Re: apr_strcat optimization(s)

[dean gaudet <de...@arctic.org>]

you might as well memcpy() if you're going to strlen() first.  it's less
complex inline code.

-dean

On Tue, 19 Jun 2001, Doug MacEachern wrote:

> the current apr_strcat does strlen() twice for each argument, this patch
> makes it happen just once.  it would also be handy to have an apr_pstrcatn
> (name debatable) that returns the calculated length so the caller can
> avoid another strlen(), something like:
>
> apr_size_t total_len;
> apr_status_t status = apr_pstrcatn(pool, &total_len, ..., NULL);
>
> then apr_pstrcat() would just be a wrapper around apr_pstrcatn().
> i'll get a patch together if the name/prototype is agreed on.
>
> --- srclib/apr/strings/apr_strings.c    2001/05/10 18:05:18     1.13
> +++ srclib/apr/strings/apr_strings.c    2001/06/19 17:12:01
> @@ -137,8 +137,9 @@
>      va_start(adummy, a);
>
>      while ((argp = va_arg(adummy, char *)) != NULL) {
> -        strcpy(cp, argp);
> -        cp += strlen(argp);
> +        len = strlen(argp);
> +        strncpy(cp, argp, len);
> +        cp += len;
>      }
>
>      va_end(adummy);
>
>
>

Re: apr_strcat optimization(s)

[dean gaudet <de...@arctic.org>]

btw, if you study the assembly for any inline strcpy() implementation
you'll find it has a pointer to the end (NUL) of the result anyhow.  in
some ancient msdos/windows/os2/etc. c libraries there is a function
stpcpy()  which returns the pointer to the end of the result, which is
probably a million times more useful than returning the result again.

(you can see i stuck my_stpcpy() into mod_test_util_uri.c ... of course
it's not a nicely optimised inline version :)

-dean

On Tue, 17 Jul 2001, dean gaudet wrote:

> you might as well memcpy() if you're going to strlen() first.  it's less
> complex inline code.
>
> -dean
>
> On Tue, 19 Jun 2001, Doug MacEachern wrote:
>
> > the current apr_strcat does strlen() twice for each argument, this patch
> > makes it happen just once.  it would also be handy to have an apr_pstrcatn
> > (name debatable) that returns the calculated length so the caller can
> > avoid another strlen(), something like:
> >
> > apr_size_t total_len;
> > apr_status_t status = apr_pstrcatn(pool, &total_len, ..., NULL);
> >
> > then apr_pstrcat() would just be a wrapper around apr_pstrcatn().
> > i'll get a patch together if the name/prototype is agreed on.
> >
> > --- srclib/apr/strings/apr_strings.c    2001/05/10 18:05:18     1.13
> > +++ srclib/apr/strings/apr_strings.c    2001/06/19 17:12:01
> > @@ -137,8 +137,9 @@
> >      va_start(adummy, a);
> >
> >      while ((argp = va_arg(adummy, char *)) != NULL) {
> > -        strcpy(cp, argp);
> > -        cp += strlen(argp);
> > +        len = strlen(argp);
> > +        strncpy(cp, argp, len);
> > +        cp += len;
> >      }
> >
> >      va_end(adummy);
> >
> >
> >
>
>