Source code for Bcfg2.Server.Statistics

""" Module for tracking execution time statistics from the Bcfg2
server core.  This data is exposed by

import time
from Bcfg2.Compat import wraps

[docs]class Statistic(object): """ A single named statistic, tracking minimum, maximum, and average execution time, and number of invocations. """ def __init__(self, name, initial_value): """ :param name: The name of this statistic :type name: string :param initial_value: The initial value to be added to this statistic :type initial_value: int or float """ = name self.min = float(initial_value) self.max = float(initial_value) self.ave = float(initial_value) self.count = 1
[docs] def add_value(self, value): """ Add a value to the statistic, recalculating the various metrics. :param value: The value to add to this statistic :type value: int or float """ self.min = min(self.min, float(value)) self.max = max(self.max, float(value)) self.count += 1 self.ave = (((self.ave * (self.count - 1)) + value) / self.count)
[docs] def get_value(self): """ Get a tuple of all the stats tracked on this named item. The tuple is in the format:: (<name>, (min, max, average, number of values)) This makes it very easy to cast to a dict in :func:`Statistics.display`. :returns: tuple """ return (, (self.min, self.max, self.ave, self.count))
def __repr__(self): return "%s(%s, (min=%s, avg=%s, max=%s, count=%s))" % ( self.__class__.__name__,, self.min, self.ave, self.max, self.count)
[docs]class Statistics(object): """ A collection of named :class:`Statistic` objects. """ def __init__(self): = dict()
[docs] def add_value(self, name, value): """ Add a value to the named :class:`Statistic`. This just proxies to :func:`Statistic.add_value` or the :class:`Statistic` constructor as appropriate. :param name: The name of the :class:`Statistic` to add the value to :type name: string :param value: The value to add to the Statistic :type value: int or float """ if name not in[name] = Statistic(name, value) else:[name].add_value(value)
[docs] def display(self): """ Return a dict of all :class:`Statistic` object values. Keys are the statistic names, and values are tuples of the statistic metrics as returned by :func:`Statistic.get_value`. """ return dict([value.get_value() for value in list(]) #: A module-level :class:`Statistics` objects used to track all #: execution time metrics for the server.
stats = Statistics() # pylint: disable=C0103
[docs]class track_statistics(object): # pylint: disable=C0103 """ Decorator that tracks execution time for the given method with :mod:`Bcfg2.Server.Statistics` for reporting via ``bcfg2-admin perf`` """ def __init__(self, name=None): """ :param name: The name under which statistics for this function will be tracked. By default, the name will be the name of the function concatenated with the name of the class the function is a member of. :type name: string """ # if this is None, it will be set later during __call_ = name def __call__(self, func): if is None: = func.__name__ @wraps(func) def inner(obj, *args, **kwargs): """ The decorated function """ name = "%s:%s" % (obj.__class__.__name__, start = time.time() try: return func(obj, *args, **kwargs) finally: stats.add_value(name, time.time() - start) return inner