Merge pull request #2252 from matrix-org/erikj/user_dir

Add a user directory

1 files changed, 404 insertions, 0 deletions

diff --git a/synapse/handlers/user_directory.py b/synapse/handlers/user_directory.py
new file mode 100644
index 0000000000..d795a9f8d5
--- /dev/null
+++ b/synapse/handlers/user_directory.py
@@ -0,0 +1,404 @@
+# -*- 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.
+
+import logging
+
+from twisted.internet import defer
+
+from synapse.api.constants import EventTypes, JoinRules, Membership
+from synapse.storage.roommember import ProfileInfo
+from synapse.util.metrics import Measure
+
+
+logger = logging.getLogger(__name__)
+
+
+class UserDirectoyHandler(object):
+    """Handles querying of and keeping updated the user_directory.
+
+    N.B.: ASSUMES IT IS THE ONLY THING THAT MODIFIES THE USER DIRECTORY
+
+    The user directory is filled with users who this server can see are joined to a
+    world_readable or publically joinable room. We keep a database table up to date
+    by streaming changes of the current state and recalculating whether users should
+    be in the directory or not when necessary.
+
+    For each user in the directory we also store a room_id which is public and that the
+    user is joined to. This allows us to ignore history_visibility and join_rules changes
+    for that user in all other public rooms, as we know they'll still be in at least
+    one public room.
+    """
+
+    def __init__(self, hs):
+        self.store = hs.get_datastore()
+        self.state = hs.get_state_handler()
+        self.server_name = hs.hostname
+        self.clock = hs.get_clock()
+
+        # When start up for the first time we need to populate the user_directory.
+        # This is a set of user_id's we've inserted already
+        self.initially_handled_users = set()
+        self.initially_handled_users_in_public = set()
+
+        # The current position in the current_state_delta stream
+        self.pos = None
+
+        # Guard to ensure we only process deltas one at a time
+        self._is_processing = False
+
+        # We kick this off so that we don't have to wait for a change before
+        # we start populating the user directory
+        self.clock.call_later(0, self.notify_new_event)
+
+    def search_users(self, search_term, limit):
+        """Searches for users in directory
+
+        Returns:
+            dict of the form::
+
+                {
+                    "limited": <bool>,  # whether there were more results or not
+                    "results": [  # Ordered by best match first
+                        {
+                            "user_id": <user_id>,
+                            "display_name": <display_name>,
+                            "avatar_url": <avatar_url>
+                        }
+                    ]
+                }
+        """
+        return self.store.search_user_dir(search_term, limit)
+
+    @defer.inlineCallbacks
+    def notify_new_event(self):
+        """Called when there may be more deltas to process
+        """
+        if self._is_processing:
+            return
+
+        self._is_processing = True
+        try:
+            yield self._unsafe_process()
+        finally:
+            self._is_processing = False
+
+    @defer.inlineCallbacks
+    def _unsafe_process(self):
+        # If self.pos is None then means we haven't fetched it from DB
+        if self.pos is None:
+            self.pos = yield self.store.get_user_directory_stream_pos()
+
+        # If still None then we need to do the initial fill of directory
+        if self.pos is None:
+            yield self._do_initial_spam()
+            self.pos = yield self.store.get_user_directory_stream_pos()
+
+        # Loop round handling deltas until we're up to date
+        while True:
+            with Measure(self.clock, "user_dir_delta"):
+                deltas = yield self.store.get_current_state_deltas(self.pos)
+                if not deltas:
+                    return
+
+                yield self._handle_deltas(deltas)
+
+                self.pos = deltas[-1]["stream_id"]
+                yield self.store.update_user_directory_stream_pos(self.pos)
+
+    @defer.inlineCallbacks
+    def _do_initial_spam(self):
+        """Populates the user_directory from the current state of the DB, used
+        when synapse first starts with user_directory support
+        """
+        new_pos = yield self.store.get_max_stream_id_in_current_state_deltas()
+
+        # Delete any existing entries just in case there are any
+        yield self.store.delete_all_from_user_dir()
+
+        # We process by going through each existing room at a time.
+        room_ids = yield self.store.get_all_rooms()
+
+        for room_id in room_ids:
+            yield self._handle_intial_room(room_id)
+
+        self.initially_handled_users = None
+
+        yield self.store.update_user_directory_stream_pos(new_pos)
+
+    @defer.inlineCallbacks
+    def _handle_intial_room(self, room_id):
+        """Called when we initially fill out user_directory one room at a time
+        """
+        is_in_room = yield self.state.get_is_host_in_room(room_id, self.server_name)
+        if not is_in_room:
+            return
+
+        is_public = yield self.store.is_room_world_readable_or_publicly_joinable(room_id)
+
+        users_with_profile = yield self.state.get_current_user_in_room(room_id)
+        unhandled_users = set(users_with_profile) - self.initially_handled_users
+
+        yield self.store.add_profiles_to_user_dir(
+            room_id, {
+                user_id: users_with_profile[user_id] for user_id in unhandled_users
+            }
+        )
+
+        self.initially_handled_users |= unhandled_users
+
+        if is_public:
+            yield self.store.add_users_to_public_room(
+                room_id,
+                user_ids=unhandled_users - self.initially_handled_users_in_public
+            )
+            self.initially_handled_users_in_public != unhandled_users
+
+    @defer.inlineCallbacks
+    def _handle_deltas(self, deltas):
+        """Called with the state deltas to process
+        """
+        for delta in deltas:
+            typ = delta["type"]
+            state_key = delta["state_key"]
+            room_id = delta["room_id"]
+            event_id = delta["event_id"]
+            prev_event_id = delta["prev_event_id"]
+
+            logger.debug("Handling: %r %r, %s", typ, state_key, event_id)
+
+            # For join rule and visibility changes we need to check if the room
+            # may have become public or not and add/remove the users in said room
+            if typ in (EventTypes.RoomHistoryVisibility, EventTypes.JoinRules):
+                yield self._handle_room_publicity_change(
+                    room_id, prev_event_id, event_id, typ,
+                )
+            elif typ == EventTypes.Member:
+                change = yield self._get_key_change(
+                    prev_event_id, event_id,
+                    key_name="membership",
+                    public_value=Membership.JOIN,
+                )
+
+                if change is None:
+                    continue
+
+                if not change:
+                    # Need to check if the server left the room entirely, if so
+                    # we might need to remove all the users in that room
+                    is_in_room = yield self.state.get_is_host_in_room(
+                        room_id, self.server_name,
+                    )
+                    if not is_in_room:
+                        logger.debug("Server left room: %r", room_id)
+                        # Fetch all the users that we marked as being in user
+                        # directory due to being in the room and then check if
+                        # need to remove those users or not
+                        user_ids = yield self.store.get_users_in_dir_due_to_room(room_id)
+                        for user_id in user_ids:
+                            yield self._handle_remove_user(room_id, user_id)
+                        return
+                    else:
+                        logger.debug("Server is still in room: %r", room_id)
+
+                if change:  # The user joined
+                    event = yield self.store.get_event(event_id)
+                    profile = ProfileInfo(
+                        avatar_url=event.content.get("avatar_url"),
+                        display_name=event.content.get("displayname"),
+                    )
+
+                    yield self._handle_new_user(room_id, state_key, profile)
+                else:  # The user left
+                    yield self._handle_remove_user(room_id, state_key)
+            else:
+                logger.debug("Ignoring irrelevant type: %r", typ)
+
+    @defer.inlineCallbacks
+    def _handle_room_publicity_change(self, room_id, prev_event_id, event_id, typ):
+        """Handle a room having potentially changed from/to world_readable/publically
+        joinable.
+
+        Args:
+            room_id (str)
+            prev_event_id (str|None): The previous event before the state change
+            event_id (str|None): The new event after the state change
+            typ (str): Type of the event
+        """
+        logger.debug("Handling change for %s", typ)
+
+        if typ == EventTypes.RoomHistoryVisibility:
+            change = yield self._get_key_change(
+                prev_event_id, event_id,
+                key_name="history_visibility",
+                public_value="world_readable",
+            )
+        elif typ == EventTypes.JoinRules:
+            change = yield self._get_key_change(
+                prev_event_id, event_id,
+                key_name="join_rule",
+                public_value=JoinRules.PUBLIC,
+            )
+        else:
+            raise Exception("Invalid event type")
+        # If change is None, no change. True => become world_readable/public,
+        # False => was world_readable/public
+        if change is None:
+            logger.debug("No change")
+            return
+
+        # There's been a change to or from being world readable.
+
+        is_public = yield self.store.is_room_world_readable_or_publicly_joinable(
+            room_id
+        )
+
+        logger.debug("Change: %r, is_public: %r", change, is_public)
+
+        if change and not is_public:
+            # If we became world readable but room isn't currently public then
+            # we ignore the change
+            return
+        elif not change and is_public:
+            # If we stopped being world readable but are still public,
+            # ignore the change
+            return
+
+        if change:
+            users_with_profile = yield self.state.get_current_user_in_room(room_id)
+            for user_id, profile in users_with_profile.iteritems():
+                yield self._handle_new_user(room_id, user_id, profile)
+        else:
+            users = yield self.store.get_users_in_public_due_to_room(room_id)
+            for user_id in users:
+                yield self._handle_remove_user(room_id, user_id)
+
+    @defer.inlineCallbacks
+    def _handle_new_user(self, room_id, user_id, profile):
+        """Called when we might need to add user to directory
+
+        Args:
+            room_id (str): room_id that user joined or started being public that
+            user_id (str)
+        """
+        logger.debug("Adding user to dir, %r", user_id)
+
+        row = yield self.store.get_user_in_directory(user_id)
+        if not row:
+            yield self.store.add_profiles_to_user_dir(room_id, {user_id: profile})
+
+        is_public = yield self.store.is_room_world_readable_or_publicly_joinable(
+            room_id
+        )
+
+        if not is_public:
+            return
+
+        row = yield self.store.get_user_in_public_room(user_id)
+        if not row:
+            yield self.store.add_users_to_public_room(room_id, [user_id])
+
+    @defer.inlineCallbacks
+    def _handle_remove_user(self, room_id, user_id):
+        """Called when we might need to remove user to directory
+
+        Args:
+            room_id (str): room_id that user left or stopped being public that
+            user_id (str)
+        """
+        logger.debug("Maybe removing user %r", user_id)
+
+        row = yield self.store.get_user_in_directory(user_id)
+        update_user_dir = row and row["room_id"] == room_id
+
+        row = yield self.store.get_user_in_public_room(user_id)
+        update_user_in_public = row and row["room_id"] == room_id
+
+        if not update_user_in_public and not update_user_dir:
+            return
+
+        # XXX: Make this faster?
+        rooms = yield self.store.get_rooms_for_user(user_id)
+        for j_room_id in rooms:
+            if not update_user_in_public and not update_user_dir:
+                break
+
+            is_in_room = yield self.state.get_is_host_in_room(
+                j_room_id, self.server_name,
+            )
+
+            if not is_in_room:
+                continue
+
+            if update_user_dir:
+                update_user_dir = False
+                yield self.store.update_user_in_user_dir(user_id, j_room_id)
+
+            if update_user_in_public:
+                is_public = yield self.store.is_room_world_readable_or_publicly_joinable(
+                    j_room_id
+                )
+
+                if is_public:
+                    yield self.store.update_user_in_public_user_list(user_id, j_room_id)
+                    update_user_in_public = False
+
+        if update_user_dir:
+            yield self.store.remove_from_user_dir(user_id)
+        elif update_user_in_public:
+            yield self.store.remove_from_user_in_public_room(user_id)
+
+    @defer.inlineCallbacks
+    def _get_key_change(self, prev_event_id, event_id, key_name, public_value):
+        """Given two events check if the `key_name` field in content changed
+        from not matching `public_value` to doing so.
+
+        For example, check if `history_visibility` (`key_name`) changed from
+        `shared` to `world_readable` (`public_value`).
+
+        Returns:
+            None if the field in the events either both match `public_value`
+            or if neither do, i.e. there has been no change.
+            True if it didnt match `public_value` but now does
+            False if it did match `public_value` but now doesn't
+        """
+        prev_event = None
+        event = None
+        if prev_event_id:
+            prev_event = yield self.store.get_event(prev_event_id, allow_none=True)
+
+        if event_id:
+            event = yield self.store.get_event(event_id, allow_none=True)
+
+        if not event and not prev_event:
+            logger.debug("Neither event exists: %r %r", prev_event_id, event_id)
+            defer.returnValue(None)
+
+        prev_value = None
+        value = None
+
+        if prev_event:
+            prev_value = prev_event.content.get(key_name)
+
+        if event:
+            value = event.content.get(key_name)
+
+        logger.debug("prev_value: %r -> value: %r", prev_value, value)
+
+        if value == public_value and prev_value != public_value:
+            defer.returnValue(True)
+        elif value != public_value and prev_value == public_value:
+            defer.returnValue(False)
+        else:
+            defer.returnValue(None)