mirror of
https://github.com/moparisthebest/SickRage
synced 2024-11-06 01:15:05 -05:00
262 lines
7.5 KiB
Python
262 lines
7.5 KiB
Python
# orm/path_registry.py
|
|
# Copyright (C) 2005-2014 the SQLAlchemy authors and contributors <see AUTHORS file>
|
|
#
|
|
# This module is part of SQLAlchemy and is released under
|
|
# the MIT License: http://www.opensource.org/licenses/mit-license.php
|
|
"""Path tracking utilities, representing mapper graph traversals.
|
|
|
|
"""
|
|
|
|
from .. import inspection
|
|
from .. import util
|
|
from .. import exc
|
|
from itertools import chain
|
|
from .base import class_mapper
|
|
|
|
def _unreduce_path(path):
|
|
return PathRegistry.deserialize(path)
|
|
|
|
|
|
_WILDCARD_TOKEN = "*"
|
|
_DEFAULT_TOKEN = "_sa_default"
|
|
|
|
class PathRegistry(object):
|
|
"""Represent query load paths and registry functions.
|
|
|
|
Basically represents structures like:
|
|
|
|
(<User mapper>, "orders", <Order mapper>, "items", <Item mapper>)
|
|
|
|
These structures are generated by things like
|
|
query options (joinedload(), subqueryload(), etc.) and are
|
|
used to compose keys stored in the query._attributes dictionary
|
|
for various options.
|
|
|
|
They are then re-composed at query compile/result row time as
|
|
the query is formed and as rows are fetched, where they again
|
|
serve to compose keys to look up options in the context.attributes
|
|
dictionary, which is copied from query._attributes.
|
|
|
|
The path structure has a limited amount of caching, where each
|
|
"root" ultimately pulls from a fixed registry associated with
|
|
the first mapper, that also contains elements for each of its
|
|
property keys. However paths longer than two elements, which
|
|
are the exception rather than the rule, are generated on an
|
|
as-needed basis.
|
|
|
|
"""
|
|
|
|
def __eq__(self, other):
|
|
return other is not None and \
|
|
self.path == other.path
|
|
|
|
def set(self, attributes, key, value):
|
|
attributes[(key, self.path)] = value
|
|
|
|
def setdefault(self, attributes, key, value):
|
|
attributes.setdefault((key, self.path), value)
|
|
|
|
def get(self, attributes, key, value=None):
|
|
key = (key, self.path)
|
|
if key in attributes:
|
|
return attributes[key]
|
|
else:
|
|
return value
|
|
|
|
def __len__(self):
|
|
return len(self.path)
|
|
|
|
@property
|
|
def length(self):
|
|
return len(self.path)
|
|
|
|
def pairs(self):
|
|
path = self.path
|
|
for i in range(0, len(path), 2):
|
|
yield path[i], path[i + 1]
|
|
|
|
def contains_mapper(self, mapper):
|
|
for path_mapper in [
|
|
self.path[i] for i in range(0, len(self.path), 2)
|
|
]:
|
|
if path_mapper.is_mapper and \
|
|
path_mapper.isa(mapper):
|
|
return True
|
|
else:
|
|
return False
|
|
|
|
def contains(self, attributes, key):
|
|
return (key, self.path) in attributes
|
|
|
|
def __reduce__(self):
|
|
return _unreduce_path, (self.serialize(), )
|
|
|
|
def serialize(self):
|
|
path = self.path
|
|
return list(zip(
|
|
[m.class_ for m in [path[i] for i in range(0, len(path), 2)]],
|
|
[path[i].key for i in range(1, len(path), 2)] + [None]
|
|
))
|
|
|
|
@classmethod
|
|
def deserialize(cls, path):
|
|
if path is None:
|
|
return None
|
|
|
|
p = tuple(chain(*[(class_mapper(mcls),
|
|
class_mapper(mcls).attrs[key]
|
|
if key is not None else None)
|
|
for mcls, key in path]))
|
|
if p and p[-1] is None:
|
|
p = p[0:-1]
|
|
return cls.coerce(p)
|
|
|
|
@classmethod
|
|
def per_mapper(cls, mapper):
|
|
return EntityRegistry(
|
|
cls.root, mapper
|
|
)
|
|
|
|
@classmethod
|
|
def coerce(cls, raw):
|
|
return util.reduce(lambda prev, next: prev[next], raw, cls.root)
|
|
|
|
def token(self, token):
|
|
if token.endswith(':' + _WILDCARD_TOKEN):
|
|
return TokenRegistry(self, token)
|
|
elif token.endswith(":" + _DEFAULT_TOKEN):
|
|
return TokenRegistry(self.root, token)
|
|
else:
|
|
raise exc.ArgumentError("invalid token: %s" % token)
|
|
|
|
def __add__(self, other):
|
|
return util.reduce(
|
|
lambda prev, next: prev[next],
|
|
other.path, self)
|
|
|
|
def __repr__(self):
|
|
return "%s(%r)" % (self.__class__.__name__, self.path, )
|
|
|
|
|
|
class RootRegistry(PathRegistry):
|
|
"""Root registry, defers to mappers so that
|
|
paths are maintained per-root-mapper.
|
|
|
|
"""
|
|
path = ()
|
|
has_entity = False
|
|
def __getitem__(self, entity):
|
|
return entity._path_registry
|
|
|
|
PathRegistry.root = RootRegistry()
|
|
|
|
class TokenRegistry(PathRegistry):
|
|
def __init__(self, parent, token):
|
|
self.token = token
|
|
self.parent = parent
|
|
self.path = parent.path + (token,)
|
|
|
|
has_entity = False
|
|
|
|
def __getitem__(self, entity):
|
|
raise NotImplementedError()
|
|
|
|
class PropRegistry(PathRegistry):
|
|
def __init__(self, parent, prop):
|
|
# restate this path in terms of the
|
|
# given MapperProperty's parent.
|
|
insp = inspection.inspect(parent[-1])
|
|
if not insp.is_aliased_class or insp._use_mapper_path:
|
|
parent = parent.parent[prop.parent]
|
|
elif insp.is_aliased_class and insp.with_polymorphic_mappers:
|
|
if prop.parent is not insp.mapper and \
|
|
prop.parent in insp.with_polymorphic_mappers:
|
|
subclass_entity = parent[-1]._entity_for_mapper(prop.parent)
|
|
parent = parent.parent[subclass_entity]
|
|
|
|
self.prop = prop
|
|
self.parent = parent
|
|
self.path = parent.path + (prop,)
|
|
|
|
@util.memoized_property
|
|
def has_entity(self):
|
|
return hasattr(self.prop, "mapper")
|
|
|
|
@util.memoized_property
|
|
def entity(self):
|
|
return self.prop.mapper
|
|
|
|
@util.memoized_property
|
|
def _wildcard_path_loader_key(self):
|
|
"""Given a path (mapper A, prop X), replace the prop with the wildcard,
|
|
e.g. (mapper A, 'relationship:.*') or (mapper A, 'column:.*'), then
|
|
return within the ("loader", path) structure.
|
|
|
|
"""
|
|
return ("loader",
|
|
self.parent.token(
|
|
"%s:%s" % (self.prop.strategy_wildcard_key, _WILDCARD_TOKEN)
|
|
).path
|
|
)
|
|
|
|
@util.memoized_property
|
|
def _default_path_loader_key(self):
|
|
return ("loader",
|
|
self.parent.token(
|
|
"%s:%s" % (self.prop.strategy_wildcard_key, _DEFAULT_TOKEN)
|
|
).path
|
|
)
|
|
|
|
@util.memoized_property
|
|
def _loader_key(self):
|
|
return ("loader", self.path)
|
|
|
|
@property
|
|
def mapper(self):
|
|
return self.entity
|
|
|
|
@property
|
|
def entity_path(self):
|
|
return self[self.entity]
|
|
|
|
def __getitem__(self, entity):
|
|
if isinstance(entity, (int, slice)):
|
|
return self.path[entity]
|
|
else:
|
|
return EntityRegistry(
|
|
self, entity
|
|
)
|
|
|
|
class EntityRegistry(PathRegistry, dict):
|
|
is_aliased_class = False
|
|
has_entity = True
|
|
|
|
def __init__(self, parent, entity):
|
|
self.key = entity
|
|
self.parent = parent
|
|
self.is_aliased_class = entity.is_aliased_class
|
|
self.entity = entity
|
|
self.path = parent.path + (entity,)
|
|
self.entity_path = self
|
|
|
|
@property
|
|
def mapper(self):
|
|
return inspection.inspect(self.entity).mapper
|
|
|
|
def __bool__(self):
|
|
return True
|
|
__nonzero__ = __bool__
|
|
|
|
def __getitem__(self, entity):
|
|
if isinstance(entity, (int, slice)):
|
|
return self.path[entity]
|
|
else:
|
|
return dict.__getitem__(self, entity)
|
|
|
|
def __missing__(self, key):
|
|
self[key] = item = PropRegistry(self, key)
|
|
return item
|
|
|
|
|
|
|