maxsize=1)`` and register it for automatic cleanup."""
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cached = lru_cache(maxsize=1)(fn)
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_singleton_registry.append(cached)
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@wraps(fn)
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def wrapper(*args, **kwargs):
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return cached(*args, **kwargs)
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# Expose cache_clear so callers can invalidate individual singletons
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wrapper.cache_clear = cached.cache_clear # type: ignore[attr-defined]
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wrapper.cache_info = cached.cache_info # type: ignore[attr-defined]
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wrapper._cached = cached # type: ignore[attr-defined]
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_singleton_registry[-1] = wrapper # replace with the wrapper so clear_all hits wrapper
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return wrapper # type: ignore[return-value]
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def clear_all_singletons() -> None:
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"""Call ``cache_clear()`` on every registered singleton provider."""
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for fn in _singleton_registry:
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cache_clear = getattr(fn, "cache_clear", None)
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if callable(cache_clear):
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cache_clear()
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