Source code for logilab.common.logging_ext

# copyright 2003-2011 LOGILAB S.A. (Paris, FRANCE), all rights reserved.
# contact http://www.logilab.fr/ -- mailto:contact@logilab.fr
#
# This file is part of logilab-common.
#
# logilab-common is free software: you can redistribute it and/or modify it under
# the terms of the GNU Lesser General Public License as published by the Free
# Software Foundation, either version 2.1 of the License, or (at your option) any
# later version.
#
# logilab-common 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 Lesser General Public License for more
# details.
#
# You should have received a copy of the GNU Lesser General Public License along
# with logilab-common.  If not, see <http://www.gnu.org/licenses/>.
"""Extends the logging module from the standard library."""

__docformat__ = "restructuredtext en"

import os
import sys
import logging

from logilab.common.textutils import colorize_ansi


def set_log_methods(cls, logger):
    """bind standard logger's methods as methods on the class"""
    cls.__logger = logger
    for attr in ("debug", "info", "warning", "error", "critical", "exception"):
        setattr(cls, attr, getattr(logger, attr))


def xxx_cyan(record):
    if "XXX" in record.message:
        return "cyan"


class ColorFormatter(logging.Formatter):
    """
    A color Formatter for the logging standard module.

    By default, colorize CRITICAL and ERROR in red, WARNING in orange, INFO in
    green and DEBUG in yellow.

    self.colors is customizable via the 'color' constructor argument (dictionary).

    self.colorfilters is a list of functions that get the LogRecord
    and return a color name or None.
    """

    def __init__(self, fmt=None, datefmt=None, colors=None):
        logging.Formatter.__init__(self, fmt, datefmt)
        self.colorfilters = []
        self.colors = {
            "CRITICAL": "background_red",
            "ERROR": "red",
            "WARNING": "yellow",
            "INFO": "white",
            "DEBUG": "cyan",
        }
        if colors is not None:
            assert isinstance(colors, dict)
            self.colors.update(colors)

    def format(self, record):
        msg = logging.Formatter.format(self, record)
        if record.levelname in self.colors:
            color = self.colors[record.levelname]
            return colorize_ansi(msg, color)
        else:
            for cf in self.colorfilters:
                color = cf(record)
                if color:
                    return colorize_ansi(msg, color)
        return msg


def set_color_formatter(logger=None, **kw):
    """
    Install a color formatter on the 'logger'. If not given, it will
    defaults to the default logger.

    Any additional keyword will be passed as-is to the ColorFormatter
    constructor.
    """
    if logger is None:
        logger = logging.getLogger()
        if not logger.handlers:
            logging.basicConfig()
    format_msg = logger.handlers[0].formatter._fmt
    fmt = ColorFormatter(format_msg, **kw)
    fmt.colorfilters.append(xxx_cyan)
    logger.handlers[0].setFormatter(fmt)


LOG_FORMAT = "%(asctime)s - (%(name)s) %(levelname)s: %(message)s"
LOG_DATE_FORMAT = "%Y-%m-%d %H:%M:%S"


def get_handler(debug=False, syslog=False, logfile=None, rotation_parameters=None):
    """get an apropriate handler according to given parameters"""
    if os.environ.get("APYCOT_ROOT"):
        handler = logging.StreamHandler(sys.stdout)
    if debug:
        handler = logging.StreamHandler()
    elif logfile is None:
        if syslog:
            from logging import handlers

            handler = handlers.SysLogHandler()
        else:
            handler = logging.StreamHandler()
    else:
        try:
            if rotation_parameters is None:
                if os.name == "posix" and sys.version_info >= (2, 6):
                    from logging.handlers import WatchedFileHandler

                    handler = WatchedFileHandler(logfile)
                else:
                    handler = logging.FileHandler(logfile)
            else:
                from logging.handlers import TimedRotatingFileHandler

                handler = TimedRotatingFileHandler(logfile, **rotation_parameters)
        except OSError:
            handler = logging.StreamHandler()
    return handler


def get_threshold(debug=False, logthreshold=None):
    if logthreshold is None:
        if debug:
            logthreshold = logging.DEBUG
        else:
            logthreshold = logging.ERROR
    elif isinstance(logthreshold, str):
        logthreshold = getattr(logging, THRESHOLD_MAP.get(logthreshold, logthreshold))
    return logthreshold


def _colorable_terminal():
    isatty = hasattr(sys.__stdout__, "isatty") and sys.__stdout__.isatty()
    if not isatty:
        return False
    if os.name == "nt":
        try:
            from colorama import init as init_win32_colors
        except ImportError:
            return False
        init_win32_colors()
    return True


def get_formatter(logformat=LOG_FORMAT, logdateformat=LOG_DATE_FORMAT):
    if _colorable_terminal():
        fmt = ColorFormatter(logformat, logdateformat)

        def col_fact(record):
            if "XXX" in record.message:
                return "cyan"
            if "kick" in record.message:
                return "red"

        fmt.colorfilters.append(col_fact)
    else:
        fmt = logging.Formatter(logformat, logdateformat)
    return fmt


def init_log(
    debug=False,
    syslog=False,
    logthreshold=None,
    logfile=None,
    logformat=LOG_FORMAT,
    logdateformat=LOG_DATE_FORMAT,
    fmt=None,
    rotation_parameters=None,
    handler=None,
):
    """init the log service"""
    logger = logging.getLogger()
    if handler is None:
        handler = get_handler(debug, syslog, logfile, rotation_parameters)
    # only addHandler and removeHandler method while I would like a setHandler
    # method, so do it this way :$
    logger.handlers = [handler]
    logthreshold = get_threshold(debug, logthreshold)
    logger.setLevel(logthreshold)
    if fmt is None:
        if debug:
            fmt = get_formatter(logformat=logformat, logdateformat=logdateformat)
        else:
            fmt = logging.Formatter(logformat, logdateformat)
    handler.setFormatter(fmt)
    return handler


# map logilab.common.logger thresholds to logging thresholds
THRESHOLD_MAP = {
    "LOG_DEBUG": "DEBUG",
    "LOG_INFO": "INFO",
    "LOG_NOTICE": "INFO",
    "LOG_WARN": "WARNING",
    "LOG_WARNING": "WARNING",
    "LOG_ERR": "ERROR",
    "LOG_ERROR": "ERROR",
    "LOG_CRIT": "CRITICAL",
}