Merge pull request #2120 from matrix-org/luke/read-markers

Implement Read Marker API

6 files changed, 167 insertions, 1 deletions

diff --git a/synapse/handlers/read_marker.py b/synapse/handlers/read_marker.py
new file mode 100644
index 0000000000..3f46a16b90
--- /dev/null
+++ b/synapse/handlers/read_marker.py
@@ -0,0 +1,64 @@
+# -*- coding: utf-8 -*-
+# Copyright 2017 Vector Creations 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 ._base import BaseHandler
+
+from twisted.internet import defer
+
+from synapse.util.async import Linearizer
+
+import logging
+logger = logging.getLogger(__name__)
+
+
+class ReadMarkerHandler(BaseHandler):
+    def __init__(self, hs):
+        super(ReadMarkerHandler, self).__init__(hs)
+        self.server_name = hs.config.server_name
+        self.store = hs.get_datastore()
+        self.read_marker_linearizer = Linearizer(name="read_marker")
+        self.notifier = hs.get_notifier()
+
+    @defer.inlineCallbacks
+    def received_client_read_marker(self, room_id, user_id, event_id):
+        """Updates the read marker for a given user in a given room if the event ID given
+        is ahead in the stream relative to the current read marker.
+
+        This uses a notifier to indicate that account data should be sent down /sync if
+        the read marker has changed.
+        """
+
+        with (yield self.read_marker_linearizer.queue((room_id, user_id))):
+            account_data = yield self.store.get_account_data_for_room(user_id, room_id)
+
+            existing_read_marker = account_data.get("m.read_marker", None)
+
+            should_update = True
+
+            if existing_read_marker:
+                # Only update if the new marker is ahead in the stream
+                should_update = yield self.store.is_event_after(
+                    event_id,
+                    existing_read_marker['marker']
+                )
+
+            if should_update:
+                content = {
+                    "marker": event_id
+                }
+                max_id = yield self.store.add_account_data_to_room(
+                    user_id, room_id, "m.read_marker", content
+                )
+                self.notifier.on_new_event("account_data_key", max_id, users=[user_id])
diff --git a/synapse/rest/__init__.py b/synapse/rest/__init__.py
index f9f5a3e077..aa8d874f96 100644
--- a/synapse/rest/__init__.py
+++ b/synapse/rest/__init__.py
@@ -40,6 +40,7 @@ from synapse.rest.client.v2_alpha import (
     register,
     auth,
     receipts,
+    read_marker,
     keys,
     tokenrefresh,
     tags,
@@ -88,6 +89,7 @@ class ClientRestResource(JsonResource):
         register.register_servlets(hs, client_resource)
         auth.register_servlets(hs, client_resource)
         receipts.register_servlets(hs, client_resource)
+        read_marker.register_servlets(hs, client_resource)
         keys.register_servlets(hs, client_resource)
         tokenrefresh.register_servlets(hs, client_resource)
         tags.register_servlets(hs, client_resource)
diff --git a/synapse/rest/client/v2_alpha/account_data.py b/synapse/rest/client/v2_alpha/account_data.py
index b16079cece..1f9f42e661 100644
--- a/synapse/rest/client/v2_alpha/account_data.py
+++ b/synapse/rest/client/v2_alpha/account_data.py
@@ -16,7 +16,7 @@
 from ._base import client_v2_patterns
 
 from synapse.http.servlet import RestServlet, parse_json_object_from_request
-from synapse.api.errors import AuthError
+from synapse.api.errors import AuthError, SynapseError
 
 from twisted.internet import defer
 
@@ -82,6 +82,13 @@ class RoomAccountDataServlet(RestServlet):
 
         body = parse_json_object_from_request(request)
 
+        if account_data_type == "m.read_marker":
+            raise SynapseError(
+                405,
+                "Cannot set m.read_marker through this API."
+                " Use /rooms/!roomId:server.name/read_marker"
+            )
+
         max_id = yield self.store.add_account_data_to_room(
             user_id, room_id, account_data_type, body
         )
diff --git a/synapse/rest/client/v2_alpha/read_marker.py b/synapse/rest/client/v2_alpha/read_marker.py
new file mode 100644
index 0000000000..95e8e39974
--- /dev/null
+++ b/synapse/rest/client/v2_alpha/read_marker.py
@@ -0,0 +1,66 @@
+# -*- coding: utf-8 -*-
+# Copyright 2017 Vector Creations 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 import defer
+
+from synapse.http.servlet import RestServlet, parse_json_object_from_request
+from ._base import client_v2_patterns
+
+import logging
+
+
+logger = logging.getLogger(__name__)
+
+
+class ReadMarkerRestServlet(RestServlet):
+    PATTERNS = client_v2_patterns("/rooms/(?P<room_id>[^/]*)/read_marker$")
+
+    def __init__(self, hs):
+        super(ReadMarkerRestServlet, self).__init__()
+        self.auth = hs.get_auth()
+        self.receipts_handler = hs.get_receipts_handler()
+        self.read_marker_handler = hs.get_read_marker_handler()
+        self.presence_handler = hs.get_presence_handler()
+
+    @defer.inlineCallbacks
+    def on_POST(self, request, room_id):
+        requester = yield self.auth.get_user_by_req(request)
+
+        yield self.presence_handler.bump_presence_active_time(requester.user)
+
+        body = parse_json_object_from_request(request)
+
+        read_event_id = body.get("m.read", None)
+        if read_event_id:
+            yield self.receipts_handler.received_client_receipt(
+                room_id,
+                "m.read",
+                user_id=requester.user.to_string(),
+                event_id=read_event_id
+            )
+
+        read_marker_event_id = body.get("m.read_marker", None)
+        if read_marker_event_id:
+            yield self.read_marker_handler.received_client_read_marker(
+                room_id,
+                user_id=requester.user.to_string(),
+                event_id=read_marker_event_id
+            )
+
+        defer.returnValue((200, {}))
+
+
+def register_servlets(hs, http_server):
+    ReadMarkerRestServlet(hs).register(http_server)
diff --git a/synapse/server.py b/synapse/server.py
index 6310152560..12754c89ae 100644
--- a/synapse/server.py
+++ b/synapse/server.py
@@ -48,6 +48,7 @@ from synapse.handlers.typing import TypingHandler
 from synapse.handlers.events import EventHandler, EventStreamHandler
 from synapse.handlers.initial_sync import InitialSyncHandler
 from synapse.handlers.receipts import ReceiptsHandler
+from synapse.handlers.read_marker import ReadMarkerHandler
 from synapse.http.client import SimpleHttpClient, InsecureInterceptableContextFactory
 from synapse.http.matrixfederationclient import MatrixFederationHttpClient
 from synapse.notifier import Notifier
@@ -133,6 +134,7 @@ class HomeServer(object):
         'receipts_handler',
         'macaroon_generator',
         'tcp_replication',
+        'read_marker_handler',
     ]
 
     def __init__(self, hostname, **kwargs):
@@ -291,6 +293,9 @@ class HomeServer(object):
     def build_receipts_handler(self):
         return ReceiptsHandler(self)
 
+    def build_read_marker_handler(self):
+        return ReadMarkerHandler(self)
+
     def build_tcp_replication(self):
         raise NotImplementedError()
 
diff --git a/synapse/storage/events.py b/synapse/storage/events.py
index 64fe937bdc..a3790419dd 100644
--- a/synapse/storage/events.py
+++ b/synapse/storage/events.py
@@ -2159,6 +2159,28 @@ class EventsStore(SQLBaseStore):
             ]
         )
 
+    @defer.inlineCallbacks
+    def is_event_after(self, event_id1, event_id2):
+        """Returns True if event_id1 is after event_id2 in the stream
+        """
+        to_1, so_1 = yield self._get_event_ordering(event_id1)
+        to_2, so_2 = yield self._get_event_ordering(event_id2)
+        defer.returnValue((to_1, so_1) > (to_2, so_2))
+
+    @defer.inlineCallbacks
+    def _get_event_ordering(self, event_id):
+        res = yield self._simple_select_one(
+            table="events",
+            retcols=["topological_ordering", "stream_ordering"],
+            keyvalues={"event_id": event_id},
+            allow_none=True
+        )
+
+        if not res:
+            raise SynapseError(404, "Could not find event %s" % (event_id,))
+
+        defer.returnValue((int(res["topological_ordering"]), int(res["stream_ordering"])))
+
 
 AllNewEventsResult = namedtuple("AllNewEventsResult", [
     "new_forward_events", "new_backfill_events",