def save_or_update(self, object, entity_name=None):
"""Save or update the given object into this Session.
The presence of an `_instance_key` attribute on the instance
determines whether to ``save()`` or ``update()`` the instance.
"""
self._save_or_update_impl(object, entity_name=entity_name)
_object_mapper(object).cascade_callable('save-update', object, lambda c, e:self._save_or_update_impl(c, e), halt_on=lambda c:c in self)
def save_or_update(self, object, entity_name=None):
"""Save or update the given object into this ``Session``.
The presence of an `_instance_key` attribute on the instance
determines whether to ``save()`` or ``update()`` the instance.
"""
self._save_or_update_impl(object, entity_name=entity_name)
_object_mapper(object).cascade_callable(
'save-update',
object,
lambda c, e: self._save_or_update_impl(c, e),
halt_on=lambda c: c in self)
def save(self, object, entity_name=None):
"""Add a transient (unsaved) instance to this Session.
This operation cascades the `save_or_update` method to
associated instances if the relation is mapped with
``cascade="save-update"``.
The `entity_name` keyword argument will further qualify the
specific Mapper used to handle this instance.
"""
self._save_impl(object, entity_name=entity_name)
_object_mapper(object).cascade_callable('save-update', object, lambda c, e:self._save_or_update_impl(c, e), halt_on=lambda c:c in self)
def update(self, object, entity_name=None):
"""Bring the given detached (saved) instance into this
Session.
If there is a persistent instance with the same identifier
already associated with this Session, an exception is thrown.
This operation cascades the `save_or_update` method to
associated instances if the relation is mapped with
``cascade="save-update"``.
"""
self._update_impl(object, entity_name=entity_name)
_object_mapper(object).cascade_callable('save-update', object, lambda c, e:self._save_or_update_impl(c, e), halt_on=lambda c:c in self)
def refresh(self, instance, attribute_names=None):
"""Refresh the attributes on the given instance.
When called, a query will be issued
to the database which will refresh all attributes with their
current value.
Lazy-loaded relational attributes will remain lazily loaded, so that
the instance-wide refresh operation will be followed
immediately by the lazy load of that attribute.
Eagerly-loaded relational attributes will eagerly load within the
single refresh operation.
The ``attribute_names`` argument is an iterable collection
of attribute names indicating a subset of attributes to be
refreshed.
"""
self._validate_persistent(instance)
if (
self.query(_object_mapper(instance))._get(
instance._instance_key, refresh_instance=instance._state, only_load_props=attribute_names
)
is None
):
raise exceptions.InvalidRequestError("Could not refresh instance '%s'" % mapperutil.instance_str(instance))
def merge(self, object, entity_name=None, _recursive=None):
"""Copy the state of the given object onto the persistent
object with the same identifier.
If there is no persistent instance currently associated with
the session, it will be loaded. Return the persistent
instance. If the given instance is unsaved, save a copy of and
return it as a newly persistent instance. The given instance
does not become associated with the session.
This operation cascades to associated instances if the
association is mapped with ``cascade="merge"``.
"""
if _recursive is None:
_recursive = util.Set()
mapper = _object_mapper(object)
key = getattr(object, '_instance_key', None)
if key is None:
merged = mapper._create_instance(self)
else:
if key in self.identity_map:
merged = self.identity_map[key]
else:
merged = self.get(mapper.class_, key[1])
for prop in mapper.props.values():
prop.merge(self, object, merged, _recursive)
if key is None:
self.save(merged)
return merged
def merge(self, object, entity_name=None, _recursive=None):
"""Copy the state of the given object onto the persistent
object with the same identifier.
If there is no persistent instance currently associated with
the session, it will be loaded. Return the persistent
instance. If the given instance is unsaved, save a copy of and
return it as a newly persistent instance. The given instance
does not become associated with the session.
This operation cascades to associated instances if the
association is mapped with ``cascade="merge"``.
"""
if _recursive is None:
_recursive = util.Set()
mapper = _object_mapper(object)
key = getattr(object, '_instance_key', None)
if key is None:
merged = mapper._create_instance(self)
else:
if key in self.identity_map:
merged = self.identity_map[key]
else:
merged = self.get(mapper.class_, key[1])
for prop in mapper.props.values():
prop.merge(self, object, merged, _recursive)
if key is None:
self.save(merged)
return merged
def identity_key(cls, *args, **kwargs):
"""Get an identity key.
Valid call signatures:
* ``identity_key(class, ident, entity_name=None)``
class
mapped class (must be a positional argument)
ident
primary key, if the key is composite this is a tuple
entity_name
optional entity name
* ``identity_key(instance=instance)``
instance
object instance (must be given as a keyword arg)
* ``identity_key(class, row=row, entity_name=None)``
class
mapped class (must be a positional argument)
row
result proxy row (must be given as a keyword arg)
entity_name
optional entity name (must be given as a keyword arg)
"""
if args:
if len(args) == 1:
class_ = args[0]
try:
row = kwargs.pop("row")
except KeyError:
ident = kwargs.pop("ident")
entity_name = kwargs.pop("entity_name", None)
elif len(args) == 2:
class_, ident = args
entity_name = kwargs.pop("entity_name", None)
elif len(args) == 3:
class_, ident, entity_name = args
else:
raise exceptions.ArgumentError("expected up to three " "positional arguments, got %s" % len(args))
if kwargs:
raise exceptions.ArgumentError("unknown keyword arguments: %s" % ", ".join(kwargs.keys()))
mapper = _class_mapper(class_, entity_name=entity_name)
if "ident" in locals():
return mapper.identity_key_from_primary_key(ident)
return mapper.identity_key_from_row(row)
instance = kwargs.pop("instance")
if kwargs:
raise exceptions.ArgumentError("unknown keyword arguments: %s" % ", ".join(kwargs.keys()))
mapper = _object_mapper(instance)
return mapper.identity_key_from_instance(instance)
def identity_key(self, *args, **kwargs):
"""Get an identity key.
Valid call signatures:
identity_key(class\_, ident, entity_name=None)
class\_
mapped class (must be a positional argument)
ident
primary key, if the key is composite this is a tuple
entity_name
optional entity name
identity_key(instance=instance)
instance
object instance (must be given as a keyword arg)
identity_key(class\_, row=row, entity_name=None)
class\_
mapped class (must be a positional argument)
row
result proxy row (must be given as a keyword arg)
entity_name
optional entity name (must be given as a keyword arg)
"""
if args:
if len(args) == 1:
class_ = args[0]
try:
row = kwargs.pop("row")
except KeyError:
ident = kwargs.pop("ident")
entity_name = kwargs.pop("entity_name", None)
elif len(args) == 2:
class_, ident = args
entity_name = kwargs.pop("entity_name", None)
elif len(args) == 3:
class_, ident, entity_name = args
else:
raise exceptions.ArgumentError("expected up to three "
"positional arguments, got %s" %
len(args))
if kwargs:
raise exceptions.ArgumentError(
"unknown keyword arguments: %s" % ", ".join(kwargs.keys()))
mapper = _class_mapper(class_, entity_name=entity_name)
if "ident" in locals():
return mapper.identity_key_from_primary_key(ident)
return mapper.identity_key_from_row(row)
instance = kwargs.pop("instance")
if kwargs:
raise exceptions.ArgumentError("unknown keyword arguments: %s" %
", ".join(kwargs.keys()))
mapper = _object_mapper(instance)
return mapper.identity_key_from_instance(instance)
def save(self, object, entity_name=None):
"""Add a transient (unsaved) instance to this ``Session``.
This operation cascades the `save_or_update` method to
associated instances if the relation is mapped with
``cascade="save-update"``.
The `entity_name` keyword argument will further qualify the
specific ``Mapper`` used to handle this instance.
"""
self._save_impl(object, entity_name=entity_name)
_object_mapper(object).cascade_callable(
'save-update',
object,
lambda c, e: self._save_or_update_impl(c, e),
halt_on=lambda c: c in self)
def delete(self, object):
"""Mark the given instance as deleted.
The delete operation occurs upon ``flush()``.
"""
for c in [object] + list(_object_mapper(object).cascade_iterator('delete', object)):
self.uow.register_deleted(c)
def merge(self, instance, entity_name=None, dont_load=False, _recursive=None):
"""Copy the state of the given `instance` onto the persistent
instance with the same identifier.
If there is no persistent instance currently associated with
the session, it will be loaded. Return the persistent
instance. If the given instance is unsaved, save a copy of and
return it as a newly persistent instance. The given instance
does not become associated with the session.
This operation cascades to associated instances if the
association is mapped with ``cascade="merge"``.
"""
if _recursive is None:
_recursive = {} # TODO: this should be an IdentityDict for instances, but will need a separate
# dict for PropertyLoader tuples
if entity_name is not None:
mapper = _class_mapper(instance.__class__, entity_name=entity_name)
else:
mapper = _object_mapper(instance)
if instance in _recursive:
return _recursive[instance]
key = getattr(instance, '_instance_key', None)
if key is None:
if dont_load:
raise exceptions.InvalidRequestError("merge() with dont_load=True option does not support objects transient (i.e. unpersisted) objects. flush() all changes on mapped instances before merging with dont_load=True.")
key = mapper.identity_key_from_instance(instance)
merged = None
if key:
if key in self.identity_map:
merged = self.identity_map[key]
elif dont_load:
if instance._state.modified:
raise exceptions.InvalidRequestError("merge() with dont_load=True option does not support objects marked as 'dirty'. flush() all changes on mapped instances before merging with dont_load=True.")
merged = attributes.new_instance(mapper.class_)
merged._instance_key = key
merged._entity_name = entity_name
self._update_impl(merged, entity_name=mapper.entity_name)
else:
merged = self.get(mapper.class_, key[1])
if merged is None:
merged = attributes.new_instance(mapper.class_)
self.save(merged, entity_name=mapper.entity_name)
_recursive[instance] = merged
for prop in mapper.iterate_properties:
prop.merge(self, instance, merged, dont_load, _recursive)
if dont_load:
merged._state.commit_all() # remove any history
return merged
def expire(self, obj):
"""mark the given object as expired.
this will add an instrumentation to all mapped attributes on the instance such that when
an attribute is next accessed, the session will reload all attributes on the instance
from the database.
"""
for c in [obj] + list(_object_mapper(obj).cascade_iterator('refresh-expire', obj)):
self._expire_impl(c)
def update(self, object, entity_name=None):
"""Bring the given detached (saved) instance into this
``Session``.
If there is a persistent instance with the same identifier
already associated with this ``Session``, an exception is thrown.
This operation cascades the `save_or_update` method to
associated instances if the relation is mapped with
``cascade="save-update"``.
"""
self._update_impl(object, entity_name=entity_name)
_object_mapper(object).cascade_callable(
'save-update',
object,
lambda c, e: self._save_or_update_impl(c, e),
halt_on=lambda c: c in self)
def delete(self, object):
"""Mark the given instance as deleted.
The delete operation occurs upon ``flush()``.
"""
for c in [object] + list(
_object_mapper(object).cascade_iterator('delete', object)):
self.uow.register_deleted(c)
def expire(self, obj):
"""mark the given object as expired.
this will add an instrumentation to all mapped attributes on the instance such that when
an attribute is next accessed, the session will reload all attributes on the instance
from the database.
"""
for c in [obj] + list(
_object_mapper(obj).cascade_iterator('refresh-expire', obj)):
self._expire_impl(c)
def expunge(self, object):
"""Remove the given object from this Session.
This will free all internal references to the object.
Cascading will be applied according to the *expunge* cascade
rule.
"""
for c in [object] + list(_object_mapper(object).cascade_iterator('expunge', object)):
self.uow._remove_deleted(c)
self._unattach(c)
def expunge(self, object):
"""Remove the given `object` from this ``Session``.
This will free all internal references to the object.
Cascading will be applied according to the *expunge* cascade
rule.
"""
self._validate_persistent(object)
for c in [object] + list(_object_mapper(object).cascade_iterator('expunge', object)):
if c in self:
self.uow._remove_deleted(c)
self._unattach(c)
def expunge(self, object):
"""Remove the given object from this Session.
This will free all internal references to the object.
Cascading will be applied according to the *expunge* cascade
rule.
"""
for c in [object] + list(
_object_mapper(object).cascade_iterator('expunge', object)):
self.uow._remove_deleted(c)
self._unattach(c)
def expunge(self, object):
"""Remove the given `object` from this ``Session``.
This will free all internal references to the object.
Cascading will be applied according to the *expunge* cascade
rule.
"""
self._validate_persistent(object)
for c in [object] + list(
_object_mapper(object).cascade_iterator('expunge', object)):
if c in self:
self.uow._remove_deleted(c)
self._unattach(c)
def merge(self, object, entity_name=None, _recursive=None):
"""Copy the state of the given `object` onto the persistent
object with the same identifier.
If there is no persistent instance currently associated with
the session, it will be loaded. Return the persistent
instance. If the given instance is unsaved, save a copy of and
return it as a newly persistent instance. The given instance
does not become associated with the session.
This operation cascades to associated instances if the
association is mapped with ``cascade="merge"``.
"""
if _recursive is None:
_recursive = util.Set()
if entity_name is not None:
mapper = _class_mapper(object.__class__, entity_name=entity_name)
else:
mapper = _object_mapper(object)
if mapper in _recursive or object in _recursive:
return None
_recursive.add(mapper)
_recursive.add(object)
try:
key = getattr(object, '_instance_key', None)
if key is None:
merged = attribute_manager.new_instance(mapper.class_)
else:
if key in self.identity_map:
merged = self.identity_map[key]
else:
merged = self.get(mapper.class_, key[1])
if merged is None:
raise exceptions.AssertionError(
"Instance %s has an instance key but is not persisted"
% mapperutil.instance_str(object))
for prop in mapper.iterate_properties:
prop.merge(self, object, merged, _recursive)
if key is None:
self.save(merged, entity_name=mapper.entity_name)
return merged
finally:
_recursive.remove(mapper)
def merge(self, object, entity_name=None, _recursive=None):
"""Copy the state of the given `object` onto the persistent
object with the same identifier.
If there is no persistent instance currently associated with
the session, it will be loaded. Return the persistent
instance. If the given instance is unsaved, save a copy of and
return it as a newly persistent instance. The given instance
does not become associated with the session.
This operation cascades to associated instances if the
association is mapped with ``cascade="merge"``.
"""
if _recursive is None:
_recursive = util.Set()
if entity_name is not None:
mapper = _class_mapper(object.__class__, entity_name=entity_name)
else:
mapper = _object_mapper(object)
if mapper in _recursive or object in _recursive:
return None
_recursive.add(mapper)
_recursive.add(object)
try:
key = getattr(object, '_instance_key', None)
if key is None:
merged = mapper._create_instance(self)
else:
if key in self.identity_map:
merged = self.identity_map[key]
else:
merged = self.get(mapper.class_, key[1])
if merged is None:
raise exceptions.AssertionError("Instance %s has an instance key but is not persisted" % mapperutil.instance_str(object))
for prop in mapper.props.values():
prop.merge(self, object, merged, _recursive)
if key is None:
self.save(merged, entity_name=mapper.entity_name)
return merged
finally:
_recursive.remove(mapper)
def _cascade_iterator(cascade, instance, **kwargs):
mapper = _object_mapper(instance)
for (o, m) in mapper.cascade_iterator(cascade, instance._state, **kwargs):
yield o, m
