1 # Copyright 2009 the Melange authors.

     2 #

     3 # Licensed under the Apache License, Version 2.0 (the "License");

     4 # you may not use this file except in compliance with the License.

     5 # You may obtain a copy of the License at

     6 #

     7 #   http://www.apache.org/licenses/LICENSE-2.0

     8 #

     9 # Unless required by applicable law or agreed to in writing, software

    10 # distributed under the License is distributed on an "AS IS" BASIS,

    11 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

    12 # See the License for the specific language governing permissions and

    13 # limitations under the License.

    14 

    15 """Logging facilities.

    16 

    17 The public interface is basically an initialization function for the

    18 underlying Python logging module. Logging always goes to the console,

    19 and can optionally be configured to write to a transcript file, which

    20 will store exactly what appears on screen (minus colors).

    21 """

    22 

    23 __authors__ = [

    24     # alphabetical order by last name, please

    25     '"David Anderson" <dave@natulte.net>',

    26     ]

    27 

    28 import logging

    29 

    30 import util

    31 

    32 

    33 class _ColorizingFormatter(logging.Formatter):

    34   """A logging formatter that colorizes based on log levels."""

    35 

    36   def format(self, record):

    37     msg = logging.Formatter.format(self, record)

    38 

    39     if record.levelno >= logging.WARNING:

    40       return util.colorize(msg, util.RED, bold=True)

    41     elif record.levelno == logging.INFO:

    42       return util.colorize(msg, util.GREEN)

    43     else:

    44       return msg

    45 

    46 

    47 class _DecolorizingFormatter(logging.Formatter):

    48   """A logging formatter that strips color."""

    49 

    50   def format(self, record):

    51     return util.decolorize(logging.Formatter.format(self, record))

    52 

    53 

    54 def init(logfile=None):

    55   """Initialize the logging subsystem.

    56 

    57   Args:

    58     logfile: The filename for the transcript file, if any.

    59   """

    60 

    61   root = logging.getLogger('')

    62   root.setLevel(logging.DEBUG)

    63 

    64   console = logging.StreamHandler()

    65   console.setLevel(logging.DEBUG)

    66   console.setFormatter(_ColorizingFormatter())

    67   root.addHandler(console)

    68 

    69   if logfile:

    70     transcript = logging.FileHandler(logfile, 'w')

    71     transcript.setLevel(logging.DEBUG)

    72     transcript.setFormatter(_DecolorizingFormatter())

    73     root.addHandler(transcript)

    74 

    75 

    76 debug = logging.debug

    77 info = logging.info

    78 error = logging.error