diff options
Diffstat (limited to 'lib/sqlalchemy/orm/session.py')
| -rw-r--r-- | lib/sqlalchemy/orm/session.py | 160 |
1 files changed, 80 insertions, 80 deletions
diff --git a/lib/sqlalchemy/orm/session.py b/lib/sqlalchemy/orm/session.py index 942b4d684..47420e207 100644 --- a/lib/sqlalchemy/orm/session.py +++ b/lib/sqlalchemy/orm/session.py @@ -138,7 +138,7 @@ def sessionmaker(bind=None, class_=None, autoflush=True, autocommit=False, :param extension: An optional :class:`~.SessionExtension` instance, or a list of such instances, which will receive pre- and post- commit and flush - events, as well as a post-rollback event. **Deprecated.** + events, as well as a post-rollback event. **Deprecated.** Please see :class:`.SessionEvents`. :param query_cls: Class which should be used to create new Query objects, @@ -190,8 +190,8 @@ def sessionmaker(bind=None, class_=None, autoflush=True, autocommit=False, Session.configure(bind=create_engine('sqlite://')) """ kwargs.update(new_kwargs) - - + + return type("Session", (Sess, class_), {}) @@ -211,9 +211,9 @@ class SessionTransaction(object): single: thread safety; SessionTransaction """ - + _rollback_exception = None - + def __init__(self, session, parent=None, nested=False): self.session = session self._connections = {} @@ -297,7 +297,7 @@ class SessionTransaction(object): for s in set(self._new).union(self.session._new): self.session._expunge_state(s) - + for s in set(self._deleted).union(self.session._deleted): if s.deleted: # assert s in self._deleted @@ -465,7 +465,7 @@ class Session(object): """Manages persistence operations for ORM-mapped objects. The Session's usage paradigm is described at :ref:`session_toplevel`. - + """ public_methods = ( @@ -475,8 +475,8 @@ class Session(object): 'is_modified', 'merge', 'query', 'refresh', 'rollback', 'scalar') - - + + def __init__(self, bind=None, autoflush=True, expire_on_commit=True, _enable_transaction_accounting=True, autocommit=False, twophase=False, @@ -489,7 +489,7 @@ class Session(object): typical point of entry. """ - + if weak_identity_map: self._identity_cls = identity.WeakInstanceDict else: @@ -509,11 +509,11 @@ class Session(object): self._enable_transaction_accounting = _enable_transaction_accounting self.twophase = twophase self._query_cls = query_cls - + if extension: for ext in util.to_list(extension): SessionExtension._adapt_listener(self, ext) - + if binds is not None: for mapperortable, bind in binds.iteritems(): if isinstance(mapperortable, (type, Mapper)): @@ -528,7 +528,7 @@ class Session(object): dispatch = event.dispatcher(SessionEvents) connection_callable = None - + def begin(self, subtransactions=False, nested=False): """Begin a transaction on this Session. @@ -537,9 +537,9 @@ class Session(object): ``subtransactions=True`` or ``nested=True`` is specified. The ``subtransactions=True`` flag indicates that this :meth:`~.Session.begin` - can create a subtransaction if a transaction is already in progress. + can create a subtransaction if a transaction is already in progress. For documentation on subtransactions, please see :ref:`session_subtransactions`. - + The ``nested`` flag begins a SAVEPOINT transaction and is equivalent to calling :meth:`~.Session.begin_nested`. For documentation on SAVEPOINT transactions, please see :ref:`session_begin_nested`. @@ -588,12 +588,12 @@ class Session(object): def commit(self): """Flush pending changes and commit the current transaction. - + If no transaction is in progress, this method raises an InvalidRequestError. - + By default, the :class:`.Session` also expires all database - loaded state on all ORM-managed attributes after transaction commit. + loaded state on all ORM-managed attributes after transaction commit. This so that subsequent operations load the most recent data from the database. This behavior can be disabled using the ``expire_on_commit=False`` option to :func:`.sessionmaker` or @@ -692,7 +692,7 @@ class Session(object): will be created for the life of the result (i.e., a connection is checked out from the connection pool, which is returned when the result object is closed). - + If the :class:`Session` is not bound to an :class:`~sqlalchemy.engine.base.Engine` or :class:`~sqlalchemy.engine.base.Connection`, the given clause will be @@ -702,7 +702,7 @@ class Session(object): (since the :class:`Session` keys multiple bind sources to a series of :func:`mapper` objects). See :meth:`get_bind` for further details on bind resolution. - + :param clause: A ClauseElement (i.e. select(), text(), etc.) or string SQL statement to be executed @@ -716,7 +716,7 @@ class Session(object): :param \**kw: Additional keyword arguments are sent to :meth:`get_bind()` which locates a connectable to use for the execution. - + """ clause = expression._literal_as_text(clause) @@ -727,7 +727,7 @@ class Session(object): def scalar(self, clause, params=None, mapper=None, **kw): """Like execute() but return a scalar result.""" - + return self.execute(clause, params=params, mapper=mapper, **kw).scalar() def close(self): @@ -826,7 +826,7 @@ class Session(object): "a binding.") c_mapper = mapper is not None and _class_to_mapper(mapper) or None - + # manually bound? if self.__binds: if c_mapper: @@ -853,7 +853,7 @@ class Session(object): context.append('mapper %s' % c_mapper) if clause is not None: context.append('SQL expression') - + raise sa_exc.UnboundExecutionError( "Could not locate a bind configured on %s or this Session" % ( ', '.join(context))) @@ -890,14 +890,14 @@ class Session(object): :meth:`~Session.refresh` usually only makes sense if non-ORM SQL statement were emitted in the ongoing transaction, or if autocommit mode is turned on. - + :param attribute_names: optional. An iterable collection of string attribute names indicating a subset of attributes to be refreshed. - + :param lockmode: Passed to the :class:`~sqlalchemy.orm.query.Query` as used by :meth:`~sqlalchemy.orm.query.Query.with_lockmode`. - + """ try: state = attributes.instance_state(instance) @@ -916,7 +916,7 @@ class Session(object): def expire_all(self): """Expires all persistent instances within this Session. - + When any attributes on a persitent instance is next accessed, a query will be issued using the :class:`.Session` object's current transactional context in order to @@ -927,7 +927,7 @@ class Session(object): To expire individual objects and individual attributes on those objects, use :meth:`Session.expire`. - + The :class:`Session` object's default behavior is to expire all state whenever the :meth:`Session.rollback` or :meth:`Session.commit` methods are called, so that new @@ -949,10 +949,10 @@ class Session(object): a highly isolated transaction will return the same values as were previously read in that same transaction, regardless of changes in database state outside of that transaction. - + To expire all objects in the :class:`.Session` simultaneously, use :meth:`Session.expire_all`. - + The :class:`Session` object's default behavior is to expire all state whenever the :meth:`Session.rollback` or :meth:`Session.commit` methods are called, so that new @@ -971,7 +971,7 @@ class Session(object): except exc.NO_STATE: raise exc.UnmappedInstanceError(instance) self._expire_state(state, attribute_names) - + def _expire_state(self, state, attribute_names): self._validate_persistent(state) if attribute_names: @@ -984,16 +984,16 @@ class Session(object): self._conditional_expire(state) for o, m, st_, dct_ in cascaded: self._conditional_expire(st_) - + def _conditional_expire(self, state): """Expire a state if persistent, else expunge if pending""" - + if state.key: state.expire(state.dict, self.identity_map._modified) elif state in self._new: self._new.pop(state) state.detach() - + def prune(self): """Remove unreferenced instances cached in the identity map. @@ -1046,7 +1046,7 @@ class Session(object): if obj is not None: instance_key = mapper._identity_key_from_state(state) - + if _none_set.issubset(instance_key[1]) and \ not mapper.allow_partial_pks or \ _none_set.issuperset(instance_key[1]): @@ -1063,10 +1063,10 @@ class Session(object): # map (see test/orm/test_naturalpks.py ReversePKsTest) self.identity_map.discard(state) state.key = instance_key - + self.identity_map.replace(state) state.commit_all(state.dict, self.identity_map) - + # remove from new last, might be the last strong ref if state in self._new: if self._enable_transaction_accounting and self.transaction: @@ -1132,7 +1132,7 @@ class Session(object): if state in self._deleted: return - + # ensure object is attached to allow the # cascade operation to load deferred attributes # and collections @@ -1164,19 +1164,19 @@ class Session(object): mapped with ``cascade="merge"``. See :ref:`unitofwork_merging` for a detailed discussion of merging. - + """ if 'dont_load' in kw: load = not kw['dont_load'] util.warn_deprecated('dont_load=True has been renamed to ' 'load=False.') - + _recursive = {} - + if load: # flush current contents if we expect to load data self._autoflush() - + _object_mapper(instance) # verify mapped autoflush = self.autoflush try: @@ -1187,7 +1187,7 @@ class Session(object): load=load, _recursive=_recursive) finally: self.autoflush = autoflush - + def _merge(self, state, state_dict, load=True, _recursive=None): mapper = _state_mapper(state) if state in _recursive: @@ -1195,7 +1195,7 @@ class Session(object): new_instance = False key = state.key - + if key is None: if not load: raise sa_exc.InvalidRequestError( @@ -1207,7 +1207,7 @@ class Session(object): if key in self.identity_map: merged = self.identity_map[key] - + elif not load: if state.modified: raise sa_exc.InvalidRequestError( @@ -1219,14 +1219,14 @@ class Session(object): merged_state.key = key self._update_impl(merged_state) new_instance = True - + elif not _none_set.issubset(key[1]) or \ (mapper.allow_partial_pks and not _none_set.issuperset(key[1])): merged = self.query(mapper.class_).get(key[1]) else: merged = None - + if merged is None: merged = mapper.class_manager.new_instance() merged_state = attributes.instance_state(merged) @@ -1236,15 +1236,15 @@ class Session(object): else: merged_state = attributes.instance_state(merged) merged_dict = attributes.instance_dict(merged) - + _recursive[state] = merged # check that we didn't just pull the exact same - # state out. + # state out. if state is not merged_state: merged_state.load_path = state.load_path merged_state.load_options = state.load_options - + for prop in mapper.iterate_properties: prop.merge(self, state, state_dict, merged_state, merged_dict, @@ -1252,7 +1252,7 @@ class Session(object): if not load: # remove any history - merged_state.commit_all(merged_dict, self.identity_map) + merged_state.commit_all(merged_dict, self.identity_map) if new_instance: merged_state.manager.dispatch.load(merged_state) @@ -1279,7 +1279,7 @@ class Session(object): raise sa_exc.InvalidRequestError( "Object '%s' already has an identity - it can't be registered " "as pending" % mapperutil.state_str(state)) - + self._attach(state) if state not in self._new: self._new[state] = state.obj() @@ -1289,12 +1289,12 @@ class Session(object): if (self.identity_map.contains_state(state) and state not in self._deleted): return - + if state.key is None: raise sa_exc.InvalidRequestError( "Instance '%s' is not persisted" % mapperutil.state_str(state)) - + if state.deleted: raise sa_exc.InvalidRequestError( "Instance '%s' has been deleted. Use the make_transient() " @@ -1317,11 +1317,11 @@ class Session(object): if state.key is None: return - + self._attach(state) self._deleted[state] = state.obj() self.identity_map.add(state) - + def _attach(self, state): if state.key and \ state.key in self.identity_map and \ @@ -1330,13 +1330,13 @@ class Session(object): "%s; another instance with key %s is already " "present in this session." % (mapperutil.state_str(state), state.key)) - + if state.session_id and state.session_id is not self.hash_key: raise sa_exc.InvalidRequestError( "Object '%s' is already attached to session '%s' " "(this is '%s')" % (mapperutil.state_str(state), state.session_id, self.hash_key)) - + if state.session_id != self.hash_key: state.session_id = self.hash_key if self.dispatch.after_attach: @@ -1393,16 +1393,16 @@ class Session(object): "The 'objects' argument to session.flush() is deprecated; " "Please do not add objects to the session which should not " "yet be persisted.") - + if self._flushing: raise sa_exc.InvalidRequestError("Session is already flushing") - + try: self._flushing = True self._flush(objects) finally: self._flushing = False - + def _flush(self, objects=None): if (not self.identity_map.check_modified() and not self._deleted and not self._new): @@ -1414,13 +1414,13 @@ class Session(object): return flush_context = UOWTransaction(self) - + if self.dispatch.before_flush: self.dispatch.before_flush(self, flush_context, objects) # re-establish "dirty states" in case the listeners # added dirty = self._dirty_states - + deleted = set(self._deleted) new = set(self._new) @@ -1448,7 +1448,7 @@ class Session(object): proc = new.union(dirty).intersection(objset).difference(deleted) else: proc = new.union(dirty).difference(deleted) - + for state in proc: is_orphan = _state_mapper(state)._is_orphan(state) and state.has_identity flush_context.register_object(state, isdelete=is_orphan) @@ -1475,7 +1475,7 @@ class Session(object): except: transaction.rollback(_capture_exception=True) raise - + flush_context.finalize_flush_changes() # useful assertions: @@ -1485,7 +1485,7 @@ class Session(object): # assert self.identity_map._modified == \ # self.identity_map._modified.difference(objects) #self.identity_map._modified.clear() - + self.dispatch.after_flush_postexec(self, flush_context) def is_modified(self, instance, include_collections=True, passive=False): @@ -1493,7 +1493,7 @@ class Session(object): This method retrieves a history instance for each instrumented attribute on the instance and performs a comparison of the current - value to its previously committed value. + value to its previously committed value. ``include_collections`` indicates if multivalued collections should be included in the operation. Setting this to False is a way to detect @@ -1503,9 +1503,9 @@ class Session(object): The ``passive`` flag indicates if unloaded attributes and collections should not be loaded in the course of performing this test. - + A few caveats to this method apply: - + * Instances present in the 'dirty' collection may result in a value of ``False`` when tested with this method. This because while the object may have received attribute set events, there may be @@ -1520,7 +1520,7 @@ class Session(object): based on the assumption that an UPDATE of the scalar value is usually needed, and in those few cases where it isn't, is less expensive on average than issuing a defensive SELECT. - + The "old" value is fetched unconditionally only if the attribute container has the "active_history" flag set to ``True``. This flag is set typically for primary key attributes and scalar references @@ -1539,10 +1539,10 @@ class Session(object): hasattr(attr.impl, 'get_collection') ) or not hasattr(attr.impl, 'get_history'): continue - + (added, unchanged, deleted) = \ attr.impl.get_history(state, dict_, passive=passive) - + if added or deleted: return True return False @@ -1604,18 +1604,18 @@ _sessions = weakref.WeakValueDictionary() def make_transient(instance): """Make the given instance 'transient'. - + This will remove its association with any session and additionally will remove its "identity key", such that it's as though the object were newly constructed, except retaining its values. It also resets the "deleted" flag on the state if this object had been explicitly deleted by its session. - + Attributes which were "expired" or deferred at the instance level are reverted to undefined, and will not trigger any loads. - + """ state = attributes.instance_state(instance) s = _state_session(state) @@ -1629,19 +1629,19 @@ def make_transient(instance): del state.key if state.deleted: del state.deleted - + def object_session(instance): """Return the ``Session`` to which instance belongs. - + If the instance is not a mapped instance, an error is raised. """ - + try: return _state_session(attributes.instance_state(instance)) except exc.NO_STATE: raise exc.UnmappedInstanceError(instance) - + def _state_session(state): if state.session_id: |