synapse-product/synapse/handlers/user_directory.py

# -*- 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 six import iteritems, iterkeys

from twisted.internet import defer

import synapse.metrics
from synapse.api.constants import EventTypes, JoinRules, Membership
from synapse.metrics.background_process_metrics import run_as_background_process
from synapse.storage.roommember import ProfileInfo
from synapse.types import get_localpart_from_id
from synapse.util.metrics import Measure

logger = logging.getLogger(__name__)


class UserDirectoryHandler(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.
    """

    INITIAL_ROOM_SLEEP_MS = 50
    INITIAL_ROOM_SLEEP_COUNT = 100
    INITIAL_ROOM_BATCH_SIZE = 100
    INITIAL_USER_SLEEP_MS = 10

    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()
        self.notifier = hs.get_notifier()
        self.is_mine_id = hs.is_mine_id
        self.update_user_directory = hs.config.update_user_directory
        self.search_all_users = hs.config.user_directory_search_all_users

        # If we're a worker, don't sleep when doing the initial room work, as it
        # won't monopolise the master's CPU.
        if hs.config.worker_app:
            self.INITIAL_ROOM_SLEEP_MS = 0
            self.INITIAL_USER_SLEEP_MS = 0

        # 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()

        # 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

        if self.update_user_directory:
            self.notifier.add_replication_callback(self.notify_new_event)

            # 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, user_id, 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(user_id, search_term, limit)

    def notify_new_event(self):
        """Called when there may be more deltas to process
        """
        if not self.update_user_directory:
            return

        if self._is_processing:
            return

        @defer.inlineCallbacks
        def process():
            try:
                yield self._unsafe_process()
            finally:
                self._is_processing = False

        self._is_processing = True
        run_as_background_process("user_directory.notify_new_event", process)

    @defer.inlineCallbacks
    def handle_local_profile_change(self, user_id, profile):
        """Called to update index of our local user profiles when they change
        irrespective of any rooms the user may be in.
        """
        # FIXME(#3714): We should probably do this in the same worker as all
        # the other changes.
        is_support = yield self.store.is_support_user(user_id)
        # Support users are for diagnostics and should not appear in the user directory.
        if not is_support:
            yield self.store.update_profile_in_user_dir(
                user_id, profile.display_name, profile.avatar_url, None
            )

    @defer.inlineCallbacks
    def handle_user_deactivated(self, user_id):
        """Called when a user ID is deactivated
        """
        # FIXME(#3714): We should probably do this in the same worker as all
        # the other changes.
        yield self.store.remove_from_user_dir(user_id)

    @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

                logger.info("Handling %d state deltas", len(deltas))
                yield self._handle_deltas(deltas)

                self.pos = deltas[-1]["stream_id"]

                # Expose current event processing position to prometheus
                synapse.metrics.event_processing_positions.labels("user_dir").set(
                    self.pos
                )

                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()

        logger.info("Doing initial update of user directory. %d rooms", len(room_ids))
        num_processed_rooms = 0

        for room_id in room_ids:
            logger.info("Handling room %d/%d", num_processed_rooms + 1, len(room_ids))
            yield self._handle_initial_room(room_id)
            num_processed_rooms += 1
            yield self.clock.sleep(self.INITIAL_ROOM_SLEEP_MS / 1000.0)

        logger.info("Processed all rooms.")

        if self.search_all_users:
            num_processed_users = 0
            user_ids = yield self.store.get_all_local_users()
            logger.info(
                "Doing initial update of user directory. %d users", len(user_ids)
            )
            for user_id in user_ids:
                # We add profiles for all users even if they don't match the
                # include pattern, just in case we want to change it in future
                logger.info(
                    "Handling user %d/%d", num_processed_users + 1, len(user_ids)
                )
                yield self._handle_local_user(user_id)
                num_processed_users += 1
                yield self.clock.sleep(self.INITIAL_USER_SLEEP_MS / 1000.0)

            logger.info("Processed all users")

        self.initially_handled_users = None

        yield self.store.update_user_directory_stream_pos(new_pos)

    @defer.inlineCallbacks
    def _handle_initial_room(self, room_id):
        """
        Called when we initially fill out user_directory one room at a time
        """
        is_in_room = yield self.store.is_host_joined(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)
        user_ids = set(users_with_profile)
        unhandled_users = user_ids - self.initially_handled_users

        yield self.store.add_profiles_to_user_dir(
            {user_id: users_with_profile[user_id] for user_id in unhandled_users}
        )

        self.initially_handled_users |= unhandled_users

        # We now go and figure out the new users who share rooms with user entries
        # We sleep aggressively here as otherwise it can starve resources.
        # We also batch up inserts/updates, but try to avoid too many at once.
        to_insert = set()
        count = 0

        if is_public:
            for user_id in user_ids:
                if count % self.INITIAL_ROOM_SLEEP_COUNT == 0:
                    yield self.clock.sleep(self.INITIAL_ROOM_SLEEP_MS / 1000.0)

                if self.store.get_if_app_services_interested_in_user(user_id):
                    count += 1
                    continue

                to_insert.add(user_id)
                if len(to_insert) > self.INITIAL_ROOM_BATCH_SIZE:
                    yield self.store.add_users_in_public_rooms(room_id, to_insert)
                    to_insert.clear()

            if to_insert:
                yield self.store.add_users_in_public_rooms(room_id, to_insert)
                to_insert.clear()
        else:

            for user_id in user_ids:
                if count % self.INITIAL_ROOM_SLEEP_COUNT == 0:
                    yield self.clock.sleep(self.INITIAL_ROOM_SLEEP_MS / 1000.0)

                if not self.is_mine_id(user_id):
                    count += 1
                    continue

                if self.store.get_if_app_services_interested_in_user(user_id):
                    count += 1
                    continue

                for other_user_id in user_ids:
                    if user_id == other_user_id:
                        continue

                    if count % self.INITIAL_ROOM_SLEEP_COUNT == 0:
                        yield self.clock.sleep(self.INITIAL_ROOM_SLEEP_MS / 1000.0)
                    count += 1

                    user_set = (user_id, other_user_id)
                    to_insert.add(user_set)

                    if len(to_insert) > self.INITIAL_ROOM_BATCH_SIZE:
                        yield self.store.add_users_who_share_private_room(
                            room_id, not is_public, to_insert
                        )
                        to_insert.clear()

            if to_insert:
                yield self.store.add_users_who_share_private_room(room_id, to_insert)
                to_insert.clear()

    @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 False:
                    # 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.store.is_host_joined(
                        room_id, self.server_name
                    )
                    if not is_in_room:
                        logger.info("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)

                is_support = yield self.store.is_support_user(state_key)
                if not is_support:
                    if change is None:
                        # Handle any profile changes
                        yield self._handle_profile_change(
                            state_key, room_id, prev_event_id, event_id
                        )
                        continue

                    if change:  # The user joined
                        event = yield self.store.get_event(event_id, allow_none=True)
                        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: %s", typ, room_id)

        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

        users_with_profile = yield self.state.get_current_user_in_room(room_id)

        # Remove every user from the sharing tables for that room.
        for user_id in iterkeys(users_with_profile):
            yield self.store.remove_user_who_share_room(user_id, room_id)

        # Then, re-add them to the tables.
        # NOTE: this is not the most efficient method, as handle_new_user sets
        # up local_user -> other_user and other_user_whos_local -> local_user,
        # which when ran over an entire room, will result in the same values
        # being added multiple times. The batching upserts shouldn't make this
        # too bad, though.
        for user_id, profile in iteritems(users_with_profile):
            yield self._handle_new_user(room_id, user_id, profile)

    @defer.inlineCallbacks
    def _handle_local_user(self, user_id):
        """Adds a new local roomless user into the user_directory_search table.
        Used to populate up the user index when we have an
        user_directory_search_all_users specified.
        """
        logger.debug("Adding new local user to dir, %r", user_id)

        profile = yield self.store.get_profileinfo(get_localpart_from_id(user_id))

        row = yield self.store.get_user_in_directory(user_id)
        if not row:
            yield self.store.add_profiles_to_user_dir({user_id: profile})

    @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
            user_id (str)
        """
        logger.debug("Adding new 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({user_id: profile})

        is_public = yield self.store.is_room_world_readable_or_publicly_joinable(
            room_id
        )
        # Now we update users who share rooms with users.
        users_with_profile = yield self.state.get_current_user_in_room(room_id)

        if is_public:
            yield self.store.add_users_in_public_rooms(room_id, (user_id,))
        else:
            to_insert = set()

            # First, if they're our user then we need to update for every user
            if self.is_mine_id(user_id):

                is_appservice = self.store.get_if_app_services_interested_in_user(user_id)

                # We don't care about appservice users.
                if not is_appservice:
                    for other_user_id in users_with_profile:
                        if user_id == other_user_id:
                            continue

                        to_insert.add((user_id, other_user_id))

            # Next we need to update for every local user in the room
            for other_user_id in users_with_profile:
                if user_id == other_user_id:
                    continue

                is_appservice = self.store.get_if_app_services_interested_in_user(
                    other_user_id
                )
                if self.is_mine_id(other_user_id) and not is_appservice:
                    to_insert.add((other_user_id, user_id))

            if to_insert:
                yield self.store.add_users_who_share_private_room(room_id, to_insert)

    @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("Removing user %r", user_id)

        # Remove user from sharing tables
        yield self.store.remove_user_who_share_room(user_id, room_id)

        # Are they still in any rooms? If not, remove them entirely.
        rooms_user_is_in = yield self.store.get_rooms_user_is_in(user_id)

        if len(rooms_user_is_in) == 0:
            yield self.store.remove_from_user_dir(user_id)

    @defer.inlineCallbacks
    def _handle_profile_change(self, user_id, room_id, prev_event_id, event_id):
        """Check member event changes for any profile changes and update the
        database if there are.
        """
        if not prev_event_id or not event_id:
            return

        prev_event = yield self.store.get_event(prev_event_id, allow_none=True)
        event = yield self.store.get_event(event_id, allow_none=True)

        if not prev_event or not event:
            return

        if event.membership != Membership.JOIN:
            return

        prev_name = prev_event.content.get("displayname")
        new_name = event.content.get("displayname")

        prev_avatar = prev_event.content.get("avatar_url")
        new_avatar = event.content.get("avatar_url")

        if prev_name != new_name or prev_avatar != new_avatar:
            yield self.store.update_profile_in_user_dir(
                user_id, new_name, new_avatar, room_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)