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author | Richard van der Hoff <1389908+richvdh@users.noreply.github.com> | 2020-10-21 22:57:23 +0100 |
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committer | GitHub <noreply@github.com> | 2020-10-21 22:57:23 +0100 |
commit | 15d5553d9e3a270d2ad6d02c9d3df9152732876d (patch) | |
tree | 23f500efd69e4d39ca593ebc9c13560f1a155df4 /synapse/util/caches | |
parent | Merge pull request #8572 from matrix-org/rav/cache_hacking/2 (diff) | |
parent | fix failure case (diff) | |
download | synapse-15d5553d9e3a270d2ad6d02c9d3df9152732876d.tar.xz |
Merge pull request #8593 from matrix-org/rav/cache_hacking/3
Optimisation in DeferredCache.set
Diffstat (limited to 'synapse/util/caches')
-rw-r--r-- | synapse/util/caches/deferred_cache.py | 18 |
1 files changed, 15 insertions, 3 deletions
diff --git a/synapse/util/caches/deferred_cache.py b/synapse/util/caches/deferred_cache.py index 6c162e9f34..601305487c 100644 --- a/synapse/util/caches/deferred_cache.py +++ b/synapse/util/caches/deferred_cache.py @@ -31,6 +31,7 @@ from typing import ( from prometheus_client import Gauge from twisted.internet import defer +from twisted.python import failure from synapse.util.async_helpers import ObservableDeferred from synapse.util.caches.lrucache import LruCache @@ -214,9 +215,6 @@ class DeferredCache(Generic[KT, VT]): callbacks = [callback] if callback else [] self.check_thread() - observable = ObservableDeferred(value, consumeErrors=True) - observer = observable.observe() - entry = CacheEntry(deferred=observable, callbacks=callbacks) existing_entry = self._pending_deferred_cache.pop(key, None) if existing_entry: @@ -224,6 +222,20 @@ class DeferredCache(Generic[KT, VT]): # XXX: why don't we invalidate the entry in `self.cache` yet? + # we can save a whole load of effort if the deferred is ready. + if value.called: + result = value.result + if not isinstance(result, failure.Failure): + self.cache.set(key, result, callbacks) + return value + + # otherwise, we'll add an entry to the _pending_deferred_cache for now, + # and add callbacks to add it to the cache properly later. + + observable = ObservableDeferred(value, consumeErrors=True) + observer = observable.observe() + entry = CacheEntry(deferred=observable, callbacks=callbacks) + self._pending_deferred_cache[key] = entry def compare_and_pop(): |