Source code for geoh5py.shared.weakref_utils

#  Copyright (c) 2023 Mira Geoscience Ltd.
#  This file is part of geoh5py.
#  geoh5py is free software: you can redistribute it and/or modify
#  it under the terms of the GNU Lesser General Public License as published by
#  the Free Software Foundation, either version 3 of the License, or
#  (at your option) any later version.
#  geoh5py is distributed in the hope that it will be useful,
#  but WITHOUT ANY WARRANTY; without even the implied warranty of
#  GNU Lesser General Public License for more details.
#  You should have received a copy of the GNU Lesser General Public License
#  along with geoh5py.  If not, see <>.

from __future__ import annotations

import weakref
from typing import TypeVar
from weakref import ReferenceType

K = TypeVar("K")  # pylint: disable=invalid-name
T = TypeVar("T")  # pylint: disable=invalid-name

[docs]def remove_none_referents(some_dict: dict[K, ReferenceType]): """ Removes any key from the given ``some_dict`` where the value is a reference to a deleted value (that is where referent of the ``weakref`` value is None). :param some_dict: The dictionary to be cleaned up. """ dead_keys = [key for key, value in some_dict.items() if value() is None] for key in dead_keys: del some_dict[key]
[docs]def get_clean_ref(some_dict: dict[K, ReferenceType[T]], key: K) -> T | None: """ Gets the referent value for the given ``key`` in a ``some_dict`` of ``weakref`` values. In case ``key`` points to a reference to a deleted value, remove that key from ``some_dict`` on the fly, and returns None. :param some_dict: The dictionary of ``weakref`` values. :param key: The key :return: the referent value for ``key`` if found in the the dictionary, else None. """ ref = some_dict.get(key, None) if ref is None: return None if ref() is None: del some_dict[key] return None return ref()
[docs]def insert_once(some_dict: dict[K, ReferenceType], key: K, value): """ Check if the reference to an Entity with uuid is already in use. :param some_dict: Dictionary of UUID keys and weakref values. :param key: UUID key to be checked. :param value: Entity to be checked :return: Dictionary with clean weakref """ existing_ref = some_dict.get(key, None) if existing_ref is not None and existing_ref() is not None: raise RuntimeError(f"Key '{key}' already used.") some_dict[key] = weakref.ref(value)