nginx-lua and nginx upload module

[Valery Kholodkov]

----- agentzh <agentzh at gmail.com> wrote:
> On Mon, Nov 28, 2011 at 6:22 PM, Valery Kholodkov
> <valery+nginxen at grid.net.ru> wrote:
> >
> > I think we've been able to do that even before.
> 
> Sadly for nginx 0.8.41 ~ 0.8.53, "IO interruptions" are explicitly
> prohibited in rewrite phase handlers and for exactly the same reason
> your ngx_eval module does not work at all for these versions of Nginx
> :)
> 
> > But that's not point. The problem is not in what particular phase upload module will run, but that it must run whenever some module tries to read the request body. This kind of customisation is not supported by nginx yet.
> >
> 
> True. We definitely need an input filter mechanism for Nginx. I've
> cc'd Andrew Alexeev. Maybe he can help make this happen in the Nginx
> core ;)
> 
> >
> > Again, the point is not in what particular phase it will run... And by the way, the costs of internal redirects are negligible.
> >
> 
> Not really if the user has a lot of regex style locations defined in
> his nginx.conf. For now, the nginx core does not (yet) utilize the
> PCRE JIT feature for its pattern matching, so it does consume quite a
> few CPU cycles for complicated location patterns ;) And...if we *can*
> eliminate the cost of internal redirects altogether, why shouldn't we
> make that happen? ;)

Did you mean "quite a lot"?

> 
> Also, I believe it can simplify the user config file greatly and does
> not cause variable scope problems (like $uri and $args' scope). I know
> there is a upload_pass_args directive to forward the original URI
> query args, but if the $args scope issue does not exist in the first
> place, we do not need this config directive at all.
> 
> BTW, I notice that if ngx_upload's special variables like
> $upload_file_md5 are used in a wrong context, it will simply crash the
> nginx worker (segmentation faults) due to null module context pointer
> access (at least for the latest 2.2.0 release).

I'll add a check for that.

> Maybe it's more
> reasonable to check the ctx pointer and print out a helpful error
> message in functions like ngx_http_upload_md5_variable?

-- 
Regards,
Valery Kholodkov