Current File : /opt/hc_python/lib/python3.12/site-packages/sqlalchemy/sql//_py_util.py
# sql/_py_util.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
from __future__ import annotations
import typing
from typing import Any
from typing import Dict
from typing import Tuple
from typing import Union
from ..util.typing import Literal
if typing.TYPE_CHECKING:
from .cache_key import CacheConst
class prefix_anon_map(Dict[str, str]):
"""A map that creates new keys for missing key access.
Considers keys of the form "<ident> <name>" to produce
new symbols "<name>_<index>", where "index" is an incrementing integer
corresponding to <name>.
Inlines the approach taken by :class:`sqlalchemy.util.PopulateDict` which
is otherwise usually used for this type of operation.
"""
def __missing__(self, key: str) -> str:
(ident, derived) = key.split(" ", 1)
anonymous_counter = self.get(derived, 1)
self[derived] = anonymous_counter + 1 # type: ignore
value = f"{derived}_{anonymous_counter}"
self[key] = value
return value
class cache_anon_map(
Dict[Union[int, "Literal[CacheConst.NO_CACHE]"], Union[Literal[True], str]]
):
"""A map that creates new keys for missing key access.
Produces an incrementing sequence given a series of unique keys.
This is similar to the compiler prefix_anon_map class although simpler.
Inlines the approach taken by :class:`sqlalchemy.util.PopulateDict` which
is otherwise usually used for this type of operation.
"""
_index = 0
def get_anon(self, object_: Any) -> Tuple[str, bool]:
idself = id(object_)
if idself in self:
s_val = self[idself]
assert s_val is not True
return s_val, True
else:
# inline of __missing__
self[idself] = id_ = str(self._index)
self._index += 1
return id_, False
def __missing__(self, key: int) -> str:
self[key] = val = str(self._index)
self._index += 1
return val
