# Copyright (C) 2012 Canonical Ltd.

# Copyright (C) 2012 Yahoo! Inc.

#

# Author: Scott Moser <scott.moser@canonical.com>

# Author: Joshua Harlow <harlowja@yahoo-inc.com>

#

# This file is part of cloud-init. See LICENSE file for license information.

import imp

import logging

import sys

# Default fallback format

FALL_FORMAT = ('FALLBACK: %(asctime)s - %(filename)s[%(levelname)s]: ' +

               '%(message)s')

class QuietStreamHandler(logging.StreamHandler):

    def handleError(self, record):

        pass

def _patch_logging():

    # Replace 'handleError' with one that will be more

    # tolerant of errors in that it can avoid

    # re-notifying on exceptions and when errors

    # do occur, it can at least try to write to

    # sys.stderr using a fallback logger

    fallback_handler = QuietStreamHandler(sys.stderr)

    fallback_handler.setFormatter(logging.Formatter(FALL_FORMAT))

    def handleError(self, record):

        try:

            fallback_handler.handle(record)

            fallback_handler.flush()

        except IOError:

            pass

    setattr(logging.Handler, 'handleError', handleError)

def patch():

    imp.acquire_lock()

    try:

        _patch_logging()

    finally:

        imp.release_lock()

# vi: ts=4 expandtab