moved some libraries in Bcfg2/ into more specific (Server/ or Client/) places

1 files changed, 118 insertions, 0 deletions

diff --git a/src/lib/Bcfg2/Server/Statistics.py b/src/lib/Bcfg2/Server/Statistics.py
new file mode 100644
index 000000000..8a6ff54c4
--- /dev/null
+++ b/src/lib/Bcfg2/Server/Statistics.py
@@ -0,0 +1,118 @@
+""" Module for tracking execution time statistics from the Bcfg2
+server core.  This data is exposed by
+:func:`Bcfg2.Server.Core.BaseCore.get_statistics`."""
+
+import time
+from Bcfg2.Compat import wraps
+
+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
+        """
+        self.name = name
+        self.min = float(initial_value)
+        self.max = float(initial_value)
+        self.ave = float(initial_value)
+        self.count = 1
+
+    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, value)
+        self.max = max(self.max, value)
+        self.ave = (((self.ave * (self.count - 1)) + value) / self.count)
+        self.count += 1
+
+    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.name, (self.min, self.max, self.ave, self.count))
+
+
+class Statistics(object):
+    """ A collection of named :class:`Statistic` objects. """
+
+    def __init__(self):
+        self.data = dict()
+
+    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 self.data:
+            self.data[name] = Statistic(name, value)
+        else:
+            self.data[name].add_value(value)
+
+    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(self.data.values())])
+
+
+#: A module-level :class:`Statistics` objects used to track all
+#: execution time metrics for the server.
+stats = Statistics()  # pylint: disable=C0103
+
+
+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_
+        self.name = name
+
+    def __call__(self, func):
+        if self.name is None:
+            self.name = func.__name__
+
+        @wraps(func)
+        def inner(obj, *args, **kwargs):
+            """ The decorated function """
+            name = "%s:%s" % (obj.__class__.__name__, self.name)
+
+            start = time.time()
+            try:
+                return func(obj, *args, **kwargs)
+            finally:
+                stats.add_value(name, time.time() - start)
+
+        return inner