watcha-synapse/synapse/storage/stream.py

# -*- coding: utf-8 -*-
# Copyright 2014 matrix.org
#
# 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 SQLBaseStore
from .message import MessagesTable
from .feedback import FeedbackTable
from .roomdata import RoomDataTable
from .roommember import RoomMemberTable

import json
import logging

logger = logging.getLogger(__name__)


class StreamStore(SQLBaseStore):

    def get_message_stream(self, user_id, from_key, to_key, room_id, limit=0,
                           with_feedback=False):
        """Get all messages for this user between the given keys.

        Args:
            user_id (str): The user who is requesting messages.
            from_key (int): The ID to start returning results from (exclusive).
            to_key (int): The ID to stop returning results (exclusive).
            room_id (str): Gets messages only for this room. Can be None, in
            which case all room messages will be returned.
        Returns:
            A tuple of rows (list of namedtuples), new_id(int)
        """
        if with_feedback and room_id:  # with fb MUST specify a room ID
            return self._db_pool.runInteraction(
                self._get_message_rows_with_feedback,
                user_id, from_key, to_key, room_id, limit
            )
        else:
            return self._db_pool.runInteraction(
                self._get_message_rows,
                user_id, from_key, to_key, room_id, limit
            )

    def _get_message_rows(self, txn, user_id, from_pkey, to_pkey, room_id,
                          limit):
        # work out which rooms this user is joined in on and join them with
        # the room id on the messages table, bounded by the specified pkeys

        # get all messages where the *current* membership state is 'join' for
        # this user in that room.
        query = ("SELECT messages.* FROM messages WHERE ? IN"
                 + " (SELECT membership from room_memberships WHERE user_id=?"
                 + " AND room_id = messages.room_id ORDER BY id DESC LIMIT 1)")
        query_args = ["join", user_id]

        if room_id:
            query += " AND messages.room_id=?"
            query_args.append(room_id)

        (query, query_args) = self._append_stream_operations(
            "messages", query, query_args, from_pkey, to_pkey, limit=limit
        )

        logger.debug("[SQL] %s : %s", query, query_args)
        cursor = txn.execute(query, query_args)
        return self._as_events(cursor, MessagesTable, from_pkey)

    def _get_message_rows_with_feedback(self, txn, user_id, from_pkey, to_pkey,
                                        room_id, limit):
        # this col represents the compressed feedback JSON as per spec
        compressed_feedback_col = (
            "'[' || group_concat('{\"sender_id\":\"' || f.fb_sender_id"
            + " || '\",\"feedback_type\":\"' || f.feedback_type"
            + " || '\",\"content\":' || f.content || '}') || ']'"
        )

        global_msg_id_join = ("f.room_id = messages.room_id"
                              + " and f.msg_id = messages.msg_id"
                              + " and messages.user_id = f.msg_sender_id")

        select_query = (
            "SELECT messages.*, f.content AS fb_content, f.fb_sender_id"
            + ", " + compressed_feedback_col + " AS compressed_fb"
            + " FROM messages LEFT JOIN feedback f ON " + global_msg_id_join)

        current_membership_sub_query = (
            "(SELECT membership from room_memberships rm"
            + " WHERE user_id=? AND room_id = rm.room_id"
            + " ORDER BY id DESC LIMIT 1)")

        where = (" WHERE ? IN " + current_membership_sub_query
                 + " AND messages.room_id=?")

        query = select_query + where
        query_args = ["join", user_id, room_id]

        (query, query_args) = self._append_stream_operations(
            "messages", query, query_args, from_pkey, to_pkey,
            limit=limit, group_by=" GROUP BY messages.id "
        )

        logger.debug("[SQL] %s : %s", query, query_args)
        cursor = txn.execute(query, query_args)

        # convert the result set into events
        entries = self.cursor_to_dict(cursor)
        events = []
        for entry in entries:
            # TODO we should spec the cursor > event mapping somewhere else.
            event = {}
            straight_mappings = ["msg_id", "user_id", "room_id"]
            for key in straight_mappings:
                event[key] = entry[key]
            event["content"] = json.loads(entry["content"])
            if entry["compressed_fb"]:
                event["feedback"] = json.loads(entry["compressed_fb"])
            events.append(event)

        latest_pkey = from_pkey if len(entries) == 0 else entries[-1]["id"]

        return (events, latest_pkey)

    def get_room_member_stream(self, user_id, from_key, to_key):
        """Get all room membership events for this user between the given keys.

        Args:
            user_id (str): The user who is requesting membership events.
            from_key (int): The ID to start returning results from (exclusive).
            to_key (int): The ID to stop returning results (exclusive).
        Returns:
            A tuple of rows (list of namedtuples), new_id(int)
        """
        return self._db_pool.runInteraction(
            self._get_room_member_rows, user_id, from_key, to_key
        )

    def _get_room_member_rows(self, txn, user_id, from_pkey, to_pkey):
        # get all room membership events for rooms which the user is
        # *currently* joined in on, or all invite events for this user.
        current_membership_sub_query = (
            "(SELECT membership FROM room_memberships"
            + " WHERE user_id=? AND room_id = rm.room_id"
            + " ORDER BY id DESC LIMIT 1)")

        query = ("SELECT rm.* FROM room_memberships rm "
                 # all membership events for rooms you've currently joined.
                 + " WHERE (? IN " + current_membership_sub_query
                 # all invite membership events for this user
                 + " OR rm.membership=? AND user_id=?)"
                 + " AND rm.id > ?")
        query_args = ["join", user_id, "invite", user_id, from_pkey]

        if to_pkey != -1:
            query += " AND rm.id < ?"
            query_args.append(to_pkey)

        cursor = txn.execute(query, query_args)
        return self._as_events(cursor, RoomMemberTable, from_pkey)

    def get_feedback_stream(self, user_id, from_key, to_key, room_id, limit=0):
        return self._db_pool.runInteraction(
            self._get_feedback_rows,
            user_id, from_key, to_key, room_id, limit
        )

    def _get_feedback_rows(self, txn, user_id, from_pkey, to_pkey, room_id,
                           limit):
        # work out which rooms this user is joined in on and join them with
        # the room id on the feedback table, bounded by the specified pkeys

        # get all messages where the *current* membership state is 'join' for
        # this user in that room.
        query = (
            "SELECT feedback.* FROM feedback WHERE ? IN "
            + "(SELECT membership from room_memberships WHERE user_id=?"
            + " AND room_id = feedback.room_id ORDER BY id DESC LIMIT 1)")
        query_args = ["join", user_id]

        if room_id:
            query += " AND feedback.room_id=?"
            query_args.append(room_id)

        (query, query_args) = self._append_stream_operations(
            "feedback", query, query_args, from_pkey, to_pkey, limit=limit
        )

        logger.debug("[SQL] %s : %s", query, query_args)
        cursor = txn.execute(query, query_args)
        return self._as_events(cursor, FeedbackTable, from_pkey)

    def get_room_data_stream(self, user_id, from_key, to_key, room_id,
                             limit=0):
        return self._db_pool.runInteraction(
            self._get_room_data_rows,
            user_id, from_key, to_key, room_id, limit
        )

    def _get_room_data_rows(self, txn, user_id, from_pkey, to_pkey, room_id,
                            limit):
        # work out which rooms this user is joined in on and join them with
        # the room id on the feedback table, bounded by the specified pkeys

        # get all messages where the *current* membership state is 'join' for
        # this user in that room.
        query = (
            "SELECT room_data.* FROM room_data WHERE ? IN "
            + "(SELECT membership from room_memberships WHERE user_id=?"
            + " AND room_id = room_data.room_id ORDER BY id DESC LIMIT 1)")
        query_args = ["join", user_id]

        if room_id:
            query += " AND room_data.room_id=?"
            query_args.append(room_id)

        (query, query_args) = self._append_stream_operations(
            "room_data", query, query_args, from_pkey, to_pkey, limit=limit
        )

        logger.debug("[SQL] %s : %s", query, query_args)
        cursor = txn.execute(query, query_args)
        return self._as_events(cursor, RoomDataTable, from_pkey)

    def _append_stream_operations(self, table_name, query, query_args,
                                  from_pkey, to_pkey, limit=None,
                                  group_by=""):
        LATEST_ROW = -1
        order_by = ""
        if to_pkey > from_pkey:
            if from_pkey != LATEST_ROW:
                # e.g. from=5 to=9 >> from 5 to 9 >> id>5 AND id<9
                query += (" AND %s.id > ? AND %s.id < ?" %
                         (table_name, table_name))
                query_args.append(from_pkey)
                query_args.append(to_pkey)
            else:
                # e.g. from=-1 to=5 >> from now to 5 >> id>5 ORDER BY id DESC
                query += " AND %s.id > ? " % table_name
                order_by = "ORDER BY id DESC"
                query_args.append(to_pkey)
        elif from_pkey > to_pkey:
            if to_pkey != LATEST_ROW:
                # from=9 to=5 >> from 9 to 5 >> id>5 AND id<9 ORDER BY id DESC
                query += (" AND %s.id > ? AND %s.id < ? " %
                          (table_name, table_name))
                order_by = "ORDER BY id DESC"
                query_args.append(to_pkey)
                query_args.append(from_pkey)
            else:
                # from=5 to=-1 >> from 5 to now >> id>5
                query += " AND %s.id > ?" % table_name
                query_args.append(from_pkey)

        query += group_by + order_by

        if limit and limit > 0:
            query += " LIMIT ?"
            query_args.append(str(limit))

        return (query, query_args)

    def _as_events(self, cursor, table, from_pkey):
        data_entries = table.decode_results(cursor)
        last_pkey = from_pkey
        if data_entries:
            last_pkey = data_entries[-1].id

        events = [
            entry.as_event(self.event_factory).get_dict()
            for entry in data_entries
        ]

        return (events, last_pkey)