my module need to write data to the client, for some reason i can not get the whole buffer at once. that is i get a trunk buffer to output now, and i must wait the next trunk buffer and output it. so i have to call ngx_output_http_filter from time to time until the whole data is output?? but i found the first time call ngx_output_http_filter is ok, later(after a timer) i call ngx_output_http_filter will result not i want? is what i do right, or i should implement it by other way?