'Store the current checkpoint in the oplog progress dictionary.'

def update_checkpoint(self, checkpoint):

    if ((checkpoint is not None) and (checkpoint != self.checkpoint)):
        self.checkpoint = checkpoint
        with self.oplog_progress as oplog_prog:
            oplog_dict = oplog_prog.get_dict()
            oplog_dict.pop(str(self.oplog), None)
            oplog_dict[self.replset_name] = checkpoint
            LOG.debug('OplogThread:    oplog    checkpoint    updated    to    %s', checkpoint)
    else:
        LOG.debug('OplogThread:    no    checkpoint    to    update.')
