def __call__(self, *args, **kwargs):
node_id = "%s-%s" % (self.trace_name, self.call_number)
r = super(TracingProxy, self).__call__(*args, **kwargs)
assert is_result_proxy(r)
factory = r.__factory__
factory.node_id = node_id
deps = []
deps_ids = set()
for a in args:
if is_result_proxy(a):
if id(a) not in deps_ids:
deps.append(a)
deps_ids.add(id(a))
for k in kwargs.values():
if is_result_proxy(k):
if id(k) not in deps_ids:
deps.append(k)
deps_ids.add(id(k))
errors, placeholders = scan_args(args, kwargs)
if errors:
self.tracer.schedule_activity(node_id, self.trace_name)
self.tracer.flush_scheduled()
error_factory = first(errors).__factory__
self.tracer.error(node_id, str(error_factory.value))
for dep in deps:
self.tracer.add_dependency(dep.__factory__.node_id, node_id)
return r
def check_err_and_placeholders(result, value):
err, placeholders = result
try:
wait(value)
except TaskError:
if err is None:
err = value
else:
err = first(err, value)
except SuspendTask:
placeholders = True
return err, placeholders
def collect_err_and_results(result, value):
err, results = result
if not is_result_proxy(value):
return result
try:
wait(value)
except TaskError:
if err is None:
err = value
else:
err = first(err, value)
except SuspendTask:
pass
else:
if results is None:
results = []
results.append(value)
return err, results
def __call__(self, *args, **kwargs):
"""Consult the execution history for results or schedule a new task.
This is method gets called from the user workflow code.
When calling it, the task it refers to can be in one of the following
states: RUNNING, READY, FAILED, TIMEDOUT or NOTSCHEDULED.
* If the task is RUNNING this returns a Placeholder. The Placeholder
interrupts the workflow execution if its result is accessed by
raising a SuspendTask exception.
* If the task is READY this returns a Result object. Calling the result
method on this object will just return the final value the task
produced.
* If the task is FAILED this returns an Error object. Calling the
result method on this object will raise a TaskError exception
containing the error message set by the task.
* In case of a TIMEOUT this returns an Timeout object. Calling the
result method on this object will raise TaskTimedout exception, a
subclass of TaskError.
* If the task was NOTSCHEDULED yet:
* If any errors in arguments, propagate the error by returning
another error.
* If any placeholders in arguments, don't do anything because there
are unresolved dependencies.
* Finally, if all the arguments look OK, schedule it for execution.
"""
task_exec_history = self.task_exec_history
call_number = self.call_number
self.call_number += 1
r = placeholder()
for retry_number, delay in enumerate(self.retry):
if task_exec_history.is_timeout(call_number, retry_number):
continue
if task_exec_history.is_running(call_number, retry_number):
break # result = Placehloder
if task_exec_history.has_result(call_number, retry_number):
value = task_exec_history.result(call_number, retry_number)
order = task_exec_history.order(call_number, retry_number)
try:
value = self.deserialize_result(value)
except Exception as e:
logger.exception('Error while deserializing the activity result:')
self.task_decision.fail(e)
break # result = Placeholder
r = result(value, order)
break
if task_exec_history.is_error(call_number, retry_number):
err = task_exec_history.error(call_number, retry_number)
order = task_exec_history.order(call_number, retry_number)
r = error(err, order)
break
errors, placeholders = scan_args(args, kwargs)
if errors:
r = copy_result_proxy(first(errors))
break
if placeholders:
break # result = Placeholder
try:
input_data = self.serialize_input(*args, **kwargs)
except Exception as e:
logger.exception('Error while serializing the task input:')
self.task_decision.fail(e)
break # result = Placeholder
self.task_decision.schedule(call_number, retry_number, delay, input_data)
break # result = Placeholder
else:
# No retries left, it must be a timeout
order = task_exec_history.order(call_number, retry_number)
r = timeout(order)
return r