odoo/openerp/tools/func.py

115 lines
3.5 KiB
Python

# -*- coding: utf-8 -*-
##############################################################################
#
# OpenERP, Open Source Management Solution
# Copyright (C) 2004-2009 Tiny SPRL (<http://tiny.be>).
# Copyright (C) 2010, 2014 OpenERP s.a. (<http://openerp.com>).
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as
# published by the Free Software Foundation, either version 3 of the
# License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU Affero General Public License for more details.
#
# You should have received a copy of the GNU Affero General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
#
##############################################################################
__all__ = ['synchronized', 'lazy_property', 'classproperty']
from functools import wraps
from inspect import getsourcefile
class lazy_property(object):
""" Decorator for a lazy property of an object, i.e., an object attribute
that is determined by the result of a method call evaluated once. To
reevaluate the property, simply delete the attribute on the object, and
get it again.
"""
def __init__(self, fget):
self.fget = fget
def __get__(self, obj, cls):
if obj is None:
return self
value = self.fget(obj)
setattr(obj, self.fget.__name__, value)
return value
@property
def __doc__(self):
return self.fget.__doc__
@staticmethod
def reset_all(obj):
""" Reset all lazy properties on the instance `obj`. """
cls = type(obj)
obj_dict = vars(obj)
for name in obj_dict.keys():
if isinstance(getattr(cls, name, None), lazy_property):
obj_dict.pop(name)
def synchronized(lock_attr='_lock'):
def decorator(func):
@wraps(func)
def wrapper(self, *args, **kwargs):
lock = getattr(self, lock_attr)
try:
lock.acquire()
return func(self, *args, **kwargs)
finally:
lock.release()
return wrapper
return decorator
def frame_codeinfo(fframe, back=0):
""" Return a (filename, line) pair for a previous frame .
@return (filename, lineno) where lineno is either int or string==''
"""
try:
if not fframe:
return "<unknown>", ''
for i in range(back):
fframe = fframe.f_back
try:
fname = getsourcefile(fframe)
except TypeError:
fname = '<builtin>'
lineno = fframe.f_lineno or ''
return fname, lineno
except Exception:
return "<unknown>", ''
def compose(a, b):
""" Composes the callables ``a`` and ``b``. ``compose(a, b)(*args)`` is
equivalent to ``a(b(*args))``.
Can be used as a decorator by partially applying ``a``::
@partial(compose, a)
def b():
...
"""
@wraps(b)
def wrapper(*args, **kwargs):
return a(b(*args, **kwargs))
return wrapper
class _ClassProperty(property):
def __get__(self, cls, owner):
return self.fget.__get__(None, owner)()
def classproperty(func):
return _ClassProperty(classmethod(func))
# vim:expandtab:smartindent:tabstop=4:softtabstop=4:shiftwidth=4: