diff options
Diffstat (limited to 'synapse/storage/engines/sqlite3.py')
| -rw-r--r-- | synapse/storage/engines/sqlite3.py | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/synapse/storage/engines/sqlite3.py b/synapse/storage/engines/sqlite3.py index bad3b5c5ac..a5a54ec011 100644 --- a/synapse/storage/engines/sqlite3.py +++ b/synapse/storage/engines/sqlite3.py @@ -17,6 +17,8 @@ from synapse.storage.prepare_database import ( prepare_database, prepare_sqlite3_database ) +import struct + class Sqlite3Engine(object): single_threaded = True @@ -32,6 +34,7 @@ class Sqlite3Engine(object): def on_new_connection(self, db_conn): self.prepare_database(db_conn) + db_conn.create_function("rank", 1, _rank) def prepare_database(self, db_conn): prepare_sqlite3_database(db_conn) @@ -45,3 +48,27 @@ class Sqlite3Engine(object): def lock_table(self, txn, table): return + + +# Following functions taken from: https://github.com/coleifer/peewee + +def _parse_match_info(buf): + bufsize = len(buf) + return [struct.unpack('@I', buf[i:i+4])[0] for i in range(0, bufsize, 4)] + + +def _rank(raw_match_info): + """Handle match_info called w/default args 'pcx' - based on the example rank + function http://sqlite.org/fts3.html#appendix_a + """ + match_info = _parse_match_info(raw_match_info) + score = 0.0 + p, c = match_info[:2] + for phrase_num in range(p): + phrase_info_idx = 2 + (phrase_num * c * 3) + for col_num in range(c): + col_idx = phrase_info_idx + (col_num * 3) + x1, x2 = match_info[col_idx:col_idx + 2] + if x1 > 0: + score += float(x1) / x2 + return score |