diff options
Diffstat (limited to 'synapse/util/caches')
| -rw-r--r-- | synapse/util/caches/descriptors.py | 4 | ||||
| -rw-r--r-- | synapse/util/caches/dictionary_cache.py | 6 | ||||
| -rw-r--r-- | synapse/util/caches/expiringcache.py | 6 | ||||
| -rw-r--r-- | synapse/util/caches/lrucache.py | 43 |
4 files changed, 50 insertions, 9 deletions
diff --git a/synapse/util/caches/descriptors.py b/synapse/util/caches/descriptors.py index af65bfe7b8..bf3a66eae4 100644 --- a/synapse/util/caches/descriptors.py +++ b/synapse/util/caches/descriptors.py @@ -75,6 +75,7 @@ class Cache(object): self.cache = LruCache( max_size=max_entries, keylen=keylen, cache_type=cache_type, size_callback=(lambda d: len(d)) if iterable else None, + evicted_callback=self._on_evicted, ) self.name = name @@ -83,6 +84,9 @@ class Cache(object): self.thread = None self.metrics = register_cache(name, self.cache) + def _on_evicted(self, evicted_count): + self.metrics.inc_evictions(evicted_count) + def check_thread(self): expected_thread = self.thread if expected_thread is None: diff --git a/synapse/util/caches/dictionary_cache.py b/synapse/util/caches/dictionary_cache.py index d4105822b3..1709e8b429 100644 --- a/synapse/util/caches/dictionary_cache.py +++ b/synapse/util/caches/dictionary_cache.py @@ -132,9 +132,13 @@ class DictionaryCache(object): self._update_or_insert(key, value, known_absent) def _update_or_insert(self, key, value, known_absent): - entry = self.cache.setdefault(key, DictionaryEntry(False, set(), {})) + # We pop and reinsert as we need to tell the cache the size may have + # changed + + entry = self.cache.pop(key, DictionaryEntry(False, set(), {})) entry.value.update(value) entry.known_absent.update(known_absent) + self.cache[key] = entry def _insert(self, key, value, known_absent): self.cache[key] = DictionaryEntry(True, known_absent, value) diff --git a/synapse/util/caches/expiringcache.py b/synapse/util/caches/expiringcache.py index 6ad53a6390..0aa103eecb 100644 --- a/synapse/util/caches/expiringcache.py +++ b/synapse/util/caches/expiringcache.py @@ -79,7 +79,11 @@ class ExpiringCache(object): while self._max_len and len(self) > self._max_len: _key, value = self._cache.popitem(last=False) if self.iterable: - self._size_estimate -= len(value.value) + removed_len = len(value.value) + self.metrics.inc_evictions(removed_len) + self._size_estimate -= removed_len + else: + self.metrics.inc_evictions() def __getitem__(self, key): try: diff --git a/synapse/util/caches/lrucache.py b/synapse/util/caches/lrucache.py index cf5fbb679c..1c5a982094 100644 --- a/synapse/util/caches/lrucache.py +++ b/synapse/util/caches/lrucache.py @@ -49,7 +49,24 @@ class LruCache(object): 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, size_callback=None): + def __init__(self, max_size, keylen=1, cache_type=dict, size_callback=None, + evicted_callback=None): + """ + Args: + max_size (int): + + keylen (int): + + cache_type (type): + type of underlying cache to be used. Typically one of dict + or TreeCache. + + size_callback (func(V) -> int | None): + + evicted_callback (func(int)|None): + if not None, called on eviction with the size of the evicted + entry + """ cache = cache_type() self.cache = cache # Used for introspection. list_root = _Node(None, None, None, None) @@ -61,8 +78,10 @@ class LruCache(object): def evict(): while cache_len() > max_size: todelete = list_root.prev_node - delete_node(todelete) + evicted_len = delete_node(todelete) cache.pop(todelete.key, None) + if evicted_callback: + evicted_callback(evicted_len) def synchronized(f): @wraps(f) @@ -111,12 +130,15 @@ class LruCache(object): prev_node.next_node = next_node next_node.prev_node = prev_node + deleted_len = 1 if size_callback: - cached_cache_len[0] -= size_callback(node.value) + deleted_len = size_callback(node.value) + cached_cache_len[0] -= deleted_len for cb in node.callbacks: cb() node.callbacks.clear() + return deleted_len @synchronized def cache_get(key, default=None, callbacks=[]): @@ -132,14 +154,21 @@ class LruCache(object): def cache_set(key, value, callbacks=[]): node = cache.get(key, None) if node is not None: - if value != node.value: + # 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() - if size_callback: - cached_cache_len[0] -= size_callback(node.value) - cached_cache_len[0] += size_callback(value) + # 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) node.callbacks.update(callbacks) |