def __call__(self):
assert self._nr_instance != None
transaction = newrelic.api.transaction.current_transaction()
# If there is an active transaction then deferred is being
# called within a context of another deferred so simply call the
# callback and return.
if transaction:
return self._nr_next_object()
# If there is no transaction recorded against the deferred then
# don't need to do anything and can simply call the callback and
# return.
if not hasattr(self._nr_instance, '_nr_transaction'):
return self._nr_next_object()
transaction = self._nr_instance._nr_transaction
# If we can't find a Twisted.Web request object associated with
# the transaction or it is no longer valid then simply call the
# callback and return.
if not hasattr(transaction, '_nr_current_request'):
return self._nr_next_object()
request = transaction._nr_current_request()
if not request:
return self._nr_next_object()
try:
# Save the transaction recorded against the deferred as the
# active transaction.
transaction._save_transaction(transaction)
# Record that are calling a deferred. This changes what we
# do if the request finish() method is being called.
request._nr_is_deferred_callback = True
# We should always be calling into a deferred when we are
# in the wait state for the request. We need to exit that
# wait state.
if request._nr_wait_function_trace:
request._nr_wait_function_trace.__exit__(None, None, None)
request._nr_wait_function_trace = None
else:
_logger.debug('Called a Twisted.Web deferred when we were '
'not in a wait state.')
# Call the deferred and capture any errors that may come
# back from it.
with newrelic.api.error_trace.ErrorTrace(transaction):
with newrelic.api.function_trace.FunctionTrace(
transaction, name='Deferred/Call',
group='Python/Twisted'):
return self._nr_next_object()
finally:
# If the request finish() method was called from the
# deferred then we need to exit the transaction. Other wise
# we need to create a new function trace node for a new wait
# state and pop the transaction.
if request._nr_is_request_finished:
transaction.__exit__(None, None, None)
self._nr_instance._nr_transaction = None
else:
# XXX Should we be removing the transaction from the
# deferred object as well. Can the same deferred be
# called multiple times for same request. It probably
# can be reregistered.
request._nr_wait_function_trace = \
newrelic.api.function_trace.FunctionTrace(
transaction, name='Deferred/Wait',
group='Python/Twisted')
request._nr_wait_function_trace.__enter__()
transaction._drop_transaction(transaction)
request._nr_is_deferred_callback = False
def __call__(self):
assert self._nr_instance != None
transaction = newrelic.api.transaction.current_transaction()
# Check to see if we are being called within the context of any
# sort of transaction. If we are, then we don't bother doing
# anything and just call the wrapped function. This should not
# really ever occur with Twisted.Web wrapper but check anyway.
if transaction:
return self._nr_next_object()
# Always use the default application specified in the agent
# configuration.
application = newrelic.api.application.application_instance()
# We need to fake up a WSGI like environ dictionary with the key
# bits of information we need.
environ = {}
environ['REQUEST_URI'] = self._nr_instance.path
# Now start recording the actual web transaction.
transaction = newrelic.api.web_transaction.WebTransaction(
application, environ)
if not transaction.enabled:
return self._nr_next_object()
transaction.__enter__()
self._nr_instance._nr_transaction = transaction
self._nr_instance._nr_is_deferred_callback = False
self._nr_instance._nr_is_request_finished = False
self._nr_instance._nr_wait_function_trace = None
# We need to add a reference to the Twisted.Web request object
# in the transaction as only able to stash the transaction in a
# deferred. Need to use a weakref to avoid an object cycle which
# may prevent cleanup of transaction.
transaction._nr_current_request = weakref.ref(self._nr_instance)
try:
# Call the original method in a trace object to give better
# context in transaction traces. Three things can happen
# within this call. The render() function which is in turn
# called can return a result immediately which means user
# code should have called finish() on the request, it can
# raise an exception which is caught in process() function
# where error handling calls finish(), or it can return that
# it is not done yet and register deferred callbacks to
# complete the request.
with newrelic.api.function_trace.FunctionTrace(transaction,
name='Request/Process', group='Python/Twisted'):
result = self._nr_next_object()
# In the case of a result having being returned or an
# exception occuring, then finish() will have been called.
# We can't just exit the transaction in the finish call
# however as need to still pop back up through the above
# function trace. So if flagged that have finished, then we
# exit the transaction here. Otherwise we setup a function
# trace to track wait time for deferred and manually pop the
# transaction as being the current one for this thread.
if self._nr_instance._nr_is_request_finished:
transaction.__exit__(None, None, None)
self._nr_instance._nr_transaction = None
self._nr_instance = None
else:
self._nr_instance._nr_wait_function_trace = \
newrelic.api.function_trace.FunctionTrace(
transaction, name='Deferred/Wait',
group='Python/Twisted')
self._nr_instance._nr_wait_function_trace.__enter__()
transaction._drop_transaction(transaction)
except:
# If an error occurs assume that transaction should be
# exited. Technically don't believe this should ever occur
# unless our code here has an error or Twisted.Web is
# broken.
_logger.exception('Unexpected exception raised by Twisted.Web '
'Request.process() exception.')
transaction.__exit__(*sys.exc_info())
self._nr_instance._nr_transaction = None
self._nr_instance = None
raise
return result
