kkjot88
commented
1 year ago Here is your example fixed to at least run, results are not what u want thou:
from dependency_injector import containers, providers
from dependency_injector.wiring import inject, Provide, Closing
class MyResource:
init_counter: int = 0
shutdown_counter: int = 0
@classmethod
def reset_counter(cls):
cls.init_counter = 0
cls.shutdown_counter = 0
@classmethod
def init(cls):
cls.init_counter += 1
@classmethod
def shutdown(cls):
cls.shutdown_counter += 1
class FactoryService:
def __init__(self, resource: MyResource):
self.resource = resource
class NestedService:
def __init__(self, factory: FactoryService):
self.factory = factory
def init_resource():
resource = MyResource()
resource.init()
yield resource
resource.shutdown()
class Container(containers.DeclarativeContainer):
resource = providers.Resource(init_resource)
factory_service = providers.Factory(FactoryService, resource)
nested_service = providers.Factory(NestedService, factory_service)
@inject
def test_function(resource: MyResource = Closing[Provide["resource"]]):
return resource
@inject
def test_function_dependency(
# no "Closing" since Container.factory_service itself is not a providers.Resource
factory: FactoryService = Provide["factory_service"],
):
return factory
@inject
def test_nested_dependency(
# no "Closing" since Container.nested_service itself is not a providers.Resource
nested: NestedService = Provide["nested_service"],
):
return nested.factory
if __name__ == "__main__":
container = Container()
container.wire(modules=[__name__])
MyResource.reset_counter()
for _ in range(3):
result = test_nested_dependency()
print(f"Initialized {result.resource.init_counter} times")
print(f"Shut down {result.resource.shutdown_counter} times")<__main__.NestedService object at 0x7fa7838c15d0> <generator object at 0x7fa783a75d00>
Initialized 1 times
Shut down 0 times
<__main__.NestedService object at 0x7fa7838c14b0> <generator object at 0x7fa783a75d00>
Initialized 1 times
Shut down 0 times
<__main__.NestedService object at 0x7fa7838c14b0> <generator object at 0x7fa783a75d00>
Initialized 1 times
Shut down 0 times
Process finished with exit code 0This is because Closing is a wiring thing and it only works when stuff is injected. "Initialized 1 times" is printed 3 times because all the resource declared in the container are initialized once upon container instantiation (or when "container.init_resources()" is called directly) and will only be closed if u call "container.shutdown_resources()", which is not done at all in this example.
To achieve what u want this is what u could do, i would be cautious thou since "Closing" is kind of bugged - https://github.com/ets-labs/python-dependency-injector/issues/699
from dependency_injector import containers, providers
from dependency_injector.wiring import inject, Provide, Closing
class MyResource:
init_counter: int = 0
shutdown_counter: int = 0
@classmethod
def reset_counter(cls):
cls.init_counter = 0
cls.shutdown_counter = 0
@classmethod
def init(cls):
cls.init_counter += 1
@classmethod
def shutdown(cls):
cls.shutdown_counter += 1
class FactoryService:
@inject
def __init__(self, resource: MyResource = Closing[Provide["resource"]]):
self.resource = resource
class NestedService:
def __init__(self, factory: FactoryService):
self.factory = factory
def init_resource():
resource = MyResource()
resource.init()
yield resource
resource.shutdown()
class Container(containers.DeclarativeContainer):
resource = providers.Resource(init_resource)
# We don't pass resource here because it has to injected to take advantage
# of the "Closing" marker.
factory_service = providers.Factory(FactoryService)
nested_service = providers.Factory(NestedService, factory_service)
@inject
def test_function(resource: MyResource = Closing[Provide["resource"]]):
return resource
@inject
def test_function_dependency(
# no "Closing" since Container.factory_service itself is not a providers.Resource
factory: FactoryService = Provide["factory_service"],
):
return factory
@inject
def test_nested_dependency(
# no "Closing" since Container.nested_service itself is not a providers.Resource
nested: NestedService = Provide["nested_service"],
):
return nested.factory
if __name__ == "__main__":
container = Container()
container.wire(modules=[__name__])
container.init_resources()
container.shutdown_resources()
MyResource.reset_counter()
for _ in range(3):
result = test_nested_dependency()
print(f"Initialized {result.resource.init_counter} times")
print(f"Shut down {result.resource.shutdown_counter} times")
<__main__.MyResource object at 0x7fa26cf48d00> <generator object at 0x7fa26de6b420>
<__main__.NestedService object at 0x7fa26cf48d30> <generator object at 0x7fa26de6b420>
Initialized 1 times
Shut down 1 times
<__main__.MyResource object at 0x7fa26cf48d60> <generator object at 0x7fa26de6b420>
<__main__.NestedService object at 0x7fa26cf48dc0> <generator object at 0x7fa26de6b420>
Initialized 2 times
Shut down 2 times
<__main__.MyResource object at 0x7fa26cf48cd0> <generator object at 0x7fa26de6b420>
<__main__.NestedService object at 0x7fa26cf48dc0> <generator object at 0x7fa26de6b420>
Initialized 3 times
Shut down 3 times
Process finished with exit code 0
jazzthief
ssbbkn
Closingdoesn't seem to resolve nested dependecies: e.g. when aFactorydepends on anotherFactorydependent on aResource. I have followed issue #633, and linked PR #636 that dealt with the detection of dependent resources, however in my example it doesn't look like it is working when the dependencies are nested.The following example replicates the code from
dependecy-injectortest suite used to test the dependent resources resolution in PR #636. Apart from different naming, the only things I added areNestedServiceandtest_nested_dependency():Running this with
python 3.11.1anddependency-injector 4.41.0fails for me with the following traceback:Could anyone please provide any guidance as to whether this is expected behaviour or any existing workarounds? I am trying to use
dependency-injectorin a large FastAPI project which would greatly benefit from nestedResourceclosing - and would be glad to try and fix this if possible.