synapse-product/synapse/storage/search.py
2015-10-22 16:54:56 +01:00

111 lines
3.5 KiB
Python

# -*- coding: utf-8 -*-
# Copyright 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 _base import SQLBaseStore
from synapse.storage.engines import PostgresEngine, Sqlite3Engine
from collections import namedtuple
"""The result of a search.
Fields:
rank_map (dict): Mapping event_id -> rank
event_map (dict): Mapping event_id -> event
pagination_token (str): Pagination token
"""
SearchResult = namedtuple("SearchResult", ("rank_map", "event_map", "pagination_token"))
class SearchStore(SQLBaseStore):
@defer.inlineCallbacks
def search_msgs(self, room_ids, search_term, keys):
"""Performs a full text search over events with given keys.
Args:
room_ids (list): List of room ids to search in
search_term (str): Search term to search for
keys (list): List of keys to search in, currently supports
"content.body", "content.name", "content.topic"
Returns:
SearchResult
"""
clauses = []
args = []
# Make sure we don't explode because the person is in too many rooms.
# We filter the results below regardless.
if len(room_ids) < 500:
clauses.append(
"room_id IN (%s)" % (",".join(["?"] * len(room_ids)),)
)
args.extend(room_ids)
local_clauses = []
for key in keys:
local_clauses.append("key = ?")
args.append(key)
clauses.append(
"(%s)" % (" OR ".join(local_clauses),)
)
if isinstance(self.database_engine, PostgresEngine):
sql = (
"SELECT ts_rank_cd(vector, query) AS rank, room_id, event_id"
" FROM plainto_tsquery('english', ?) as query, event_search"
" WHERE vector @@ query"
)
elif isinstance(self.database_engine, Sqlite3Engine):
sql = (
"SELECT 0 as rank, room_id, event_id FROM event_search"
" WHERE value MATCH ?"
)
else:
# This should be unreachable.
raise Exception("Unrecognized database engine")
for clause in clauses:
sql += " AND " + clause
# We add an arbitrary limit here to ensure we don't try to pull the
# entire table from the database.
sql += " ORDER BY rank DESC LIMIT 500"
results = yield self._execute(
"search_msgs", self.cursor_to_dict, sql, *([search_term] + args)
)
results = filter(lambda row: row["room_id"] in room_ids, results)
events = yield self._get_events([r["event_id"] for r in results])
event_map = {
ev.event_id: ev
for ev in events
}
defer.returnValue(SearchResult(
{
r["event_id"]: r["rank"]
for r in results
if r["event_id"] in event_map
},
event_map,
None
))