# in file -> /usr/lib/rhythmbox/plugins/rb/Loader.py
def get_url_chunks (self, uri, chunksize, want_size, callback, *args):
                # this can't possibly work yet, we need to get annotations and
                # other stuff for g_input_stream_read_async right first.
                raise Exception("rb.ChunkLoader not implemented yet")

                try:
                        self.uri = uri
                        self.chunksize = chunksize
                        self.total = 0
                        self.callback = callback
                        self.args = args

                        file = Gio.File(uri)
                        if want_size:
                                file.query_info_async(Gio.FILE_ATTRIBUTE_STANDARD_SIZE, Gio.FileQueryInfoFlags.NONE, GLib.PRIORITY_DEFAULT, self._cancel, self._info_cb, None)
                        else:
                                file.read_async(GLib.PRIORITY_DEFAULT, self._cancel, self._open_cb, None)
                except Exception, e:
                        print "error reading file %s: %s" % (uri, e.message)
                        self._callback(e)