You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
365 lines
11 KiB
365 lines
11 KiB
3 years ago
|
# sql/annotation.py
|
||
|
|
# Copyright (C) 2005-2022 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
|
||
|
|
|
||
|
|
"""The :class:`.Annotated` class and related routines; creates hash-equivalent
|
||
|
|
copies of SQL constructs which contain context-specific markers and
|
||
|
|
associations.
|
||
|
|
|
||
|
|
"""
|
||
|
|
|
||
|
|
from . import operators
|
||
|
|
from .base import HasCacheKey
|
||
|
|
from .traversals import anon_map
|
||
|
|
from .visitors import InternalTraversal
|
||
|
|
from .. import util
|
||
|
|
|
||
|
|
EMPTY_ANNOTATIONS = util.immutabledict()
|
||
|
|
|
||
|
|
|
||
|
|
class SupportsAnnotations(object):
|
||
|
|
_annotations = EMPTY_ANNOTATIONS
|
||
|
|
|
||
|
|
@util.memoized_property
|
||
|
|
def _annotations_cache_key(self):
|
||
|
|
anon_map_ = anon_map()
|
||
|
|
return (
|
||
|
|
"_annotations",
|
||
|
|
tuple(
|
||
|
|
(
|
||
|
|
key,
|
||
|
|
value._gen_cache_key(anon_map_, [])
|
||
|
|
if isinstance(value, HasCacheKey)
|
||
|
|
else value,
|
||
|
|
)
|
||
|
|
for key, value in [
|
||
|
|
(key, self._annotations[key])
|
||
|
|
for key in sorted(self._annotations)
|
||
|
|
]
|
||
|
|
),
|
||
|
|
)
|
||
|
|
|
||
|
|
|
||
|
|
class SupportsCloneAnnotations(SupportsAnnotations):
|
||
|
|
|
||
|
|
_clone_annotations_traverse_internals = [
|
||
|
|
("_annotations", InternalTraversal.dp_annotations_key)
|
||
|
|
]
|
||
|
|
|
||
|
|
def _annotate(self, values):
|
||
|
|
"""return a copy of this ClauseElement with annotations
|
||
|
|
updated by the given dictionary.
|
||
|
|
|
||
|
|
"""
|
||
|
|
new = self._clone()
|
||
|
|
new._annotations = new._annotations.union(values)
|
||
|
|
new.__dict__.pop("_annotations_cache_key", None)
|
||
|
|
new.__dict__.pop("_generate_cache_key", None)
|
||
|
|
return new
|
||
|
|
|
||
|
|
def _with_annotations(self, values):
|
||
|
|
"""return a copy of this ClauseElement with annotations
|
||
|
|
replaced by the given dictionary.
|
||
|
|
|
||
|
|
"""
|
||
|
|
new = self._clone()
|
||
|
|
new._annotations = util.immutabledict(values)
|
||
|
|
new.__dict__.pop("_annotations_cache_key", None)
|
||
|
|
new.__dict__.pop("_generate_cache_key", None)
|
||
|
|
return new
|
||
|
|
|
||
|
|
def _deannotate(self, values=None, clone=False):
|
||
|
|
"""return a copy of this :class:`_expression.ClauseElement`
|
||
|
|
with annotations
|
||
|
|
removed.
|
||
|
|
|
||
|
|
:param values: optional tuple of individual values
|
||
|
|
to remove.
|
||
|
|
|
||
|
|
"""
|
||
|
|
if clone or self._annotations:
|
||
|
|
# clone is used when we are also copying
|
||
|
|
# the expression for a deep deannotation
|
||
|
|
new = self._clone()
|
||
|
|
new._annotations = util.immutabledict()
|
||
|
|
new.__dict__.pop("_annotations_cache_key", None)
|
||
|
|
return new
|
||
|
|
else:
|
||
|
|
return self
|
||
|
|
|
||
|
|
|
||
|
|
class SupportsWrappingAnnotations(SupportsAnnotations):
|
||
|
|
def _annotate(self, values):
|
||
|
|
"""return a copy of this ClauseElement with annotations
|
||
|
|
updated by the given dictionary.
|
||
|
|
|
||
|
|
"""
|
||
|
|
return Annotated(self, values)
|
||
|
|
|
||
|
|
def _with_annotations(self, values):
|
||
|
|
"""return a copy of this ClauseElement with annotations
|
||
|
|
replaced by the given dictionary.
|
||
|
|
|
||
|
|
"""
|
||
|
|
return Annotated(self, values)
|
||
|
|
|
||
|
|
def _deannotate(self, values=None, clone=False):
|
||
|
|
"""return a copy of this :class:`_expression.ClauseElement`
|
||
|
|
with annotations
|
||
|
|
removed.
|
||
|
|
|
||
|
|
:param values: optional tuple of individual values
|
||
|
|
to remove.
|
||
|
|
|
||
|
|
"""
|
||
|
|
if clone:
|
||
|
|
s = self._clone()
|
||
|
|
return s
|
||
|
|
else:
|
||
|
|
return self
|
||
|
|
|
||
|
|
|
||
|
|
class Annotated(object):
|
||
|
|
"""clones a SupportsAnnotated and applies an 'annotations' dictionary.
|
||
|
|
|
||
|
|
Unlike regular clones, this clone also mimics __hash__() and
|
||
|
|
__cmp__() of the original element so that it takes its place
|
||
|
|
in hashed collections.
|
||
|
|
|
||
|
|
A reference to the original element is maintained, for the important
|
||
|
|
reason of keeping its hash value current. When GC'ed, the
|
||
|
|
hash value may be reused, causing conflicts.
|
||
|
|
|
||
|
|
.. note:: The rationale for Annotated producing a brand new class,
|
||
|
|
rather than placing the functionality directly within ClauseElement,
|
||
|
|
is **performance**. The __hash__() method is absent on plain
|
||
|
|
ClauseElement which leads to significantly reduced function call
|
||
|
|
overhead, as the use of sets and dictionaries against ClauseElement
|
||
|
|
objects is prevalent, but most are not "annotated".
|
||
|
|
|
||
|
|
"""
|
||
|
|
|
||
|
|
_is_column_operators = False
|
||
|
|
|
||
|
|
def __new__(cls, *args):
|
||
|
|
if not args:
|
||
|
|
# clone constructor
|
||
|
|
return object.__new__(cls)
|
||
|
|
else:
|
||
|
|
element, values = args
|
||
|
|
# pull appropriate subclass from registry of annotated
|
||
|
|
# classes
|
||
|
|
try:
|
||
|
|
cls = annotated_classes[element.__class__]
|
||
|
|
except KeyError:
|
||
|
|
cls = _new_annotation_type(element.__class__, cls)
|
||
|
|
return object.__new__(cls)
|
||
|
|
|
||
|
|
def __init__(self, element, values):
|
||
|
|
self.__dict__ = element.__dict__.copy()
|
||
|
|
self.__dict__.pop("_annotations_cache_key", None)
|
||
|
|
self.__dict__.pop("_generate_cache_key", None)
|
||
|
|
self.__element = element
|
||
|
|
self._annotations = util.immutabledict(values)
|
||
|
|
self._hash = hash(element)
|
||
|
|
|
||
|
|
def _annotate(self, values):
|
||
|
|
_values = self._annotations.union(values)
|
||
|
|
return self._with_annotations(_values)
|
||
|
|
|
||
|
|
def _with_annotations(self, values):
|
||
|
|
clone = self.__class__.__new__(self.__class__)
|
||
|
|
clone.__dict__ = self.__dict__.copy()
|
||
|
|
clone.__dict__.pop("_annotations_cache_key", None)
|
||
|
|
clone.__dict__.pop("_generate_cache_key", None)
|
||
|
|
clone._annotations = values
|
||
|
|
return clone
|
||
|
|
|
||
|
|
def _deannotate(self, values=None, clone=True):
|
||
|
|
if values is None:
|
||
|
|
return self.__element
|
||
|
|
else:
|
||
|
|
return self._with_annotations(
|
||
|
|
util.immutabledict(
|
||
|
|
{
|
||
|
|
key: value
|
||
|
|
for key, value in self._annotations.items()
|
||
|
|
if key not in values
|
||
|
|
}
|
||
|
|
)
|
||
|
|
)
|
||
|
|
|
||
|
|
def _compiler_dispatch(self, visitor, **kw):
|
||
|
|
return self.__element.__class__._compiler_dispatch(self, visitor, **kw)
|
||
|
|
|
||
|
|
@property
|
||
|
|
def _constructor(self):
|
||
|
|
return self.__element._constructor
|
||
|
|
|
||
|
|
def _clone(self, **kw):
|
||
|
|
clone = self.__element._clone(**kw)
|
||
|
|
if clone is self.__element:
|
||
|
|
# detect immutable, don't change anything
|
||
|
|
return self
|
||
|
|
else:
|
||
|
|
# update the clone with any changes that have occurred
|
||
|
|
# to this object's __dict__.
|
||
|
|
clone.__dict__.update(self.__dict__)
|
||
|
|
return self.__class__(clone, self._annotations)
|
||
|
|
|
||
|
|
def __reduce__(self):
|
||
|
|
return self.__class__, (self.__element, self._annotations)
|
||
|
|
|
||
|
|
def __hash__(self):
|
||
|
|
return self._hash
|
||
|
|
|
||
|
|
def __eq__(self, other):
|
||
|
|
if self._is_column_operators:
|
||
|
|
return self.__element.__class__.__eq__(self, other)
|
||
|
|
else:
|
||
|
|
return hash(other) == hash(self)
|
||
|
|
|
||
|
|
@property
|
||
|
|
def entity_namespace(self):
|
||
|
|
if "entity_namespace" in self._annotations:
|
||
|
|
return self._annotations["entity_namespace"].entity_namespace
|
||
|
|
else:
|
||
|
|
return self.__element.entity_namespace
|
||
|
|
|
||
|
|
|
||
|
|
# hard-generate Annotated subclasses. this technique
|
||
|
|
# is used instead of on-the-fly types (i.e. type.__new__())
|
||
|
|
# so that the resulting objects are pickleable; additionally, other
|
||
|
|
# decisions can be made up front about the type of object being annotated
|
||
|
|
# just once per class rather than per-instance.
|
||
|
|
annotated_classes = {}
|
||
|
|
|
||
|
|
|
||
|
|
def _deep_annotate(
|
||
|
|
element, annotations, exclude=None, detect_subquery_cols=False
|
||
|
|
):
|
||
|
|
"""Deep copy the given ClauseElement, annotating each element
|
||
|
|
with the given annotations dictionary.
|
||
|
|
|
||
|
|
Elements within the exclude collection will be cloned but not annotated.
|
||
|
|
|
||
|
|
"""
|
||
|
|
|
||
|
|
# annotated objects hack the __hash__() method so if we want to
|
||
|
|
# uniquely process them we have to use id()
|
||
|
|
|
||
|
|
cloned_ids = {}
|
||
|
|
|
||
|
|
def clone(elem, **kw):
|
||
|
|
kw["detect_subquery_cols"] = detect_subquery_cols
|
||
|
|
id_ = id(elem)
|
||
|
|
|
||
|
|
if id_ in cloned_ids:
|
||
|
|
return cloned_ids[id_]
|
||
|
|
|
||
|
|
if (
|
||
|
|
exclude
|
||
|
|
and hasattr(elem, "proxy_set")
|
||
|
|
and elem.proxy_set.intersection(exclude)
|
||
|
|
):
|
||
|
|
newelem = elem._clone(clone=clone, **kw)
|
||
|
|
elif annotations != elem._annotations:
|
||
|
|
if detect_subquery_cols and elem._is_immutable:
|
||
|
|
newelem = elem._clone(clone=clone, **kw)._annotate(annotations)
|
||
|
|
else:
|
||
|
|
newelem = elem._annotate(annotations)
|
||
|
|
else:
|
||
|
|
newelem = elem
|
||
|
|
newelem._copy_internals(clone=clone)
|
||
|
|
cloned_ids[id_] = newelem
|
||
|
|
return newelem
|
||
|
|
|
||
|
|
if element is not None:
|
||
|
|
element = clone(element)
|
||
|
|
clone = None # remove gc cycles
|
||
|
|
return element
|
||
|
|
|
||
|
|
|
||
|
|
def _deep_deannotate(element, values=None):
|
||
|
|
"""Deep copy the given element, removing annotations."""
|
||
|
|
|
||
|
|
cloned = {}
|
||
|
|
|
||
|
|
def clone(elem, **kw):
|
||
|
|
if values:
|
||
|
|
key = id(elem)
|
||
|
|
else:
|
||
|
|
key = elem
|
||
|
|
|
||
|
|
if key not in cloned:
|
||
|
|
newelem = elem._deannotate(values=values, clone=True)
|
||
|
|
newelem._copy_internals(clone=clone)
|
||
|
|
cloned[key] = newelem
|
||
|
|
return newelem
|
||
|
|
else:
|
||
|
|
return cloned[key]
|
||
|
|
|
||
|
|
if element is not None:
|
||
|
|
element = clone(element)
|
||
|
|
clone = None # remove gc cycles
|
||
|
|
return element
|
||
|
|
|
||
|
|
|
||
|
|
def _shallow_annotate(element, annotations):
|
||
|
|
"""Annotate the given ClauseElement and copy its internals so that
|
||
|
|
internal objects refer to the new annotated object.
|
||
|
|
|
||
|
|
Basically used to apply a "don't traverse" annotation to a
|
||
|
|
selectable, without digging throughout the whole
|
||
|
|
structure wasting time.
|
||
|
|
"""
|
||
|
|
element = element._annotate(annotations)
|
||
|
|
element._copy_internals()
|
||
|
|
return element
|
||
|
|
|
||
|
|
|
||
|
|
def _new_annotation_type(cls, base_cls):
|
||
|
|
if issubclass(cls, Annotated):
|
||
|
|
return cls
|
||
|
|
elif cls in annotated_classes:
|
||
|
|
return annotated_classes[cls]
|
||
|
|
|
||
|
|
for super_ in cls.__mro__:
|
||
|
|
# check if an Annotated subclass more specific than
|
||
|
|
# the given base_cls is already registered, such
|
||
|
|
# as AnnotatedColumnElement.
|
||
|
|
if super_ in annotated_classes:
|
||
|
|
base_cls = annotated_classes[super_]
|
||
|
|
break
|
||
|
|
|
||
|
|
annotated_classes[cls] = anno_cls = type(
|
||
|
|
"Annotated%s" % cls.__name__, (base_cls, cls), {}
|
||
|
|
)
|
||
|
|
globals()["Annotated%s" % cls.__name__] = anno_cls
|
||
|
|
|
||
|
|
if "_traverse_internals" in cls.__dict__:
|
||
|
|
anno_cls._traverse_internals = list(cls._traverse_internals) + [
|
||
|
|
("_annotations", InternalTraversal.dp_annotations_key)
|
||
|
|
]
|
||
|
|
elif cls.__dict__.get("inherit_cache", False):
|
||
|
|
anno_cls._traverse_internals = list(cls._traverse_internals) + [
|
||
|
|
("_annotations", InternalTraversal.dp_annotations_key)
|
||
|
|
]
|
||
|
|
|
||
|
|
# some classes include this even if they have traverse_internals
|
||
|
|
# e.g. BindParameter, add it if present.
|
||
|
|
if cls.__dict__.get("inherit_cache", False):
|
||
|
|
anno_cls.inherit_cache = True
|
||
|
|
|
||
|
|
anno_cls._is_column_operators = issubclass(cls, operators.ColumnOperators)
|
||
|
|
|
||
|
|
return anno_cls
|
||
|
|
|
||
|
|
|
||
|
|
def _prepare_annotations(target_hierarchy, base_cls):
|
||
|
|
for cls in util.walk_subclasses(target_hierarchy):
|
||
|
|
_new_annotation_type(cls, base_cls)
|