/*-
 * Copyright (c) 1990, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Chris Torek.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * @(#)fread.c  8.2 (Berkeley) 12/11/93
 * $FreeBSD: src/lib/libc/stdio/fread.c,v 1.15 2008/12/01 14:33:34 ru Exp $
 */

#include "namespace.h"
#include <stdio.h>
#include <string.h>
#include "un-namespace.h"
#include "local.h"
#include "libc_private.h"

/*
 * MT-safe version
 */

size_t
fread(void * __restrict buf, size_t size, size_t count, FILE * __restrict fp)
{
        size_t ret;

        FLOCKFILE(fp);
        ret = __fread(buf, size, count, fp);
        FUNLOCKFILE(fp);
        return (ret);
}

size_t
__fread(void * __restrict buf, size_t size, size_t count, FILE * __restrict fp)
{
        size_t resid;
        char *p;
        int r;
        size_t total;

        /*
         * The ANSI standard requires a return value of 0 for a count
         * or a size of 0.  Peculiarily, it imposes no such requirements
         * on fwrite; it only requires fread to be broken.
         */
        if ((resid = count * size) == 0)
                return (0);
        ORIENT(fp, -1);
        if (fp->pub._r < 0)
                fp->pub._r = 0;
        total = resid;
        p = buf;
        while (resid > (r = fp->pub._r)) {
                memcpy((void *)p, (void *)fp->pub._p, (size_t)r);
                fp->pub._p += r;
                /* fp->pub._r = 0 ... done in __srefill */
                p += r;
                resid -= r;
                if (__srefill(fp)) {
                        /* no more input: return partial result */
                        return ((total - resid) / size);
                }
        }
        memcpy((void *)p, (void *)fp->pub._p, resid);
        fp->pub._r -= resid;
        fp->pub._p += resid;
        return (count);
}

__weak_reference(__fread, fread_unlocked);