Flush handling WIP.

Signed-off-by: Daira Hopwood <daira@jacaranda.org>

src/allmydata/test/test_magic_folder.py

@@ -621,10 +621,9 @@ def _check_file(self, name_u, data, temporary=False, directory=False):
                 f.close()
             if temporary and sys.platform == "win32":
                 os.unlink(path_u)
-                self.notify(path, self.inotify.IN_DELETE)
+                self.notify(path, self.inotify.IN_DELETE, flush=False)
             event_mask = self.inotify.IN_CLOSE_WRITE
 
-        fileutil.flush_volume(path_u)
         self.notify(path, event_mask)
         encoded_name_u = magicpath.path2magic(name_u)
 
@@ -733,7 +732,7 @@ def Alice_to_delete_file():
         def notify_bob_moved(ign):
             d0 = self.bob_magicfolder.uploader.set_hook('processed')
             p = abspath_expanduser_unicode(u"file1", base=self.bob_magicfolder.uploader._local_path_u)
-            self.notify(to_filepath(p), self.inotify.IN_MOVED_FROM, magic=self.bob_magicfolder)
+            self.notify(to_filepath(p), self.inotify.IN_MOVED_FROM, magic=self.bob_magicfolder, flush=False)
             self.notify(to_filepath(p + u'.backup'), self.inotify.IN_MOVED_TO, magic=self.bob_magicfolder)
             bob_clock.advance(0)
             return d0
@@ -869,10 +868,11 @@ def setUp(self):
         self.inotify = fake_inotify
         self.patch(magic_folder, 'get_inotify_module', lambda: self.inotify)
 
-    def notify(self, path, mask, magic=None):
+    def notify(self, path, mask, magic=None, flush=True):
         if magic is None:
             magic = self.magicfolder
         magic.uploader._notifier.event(path, mask)
+        # no flush for the mock test.
 
     def test_errors(self):
         self.set_up_grid()
@@ -959,9 +959,11 @@ def setUp(self):
         MagicFolderTestMixin.setUp(self)
         self.inotify = magic_folder.get_inotify_module()
 
-    def notify(self, path, mask, **kw):
+    def notify(self, path, mask, magic=None, flush=True):
         # Writing to the filesystem causes the notification.
-        pass
+        # However, flushing filesystem buffers may be necessary on Windows.
+        if flush:
+            fileutil.flush_volume(path)
 
 try:
     magic_folder.get_inotify_module()