class UnitOfWorkTestCase(Pep8CompliantTestCase):
def set_up(self):
self._uow = UnitOfWork()
def test_basics(self):
ent = _MyEntity(id=0)
self._uow.register_new(_MyEntity, ent)
self.assert_equal(EntityState.get_state(ent).status,
ENTITY_STATUS.NEW)
self.assert_equal([item.entity for item in self._uow.iterator()],
[ent])
self.assert_equal(list(self._uow.get_new(_MyEntity)), [ent])
self._uow.mark_clean(ent)
self.assert_equal(list(self._uow.get_clean(_MyEntity)), [ent])
self._uow.mark_dirty(ent)
self.assert_equal(list(self._uow.get_dirty(_MyEntity)), [ent])
self._uow.mark_deleted(ent)
self.assert_equal(list(self._uow.get_deleted(_MyEntity)), [ent])
self._uow.unregister(_MyEntity, ent)
self.assert_equal(list(self._uow.iterator()), [])
self._uow.reset()
def test_get_state_unregistered_fails(self):
ent = _MyEntity()
with self.assert_raises(ValueError) as cm:
EntityState.get_state(ent)
msg = 'Trying to obtain state for un-managed entity'
self.assert_true(cm.exception.args[0].startswith(msg))
def test_is_marked_unregistered(self):
ent = _MyEntity()
self.assert_false(self._uow.is_marked_persisted(ent))
self.assert_false(self._uow.is_marked_pending(ent))
def test_mark_unregistered_fails(self):
ent = _MyEntity()
with self.assert_raises(ValueError) as cm:
self._uow.mark_dirty(ent)
msg = 'Trying to obtain state for un-managed entity'
self.assert_true(cm.exception.args[0].startswith(msg))
def test_release_unregistered_fails(self):
ent = _MyEntity()
with self.assert_raises(ValueError) as cm:
self._uow.unregister(_MyEntity, ent)
msg = 'Trying to unregister an entity that has not been'
self.assert_true(str(cm.exception).startswith(msg))
def test_registered_with_other_uow_fails(self):
ent = _MyEntity()
uow = UnitOfWork()
uow.register_new(_MyEntity, ent)
with self.assert_raises(ValueError) as cm1:
self._uow.register_new(_MyEntity, ent)
msg1 = 'Trying to register an entity that has been'
self.assert_true(str(cm1.exception).startswith(msg1))
with self.assert_raises(ValueError) as cm2:
self._uow.unregister(_MyEntity, ent)
msg2 = 'Trying to unregister an entity that has been'
self.assert_true(str(cm2.exception).startswith(msg2))
def test_mark_deleted_as_dirty(self):
ent = _MyEntity()
self._uow.register_new(_MyEntity, ent)
self._uow.mark_deleted(ent)
with self.assert_raises(ValueError) as cm:
self._uow.mark_dirty(ent)
msg = 'Invalid status transition'
self.assert_true(str(cm.exception).startswith(msg))
def test_check_unregistered_is_marked_new(self):
ent = _MyEntity()
self.assert_false(self._uow.is_marked_new(ent))
def test_mark_deleted_as_new(self):
ent = _MyEntity(id=0)
self._uow.register_deleted(_MyEntity, ent)
self._uow.mark_new(ent)
class MemorySession(Session):
"""
Session object.
The session
* Holds a Unit Of Work;
* Serves as identity and slug map;
* Performs synchronized commit on repository;
* Sets up data manager to hook into transaction.
"""
IS_MANAGING_BACKREFERENCES = True
def __init__(self, repository, query_class=None, clone_on_load=True):
self.__repository = repository
self.__unit_of_work = UnitOfWork()
self.__cache_map = {}
if query_class is None:
query_class = MemoryRepositoryQuery
self.__query_class = query_class
self.__clone_on_load = clone_on_load
self.__needs_flushing = False
self.__is_flushing = False
def get_by_id(self, entity_class, entity_id):
if self.__needs_flushing:
self.flush()
cache = self.__get_cache(entity_class)
return cache.get_by_id(entity_id)
def get_by_slug(self, entity_class, entity_slug):
if self.__needs_flushing:
self.flush()
cache = self.__get_cache(entity_class)
ents = cache.get_by_slug(entity_slug)
# # When the entity is not found in the cache, it may have been added
# # with an undefined slug; we therefore attempt to look it up in the
# # list of pending NEW entities.
# if ent is None:
# for new_ent in self.__unit_of_work.get_new(entity_class):
# if new_ent.slug == entity_slug:
# ent = new_ent
# break
return ents
def add(self, entity_class, data):
self.__traverse(entity_class, data, None, RELATION_OPERATIONS.ADD)
def remove(self, entity_class, data):
self.__traverse(entity_class, None, data, RELATION_OPERATIONS.REMOVE)
def update(self, entity_class, data, target=None):
return self.__traverse(entity_class, data, target,
RELATION_OPERATIONS.UPDATE)
def query(self, entity_class):
if self.__needs_flushing:
self.flush()
return self.__query_class(entity_class, self, self.__repository)
def flush(self):
if self.__needs_flushing and not self.__is_flushing:
self.__is_flushing = True
with self.__repository.lock:
self.__repository.flush(self.__unit_of_work)
self.__is_flushing = False
for ent_cls in self.__cache_map.keys():
# The flush may have auto-generated IDs for NEW entities,
# so we rebuild the cache.
cache = self.__get_cache(ent_cls)
cache.rebuild(self.__unit_of_work.get_new(ent_cls))
self.__needs_flushing = False
def begin(self):
self.__unit_of_work.reset()
def commit(self):
with self.__repository.lock:
self.__repository.commit(self.__unit_of_work)
self.__unit_of_work.reset()
self.__cache_map.clear()
def rollback(self):
with self.__repository.lock:
self.__repository.rollback(self.__unit_of_work)
self.__unit_of_work.reset()
self.__cache_map.clear()
def reset(self):
self.rollback()
def load(self, entity_class, entity):
"""
Load the given repository entity into the session and return a
clone. If it was already loaded before, look up the loaded entity
and return it.
All entities referenced by the loaded entity will also be loaded
(and cloned) recursively.
:raises ValueError: When an attempt is made to load an entity that
has no ID
"""
if self.__needs_flushing:
self.flush()
if entity.id is None:
raise ValueError('Can not load entity without an ID.')
cache = self.__get_cache(entity_class)
sess_ent = cache.get_by_id(entity.id)
if sess_ent is None:
if self.__clone_on_load:
sess_ent = self.__clone(entity, cache)
else: # Only needed by the nosql backend pragma: no cover
cache.add(entity)
sess_ent = entity
self.__unit_of_work.register_clean(entity_class, sess_ent)
return sess_ent
@property
def new(self):
return self.__unit_of_work.get_new()
@property
def deleted(self):
return self.__unit_of_work.get_deleted()
def __contains__(self, entity):
cache = self.__cache_map.get(type(entity))
if not cache is None:
found = entity in cache
else:
found = False
return found
def __traverse(self, entity_class, source_data, target_data, rel_op):
agg = self.__repository.get_aggregate(entity_class)
trv = SourceTargetDataTreeTraverser.make_traverser(source_data,
target_data,
rel_op,
accessor=agg)
vst = AruVisitor(entity_class, self.__add, self.__remove,
self.__update)
trv.run(vst)
# Indicate that we need to flush the changes.
self.__needs_flushing = True
return vst.root
def __add(self, entity):
entity_class = type(entity)
cache = self.__get_cache(entity_class)
# We allow adding the same entity multiple times.
if not (not entity.id is None
and cache.get_by_id(entity.id) is entity):
if not self.__unit_of_work.is_marked_deleted(entity):
self.__unit_of_work.register_new(entity_class, entity)
# FIXME: This is only necessary if the call above re-uses
# an existing state, in which case it needs to be
# marked as pending explicitly. Consider rewriting
# this whole method.
self.__unit_of_work.mark_pending(entity)
if not entity.id is None and cache.has_id(entity.id):
raise ValueError('Duplicate entity ID "%s".' % entity.id)
else:
if self.__unit_of_work.is_marked_pending(entity):
# The changes were not flushed yet; just mark as clean.
self.__unit_of_work.mark_clean(entity)
else:
self.__unit_of_work.mark_new(entity)
self.__unit_of_work.mark_pending(entity)
cache.add(entity)
def __remove(self, entity):
entity_class = type(entity)
if not self.__unit_of_work.is_registered(entity):
if entity.id is None:
raise ValueError('Can not remove un-registered entity '
'without an ID')
self.__unit_of_work.register_deleted(entity_class, entity)
elif not self.__unit_of_work.is_marked_new(entity):
self.__unit_of_work.mark_deleted(entity)
else:
if self.__unit_of_work.is_marked_pending(entity):
# The changes were not flushed yet; just mark as clean.
self.__unit_of_work.mark_clean(entity)
else:
self.__unit_of_work.mark_deleted(entity)
self.__unit_of_work.mark_pending(entity)
cache = self.__get_cache(entity_class)
if entity in cache:
cache.remove(entity)
def __update(self, source_data, target_entity): # pylint: disable=W0613
EntityState.set_state_data(target_entity, source_data)
if self.__unit_of_work.is_marked_persisted(target_entity):
self.__unit_of_work.mark_pending(target_entity)
def __get_cache(self, entity_class):
cache = self.__cache_map.get(entity_class)
if cache is None:
cache = self.__cache_map[entity_class] = EntityCache()
return cache
def __clone(self, entity, cache):
clone = object.__new__(entity.__class__)
# We add the clone with its ID set to the cache *before* we load it
# so that circular references will work.
clone.id = entity.id
cache.add(clone)
state = EntityState.get_state_data(entity)
id_attr = None
for attr, value in iteritems_(state):
if attr.entity_attr == 'id':
id_attr = attr
continue
attr_type = attr.attr_type
if attr.kind != RESOURCE_ATTRIBUTE_KINDS.TERMINAL \
and not self.__repository.is_registered_resource(attr_type):
# Prevent loading of entities from other repositories.
# FIXME: Doing this here is inconsistent, since e.g. the RDB
# session does not perform this kind of check.
continue
elif attr.kind == RESOURCE_ATTRIBUTE_KINDS.MEMBER \
and not value is None:
ent_cls = get_entity_class(attr_type)
new_value = self.load(ent_cls, value)
state[attr] = new_value
elif attr.kind == RESOURCE_ATTRIBUTE_KINDS.COLLECTION \
and len(value) > 0:
value_type = type(value)
new_value = value_type.__new__(value_type)
if issubclass(value_type, MutableSequence):
add_op = new_value.append
elif issubclass(value_type, MutableSet):
add_op = new_value.add
else:
raise ValueError('Do not know how to clone value of type '
'%s for resource attribute %s.' %
(type(new_value), attr))
ent_cls = get_entity_class(attr_type)
for child in value:
child_clone = self.load(ent_cls, child)
add_op(child_clone)
state[attr] = new_value
# We set the ID already above.
if not id_attr is None:
del state[id_attr]
EntityState.set_state_data(clone, state)
return clone
class UnitOfWorkTestCase(Pep8CompliantTestCase):
def set_up(self):
self._uow = UnitOfWork()
def test_basics(self):
ent = _MyEntity(id=0)
self._uow.register_new(_MyEntity, ent)
self.assert_equal(EntityState.get_state(ent).status, ENTITY_STATUS.NEW)
self.assert_equal([item.entity for item in self._uow.iterator()],
[ent])
self.assert_equal(list(self._uow.get_new(_MyEntity)), [ent])
self._uow.mark_clean(ent)
self.assert_equal(list(self._uow.get_clean(_MyEntity)), [ent])
self._uow.mark_dirty(ent)
self.assert_equal(list(self._uow.get_dirty(_MyEntity)), [ent])
self._uow.mark_deleted(ent)
self.assert_equal(list(self._uow.get_deleted(_MyEntity)), [ent])
self._uow.unregister(_MyEntity, ent)
self.assert_equal(list(self._uow.iterator()), [])
self._uow.reset()
def test_get_state_unregistered_fails(self):
ent = _MyEntity()
with self.assert_raises(ValueError) as cm:
EntityState.get_state(ent)
msg = 'Trying to obtain state for un-managed entity'
self.assert_true(cm.exception.args[0].startswith(msg))
def test_is_marked_unregistered(self):
ent = _MyEntity()
self.assert_raises(ValueError, self._uow.is_marked_persisted, ent)
self.assert_raises(ValueError, self._uow.is_marked_pending, ent)
def test_mark_unregistered_fails(self):
ent = _MyEntity()
with self.assert_raises(ValueError) as cm:
self._uow.mark_dirty(ent)
msg = 'Trying to obtain state for un-managed entity'
self.assert_true(cm.exception.args[0].startswith(msg))
def test_release_unregistered_fails(self):
ent = _MyEntity()
with self.assert_raises(ValueError) as cm:
self._uow.unregister(_MyEntity, ent)
msg = 'Trying to unregister an entity that has not been'
self.assert_true(str(cm.exception).startswith(msg))
def test_registered_with_other_uow_fails(self):
ent = _MyEntity()
uow = UnitOfWork()
uow.register_new(_MyEntity, ent)
with self.assert_raises(ValueError) as cm1:
self._uow.register_new(_MyEntity, ent)
msg1 = 'Trying to register an entity that has been'
self.assert_true(str(cm1.exception).startswith(msg1))
with self.assert_raises(ValueError) as cm2:
self._uow.unregister(_MyEntity, ent)
msg2 = 'Trying to unregister an entity that has been'
self.assert_true(str(cm2.exception).startswith(msg2))
def test_mark_deleted_as_dirty(self):
ent = _MyEntity()
self._uow.register_new(_MyEntity, ent)
self._uow.mark_deleted(ent)
with self.assert_raises(ValueError) as cm:
self._uow.mark_dirty(ent)
msg = 'Invalid status transition'
self.assert_true(str(cm.exception).startswith(msg))
def test_check_unregistered_is_marked_new(self):
ent = _MyEntity()
self.assert_false(self._uow.is_marked_new(ent))
def test_mark_deleted_as_new(self):
ent = _MyEntity(id=0)
self._uow.register_deleted(_MyEntity, ent)
self._uow.mark_new(ent)
class MemorySession(Session):
"""
Session object.
The session
* Holds a Unit Of Work;
* Serves as identity and slug map;
* Performs synchronized commit on repository;
* Sets up data manager to hook into transaction.
"""
IS_MANAGING_BACKREFERENCES = True
def __init__(self, repository, query_class=None, clone_on_load=True):
self.__repository = repository
self.__unit_of_work = UnitOfWork()
self.__cache_map = {}
if query_class is None:
query_class = MemoryRepositoryQuery
self.__query_class = query_class
self.__clone_on_load = clone_on_load
self.__needs_flushing = False
self.__is_flushing = False
def get_by_id(self, entity_class, entity_id):
if self.__needs_flushing:
self.flush()
cache = self.__get_cache(entity_class)
return cache.get_by_id(entity_id)
def get_by_slug(self, entity_class, entity_slug):
if self.__needs_flushing:
self.flush()
cache = self.__get_cache(entity_class)
ents = cache.get_by_slug(entity_slug)
# # When the entity is not found in the cache, it may have been added
# # with an undefined slug; we therefore attempt to look it up in the
# # list of pending NEW entities.
# if ent is None:
# for new_ent in self.__unit_of_work.get_new(entity_class):
# if new_ent.slug == entity_slug:
# ent = new_ent
# break
return ents
def add(self, entity_class, data):
self.__traverse(entity_class, data, None, RELATION_OPERATIONS.ADD)
def remove(self, entity_class, data):
self.__traverse(entity_class, None, data, RELATION_OPERATIONS.REMOVE)
def update(self, entity_class, data, target=None):
return self.__traverse(entity_class, data, target,
RELATION_OPERATIONS.UPDATE)
def query(self, entity_class):
if self.__needs_flushing:
self.flush()
return self.__query_class(entity_class, self, self.__repository)
def flush(self):
if self.__needs_flushing and not self.__is_flushing:
self.__is_flushing = True
with self.__repository.lock:
self.__repository.flush(self.__unit_of_work)
self.__is_flushing = False
for ent_cls in self.__cache_map.keys():
# The flush may have auto-generated IDs for NEW entities,
# so we rebuild the cache.
cache = self.__get_cache(ent_cls)
cache.rebuild(self.__unit_of_work.get_new(ent_cls))
self.__needs_flushing = False
def begin(self):
self.__unit_of_work.reset()
def commit(self):
with self.__repository.lock:
self.__repository.commit(self.__unit_of_work)
self.__unit_of_work.reset()
self.__cache_map.clear()
def rollback(self):
with self.__repository.lock:
self.__repository.rollback(self.__unit_of_work)
self.__unit_of_work.reset()
self.__cache_map.clear()
def reset(self):
self.rollback()
def load(self, entity_class, entity):
"""
Load the given repository entity into the session and return a
clone. If it was already loaded before, look up the loaded entity
and return it.
All entities referenced by the loaded entity will also be loaded
(and cloned) recursively.
:raises ValueError: When an attempt is made to load an entity that
has no ID
"""
if self.__needs_flushing:
self.flush()
if entity.id is None:
raise ValueError('Can not load entity without an ID.')
cache = self.__get_cache(entity_class)
sess_ent = cache.get_by_id(entity.id)
if sess_ent is None:
if self.__clone_on_load:
sess_ent = self.__clone(entity, cache)
else: # Only needed by the nosql backend pragma: no cover
cache.add(entity)
sess_ent = entity
self.__unit_of_work.register_clean(entity_class, sess_ent)
return sess_ent
@property
def new(self):
return self.__unit_of_work.get_new()
@property
def deleted(self):
return self.__unit_of_work.get_deleted()
def __contains__(self, entity):
cache = self.__cache_map.get(type(entity))
if not cache is None:
found = entity in cache
else:
found = False
return found
def __traverse(self, entity_class, source_data, target_data, rel_op):
agg = self.__repository.get_aggregate(entity_class)
trv = SourceTargetDataTreeTraverser.make_traverser(source_data,
target_data,
rel_op,
accessor=agg)
vst = AruVisitor(entity_class,
self.__add, self.__remove, self.__update)
trv.run(vst)
# Indicate that we need to flush the changes.
self.__needs_flushing = True
return vst.root
def __add(self, entity):
entity_class = type(entity)
cache = self.__get_cache(entity_class)
# We allow adding the same entity multiple times.
if not (not entity.id is None
and cache.get_by_id(entity.id) is entity):
if not self.__unit_of_work.is_marked_deleted(entity):
self.__unit_of_work.register_new(entity_class, entity)
# FIXME: This is only necessary if the call above re-uses
# an existing state, in which case it needs to be
# marked as pending explicitly. Consider rewriting
# this whole method.
self.__unit_of_work.mark_pending(entity)
if not entity.id is None and cache.has_id(entity.id):
raise ValueError('Duplicate entity ID "%s".' % entity.id)
else:
if self.__unit_of_work.is_marked_pending(entity):
# The changes were not flushed yet; just mark as clean.
self.__unit_of_work.mark_clean(entity)
else:
self.__unit_of_work.mark_new(entity)
self.__unit_of_work.mark_pending(entity)
cache.add(entity)
def __remove(self, entity):
entity_class = type(entity)
if not self.__unit_of_work.is_registered(entity):
if entity.id is None:
raise ValueError('Can not remove un-registered entity '
'without an ID')
self.__unit_of_work.register_deleted(entity_class, entity)
elif not self.__unit_of_work.is_marked_new(entity):
self.__unit_of_work.mark_deleted(entity)
else:
if self.__unit_of_work.is_marked_pending(entity):
# The changes were not flushed yet; just mark as clean.
self.__unit_of_work.mark_clean(entity)
else:
self.__unit_of_work.mark_deleted(entity)
self.__unit_of_work.mark_pending(entity)
cache = self.__get_cache(entity_class)
if entity in cache:
cache.remove(entity)
def __update(self, source_data, target_entity): # pylint: disable=W0613
EntityState.set_state_data(target_entity, source_data)
if self.__unit_of_work.is_marked_persisted(target_entity):
self.__unit_of_work.mark_pending(target_entity)
def __get_cache(self, entity_class):
cache = self.__cache_map.get(entity_class)
if cache is None:
cache = self.__cache_map[entity_class] = EntityCache()
return cache
def __clone(self, entity, cache):
clone = object.__new__(entity.__class__)
# We add the clone with its ID set to the cache *before* we load it
# so that circular references will work.
clone.id = entity.id
cache.add(clone)
state = EntityState.get_state_data(entity)
id_attr = None
for attr, value in iteritems_(state):
if attr.entity_attr == 'id':
id_attr = attr
continue
attr_type = attr.attr_type
if attr.kind != RESOURCE_ATTRIBUTE_KINDS.TERMINAL \
and not self.__repository.is_registered_resource(attr_type):
# Prevent loading of entities from other repositories.
# FIXME: Doing this here is inconsistent, since e.g. the RDB
# session does not perform this kind of check.
continue
elif attr.kind == RESOURCE_ATTRIBUTE_KINDS.MEMBER \
and not value is None:
ent_cls = get_entity_class(attr_type)
new_value = self.load(ent_cls, value)
state[attr] = new_value
elif attr.kind == RESOURCE_ATTRIBUTE_KINDS.COLLECTION \
and len(value) > 0:
value_type = type(value)
new_value = value_type.__new__(value_type)
if issubclass(value_type, MutableSequence):
add_op = new_value.append
elif issubclass(value_type, MutableSet):
add_op = new_value.add
else:
raise ValueError('Do not know how to clone value of type '
'%s for resource attribute %s.'
% (type(new_value), attr))
ent_cls = get_entity_class(attr_type)
for child in value:
child_clone = self.load(ent_cls, child)
add_op(child_clone)
state[attr] = new_value
# We set the ID already above.
if not id_attr is None:
del state[id_attr]
EntityState.set_state_data(clone, state)
return clone