Speed up cache size calculation
Instead of calculating the size of the cache repeatedly, which can take a long time now that it can use a callback, instead cache the size and update that on insertion and deletion. This requires changing the cache descriptors to have two caches, one for pending deferreds and the other for the actual values. There's no reason to evict from the pending deferreds as they won't take up any more memory.pull/1815/head
Erik Johnston
parent
f2f179dce2
commit
f85b6ca494
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@ -17,7 +17,7 @@ import logging
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from synapse.util.async import ObservableDeferred
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from synapse.util import unwrapFirstError
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from synapse.util.caches.lrucache import LruCache
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from synapse.util.caches.treecache import TreeCache
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from synapse.util.caches.treecache import TreeCache, popped_to_iterator
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from synapse.util.logcontext import (
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PreserveLoggingContext, preserve_context_over_deferred, preserve_context_over_fn
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)
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@ -42,11 +42,23 @@ _CacheSentinel = object()
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CACHE_SIZE_FACTOR = float(os.environ.get("SYNAPSE_CACHE_FACTOR", 0.1))
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def deferred_size(deferred):
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if deferred.called:
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return len(deferred.result)
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else:
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return 1
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class CacheEntry(object):
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__slots__ = [
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"deferred", "sequence", "callbacks", "invalidated"
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]
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def __init__(self, deferred, sequence, callbacks):
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self.deferred = deferred
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self.sequence = sequence
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self.callbacks = set(callbacks)
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self.invalidated = False
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def invalidate(self):
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if not self.invalidated:
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self.invalidated = True
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for callback in self.callbacks:
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callback()
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self.callbacks.clear()
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class Cache(object):
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@ -58,13 +70,16 @@ class Cache(object):
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"sequence",
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"thread",
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"metrics",
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"_pending_deferred_cache",
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)
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def __init__(self, name, max_entries=1000, keylen=1, tree=False, iterable=False):
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cache_type = TreeCache if tree else dict
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self._pending_deferred_cache = cache_type()
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self.cache = LruCache(
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max_size=max_entries, keylen=keylen, cache_type=cache_type,
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size_callback=deferred_size if iterable else None,
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size_callback=(lambda d: len(d.result)) if iterable else None,
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)
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self.name = name
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@ -84,7 +99,15 @@ class Cache(object):
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)
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def get(self, key, default=_CacheSentinel, callback=None):
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val = self.cache.get(key, _CacheSentinel, callback=callback)
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callbacks = [callback] if callback else []
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val = self._pending_deferred_cache.get(key, _CacheSentinel)
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if val is not _CacheSentinel:
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if val.sequence == self.sequence:
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val.callbacks.update(callbacks)
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self.metrics.inc_hits()
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return val.deferred
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val = self.cache.get(key, _CacheSentinel, callbacks=callbacks)
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if val is not _CacheSentinel:
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self.metrics.inc_hits()
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return val
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@ -96,15 +119,39 @@ class Cache(object):
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else:
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return default
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def update(self, sequence, key, value, callback=None):
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def set(self, key, value, callback=None):
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callbacks = [callback] if callback else []
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self.check_thread()
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if self.sequence == sequence:
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# Only update the cache if the caches sequence number matches the
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# number that the cache had before the SELECT was started (SYN-369)
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self.prefill(key, value, callback=callback)
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entry = CacheEntry(
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deferred=value,
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sequence=self.sequence,
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callbacks=callbacks,
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)
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entry.callbacks.update(callbacks)
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existing_entry = self._pending_deferred_cache.pop(key, None)
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if existing_entry:
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existing_entry.invalidate()
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self._pending_deferred_cache[key] = entry
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def shuffle(result):
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if self.sequence == entry.sequence:
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existing_entry = self._pending_deferred_cache.pop(key, None)
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if existing_entry is entry:
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self.cache.set(key, entry.deferred, entry.callbacks)
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else:
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entry.invalidate()
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else:
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entry.invalidate()
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return result
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entry.deferred.addCallback(shuffle)
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def prefill(self, key, value, callback=None):
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self.cache.set(key, value, callback=callback)
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callbacks = [callback] if callback else []
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self.cache.set(key, value, callbacks=callbacks)
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def invalidate(self, key):
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self.check_thread()
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@ -116,6 +163,10 @@ class Cache(object):
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# Increment the sequence number so that any SELECT statements that
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# raced with the INSERT don't update the cache (SYN-369)
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self.sequence += 1
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entry = self._pending_deferred_cache.pop(key, None)
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if entry:
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entry.invalidate()
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self.cache.pop(key, None)
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def invalidate_many(self, key):
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@ -127,6 +178,12 @@ class Cache(object):
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self.sequence += 1
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self.cache.del_multi(key)
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val = self._pending_deferred_cache.pop(key, None)
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if val is not None:
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entry_dict, _ = val
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for entry in popped_to_iterator(entry_dict):
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entry.invalidate()
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def invalidate_all(self):
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self.check_thread()
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self.sequence += 1
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@ -254,11 +311,6 @@ class CacheDescriptor(object):
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return preserve_context_over_deferred(observer)
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except KeyError:
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# Get the sequence number of the cache before reading from the
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# database so that we can tell if the cache is invalidated
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# while the SELECT is executing (SYN-369)
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sequence = cache.sequence
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ret = defer.maybeDeferred(
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preserve_context_over_fn,
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self.function_to_call,
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@ -272,7 +324,7 @@ class CacheDescriptor(object):
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ret.addErrback(onErr)
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ret = ObservableDeferred(ret, consumeErrors=True)
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cache.update(sequence, cache_key, ret, callback=invalidate_callback)
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cache.set(cache_key, ret, callback=invalidate_callback)
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return preserve_context_over_deferred(ret.observe())
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@ -370,7 +422,6 @@ class CacheListDescriptor(object):
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missing.append(arg)
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if missing:
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sequence = cache.sequence
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args_to_call = dict(arg_dict)
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args_to_call[self.list_name] = missing
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@ -393,8 +444,8 @@ class CacheListDescriptor(object):
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key = list(keyargs)
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key[self.list_pos] = arg
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cache.update(
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sequence, tuple(key), observer,
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cache.set(
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tuple(key), observer,
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callback=invalidate_callback
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)
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@ -23,7 +23,9 @@ import logging
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logger = logging.getLogger(__name__)
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DictionaryEntry = namedtuple("DictionaryEntry", ("full", "value"))
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class DictionaryEntry(namedtuple("DictionaryEntry", ("full", "value"))):
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def __len__(self):
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return len(self.value)
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class DictionaryCache(object):
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@ -32,7 +34,7 @@ class DictionaryCache(object):
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"""
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def __init__(self, name, max_entries=1000):
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self.cache = LruCache(max_size=max_entries)
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self.cache = LruCache(max_size=max_entries, size_callback=len)
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self.name = name
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self.sequence = 0
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@ -56,6 +56,8 @@ class ExpiringCache(object):
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self.iterable = iterable
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self._size_estimate = 0
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def start(self):
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if not self._expiry_ms:
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# Don't bother starting the loop if things never expire
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@ -70,9 +72,14 @@ class ExpiringCache(object):
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now = self._clock.time_msec()
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self._cache[key] = _CacheEntry(now, value)
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if self.iterable:
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self._size_estimate += len(value)
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# Evict if there are now too many items
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while self._max_len and len(self) > self._max_len:
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self._cache.popitem(last=False)
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_key, value = self._cache.popitem(last=False)
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if self.iterable:
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self._size_estimate -= len(value.value)
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def __getitem__(self, key):
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try:
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@ -109,7 +116,9 @@ class ExpiringCache(object):
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keys_to_delete.add(key)
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for k in keys_to_delete:
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self._cache.pop(k)
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value = self._cache.pop(k)
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if self.iterable:
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self._size_estimate -= len(value.value)
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logger.debug(
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"[%s] _prune_cache before: %d, after len: %d",
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@ -118,7 +127,7 @@ class ExpiringCache(object):
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def __len__(self):
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if self.iterable:
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return sum(len(value.value) for value in self._cache.itervalues())
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return self._size_estimate
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else:
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return len(self._cache)
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@ -58,12 +58,6 @@ class LruCache(object):
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lock = threading.Lock()
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def cache_len():
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if size_callback is not None:
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return sum(size_callback(node.value) for node in cache.itervalues())
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else:
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return len(cache)
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def evict():
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while cache_len() > max_size:
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todelete = list_root.prev_node
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@ -78,6 +72,16 @@ class LruCache(object):
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return inner
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cached_cache_len = [0]
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if size_callback is not None:
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def cache_len():
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return cached_cache_len[0]
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else:
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def cache_len():
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return len(cache)
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self.len = synchronized(cache_len)
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def add_node(key, value, callbacks=set()):
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prev_node = list_root
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next_node = prev_node.next_node
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@ -86,6 +90,9 @@ class LruCache(object):
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next_node.prev_node = node
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cache[key] = node
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if size_callback:
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cached_cache_len[0] += size_callback(node.value)
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def move_node_to_front(node):
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prev_node = node.prev_node
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next_node = node.next_node
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@ -104,23 +111,25 @@ class LruCache(object):
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prev_node.next_node = next_node
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next_node.prev_node = prev_node
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if size_callback:
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cached_cache_len[0] -= size_callback(node.value)
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for cb in node.callbacks:
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cb()
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node.callbacks.clear()
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@synchronized
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def cache_get(key, default=None, callback=None):
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def cache_get(key, default=None, callbacks=[]):
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node = cache.get(key, None)
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if node is not None:
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move_node_to_front(node)
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if callback:
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node.callbacks.add(callback)
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node.callbacks.update(callbacks)
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return node.value
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else:
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return default
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@synchronized
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def cache_set(key, value, callback=None):
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def cache_set(key, value, callbacks=[]):
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node = cache.get(key, None)
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if node is not None:
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if value != node.value:
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@ -128,17 +137,16 @@ class LruCache(object):
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cb()
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node.callbacks.clear()
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if callback:
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node.callbacks.add(callback)
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if size_callback:
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cached_cache_len[0] -= size_callback(node.value)
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cached_cache_len[0] += size_callback(value)
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node.callbacks.update(callbacks)
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move_node_to_front(node)
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node.value = value
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else:
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if callback:
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callbacks = set([callback])
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else:
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callbacks = set()
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add_node(key, value, callbacks)
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add_node(key, value, set(callbacks))
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evict()
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@ -65,12 +65,24 @@ class TreeCache(object):
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return popped
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def values(self):
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return [e.value for e in self.root.values()]
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return list(popped_to_iterator(self.root))
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def __len__(self):
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return self.size
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def popped_to_iterator(d):
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if isinstance(d, dict):
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for value_d in d.itervalues():
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for value in popped_to_iterator(value_d):
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yield value
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else:
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if isinstance(d, _Entry):
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yield d.value
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else:
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yield d
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class _Entry(object):
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__slots__ = ["value"]
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@ -241,7 +241,7 @@ class CacheDecoratorTestCase(unittest.TestCase):
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callcount2 = [0]
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class A(object):
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@cached(max_entries=2)
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@cached(max_entries=20) # HACK: This makes it 2 due to cache factor
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def func(self, key):
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callcount[0] += 1
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return key
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@ -258,6 +258,10 @@ class CacheDecoratorTestCase(unittest.TestCase):
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self.assertEquals(callcount[0], 2)
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self.assertEquals(callcount2[0], 2)
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yield a.func2("foo")
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self.assertEquals(callcount[0], 2)
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self.assertEquals(callcount2[0], 2)
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yield a.func("foo3")
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self.assertEquals(callcount[0], 3)
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@ -93,7 +93,7 @@ class LruCacheCallbacksTestCase(unittest.TestCase):
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cache.set("key", "value")
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self.assertFalse(m.called)
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cache.get("key", callback=m)
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cache.get("key", callbacks=[m])
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self.assertFalse(m.called)
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cache.get("key", "value")
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@ -112,10 +112,10 @@ class LruCacheCallbacksTestCase(unittest.TestCase):
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cache.set("key", "value")
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self.assertFalse(m.called)
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cache.get("key", callback=m)
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cache.get("key", callbacks=[m])
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self.assertFalse(m.called)
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cache.get("key", callback=m)
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cache.get("key", callbacks=[m])
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self.assertFalse(m.called)
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cache.set("key", "value2")
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@ -128,7 +128,7 @@ class LruCacheCallbacksTestCase(unittest.TestCase):
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m = Mock()
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cache = LruCache(1)
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cache.set("key", "value", m)
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cache.set("key", "value", [m])
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self.assertFalse(m.called)
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cache.set("key", "value")
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@ -144,7 +144,7 @@ class LruCacheCallbacksTestCase(unittest.TestCase):
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m = Mock()
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cache = LruCache(1)
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cache.set("key", "value", m)
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cache.set("key", "value", [m])
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self.assertFalse(m.called)
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cache.pop("key")
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@ -163,10 +163,10 @@ class LruCacheCallbacksTestCase(unittest.TestCase):
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m4 = Mock()
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cache = LruCache(4, 2, cache_type=TreeCache)
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cache.set(("a", "1"), "value", m1)
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cache.set(("a", "2"), "value", m2)
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cache.set(("b", "1"), "value", m3)
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cache.set(("b", "2"), "value", m4)
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cache.set(("a", "1"), "value", [m1])
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cache.set(("a", "2"), "value", [m2])
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cache.set(("b", "1"), "value", [m3])
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cache.set(("b", "2"), "value", [m4])
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self.assertEquals(m1.call_count, 0)
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self.assertEquals(m2.call_count, 0)
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@ -185,8 +185,8 @@ class LruCacheCallbacksTestCase(unittest.TestCase):
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m2 = Mock()
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cache = LruCache(5)
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cache.set("key1", "value", m1)
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cache.set("key2", "value", m2)
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cache.set("key1", "value", [m1])
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cache.set("key2", "value", [m2])
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self.assertEquals(m1.call_count, 0)
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self.assertEquals(m2.call_count, 0)
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@ -202,14 +202,14 @@ class LruCacheCallbacksTestCase(unittest.TestCase):
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m3 = Mock(name="m3")
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cache = LruCache(2)
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cache.set("key1", "value", m1)
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cache.set("key2", "value", m2)
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cache.set("key1", "value", [m1])
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cache.set("key2", "value", [m2])
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self.assertEquals(m1.call_count, 0)
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self.assertEquals(m2.call_count, 0)
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self.assertEquals(m3.call_count, 0)
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cache.set("key3", "value", m3)
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cache.set("key3", "value", [m3])
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|
||||
self.assertEquals(m1.call_count, 1)
|
||||
self.assertEquals(m2.call_count, 0)
|
||||
|
|
@ -227,7 +227,7 @@ class LruCacheCallbacksTestCase(unittest.TestCase):
|
|||
self.assertEquals(m2.call_count, 0)
|
||||
self.assertEquals(m3.call_count, 0)
|
||||
|
||||
cache.set("key1", "value", m1)
|
||||
cache.set("key1", "value", [m1])
|
||||
|
||||
self.assertEquals(m1.call_count, 1)
|
||||
self.assertEquals(m2.call_count, 0)
|
||||
|
|
|
|||
Loading…
Reference in New Issue