Update 2025-04-13_16:25:39

venv/lib/python3.11/site-packages/sqlalchemy/util/preloaded.py

@@ -0,0 +1,150 @@
+# util/preloaded.py
+# Copyright (C) 2005-2025 the SQLAlchemy authors and contributors
+# <see AUTHORS file>
+#
+# This module is part of SQLAlchemy and is released under
+# the MIT License: https://www.opensource.org/licenses/mit-license.php
+# mypy: allow-untyped-defs, allow-untyped-calls
+
+"""supplies the "preloaded" registry to resolve circular module imports at
+runtime.
+
+"""
+from __future__ import annotations
+
+import sys
+from typing import Any
+from typing import Callable
+from typing import TYPE_CHECKING
+from typing import TypeVar
+
+_FN = TypeVar("_FN", bound=Callable[..., Any])
+
+
+if TYPE_CHECKING:
+    from sqlalchemy import dialects as _dialects
+    from sqlalchemy import orm as _orm
+    from sqlalchemy.engine import cursor as _engine_cursor
+    from sqlalchemy.engine import default as _engine_default
+    from sqlalchemy.engine import reflection as _engine_reflection
+    from sqlalchemy.engine import result as _engine_result
+    from sqlalchemy.engine import url as _engine_url
+    from sqlalchemy.orm import attributes as _orm_attributes
+    from sqlalchemy.orm import base as _orm_base
+    from sqlalchemy.orm import clsregistry as _orm_clsregistry
+    from sqlalchemy.orm import decl_api as _orm_decl_api
+    from sqlalchemy.orm import decl_base as _orm_decl_base
+    from sqlalchemy.orm import dependency as _orm_dependency
+    from sqlalchemy.orm import descriptor_props as _orm_descriptor_props
+    from sqlalchemy.orm import mapperlib as _orm_mapper
+    from sqlalchemy.orm import properties as _orm_properties
+    from sqlalchemy.orm import relationships as _orm_relationships
+    from sqlalchemy.orm import session as _orm_session
+    from sqlalchemy.orm import state as _orm_state
+    from sqlalchemy.orm import strategies as _orm_strategies
+    from sqlalchemy.orm import strategy_options as _orm_strategy_options
+    from sqlalchemy.orm import util as _orm_util
+    from sqlalchemy.sql import default_comparator as _sql_default_comparator
+    from sqlalchemy.sql import dml as _sql_dml
+    from sqlalchemy.sql import elements as _sql_elements
+    from sqlalchemy.sql import functions as _sql_functions
+    from sqlalchemy.sql import naming as _sql_naming
+    from sqlalchemy.sql import schema as _sql_schema
+    from sqlalchemy.sql import selectable as _sql_selectable
+    from sqlalchemy.sql import sqltypes as _sql_sqltypes
+    from sqlalchemy.sql import traversals as _sql_traversals
+    from sqlalchemy.sql import util as _sql_util
+
+    # sigh, appease mypy 0.971 which does not accept imports as instance
+    # variables of a module
+    dialects = _dialects
+    engine_cursor = _engine_cursor
+    engine_default = _engine_default
+    engine_reflection = _engine_reflection
+    engine_result = _engine_result
+    engine_url = _engine_url
+    orm_clsregistry = _orm_clsregistry
+    orm_base = _orm_base
+    orm = _orm
+    orm_attributes = _orm_attributes
+    orm_decl_api = _orm_decl_api
+    orm_decl_base = _orm_decl_base
+    orm_descriptor_props = _orm_descriptor_props
+    orm_dependency = _orm_dependency
+    orm_mapper = _orm_mapper
+    orm_properties = _orm_properties
+    orm_relationships = _orm_relationships
+    orm_session = _orm_session
+    orm_strategies = _orm_strategies
+    orm_strategy_options = _orm_strategy_options
+    orm_state = _orm_state
+    orm_util = _orm_util
+    sql_default_comparator = _sql_default_comparator
+    sql_dml = _sql_dml
+    sql_elements = _sql_elements
+    sql_functions = _sql_functions
+    sql_naming = _sql_naming
+    sql_selectable = _sql_selectable
+    sql_traversals = _sql_traversals
+    sql_schema = _sql_schema
+    sql_sqltypes = _sql_sqltypes
+    sql_util = _sql_util
+
+
+class _ModuleRegistry:
+    """Registry of modules to load in a package init file.
+
+    To avoid potential thread safety issues for imports that are deferred
+    in a function, like https://bugs.python.org/issue38884, these modules
+    are added to the system module cache by importing them after the packages
+    has finished initialization.
+
+    A global instance is provided under the name :attr:`.preloaded`. Use
+    the function :func:`.preload_module` to register modules to load and
+    :meth:`.import_prefix` to load all the modules that start with the
+    given path.
+
+    While the modules are loaded in the global module cache, it's advisable
+    to access them using :attr:`.preloaded` to ensure that it was actually
+    registered. Each registered module is added to the instance ``__dict__``
+    in the form `<package>_<module>`, omitting ``sqlalchemy`` from the package
+    name. Example: ``sqlalchemy.sql.util`` becomes ``preloaded.sql_util``.
+    """
+
+    def __init__(self, prefix="sqlalchemy."):
+        self.module_registry = set()
+        self.prefix = prefix
+
+    def preload_module(self, *deps: str) -> Callable[[_FN], _FN]:
+        """Adds the specified modules to the list to load.
+
+        This method can be used both as a normal function and as a decorator.
+        No change is performed to the decorated object.
+        """
+        self.module_registry.update(deps)
+        return lambda fn: fn
+
+    def import_prefix(self, path: str) -> None:
+        """Resolve all the modules in the registry that start with the
+        specified path.
+        """
+        for module in self.module_registry:
+            if self.prefix:
+                key = module.split(self.prefix)[-1].replace(".", "_")
+            else:
+                key = module
+            if (
+                not path or module.startswith(path)
+            ) and key not in self.__dict__:
+                __import__(module, globals(), locals())
+                self.__dict__[key] = globals()[key] = sys.modules[module]
+
+
+_reg = _ModuleRegistry()
+preload_module = _reg.preload_module
+import_prefix = _reg.import_prefix
+
+# this appears to do absolutely nothing for any version of mypy
+# if TYPE_CHECKING:
+#    def __getattr__(key: str) -> ModuleType:
+#        ...