Limnoria/src/utils/python.py

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###
# Copyright (c) 2005, Jeremiah Fincher
# Copyright (c) 2009, James Vega
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are met:
#
# * Redistributions of source code must retain the above copyright notice,
# this list of conditions, and the following disclaimer.
# * Redistributions in binary form must reproduce the above copyright notice,
# this list of conditions, and the following disclaimer in the
# documentation and/or other materials provided with the distribution.
# * Neither the name of the author of this software nor the name of
# contributors to this software may be used to endorse or promote products
# derived from this software without specific prior written consent.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
# ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
# LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
# CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
# SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
# CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
# POSSIBILITY OF SUCH DAMAGE.
###
import sys
import types
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import threading
def universalImport(*names):
"""Attempt to import the given modules, in order, returning the first
successfully imported module. ImportError will be raised, as usual, if
no imports succeed. To emulate ``from ModuleA import ModuleB'', pass the
string 'ModuleA.ModuleB'"""
f = sys._getframe(1)
for name in names:
try:
# __import__ didn't gain keyword arguments until 2.5
ret = __import__(name, f.f_globals)
except ImportError:
continue
else:
if '.' in name:
parts = name.split('.')[1:]
while parts:
ret = getattr(ret, parts[0])
del parts[0]
return ret
raise ImportError, ','.join(names)
def changeFunctionName(f, name, doc=None):
if doc is None:
doc = f.__doc__
newf = types.FunctionType(f.func_code, f.func_globals, name,
f.func_defaults, f.func_closure)
newf.__doc__ = doc
return newf
class Object(object):
def __ne__(self, other):
return not self == other
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class Synchronized(type):
METHODS = '__synchronized__'
LOCK = '_Synchronized_rlock'
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def __new__(cls, name, bases, dict):
sync = set()
for base in bases:
if hasattr(base, Synchronized.METHODS):
sync.update(getattr(base, Synchronized.METHODS))
if Synchronized.METHODS in dict:
sync.update(dict[Synchronized.METHODS])
if sync:
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def synchronized(f):
def g(self, *args, **kwargs):
lock = getattr(self, Synchronized.LOCK)
lock.acquire()
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try:
f(self, *args, **kwargs)
finally:
lock.release()
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return changeFunctionName(g, f.func_name, f.__doc__)
for attr in sync:
if attr in dict:
dict[attr] = synchronized(dict[attr])
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original__init__ = dict.get('__init__')
def __init__(self, *args, **kwargs):
if not hasattr(self, Synchronized.LOCK):
setattr(self, Synchronized.LOCK, threading.RLock())
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if original__init__:
original__init__(self, *args, **kwargs)
else:
# newclass is defined below.
super(newclass, self).__init__(*args, **kwargs)
dict['__init__'] = __init__
newclass = super(Synchronized, cls).__new__(cls, name, bases, dict)
return newclass
# vim:set shiftwidth=4 softtabstop=8 expandtab textwidth=78: