support new ReplicationServer as contextmanager

nominatim/tools/replication.py

@@ -7,6 +7,7 @@
 """
 Functions for updating a database from a replication source.
 """
+from contextlib import contextmanager
 import datetime as dt
 from enum import Enum
 import logging
@@ -109,8 +110,7 @@ def update(conn, options):
         options['import_file'].unlink()
 
     # Read updates into file.
-    repl = ReplicationServer(options['base_url'])
+    with _make_replication_server(options['base_url']) as repl:
-
         outhandler = WriteHandler(str(options['import_file']))
         endseq = repl.apply_diffs(outhandler, startseq + 1,
                                   max_size=options['max_diff_size'] * 1024)
@@ -130,3 +130,19 @@ def update(conn, options):
                           seq=endseq, indexed=False)
 
     return UpdateState.UP_TO_DATE
+
+
+def _make_replication_server(url):
+    """ Returns a ReplicationServer in form of a context manager.
+
+        Creates a light wrapper around older versions of pyosmium that did
+        not support the context manager interface.
+    """
+    if hasattr(ReplicationServer, '__enter__'):
+        return ReplicationServer(url)
+
+    @contextmanager
+    def get_cm():
+        yield ReplicationServer(url)
+
+    return get_cm()