gajim-plural/gajim/plugins/helpers.py

135 lines
3.9 KiB
Python

# This file is part of Gajim.
#
# Gajim is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published
# by the Free Software Foundation; version 3 only.
#
# Gajim 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 General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with Gajim. If not, see <http://www.gnu.org/licenses/>.
'''
Helper code related to plug-ins management system.
:author: Mateusz Biliński <mateusz@bilinski.it>
:since: 30th May 2008
:copyright: Copyright (2008) Mateusz Biliński <mateusz@bilinski.it>
:license: GPL
'''
__all__ = ['log', 'log_calls', 'Singleton']
import logging
import functools
log = logging.getLogger('gajim.plugin_system')
'''
Logger for code related to plug-in system.
:type: logging.Logger
'''
class GajimPluginActivateException(Exception):
'''
Raised when activation failed
'''
pass
class log_calls:
'''
Decorator class for functions to easily log when they are entered and left.
'''
filter_out_classes = ['GajimPluginConfig', 'PluginManager',
'GajimPluginConfigDialog', 'PluginsWindow']
'''
List of classes from which no logs should be emited when methods are called,
even though `log_calls` decorator is used.
'''
def __init__(self, classname=''):
'''
:Keywords:
classname : str
Name of class to prefix function name (if function is a method).
log : logging.Logger
Logger to use when outputting debug information on when function has
been entered and when left. By default: `plugins.helpers.log`
is used.
'''
self.full_func_name = ''
'''
Full name of function, with class name (as prefix) if given
to decorator.
Otherwise, it's only function name retrieved from function object
for which decorator was called.
:type: str
'''
self.log_this_class = True
'''
Determines whether wrapper of given function should log calls of this
function or not.
:type: bool
'''
if classname:
self.full_func_name = classname+'.'
if classname in self.filter_out_classes:
self.log_this_class = False
def __call__(self, f):
'''
:param f: function to be wrapped with logging statements
:return: given function wrapped by *log.debug* statements
:rtype: function
'''
self.full_func_name += f.__name__
if self.log_this_class:
@functools.wraps(f)
def wrapper(*args, **kwargs):
log.debug('%(funcname)s() <entered>'%{
'funcname': self.full_func_name})
result = f(*args, **kwargs)
log.debug('%(funcname)s() <left>'%{
'funcname': self.full_func_name})
return result
else:
@functools.wraps(f)
def wrapper(*args, **kwargs):
result = f(*args, **kwargs)
return result
return wrapper
class Singleton(type):
'''
Singleton metaclass.
'''
def __init__(cls, name, bases, dic):
super(Singleton, cls).__init__(name, bases, dic)
cls.instance=None
def __call__(cls,*args,**kw):
if cls.instance is None:
cls.instance=super(Singleton, cls).__call__(*args,**kw)
#log.debug('%(classname)s - new instance created'%{
#'classname' : cls.__name__})
else:
pass
#log.debug('%(classname)s - returning already existing instance'%{
#'classname' : cls.__name__})
return cls.instance