synapse-product/synapse/util/caches/__init__.py
Patrick Cloke aec294ee0d
Use slots in attrs classes where possible (#8296)
slots use less memory (and attribute access is faster) while slightly
limiting the flexibility of the class attributes. This focuses on objects
which are instantiated "often" and for short periods of time.
2020-09-14 12:50:06 -04:00

176 lines
5.4 KiB
Python

# -*- coding: utf-8 -*-
# Copyright 2015, 2016 OpenMarket Ltd
# Copyright 2019, 2020 The Matrix.org Foundation C.I.C.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import logging
from sys import intern
from typing import Callable, Dict, Optional
import attr
from prometheus_client.core import Gauge
from synapse.config.cache import add_resizable_cache
logger = logging.getLogger(__name__)
caches_by_name = {}
collectors_by_name = {} # type: Dict
cache_size = Gauge("synapse_util_caches_cache:size", "", ["name"])
cache_hits = Gauge("synapse_util_caches_cache:hits", "", ["name"])
cache_evicted = Gauge("synapse_util_caches_cache:evicted_size", "", ["name"])
cache_total = Gauge("synapse_util_caches_cache:total", "", ["name"])
cache_max_size = Gauge("synapse_util_caches_cache_max_size", "", ["name"])
response_cache_size = Gauge("synapse_util_caches_response_cache:size", "", ["name"])
response_cache_hits = Gauge("synapse_util_caches_response_cache:hits", "", ["name"])
response_cache_evicted = Gauge(
"synapse_util_caches_response_cache:evicted_size", "", ["name"]
)
response_cache_total = Gauge("synapse_util_caches_response_cache:total", "", ["name"])
@attr.s(slots=True)
class CacheMetric:
_cache = attr.ib()
_cache_type = attr.ib(type=str)
_cache_name = attr.ib(type=str)
_collect_callback = attr.ib(type=Optional[Callable])
hits = attr.ib(default=0)
misses = attr.ib(default=0)
evicted_size = attr.ib(default=0)
def inc_hits(self):
self.hits += 1
def inc_misses(self):
self.misses += 1
def inc_evictions(self, size=1):
self.evicted_size += size
def describe(self):
return []
def collect(self):
try:
if self._cache_type == "response_cache":
response_cache_size.labels(self._cache_name).set(len(self._cache))
response_cache_hits.labels(self._cache_name).set(self.hits)
response_cache_evicted.labels(self._cache_name).set(self.evicted_size)
response_cache_total.labels(self._cache_name).set(
self.hits + self.misses
)
else:
cache_size.labels(self._cache_name).set(len(self._cache))
cache_hits.labels(self._cache_name).set(self.hits)
cache_evicted.labels(self._cache_name).set(self.evicted_size)
cache_total.labels(self._cache_name).set(self.hits + self.misses)
if getattr(self._cache, "max_size", None):
cache_max_size.labels(self._cache_name).set(self._cache.max_size)
if self._collect_callback:
self._collect_callback()
except Exception as e:
logger.warning("Error calculating metrics for %s: %s", self._cache_name, e)
raise
def register_cache(
cache_type: str,
cache_name: str,
cache,
collect_callback: Optional[Callable] = None,
resizable: bool = True,
resize_callback: Optional[Callable] = None,
) -> CacheMetric:
"""Register a cache object for metric collection and resizing.
Args:
cache_type
cache_name: name of the cache
cache: cache itself
collect_callback: If given, a function which is called during metric
collection to update additional metrics.
resizable: Whether this cache supports being resized.
resize_callback: A function which can be called to resize the cache.
Returns:
CacheMetric: an object which provides inc_{hits,misses,evictions} methods
"""
if resizable:
if not resize_callback:
resize_callback = getattr(cache, "set_cache_factor")
add_resizable_cache(cache_name, resize_callback)
metric = CacheMetric(cache, cache_type, cache_name, collect_callback)
metric_name = "cache_%s_%s" % (cache_type, cache_name)
caches_by_name[cache_name] = cache
collectors_by_name[metric_name] = metric
return metric
KNOWN_KEYS = {
key: key
for key in (
"auth_events",
"content",
"depth",
"event_id",
"hashes",
"origin",
"origin_server_ts",
"prev_events",
"room_id",
"sender",
"signatures",
"state_key",
"type",
"unsigned",
"user_id",
)
}
def intern_string(string):
"""Takes a (potentially) unicode string and interns it if it's ascii
"""
if string is None:
return None
try:
return intern(string)
except UnicodeEncodeError:
return string
def intern_dict(dictionary):
"""Takes a dictionary and interns well known keys and their values
"""
return {
KNOWN_KEYS.get(key, key): _intern_known_values(key, value)
for key, value in dictionary.items()
}
def _intern_known_values(key, value):
intern_keys = ("event_id", "room_id", "sender", "user_id", "type", "state_key")
if key in intern_keys:
return intern_string(value)
return value