Small optimisation to CacheListDescriptor

This commit is contained in:
Erik Johnston 2016-06-02 11:52:32 +01:00
parent 597013caa5
commit e043ede4a2
3 changed files with 21 additions and 14 deletions

View File

@ -15,7 +15,6 @@
from itertools import chain from itertools import chain
from collections import Counter
# TODO(paul): I can't believe Python doesn't have one of these # TODO(paul): I can't believe Python doesn't have one of these
@ -56,29 +55,30 @@ class CounterMetric(BaseMetric):
"""The simplest kind of metric; one that stores a monotonically-increasing """The simplest kind of metric; one that stores a monotonically-increasing
integer that counts events.""" integer that counts events."""
__slots__ = ("counts")
def __init__(self, *args, **kwargs): def __init__(self, *args, **kwargs):
super(CounterMetric, self).__init__(*args, **kwargs) super(CounterMetric, self).__init__(*args, **kwargs)
self.counts = Counter() self.counts = {}
# Scalar metrics are never empty # Scalar metrics are never empty
if self.is_scalar(): if self.is_scalar():
self.counts[()] = 0 self.counts[()] = 0
def inc_by(self, incr, *values): def inc_by(self, incr, *values):
# if len(values) != self.dimension(): if len(values) != self.dimension():
# raise ValueError( raise ValueError(
# "Expected as many values to inc() as labels (%d)" % (self.dimension()) "Expected as many values to inc() as labels (%d)" % (self.dimension())
# ) )
# TODO: should assert that the tag values are all strings # TODO: should assert that the tag values are all strings
self.counts[values] += incr if values not in self.counts:
self.counts[values] = incr
else:
self.counts[values] += incr
def inc(self, *values): def inc(self, *values):
self.counts[values] += 1 self.inc_by(1, *values)
def render_item(self, k): def render_item(self, k):
return ["%s%s %d" % (self.name, self._render_key(k), self.counts[k])] return ["%s%s %d" % (self.name, self._render_key(k), self.counts[k])]
@ -132,8 +132,6 @@ class CacheMetric(object):
This metric generates standard metric name pairs, so that monitoring rules This metric generates standard metric name pairs, so that monitoring rules
can easily be applied to measure hit ratio.""" can easily be applied to measure hit ratio."""
__slots__ = ("name", "hits", "total", "size")
def __init__(self, name, size_callback, labels=[]): def __init__(self, name, size_callback, labels=[]):
self.name = name self.name = name

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@ -102,6 +102,15 @@ class ObservableDeferred(object):
def observers(self): def observers(self):
return self._observers return self._observers
def has_called(self):
return self._result is not None
def has_succeeded(self):
return self._result is not None and self._result[0] is True
def get_result(self):
return self._result[1]
def __getattr__(self, name): def __getattr__(self, name):
return getattr(self._deferred, name) return getattr(self._deferred, name)

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@ -311,12 +311,12 @@ class CacheListDescriptor(object):
try: try:
res = cache.get(tuple(key)) res = cache.get(tuple(key))
if not res.called: if not res.has_succeeded():
res = res.observe() res = res.observe()
res.addCallback(lambda r, arg: (arg, r), arg) res.addCallback(lambda r, arg: (arg, r), arg)
cached_defers[arg] = res cached_defers[arg] = res
else: else:
results[arg] = res.result results[arg] = res.get_result()
except KeyError: except KeyError:
missing.append(arg) missing.append(arg)