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Diffstat (limited to 'indra/viewer_components/updater/scripts/darwin/janitor.py')
| -rw-r--r-- | indra/viewer_components/updater/scripts/darwin/janitor.py | 133 |
1 files changed, 133 insertions, 0 deletions
diff --git a/indra/viewer_components/updater/scripts/darwin/janitor.py b/indra/viewer_components/updater/scripts/darwin/janitor.py new file mode 100644 index 0000000000..cdf33df731 --- /dev/null +++ b/indra/viewer_components/updater/scripts/darwin/janitor.py @@ -0,0 +1,133 @@ +#!/usr/bin/python +"""\ +@file janitor.py +@author Nat Goodspeed +@date 2011-09-14 +@brief Janitor class to clean up arbitrary resources + +2013-01-04 cloned from vita because it's exactly what update_install.py needs. + +$LicenseInfo:firstyear=2011&license=viewerlgpl$ +Copyright (c) 2011, Linden Research, Inc. +$/LicenseInfo$ +""" + +import sys +import functools +import itertools + +class Janitor(object): + """ + Usage: + + Basic: + self.janitor = Janitor(sys.stdout) # report cleanup actions on stdout + ... + self.janitor.later(os.remove, some_temp_file) + self.janitor.later(os.remove, some_other_file) + ... + self.janitor.cleanup() # perform cleanup actions + + Context Manager: + with Janitor() as janitor: # clean up quietly + ... + janitor.later(shutil.rmtree, some_temp_directory) + ... + # exiting 'with' block performs cleanup + + Test Class: + class TestMySoftware(unittest.TestCase, Janitor): + def __init__(self): + Janitor.__init__(self) # quiet cleanup + ... + + def setUp(self): + ... + self.later(os.rename, saved_file, original_location) + ... + + def tearDown(self): + Janitor.tearDown(self) # calls cleanup() + ... + # Or, if you have no other tearDown() logic for + # TestMySoftware, you can omit the TestMySoftware.tearDown() + # def entirely and let it inherit Janitor.tearDown(). + """ + def __init__(self, stream=None): + """ + If you pass stream= (e.g.) sys.stdout or sys.stderr, Janitor will + report its cleanup operations as it performs them. If you don't, it + will perform them quietly -- unless one or more of the actions throws + an exception, in which case you'll get output on stderr. + """ + self.stream = stream + self.cleanups = [] + + def later(self, func, *args, **kwds): + """ + Pass the callable you want to call at cleanup() time, plus any + positional or keyword args you want to pass it. + """ + # Get a name string for 'func' + try: + # A free function has a __name__ + name = func.__name__ + except AttributeError: + try: + # A class object (even builtin objects like ints!) support + # __class__.__name__ + name = func.__class__.__name__ + except AttributeError: + # Shrug! Just use repr() to get a string describing this func. + name = repr(func) + # Construct a description of this operation in Python syntax from + # args, kwds. + desc = "%s(%s)" % \ + (name, ", ".join(itertools.chain((repr(a) for a in args), + ("%s=%r" % (k, v) for (k, v) in kwds.iteritems())))) + # Use functools.partial() to bind passed args and keywords to the + # passed func so we get a nullary callable that does what caller + # wants. + bound = functools.partial(func, *args, **kwds) + self.cleanups.append((desc, bound)) + + def cleanup(self): + """ + Perform all the actions saved with later() calls. + """ + # Typically one allocates resource A, then allocates resource B that + # depends on it. In such a scenario it's appropriate to delete B + # before A -- so perform cleanup actions in reverse order. (This is + # the same strategy used by atexit().) + while self.cleanups: + # Until our list is empty, pop the last pair. + desc, bound = self.cleanups.pop(-1) + + # If requested, report the action. + if self.stream is not None: + print >>self.stream, desc + + try: + # Call the bound callable + bound() + except Exception, err: + # This is cleanup. Report the problem but continue. + print >>(self.stream or sys.stderr), "Calling %s\nraised %s: %s" % \ + (desc, err.__class__.__name__, err) + + def tearDown(self): + """ + If a unittest.TestCase subclass (or a nose test class) adds Janitor as + one of its base classes, and has no other tearDown() logic, let it + inherit Janitor.tearDown(). + """ + self.cleanup() + + def __enter__(self): + return self + + def __exit__(self, type, value, tb): + # Perform cleanup no matter how we exit this 'with' statement + self.cleanup() + # Propagate any exception from the 'with' statement, don't swallow it + return False |