forked from MirrorHub/synapse
Remove SnapshotCache in favour of ResponseCache
This commit is contained in:
parent
e1544b0af8
commit
f166a8d1f5
|
@ -26,7 +26,7 @@ from synapse.streams.config import PaginationConfig
|
|||
from synapse.types import StreamToken, UserID
|
||||
from synapse.util import unwrapFirstError
|
||||
from synapse.util.async_helpers import concurrently_execute
|
||||
from synapse.util.caches.snapshot_cache import SnapshotCache
|
||||
from synapse.util.caches.response_cache import ResponseCache
|
||||
from synapse.visibility import filter_events_for_client
|
||||
|
||||
from ._base import BaseHandler
|
||||
|
@ -41,7 +41,7 @@ class InitialSyncHandler(BaseHandler):
|
|||
self.state = hs.get_state_handler()
|
||||
self.clock = hs.get_clock()
|
||||
self.validator = EventValidator()
|
||||
self.snapshot_cache = SnapshotCache()
|
||||
self.snapshot_cache = ResponseCache(hs, "initial_sync_cache")
|
||||
self._event_serializer = hs.get_event_client_serializer()
|
||||
self.storage = hs.get_storage()
|
||||
self.state_store = self.storage.state
|
||||
|
@ -79,17 +79,14 @@ class InitialSyncHandler(BaseHandler):
|
|||
as_client_event,
|
||||
include_archived,
|
||||
)
|
||||
now_ms = self.clock.time_msec()
|
||||
result = self.snapshot_cache.get(now_ms, key)
|
||||
if result is not None:
|
||||
return result
|
||||
|
||||
return self.snapshot_cache.set(
|
||||
now_ms,
|
||||
return self.snapshot_cache.wrap(
|
||||
key,
|
||||
self._snapshot_all_rooms(
|
||||
user_id, pagin_config, as_client_event, include_archived
|
||||
),
|
||||
self._snapshot_all_rooms,
|
||||
user_id,
|
||||
pagin_config,
|
||||
as_client_event,
|
||||
include_archived,
|
||||
)
|
||||
|
||||
@defer.inlineCallbacks
|
||||
|
|
|
@ -1,94 +0,0 @@
|
|||
# -*- coding: utf-8 -*-
|
||||
# Copyright 2015, 2016 OpenMarket Ltd
|
||||
#
|
||||
# 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.
|
||||
|
||||
from synapse.util.async_helpers import ObservableDeferred
|
||||
|
||||
|
||||
class SnapshotCache(object):
|
||||
"""Cache for snapshots like the response of /initialSync.
|
||||
The response of initialSync only has to be a recent snapshot of the
|
||||
server state. It shouldn't matter to clients if it is a few minutes out
|
||||
of date.
|
||||
|
||||
This caches a deferred response. Until the deferred completes it will be
|
||||
returned from the cache. This means that if the client retries the request
|
||||
while the response is still being computed, that original response will be
|
||||
used rather than trying to compute a new response.
|
||||
|
||||
Once the deferred completes it will removed from the cache after 5 minutes.
|
||||
We delay removing it from the cache because a client retrying its request
|
||||
could race with us finishing computing the response.
|
||||
|
||||
Rather than tracking precisely how long something has been in the cache we
|
||||
keep two generations of completed responses. Every 5 minutes discard the
|
||||
old generation, move the new generation to the old generation, and set the
|
||||
new generation to be empty. This means that a result will be in the cache
|
||||
somewhere between 5 and 10 minutes.
|
||||
"""
|
||||
|
||||
DURATION_MS = 5 * 60 * 1000 # Cache results for 5 minutes.
|
||||
|
||||
def __init__(self):
|
||||
self.pending_result_cache = {} # Request that haven't finished yet.
|
||||
self.prev_result_cache = {} # The older requests that have finished.
|
||||
self.next_result_cache = {} # The newer requests that have finished.
|
||||
self.time_last_rotated_ms = 0
|
||||
|
||||
def rotate(self, time_now_ms):
|
||||
# Rotate once if the cache duration has passed since the last rotation.
|
||||
if time_now_ms - self.time_last_rotated_ms >= self.DURATION_MS:
|
||||
self.prev_result_cache = self.next_result_cache
|
||||
self.next_result_cache = {}
|
||||
self.time_last_rotated_ms += self.DURATION_MS
|
||||
|
||||
# Rotate again if the cache duration has passed twice since the last
|
||||
# rotation.
|
||||
if time_now_ms - self.time_last_rotated_ms >= self.DURATION_MS:
|
||||
self.prev_result_cache = self.next_result_cache
|
||||
self.next_result_cache = {}
|
||||
self.time_last_rotated_ms = time_now_ms
|
||||
|
||||
def get(self, time_now_ms, key):
|
||||
self.rotate(time_now_ms)
|
||||
# This cache is intended to deduplicate requests, so we expect it to be
|
||||
# missed most of the time. So we just lookup the key in all of the
|
||||
# dictionaries rather than trying to short circuit the lookup if the
|
||||
# key is found.
|
||||
result = self.prev_result_cache.get(key)
|
||||
result = self.next_result_cache.get(key, result)
|
||||
result = self.pending_result_cache.get(key, result)
|
||||
if result is not None:
|
||||
return result.observe()
|
||||
else:
|
||||
return None
|
||||
|
||||
def set(self, time_now_ms, key, deferred):
|
||||
self.rotate(time_now_ms)
|
||||
|
||||
result = ObservableDeferred(deferred)
|
||||
|
||||
self.pending_result_cache[key] = result
|
||||
|
||||
def shuffle_along(r):
|
||||
# When the deferred completes we shuffle it along to the first
|
||||
# generation of the result cache. So that it will eventually
|
||||
# expire from the rotation of that cache.
|
||||
self.next_result_cache[key] = result
|
||||
self.pending_result_cache.pop(key, None)
|
||||
return r
|
||||
|
||||
result.addBoth(shuffle_along)
|
||||
|
||||
return result.observe()
|
|
@ -1,63 +0,0 @@
|
|||
# -*- coding: utf-8 -*-
|
||||
# Copyright 2015, 2016 OpenMarket Ltd
|
||||
#
|
||||
# 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.
|
||||
|
||||
|
||||
from twisted.internet.defer import Deferred
|
||||
|
||||
from synapse.util.caches.snapshot_cache import SnapshotCache
|
||||
|
||||
from .. import unittest
|
||||
|
||||
|
||||
class SnapshotCacheTestCase(unittest.TestCase):
|
||||
def setUp(self):
|
||||
self.cache = SnapshotCache()
|
||||
self.cache.DURATION_MS = 1
|
||||
|
||||
def test_get_set(self):
|
||||
# Check that getting a missing key returns None
|
||||
self.assertEquals(self.cache.get(0, "key"), None)
|
||||
|
||||
# Check that setting a key with a deferred returns
|
||||
# a deferred that resolves when the initial deferred does
|
||||
d = Deferred()
|
||||
set_result = self.cache.set(0, "key", d)
|
||||
self.assertIsNotNone(set_result)
|
||||
self.assertFalse(set_result.called)
|
||||
|
||||
# Check that getting the key before the deferred has resolved
|
||||
# returns a deferred that resolves when the initial deferred does.
|
||||
get_result_at_10 = self.cache.get(10, "key")
|
||||
self.assertIsNotNone(get_result_at_10)
|
||||
self.assertFalse(get_result_at_10.called)
|
||||
|
||||
# Check that the returned deferreds resolve when the initial deferred
|
||||
# does.
|
||||
d.callback("v")
|
||||
self.assertTrue(set_result.called)
|
||||
self.assertTrue(get_result_at_10.called)
|
||||
|
||||
# Check that getting the key after the deferred has resolved
|
||||
# before the cache expires returns a resolved deferred.
|
||||
get_result_at_11 = self.cache.get(11, "key")
|
||||
self.assertIsNotNone(get_result_at_11)
|
||||
if isinstance(get_result_at_11, Deferred):
|
||||
# The cache may return the actual result rather than a deferred
|
||||
self.assertTrue(get_result_at_11.called)
|
||||
|
||||
# Check that getting the key after the deferred has resolved
|
||||
# after the cache expires returns None
|
||||
get_result_at_12 = self.cache.get(12, "key")
|
||||
self.assertIsNone(get_result_at_12)
|
Loading…
Reference in a new issue