diff options
Diffstat (limited to 'lib/sqlalchemy/orm/util.py')
| -rw-r--r-- | lib/sqlalchemy/orm/util.py | 429 |
1 files changed, 7 insertions, 422 deletions
diff --git a/lib/sqlalchemy/orm/util.py b/lib/sqlalchemy/orm/util.py index ae1ca2013..d10a78dd7 100644 --- a/lib/sqlalchemy/orm/util.py +++ b/lib/sqlalchemy/orm/util.py @@ -7,21 +7,19 @@ from .. import sql, util, event, exc as sa_exc, inspection from ..sql import expression, util as sql_util, operators -from .interfaces import PropComparator, MapperProperty, _InspectionAttr -from itertools import chain -from . import attributes, exc +from .interfaces import PropComparator, MapperProperty +from . import attributes import re -mapperlib = util.importlater("sqlalchemy.orm", "mapperlib") +from .base import instance_str, state_str, state_class_str, attribute_str, \ + state_attribute_str, object_mapper, object_state, _none_set +from .base import class_mapper, _class_to_mapper +from .base import _InspectionAttr all_cascades = frozenset(("delete", "delete-orphan", "all", "merge", "expunge", "save-update", "refresh-expire", "none")) -_INSTRUMENTOR = ('mapper', 'instrumentor') - -_none_set = frozenset([None]) - class CascadeOptions(frozenset): """Keeps track of the options sent to relationship().cascade""" @@ -245,211 +243,7 @@ class ORMAdapter(sql_util.ColumnAdapter): else: return None -def _unreduce_path(path): - return PathRegistry.deserialize(path) - -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 isinstance(path_mapper, mapperlib.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) - - @classmethod - def token(cls, token): - return TokenRegistry(cls.root, 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 = () - - 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,) - - 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,) - - 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 - - def __init__(self, parent, entity): - self.key = entity - self.parent = parent - self.is_aliased_class = entity.is_aliased_class - - self.path = parent.path + (entity,) - - 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 _inlined_get_for(self, prop, context, key): - """an inlined version of: - - cls = path[mapperproperty].get(context, key) - - Skips the isinstance() check in __getitem__ - and the extra method call for get(). - Used by StrategizedProperty for its - very frequent lookup. - - """ - path = dict.__getitem__(self, prop) - path_key = (key, path.path) - if path_key in context.attributes: - return context.attributes[path_key] - else: - return None - - def __missing__(self, key): - self[key] = item = PropRegistry(self, key) - return item - +from .path_registry import _unreduce_path, PathRegistry, RootRegistry, TokenRegistry, PropRegistry, EntityRegistry class AliasedClass(object): """Represents an "aliased" form of a mapped class for usage with Query. @@ -1053,186 +847,6 @@ def with_parent(instance, prop): value_is_parent=True) -def _attr_as_key(attr): - if hasattr(attr, 'key'): - return attr.key - else: - return expression._column_as_key(attr) - - -_state_mapper = util.dottedgetter('manager.mapper') - - -@inspection._inspects(object) -def _inspect_mapped_object(instance): - try: - return attributes.instance_state(instance) - # TODO: whats the py-2/3 syntax to catch two - # different kinds of exceptions at once ? - except exc.UnmappedClassError: - return None - except exc.NO_STATE: - return None - - -@inspection._inspects(type) -def _inspect_mapped_class(class_, configure=False): - try: - class_manager = attributes.manager_of_class(class_) - if not class_manager.is_mapped: - return None - mapper = class_manager.mapper - if configure and mapperlib.module._new_mappers: - mapperlib.configure_mappers() - return mapper - - except exc.NO_STATE: - return None - - -def object_mapper(instance): - """Given an object, return the primary Mapper associated with the object - instance. - - Raises :class:`sqlalchemy.orm.exc.UnmappedInstanceError` - if no mapping is configured. - - This function is available via the inspection system as:: - - inspect(instance).mapper - - Using the inspection system will raise - :class:`sqlalchemy.exc.NoInspectionAvailable` if the instance is - not part of a mapping. - - """ - return object_state(instance).mapper - - -def object_state(instance): - """Given an object, return the :class:`.InstanceState` - associated with the object. - - Raises :class:`sqlalchemy.orm.exc.UnmappedInstanceError` - if no mapping is configured. - - Equivalent functionality is available via the :func:`.inspect` - function as:: - - inspect(instance) - - Using the inspection system will raise - :class:`sqlalchemy.exc.NoInspectionAvailable` if the instance is - not part of a mapping. - - """ - state = _inspect_mapped_object(instance) - if state is None: - raise exc.UnmappedInstanceError(instance) - else: - return state - - -def class_mapper(class_, configure=True): - """Given a class, return the primary :class:`.Mapper` associated - with the key. - - Raises :class:`.UnmappedClassError` if no mapping is configured - on the given class, or :class:`.ArgumentError` if a non-class - object is passed. - - Equivalent functionality is available via the :func:`.inspect` - function as:: - - inspect(some_mapped_class) - - Using the inspection system will raise - :class:`sqlalchemy.exc.NoInspectionAvailable` if the class is not mapped. - - """ - mapper = _inspect_mapped_class(class_, configure=configure) - if mapper is None: - if not isinstance(class_, type): - raise sa_exc.ArgumentError( - "Class object expected, got '%r'." % class_) - raise exc.UnmappedClassError(class_) - else: - return mapper - - -def _class_to_mapper(class_or_mapper): - insp = inspection.inspect(class_or_mapper, False) - if insp is not None: - return insp.mapper - else: - raise exc.UnmappedClassError(class_or_mapper) - - -def _mapper_or_none(entity): - """Return the :class:`.Mapper` for the given class or None if the - class is not mapped.""" - - insp = inspection.inspect(entity, False) - if insp is not None: - return insp.mapper - else: - return None - - -def _is_mapped_class(entity): - """Return True if the given object is a mapped class, - :class:`.Mapper`, or :class:`.AliasedClass`.""" - - insp = inspection.inspect(entity, False) - return insp is not None and \ - hasattr(insp, "mapper") and \ - ( - insp.is_mapper - or insp.is_aliased_class - ) - - -def _is_aliased_class(entity): - insp = inspection.inspect(entity, False) - return insp is not None and \ - getattr(insp, "is_aliased_class", False) - - -def _entity_descriptor(entity, key): - """Return a class attribute given an entity and string name. - - May return :class:`.InstrumentedAttribute` or user-defined - attribute. - - """ - insp = inspection.inspect(entity) - if insp.is_selectable: - description = entity - entity = insp.c - elif insp.is_aliased_class: - entity = insp.entity - description = entity - elif hasattr(insp, "mapper"): - description = entity = insp.mapper.class_ - else: - description = entity - - try: - return getattr(entity, key) - except AttributeError: - raise sa_exc.InvalidRequestError( - "Entity '%s' has no property '%s'" % - (description, key) - ) - - -def _orm_columns(entity): - insp = inspection.inspect(entity, False) - if hasattr(insp, 'selectable'): - return [c for c in insp.selectable.c] - else: - return [entity] - def has_identity(object): """Return True if the given object has a database @@ -1260,36 +874,7 @@ def was_deleted(object): state = attributes.instance_state(object) return state.deleted -def instance_str(instance): - """Return a string describing an instance.""" - - return state_str(attributes.instance_state(instance)) - - -def state_str(state): - """Return a string describing an instance via its InstanceState.""" - - if state is None: - return "None" - else: - return '<%s at 0x%x>' % (state.class_.__name__, id(state.obj())) - - -def state_class_str(state): - """Return a string describing an instance's class via its InstanceState.""" - - if state is None: - return "None" - else: - return '<%s>' % (state.class_.__name__, ) - - -def attribute_str(instance, attribute): - return instance_str(instance) + "." + attribute - -def state_attribute_str(state, attribute): - return state_str(state) + "." + attribute def randomize_unitofwork(): |