1 # Copyright (C) 2010 Chris Jerdonek (cjerdonek@webkit.org)

     2 #

     3 # Redistribution and use in source and binary forms, with or without

     4 # modification, are permitted provided that the following conditions

     5 # are met:

     6 # 1.  Redistributions of source code must retain the above copyright

     7 #     notice, this list of conditions and the following disclaimer.

     8 # 2.  Redistributions in binary form must reproduce the above copyright

     9 #     notice, this list of conditions and the following disclaimer in the

    10 #     documentation and/or other materials provided with the distribution.

    11 #

    12 # THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS'' AND

    13 # ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED

    14 # WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE

    15 # DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS BE LIABLE FOR

    16 # ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL

    17 # DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR

    18 # SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER

    19 # CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,

    20 # OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE

    21 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

    22 

    23 """Supports webkitpy logging."""

    24 

    25 # FIXME: Move this file to webkitpy/python24 since logging needs to

    26 #        be configured prior to running version-checking code.

    27 

    28 import logging

    29 import os

    30 import sys

    31 

    32 import webkitpy

    33 

    34 

    35 _log = logging.getLogger(__name__)

    36 

    37 # We set these directory paths lazily in get_logger() below.

    38 _scripts_dir = ""

    39 """The normalized, absolute path to the ...Scripts directory."""

    40 

    41 _webkitpy_dir = ""

    42 """The normalized, absolute path to the ...Scripts/webkitpy directory."""

    43 

    44 

    45 def _normalize_path(path):

    46     """Return the given path normalized.

    47 

    48     Converts a path to an absolute path, removes any trailing slashes,

    49     removes any extension, and lower-cases it.

    50 

    51     """

    52     path = os.path.abspath(path)

    53     path = os.path.normpath(path)

    54     path = os.path.splitext(path)[0]  # Remove the extension, if any.

    55     path = path.lower()

    56 

    57     return path

    58 

    59 

    60 # Observe that the implementation of this function does not require

    61 # the use of any hard-coded strings like "webkitpy", etc.

    62 #

    63 # The main benefit this function has over using--

    64 #

    65 # _log = logging.getLogger(__name__)

    66 #

    67 # is that get_logger() returns the same value even if __name__ is

    68 # "__main__" -- i.e. even if the module is the script being executed

    69 # from the command-line.

    70 def get_logger(path):

    71     """Return a logging.logger for the given path.

    72 

    73     Returns:

    74       A logger whose name is the name of the module corresponding to

    75       the given path.  If the module is in webkitpy, the name is

    76       the fully-qualified dotted module name beginning with webkitpy....

    77       Otherwise, the name is the base name of the module (i.e. without

    78       any dotted module name prefix).

    79 

    80     Args:

    81       path: The path of the module.  Normally, this parameter should be

    82             the __file__ variable of the module.

    83 

    84     Sample usage:

    85 

    86       import webkitpy.common.system.logutils as logutils

    87 

    88       _log = logutils.get_logger(__file__)

    89 

    90     """

    91     # Since we assign to _scripts_dir and _webkitpy_dir in this function,

    92     # we need to declare them global.

    93     global _scripts_dir

    94     global _webkitpy_dir

    95 

    96     path = _normalize_path(path)

    97 

    98     # Lazily evaluate _webkitpy_dir and _scripts_dir.

    99     if not _scripts_dir:

   100         # The normalized, absolute path to ...Scripts/webkitpy/__init__.

   101         webkitpy_path = _normalize_path(webkitpy.__file__)

   102 

   103         _webkitpy_dir = os.path.split(webkitpy_path)[0]

   104         _scripts_dir = os.path.split(_webkitpy_dir)[0]

   105 

   106     if path.startswith(_webkitpy_dir):

   107         # Remove the initial Scripts directory portion, so the path

   108         # starts with /webkitpy, for example "/webkitpy/init/logutils".

   109         path = path[len(_scripts_dir):]

   110 

   111         parts = []

   112         while True:

   113             (path, tail) = os.path.split(path)

   114             if not tail:

   115                 break

   116             parts.insert(0, tail)

   117 

   118         logger_name = ".".join(parts)  # For example, webkitpy.common.system.logutils.

   119     else:

   120         # The path is outside of webkitpy.  Default to the basename

   121         # without the extension.

   122         basename = os.path.basename(path)

   123         logger_name = os.path.splitext(basename)[0]

   124 

   125     return logging.getLogger(logger_name)

   126 

   127 

   128 def _default_handlers(stream):

   129     """Return a list of the default logging handlers to use.

   130 

   131     Args:

   132       stream: See the configure_logging() docstring.

   133 

   134     """

   135     # Create the filter.

   136     def should_log(record):

   137         """Return whether a logging.LogRecord should be logged."""

   138         # FIXME: Enable the logging of autoinstall messages once

   139         #        autoinstall is adjusted.  Currently, autoinstall logs

   140         #        INFO messages when importing already-downloaded packages,

   141         #        which is too verbose.

   142         if record.name.startswith("webkitpy.thirdparty.autoinstall"):

   143             return False

   144         return True

   145 

   146     logging_filter = logging.Filter()

   147     logging_filter.filter = should_log

   148 

   149     # Create the handler.

   150     handler = logging.StreamHandler(stream)

   151     formatter = logging.Formatter("%(name)s: [%(levelname)s] %(message)s")

   152     handler.setFormatter(formatter)

   153     handler.addFilter(logging_filter)

   154 

   155     return [handler]

   156 

   157 

   158 def configure_logging(logging_level=None, logger=None, stream=None,

   159                       handlers=None):

   160     """Configure logging for standard purposes.

   161 

   162     Returns:

   163       A list of references to the logging handlers added to the root

   164       logger.  This allows the caller to later remove the handlers

   165       using logger.removeHandler.  This is useful primarily during unit

   166       testing where the caller may want to configure logging temporarily

   167       and then undo the configuring.

   168 

   169     Args:

   170       logging_level: The minimum logging level to log.  Defaults to

   171                      logging.INFO.

   172       logger: A logging.logger instance to configure.  This parameter

   173               should be used only in unit tests.  Defaults to the

   174               root logger.

   175       stream: A file-like object to which to log used in creating the default

   176               handlers.  The stream must define an "encoding" data attribute,

   177               or else logging raises an error.  Defaults to sys.stderr.

   178       handlers: A list of logging.Handler instances to add to the logger

   179                 being configured.  If this parameter is provided, then the

   180                 stream parameter is not used.

   181 

   182     """

   183     # If the stream does not define an "encoding" data attribute, the

   184     # logging module can throw an error like the following:

   185     #

   186     # Traceback (most recent call last):

   187     #   File "/System/Library/Frameworks/Python.framework/Versions/2.6/...

   188     #         lib/python2.6/logging/__init__.py", line 761, in emit

   189     #     self.stream.write(fs % msg.encode(self.stream.encoding))

   190     # LookupError: unknown encoding: unknown

   191     if logging_level is None:

   192         logging_level = logging.INFO

   193     if logger is None:

   194         logger = logging.getLogger()

   195     if stream is None:

   196         stream = sys.stderr

   197     if handlers is None:

   198         handlers = _default_handlers(stream)

   199 

   200     logger.setLevel(logging_level)

   201 

   202     for handler in handlers:

   203         logger.addHandler(handler)

   204 

   205     _log.debug("Debug logging enabled.")

   206 

   207     return handlers