On Fri, Dec 14, 2018 at 10:49:23AM -0700, Todd C. Miller wrote:
> On Fri, 14 Dec 2018 08:45:31 +0100, Sebastien Marie wrote:
>
> After thinking about this a bit more I believe it best to just use
> the existing FILE * and swap in the buffer temporarily. There's
> no need to store the value of the old buffer; since we are unbuffered
> it can only point to _nbuf.
>
> This is simpler and should address all of your concerns.
>
yes, I am fine with it. thanks.
ok semarie@
> Index: lib/libc/stdio/fread.c
> ===================================================================
> RCS file: /cvs/src/lib/libc/stdio/fread.c,v
> retrieving revision 1.15
> diff -u -p -u -r1.15 fread.c
> --- lib/libc/stdio/fread.c 21 Sep 2016 04:38:56 -0000 1.15
> +++ lib/libc/stdio/fread.c 14 Dec 2018 17:48:46 -0000
> @@ -69,18 +69,33 @@ fread(void *buf, size_t size, size_t cou
> total = resid;
> p = buf;
>
> - if ((fp->_flags & __SNBF) != 0) {
> - /*
> - * We know if we're unbuffered that our buffer is empty, so
> - * we can just read directly. This is much faster than the
> - * loop below which will perform a series of one byte reads.
> - */
> - while (resid > 0 && (r = (*fp->_read)(fp->_cookie, p, resid)) >
> 0) {
> - p += r;
> - resid -= r;
> + /*
> + * If we're unbuffered we know that the buffer in fp is empty so
> + * we can read directly into buf. This is much faster than a
> + * series of one byte reads into fp->_nbuf.
> + */
> + if ((fp->_flags & __SNBF) != 0 && buf != NULL) {
> + /* set up the buffer */
> + fp->_bf._base = fp->_p = buf;
> + fp->_bf._size = total;
> +
> + while (resid > 0) {
> + if (__srefill(fp)) {
> + /* no more input: return partial result */
> + count = (total - resid) / size;
> + break;
> + }
> + fp->_p += fp->_r;
> + resid -= fp->_r;
> }
> +
> + /* restore the old buffer (see __smakebuf) */
> + fp->_bf._base = fp->_p = fp->_nbuf;
> + fp->_bf._size = 1;
> + fp->_r = 0;
> +
> FUNLOCKFILE(fp);
> - return ((total - resid) / size);
> + return (count);
> }
>
> while (resid > (r = fp->_r)) {
--
Sebastien Marie
