.

bigfile/_file_zodb.pyx

@@ -159,20 +159,10 @@ class ZSync:
         # zconn = DB.open(transaction_manager=tm)
         # tm.commit()   # zconn.at updated          (zconn.afterCompletion -> zconn.newTransaction)
         # tm.commit()   # zconn.at updated again
-        #
-        # TODO test for that.
-        #zconn.onOpenCallback(zsync)
         zconn.onResyncCallback(zsync)
 
-    """
-    # DB.open() pops .zconn from connection pool and "opens" for usage.
-    # -> resync .wconn to new database view of ZODB connection.
-    #
-    def on_connection_open(zsync):
-        print('ZSync.resync %r %r' % (zsync.zconn, zsync.wconn))
-        zsync.wconn.resync(zconn_at(zsync.zconn))
-    """
-
+    # DB resyncs .zconn onto new database view.
+    # -> resync .wconn to updated database view of ZODB connection.
     def on_connection_resync(zsync):
         #print('\nZZZSync.resync %r %r' % (zsync.zconn, zsync.wconn))
         #import traceback; traceback.print_stack()

lib/tests/test_zodb.py

@@ -341,6 +341,10 @@ def test_zodb_onresync():
     assert t.nresync == 2
     transaction.commit()
     assert t.nresync == 3
+    transaction.commit()
+    assert t.nresync == 4
+    transaction.commit()
+    assert t.nresync == 5
 
     conn.close()