Implement load_module function

Change-Id: Ia5640962fbece169501838a410fb5ac36e8f360b
This commit is contained in:
Federico Ressi 2019-01-14 14:33:52 +01:00
parent 160da96973
commit 75d5825610
3 changed files with 107 additions and 40 deletions

View File

@ -18,6 +18,7 @@ from tobiko.common.managers import loader as loader_manager
load_object = loader_manager.load_object
load_module = loader_manager.load_module
Fixture = fixture_manager.Fixture

View File

@ -19,15 +19,18 @@ import weakref
import sys
_REF_TO_NONE = object()
def load_object(object_id, manager=None, new_loader=None, cached=True):
manager = manager or LOADERS
loader = manager.get_loader(object_id=object_id, new_loader=new_loader)
return loader.load(manager=manager, cached=cached)
def load_module(object_id, manager=None, new_loader=None, cached=True):
manager = manager or LOADERS
loader = manager.get_loader(object_id=object_id, new_loader=new_loader)
return loader.load_module(manager=manager, cached=cached)
class ObjectLoader(object):
"""Previously loaded object meta-data"""
@ -58,25 +61,45 @@ class ObjectLoader(object):
def id(self):
return self._id
def set(self, obj):
if obj is None:
self._is_module = False
self.get = self._get_none
elif inspect.ismodule(obj):
# Cannot create weak reference to modules on Python2
self._is_module = True
self.get = self._get_module
else:
self._is_module = False
self._ref = weakref.ref(obj)
self.get = self._get_object
def __repr__(self):
return '{cls!s}({id!r})'.format(cls=type(self).__name__, id=self._id)
def get(self):
if self._is_module:
return sys.modules.get(self._id)
ref = self._ref
if ref is _REF_TO_NONE:
return None
if callable(ref):
obj = ref()
if obj is not None:
return obj
def _get_not_cached(self):
msg = "Object {!r} not cached".format(self._id)
raise RuntimeError(msg)
get = _get_not_cached
@staticmethod
def _get_none():
return None
def _get_module(self):
try:
return sys.modules[self._id]
except KeyError:
pass
return self._get_not_cached()
def _get_object(self):
obj = self._ref()
if obj is None:
return self._get_not_cached()
return obj
def load(self, manager, cached=True):
if cached:
try:
@ -84,35 +107,52 @@ class ObjectLoader(object):
except RuntimeError:
pass
obj = None
parent_id = self._parent_id
if parent_id:
parent_loader = manager.get_loader(object_id=parent_id,
new_loader=type(self))
parent_loader = self.get_parent(manager=manager)
if parent_loader:
parent = parent_loader.load(manager=manager, cached=cached)
name = self._name
try:
obj = getattr(parent, name)
except AttributeError:
if not parent_loader.is_module:
if parent_loader.is_module:
return self._load_module()
else:
# Child cannot be a module if parent isn't a module
raise
else:
if obj is None:
# Cannot create weak reference to None
self._ref = _REF_TO_NONE
elif inspect.ismodule(obj):
# Cannot create weak reference to Module
self._is_module = True
else:
self._ref = weakref.ref(obj)
self.set(obj)
return obj
else:
# Root objects can only be modules
return self._load_module()
if obj is None:
obj = importlib.import_module(self._id)
self._is_module = True
def _load_module(self):
obj = importlib.import_module(self._id)
self.set(obj)
return obj
def get_parent(self, manager):
parent_id = self._parent_id
if parent_id:
return manager.get_loader(object_id=parent_id)
else:
return None
def load_module(self, manager, cached=True):
if cached and self._is_module:
return self.get()
self.load(manager=manager, cached=cached)
if self._is_module:
return self.get()
parent = self.get_parent(manager=manager)
if parent:
return parent.load_module(manager=manager, cached=True)
msg = ("Non-module object {!r} has no parent").format(self._id)
raise RuntimeError(msg)
class LoaderManager(object):
@ -136,8 +176,7 @@ class LoaderManager(object):
new_loader = new_loader or self.new_loader
loader = new_loader(object_id=object_id)
if not isinstance(loader, ObjectLoader):
msg = "{!r} is not instance of class ObjectLoader".format(
loader)
msg = "{!r} is not instance of class ObjectLoader".format(loader)
raise TypeError(msg)
self._loaders[object_id] = loader

View File

@ -47,6 +47,11 @@ class TestLoader(TobikoUnitTest):
self.assertIs(_loader.get(), obj)
self.assertIs(_loader, self.manager.get_loader(object_id))
def test_load_module_with_none(self):
object_id = '.'.join([__name__, 'SOME_NONE'])
module = tobiko.load_module(object_id)
self.assertEqual(__name__, module.__name__)
def test_load_object_with_module(self):
object_id = __name__
obj = tobiko.load_object(object_id)
@ -58,17 +63,22 @@ class TestLoader(TobikoUnitTest):
self.assertIs(_loader.get(), obj)
self.assertIs(_loader, self.manager.get_loader(object_id))
def test_load_module_with_module(self):
object_id = __name__
module = tobiko.load_module(object_id)
self.assertEqual(__name__, module.__name__)
def test_load_object_with_class(self):
object_id = '.'.join([SomeClass.__module__,
SomeClass.__name__])
obj = tobiko.load_object(object_id)
self.assertIs(SomeClass, obj)
_loader = self.manager.get_loader(object_id)
self.assertEqual(_loader.id, object_id)
self.assertFalse(_loader.is_module)
self.assertIs(_loader.get(), obj)
self.assertIs(_loader, self.manager.get_loader(object_id))
def test_load_module_with_class(self):
object_id = '.'.join([SomeClass.__module__,
SomeClass.__name__])
module = tobiko.load_module(object_id)
self.assertEqual(__name__, module.__name__)
def test_load_object_with_class_method(self):
object_id = '.'.join([SomeClass.__module__,
@ -83,12 +93,29 @@ class TestLoader(TobikoUnitTest):
self.assertIs(_loader.get(), obj)
self.assertIs(_loader, self.manager.get_loader(object_id))
def test_load_module_with_class_method(self):
object_id = '.'.join([SomeClass.__module__,
SomeClass.__name__,
SomeClass.some_method.__name__])
module = tobiko.load_module(object_id)
self.assertEqual(__name__, module.__name__)
def test_load_object_with_non_existing(self):
object_id = '.'.join([SomeClass.__module__, '<non-existing>'])
self.assertRaises(ImportError, tobiko.load_object, object_id)
def test_load_module_with_non_existing(self):
object_id = '.'.join([SomeClass.__module__, '<non-existing>'])
self.assertRaises(ImportError, tobiko.load_module, object_id)
def test_load_object_with_non_existing_member(self):
object_id = '.'.join([SomeClass.__module__,
SomeClass.__name__,
'<non-existing>'])
self.assertRaises(AttributeError, tobiko.load_object, object_id)
def test_load_module_with_non_existing_member(self):
object_id = '.'.join([SomeClass.__module__,
SomeClass.__name__,
'<non-existing>'])
self.assertRaises(AttributeError, tobiko.load_module, object_id)