Merge pull request #662 from matrix-org/erikj/state_cache

Make StateHandler._state_cache only store event_ids.

1 files changed, 28 insertions, 37 deletions

diff --git a/synapse/state.py b/synapse/state.py
index e096329721..41d32e664a 100644
--- a/synapse/state.py
+++ b/synapse/state.py
@@ -28,6 +28,7 @@ from collections import namedtuple
 
 import logging
 import hashlib
+import os
 
 logger = logging.getLogger(__name__)
 
@@ -35,8 +36,11 @@ logger = logging.getLogger(__name__)
 KeyStateTuple = namedtuple("KeyStateTuple", ("context", "type", "state_key"))
 
 
-SIZE_OF_CACHE = 1000
-EVICTION_TIMEOUT_SECONDS = 20
+CACHE_SIZE_FACTOR = float(os.environ.get("SYNAPSE_CACHE_FACTOR", 0.1))
+
+
+SIZE_OF_CACHE = int(1000 * CACHE_SIZE_FACTOR)
+EVICTION_TIMEOUT_SECONDS = 60 * 60
 
 
 class _StateCacheEntry(object):
@@ -86,16 +90,8 @@ class StateHandler(object):
         """
         event_ids = yield self.store.get_latest_event_ids_in_room(room_id)
 
-        cache = None
-        if self._state_cache is not None:
-            cache = self._state_cache.get(frozenset(event_ids), None)
-
-        if cache:
-            cache.ts = self.clock.time_msec()
-            state = cache.state
-        else:
-            res = yield self.resolve_state_groups(room_id, event_ids)
-            state = res[1]
+        res = yield self.resolve_state_groups(room_id, event_ids)
+        state = res[1]
 
         if event_type:
             defer.returnValue(state.get((event_type, state_key)))
@@ -187,20 +183,6 @@ class StateHandler(object):
         """
         logger.debug("resolve_state_groups event_ids %s", event_ids)
 
-        if self._state_cache is not None:
-            cache = self._state_cache.get(frozenset(event_ids), None)
-            if cache and cache.state_group:
-                cache.ts = self.clock.time_msec()
-                prev_state = cache.state.get((event_type, state_key), None)
-                if prev_state:
-                    prev_state = prev_state.event_id
-                    prev_states = [prev_state]
-                else:
-                    prev_states = []
-                defer.returnValue(
-                    (cache.state_group, cache.state, prev_states)
-                )
-
         state_groups = yield self.store.get_state_groups(
             room_id, event_ids
         )
@@ -210,7 +192,7 @@ class StateHandler(object):
             state_groups.keys()
         )
 
-        group_names = set(state_groups.keys())
+        group_names = frozenset(state_groups.keys())
         if len(group_names) == 1:
             name, state_list = state_groups.items().pop()
             state = {
@@ -224,16 +206,25 @@ class StateHandler(object):
             else:
                 prev_states = []
 
-            if self._state_cache is not None:
-                cache = _StateCacheEntry(
-                    state=state,
-                    state_group=name,
-                    ts=self.clock.time_msec()
-                )
+            defer.returnValue((name, state, prev_states))
+
+        if self._state_cache is not None:
+            cache = self._state_cache.get(group_names, None)
+            if cache and cache.state_group:
+                cache.ts = self.clock.time_msec()
 
-                self._state_cache[frozenset(event_ids)] = cache
+                event_dict = yield self.store.get_events(cache.state.values())
+                state = {(e.type, e.state_key): e for e in event_dict.values()}
 
-            defer.returnValue((name, state, prev_states))
+                prev_state = state.get((event_type, state_key), None)
+                if prev_state:
+                    prev_state = prev_state.event_id
+                    prev_states = [prev_state]
+                else:
+                    prev_states = []
+                defer.returnValue(
+                    (cache.state_group, state, prev_states)
+                )
 
         new_state, prev_states = self._resolve_events(
             state_groups.values(), event_type, state_key
@@ -241,12 +232,12 @@ class StateHandler(object):
 
         if self._state_cache is not None:
             cache = _StateCacheEntry(
-                state=new_state,
+                state={key: event.event_id for key, event in new_state.items()},
                 state_group=None,
                 ts=self.clock.time_msec()
             )
 
-            self._state_cache[frozenset(event_ids)] = cache
+            self._state_cache[group_names] = cache
 
         defer.returnValue((None, new_state, prev_states))