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
|
