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809 lines
25 KiB
809 lines
25 KiB
# orm/path_registry.py
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# Copyright (C) 2005-2024 the SQLAlchemy authors and contributors
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# <see AUTHORS file>
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#
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# This module is part of SQLAlchemy and is released under
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# the MIT License: https://www.opensource.org/licenses/mit-license.php
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"""Path tracking utilities, representing mapper graph traversals.
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"""
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from __future__ import annotations
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from functools import reduce
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from itertools import chain
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import logging
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import operator
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from typing import Any
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from typing import cast
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from typing import Dict
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from typing import Iterator
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from typing import List
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from typing import Optional
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from typing import overload
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from typing import Sequence
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from typing import Tuple
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from typing import TYPE_CHECKING
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from typing import Union
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from . import base as orm_base
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from ._typing import insp_is_mapper_property
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from .. import exc
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from .. import util
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from ..sql import visitors
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from ..sql.cache_key import HasCacheKey
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if TYPE_CHECKING:
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from ._typing import _InternalEntityType
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from .interfaces import MapperProperty
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from .mapper import Mapper
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from .relationships import RelationshipProperty
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from .util import AliasedInsp
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from ..sql.cache_key import _CacheKeyTraversalType
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from ..sql.elements import BindParameter
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from ..sql.visitors import anon_map
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from ..util.typing import _LiteralStar
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from ..util.typing import TypeGuard
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def is_root(path: PathRegistry) -> TypeGuard[RootRegistry]: ...
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def is_entity(path: PathRegistry) -> TypeGuard[AbstractEntityRegistry]: ...
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else:
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is_root = operator.attrgetter("is_root")
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is_entity = operator.attrgetter("is_entity")
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_SerializedPath = List[Any]
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_StrPathToken = str
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_PathElementType = Union[
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_StrPathToken, "_InternalEntityType[Any]", "MapperProperty[Any]"
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]
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# the representation is in fact
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# a tuple with alternating:
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# [_InternalEntityType[Any], Union[str, MapperProperty[Any]],
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# _InternalEntityType[Any], Union[str, MapperProperty[Any]], ...]
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# this might someday be a tuple of 2-tuples instead, but paths can be
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# chopped at odd intervals as well so this is less flexible
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_PathRepresentation = Tuple[_PathElementType, ...]
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# NOTE: these names are weird since the array is 0-indexed,
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# the "_Odd" entries are at 0, 2, 4, etc
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_OddPathRepresentation = Sequence["_InternalEntityType[Any]"]
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_EvenPathRepresentation = Sequence[Union["MapperProperty[Any]", str]]
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log = logging.getLogger(__name__)
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def _unreduce_path(path: _SerializedPath) -> PathRegistry:
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return PathRegistry.deserialize(path)
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_WILDCARD_TOKEN: _LiteralStar = "*"
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_DEFAULT_TOKEN = "_sa_default"
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class PathRegistry(HasCacheKey):
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"""Represent query load paths and registry functions.
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Basically represents structures like:
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(<User mapper>, "orders", <Order mapper>, "items", <Item mapper>)
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These structures are generated by things like
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query options (joinedload(), subqueryload(), etc.) and are
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used to compose keys stored in the query._attributes dictionary
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for various options.
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They are then re-composed at query compile/result row time as
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the query is formed and as rows are fetched, where they again
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serve to compose keys to look up options in the context.attributes
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dictionary, which is copied from query._attributes.
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The path structure has a limited amount of caching, where each
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"root" ultimately pulls from a fixed registry associated with
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the first mapper, that also contains elements for each of its
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property keys. However paths longer than two elements, which
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are the exception rather than the rule, are generated on an
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as-needed basis.
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"""
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__slots__ = ()
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is_token = False
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is_root = False
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has_entity = False
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is_property = False
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is_entity = False
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is_unnatural: bool
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path: _PathRepresentation
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natural_path: _PathRepresentation
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parent: Optional[PathRegistry]
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root: RootRegistry
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_cache_key_traversal: _CacheKeyTraversalType = [
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("path", visitors.ExtendedInternalTraversal.dp_has_cache_key_list)
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]
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def __eq__(self, other: Any) -> bool:
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try:
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return other is not None and self.path == other._path_for_compare
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except AttributeError:
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util.warn(
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"Comparison of PathRegistry to %r is not supported"
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% (type(other))
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)
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return False
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def __ne__(self, other: Any) -> bool:
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try:
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return other is None or self.path != other._path_for_compare
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except AttributeError:
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util.warn(
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"Comparison of PathRegistry to %r is not supported"
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% (type(other))
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)
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return True
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@property
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def _path_for_compare(self) -> Optional[_PathRepresentation]:
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return self.path
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def odd_element(self, index: int) -> _InternalEntityType[Any]:
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return self.path[index] # type: ignore
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def set(self, attributes: Dict[Any, Any], key: Any, value: Any) -> None:
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log.debug("set '%s' on path '%s' to '%s'", key, self, value)
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attributes[(key, self.natural_path)] = value
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def setdefault(
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self, attributes: Dict[Any, Any], key: Any, value: Any
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) -> None:
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log.debug("setdefault '%s' on path '%s' to '%s'", key, self, value)
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attributes.setdefault((key, self.natural_path), value)
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def get(
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self, attributes: Dict[Any, Any], key: Any, value: Optional[Any] = None
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) -> Any:
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key = (key, self.natural_path)
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if key in attributes:
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return attributes[key]
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else:
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return value
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def __len__(self) -> int:
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return len(self.path)
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def __hash__(self) -> int:
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return id(self)
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@overload
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def __getitem__(self, entity: _StrPathToken) -> TokenRegistry: ...
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@overload
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def __getitem__(self, entity: int) -> _PathElementType: ...
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@overload
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def __getitem__(self, entity: slice) -> _PathRepresentation: ...
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@overload
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def __getitem__(
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self, entity: _InternalEntityType[Any]
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) -> AbstractEntityRegistry: ...
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@overload
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def __getitem__(self, entity: MapperProperty[Any]) -> PropRegistry: ...
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def __getitem__(
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self,
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entity: Union[
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_StrPathToken,
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int,
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slice,
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_InternalEntityType[Any],
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MapperProperty[Any],
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],
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) -> Union[
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TokenRegistry,
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_PathElementType,
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_PathRepresentation,
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PropRegistry,
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AbstractEntityRegistry,
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]:
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raise NotImplementedError()
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# TODO: what are we using this for?
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@property
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def length(self) -> int:
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return len(self.path)
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def pairs(
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self,
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) -> Iterator[
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Tuple[_InternalEntityType[Any], Union[str, MapperProperty[Any]]]
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]:
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odd_path = cast(_OddPathRepresentation, self.path)
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even_path = cast(_EvenPathRepresentation, odd_path)
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for i in range(0, len(odd_path), 2):
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yield odd_path[i], even_path[i + 1]
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def contains_mapper(self, mapper: Mapper[Any]) -> bool:
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_m_path = cast(_OddPathRepresentation, self.path)
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for path_mapper in [_m_path[i] for i in range(0, len(_m_path), 2)]:
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if path_mapper.mapper.isa(mapper):
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return True
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else:
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return False
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def contains(self, attributes: Dict[Any, Any], key: Any) -> bool:
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return (key, self.path) in attributes
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def __reduce__(self) -> Any:
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return _unreduce_path, (self.serialize(),)
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@classmethod
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def _serialize_path(cls, path: _PathRepresentation) -> _SerializedPath:
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_m_path = cast(_OddPathRepresentation, path)
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_p_path = cast(_EvenPathRepresentation, path)
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return list(
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zip(
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tuple(
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m.class_ if (m.is_mapper or m.is_aliased_class) else str(m)
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for m in [_m_path[i] for i in range(0, len(_m_path), 2)]
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),
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tuple(
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p.key if insp_is_mapper_property(p) else str(p)
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for p in [_p_path[i] for i in range(1, len(_p_path), 2)]
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)
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+ (None,),
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)
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)
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@classmethod
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def _deserialize_path(cls, path: _SerializedPath) -> _PathRepresentation:
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def _deserialize_mapper_token(mcls: Any) -> Any:
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return (
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# note: we likely dont want configure=True here however
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# this is maintained at the moment for backwards compatibility
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orm_base._inspect_mapped_class(mcls, configure=True)
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if mcls not in PathToken._intern
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else PathToken._intern[mcls]
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)
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def _deserialize_key_token(mcls: Any, key: Any) -> Any:
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if key is None:
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return None
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elif key in PathToken._intern:
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return PathToken._intern[key]
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else:
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mp = orm_base._inspect_mapped_class(mcls, configure=True)
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assert mp is not None
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return mp.attrs[key]
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p = tuple(
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chain(
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*[
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(
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_deserialize_mapper_token(mcls),
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_deserialize_key_token(mcls, key),
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)
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for mcls, key in path
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]
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)
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)
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if p and p[-1] is None:
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p = p[0:-1]
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return p
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def serialize(self) -> _SerializedPath:
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path = self.path
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return self._serialize_path(path)
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@classmethod
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def deserialize(cls, path: _SerializedPath) -> PathRegistry:
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assert path is not None
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p = cls._deserialize_path(path)
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return cls.coerce(p)
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@overload
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@classmethod
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def per_mapper(cls, mapper: Mapper[Any]) -> CachingEntityRegistry: ...
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@overload
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@classmethod
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def per_mapper(cls, mapper: AliasedInsp[Any]) -> SlotsEntityRegistry: ...
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@classmethod
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def per_mapper(
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cls, mapper: _InternalEntityType[Any]
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) -> AbstractEntityRegistry:
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if mapper.is_mapper:
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return CachingEntityRegistry(cls.root, mapper)
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else:
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return SlotsEntityRegistry(cls.root, mapper)
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@classmethod
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def coerce(cls, raw: _PathRepresentation) -> PathRegistry:
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def _red(prev: PathRegistry, next_: _PathElementType) -> PathRegistry:
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return prev[next_]
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# can't quite get mypy to appreciate this one :)
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return reduce(_red, raw, cls.root) # type: ignore
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def __add__(self, other: PathRegistry) -> PathRegistry:
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def _red(prev: PathRegistry, next_: _PathElementType) -> PathRegistry:
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return prev[next_]
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return reduce(_red, other.path, self)
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def __str__(self) -> str:
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return f"ORM Path[{' -> '.join(str(elem) for elem in self.path)}]"
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def __repr__(self) -> str:
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return f"{self.__class__.__name__}({self.path!r})"
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class CreatesToken(PathRegistry):
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__slots__ = ()
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is_aliased_class: bool
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is_root: bool
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def token(self, token: _StrPathToken) -> TokenRegistry:
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if token.endswith(f":{_WILDCARD_TOKEN}"):
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return TokenRegistry(self, token)
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elif token.endswith(f":{_DEFAULT_TOKEN}"):
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return TokenRegistry(self.root, token)
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else:
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raise exc.ArgumentError(f"invalid token: {token}")
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class RootRegistry(CreatesToken):
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"""Root registry, defers to mappers so that
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paths are maintained per-root-mapper.
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"""
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__slots__ = ()
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inherit_cache = True
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path = natural_path = ()
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has_entity = False
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is_aliased_class = False
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is_root = True
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is_unnatural = False
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def _getitem(
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self, entity: Any
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) -> Union[TokenRegistry, AbstractEntityRegistry]:
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if entity in PathToken._intern:
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if TYPE_CHECKING:
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assert isinstance(entity, _StrPathToken)
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return TokenRegistry(self, PathToken._intern[entity])
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else:
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try:
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return entity._path_registry # type: ignore
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except AttributeError:
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raise IndexError(
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f"invalid argument for RootRegistry.__getitem__: {entity}"
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)
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def _truncate_recursive(self) -> RootRegistry:
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return self
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if not TYPE_CHECKING:
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__getitem__ = _getitem
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PathRegistry.root = RootRegistry()
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class PathToken(orm_base.InspectionAttr, HasCacheKey, str):
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"""cacheable string token"""
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_intern: Dict[str, PathToken] = {}
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def _gen_cache_key(
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self, anon_map: anon_map, bindparams: List[BindParameter[Any]]
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) -> Tuple[Any, ...]:
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return (str(self),)
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@property
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def _path_for_compare(self) -> Optional[_PathRepresentation]:
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return None
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@classmethod
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def intern(cls, strvalue: str) -> PathToken:
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if strvalue in cls._intern:
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return cls._intern[strvalue]
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else:
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cls._intern[strvalue] = result = PathToken(strvalue)
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return result
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class TokenRegistry(PathRegistry):
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__slots__ = ("token", "parent", "path", "natural_path")
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inherit_cache = True
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token: _StrPathToken
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parent: CreatesToken
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def __init__(self, parent: CreatesToken, token: _StrPathToken):
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token = PathToken.intern(token)
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self.token = token
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self.parent = parent
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self.path = parent.path + (token,)
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self.natural_path = parent.natural_path + (token,)
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has_entity = False
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is_token = True
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def generate_for_superclasses(self) -> Iterator[PathRegistry]:
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# NOTE: this method is no longer used. consider removal
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parent = self.parent
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if is_root(parent):
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yield self
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return
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if TYPE_CHECKING:
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assert isinstance(parent, AbstractEntityRegistry)
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if not parent.is_aliased_class:
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for mp_ent in parent.mapper.iterate_to_root():
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yield TokenRegistry(parent.parent[mp_ent], self.token)
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elif (
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parent.is_aliased_class
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and cast(
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"AliasedInsp[Any]",
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parent.entity,
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)._is_with_polymorphic
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):
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yield self
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for ent in cast(
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"AliasedInsp[Any]", parent.entity
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)._with_polymorphic_entities:
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yield TokenRegistry(parent.parent[ent], self.token)
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else:
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yield self
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def _generate_natural_for_superclasses(
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self,
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) -> Iterator[_PathRepresentation]:
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parent = self.parent
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if is_root(parent):
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yield self.natural_path
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return
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if TYPE_CHECKING:
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assert isinstance(parent, AbstractEntityRegistry)
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for mp_ent in parent.mapper.iterate_to_root():
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yield TokenRegistry(parent.parent[mp_ent], self.token).natural_path
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if (
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parent.is_aliased_class
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and cast(
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"AliasedInsp[Any]",
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parent.entity,
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)._is_with_polymorphic
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):
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yield self.natural_path
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for ent in cast(
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"AliasedInsp[Any]", parent.entity
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)._with_polymorphic_entities:
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yield (
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TokenRegistry(parent.parent[ent], self.token).natural_path
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)
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else:
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yield self.natural_path
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def _getitem(self, entity: Any) -> Any:
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try:
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return self.path[entity]
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except TypeError as err:
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raise IndexError(f"{entity}") from err
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if not TYPE_CHECKING:
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__getitem__ = _getitem
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class PropRegistry(PathRegistry):
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__slots__ = (
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"prop",
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"parent",
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"path",
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"natural_path",
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"has_entity",
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"entity",
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"mapper",
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"_wildcard_path_loader_key",
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"_default_path_loader_key",
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"_loader_key",
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"is_unnatural",
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)
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inherit_cache = True
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is_property = True
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prop: MapperProperty[Any]
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mapper: Optional[Mapper[Any]]
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entity: Optional[_InternalEntityType[Any]]
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def __init__(
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self, parent: AbstractEntityRegistry, prop: MapperProperty[Any]
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):
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# restate this path in terms of the
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# given MapperProperty's parent.
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insp = cast("_InternalEntityType[Any]", parent[-1])
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natural_parent: AbstractEntityRegistry = parent
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# inherit "is_unnatural" from the parent
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self.is_unnatural = parent.parent.is_unnatural or bool(
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parent.mapper.inherits
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)
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if not insp.is_aliased_class or insp._use_mapper_path: # type: ignore
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parent = natural_parent = parent.parent[prop.parent]
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elif (
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insp.is_aliased_class
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and insp.with_polymorphic_mappers
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and prop.parent in insp.with_polymorphic_mappers
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):
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subclass_entity: _InternalEntityType[Any] = parent[-1]._entity_for_mapper(prop.parent) # type: ignore # noqa: E501
|
|
parent = parent.parent[subclass_entity]
|
|
|
|
# when building a path where with_polymorphic() is in use,
|
|
# special logic to determine the "natural path" when subclass
|
|
# entities are used.
|
|
#
|
|
# here we are trying to distinguish between a path that starts
|
|
# on a the with_polymorhpic entity vs. one that starts on a
|
|
# normal entity that introduces a with_polymorphic() in the
|
|
# middle using of_type():
|
|
#
|
|
# # as in test_polymorphic_rel->
|
|
# # test_subqueryload_on_subclass_uses_path_correctly
|
|
# wp = with_polymorphic(RegularEntity, "*")
|
|
# sess.query(wp).options(someload(wp.SomeSubEntity.foos))
|
|
#
|
|
# vs
|
|
#
|
|
# # as in test_relationship->JoinedloadWPolyOfTypeContinued
|
|
# wp = with_polymorphic(SomeFoo, "*")
|
|
# sess.query(RegularEntity).options(
|
|
# someload(RegularEntity.foos.of_type(wp))
|
|
# .someload(wp.SubFoo.bar)
|
|
# )
|
|
#
|
|
# in the former case, the Query as it generates a path that we
|
|
# want to match will be in terms of the with_polymorphic at the
|
|
# beginning. in the latter case, Query will generate simple
|
|
# paths that don't know about this with_polymorphic, so we must
|
|
# use a separate natural path.
|
|
#
|
|
#
|
|
if parent.parent:
|
|
natural_parent = parent.parent[subclass_entity.mapper]
|
|
self.is_unnatural = True
|
|
else:
|
|
natural_parent = parent
|
|
elif (
|
|
natural_parent.parent
|
|
and insp.is_aliased_class
|
|
and prop.parent # this should always be the case here
|
|
is not insp.mapper
|
|
and insp.mapper.isa(prop.parent)
|
|
):
|
|
natural_parent = parent.parent[prop.parent]
|
|
|
|
self.prop = prop
|
|
self.parent = parent
|
|
self.path = parent.path + (prop,)
|
|
self.natural_path = natural_parent.natural_path + (prop,)
|
|
|
|
self.has_entity = prop._links_to_entity
|
|
if prop._is_relationship:
|
|
if TYPE_CHECKING:
|
|
assert isinstance(prop, RelationshipProperty)
|
|
self.entity = prop.entity
|
|
self.mapper = prop.mapper
|
|
else:
|
|
self.entity = None
|
|
self.mapper = None
|
|
|
|
self._wildcard_path_loader_key = (
|
|
"loader",
|
|
parent.natural_path + self.prop._wildcard_token,
|
|
)
|
|
self._default_path_loader_key = self.prop._default_path_loader_key
|
|
self._loader_key = ("loader", self.natural_path)
|
|
|
|
def _truncate_recursive(self) -> PropRegistry:
|
|
earliest = None
|
|
for i, token in enumerate(reversed(self.path[:-1])):
|
|
if token is self.prop:
|
|
earliest = i
|
|
|
|
if earliest is None:
|
|
return self
|
|
else:
|
|
return self.coerce(self.path[0 : -(earliest + 1)]) # type: ignore
|
|
|
|
@property
|
|
def entity_path(self) -> AbstractEntityRegistry:
|
|
assert self.entity is not None
|
|
return self[self.entity]
|
|
|
|
def _getitem(
|
|
self, entity: Union[int, slice, _InternalEntityType[Any]]
|
|
) -> Union[AbstractEntityRegistry, _PathElementType, _PathRepresentation]:
|
|
if isinstance(entity, (int, slice)):
|
|
return self.path[entity]
|
|
else:
|
|
return SlotsEntityRegistry(self, entity)
|
|
|
|
if not TYPE_CHECKING:
|
|
__getitem__ = _getitem
|
|
|
|
|
|
class AbstractEntityRegistry(CreatesToken):
|
|
__slots__ = (
|
|
"key",
|
|
"parent",
|
|
"is_aliased_class",
|
|
"path",
|
|
"entity",
|
|
"natural_path",
|
|
)
|
|
|
|
has_entity = True
|
|
is_entity = True
|
|
|
|
parent: Union[RootRegistry, PropRegistry]
|
|
key: _InternalEntityType[Any]
|
|
entity: _InternalEntityType[Any]
|
|
is_aliased_class: bool
|
|
|
|
def __init__(
|
|
self,
|
|
parent: Union[RootRegistry, PropRegistry],
|
|
entity: _InternalEntityType[Any],
|
|
):
|
|
self.key = entity
|
|
self.parent = parent
|
|
self.is_aliased_class = entity.is_aliased_class
|
|
self.entity = entity
|
|
self.path = parent.path + (entity,)
|
|
|
|
# the "natural path" is the path that we get when Query is traversing
|
|
# from the lead entities into the various relationships; it corresponds
|
|
# to the structure of mappers and relationships. when we are given a
|
|
# path that comes from loader options, as of 1.3 it can have ac-hoc
|
|
# with_polymorphic() and other AliasedInsp objects inside of it, which
|
|
# are usually not present in mappings. So here we track both the
|
|
# "enhanced" path in self.path and the "natural" path that doesn't
|
|
# include those objects so these two traversals can be matched up.
|
|
|
|
# the test here for "(self.is_aliased_class or parent.is_unnatural)"
|
|
# are to avoid the more expensive conditional logic that follows if we
|
|
# know we don't have to do it. This conditional can just as well be
|
|
# "if parent.path:", it just is more function calls.
|
|
#
|
|
# This is basically the only place that the "is_unnatural" flag
|
|
# actually changes behavior.
|
|
if parent.path and (self.is_aliased_class or parent.is_unnatural):
|
|
# this is an infrequent code path used only for loader strategies
|
|
# that also make use of of_type().
|
|
if entity.mapper.isa(parent.natural_path[-1].mapper): # type: ignore # noqa: E501
|
|
self.natural_path = parent.natural_path + (entity.mapper,)
|
|
else:
|
|
self.natural_path = parent.natural_path + (
|
|
parent.natural_path[-1].entity, # type: ignore
|
|
)
|
|
# it seems to make sense that since these paths get mixed up
|
|
# with statements that are cached or not, we should make
|
|
# sure the natural path is cacheable across different occurrences
|
|
# of equivalent AliasedClass objects. however, so far this
|
|
# does not seem to be needed for whatever reason.
|
|
# elif not parent.path and self.is_aliased_class:
|
|
# self.natural_path = (self.entity._generate_cache_key()[0], )
|
|
else:
|
|
self.natural_path = self.path
|
|
|
|
def _truncate_recursive(self) -> AbstractEntityRegistry:
|
|
return self.parent._truncate_recursive()[self.entity]
|
|
|
|
@property
|
|
def root_entity(self) -> _InternalEntityType[Any]:
|
|
return self.odd_element(0)
|
|
|
|
@property
|
|
def entity_path(self) -> PathRegistry:
|
|
return self
|
|
|
|
@property
|
|
def mapper(self) -> Mapper[Any]:
|
|
return self.entity.mapper
|
|
|
|
def __bool__(self) -> bool:
|
|
return True
|
|
|
|
def _getitem(
|
|
self, entity: Any
|
|
) -> Union[_PathElementType, _PathRepresentation, PathRegistry]:
|
|
if isinstance(entity, (int, slice)):
|
|
return self.path[entity]
|
|
elif entity in PathToken._intern:
|
|
return TokenRegistry(self, PathToken._intern[entity])
|
|
else:
|
|
return PropRegistry(self, entity)
|
|
|
|
if not TYPE_CHECKING:
|
|
__getitem__ = _getitem
|
|
|
|
|
|
class SlotsEntityRegistry(AbstractEntityRegistry):
|
|
# for aliased class, return lightweight, no-cycles created
|
|
# version
|
|
inherit_cache = True
|
|
|
|
|
|
class _ERDict(Dict[Any, Any]):
|
|
def __init__(self, registry: CachingEntityRegistry):
|
|
self.registry = registry
|
|
|
|
def __missing__(self, key: Any) -> PropRegistry:
|
|
self[key] = item = PropRegistry(self.registry, key)
|
|
|
|
return item
|
|
|
|
|
|
class CachingEntityRegistry(AbstractEntityRegistry):
|
|
# for long lived mapper, return dict based caching
|
|
# version that creates reference cycles
|
|
|
|
__slots__ = ("_cache",)
|
|
|
|
inherit_cache = True
|
|
|
|
def __init__(
|
|
self,
|
|
parent: Union[RootRegistry, PropRegistry],
|
|
entity: _InternalEntityType[Any],
|
|
):
|
|
super().__init__(parent, entity)
|
|
self._cache = _ERDict(self)
|
|
|
|
def pop(self, key: Any, default: Any) -> Any:
|
|
return self._cache.pop(key, default)
|
|
|
|
def _getitem(self, entity: Any) -> Any:
|
|
if isinstance(entity, (int, slice)):
|
|
return self.path[entity]
|
|
elif isinstance(entity, PathToken):
|
|
return TokenRegistry(self, entity)
|
|
else:
|
|
return self._cache[entity]
|
|
|
|
if not TYPE_CHECKING:
|
|
__getitem__ = _getitem
|
|
|
|
|
|
if TYPE_CHECKING:
|
|
|
|
def path_is_entity(
|
|
path: PathRegistry,
|
|
) -> TypeGuard[AbstractEntityRegistry]: ...
|
|
|
|
def path_is_property(path: PathRegistry) -> TypeGuard[PropRegistry]: ...
|
|
|
|
else:
|
|
path_is_entity = operator.attrgetter("is_entity")
|
|
path_is_property = operator.attrgetter("is_property")
|