__init__.py

xen虚拟机源代码安装包

                if isinstance(obj, Logger):
                    rv = obj
                else:
                    assert isinstance(obj, PlaceHolder)
                    obj.append(alogger)
            i = string.rfind(name, ".", 0, i - 1)
        if not rv:
            rv = self.root
        alogger.parent = rv

    def _fixupChildren(self, ph, alogger):
        """
        Ensure that children of the placeholder ph are connected to the
        specified logger.
        """
        for c in ph.loggers:
            if string.find(c.parent.name, alogger.name) <> 0:
                alogger.parent = c.parent
                c.parent = alogger

#---------------------------------------------------------------------------
#   Logger classes and functions
#---------------------------------------------------------------------------

class Logger(Filterer):
    """
    Instances of the Logger class represent a single logging channel. A
    "logging channel" indicates an area of an application. Exactly how an
    "area" is defined is up to the application developer. Since an
    application can have any number of areas, logging channels are identified
    by a unique string. Application areas can be nested (e.g. an area
    of "input processing" might include sub-areas "read CSV files", "read
    XLS files" and "read Gnumeric files"). To cater for this natural nesting,
    channel names are organized into a namespace hierarchy where levels are
    separated by periods, much like the Java or Python package namespace. So
    in the instance given above, channel names might be "input" for the upper
    level, and "input.csv", "input.xls" and "input.gnu" for the sub-levels.
    There is no arbitrary limit to the depth of nesting.
    """
    def __init__(self, name, level=NOTSET):
        """
        Initialize the logger with a name and an optional level.
        """
        Filterer.__init__(self)
        self.name = name
        self.level = level
        self.parent = None
        self.propagate = 1
        self.handlers = []
        self.disabled = 0

    def setLevel(self, level):
        """
        Set the logging level of this logger.
        """
        self.level = level

#   def getRoot(self):
#       """
#       Get the root of the logger hierarchy.
#       """
#       return Logger.root

    def debug(self, msg, *args, **kwargs):
        """
        Log 'msg % args' with severity 'DEBUG'.

        To pass exception information, use the keyword argument exc_info with
        a true value, e.g.

        logger.debug("Houston, we have a %s", "thorny problem", exc_info=1)
        """
        if self.manager.disable >= DEBUG:
            return
        if DEBUG >= self.getEffectiveLevel():
            apply(self._log, (DEBUG, msg, args), kwargs)

    def info(self, msg, *args, **kwargs):
        """
        Log 'msg % args' with severity 'INFO'.

        To pass exception information, use the keyword argument exc_info with
        a true value, e.g.

        logger.info("Houston, we have a %s", "interesting problem", exc_info=1)
        """
        if self.manager.disable >= INFO:
            return
        if INFO >= self.getEffectiveLevel():
            apply(self._log, (INFO, msg, args), kwargs)

    def warning(self, msg, *args, **kwargs):
        """
        Log 'msg % args' with severity 'WARNING'.

        To pass exception information, use the keyword argument exc_info with
        a true value, e.g.

        logger.warning("Houston, we have a %s", "bit of a problem", exc_info=1)
        """
        if self.manager.disable >= WARNING:
            return
        if self.isEnabledFor(WARNING):
            apply(self._log, (WARNING, msg, args), kwargs)

    warn = warning

    def error(self, msg, *args, **kwargs):
        """
        Log 'msg % args' with severity 'ERROR'.

        To pass exception information, use the keyword argument exc_info with
        a true value, e.g.

        logger.error("Houston, we have a %s", "major problem", exc_info=1)
        """
        if self.manager.disable >= ERROR:
            return
        if self.isEnabledFor(ERROR):
            apply(self._log, (ERROR, msg, args), kwargs)

    def exception(self, msg, *args):
        """
        Convenience method for logging an ERROR with exception information.
        """
        apply(self.error, (msg,) + args, {'exc_info': 1})

    def critical(self, msg, *args, **kwargs):
        """
        Log 'msg % args' with severity 'CRITICAL'.

        To pass exception information, use the keyword argument exc_info with
        a true value, e.g.

        logger.critical("Houston, we have a %s", "major disaster", exc_info=1)
        """
        if self.manager.disable >= CRITICAL:
            return
        if CRITICAL >= self.getEffectiveLevel():
            apply(self._log, (CRITICAL, msg, args), kwargs)

    fatal = critical

    def log(self, level, msg, *args, **kwargs):
        """
        Log 'msg % args' with the severity 'level'.

        To pass exception information, use the keyword argument exc_info with
        a true value, e.g.

        logger.log(level, "We have a %s", "mysterious problem", exc_info=1)
        """
        if self.manager.disable >= level:
            return
        if self.isEnabledFor(level):
            apply(self._log, (level, msg, args), kwargs)

    def findCaller(self):
        """
        Find the stack frame of the caller so that we can note the source
        file name and line number.
        """
        f = sys._getframe(1)
        while 1:
            co = f.f_code
            filename = os.path.normcase(co.co_filename)
            if filename == _srcfile:
                f = f.f_back
                continue
            return filename, f.f_lineno

    def makeRecord(self, name, level, fn, lno, msg, args, exc_info):
        """
        A factory method which can be overridden in subclasses to create
        specialized LogRecords.
        """
        return LogRecord(name, level, fn, lno, msg, args, exc_info)

    def _log(self, level, msg, args, exc_info=None):
        """
        Low-level logging routine which creates a LogRecord and then calls
        all the handlers of this logger to handle the record.
        """
        if _srcfile:
            fn, lno = self.findCaller()
        else:
            fn, lno = "<unknown file>", 0
        if exc_info:
            if type(exc_info) != types.TupleType:
                exc_info = sys.exc_info()
        record = self.makeRecord(self.name, level, fn, lno, msg, args, exc_info)
        self.handle(record)

    def handle(self, record):
        """
        Call the handlers for the specified record.

        This method is used for unpickled records received from a socket, as
        well as those created locally. Logger-level filtering is applied.
        """
        if (not self.disabled) and self.filter(record):
            self.callHandlers(record)

    def addHandler(self, hdlr):
        """
        Add the specified handler to this logger.
        """
        if not (hdlr in self.handlers):
            self.handlers.append(hdlr)

    def removeHandler(self, hdlr):
        """
        Remove the specified handler from this logger.
        """
        if hdlr in self.handlers:
            #hdlr.close()
            self.handlers.remove(hdlr)

    def callHandlers(self, record):
        """
        Pass a record to all relevant handlers.

        Loop through all handlers for this logger and its parents in the
        logger hierarchy. If no handler was found, output a one-off error
        message to sys.stderr. Stop searching up the hierarchy whenever a
        logger with the "propagate" attribute set to zero is found - that
        will be the last logger whose handlers are called.
        """
        c = self
        found = 0
        while c:
            for hdlr in c.handlers:
                found = found + 1
                if record.levelno >= hdlr.level:
                    hdlr.handle(record)
            if not c.propagate:
                c = None    #break out
            else:
                c = c.parent
        if (found == 0) and not self.manager.emittedNoHandlerWarning:
            sys.stderr.write("No handlers could be found for logger"
                             " \"%s\"\n" % self.name)
            self.manager.emittedNoHandlerWarning = 1

    def getEffectiveLevel(self):
        """
        Get the effective level for this logger.

        Loop through this logger and its parents in the logger hierarchy,
        looking for a non-zero logging level. Return the first one found.
        """
        logger = self
        while logger:
            if logger.level:
                return logger.level
            logger = logger.parent
        return NOTSET

    def isEnabledFor(self, level):
        """
        Is this logger enabled for level 'level'?
        """
        if self.manager.disable >= level:
            return 0
        return level >= self.getEffectiveLevel()

class RootLogger(Logger):
    """
    A root logger is not that different to any other logger, except that
    it must have a logging level and there is only one instance of it in
    the hierarchy.
    """
    def __init__(self, level):
        """
        Initialize the logger with the name "root".
        """
        Logger.__init__(self, "root", level)

_loggerClass = Logger

root = RootLogger(WARNING)
Logger.root = root
Logger.manager = Manager(Logger.root)

#---------------------------------------------------------------------------
# Configuration classes and functions
#---------------------------------------------------------------------------

BASIC_FORMAT = "%(levelname)s:%(name)s:%(message)s"

def basicConfig():
    """
    Do basic configuration for the logging system by creating a
    StreamHandler with a default Formatter and adding it to the
    root logger.
    """
    if len(root.handlers) == 0:
        hdlr = StreamHandler()
        fmt = Formatter(BASIC_FORMAT)
        hdlr.setFormatter(fmt)
        root.addHandler(hdlr)

#---------------------------------------------------------------------------
# Utility functions at module level.
# Basically delegate everything to the root logger.
#---------------------------------------------------------------------------

def getLogger(name=None):
    """
    Return a logger with the specified name, creating it if necessary.

    If no name is specified, return the root logger.
    """
    if name:
        return Logger.manager.getLogger(name)
    else:
        return root

#def getRootLogger():
#    """
#    Return the root logger.
#
#    Note that getLogger('') now does the same thing, so this function is
#    deprecated and may disappear in the future.
#    """
#    return root

def critical(msg, *args, **kwargs):
    """
    Log a message with severity 'CRITICAL' on the root logger.
    """
    if len(root.handlers) == 0:
        basicConfig()
    apply(root.critical, (msg,)+args, kwargs)

fatal = critical

def error(msg, *args, **kwargs):
    """
    Log a message with severity 'ERROR' on the root logger.
    """
    if len(root.handlers) == 0:
        basicConfig()
    apply(root.error, (msg,)+args, kwargs)

def exception(msg, *args):
    """
    Log a message with severity 'ERROR' on the root logger,
    with exception information.
    """
    apply(error, (msg,)+args, {'exc_info': 1})

def warning(msg, *args, **kwargs):
    """
    Log a message with severity 'WARNING' on the root logger.
    """
    if len(root.handlers) == 0:
        basicConfig()
    apply(root.warning, (msg,)+args, kwargs)

warn = warning

def info(msg, *args, **kwargs):
    """
    Log a message with severity 'INFO' on the root logger.
    """
    if len(root.handlers) == 0:
        basicConfig()
    apply(root.info, (msg,)+args, kwargs)

def debug(msg, *args, **kwargs):
    """
    Log a message with severity 'DEBUG' on the root logger.
    """
    if len(root.handlers) == 0:
        basicConfig()
    apply(root.debug, (msg,)+args, kwargs)

def disable(level):
    """
    Disable all logging calls less severe than 'level'.
    """
    root.manager.disable = level

def shutdown():
    """
    Perform any cleanup actions in the logging system (e.g. flushing
    buffers).

    Should be called at application exit.
    """
    for h in _handlers.keys():
        h.flush()
        h.close()

#Let's try and shutdown automatically on application exit...
try:
    import atexit
    atexit.register(shutdown)
except ImportError: # for Python versions < 2.0
    def exithook(status, old_exit=sys.exit):
        try:
            shutdown()
        finally:
            old_exit(status)

    sys.exit = exithook