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# -*- test-case-name: twisted.trial.test.test_util -*-
# Copyright (c) 2001-2010 Twisted Matrix Laboratories.
# See LICENSE for details.
#
"""
A collection of utility functions and classes, used internally by Trial.
This code is for Trial's internal use. Do NOT use this code if you are writing
tests. It is subject to change at the Trial maintainer's whim. There is
nothing here in this module for you to use unless you are maintaining Trial.
Any non-Trial Twisted code that uses this module will be shot.
Maintainer: Jonathan Lange
"""
import traceback, sys
from twisted.internet import defer, utils, interfaces
from twisted.python.failure import Failure
from twisted.python import deprecate, versions
DEFAULT_TIMEOUT = object()
DEFAULT_TIMEOUT_DURATION = 120.0
class DirtyReactorAggregateError(Exception):
"""
Passed to L{twisted.trial.itrial.IReporter.addError} when the reactor is
left in an unclean state after a test.
@ivar delayedCalls: The L{DelayedCall} objects which weren't cleaned up.
@ivar selectables: The selectables which weren't cleaned up.
"""
def __init__(self, delayedCalls, selectables=None):
self.delayedCalls = delayedCalls
self.selectables = selectables
def __str__(self):
"""
Return a multi-line message describing all of the unclean state.
"""
msg = "Reactor was unclean."
if self.delayedCalls:
msg += ("\nDelayedCalls: (set "
"twisted.internet.base.DelayedCall.debug = True to "
"debug)\n")
msg += "\n".join(map(str, self.delayedCalls))
if self.selectables:
msg += "\nSelectables:\n"
msg += "\n".join(map(str, self.selectables))
return msg
class _Janitor(object):
"""
The guy that cleans up after you.
@ivar test: The L{TestCase} to report errors about.
@ivar result: The L{IReporter} to report errors to.
@ivar reactor: The reactor to use. If None, the global reactor
will be used.
"""
def __init__(self, test, result, reactor=None):
"""
@param test: See L{_Janitor.test}.
@param result: See L{_Janitor.result}.
@param reactor: See L{_Janitor.reactor}.
"""
self.test = test
self.result = result
self.reactor = reactor
def postCaseCleanup(self):
"""
Called by L{unittest.TestCase} after a test to catch any logged errors
or pending L{DelayedCall}s.
"""
calls = self._cleanPending()
if calls:
aggregate = DirtyReactorAggregateError(calls)
self.result.addError(self.test, Failure(aggregate))
return False
return True
def postClassCleanup(self):
"""
Called by L{unittest.TestCase} after the last test in a C{TestCase}
subclass. Ensures the reactor is clean by murdering the threadpool,
catching any pending L{DelayedCall}s, open sockets etc.
"""
selectables = self._cleanReactor()
calls = self._cleanPending()
if selectables or calls:
aggregate = DirtyReactorAggregateError(calls, selectables)
self.result.addError(self.test, Failure(aggregate))
self._cleanThreads()
def _getReactor(self):
"""
Get either the passed-in reactor or the global reactor.
"""
if self.reactor is not None:
reactor = self.reactor
else:
from twisted.internet import reactor
return reactor
def _cleanPending(self):
"""
Cancel all pending calls and return their string representations.
"""
reactor = self._getReactor()
# flush short-range timers
reactor.iterate(0)
reactor.iterate(0)
delayedCallStrings = []
for p in reactor.getDelayedCalls():
if p.active():
delayedString = str(p)
p.cancel()
else:
print "WEIRDNESS! pending timed call not active!"
delayedCallStrings.append(delayedString)
return delayedCallStrings
_cleanPending = utils.suppressWarnings(
_cleanPending, (('ignore',), {'category': DeprecationWarning,
'message':
r'reactor\.iterate cannot be used.*'}))
def _cleanThreads(self):
reactor = self._getReactor()
if interfaces.IReactorThreads.providedBy(reactor):
if reactor.threadpool is not None:
# Stop the threadpool now so that a new one is created.
# This improves test isolation somewhat (although this is a
# post class cleanup hook, so it's only isolating classes
# from each other, not methods from each other).
reactor._stopThreadPool()
def _cleanReactor(self):
"""
Remove all selectables from the reactor, kill any of them that were
processes, and return their string representation.
"""
reactor = self._getReactor()
selectableStrings = []
for sel in reactor.removeAll():
if interfaces.IProcessTransport.providedBy(sel):
sel.signalProcess('KILL')
selectableStrings.append(repr(sel))
return selectableStrings
def excInfoOrFailureToExcInfo(err):
"""
Coerce a Failure to an _exc_info, if err is a Failure.
@param err: Either a tuple such as returned by L{sys.exc_info} or a
L{Failure} object.
@return: A tuple like the one returned by L{sys.exc_info}. e.g.
C{exception_type, exception_object, traceback_object}.
"""
if isinstance(err, Failure):
# Unwrap the Failure into a exc_info tuple.
err = (err.type, err.value, err.getTracebackObject())
return err
def suppress(action='ignore', **kwarg):
"""
Sets up the .suppress tuple properly, pass options to this method as you
would the stdlib warnings.filterwarnings()
So, to use this with a .suppress magic attribute you would do the
following:
>>> from twisted.trial import unittest, util
>>> import warnings
>>>
>>> class TestFoo(unittest.TestCase):
... def testFooBar(self):
... warnings.warn("i am deprecated", DeprecationWarning)
... testFooBar.suppress = [util.suppress(message='i am deprecated')]
...
>>>
Note that as with the todo and timeout attributes: the module level
attribute acts as a default for the class attribute which acts as a default
for the method attribute. The suppress attribute can be overridden at any
level by specifying C{.suppress = []}
"""
return ((action,), kwarg)
def profiled(f, outputFile):
def _(*args, **kwargs):
if sys.version_info[0:2] != (2, 4):
import profile
prof = profile.Profile()
try:
result = prof.runcall(f, *args, **kwargs)
prof.dump_stats(outputFile)
except SystemExit:
pass
prof.print_stats()
return result
else: # use hotshot, profile is broken in 2.4
import hotshot.stats
prof = hotshot.Profile(outputFile)
try:
return prof.runcall(f, *args, **kwargs)
finally:
stats = hotshot.stats.load(outputFile)
stats.strip_dirs()
stats.sort_stats('cum') # 'time'
stats.print_stats(100)
return _
def getPythonContainers(meth):
"""Walk up the Python tree from method 'meth', finding its class, its module
and all containing packages."""
containers = []
containers.append(meth.im_class)
moduleName = meth.im_class.__module__
while moduleName is not None:
module = sys.modules.get(moduleName, None)
if module is None:
module = __import__(moduleName)
containers.append(module)
moduleName = getattr(module, '__module__', None)
return containers
_DEFAULT = object()
def acquireAttribute(objects, attr, default=_DEFAULT):
"""Go through the list 'objects' sequentially until we find one which has
attribute 'attr', then return the value of that attribute. If not found,
return 'default' if set, otherwise, raise AttributeError. """
for obj in objects:
if hasattr(obj, attr):
return getattr(obj, attr)
if default is not _DEFAULT:
return default
raise AttributeError('attribute %r not found in %r' % (attr, objects))
deprecate.deprecatedModuleAttribute(
versions.Version("Twisted", 10, 1, 0),
"Please use twisted.python.reflect.namedAny instead.",
__name__, "findObject")
def findObject(name):
"""Get a fully-named package, module, module-global object or attribute.
Forked from twisted.python.reflect.namedAny.
Returns a tuple of (bool, obj). If bool is True, the named object exists
and is returned as obj. If bool is False, the named object does not exist
and the value of obj is unspecified.
"""
names = name.split('.')
topLevelPackage = None
moduleNames = names[:]
while not topLevelPackage:
trialname = '.'.join(moduleNames)
if len(trialname) == 0:
return (False, None)
try:
topLevelPackage = __import__(trialname)
except ImportError:
# if the ImportError happened in the module being imported,
# this is a failure that should be handed to our caller.
# count stack frames to tell the difference.
exc_info = sys.exc_info()
if len(traceback.extract_tb(exc_info[2])) > 1:
try:
# Clean up garbage left in sys.modules.
del sys.modules[trialname]
except KeyError:
# Python 2.4 has fixed this. Yay!
pass
raise exc_info[0], exc_info[1], exc_info[2]
moduleNames.pop()
obj = topLevelPackage
for n in names[1:]:
try:
obj = getattr(obj, n)
except AttributeError:
return (False, obj)
return (True, obj)
def _runSequentially(callables, stopOnFirstError=False):
"""
Run the given callables one after the other. If a callable returns a
Deferred, wait until it has finished before running the next callable.
@param callables: An iterable of callables that take no parameters.
@param stopOnFirstError: If True, then stop running callables as soon as
one raises an exception or fires an errback. False by default.
@return: A L{Deferred} that fires a list of C{(flag, value)} tuples. Each
tuple will be either C{(SUCCESS, <return value>)} or C{(FAILURE,
<Failure>)}.
"""
results = []
for f in callables:
d = defer.maybeDeferred(f)
thing = defer.waitForDeferred(d)
yield thing
try:
results.append((defer.SUCCESS, thing.getResult()))
except:
results.append((defer.FAILURE, Failure()))
if stopOnFirstError:
break
yield results
_runSequentially = defer.deferredGenerator(_runSequentially)
__all__ = ['FailureError', 'DirtyReactorWarning', 'DirtyReactorError',
'PendingTimedCallsError', 'excInfoOrFailureToExcInfo']
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