X-Git-Url: https://git.openstreetmap.org./nominatim.git/blobdiff_plain/4a2873617dcbaf58ff6135aa7d8dcb115c0cc5ba..3fb739de9275680d4f482d363f22c535442f0017:/nominatim/tools/freeze.py

diff --git a/nominatim/tools/freeze.py b/nominatim/tools/freeze.py
index cc1bf97e..602def55 100644
--- a/nominatim/tools/freeze.py
+++ b/nominatim/tools/freeze.py
@@ -1,8 +1,19 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# This file is part of Nominatim. (https://nominatim.org)
+#
+# Copyright (C) 2022 by the Nominatim developer community.
+# For a full list of authors see the git log.
 """
 Functions for removing unnecessary data from the database.
 """
+from typing import Optional
 from pathlib import Path
 
+from psycopg2 import sql as pysql
+
+from nominatim.db.connection import Connection
+
 UPDATE_TABLES = [
     'address_levels',
     'gb_postcode',
@@ -17,27 +28,31 @@ UPDATE_TABLES = [
     'wikipedia_%'
 ]
 
-def drop_update_tables(conn):
+def drop_update_tables(conn: Connection) -> None:
     """ Drop all tables only necessary for updating the database from
         OSM replication data.
     """
-
-    where = ' or '.join(["(tablename LIKE '{}')".format(t) for t in UPDATE_TABLES])
+    parts = (pysql.SQL("(tablename LIKE {})").format(pysql.Literal(t)) for t in UPDATE_TABLES)
 
     with conn.cursor() as cur:
-        cur.execute("SELECT tablename FROM pg_tables WHERE " + where)
+        cur.execute(pysql.SQL("SELECT tablename FROM pg_tables WHERE ")
+                    + pysql.SQL(' or ').join(parts))
         tables = [r[0] for r in cur]
 
         for table in tables:
-            cur.execute('DROP TABLE IF EXISTS "{}" CASCADE'.format(table))
+            cur.drop_table(table, cascade=True)
 
     conn.commit()
 
 
-def drop_flatnode_file(fname):
+def drop_flatnode_file(fpath: Optional[Path]) -> None:
     """ Remove the flatnode file if it exists.
     """
-    if fname:
-        fpath = Path(fname)
-        if fpath.exists():
-            fpath.unlink()
+    if fpath and fpath.exists():
+        fpath.unlink()
+
+def is_frozen(conn: Connection) -> bool:
+    """ Returns true if database is in a frozen state
+    """
+
+    return conn.table_exists('place') is False