def start(self):
assert not self.active
try:
# Apply the RabbitMQ virtual host patch
self._vhostPatch = RabbitmqVirtualHostPatch(clientLabel=self._clientLabel,
kw=None, logger=self._logger)
self._vhostPatch.start()
# Apply Model Checkpoint Manager patch
self._modelCheckpointPatch = ModelCheckpointStoragePatch(
kw=None, logger=self._logger)
self._modelCheckpointPatch.start()
# Self-validation
actualVhost = (
amqp.connection.getRabbitmqConnectionParameters().vhost)
assert actualVhost == self._vhostPatch._vhost, (
"Expected vhost=%r, but got vhost=%r") % (
self._vhost, actualVhost)
except Exception:
self._logger.exception("patch failed, removing sub-patches")
self._removePatches()
raise
self.active = True
self._logger.info("%s: applied patch", self.__class__.__name__)
class ModelSwapperIsolationPatch(object):
""" An instance of this class may be used as a decorator, class decorator or
Context Manager for redirecting ModelSwapperInterface input, result and
notification endpoints as well as model checkpoints both in-proc and in
subprocesses. Deletes the redirected endpoints and model checkpoints on stop.
"""
def __init__(self, clientLabel, kw=None, logger=logging):
"""
clientLabel: this string will be used to construct the temporary endpoint
names. The following characters are permitted, and it shouldn't be too
long: [._a-zA-Z]. This may be helpful with diagnostics. A specific test
class name (or similar) would make a reasonable clientLabel.
kw: name of keyword argument to add to the decorated function(s). Its value
will be a reference to this instance of ModelSwapperIsolationPatch.
Ignored when this instance is used as context manager. Defaults to kw=None
to avoid having it added to the keyword args.
"""
self.active = False
""" True when applied successfully; False after successfully removed or not
applied """
self._clientLabel = clientLabel
self._kw = kw
self._logger = logger
self._vhostPatch = None
""" RabbitMQ virtual host patch """
self._modelCheckpointPatch = None
""" Model checkpoint storage patch """
def __enter__(self):
self.start()
return self
def __exit__(self, *args):
self.stop()
return False
def __call__(self, f):
""" Implement the function or class decorator """
if isinstance(f, types.TypeType):
return self._decorateClass(f)
@functools.wraps(f)
def applyModelSwapperIsolationPatch(*args, **kwargs):
self.start()
try:
if self._kw is not None:
kwargs[self._kw] = self
return f(*args, **kwargs)
finally:
self.stop()
return applyModelSwapperIsolationPatch
def _decorateClass(self, targetClass):
""" Decorate the test methods in the given class. Honors
`mock.patch.TEST_PREFIX` for choosing which methods to wrap
"""
for attrName in dir(targetClass):
if attrName.startswith(patch.TEST_PREFIX):
f = getattr(targetClass, attrName)
if callable(f):
decoratedFunc = ModelSwapperIsolationPatch(
self._clientLabel, self._kw, self._logger)(f)
setattr(targetClass, attrName, decoratedFunc)
return targetClass
def start(self):
assert not self.active
try:
# Apply the RabbitMQ virtual host patch
self._vhostPatch = RabbitmqVirtualHostPatch(clientLabel=self._clientLabel,
kw=None, logger=self._logger)
self._vhostPatch.start()
# Apply Model Checkpoint Manager patch
self._modelCheckpointPatch = ModelCheckpointStoragePatch(
kw=None, logger=self._logger)
self._modelCheckpointPatch.start()
# Self-validation
actualVhost = (
amqp.connection.getRabbitmqConnectionParameters().vhost)
assert actualVhost == self._vhostPatch._vhost, (
"Expected vhost=%r, but got vhost=%r") % (
self._vhost, actualVhost)
except Exception:
self._logger.exception("patch failed, removing sub-patches")
self._removePatches()
raise
self.active = True
self._logger.info("%s: applied patch", self.__class__.__name__)
def stop(self):
assert self.active
self._removePatches()
self.active = False
def _removePatches(self):
""" NOTE: may be called intenrally to clean-up mid-application of patch
"""
try:
if (self._modelCheckpointPatch is not None
and self._modelCheckpointPatch.active):
self._modelCheckpointPatch.stop()
else:
assert not self.active
finally:
if self._vhostPatch is not None and self._vhostPatch.active:
self._vhostPatch.stop()
else:
assert not self.active
self._logger.info("%s: removed patch", self.__class__.__name__)
