shim _resource_extend for neutron-lib

The resource_extend module was rehomed into neutron-lib with commit
This patch shims neutron.db._resource_extend to reference neutron-lib's
implementation allowing consumers to switch over with worrying about
dependency chains. Once all consumers switch over a follow-up patch
will be submitted to remove neutron's _resource_extend module.


Change-Id: I9ffe91b6dedaf46d679c6a3c4f465f2bfd66e32d
Boden R 4 years ago
parent 462b510c50
commit 176ce5ce30

@ -15,124 +15,13 @@ NOTE: This module shall not be used by external projects. It will be moved
to neutron-lib in due course, and then it can be used from there.
import collections
import inspect
from neutron_lib.db import resource_extend
from neutron_lib.utils import helpers
# This dictionary will store methods for extending API resources.
# Extensions can add their own methods by invoking register_funcs().
_resource_extend_functions = {
# <resource1> : [<func1>, <func2>, ...],
# <resource2> : [<func1>, <func2>, ...],
# ...
# This dictionary will store @extends decorated methods with a list of
# resources that each method will extend on class initialization.
_DECORATED_EXTEND_METHODS = collections.defaultdict(list)
def register_funcs(resource, funcs):
"""Add functions to extend a resource.
:param resource: A resource collection name.
:type resource: str
:param funcs: A list of functions.
:type funcs: list of callable
These functions take a resource dict and a resource object and
update the resource dict with extension data (possibly retrieved
from the resource db object).
def _extend_foo_with_bar(foo_res, foo_db):
foo_res['bar'] = foo_db.bar_info # example
return foo_res
funcs = [helpers.make_weak_ref(f) if callable(f) else f
for f in funcs]
_resource_extend_functions.setdefault(resource, []).extend(funcs)
def get_funcs(resource):
"""Retrieve a list of functions extending a resource.
:param resource: A resource collection name.
:type resource: str
:return: A list (possibly empty) of functions extending resource.
:rtype: list of callable
return _resource_extend_functions.get(resource, [])
def apply_funcs(resource_type, response, db_object):
for func in get_funcs(resource_type):
resolved_func = helpers.resolve_ref(func)
if resolved_func:
resolved_func(response, db_object)
def extends(resources):
"""Use to decorate methods on classes before initialization.
Any classes that use this must themselves be decorated with the
@has_resource_extenders decorator to setup the __new__ method to
actually register the instance methods after initialization.
:param resources: Resource collection names. The decorated method will
be registered with each resource as an extend function.
:type resources: list of str
def decorator(method):
return method
return decorator
def has_resource_extenders(klass):
"""Decorator to setup __new__ method in classes to extend resources.
Any method decorated with @extends above is an unbound method on a class.
This decorator sets up the class __new__ method to add the bound
method to _resource_extend_functions after object instantiation.
orig_new = klass.__new__
new_inherited = '__new__' not in klass.__dict__
def replacement_new(cls, *args, **kwargs):
if new_inherited:
# class didn't define __new__ so we need to call inherited __new__
super_new = super(klass, cls).__new__
if super_new is object.__new__:
# object.__new__ doesn't accept args nor kwargs
instance = super_new(cls)
instance = super_new(cls, *args, **kwargs)
instance = orig_new(cls, *args, **kwargs)
if getattr(instance, '_DECORATED_METHODS_REGISTERED', False):
# Avoid running this logic twice for classes inheriting other
# classes with this same decorator. Only one needs to execute
# to subscribe all decorated methods.
return instance
for name, unbound_method in inspect.getmembers(cls):
if (not inspect.ismethod(unbound_method) and
not inspect.isfunction(unbound_method)):
# Handle py27/py34 difference
method = getattr(unbound_method, 'im_func', unbound_method)
for resource in _DECORATED_EXTEND_METHODS[method]:
# Register the bound method for the resourse
register_funcs(resource, [method])
setattr(instance, '_DECORATED_METHODS_REGISTERED', True)
return instance
klass.__new__ = replacement_new
return klass
_resource_extend_functions = resource_extend._resource_extend_functions
register_funcs = resource_extend.register_funcs
get_funcs = resource_extend.get_funcs
apply_funcs = resource_extend.apply_funcs
extends = resource_extend.extends
has_resource_extenders = resource_extend.has_resource_extenders

@ -46,7 +46,6 @@ from neutron.api.rpc.callbacks.consumer import registry as rpc_consumer_reg
from neutron.api.rpc.callbacks.producer import registry as rpc_producer_reg
from neutron.common import config
from neutron.conf.agent import common as agent_config
from neutron.db import _resource_extend as resource_extend
from neutron.db import agentschedulers_db
from neutron import manager
from neutron import policy
@ -205,17 +204,13 @@ class DietTestCase(base.BaseTestCase):
# six before removing the cleanup callback from here.
self.orig_pid = os.getpid()
def reset_resource_extend_functions():
resource_extend._resource_extend_functions = {}
def addOnException(self, handler):
def safe_handler(*args, **kwargs):