Manlio Perillo wrote:
Hi again.
I have decided to write mod_wsgi by myself, and I have fuond the Evan
Miller's guide very helful.
Glad it was useful. I'll try to keep updating it with more info, but in
the meantime I thought I'd try to answer your specific questions (below).
However I think that some important documentation is missing:
1) The overall architecture of nginx
2) nginx memory handling
Nginx has a pool of memory associated with each request (r->pool), which
is reclaimed at the end of the request. You can malloc memory with
ngx_palloc(r->pool, BYTES). I'm not sure whether you can free memory
allocated in this way manually.
3) how to read data from the request payload
I'm not sure, actually; but check out
http://www.riceonfire.org/lxr/http/source/http/ngx_http_request_body.c
4) how to read and generate arbitrary headers
There is an headers attribute in the request struct, what is its
content?
I read headers by looking for the variable names that are set (e.g.
"upstream_http_x_my_header"). The ngx_http_variable_unknown_header()
function comes in handy.
To set a header, I think you'd use functions in the Headers module,
something like (making it up here):
ngx_http_headers_conf_t *hcf = ngx_http_get_module_loc_conf(r,
ngx_http_headers_module);
ngx_http_header_val_t *h = ngx_array_push(hcf->headers);
if (h == NULL) { return NGX_ERROR; }
h->value.hash = 1;
h->value.key = ngx_string("X-My-Header");
h->value.value = ngx_string("Some value");
...
5) More about chain links.
When sending the response body, we have two choices
(but I'm not sure):
- write the entire chain links and then pass it to the output filter
(so we buffer the entire response)
- create a partial response, create a buffer and call the output
filter, then create a new partial response, create a new buffer and
call the outputfilter, and so on.
I believe that's correct.
When I research these issues more I'll add them to the guide.
Good luck with mod_wsgi! I know it's a module a lot of people would find
useful.
Evan
4 messages in ru.sysoev.nginxRe: about the Guide to Nginx Module D...
