Here’s my slides from Railsconf. More thoughts to come once I recover a bit more - it was pretty intense for my partners and I this year, what with doing three talks and manning a booth.
Someone in the session asked to see get_logged_in_user() (called from the code shown in slide 36). Here it is, in all its C string-manipulation glory:
void get_logged_in_user(ngx_http_request_t *r, u_char *user, int user_size)
{
ngx_table_elt_t **cookies;
ngx_table_elt_t *elt;
char cookie[256] = "";
int i;
cookies = r->headers_in.cookies.elts;
for (i = 0; i < (int)r->headers_in.cookies.nelts; i++)
{
elt = cookies[i];
if (extract_and_overwrite_cookie((char *)elt->value.data, "heroku_session=", cookie, sizeof(cookie)))
break;
}
if (cookie[0] != 0)
find_user_by_cookie(cookie, (char *)user, user_size);
}
void find_user_by_cookie(const char *cookie, char *email, int size)
{
char sql[256], scratch[128];
snprintf(sql, sizeof(sql)-1,
"SELECT username FROM sessions WHERE cookie='%s'",
pg_escape(cookie, scratch, sizeof(scratch)));
pg_select_one_string(sql, email, size);
}
Also, one correction: I incorrectly stated that redirect() was an Nginx function. It’s actually a helper function I created; here’s the code.
void redirect(ngx_http_request_t *r, char *url)
{
location = ngx_palloc(r->pool, strlen(url));
r->headers_out.location = ngx_palloc(r->pool, sizeof(ngx_table_elt_t));
ngx_copy(location, url, strlen(url));
r->headers_out.location->value.data = location;
r->headers_out.location->value.len = strlen(url);
r->headers_out.content_length_n = 0;
r->header_only = 1;
r->keepalive = 0;
}
If you use this, make sure to return NGX_HTTP_MOVED_TEMPORARILY immediately after calling it, as shown in the slides.