Merge pull request #65 from matrix-org/get_event_cache

Add an in-memory cache for get_event in the storage layer
This commit is contained in:
Mark Haines 2015-02-11 15:44:09 +00:00
commit 40f332e534
8 changed files with 210 additions and 6 deletions

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@ -27,6 +27,16 @@ class Config(object):
def __init__(self, args):
pass
@staticmethod
def parse_size(string):
sizes = {"K": 1024, "M": 1024 * 1024}
size = 1
suffix = string[-1]
if suffix in sizes:
string = string[:-1]
size = sizes[suffix]
return int(string) * size
@staticmethod
def abspath(file_path):
return os.path.abspath(file_path) if file_path else file_path

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@ -24,6 +24,7 @@ class DatabaseConfig(Config):
self.database_path = ":memory:"
else:
self.database_path = self.abspath(args.database_path)
self.event_cache_size = self.parse_size(args.event_cache_size)
@classmethod
def add_arguments(cls, parser):
@ -33,6 +34,10 @@ class DatabaseConfig(Config):
"-d", "--database-path", default="homeserver.db",
help="The database name."
)
db_group.add_argument(
"--event-cache-size", default="100K",
help="Number of events to cache in memory."
)
@classmethod
def generate_config(cls, args, config_dir_path):

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@ -164,6 +164,9 @@ class DataStore(RoomMemberStore, RoomStore,
stream_ordering=None, is_new_state=True,
current_state=None):
# Remove the any existing cache entries for the event_id
self._get_event_cache.pop(event.event_id)
# We purposefully do this first since if we include a `current_state`
# key, we *want* to update the `current_state_events` table
if current_state:
@ -420,6 +423,8 @@ class DataStore(RoomMemberStore, RoomStore,
)
def _store_redaction(self, txn, event):
# invalidate the cache for the redacted event
self._get_event_cache.pop(event.redacts)
txn.execute(
"INSERT OR IGNORE INTO redactions "
"(event_id, redacts) VALUES (?,?)",

View File

@ -19,6 +19,7 @@ from synapse.events import FrozenEvent
from synapse.events.utils import prune_event
from synapse.util.logutils import log_function
from synapse.util.logcontext import PreserveLoggingContext, LoggingContext
from synapse.util.lrucache import LruCache
from twisted.internet import defer
@ -128,6 +129,8 @@ class SQLBaseStore(object):
self._txn_perf_counters = PerformanceCounters()
self._get_event_counters = PerformanceCounters()
self._get_event_cache = LruCache(hs.config.event_cache_size)
def start_profiling(self):
self._previous_loop_ts = self._clock.time_msec()
@ -579,6 +582,19 @@ class SQLBaseStore(object):
def _get_event_txn(self, txn, event_id, check_redacted=True,
get_prev_content=False, allow_rejected=False):
start_time = time.time() * 1000
update_counter = self._get_event_counters.update
try:
cache = self._get_event_cache.setdefault(event_id, {})
# Separate cache entries for each way to invoke _get_event_txn
return cache[(check_redacted, get_prev_content, allow_rejected)]
except KeyError:
pass
finally:
start_time = update_counter("event_cache", start_time)
sql = (
"SELECT e.internal_metadata, e.json, r.event_id, rej.reason "
"FROM event_json as e "
@ -588,8 +604,6 @@ class SQLBaseStore(object):
"LIMIT 1 "
)
start_time = time.time() * 1000
txn.execute(sql, (event_id,))
res = txn.fetchone()
@ -599,14 +613,16 @@ class SQLBaseStore(object):
internal_metadata, js, redacted, rejected_reason = res
self._get_event_counters.update("select_event", start_time)
start_time = update_counter("select_event", start_time)
if allow_rejected or not rejected_reason:
return self._get_event_from_row_txn(
result = self._get_event_from_row_txn(
txn, internal_metadata, js, redacted,
check_redacted=check_redacted,
get_prev_content=get_prev_content,
)
cache[(check_redacted, get_prev_content, allow_rejected)] = result
return result
else:
return None

110
synapse/util/lrucache.py Normal file
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@ -0,0 +1,110 @@
# -*- coding: utf-8 -*-
# Copyright 2015 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.
class LruCache(object):
"""Least-recently-used cache."""
# TODO(mjark) Add hit/miss counters
# TODO(mjark) Add mutex for linked list for thread safety.
def __init__(self, max_size):
cache = {}
list_root = []
list_root[:] = [list_root, list_root, None, None]
PREV, NEXT, KEY, VALUE = 0, 1, 2, 3
def add_node(key, value):
prev_node = list_root
next_node = prev_node[NEXT]
node = [prev_node, next_node, key, value]
prev_node[NEXT] = node
next_node[PREV] = node
cache[key] = node
def move_node_to_front(node):
prev_node = node[PREV]
next_node = node[NEXT]
prev_node[NEXT] = next_node
next_node[PREV] = prev_node
prev_node = list_root
next_node = prev_node[NEXT]
node[PREV] = prev_node
node[NEXT] = next_node
prev_node[NEXT] = node
next_node[PREV] = node
def delete_node(node):
prev_node = node[PREV]
next_node = node[NEXT]
prev_node[NEXT] = next_node
next_node[PREV] = prev_node
cache.pop(node[KEY], None)
def cache_get(key, default=None):
node = cache.get(key, None)
if node is not None:
move_node_to_front(node)
return node[VALUE]
else:
return default
def cache_set(key, value):
node = cache.get(key, None)
if node is not None:
move_node_to_front(node)
node[VALUE] = value
else:
add_node(key, value)
if len(cache) > max_size:
delete_node(list_root[PREV])
def cache_set_default(key, value):
node = cache.get(key, None)
if node is not None:
return node[VALUE]
else:
add_node(key, value)
if len(cache) > max_size:
delete_node(list_root[PREV])
return value
def cache_pop(key, default=None):
node = cache.get(key, None)
if node:
delete_node(node)
return node[VALUE]
else:
return default
self.sentinel = object()
self.get = cache_get
self.set = cache_set
self.setdefault = cache_set_default
self.pop = cache_pop
def __getitem__(self, key):
result = self.get(key, self.sentinel)
if result is self.sentinel:
raise KeyError()
else:
return result
def __setitem__(self, key, value):
self.set(key, value)
def __delitem__(self, key, value):
result = self.pop(key, self.sentinel)
if result is self.sentinel:
raise KeyError()

View File

@ -38,8 +38,9 @@ class SQLBaseStoreTestCase(unittest.TestCase):
return defer.succeed(func(self.mock_txn, *args, **kwargs))
self.db_pool.runInteraction = runInteraction
hs = HomeServer("test",
db_pool=self.db_pool)
config = Mock()
config.event_cache_size = 1
hs = HomeServer("test", db_pool=self.db_pool, config=config)
self.datastore = SQLBaseStore(hs)

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@ -0,0 +1,56 @@
# -*- coding: utf-8 -*-
# Copyright 2015 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 .. import unittest
from synapse.util.lrucache import LruCache
class LruCacheTestCase(unittest.TestCase):
def test_get_set(self):
cache = LruCache(1)
cache["key"] = "value"
self.assertEquals(cache.get("key"), "value")
self.assertEquals(cache["key"], "value")
def test_eviction(self):
cache = LruCache(2)
cache[1] = 1
cache[2] = 2
self.assertEquals(cache.get(1), 1)
self.assertEquals(cache.get(2), 2)
cache[3] = 3
self.assertEquals(cache.get(1), None)
self.assertEquals(cache.get(2), 2)
self.assertEquals(cache.get(3), 3)
def test_setdefault(self):
cache = LruCache(1)
self.assertEquals(cache.setdefault("key", 1), 1)
self.assertEquals(cache.get("key"), 1)
self.assertEquals(cache.setdefault("key", 2), 1)
self.assertEquals(cache.get("key"), 1)
def test_pop(self):
cache = LruCache(1)
cache["key"] = 1
self.assertEquals(cache.pop("key"), 1)
self.assertEquals(cache.pop("key"), None)

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@ -41,6 +41,7 @@ def setup_test_homeserver(name="test", datastore=None, config=None, **kargs):
if config is None:
config = Mock()
config.signing_key = [MockKey()]
config.event_cache_size = 1
if datastore is None:
db_pool = SQLiteMemoryDbPool()