MatrixSynapse/synapse/storage/roommember.py

# -*- coding: utf-8 -*-
# Copyright 2014, 2015 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.

from twisted.internet import defer

from collections import namedtuple

from ._base import SQLBaseStore
from synapse.util.caches.descriptors import cached, cachedInlineCallbacks

from synapse.api.constants import Membership
from synapse.types import UserID

import logging

logger = logging.getLogger(__name__)


RoomsForUser = namedtuple(
    "RoomsForUser",
    ("room_id", "sender", "membership", "event_id", "stream_ordering")
)


class RoomMemberStore(SQLBaseStore):

    def _store_room_members_txn(self, txn, events):
        """Store a room member in the database.
        """
        self._simple_insert_many_txn(
            txn,
            table="room_memberships",
            values=[
                {
                    "event_id": event.event_id,
                    "user_id": event.state_key,
                    "sender": event.user_id,
                    "room_id": event.room_id,
                    "membership": event.membership,
                }
                for event in events
            ]
        )

        for event in events:
            txn.call_after(self.get_rooms_for_user.invalidate, (event.state_key,))
            txn.call_after(self.get_joined_hosts_for_room.invalidate, (event.room_id,))
            txn.call_after(self.get_users_in_room.invalidate, (event.room_id,))

    def get_room_member(self, user_id, room_id):
        """Retrieve the current state of a room member.

        Args:
            user_id (str): The member's user ID.
            room_id (str): The room the member is in.
        Returns:
            Deferred: Results in a MembershipEvent or None.
        """
        return self.runInteraction(
            "get_room_member",
            self._get_members_events_txn,
            room_id,
            user_id=user_id,
        ).addCallback(
            self._get_events
        ).addCallback(
            lambda events: events[0] if events else None
        )

    @cached(max_entries=5000)
    def get_users_in_room(self, room_id):
        def f(txn):

            rows = self._get_members_rows_txn(
                txn,
                room_id=room_id,
                membership=Membership.JOIN,
            )

            return [r["user_id"] for r in rows]
        return self.runInteraction("get_users_in_room", f)

    def get_room_members(self, room_id, membership=None):
        """Retrieve the current room member list for a room.

        Args:
            room_id (str): The room to get the list of members.
            membership (synapse.api.constants.Membership): The filter to apply
            to this list, or None to return all members with some state
            associated with this room.
        Returns:
            list of namedtuples representing the members in this room.
        """
        return self.runInteraction(
            "get_room_members",
            self._get_members_events_txn,
            room_id,
            membership=membership,
        ).addCallback(self._get_events)

    def get_invites_for_user(self, user_id):
        """ Get all the invite events for a user
        Args:
            user_id (str): The user ID.
        Returns:
            A deferred list of event objects.
        """

        return self.get_rooms_for_user_where_membership_is(
            user_id, [Membership.INVITE]
        ).addCallback(lambda invites: self._get_events([
            invite.event_id for invite in invites
        ]))

    def get_leave_and_ban_events_for_user(self, user_id):
        """ Get all the leave events for a user
        Args:
            user_id (str): The user ID.
        Returns:
            A deferred list of event objects.
        """
        return self.get_rooms_for_user_where_membership_is(
            user_id, (Membership.LEAVE, Membership.BAN)
        ).addCallback(lambda leaves: self._get_events([
            leave.event_id for leave in leaves
        ]))

    def get_rooms_for_user_where_membership_is(self, user_id, membership_list):
        """ Get all the rooms for this user where the membership for this user
        matches one in the membership list.

        Args:
            user_id (str): The user ID.
            membership_list (list): A list of synapse.api.constants.Membership
            values which the user must be in.
        Returns:
            A list of dictionary objects, with room_id, membership and sender
            defined.
        """
        if not membership_list:
            return defer.succeed(None)

        return self.runInteraction(
            "get_rooms_for_user_where_membership_is",
            self._get_rooms_for_user_where_membership_is_txn,
            user_id, membership_list
        )

    def _get_rooms_for_user_where_membership_is_txn(self, txn, user_id,
                                                    membership_list):
        where_clause = "user_id = ? AND (%s) AND forgotten = 0" % (
            " OR ".join(["membership = ?" for _ in membership_list]),
        )

        args = [user_id]
        args.extend(membership_list)

        sql = (
            "SELECT m.room_id, m.sender, m.membership, m.event_id, e.stream_ordering"
            " FROM current_state_events as c"
            " INNER JOIN room_memberships as m"
            " ON m.event_id = c.event_id"
            " INNER JOIN events as e"
            " ON e.event_id = c.event_id"
            " AND m.room_id = c.room_id"
            " AND m.user_id = c.state_key"
            " WHERE %s"
        ) % (where_clause,)

        txn.execute(sql, args)
        return [
            RoomsForUser(**r) for r in self.cursor_to_dict(txn)
        ]

    @cached(max_entries=5000)
    def get_joined_hosts_for_room(self, room_id):
        return self.runInteraction(
            "get_joined_hosts_for_room",
            self._get_joined_hosts_for_room_txn,
            room_id,
        )

    def _get_joined_hosts_for_room_txn(self, txn, room_id):
        rows = self._get_members_rows_txn(
            txn,
            room_id, membership=Membership.JOIN
        )

        joined_domains = set(
            UserID.from_string(r["user_id"]).domain
            for r in rows
        )

        return joined_domains

    def _get_members_events_txn(self, txn, room_id, membership=None, user_id=None):
        rows = self._get_members_rows_txn(
            txn,
            room_id, membership, user_id,
        )
        return [r["event_id"] for r in rows]

    def _get_members_rows_txn(self, txn, room_id, membership=None, user_id=None):
        where_clause = "c.room_id = ?"
        where_values = [room_id]

        if membership:
            where_clause += " AND m.membership = ?"
            where_values.append(membership)

        if user_id:
            where_clause += " AND m.user_id = ?"
            where_values.append(user_id)

        sql = (
            "SELECT m.* FROM room_memberships as m"
            " INNER JOIN current_state_events as c"
            " ON m.event_id = c.event_id "
            " AND m.room_id = c.room_id "
            " AND m.user_id = c.state_key"
            " WHERE %(where)s"
        ) % {
            "where": where_clause,
        }

        txn.execute(sql, where_values)
        rows = self.cursor_to_dict(txn)

        return rows

    @cached()
    def get_rooms_for_user(self, user_id):
        return self.get_rooms_for_user_where_membership_is(
            user_id, membership_list=[Membership.JOIN],
        )

    @defer.inlineCallbacks
    def user_rooms_intersect(self, user_id_list):
        """ Checks whether all the users whose IDs are given in a list share a
        room.

        This is a "hot path" function that's called a lot, e.g. by presence for
        generating the event stream. As such, it is implemented locally by
        wrapping logic around heavily-cached database queries.
        """
        if len(user_id_list) < 2:
            defer.returnValue(True)

        deferreds = [self.get_rooms_for_user(u) for u in user_id_list]

        results = yield defer.DeferredList(deferreds, consumeErrors=True)

        # A list of sets of strings giving room IDs for each user
        room_id_lists = [set([r.room_id for r in result[1]]) for result in results]

        # There isn't a setintersection(*list_of_sets)
        ret = len(room_id_lists.pop(0).intersection(*room_id_lists)) > 0

        defer.returnValue(ret)

    @defer.inlineCallbacks
    def forget(self, user_id, room_id):
        """Indicate that user_id wishes to discard history for room_id."""
        def f(txn):
            sql = (
                "UPDATE"
                "  room_memberships"
                " SET"
                "  forgotten = 1"
                " WHERE"
                "  user_id = ?"
                " AND"
                "  room_id = ?"
            )
            txn.execute(sql, (user_id, room_id))
        yield self.runInteraction("forget_membership", f)
        self.was_forgotten_at.invalidate_all()
        self.did_forget.invalidate((user_id, room_id))

    @cachedInlineCallbacks(num_args=2)
    def did_forget(self, user_id, room_id):
        """Returns whether user_id has elected to discard history for room_id.

        Returns False if they have since re-joined."""
        def f(txn):
            sql = (
                "SELECT"
                "  COUNT(*)"
                " FROM"
                "  room_memberships"
                " WHERE"
                "  user_id = ?"
                " AND"
                "  room_id = ?"
                " AND"
                "  forgotten = 0"
            )
            txn.execute(sql, (user_id, room_id))
            rows = txn.fetchall()
            return rows[0][0]
        count = yield self.runInteraction("did_forget_membership", f)
        defer.returnValue(count == 0)

    @cachedInlineCallbacks(num_args=3)
    def was_forgotten_at(self, user_id, room_id, event_id):
        """Returns whether user_id has elected to discard history for room_id at event_id.

        event_id must be a membership event."""
        def f(txn):
            sql = (
                "SELECT"
                "  forgotten"
                " FROM"
                "  room_memberships"
                " WHERE"
                "  user_id = ?"
                " AND"
                "  room_id = ?"
                " AND"
                "  event_id = ?"
            )
            txn.execute(sql, (user_id, room_id, event_id))
            rows = txn.fetchall()
            return rows[0][0]
        forgot = yield self.runInteraction("did_forget_membership_at", f)
        defer.returnValue(forgot == 1)