Call logging decorator

autolog.py

# Written by Brendan O'Connor, brenocon@gmail.com, www.anyall.org
#  * Originally written Aug. 2005
#  * Posted to gist.github.com/16173 on Oct. 2008

#   Copyright (c) 2003-2006 Open Source Applications Foundation
#
#   Licensed under the Apache License, Version 2.0 (the "License");
#   you may not use this file except in compliance with the License.
#   You may obtain a copy of the License at
#
#       http://www.apache.org/licenses/LICENSE-2.0
#
#   Unless required by applicable law or agreed to in writing, software
#   distributed under the License is distributed on an "AS IS" BASIS,
#   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
#   See the License for the specific language governing permissions and
#   limitations under the License.

import logging
import random
import re
import types
from types import ClassType


"""
Again modified to make it actually work.
2014, Ulrich Petri


This file has been *heavily* modified to remove the use of global variables, implement
a logging class instead of relying on sys.stdout, remove the function log decorator, remove
the module log decorator, allow color changing on any log call,
allow indentation level changing on any log call, and PEP-8 formatting.

Copyright (C) 2013 Ben Gelb
"""


BLACK = "\033[0;30m"
BLUE = "\033[0;34m"
GREEN = "\033[0;32m"
CYAN = "\033[0;36m"
RED = "\033[0;31m"
PURPLE = "\033[0;35m"
BROWN = "\033[0;33m"
GRAY = "\033[0;37m"
BOLDGRAY = "\033[1;30m"
BOLDBLUE = "\033[1;34m"
BOLDGREEN = "\033[1;32m"
BOLDCYAN = "\033[1;36m"
BOLDRED = "\033[1;31m"
BOLDPURPLE = "\033[1;35m"
BOLDYELLOW = "\033[1;33m"
WHITE = "\033[1;37m"
NORMAL = "\033[0m"


class Logger(object):
    def __init__(self, indent_string='    ', indent_level=0, *args, **kwargs):
        self.__log = None
        self.indent_string = indent_string
        self.indent_level = indent_level

    @property
    def __logger(self):
        if not self.__log:
            FORMAT = '%(asctime)s - %(levelname)s - %(message)s'
            self.__log = logging.getLogger(__name__)
            # self.__log.setLevel(logging.DEBUG)
            # handler = logging.StreamHandler()
            # handler.setLevel(logging.DEBUG)
            # handler.setFormatter(logging.Formatter(FORMAT))
            # self.__log.addHandler(handler)
        return self.__log

    def _log_levels(self, level):
        return {
            'debug': 10,
            'info': 20,
            'warning': 30,
            'critical': 40,
            'error': 50
        }.get(level, 'info')

    def update_indent_level(self, val):
        self.indent_level = val

    def log(self, message, color=None, log_level='info', indent_level=None, args=None, **kwargs):
        msg_params = {
            'color': color or NORMAL,
            'indent': self.indent_string * (indent_level or self.indent_level),
            'msg': message
        }
        _message = "{color} {indent}{msg}".format(**msg_params)
        args = [] if not args else args
        self.__logger.log(self._log_levels(log_level), _message, *args)


def format_args(args, kwargs):
    """
    makes a nice string representation of all the arguments
    """
    allargs = []
    for item in args:
        allargs.append('%s' % str(item))

    for key, item in kwargs.items():
        allargs.append('%s=%s' % (key, str(item)))

    formattedArgs = ', '.join(allargs)

    if len(formattedArgs) > 150:
        return formattedArgs[:146] + " ..."
    return formattedArgs


logger = Logger()


def log_method(method, display_name=None):
    """use this for class or instance methods, it formats with the object out front."""
    display_name = display_name or method.__name__

    def _wrapper(self, *args, **kwargs):
        arg_str = format_args(args, kwargs)
        message = "{self_str}.{cls_color}{method_display_name}{method_color} ({arg_str})".format(**{
            'self_str': str(self),
            'cls_color': BROWN,
            'method_display_name': "{} - {}".format(method.__name__, display_name),
            'method_color': NORMAL,
            'arg_str': arg_str
        })
        logger.log(message)
        try:
            logger.update_indent_level(logger.indent_level + 1)
            returnval = method(self, *args, **kwargs)
            logger.log("Return value: %s", args=(returnval,))
            return returnval
        except Exception as ex:
            logger.log("Exception while calling method: %s", args=(ex,))
            raise
        finally:
            logger.update_indent_level(logger.indent_level - 1)
    return _wrapper


def log_class(log_match=".*", log_no_match="asdfnomatch", display_name=None):
    def decorator(cls):
        display_name_ = display_name or "%s" % (cls.__name__)
        names_to_check = cls.__dict__.keys()
        allow = lambda s: all([
            re.match(log_match, s),
            not re.match(log_no_match, s),
            s not in ('__str__', '__repr__')
        ])

        for name in names_to_check:
            if not allow(name):
                continue

            # unbound methods show up as mere functions in the values of
            # cls.__dict__,so we have to go through getattr
            value = getattr(cls, name)

            if isinstance(value, types.MethodType):
                # a normal instance method
                if value.im_self is None:
                    setattr(cls, name, log_method(value, display_name=display_name_))

                # check for cls method. class & static method are more complex.
                elif value.im_self == cls:
                    _display_name = "%s.%s" % (cls.__name__, value.__name__)
                    w = log_method(value.im_func, display_name=_display_name)
                    setattr(cls, name, classmethod(w))
                else:
                    assert False
        return cls
    if isinstance(log_match, ClassType):
        raise TypeError("log_class needs to be called")
    return decorator