Ensure invalidation list does not grow unboundedly

This commit is contained in:
Erik Johnston 2016-08-19 15:58:52 +01:00
parent c0d7d9d642
commit 45fd2c8942
4 changed files with 104 additions and 20 deletions

View File

@ -25,6 +25,7 @@ from synapse.util.logcontext import (
from . import DEBUG_CACHES, register_cache
from twisted.internet import defer
from collections import namedtuple
import os
import functools
@ -210,16 +211,17 @@ class CacheDescriptor(object):
# whenever we are invalidated
invalidate_callback = kwargs.pop("on_invalidate", None)
# Add our own `cache_context` to argument list if the wrapped function
# has asked for one
self_context = _CacheContext(cache, None)
# Add temp cache_context so inspect.getcallargs doesn't explode
if self.add_cache_context:
kwargs["cache_context"] = self_context
kwargs["cache_context"] = None
arg_dict = inspect.getcallargs(self.orig, obj, *args, **kwargs)
cache_key = tuple(arg_dict[arg_nm] for arg_nm in self.arg_names)
self_context.key = cache_key
# Add our own `cache_context` to argument list if the wrapped function
# has asked for one
if self.add_cache_context:
kwargs["cache_context"] = _CacheContext(cache, cache_key)
try:
cached_result_d = cache.get(cache_key, callback=invalidate_callback)
@ -414,13 +416,7 @@ class CacheListDescriptor(object):
return wrapped
class _CacheContext(object):
__slots__ = ["cache", "key"]
def __init__(self, cache, key):
self.cache = cache
self.key = key
class _CacheContext(namedtuple("_CacheContext", ("cache", "key"))):
def invalidate(self):
self.cache.invalidate(self.key)

View File

@ -32,7 +32,7 @@ def enumerate_leaves(node, depth):
class _Node(object):
__slots__ = ["prev_node", "next_node", "key", "value", "callbacks"]
def __init__(self, prev_node, next_node, key, value, callbacks=[]):
def __init__(self, prev_node, next_node, key, value, callbacks=set()):
self.prev_node = prev_node
self.next_node = next_node
self.key = key
@ -66,7 +66,7 @@ class LruCache(object):
return inner
def add_node(key, value, callbacks=[]):
def add_node(key, value, callbacks=set()):
prev_node = list_root
next_node = prev_node.next_node
node = _Node(prev_node, next_node, key, value, callbacks)
@ -94,7 +94,7 @@ class LruCache(object):
for cb in node.callbacks:
cb()
node.callbacks = []
node.callbacks.clear()
@synchronized
def cache_get(key, default=None, callback=None):
@ -102,7 +102,7 @@ class LruCache(object):
if node is not None:
move_node_to_front(node)
if callback:
node.callbacks.append(callback)
node.callbacks.add(callback)
return node.value
else:
return default
@ -114,18 +114,18 @@ class LruCache(object):
if value != node.value:
for cb in node.callbacks:
cb()
node.callbacks = []
node.callbacks.clear()
if callback:
node.callbacks.append(callback)
node.callbacks.add(callback)
move_node_to_front(node)
node.value = value
else:
if callback:
callbacks = [callback]
callbacks = set([callback])
else:
callbacks = []
callbacks = set()
add_node(key, value, callbacks)
if len(cache) > max_size:
todelete = list_root.prev_node

View File

@ -17,6 +17,8 @@
from tests import unittest
from twisted.internet import defer
from mock import Mock
from synapse.util.async import ObservableDeferred
from synapse.util.caches.descriptors import Cache, cached
@ -265,3 +267,49 @@ class CacheDecoratorTestCase(unittest.TestCase):
self.assertEquals(callcount[0], 4)
self.assertEquals(callcount2[0], 3)
@defer.inlineCallbacks
def test_double_get(self):
callcount = [0]
callcount2 = [0]
class A(object):
@cached()
def func(self, key):
callcount[0] += 1
return key
@cached(cache_context=True)
def func2(self, key, cache_context):
callcount2[0] += 1
return self.func(key, on_invalidate=cache_context.invalidate)
a = A()
a.func2.cache.cache = Mock(wraps=a.func2.cache.cache)
yield a.func2("foo")
self.assertEquals(callcount[0], 1)
self.assertEquals(callcount2[0], 1)
a.func2.invalidate(("foo",))
self.assertEquals(a.func2.cache.cache.pop.call_count, 1)
yield a.func2("foo")
a.func2.invalidate(("foo",))
self.assertEquals(a.func2.cache.cache.pop.call_count, 2)
self.assertEquals(callcount[0], 1)
self.assertEquals(callcount2[0], 2)
a.func.invalidate(("foo",))
self.assertEquals(a.func2.cache.cache.pop.call_count, 3)
yield a.func("foo")
self.assertEquals(callcount[0], 2)
self.assertEquals(callcount2[0], 2)
yield a.func2("foo")
self.assertEquals(callcount[0], 2)
self.assertEquals(callcount2[0], 3)

View File

@ -50,6 +50,8 @@ class LruCacheTestCase(unittest.TestCase):
self.assertEquals(cache.get("key"), 1)
self.assertEquals(cache.setdefault("key", 2), 1)
self.assertEquals(cache.get("key"), 1)
cache["key"] = 2 # Make sure overriding works.
self.assertEquals(cache.get("key"), 2)
def test_pop(self):
cache = LruCache(1)
@ -84,6 +86,44 @@ class LruCacheTestCase(unittest.TestCase):
class LruCacheCallbacksTestCase(unittest.TestCase):
def test_get(self):
m = Mock()
cache = LruCache(1)
cache.set("key", "value")
self.assertFalse(m.called)
cache.get("key", callback=m)
self.assertFalse(m.called)
cache.get("key", "value")
self.assertFalse(m.called)
cache.set("key", "value2")
self.assertEquals(m.call_count, 1)
cache.set("key", "value")
self.assertEquals(m.call_count, 1)
def test_multi_get(self):
m = Mock()
cache = LruCache(1)
cache.set("key", "value")
self.assertFalse(m.called)
cache.get("key", callback=m)
self.assertFalse(m.called)
cache.get("key", callback=m)
self.assertFalse(m.called)
cache.set("key", "value2")
self.assertEquals(m.call_count, 1)
cache.set("key", "value")
self.assertEquals(m.call_count, 1)
def test_set(self):
m = Mock()
cache = LruCache(1)