Merge pull request #2158 from matrix-org/erikj/reduce_cache_size

Reduce cache size by not storing deferreds
This commit is contained in:
Erik Johnston 2017-04-25 11:18:07 +01:00 committed by GitHub
commit b4da08cad8
3 changed files with 28 additions and 24 deletions

View file

@ -47,7 +47,10 @@ class ReceiptsStore(SQLBaseStore):
# Returns an ObservableDeferred
res = self.get_users_with_read_receipts_in_room.cache.get((room_id,), None)
if res and res.called and user_id in res.result:
if res:
if isinstance(res, defer.Deferred) and res.called:
res = res.result
if user_id in res:
# We'd only be adding to the set, so no point invalidating if the
# user is already there
return

View file

@ -18,8 +18,6 @@ import os
CACHE_SIZE_FACTOR = float(os.environ.get("SYNAPSE_CACHE_FACTOR", 0.1))
DEBUG_CACHES = False
metrics = synapse.metrics.get_metrics_for("synapse.util.caches")
caches_by_name = {}

View file

@ -19,7 +19,7 @@ from synapse.util import unwrapFirstError, logcontext
from synapse.util.caches.lrucache import LruCache
from synapse.util.caches.treecache import TreeCache, iterate_tree_cache_entry
from . import DEBUG_CACHES, register_cache
from . import register_cache
from twisted.internet import defer
from collections import namedtuple
@ -76,7 +76,7 @@ class Cache(object):
self.cache = LruCache(
max_size=max_entries, keylen=keylen, cache_type=cache_type,
size_callback=(lambda d: len(d.result)) if iterable else None,
size_callback=(lambda d: len(d)) if iterable else None,
)
self.name = name
@ -96,6 +96,17 @@ class Cache(object):
)
def get(self, key, default=_CacheSentinel, callback=None):
"""Looks the key up in the caches.
Args:
key(tuple)
default: What is returned if key is not in the caches. If not
specified then function throws KeyError instead
callback(fn): Gets called when the entry in the cache is invalidated
Returns:
Either a Deferred or the raw result
"""
callbacks = [callback] if callback else []
val = self._pending_deferred_cache.get(key, _CacheSentinel)
if val is not _CacheSentinel:
@ -137,7 +148,7 @@ class Cache(object):
if self.sequence == entry.sequence:
existing_entry = self._pending_deferred_cache.pop(key, None)
if existing_entry is entry:
self.cache.set(key, entry.deferred, entry.callbacks)
self.cache.set(key, result, entry.callbacks)
else:
entry.invalidate()
else:
@ -335,20 +346,10 @@ class CacheDescriptor(_CacheDescriptorBase):
try:
cached_result_d = cache.get(cache_key, callback=invalidate_callback)
if isinstance(cached_result_d, ObservableDeferred):
observer = cached_result_d.observe()
if DEBUG_CACHES:
@defer.inlineCallbacks
def check_result(cached_result):
actual_result = yield self.function_to_call(obj, *args, **kwargs)
if actual_result != cached_result:
logger.error(
"Stale cache entry %s%r: cached: %r, actual %r",
self.orig.__name__, cache_key,
cached_result, actual_result,
)
raise ValueError("Stale cache entry")
defer.returnValue(cached_result)
observer.addCallback(check_result)
else:
observer = cached_result_d
except KeyError:
ret = defer.maybeDeferred(
@ -447,7 +448,9 @@ class CacheListDescriptor(_CacheDescriptorBase):
try:
res = cache.get(tuple(key), callback=invalidate_callback)
if not res.has_succeeded():
if not isinstance(res, ObservableDeferred):
results[arg] = res
elif not res.has_succeeded():
res = res.observe()
res.addCallback(lambda r, arg: (arg, r), arg)
cached_defers[arg] = res