diff options
Diffstat (limited to 'synapse/util/caches/lrucache.py')
| -rw-r--r-- | synapse/util/caches/lrucache.py | 39 |
1 files changed, 32 insertions, 7 deletions
diff --git a/synapse/util/caches/lrucache.py b/synapse/util/caches/lrucache.py index f9df445a8d..9c4c679175 100644 --- a/synapse/util/caches/lrucache.py +++ b/synapse/util/caches/lrucache.py @@ -30,13 +30,14 @@ def enumerate_leaves(node, depth): class _Node(object): - __slots__ = ["prev_node", "next_node", "key", "value"] + __slots__ = ["prev_node", "next_node", "key", "value", "callbacks"] - def __init__(self, prev_node, next_node, key, value): + def __init__(self, prev_node, next_node, key, value, callbacks=set()): self.prev_node = prev_node self.next_node = next_node self.key = key self.value = value + self.callbacks = callbacks class LruCache(object): @@ -44,6 +45,9 @@ class LruCache(object): Least-recently-used cache. Supports del_multi only if cache_type=TreeCache If cache_type=TreeCache, all keys must be tuples. + + Can also set callbacks on objects when getting/setting which are fired + when that key gets invalidated/evicted. """ def __init__(self, max_size, keylen=1, cache_type=dict): cache = cache_type() @@ -62,10 +66,10 @@ class LruCache(object): return inner - def add_node(key, value): + 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) + node = _Node(prev_node, next_node, key, value, callbacks) prev_node.next_node = node next_node.prev_node = node cache[key] = node @@ -88,23 +92,41 @@ class LruCache(object): prev_node.next_node = next_node next_node.prev_node = prev_node + for cb in node.callbacks: + cb() + node.callbacks.clear() + @synchronized - def cache_get(key, default=None): + def cache_get(key, default=None, callback=None): node = cache.get(key, None) if node is not None: move_node_to_front(node) + if callback: + node.callbacks.add(callback) return node.value else: return default @synchronized - def cache_set(key, value): + def cache_set(key, value, callback=None): node = cache.get(key, None) if node is not None: + if value != node.value: + for cb in node.callbacks: + cb() + node.callbacks.clear() + + if callback: + node.callbacks.add(callback) + move_node_to_front(node) node.value = value else: - add_node(key, value) + if callback: + callbacks = set([callback]) + else: + callbacks = set() + add_node(key, value, callbacks) if len(cache) > max_size: todelete = list_root.prev_node delete_node(todelete) @@ -148,6 +170,9 @@ class LruCache(object): def cache_clear(): list_root.next_node = list_root list_root.prev_node = list_root + for node in cache.values(): + for cb in node.callbacks: + cb() cache.clear() @synchronized |