def __call__(self):
if not mapper.has_identity(self.instance):
return None
localparent = mapper.object_mapper(self.instance, raiseerror=False)
prop = localparent.get_property(self.key)
strategy = prop._get_strategy(DeferredColumnLoader)
if self.keys:
toload = self.keys
elif strategy.group:
toload = [p.key for p in localparent.iterate_properties if isinstance(p.strategy, DeferredColumnLoader) and p.group==strategy.group]
else:
toload = [self.key]
# narrow the keys down to just those which have no history
group = [k for k in toload if k in self.instance._state.unmodified]
if strategy._should_log_debug:
strategy.logger.debug("deferred load %s group %s" % (mapperutil.attribute_str(self.instance, self.key), group and ','.join(group) or 'None'))
session = sessionlib.object_session(self.instance)
if session is None:
raise exceptions.UnboundExecutionError("Parent instance %s is not bound to a Session; deferred load operation of attribute '%s' cannot proceed" % (self.instance.__class__, self.key))
query = session.query(localparent)
if not self.optimizing_statement:
ident = self.instance._instance_key[1]
query._get(None, ident=ident, only_load_props=group, refresh_instance=self.instance._state)
else:
statement, params = self.optimizing_statement(self.instance)
query.from_statement(statement).params(params)._get(None, only_load_props=group, refresh_instance=self.instance._state)
return attributes.ATTR_WAS_SET
def __call__(self):
if not mapper.has_identity(self.instance):
return None
localparent = mapper.object_mapper(self.instance, raiseerror=False)
prop = localparent.get_property(self.key)
strategy = prop._get_strategy(DeferredColumnLoader)
if self.keys:
toload = self.keys
elif strategy.group:
toload = [p.key for p in localparent.iterate_properties if isinstance(p.strategy, DeferredColumnLoader) and p.group==strategy.group]
else:
toload = [self.key]
# narrow the keys down to just those which have no history
group = [k for k in toload if k in self.instance._state.unmodified]
if strategy._should_log_debug:
strategy.logger.debug("deferred load %s group %s" % (mapperutil.attribute_str(self.instance, self.key), group and ','.join(group) or 'None'))
session = sessionlib.object_session(self.instance)
if session is None:
raise exceptions.UnboundExecutionError("Parent instance %s is not bound to a Session; deferred load operation of attribute '%s' cannot proceed" % (self.instance.__class__, self.key))
query = session.query(localparent)
if not self.optimizing_statement:
ident = self.instance._instance_key[1]
query._get(None, ident=ident, only_load_props=group, refresh_instance=self.instance._state)
else:
statement, params = self.optimizing_statement(self.instance)
query.from_statement(statement).params(params)._get(None, only_load_props=group, refresh_instance=self.instance._state)
return attributes.ATTR_WAS_SET
def __session(self):
sess = object_session(self.instance)
if sess is not None and self.autoflush and sess.autoflush and self.instance in sess:
sess.flush()
if not has_identity(self.instance):
return None
else:
return sess
def assign(self, collection):
instance = self.state.obj()
if has_identity(instance):
oldlist = list(self)
else:
oldlist = []
self.attr.get_history(self.state).replace(oldlist, collection)
return oldlist
def assign(self, collection):
instance = self.instance
if has_identity(instance):
oldlist = list(self)
else:
oldlist = []
self.attr._get_collection_history(self.instance._state, passive=True).replace(oldlist, collection)
return oldlist
def __session(self):
sess = object_session(self.instance)
if sess is not None and self.autoflush and sess.autoflush and self.instance in sess:
sess.flush()
if not has_identity(self.instance):
return None
else:
return sess
def assign(self, collection):
instance = self.instance
if has_identity(instance):
oldlist = list(self)
else:
oldlist = []
self.attr._get_collection(self.instance._state,
passive=True).replace(oldlist, collection)
return oldlist
def lazyload():
if self._should_log_debug:
self.logger.debug(
"lazy load attribute %s on instance %s" %
(self.key, mapperutil.instance_str(instance)))
if not mapper.has_identity(instance):
return None
session = sessionlib.object_session(instance)
if session is None:
try:
session = mapper.object_mapper(instance).get_session()
except exceptions.InvalidRequestError:
raise exceptions.InvalidRequestError(
"Parent instance %s is not bound to a Session, and no contextual session is established; lazy load operation of attribute '%s' cannot proceed"
% (instance.__class__, self.key))
# if we have a simple straight-primary key load, use mapper.get()
# to possibly save a DB round trip
q = session.query(self.mapper).autoflush(False)
if self.use_get:
params = {}
for col, bind in self.lazybinds.iteritems():
params[bind.key] = self.parent.get_attr_by_column(
instance, col)
ident = []
nonnulls = False
for primary_key in self.select_mapper.primary_key:
bind = self.lazyreverse[primary_key]
v = params[bind.key]
if v is not None:
nonnulls = True
ident.append(v)
if not nonnulls:
return None
if options:
q = q.options(*options)
return q.get(ident)
elif self.order_by is not False:
q = q.order_by(self.order_by)
elif self.secondary is not None and self.secondary.default_order_by(
) is not None:
q = q.order_by(self.secondary.default_order_by())
if options:
q = q.options(*options)
q = q.filter(self.lazy_clause(instance))
result = q.all()
if self.uselist:
return result
else:
if result:
return result[0]
else:
return None
def __session(self):
instance = self.state.obj()
sess = object_session(instance)
if sess is not None and instance in sess and sess.autoflush:
sess.flush()
if not has_identity(instance):
return None
else:
return sess
def lazyload():
if self._should_log_debug:
self.logger.debug("deferred load %s group %s" %
(mapperutil.attribute_str(
instance, self.key), str(self.group)))
if not mapper.has_identity(instance):
return None
try:
pk = self.parent.pks_by_table[self.columns[0].table]
except KeyError:
pk = self.columns[0].table.primary_key
clause = sql.and_()
for primary_key in pk:
attr = self.parent.get_attr_by_column(instance, primary_key)
if not attr:
return None
clause.clauses.append(primary_key == attr)
session = sessionlib.object_session(instance)
if session is None:
raise exceptions.InvalidRequestError(
"Parent instance %s is not bound to a Session; deferred load operation of attribute '%s' cannot proceed"
% (instance.__class__, self.key))
localparent = mapper.object_mapper(instance)
if self.group is not None:
groupcols = [
p for p in localparent.props.values()
if isinstance(p.strategy, DeferredColumnLoader)
and p.group == self.group
]
result = session.execute(
localparent,
sql.select([g.columns[0] for g in groupcols],
clause,
use_labels=True), None)
try:
row = result.fetchone()
for prop in groupcols:
if prop is self:
continue
# set a scalar object instance directly on the object,
# bypassing SmartProperty event handlers.
sessionlib.attribute_manager.init_instance_attribute(
instance, prop.key, uselist=False)
instance.__dict__[prop.key] = row[prop.columns[0]]
return row[self.columns[0]]
finally:
result.close()
else:
return session.scalar(
localparent,
sql.select([self.columns[0]], clause, use_labels=True),
None)
def __call__(self):
instance = self.instance
if not mapper.has_identity(instance):
return None
instance_mapper = mapper.object_mapper(instance)
prop = instance_mapper.get_property(self.key)
strategy = prop._get_strategy(LazyLoader)
if strategy._should_log_debug:
strategy.logger.debug("lazy load attribute %s on instance %s" % (self.key, mapperutil.instance_str(instance)))
session = sessionlib.object_session(instance)
if session is None:
try:
session = instance_mapper.get_session()
except exceptions.InvalidRequestError:
raise exceptions.UnboundExecutionError("Parent instance %s is not bound to a Session, and no contextual session is established; lazy load operation of attribute '%s' cannot proceed" % (instance.__class__, self.key))
q = session.query(prop.mapper).autoflush(False)
if self.path:
q = q._with_current_path(self.path)
# if we have a simple primary key load, use mapper.get()
# to possibly save a DB round trip
if strategy.use_get:
ident = []
allnulls = True
for primary_key in prop.mapper.primary_key:
val = instance_mapper._get_committed_attr_by_column(instance, strategy._equated_columns[primary_key])
allnulls = allnulls and val is None
ident.append(val)
if allnulls:
return None
if self.options:
q = q._conditional_options(*self.options)
return q.get(ident)
if strategy.order_by is not False:
q = q.order_by(strategy.order_by)
elif strategy.secondary is not None and strategy.secondary.default_order_by() is not None:
q = q.order_by(strategy.secondary.default_order_by())
if self.options:
q = q._conditional_options(*self.options)
q = q.filter(strategy.lazy_clause(instance))
result = q.all()
if strategy.uselist:
return result
else:
if result:
return result[0]
else:
return None
def __call__(self):
instance = self.instance
if not mapper.has_identity(instance):
return None
instance_mapper = mapper.object_mapper(instance)
prop = instance_mapper.get_property(self.key)
strategy = prop._get_strategy(LazyLoader)
if strategy._should_log_debug:
strategy.logger.debug("lazy load attribute %s on instance %s" % (self.key, mapperutil.instance_str(instance)))
session = sessionlib.object_session(instance)
if session is None:
try:
session = instance_mapper.get_session()
except exceptions.InvalidRequestError:
raise exceptions.UnboundExecutionError("Parent instance %s is not bound to a Session, and no contextual session is established; lazy load operation of attribute '%s' cannot proceed" % (instance.__class__, self.key))
q = session.query(prop.mapper).autoflush(False)
if self.path:
q = q._with_current_path(self.path)
# if we have a simple primary key load, use mapper.get()
# to possibly save a DB round trip
if strategy.use_get:
ident = []
allnulls = True
for primary_key in prop.mapper.primary_key:
val = instance_mapper._get_committed_attr_by_column(instance, strategy._equated_columns[primary_key])
allnulls = allnulls and val is None
ident.append(val)
if allnulls:
return None
if self.options:
q = q._conditional_options(*self.options)
return q.get(ident)
if strategy.order_by is not False:
q = q.order_by(strategy.order_by)
elif strategy.secondary is not None and strategy.secondary.default_order_by() is not None:
q = q.order_by(strategy.secondary.default_order_by())
if self.options:
q = q._conditional_options(*self.options)
q = q.filter(strategy.lazy_clause(instance))
result = q.all()
if strategy.uselist:
return result
else:
if result:
return result[0]
else:
return None
def lazyload():
if not mapper.has_identity(instance):
return None
if props is not None:
group = props
elif self.group is not None:
group = [
p for p in localparent.iterate_properties
if isinstance(p.strategy, DeferredColumnLoader)
and p.group == self.group
]
else:
group = [self.parent_property]
if self._should_log_debug:
self.logger.debug(
"deferred load %s group %s" %
(mapperutil.attribute_str(instance, self.key),
group and ','.join([p.key for p in group]) or 'None'))
session = sessionlib.object_session(instance)
if session is None:
raise exceptions.InvalidRequestError(
"Parent instance %s is not bound to a Session; deferred load operation of attribute '%s' cannot proceed"
% (instance.__class__, self.key))
if create_statement is None:
(clause, param_map) = localparent._get_clause
ident = instance._instance_key[1]
params = {}
for i, primary_key in enumerate(localparent.primary_key):
params[param_map[primary_key].key] = ident[i]
statement = sql.select([p.columns[0] for p in group],
clause,
from_obj=[localparent.mapped_table],
use_labels=True)
else:
statement, params = create_statement()
# TODO: have the "fetch of one row" operation go through the same channels as a query._get()
# deferred load of several attributes should be a specialized case of a query refresh operation
conn = session.connection(mapper=localparent, instance=instance)
result = conn.execute(statement, params)
try:
row = result.fetchone()
for prop in group:
sessionlib.attribute_manager.set_committed_value(
instance, prop.key, row[prop.columns[0]])
return attributes.ATTR_WAS_SET
finally:
result.close()
def lazyload():
self.logger.debug("lazy load attribute %s on instance %s" % (self.key, mapperutil.instance_str(instance)))
params = {}
allparams = True
# if the instance wasnt loaded from the database, then it cannot lazy load
# child items. one reason for this is that a bi-directional relationship
# will not update properly, since bi-directional uses lazy loading functions
# in both directions, and this instance will not be present in the lazily-loaded
# results of the other objects since its not in the database
if not mapper.has_identity(instance):
return None
#print "setting up loader, lazywhere", str(self.lazywhere), "binds", self.lazybinds
for col, bind in self.lazybinds.iteritems():
params[bind.key] = self.parent.get_attr_by_column(instance, col)
if params[bind.key] is None:
allparams = False
break
if not allparams:
return None
session = sessionlib.object_session(instance)
if session is None:
try:
session = mapper.object_mapper(instance).get_session()
except exceptions.InvalidRequestError:
raise exceptions.InvalidRequestError("Parent instance %s is not bound to a Session, and no contextual session is established; lazy load operation of attribute '%s' cannot proceed" % (instance.__class__, self.key))
# if we have a simple straight-primary key load, use mapper.get()
# to possibly save a DB round trip
if self.use_get:
ident = []
for primary_key in self.select_mapper.pks_by_table[self.select_mapper.mapped_table]:
bind = self.lazyreverse[primary_key]
ident.append(params[bind.key])
return session.query(self.mapper).get(ident)
elif self.order_by is not False:
order_by = self.order_by
elif self.secondary is not None and self.secondary.default_order_by() is not None:
order_by = self.secondary.default_order_by()
else:
order_by = False
result = session.query(self.mapper, with_options=options).select_whereclause(self.lazywhere, order_by=order_by, params=params)
if self.uselist:
return result
else:
if len(result):
return result[0]
else:
return None
def lazyload():
if self._should_log_debug:
self.logger.debug("deferred load %s group %s" % (mapperutil.attribute_str(instance, self.key), str(self.group)))
if not mapper.has_identity(instance):
return None
try:
pk = self.parent.pks_by_table[self.columns[0].table]
except KeyError:
pk = self.columns[0].table.primary_key
clause = sql.and_()
for primary_key in pk:
attr = self.parent.get_attr_by_column(instance, primary_key)
if not attr:
return None
clause.clauses.append(primary_key == attr)
session = sessionlib.object_session(instance)
if session is None:
raise exceptions.InvalidRequestError("Parent instance %s is not bound to a Session; deferred load operation of attribute '%s' cannot proceed" % (instance.__class__, self.key))
localparent = mapper.object_mapper(instance)
if self.group is not None:
groupcols = [p for p in localparent.props.values() if isinstance(p.strategy, DeferredColumnLoader) and p.group==self.group]
result = session.execute(localparent, sql.select([g.columns[0] for g in groupcols], clause, use_labels=True), None)
try:
row = result.fetchone()
for prop in groupcols:
if prop is self:
continue
# set a scalar object instance directly on the object,
# bypassing SmartProperty event handlers.
sessionlib.attribute_manager.init_instance_attribute(instance, prop.key, uselist=False)
instance.__dict__[prop.key] = row[prop.columns[0]]
return row[self.columns[0]]
finally:
result.close()
else:
return session.scalar(localparent, sql.select([self.columns[0]], clause, use_labels=True),None)
def flush(self, session, objects=None):
"""create a dependency tree of all pending SQL operations within this unit of work and execute."""
dirty = [x for x in self.identity_map.all_states()
if x.modified
or (x.class_._class_state.has_mutable_scalars and x.is_modified())
]
if not dirty and not self.deleted and not self.new:
return
deleted = util.Set(self.deleted)
new = util.Set(self.new)
dirty = util.Set(dirty).difference(deleted)
flush_context = UOWTransaction(self, session)
if session.extension is not None:
session.extension.before_flush(session, flush_context, objects)
# create the set of all objects we want to operate upon
if objects:
# specific list passed in
objset = util.Set([o._state for o in objects])
else:
# or just everything
objset = util.Set(self.identity_map.all_states()).union(new)
# store objects whose fate has been decided
processed = util.Set()
# put all saves/updates into the flush context. detect top-level orphans and throw them into deleted.
for state in new.union(dirty).intersection(objset).difference(deleted):
if state in processed:
continue
obj = state.obj()
is_orphan = _state_mapper(state)._is_orphan(obj)
if is_orphan and not has_identity(obj):
raise exceptions.FlushError("instance %s is an unsaved, pending instance and is an orphan (is not attached to %s)" %
(
obj,
", nor ".join(["any parent '%s' instance via that classes' '%s' attribute" % (klass.__name__, key) for (key,klass) in _state_mapper(state).delete_orphans])
))
flush_context.register_object(state, isdelete=is_orphan)
processed.add(state)
# put all remaining deletes into the flush context.
for state in deleted.intersection(objset).difference(processed):
flush_context.register_object(state, isdelete=True)
if len(flush_context.tasks) == 0:
return
session.create_transaction(autoflush=False)
flush_context.transaction = session.transaction
try:
flush_context.execute()
if session.extension is not None:
session.extension.after_flush(session, flush_context)
session.commit()
except:
session.rollback()
raise
for state in deleted.intersection(objset):
state.is_deleted = True
flush_context.post_exec()
if session.extension is not None:
session.extension.after_flush_postexec(session, flush_context)
def lazyload():
self.logger.debug("lazy load attribute %s on instance %s" %
(self.key, mapperutil.instance_str(instance)))
params = {}
allparams = True
# if the instance wasnt loaded from the database, then it cannot lazy load
# child items. one reason for this is that a bi-directional relationship
# will not update properly, since bi-directional uses lazy loading functions
# in both directions, and this instance will not be present in the lazily-loaded
# results of the other objects since its not in the database
if not mapper.has_identity(instance):
return None
#print "setting up loader, lazywhere", str(self.lazywhere), "binds", self.lazybinds
for col, bind in self.lazybinds.iteritems():
params[bind.key] = self.parent.get_attr_by_column(
instance, col)
if params[bind.key] is None:
allparams = False
break
if not allparams:
return None
session = sessionlib.object_session(instance)
if session is None:
try:
session = mapper.object_mapper(instance).get_session()
except exceptions.InvalidRequestError:
raise exceptions.InvalidRequestError(
"Parent instance %s is not bound to a Session, and no contextual session is established; lazy load operation of attribute '%s' cannot proceed"
% (instance.__class__, self.key))
# if we have a simple straight-primary key load, use mapper.get()
# to possibly save a DB round trip
if self.use_get:
ident = []
for primary_key in self.select_mapper.pks_by_table[
self.select_mapper.mapped_table]:
bind = self.lazyreverse[primary_key]
ident.append(params[bind.key])
return session.query(self.mapper).get(ident)
elif self.order_by is not False:
order_by = self.order_by
elif self.secondary is not None and self.secondary.default_order_by(
) is not None:
order_by = self.secondary.default_order_by()
else:
order_by = False
result = session.query(self.mapper,
with_options=options).select_whereclause(
self.lazywhere,
order_by=order_by,
params=params)
if self.uselist:
return result
else:
if len(result):
return result[0]
else:
return None
def flush(self, session, objects=None):
"""create a dependency tree of all pending SQL operations within this unit of work and execute."""
dirty = [x for x in self.identity_map.all_states()
if x.modified
or (x.class_._class_state.has_mutable_scalars and x.is_modified())
]
if not dirty and not self.deleted and not self.new:
return
deleted = util.Set(self.deleted)
new = util.Set(self.new)
dirty = util.Set(dirty).difference(deleted)
flush_context = UOWTransaction(self, session)
if session.extension is not None:
session.extension.before_flush(session, flush_context, objects)
# create the set of all objects we want to operate upon
if objects:
# specific list passed in
objset = util.Set([o._state for o in objects])
else:
# or just everything
objset = util.Set(self.identity_map.all_states()).union(new)
# store objects whose fate has been decided
processed = util.Set()
# put all saves/updates into the flush context. detect top-level orphans and throw them into deleted.
for state in new.union(dirty).intersection(objset).difference(deleted):
if state in processed:
continue
obj = state.obj()
is_orphan = _state_mapper(state)._is_orphan(obj)
if is_orphan and not has_identity(obj):
raise exceptions.FlushError("instance %s is an unsaved, pending instance and is an orphan (is not attached to %s)" %
(
obj,
", nor ".join(["any parent '%s' instance via that classes' '%s' attribute" % (klass.__name__, key) for (key,klass) in _state_mapper(state).delete_orphans])
))
flush_context.register_object(state, isdelete=is_orphan)
processed.add(state)
# put all remaining deletes into the flush context.
for state in deleted.intersection(objset).difference(processed):
flush_context.register_object(state, isdelete=True)
if len(flush_context.tasks) == 0:
return
session.create_transaction(autoflush=False)
flush_context.transaction = session.transaction
try:
flush_context.execute()
if session.extension is not None:
session.extension.after_flush(session, flush_context)
session.commit()
except:
session.rollback()
raise
flush_context.post_exec()
if session.extension is not None:
session.extension.after_flush_postexec(session, flush_context)
