MatrixSynapse/synapse/config/cache.py

101 lines
3.2 KiB
Python

# -*- coding: utf-8 -*-
# Copyright 2019 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 os
from collections import defaultdict
from typing import DefaultDict
from twisted.logger import Logger
from ._base import Config, ConfigError
log = Logger()
_CACHES = {}
DEFAULT_CACHE_SIZE_FACTOR = float(os.environ.get("SYNAPSE_CACHE_FACTOR", 0.5))
_DEFAULT_CONFIG = """\
# Cache configuration
#
# 'global_factor' controls the global cache factor. This overrides the
# "SYNAPSE_CACHE_FACTOR" environment variable.
#
# 'per_cache_factors' is a dictionary of cache name to cache factor for that
# individual cache.
#
#caches:
# global_factor: 0.5
# per_cache_factors:
# get_users_who_share_room_with_user: 2
#
"""
def add_resizable_cache(cache_name, cache_resize_callback):
_CACHES[cache_name.lower()] = cache_resize_callback
class CacheConfig(Config):
section = "caches"
def read_config(self, config, **kwargs):
global DEFAULT_CACHE_SIZE_FACTOR
cache_config = config.get("caches", {})
self.global_factor = cache_config.get(
"global_factor", DEFAULT_CACHE_SIZE_FACTOR
)
if not isinstance(self.global_factor, (int, float)):
raise ConfigError("caches.global_factor must be a number.")
# Set the global one so that it's reflected in new caches
DEFAULT_CACHE_SIZE_FACTOR = self.global_factor
individual_factors = cache_config.get("per_cache_factors", {}) or {}
if not isinstance(individual_factors, dict):
raise ConfigError("caches.per_cache_factors must be a dictionary")
self.cache_factors = defaultdict(
lambda: self.global_factor
) # type: DefaultDict[str, float]
for cache, factor in individual_factors.items():
if not isinstance(factor, (int, float)):
raise ConfigError(
"caches.per_cache_factors.%s must be a number" % (cache.lower(),)
)
self.cache_factors[cache.lower()] = factor
def resize_caches(self):
for cache_name, cache_resize_callback in _CACHES.items():
cache_factor = self.cache_factors[cache_name]
log.debug(
"Setting cache factor for {cache_name} to {new_cache_factor}",
cache_name=cache_name,
new_cache_factor=cache_factor,
)
changed = cache_resize_callback(cache_factor)
if changed:
log.info(
"Cache factor for {cache_name} set to {new_cache_factor}",
cache_name=cache_name,
new_cache_factor=cache_factor,
)
def get_factor_for(self, cache_name):
return self.cache_factors[cache_name.lower()]