A small performance patch for consideration:
Currently, mod_mime scans through the extensions in the
requested filename using ap_getword, which does a strdup
of each extension.
This patch replaces the ap_getword loop with an inline scan
that doesn't do apr_pstrdup. Based on past function call profiles
that I've done, this change should eliminate 15-20% of the
ap_pstrdup calls in the httpd. (I'll try to address the other
80-85% with some future patches; apr_pstrdup currently is one
of the top 10 consumers of usr-mode CPU time in the httpd,
so it's worthwhile to optimize it away where possible.)
Important note: on platforms with case-insensitive filenames,
the elimination of the strdup means that this patch will result
in the extensions in request_rec->filename being converted
to lowercase. I assume that's not a problem, but if it is I
can add some code to do a strdup on (only) the affected platforms.
--Brian
Index: mod_mime.c
===================================================================
RCS file: /home/cvspublic/httpd-2.0/modules/http/mod_mime.c,v
retrieving revision 1.43
diff -r1.43 mod_mime.c
778c778,779
< while ((ext = ap_getword(r->pool, &fn, '.')) && *ext) {
---
> ext = ap_strchr(fn, '.');
> while (ext) {
780a782,789
> char *nextdot;
>
> ext++; /* skip the '.' */
> if (!*ext)
> break;
> nextdot = ap_strchr(ext, '.');
> if (nextdot)
> *nextdot = 0;
846a856,863
>
> /* Restore the '.' that starts the next extension, if applicable */
> if (nextdot) {
> *nextdot = '.';
> ext = nextdot;
> }
> else
> break;
Index: mod_mime.c
===================================================================
RCS file: /home/cvspublic/httpd-2.0/modules/http/mod_mime.c,v
retrieving revision 1.43
diff -r1.43 mod_mime.c
778c778,779
< while ((ext = ap_getword(r->pool, &fn, '.')) && *ext) {
---
> ext = ap_strchr_c(fn, '.');
> while (ext) {
780a782,789
> char *nextdot;
>
> ext++; /* skip the '.' */
> if (!*ext)
> break;
> nextdot = ap_strchr_c(ext, '.');
> if (nextdot)
> *nextdot = 0;
846a856,863
>
> /* Restore the '.' that starts the next extension, if applicable */
> if (nextdot) {
> *nextdot = '.';
> ext = nextdot;
> }
> else
> break;
