if (!conf->ignore_client) {
        if (!r->gzip_tested) {
            if (ngx_http_gzip_ok(r) == NGX_OK) {
                return ngx_http_next_header_filter(r);
            }
        } else if (r->gzip_ok) {
            return ngx_http_next_header_filter(r);
        }
    }