Brian Pane <[EMAIL PROTECTED]> writes:
> Doug MacEachern wrote:
>
> >does this:
> > end = memchr(s, '\0', n);
> > if (end != NULL)
> > n = end - s;
> >
> >is that just to avoid allocating an extra byte if 's' already contains
> >'\0' at the end? seem like it would be better to waste the extra byte
> >than to scan the whole string with memchr() or at least change that to:
> > if (*(s + (n-1)) == '\0') {
> > n--;
> > }
> >
>
> There's no guarantee that strlen(s) is anywhere near n. It's valid
> for a caller to do this, for example:
> apr_pstrndup(p, "foo", 65536);
It looks to me that in practically all calls to apr_pstrndup() in the
httpd+apr+apr-util source tree the caller has told apr_pstrndup() how
many characters are in the string to duplicate, such that there is no
need to look for any '\0'. The callers want to take the first n bytes
of a longer string and put them in their own complete string.
Clearly we could use an API where the caller says "take these n bytes
of chars, and stick those n bytes + a terminating '\0' in a buffer
allocated from this pool, with minimal overhead."
Whether or not we should change the semantics of the existing function
or use a different name is subject to consideration :)
--
Jeff Trawick | [EMAIL PROTECTED] | PGP public key at web site:
http://www.geocities.com/SiliconValley/Park/9289/
Born in Roswell... married an alien...
