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Diffstat (limited to 'synapse/util/caches/lrucache.py')
| -rw-r--r-- | synapse/util/caches/lrucache.py | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/synapse/util/caches/lrucache.py b/synapse/util/caches/lrucache.py index a4bf8fa6ae..1c5a982094 100644 --- a/synapse/util/caches/lrucache.py +++ b/synapse/util/caches/lrucache.py @@ -154,11 +154,18 @@ class LruCache(object): def cache_set(key, value, callbacks=[]): node = cache.get(key, None) if node is not None: + # We sometimes store large objects, e.g. dicts, which cause + # the inequality check to take a long time. So let's only do + # the check if we have some callbacks to call. if node.callbacks and value != node.value: for cb in node.callbacks: cb() node.callbacks.clear() + # We don't bother to protect this by value != node.value as + # generally size_callback will be cheap compared with equality + # checks. (For example, taking the size of two dicts is quicker + # than comparing them for equality.) if size_callback: cached_cache_len[0] -= size_callback(node.value) cached_cache_len[0] += size_callback(value) |