def __init__(self):
self.max = 0
self.min = sys.maxint
self.count = 0
self.histogram = Histogram()
self.mean = 0.0
self.partial_variance = 0.0
self.lock = threading.Lock()
class Timing(object):
def __init__(self):
self.max = 0
self.min = sys.maxint
self.count = 0
self.histogram = Histogram()
self.mean = 0.0
self.partial_variance = 0.0
self.lock = threading.Lock()
def clear(self):
"""Resets the state of this Timing. Clears the durations and counts
collected so far.
"""
with self.lock:
self.max = 0
self.min = sys.maxint
self.count = 0
self.histogram.clear()
def add(self, n):
if isinstance(n, TimingStat):
return self.add_timing_stat(n)
else:
return self.add_duration(n)
def add_duration(self, n):
"""Adds a duration to our current Timing."""
with self.lock:
if n > -1:
self.max = max(self.max, n)
self.min = min(self.min, n)
self.count += 1
self.histogram.add(n)
if self.count == 1:
self.mean = float(n)
self.partial_variance = 0.0
else:
new_mean = self.mean + (n - self.mean) / self.count
self.partial_variance += (n - self.mean) * (n - new_mean)
self.mean = new_mean
else:
# TODO: warning?
pass
return self.count
def add_timing_stat(self, timing_stat):
"""Add a summarized set of timings."""
with self.lock:
if timing_stat.count > 0:
# (comment from Scala ostrich) these equations end up using the sum again, and may be lossy. i couldn't find or think of
# a better way.
new_mean = (self.mean * self.count + timing_stat.mean * timing_stat.count) / (self.count + timing_stat.count)
self.partial_variance = self.partial_variance + timing_stat.partial_variance + \
(self.mean - new_mean) * self.mean * self.count + \
(timing_stat.mean - new_mean) * timing_stat.mean * timing_stat.count
self.mean = new_mean
self.count += timing_stat.count
self.max = max(self.max, timing_stat.max)
self.min = min(self.min, timing_stat.min)
if timing_stat.histogram is not None:
self.histogram.merge(timing_stat.histogram)
def get(self, reset=False):
"""Returns a TimingStat for the measured event."""
with self.lock:
try:
return TimingStat(self.count, self.max, self.min, self.mean, self.partial_variance, self.histogram.clone())
finally:
if reset:
self.max = 0
self.min = sys.maxint
self.count = 0
self.histogram.clear()
def from_raw_dict(cls, d, bucket_offsets=None):
histogram = None
if d.has_key('histogram'):
histogram = Histogram.from_list(d['histogram'], bucket_offsets)
return TimingStat(d['count'], d['max'], d['min'], d['mean'], d['partial_variance'], histogram)
