@chaizhenhua 
re: "maybe, but i dont know how to use it."

I think you could do something something like
```
  ps_main_conf_t* cfg_m = static_cast<ps_main_conf_t*>(
      ngx_http_cycle_get_module_main_conf(cycle, ngx_pagespeed));
 cfg_m->handler->Message(net_instaweb::kError, "your message here");
```