[apple/libc.git] / stdio / fread-fbsd.c

/*-
 * 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.
 * 4. 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.
 */

#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)fread.c	8.2 (Berkeley) 12/11/93";
#endif /* LIBC_SCCS and not lint */
#include <sys/cdefs.h>
__FBSDID("$FreeBSD: src/lib/libc/stdio/fread.c,v 1.16 2009/07/12 13:09:43 ed 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, ret;
	size_t total;

	/*
	 * ANSI and SUSv2 require a return value of 0 if size or count are 0.
	 */
	if ((resid = count * size) == 0)
		return (0);
	ORIENT(fp, -1);
	if (fp->_r < 0)
		fp->_r = 0;
	total = resid;
	p = buf;
	/* first deal with anything left in buffer, plus any ungetc buffers */
	while (resid > (r = fp->_r)) {
		(void)memcpy((void *)p, (void *)fp->_p, (size_t)r);
		fp->_p += r;
		/* fp->_r = 0 ... done in __srefill */
		p += r;
		resid -= r;
		if ((ret = __srefill0(fp)) > 0)
			break;
		else if (ret) {
			/* no more input: return partial result */
			return ((total - resid) / size);
		}
	}
	/*
	 * 5980080: don't use optimization if __SMBF not set (meaning setvbuf
	 * was called, and the buffer belongs to the user).
	 * 6180417: but for unbuffered (__SMBF is not set), so specifically
	 * test for it.
	 */
	if ((fp->_flags & (__SMBF | __SNBF)) && resid > fp->_bf._size) {
		struct __sbuf save;
		size_t n;

		save = fp->_bf;
		fp->_bf._base = p;
		fp->_bf._size = resid;
		while (fp->_bf._size > 0) {
			if ((ret = __srefill1(fp)) != 0) {
				/* no more input: return partial result */
				resid = fp->_bf._size;
				fp->_bf = save;
				fp->_p = fp->_bf._base;
				/* fp->_r = 0;  already set in __srefill1 */
				return ((total - resid) / size);
			}
			fp->_bf._base += fp->_r;
			fp->_bf._size -= fp->_r;
		}
		fp->_bf = save;
		n = fp->_bf._size * ((resid - 1) / fp->_bf._size);
		r = resid - n;
		(void)memcpy((void *)fp->_bf._base, (void *)(p + n), (size_t)r);
		fp->_p = fp->_bf._base + r;
		fp->_r = 0;
	} else {
		while (resid > (r = fp->_r)) {
			(void)memcpy((void *)p, (void *)fp->_p, (size_t)r);
			fp->_p += r;
			/* fp->_r = 0 ... done in __srefill */
			p += r;
			resid -= r;
			if (__srefill1(fp)) {
				/* no more input: return partial result */
				return ((total - resid) / size);
			}
		}
		(void)memcpy((void *)p, (void *)fp->_p, resid);
		fp->_r -= resid;
		fp->_p += resid;
	}
	return (count);
}
Commit	Line	Data
34e8f829 A	1	/*-
	2	* Copyright (c) 1990, 1993
	3	* The Regents of the University of California. All rights reserved.
	4	*
	5	* This code is derived from software contributed to Berkeley by
	6	* Chris Torek.
	7	*
	8	* Redistribution and use in source and binary forms, with or without
	9	* modification, are permitted provided that the following conditions
	10	* are met:
	11	* 1. Redistributions of source code must retain the above copyright
	12	* notice, this list of conditions and the following disclaimer.
	13	* 2. Redistributions in binary form must reproduce the above copyright
	14	* notice, this list of conditions and the following disclaimer in the
	15	* documentation and/or other materials provided with the distribution.
34e8f829 A	16	* 4. Neither the name of the University nor the names of its contributors
	17	* may be used to endorse or promote products derived from this software
	18	* without specific prior written permission.
	19	*
	20	* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	21	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	22	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	23	* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	24	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	25	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	26	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	27	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	28	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	29	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	30	* SUCH DAMAGE.
	31	*/
	32
	33	#if defined(LIBC_SCCS) && !defined(lint)
	34	static char sccsid[] = "@(#)fread.c 8.2 (Berkeley) 12/11/93";
	35	#endif /* LIBC_SCCS and not lint */
	36	#include <sys/cdefs.h>
1f2f436a	37	__FBSDID("$FreeBSD: src/lib/libc/stdio/fread.c,v 1.16 2009/07/12 13:09:43 ed Exp $");
34e8f829 A	38
	39	#include "namespace.h"
	40	#include <stdio.h>
	41	#include <string.h>
	42	#include "un-namespace.h"
	43	#include "local.h"
	44	#include "libc_private.h"
	45
1f2f436a A	46	/*
	47	* MT-safe version
	48	*/
	49
34e8f829	50	size_t
1f2f436a A	51	fread(void * __restrict buf, size_t size, size_t count, FILE * __restrict fp)
	52	{
	53	size_t ret;
	54
	55	FLOCKFILE(fp);
	56	ret = __fread(buf, size, count, fp);
	57	FUNLOCKFILE(fp);
	58	return (ret);
	59	}
	60
	61	size_t
	62	__fread(void * __restrict buf, size_t size, size_t count, FILE * __restrict fp)
34e8f829 A	63	{
	64	size_t resid;
	65	char *p;
	66	int r, ret;
	67	size_t total;
	68
	69	/*
1f2f436a	70	* ANSI and SUSv2 require a return value of 0 if size or count are 0.
34e8f829 A	71	*/
	72	if ((resid = count * size) == 0)
	73	return (0);
34e8f829 A	74	ORIENT(fp, -1);
	75	if (fp->_r < 0)
	76	fp->_r = 0;
	77	total = resid;
	78	p = buf;
	79	/* first deal with anything left in buffer, plus any ungetc buffers */
	80	while (resid > (r = fp->_r)) {
	81	(void)memcpy((void )p, (void )fp->_p, (size_t)r);
	82	fp->_p += r;
	83	/* fp->_r = 0 ... done in __srefill */
	84	p += r;
	85	resid -= r;
	86	if ((ret = __srefill0(fp)) > 0)
	87	break;
	88	else if (ret) {
	89	/* no more input: return partial result */
34e8f829 A	90	return ((total - resid) / size);
	91	}
	92	}
	93	/*
	94	* 5980080: don't use optimization if __SMBF not set (meaning setvbuf
	95	* was called, and the buffer belongs to the user).
	96	* 6180417: but for unbuffered (__SMBF is not set), so specifically
	97	* test for it.
	98	*/
	99	if ((fp->_flags & (__SMBF \| __SNBF)) && resid > fp->_bf._size) {
	100	struct __sbuf save;
	101	size_t n;
	102
	103	save = fp->_bf;
	104	fp->_bf._base = p;
	105	fp->_bf._size = resid;
	106	while (fp->_bf._size > 0) {
	107	if ((ret = __srefill1(fp)) != 0) {
	108	/* no more input: return partial result */
	109	resid = fp->_bf._size;
	110	fp->_bf = save;
	111	fp->_p = fp->_bf._base;
	112	/* fp->_r = 0; already set in __srefill1 */
34e8f829 A	113	return ((total - resid) / size);
	114	}
	115	fp->_bf._base += fp->_r;
	116	fp->_bf._size -= fp->_r;
	117	}
	118	fp->_bf = save;
	119	n = fp->_bf._size * ((resid - 1) / fp->_bf._size);
	120	r = resid - n;
	121	(void)memcpy((void )fp->_bf._base, (void )(p + n), (size_t)r);
	122	fp->_p = fp->_bf._base + r;
	123	fp->_r = 0;
	124	} else {
	125	while (resid > (r = fp->_r)) {
	126	(void)memcpy((void )p, (void )fp->_p, (size_t)r);
	127	fp->_p += r;
	128	/* fp->_r = 0 ... done in __srefill */
	129	p += r;
	130	resid -= r;
	131	if (__srefill1(fp)) {
	132	/* no more input: return partial result */
34e8f829 A	133	return ((total - resid) / size);
	134	}
	135	}
	136	(void)memcpy((void )p, (void )fp->_p, resid);
	137	fp->_r -= resid;
	138	fp->_p += resid;
	139	}
34e8f829 A	140	return (count);
34e8f829 A	141	}