"""Containers module.""" import json import sys try: import asyncio except ImportError: asyncio = None try: import yaml except ImportError: yaml = None import six from . import providers, errors from .providers cimport __is_future_or_coroutine if sys.version_info[:2] >= (3, 6): from .wiring import wire, unwire else: def wire(*args, **kwargs): raise NotImplementedError('Wiring requires Python 3.6 or above') def unwire(*args, **kwargs): raise NotImplementedError('Wiring requires Python 3.6 or above') class Container(object): """Abstract container.""" class DynamicContainer(Container): """Dynamic inversion of control container. .. code-block:: python services = DynamicContainer() services.auth = providers.Factory(AuthService) services.users = providers.Factory(UsersService, auth_service=services.auth) .. py:attribute:: providers Read-only dictionary of all providers. :type: dict[str, :py:class:`dependency_injector.providers.Provider`] .. py:attribute:: overridden Tuple of overriding containers. :type: tuple[:py:class:`DynamicContainer`] .. py:attribute:: provider_type Type of providers that could be placed in container. :type: type """ __IS_CONTAINER__ = True def __init__(self): """Initializer. :rtype: None """ self.provider_type = providers.Provider self.providers = {} self.overridden = tuple() self.parent = None self.declarative_parent = None self.wired_to_modules = [] self.wired_to_packages = [] self.__self__ = providers.Self(self) super(DynamicContainer, self).__init__() def __deepcopy__(self, memo): """Create and return full copy of container.""" copied = memo.get(id(self)) if copied is not None: return copied copied = self.__class__() memo[id(self)] = copied copied.__self__ = providers.deepcopy(self.__self__, memo) for name in copied.__self__.alt_names: copied.set_provider(name, copied.__self__) copied.provider_type = providers.Provider copied.overridden = providers.deepcopy(self.overridden, memo) copied.declarative_parent = self.declarative_parent for name, provider in providers.deepcopy(self.providers, memo).items(): copied.set_provider(name, provider) copied.parent = providers.deepcopy(self.parent, memo) return copied def __setattr__(self, name, value): """Set instance attribute. If value of attribute is provider, it will be added into providers dictionary. :param name: Attribute's name :type name: object :param value: Attribute's value :type value: object :rtype: None """ if isinstance(value, providers.Provider) \ and not isinstance(value, providers.Self) \ and name != 'parent': _check_provider_type(self, value) self.providers[name] = value if isinstance(value, providers.CHILD_PROVIDERS): value.assign_parent(self) super(DynamicContainer, self).__setattr__(name, value) def __delattr__(self, name): """Delete instance attribute. If value of attribute is provider, it will be deleted from providers dictionary. :param name: Attribute's name :type name: object :rtype: None """ if name in self.providers: del self.providers[name] super(DynamicContainer, self).__delattr__(name) @property def dependencies(self): """Return dependency providers dictionary. Dependency providers can be both of :py:class:`dependency_injector.providers.Dependency` and :py:class:`dependency_injector.providers.DependenciesContainer`. :rtype: dict[str, :py:class:`dependency_injector.providers.Provider`] """ return { name: provider for name, provider in self.providers.items() if isinstance(provider, (providers.Dependency, providers.DependenciesContainer)) } def traverse(self, types=None): """Return providers traversal generator.""" yield from providers.traverse(*self.providers.values(), types=types) def set_providers(self, **providers): """Set container providers. :param providers: Dictionary of providers :type providers: dict[object, :py:class:`dependency_injector.providers.Provider`] :rtype: None """ for name, provider in six.iteritems(providers): setattr(self, name, provider) def set_provider(self, name, provider): """Set container provider. :param name: Provider name :type name: str :param provider: Provider :type provider: :py:class:`dependency_injector.providers.Provider` :rtype: None """ setattr(self, name, provider) def override(self, object overriding): """Override current container by overriding container. :param overriding: Overriding container. :type overriding: :py:class:`DynamicContainer` :raise: :py:exc:`dependency_injector.errors.Error` if trying to override container by itself :rtype: None """ if overriding is self: raise errors.Error('Container {0} could not be overridden ' 'with itself'.format(self)) self.overridden += (overriding,) for name, provider in six.iteritems(overriding.providers): try: getattr(self, name).override(provider) except AttributeError: pass def override_providers(self, **overriding_providers): """Override container providers. :param overriding_providers: Dictionary of providers :type overriding_providers: dict[str, :py:class:`dependency_injector.providers.Provider`] :rtype: None """ for name, overriding_provider in six.iteritems(overriding_providers): container_provider = getattr(self, name) container_provider.override(overriding_provider) def reset_last_overriding(self): """Reset last overriding provider for each container providers. :rtype: None """ if not self.overridden: raise errors.Error('Container {0} is not overridden'.format(self)) self.overridden = self.overridden[:-1] for provider in six.itervalues(self.providers): provider.reset_last_overriding() def reset_override(self): """Reset all overridings for each container providers. :rtype: None """ self.overridden = tuple() for provider in six.itervalues(self.providers): provider.reset_override() def wire(self, modules=None, packages=None): """Wire container providers with provided packages and modules. :rtype: None """ wire( container=self, modules=modules, packages=packages, ) if modules: self.wired_to_modules.extend(modules) if packages: self.wired_to_packages.extend(packages) def unwire(self): """Unwire container providers from previously wired packages and modules.""" unwire( modules=self.wired_to_modules, packages=self.wired_to_packages, ) self.wired_to_modules.clear() self.wired_to_packages.clear() def init_resources(self): """Initialize all container resources.""" futures = [] for provider in self.traverse(types=[providers.Resource]): resource = provider.init() if __is_future_or_coroutine(resource): futures.append(resource) if futures: return asyncio.gather(*futures) def shutdown_resources(self): """Shutdown all container resources.""" def _independent_resources(resources): for resource in resources: for other_resource in resources: if not other_resource.initialized: continue if resource in other_resource.related: break else: yield resource async def _async_ordered_shutdown(resources): while any(resource.initialized for resource in resources): resources_to_shutdown = list(_independent_resources(resources)) if not resources_to_shutdown: raise RuntimeError('Unable to resolve resources shutdown order') futures = [] for resource in resources_to_shutdown: result = resource.shutdown() if __is_future_or_coroutine(result): futures.append(result) await asyncio.gather(*futures) def _sync_ordered_shutdown(resources): while any(resource.initialized for resource in resources): resources_to_shutdown = list(_independent_resources(resources)) if not resources_to_shutdown: raise RuntimeError('Unable to resolve resources shutdown order') for resource in resources_to_shutdown: resource.shutdown() resources = list(self.traverse(types=[providers.Resource])) if any(resource.is_async_mode_enabled() for resource in resources): return _async_ordered_shutdown(resources) else: return _sync_ordered_shutdown(resources) def apply_container_providers_overridings(self): """Apply container providers' overridings.""" for provider in self.traverse(types=[providers.Container]): provider.apply_overridings() def reset_singletons(self): """Reset container singletons.""" for provider in self.traverse(types=[providers.BaseSingleton]): provider.reset() return SingletonResetContext(self) def check_dependencies(self): """Check if container dependencies are defined. If any dependency is undefined, raises an error. """ undefined = [ dependency for dependency in self.traverse(types=[providers.Dependency]) if not dependency.is_defined ] if not undefined: return container_name = self.parent_name if self.parent_name else self.__class__.__name__ undefined_names = [ f'"{dependency.parent_name if dependency.parent_name else dependency}"' for dependency in undefined ] raise errors.Error( f'Container "{container_name}" has undefined dependencies: ' f'{", ".join(undefined_names)}', ) def from_schema(self, schema): """Build container providers from schema.""" from .schema import build_schema for name, provider in build_schema(schema).items(): self.set_provider(name, provider) def from_yaml_schema(self, filepath, loader=None): """Build container providers from YAML schema. You can specify type of loader as a second argument. By default, method uses ``SafeLoader``. """ if yaml is None: raise errors.Error( 'Unable to load yaml schema - PyYAML is not installed. ' 'Install PyYAML or install Dependency Injector with yaml extras: ' '"pip install dependency-injector[yaml]"' ) if loader is None: loader = yaml.SafeLoader with open(filepath) as file: schema = yaml.load(file, loader) self.from_schema(schema) def from_json_schema(self, filepath): """Build container providers from JSON schema.""" with open(filepath) as file: schema = json.load(file) self.from_schema(schema) def resolve_provider_name(self, provider): """Try to resolve provider name.""" for provider_name, container_provider in self.providers.items(): if container_provider is provider: return provider_name else: raise errors.Error(f'Can not resolve name for provider "{provider}"') @property def parent_name(self): """Return parent name.""" if self.parent: return self.parent.parent_name if self.declarative_parent: return self.declarative_parent.__name__ return None def assign_parent(self, parent): """Assign parent.""" self.parent = parent class DeclarativeContainerMetaClass(type): """Declarative inversion of control container meta class.""" def __new__(type mcs, str class_name, tuple bases, dict attributes): """Declarative container class factory.""" self = mcs.__fetch_self(attributes) if self is None: self = providers.Self() containers = { name: container for name, container in six.iteritems(attributes) if is_container(container) } cls_providers = { name: provider for name, provider in six.iteritems(attributes) if isinstance(provider, providers.Provider) and not isinstance(provider, providers.Self) } inherited_providers = { name: provider for base in bases if is_container(base) and base is not DynamicContainer for name, provider in six.iteritems(base.providers) } all_providers = {} all_providers.update(inherited_providers) all_providers.update(cls_providers) attributes['containers'] = containers attributes['inherited_providers'] = inherited_providers attributes['cls_providers'] = cls_providers attributes['providers'] = all_providers cls = type.__new__(mcs, class_name, bases, attributes) self.set_container(cls) cls.__self__ = self for provider in six.itervalues(cls.providers): _check_provider_type(cls, provider) for provider in six.itervalues(cls.cls_providers): if isinstance(provider, providers.CHILD_PROVIDERS): provider.assign_parent(cls) return cls def __setattr__(cls, str name, object value): """Set class attribute. If value of attribute is provider, it will be added into providers dictionary. :param name: Attribute's name :type name: str :param value: Attribute's value :type value: object :rtype: None """ if isinstance(value, providers.Provider) and name != '__self__': _check_provider_type(cls, value) if isinstance(value, providers.CHILD_PROVIDERS): value.assign_parent(cls) cls.providers[name] = value cls.cls_providers[name] = value super(DeclarativeContainerMetaClass, cls).__setattr__(name, value) def __delattr__(cls, str name): """Delete class attribute. If value of attribute is provider, it will be deleted from providers dictionary. :param name: Attribute's name :type name: str :rtype: None """ if name in cls.providers and name in cls.cls_providers: del cls.providers[name] del cls.cls_providers[name] super(DeclarativeContainerMetaClass, cls).__delattr__(name) @property def dependencies(cls): """Return dependency providers dictionary. Dependency providers can be both of :py:class:`dependency_injector.providers.Dependency` and :py:class:`dependency_injector.providers.DependenciesContainer`. :rtype: dict[str, :py:class:`dependency_injector.providers.Provider`] """ return { name: provider for name, provider in cls.providers.items() if isinstance(provider, (providers.Dependency, providers.DependenciesContainer)) } def traverse(cls, types=None): """Return providers traversal generator.""" yield from providers.traverse(*cls.providers.values(), types=types) def resolve_provider_name(cls, provider): """Try to resolve provider name.""" for provider_name, container_provider in cls.providers.items(): if container_provider is provider: return provider_name else: raise errors.Error(f'Can not resolve name for provider "{provider}"') @property def parent_name(cls): """Return parent name.""" return cls.__name__ @staticmethod def __fetch_self(attributes): self = None alt_names = [] for name, value in attributes.items(): if not isinstance(value, providers.Self): continue if self is not None and value is not self: raise errors.Error('Container can have only one "Self" provider') if name != '__self__': alt_names.append(name) self = value if self: self.set_alt_names(alt_names) return self @six.add_metaclass(DeclarativeContainerMetaClass) class DeclarativeContainer(Container): """Declarative inversion of control container. .. code-block:: python class Services(DeclarativeContainer): auth = providers.Factory(AuthService) users = providers.Factory(UsersService, auth_service=auth) """ __IS_CONTAINER__ = True provider_type = providers.Provider """Type of providers that could be placed in container. :type: type """ instance_type = DynamicContainer """Type of container that is returned on instantiating declarative container. :type: type """ containers = dict() """Read-only dictionary of all nested containers. :type: dict[str, :py:class:`DeclarativeContainer`] """ providers = dict() """Read-only dictionary of all providers. :type: dict[str, :py:class:`dependency_injector.providers.Provider`] """ cls_providers = dict() """Read-only dictionary of current container providers. :type: dict[str, :py:class:`dependency_injector.providers.Provider`] """ inherited_providers = dict() """Read-only dictionary of inherited providers. :type: dict[str, :py:class:`dependency_injector.providers.Provider`] """ overridden = tuple() """Tuple of overriding containers. :type: tuple[:py:class:`DeclarativeContainer`] """ __self__ = None """Provider that provides current container. :type: :py:class:`dependency_injector.providers.Provider` """ def __new__(cls, **overriding_providers): """Constructor. :return: Dynamic container with copy of all providers. :rtype: :py:class:`DynamicContainer` """ container = cls.instance_type() container.provider_type = cls.provider_type container.declarative_parent = cls copied_providers = providers.deepcopy({ **cls.providers, **{'@@self@@': cls.__self__}}) copied_self = copied_providers.pop('@@self@@') copied_self.set_container(container) container.__self__ = copied_self for name in copied_self.alt_names: container.set_provider(name, copied_self) for name, provider in copied_providers.items(): container.set_provider(name, provider) container.override_providers(**overriding_providers) container.apply_container_providers_overridings() return container @classmethod def override(cls, object overriding): """Override current container by overriding container. :param overriding: Overriding container. :type overriding: :py:class:`DeclarativeContainer` :raise: :py:exc:`dependency_injector.errors.Error` if trying to override container by itself or its subclasses :rtype: None """ if issubclass(cls, overriding): raise errors.Error('Container {0} could not be overridden ' 'with itself or its subclasses'.format(cls)) cls.overridden += (overriding,) for name, provider in six.iteritems(overriding.cls_providers): try: getattr(cls, name).override(provider) except AttributeError: pass @classmethod def reset_last_overriding(cls): """Reset last overriding provider for each container providers. :rtype: None """ if not cls.overridden: raise errors.Error('Container {0} is not overridden'.format(cls)) cls.overridden = cls.overridden[:-1] for provider in six.itervalues(cls.providers): provider.reset_last_overriding() @classmethod def reset_override(cls): """Reset all overridings for each container providers. :rtype: None """ cls.overridden = tuple() for provider in six.itervalues(cls.providers): provider.reset_override() class SingletonResetContext: def __init__(self, container): self._container = container def __enter__(self): return self._container def __exit__(self, *_): self._container.reset_singletons() def override(object container): """:py:class:`DeclarativeContainer` overriding decorator. :param container: Container that should be overridden by decorated container. :type container: :py:class:`DeclarativeContainer` :return: Declarative container's overriding decorator. :rtype: callable(:py:class:`DeclarativeContainer`) """ def _decorator(object overriding_container): """Overriding decorator.""" container.override(overriding_container) return overriding_container return _decorator def copy(object container): """:py:class:`DeclarativeContainer` copying decorator. This decorator copies all providers from provided container to decorated one. If one of the decorated container providers matches to source container providers by name, it would be replaced by reference. :param container: Container that should be copied by decorated container. :type container: :py:class:`DeclarativeContainer` :return: Declarative container's copying decorator. :rtype: callable(:py:class:`DeclarativeContainer`) """ def _get_providers_memo(from_providers, source_providers): memo = dict() for name, provider in from_providers.items(): try: source_provider = source_providers[name] except KeyError: continue else: memo[id(source_provider)] = provider if hasattr(provider, 'providers') and hasattr(source_provider, 'providers'): sub_memo = _get_providers_memo(provider.providers, source_provider.providers) memo.update(sub_memo) return memo def _decorator(copied_container): memo = _get_providers_memo(copied_container.cls_providers, container.providers) providers_copy = providers.deepcopy(container.providers, memo) for name, provider in six.iteritems(providers_copy): setattr(copied_container, name, provider) return copied_container return _decorator cpdef bint is_container(object instance): """Check if instance is container instance. :param instance: Instance to be checked. :type instance: object :rtype: bool """ return getattr(instance, '__IS_CONTAINER__', False) is True cpdef object _check_provider_type(object container, object provider): if not isinstance(provider, container.provider_type): raise errors.Error('{0} can contain only {1} ' 'instances'.format(container, container.provider_type))