Merge pull request #4091 from matrix-org/rav/room_version_upgrades

Room version upgrade support

9 files changed, 325 insertions, 47 deletions

diff --git a/changelog.d/4091.feature b/changelog.d/4091.feature
new file mode 100644
index 0000000000..a3f7dbdcdd
--- /dev/null
+++ b/changelog.d/4091.feature
@@ -0,0 +1 @@
+Support for replacing rooms with new ones
diff --git a/synapse/api/constants.py b/synapse/api/constants.py
index c2630c4c64..5565e516d6 100644
--- a/synapse/api/constants.py
+++ b/synapse/api/constants.py
@@ -61,6 +61,7 @@ class LoginType(object):
 class EventTypes(object):
     Member = "m.room.member"
     Create = "m.room.create"
+    Tombstone = "m.room.tombstone"
     JoinRules = "m.room.join_rules"
     PowerLevels = "m.room.power_levels"
     Aliases = "m.room.aliases"
diff --git a/synapse/handlers/register.py b/synapse/handlers/register.py
index e9d7b25a36..7b4549223f 100644
--- a/synapse/handlers/register.py
+++ b/synapse/handlers/register.py
@@ -50,7 +50,6 @@ class RegistrationHandler(BaseHandler):
         self._auth_handler = hs.get_auth_handler()
         self.profile_handler = hs.get_profile_handler()
         self.user_directory_handler = hs.get_user_directory_handler()
-        self.room_creation_handler = self.hs.get_room_creation_handler()
         self.captcha_client = CaptchaServerHttpClient(hs)
 
         self._next_generated_user_id = None
@@ -241,7 +240,10 @@ class RegistrationHandler(BaseHandler):
                     else:
                         # create room expects the localpart of the room alias
                         room_alias_localpart = room_alias.localpart
-                        yield self.room_creation_handler.create_room(
+
+                        # getting the RoomCreationHandler during init gives a dependency
+                        # loop
+                        yield self.hs.get_room_creation_handler().create_room(
                             fake_requester,
                             config={
                                 "preset": "public_chat",
diff --git a/synapse/handlers/room.py b/synapse/handlers/room.py
index 3ba92bdb4c..8e48c1ca6a 100644
--- a/synapse/handlers/room.py
+++ b/synapse/handlers/room.py
@@ -21,7 +21,7 @@ import math
 import string
 from collections import OrderedDict
 
-from six import string_types
+from six import iteritems, string_types
 
 from twisted.internet import defer
 
@@ -32,10 +32,11 @@ from synapse.api.constants import (
     JoinRules,
     RoomCreationPreset,
 )
-from synapse.api.errors import AuthError, Codes, StoreError, SynapseError
+from synapse.api.errors import AuthError, Codes, NotFoundError, StoreError, SynapseError
 from synapse.storage.state import StateFilter
 from synapse.types import RoomAlias, RoomID, RoomStreamToken, StreamToken, UserID
 from synapse.util import stringutils
+from synapse.util.async_helpers import Linearizer
 from synapse.visibility import filter_events_for_client
 
 from ._base import BaseHandler
@@ -73,6 +74,190 @@ class RoomCreationHandler(BaseHandler):
 
         self.spam_checker = hs.get_spam_checker()
         self.event_creation_handler = hs.get_event_creation_handler()
+        self.room_member_handler = hs.get_room_member_handler()
+
+        # linearizer to stop two upgrades happening at once
+        self._upgrade_linearizer = Linearizer("room_upgrade_linearizer")
+
+    @defer.inlineCallbacks
+    def upgrade_room(self, requester, old_room_id, new_version):
+        """Replace a room with a new room with a different version
+
+        Args:
+            requester (synapse.types.Requester): the user requesting the upgrade
+            old_room_id (unicode): the id of the room to be replaced
+            new_version (unicode): the new room version to use
+
+        Returns:
+            Deferred[unicode]: the new room id
+        """
+        yield self.ratelimit(requester)
+
+        user_id = requester.user.to_string()
+
+        with (yield self._upgrade_linearizer.queue(old_room_id)):
+            # start by allocating a new room id
+            r = yield self.store.get_room(old_room_id)
+            if r is None:
+                raise NotFoundError("Unknown room id %s" % (old_room_id,))
+            new_room_id = yield self._generate_room_id(
+                creator_id=user_id, is_public=r["is_public"],
+            )
+
+            # we create and auth the tombstone event before properly creating the new
+            # room, to check our user has perms in the old room.
+            tombstone_event, tombstone_context = (
+                yield self.event_creation_handler.create_event(
+                    requester, {
+                        "type": EventTypes.Tombstone,
+                        "state_key": "",
+                        "room_id": old_room_id,
+                        "sender": user_id,
+                        "content": {
+                            "body": "This room has been replaced",
+                            "replacement_room": new_room_id,
+                        }
+                    },
+                    token_id=requester.access_token_id,
+                )
+            )
+            yield self.auth.check_from_context(tombstone_event, tombstone_context)
+
+            yield self.clone_exiting_room(
+                requester,
+                old_room_id=old_room_id,
+                new_room_id=new_room_id,
+                new_room_version=new_version,
+                tombstone_event_id=tombstone_event.event_id,
+            )
+
+            # now send the tombstone
+            yield self.event_creation_handler.send_nonmember_event(
+                requester, tombstone_event, tombstone_context,
+            )
+
+            old_room_state = yield tombstone_context.get_current_state_ids(self.store)
+            old_room_pl_event_id = old_room_state.get((EventTypes.PowerLevels, ""))
+
+            if old_room_pl_event_id is None:
+                logger.warning(
+                    "Not supported: upgrading a room with no PL event. Not setting PLs "
+                    "in old room.",
+                )
+            else:
+                # we try to stop regular users from speaking by setting the PL required
+                # to send regular events and invites to 'Moderator' level. That's normally
+                # 50, but if the default PL in a room is 50 or more, then we set the
+                # required PL above that.
+
+                old_room_pl_state = yield self.store.get_event(old_room_pl_event_id)
+                pl_content = dict(old_room_pl_state.content)
+                users_default = int(pl_content.get("users_default", 0))
+                restricted_level = max(users_default + 1, 50)
+
+                updated = False
+                for v in ("invite", "events_default"):
+                    current = int(pl_content.get(v, 0))
+                    if current < restricted_level:
+                        logger.debug(
+                            "Setting level for %s in %s to %i (was %i)",
+                            v, old_room_id, restricted_level, current,
+                        )
+                        pl_content[v] = restricted_level
+                        updated = True
+                    else:
+                        logger.debug(
+                            "Not setting level for %s (already %i)",
+                            v, current,
+                        )
+
+                if updated:
+                    yield self.event_creation_handler.create_and_send_nonmember_event(
+                        requester, {
+                            "type": EventTypes.PowerLevels,
+                            "state_key": '',
+                            "room_id": old_room_id,
+                            "sender": user_id,
+                            "content": pl_content,
+                        }, ratelimit=False,
+                    )
+
+        defer.returnValue(new_room_id)
+
+    @defer.inlineCallbacks
+    def clone_exiting_room(
+            self, requester, old_room_id, new_room_id, new_room_version,
+            tombstone_event_id,
+    ):
+        """Populate a new room based on an old room
+
+        Args:
+            requester (synapse.types.Requester): the user requesting the upgrade
+            old_room_id (unicode): the id of the room to be replaced
+            new_room_id (unicode): the id to give the new room (should already have been
+                created with _gemerate_room_id())
+            new_room_version (unicode): the new room version to use
+            tombstone_event_id (unicode|str): the ID of the tombstone event in the old
+                room.
+        Returns:
+            Deferred[None]
+        """
+        user_id = requester.user.to_string()
+
+        if not self.spam_checker.user_may_create_room(user_id):
+            raise SynapseError(403, "You are not permitted to create rooms")
+
+        # XXX check alias is free
+        # canonical_alias = None
+
+        # XXX create association in directory handler
+
+        creation_content = {
+            "room_version": new_room_version,
+            "predecessor": {
+                "room_id": old_room_id,
+                "event_id": tombstone_event_id,
+            }
+        }
+
+        initial_state = dict()
+
+        types_to_copy = (
+            (EventTypes.PowerLevels, ""),
+            (EventTypes.JoinRules, ""),
+            (EventTypes.Name, ""),
+            (EventTypes.Topic, ""),
+            (EventTypes.RoomHistoryVisibility, ""),
+            (EventTypes.GuestAccess, "")
+        )
+
+        old_room_state_ids = yield self.store.get_filtered_current_state_ids(
+            old_room_id, StateFilter.from_types(types_to_copy),
+        )
+        # map from event_id to BaseEvent
+        old_room_state_events = yield self.store.get_events(old_room_state_ids.values())
+
+        for k, old_event_id in iteritems(old_room_state_ids):
+            old_event = old_room_state_events.get(old_event_id)
+            if old_event:
+                initial_state[k] = old_event.content
+
+        yield self._send_events_for_new_room(
+            requester,
+            new_room_id,
+
+            # we expect to override all the presets with initial_state, so this is
+            # somewhat arbitrary.
+            preset_config=RoomCreationPreset.PRIVATE_CHAT,
+
+            invite_list=[],
+            initial_state=initial_state,
+            creation_content=creation_content,
+        )
+
+        # XXX invites/joins
+        # XXX 3pid invites
+        # XXX directory_handler.send_room_alias_update_event
 
     @defer.inlineCallbacks
     def create_room(self, requester, config, ratelimit=True,
@@ -165,28 +350,7 @@ class RoomCreationHandler(BaseHandler):
         visibility = config.get("visibility", None)
         is_public = visibility == "public"
 
-        # autogen room IDs and try to create it. We may clash, so just
-        # try a few times till one goes through, giving up eventually.
-        attempts = 0
-        room_id = None
-        while attempts < 5:
-            try:
-                random_string = stringutils.random_string(18)
-                gen_room_id = RoomID(
-                    random_string,
-                    self.hs.hostname,
-                )
-                yield self.store.store_room(
-                    room_id=gen_room_id.to_string(),
-                    room_creator_user_id=user_id,
-                    is_public=is_public
-                )
-                room_id = gen_room_id.to_string()
-                break
-            except StoreError:
-                attempts += 1
-        if not room_id:
-            raise StoreError(500, "Couldn't generate a room ID.")
+        room_id = yield self._generate_room_id(creator_id=user_id, is_public=is_public)
 
         if room_alias:
             directory_handler = self.hs.get_handlers().directory_handler
@@ -216,18 +380,15 @@ class RoomCreationHandler(BaseHandler):
         # override any attempt to set room versions via the creation_content
         creation_content["room_version"] = room_version
 
-        room_member_handler = self.hs.get_room_member_handler()
-
         yield self._send_events_for_new_room(
             requester,
             room_id,
-            room_member_handler,
             preset_config=preset_config,
             invite_list=invite_list,
             initial_state=initial_state,
             creation_content=creation_content,
             room_alias=room_alias,
-            power_level_content_override=config.get("power_level_content_override", {}),
+            power_level_content_override=config.get("power_level_content_override"),
             creator_join_profile=creator_join_profile,
         )
 
@@ -263,7 +424,7 @@ class RoomCreationHandler(BaseHandler):
             if is_direct:
                 content["is_direct"] = is_direct
 
-            yield room_member_handler.update_membership(
+            yield self.room_member_handler.update_membership(
                 requester,
                 UserID.from_string(invitee),
                 room_id,
@@ -301,14 +462,13 @@ class RoomCreationHandler(BaseHandler):
             self,
             creator,  # A Requester object.
             room_id,
-            room_member_handler,
             preset_config,
             invite_list,
             initial_state,
             creation_content,
-            room_alias,
-            power_level_content_override,
-            creator_join_profile,
+            room_alias=None,
+            power_level_content_override=None,
+            creator_join_profile=None,
     ):
         def create(etype, content, **kwargs):
             e = {
@@ -346,7 +506,7 @@ class RoomCreationHandler(BaseHandler):
             content=creation_content,
         )
 
-        yield room_member_handler.update_membership(
+        yield self.room_member_handler.update_membership(
             creator,
             creator.user,
             room_id,
@@ -388,7 +548,8 @@ class RoomCreationHandler(BaseHandler):
                 for invitee in invite_list:
                     power_level_content["users"][invitee] = 100
 
-            power_level_content.update(power_level_content_override)
+            if power_level_content_override:
+                power_level_content.update(power_level_content_override)
 
             yield send(
                 etype=EventTypes.PowerLevels,
@@ -427,6 +588,30 @@ class RoomCreationHandler(BaseHandler):
                 content=content,
             )
 
+    @defer.inlineCallbacks
+    def _generate_room_id(self, creator_id, is_public):
+        # autogen room IDs and try to create it. We may clash, so just
+        # try a few times till one goes through, giving up eventually.
+        attempts = 0
+        while attempts < 5:
+            try:
+                random_string = stringutils.random_string(18)
+                gen_room_id = RoomID(
+                    random_string,
+                    self.hs.hostname,
+                ).to_string()
+                if isinstance(gen_room_id, bytes):
+                    gen_room_id = gen_room_id.decode('utf-8')
+                yield self.store.store_room(
+                    room_id=gen_room_id,
+                    room_creator_user_id=creator_id,
+                    is_public=is_public,
+                )
+                defer.returnValue(gen_room_id)
+            except StoreError:
+                attempts += 1
+        raise StoreError(500, "Couldn't generate a room ID.")
+
 
 class RoomContextHandler(object):
     def __init__(self, hs):
diff --git a/synapse/rest/__init__.py b/synapse/rest/__init__.py
index 4856822a5d..5f35c2d1be 100644
--- a/synapse/rest/__init__.py
+++ b/synapse/rest/__init__.py
@@ -47,6 +47,7 @@ from synapse.rest.client.v2_alpha import (
     register,
     report_event,
     room_keys,
+    room_upgrade_rest_servlet,
     sendtodevice,
     sync,
     tags,
@@ -116,3 +117,4 @@ class ClientRestResource(JsonResource):
         sendtodevice.register_servlets(hs, client_resource)
         user_directory.register_servlets(hs, client_resource)
         groups.register_servlets(hs, client_resource)
+        room_upgrade_rest_servlet.register_servlets(hs, client_resource)
diff --git a/synapse/rest/client/v2_alpha/room_upgrade_rest_servlet.py b/synapse/rest/client/v2_alpha/room_upgrade_rest_servlet.py
new file mode 100644
index 0000000000..e6356101fd
--- /dev/null
+++ b/synapse/rest/client/v2_alpha/room_upgrade_rest_servlet.py
@@ -0,0 +1,89 @@
+# -*- coding: utf-8 -*-
+# Copyright 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.
+
+import logging
+
+from twisted.internet import defer
+
+from synapse.api.constants import KNOWN_ROOM_VERSIONS
+from synapse.api.errors import Codes, SynapseError
+from synapse.http.servlet import (
+    RestServlet,
+    assert_params_in_dict,
+    parse_json_object_from_request,
+)
+
+from ._base import client_v2_patterns
+
+logger = logging.getLogger(__name__)
+
+
+class RoomUpgradeRestServlet(RestServlet):
+    """Handler for room uprade requests.
+
+    Handles requests of the form:
+
+        POST /_matrix/client/r0/rooms/$roomid/upgrade HTTP/1.1
+        Content-Type: application/json
+
+        {
+            "new_version": "2",
+        }
+
+    Creates a new room and shuts down the old one. Returns the ID of the new room.
+
+    Args:
+        hs (synapse.server.HomeServer):
+    """
+    PATTERNS = client_v2_patterns(
+        # /rooms/$roomid/upgrade
+        "/rooms/(?P<room_id>[^/]*)/upgrade$",
+        v2_alpha=False,
+    )
+
+    def __init__(self, hs):
+        super(RoomUpgradeRestServlet, self).__init__()
+        self._hs = hs
+        self._room_creation_handler = hs.get_room_creation_handler()
+        self._auth = hs.get_auth()
+
+    @defer.inlineCallbacks
+    def on_POST(self, request, room_id):
+        requester = yield self._auth.get_user_by_req(request)
+
+        content = parse_json_object_from_request(request)
+        assert_params_in_dict(content, ("new_version", ))
+        new_version = content["new_version"]
+
+        if new_version not in KNOWN_ROOM_VERSIONS:
+            raise SynapseError(
+                400,
+                "Your homeserver does not support this room version",
+                Codes.UNSUPPORTED_ROOM_VERSION,
+            )
+
+        new_room_id = yield self._room_creation_handler.upgrade_room(
+            requester, room_id, new_version
+        )
+
+        ret = {
+            "replacement_room": new_room_id,
+        }
+
+        defer.returnValue((200, ret))
+
+
+def register_servlets(hs, http_server):
+    RoomUpgradeRestServlet(hs).register(http_server)
diff --git a/synapse/server.pyi b/synapse/server.pyi
index ce28486233..06cd083a74 100644
--- a/synapse/server.pyi
+++ b/synapse/server.pyi
@@ -7,6 +7,9 @@ import synapse.handlers.auth
 import synapse.handlers.deactivate_account
 import synapse.handlers.device
 import synapse.handlers.e2e_keys
+import synapse.handlers.room
+import synapse.handlers.room_member
+import synapse.handlers.message
 import synapse.handlers.set_password
 import synapse.rest.media.v1.media_repository
 import synapse.server_notices.server_notices_manager
@@ -50,6 +53,9 @@ class HomeServer(object):
     def get_room_creation_handler(self) -> synapse.handlers.room.RoomCreationHandler:
         pass
 
+    def get_room_member_handler(self) -> synapse.handlers.room_member.RoomMemberHandler:
+        pass
+
     def get_event_creation_handler(self) -> synapse.handlers.message.EventCreationHandler:
         pass
 
diff --git a/synapse/storage/room.py b/synapse/storage/room.py
index 61013b8919..41c65e112a 100644
--- a/synapse/storage/room.py
+++ b/synapse/storage/room.py
@@ -47,7 +47,7 @@ class RoomWorkerStore(SQLBaseStore):
         Args:
             room_id (str): The ID of the room to retrieve.
         Returns:
-            A namedtuple containing the room information, or an empty list.
+            A dict containing the room information, or None if the room is unknown.
         """
         return self._simple_select_one(
             table="rooms",
diff --git a/tests/server_notices/test_resource_limits_server_notices.py b/tests/server_notices/test_resource_limits_server_notices.py
index 4701eedd45..b1551df7ca 100644
--- a/tests/server_notices/test_resource_limits_server_notices.py
+++ b/tests/server_notices/test_resource_limits_server_notices.py
@@ -4,7 +4,6 @@ from twisted.internet import defer
 
 from synapse.api.constants import EventTypes, ServerNoticeMsgType
 from synapse.api.errors import ResourceLimitError
-from synapse.handlers.auth import AuthHandler
 from synapse.server_notices.resource_limits_server_notices import (
     ResourceLimitsServerNotices,
 )
@@ -13,17 +12,10 @@ from tests import unittest
 from tests.utils import setup_test_homeserver
 
 
-class AuthHandlers(object):
-    def __init__(self, hs):
-        self.auth_handler = AuthHandler(hs)
-
-
 class TestResourceLimitsServerNotices(unittest.TestCase):
     @defer.inlineCallbacks
     def setUp(self):
-        self.hs = yield setup_test_homeserver(self.addCleanup, handlers=None)
-        self.hs.handlers = AuthHandlers(self.hs)
-        self.auth_handler = self.hs.handlers.auth_handler
+        self.hs = yield setup_test_homeserver(self.addCleanup)
         self.server_notices_sender = self.hs.get_server_notices_sender()
 
         # relying on [1] is far from ideal, but the only case where