WIP: Completely change how event streaming and pagination work. This reflects the change in the underlying storage model.

synapse/streams/events.py

@@ -0,0 +1,149 @@
+# -*- coding: utf-8 -*-
+# Copyright 2014 matrix.org
+#
+# 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 import defer
+
+from synapse.api.constants import Membership
+from synapse.types import StreamToken
+
+
+class RoomEventSource(object):
+    SIGNAL_NAME = "EventStreamSourceSignal"
+
+    def __init__(self, hs):
+        self.store = hs.get_datastore()
+
+    @defer.inlineCallbacks
+    def get_keys_for_user(self, user):
+        events = yield self.store.get_rooms_for_user_where_membership_is(
+            user.to_string(),
+            (Membership.JOIN,),
+        )
+
+        defer.returnValue(set([e.room_id for e in events]))
+
+    @defer.inlineCallbacks
+    def get_new_events_for_user(self, user, from_token, limit, key=None):
+        # We just ignore the key for now.
+
+        to_key = yield self.get_current_token_part()
+
+        events, end_key = yield self.store.get_room_events_stream(
+            user_id=user.to_string(),
+            from_key=from_token.events_key,
+            to_key=to_key,
+            room_id=None,
+            limit=limit,
+        )
+
+        end_token = from_token.copy_and_replace("events_key", end_key)
+
+        defer.returnValue((events, end_token))
+
+    def get_current_token_part(self):
+        return self.store.get_room_events_max_id()
+
+    @defer.inlineCallbacks
+    def get_pagination_rows(self, from_token, to_token, limit, key):
+        to_key = to_token.events_key if to_token else None
+
+        events, next_key = yield self.store.paginate_room_events(
+            room_id=key,
+            from_key=from_token.events_key,
+            to_key=to_key,
+            direction='b',
+            limit=limit,
+            with_feedback=True
+        )
+
+        next_token = from_token.copy_and_replace("events_key", next_key)
+
+        defer.returnValue((events, next_token))
+
+
+class PresenceStreamSource(object):
+    def __init__(self, hs):
+        self.hs = hs
+        self.clock = hs.get_clock()
+
+    def get_new_events_for_user(self, user, from_token, limit, key=None):
+        from_key = int(from_token.presence_key)
+
+        presence = self.hs.get_handlers().presence_handler
+        cachemap = presence._user_cachemap
+
+        # TODO(paul): limit, and filter by visibility
+        updates = [(k, cachemap[k]) for k in cachemap
+                   if from_key < cachemap[k].serial]
+
+        if updates:
+            clock = self.clock
+
+            latest_serial = max([x[1].serial for x in updates])
+            data = [x[1].make_event(user=x[0], clock=clock) for x in updates]
+
+            end_token = from_token.copy_and_replace(
+                "presence_key", latest_serial
+            )
+            return ((data, end_token))
+        else:
+            end_token = from_token.copy_and_replace(
+                "presence_key", presence._user_cachemap_latest_serial
+            )
+            return (([], end_token))
+
+    def get_keys_for_user(self, user):
+        raise NotImplementedError("get_keys_for_user")
+
+    def get_current_token_part(self):
+        presence = self.hs.get_handlers().presence_handler
+        return presence._user_cachemap_latest_serial
+
+
+class EventSources(object):
+    SOURCE_TYPES = [
+        RoomEventSource,
+        PresenceStreamSource,
+    ]
+
+    def __init__(self, hs):
+        self.sources = [t(hs) for t in EventSources.SOURCE_TYPES]
+
+    @staticmethod
+    def create_token(events_key, presence_key):
+        return StreamToken(events_key=events_key, presence_key=presence_key)
+
+    @defer.inlineCallbacks
+    def get_current_token(self):
+        events_key = yield self.sources[0].get_current_token_part()
+        token = EventSources.create_token(events_key, "0")
+        defer.returnValue(token)
+
+
+class StreamSource(object):
+    def get_keys_for_user(self, user):
+        raise NotImplementedError("get_keys_for_user")
+
+    def get_new_events_for_user(self, user, from_token, limit, key=None):
+        raise NotImplementedError("get_new_events_for_user")
+
+    def get_current_token_part(self):
+        raise NotImplementedError("get_current_token_part")
+
+
+class PaginationSource(object):
+    def get_pagination_rows(self, from_token, to_token, limit, key):
+        raise NotImplementedError("get_rows")
+