[lttng-ust.git] / snprintf / fvwrite.c

/*	$OpenBSD: fvwrite.c,v 1.16 2009/10/22 01:23:16 guenther Exp $ */
/*
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * 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.
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include "local.h"
#include "fvwrite.h"
#include "various.h"

/*
 * Write some memory regions.  Return zero on success, EOF on error.
 *
 * This routine is large and unsightly, but most of the ugliness due
 * to the three different kinds of output buffering is handled here.
 */
int
__sfvwrite(LTTNG_UST_LFILE *fp, struct __lttng_ust_suio *uio)
{
	size_t len;
	char *p;
	struct __lttng_ust_siov *iov;
	int w, s;
	char *nl;
	int nlknown, nldist;

	if ((len = uio->uio_resid) == 0)
		return (0);
	/* make sure we can write */
	if (cantwrite(fp)) {
		errno = EBADF;
		return (EOF);
	}

#define	MIN(a, b) ((a) < (b) ? (a) : (b))
#define	COPY(n)	  (void)memcpy((void *)fp->_p, (void *)p, (size_t)(n))

	iov = uio->uio_iov;
	p = iov->iov_base;
	len = iov->iov_len;
	iov++;
#define GETIOV(extra_work) \
	while (len == 0) { \
		extra_work; \
		p = iov->iov_base; \
		len = iov->iov_len; \
		iov++; \
	}
	if (fp->_flags & __SNBF) {
		/*
		 * Unbuffered: write up to BUFSIZ bytes at a time.
		 */
		do {
			GETIOV(;);
			w = (*fp->_write)(fp->_cookie, p, MIN(len, BUFSIZ));
			if (w <= 0)
				goto err;
			p += w;
			len -= w;
		} while ((uio->uio_resid -= w) != 0);
	} else if ((fp->_flags & __SLBF) == 0) {
		/*
		 * Fully buffered: fill partially full buffer, if any,
		 * and then flush.  If there is no partial buffer, write
		 * one _bf._size byte chunk directly (without copying).
		 *
		 * String output is a special case: write as many bytes
		 * as fit, but pretend we wrote everything.  This makes
		 * snprintf() return the number of bytes needed, rather
		 * than the number used, and avoids its write function
		 * (so that the write function can be invalid).
		 */
		do {
			GETIOV(;);
			if ((fp->_flags & (__SALC | __SSTR)) ==
			    (__SALC | __SSTR) && fp->_w < len) {
				size_t blen = fp->_p - fp->_bf._base;
				unsigned char *_base;
				int _size;

				/* Allocate space exponentially. */
				_size = fp->_bf._size;
				do {
					_size = (_size << 1) + 1;
				} while (_size < blen + len);
				_base = realloc(fp->_bf._base, _size + 1);
				if (_base == NULL)
					goto err;
				fp->_w += _size - fp->_bf._size;
				fp->_bf._base = _base;
				fp->_bf._size = _size;
				fp->_p = _base + blen;
			}
			w = fp->_w;
			if (fp->_flags & __SSTR) {
				if (len < w)
					w = len;
				COPY(w);	/* copy MIN(fp->_w,len), */
				fp->_w -= w;
				fp->_p += w;
				w = len;	/* but pretend copied all */
			} else if (fp->_p > fp->_bf._base && len > w) {
				/* fill and flush */
				COPY(w);
				/* fp->_w -= w; */ /* unneeded */
				fp->_p += w;
				if (ust_safe_fflush(fp))
					goto err;
			} else if (len >= (w = fp->_bf._size)) {
				/* write directly */
				w = (*fp->_write)(fp->_cookie, p, w);
				if (w <= 0)
					goto err;
			} else {
				/* fill and done */
				w = len;
				COPY(w);
				fp->_w -= w;
				fp->_p += w;
			}
			p += w;
			len -= w;
		} while ((uio->uio_resid -= w) != 0);
	} else {
		/*
		 * Line buffered: like fully buffered, but we
		 * must check for newlines.  Compute the distance
		 * to the first newline (including the newline),
		 * or `infinity' if there is none, then pretend
		 * that the amount to write is MIN(len,nldist).
		 */
		nlknown = 0;
		nldist = 0;	/* XXX just to keep gcc happy */
		do {
			GETIOV(nlknown = 0);
			if (!nlknown) {
				nl = memchr((void *)p, '\n', len);
				nldist = nl ? nl + 1 - p : len + 1;
				nlknown = 1;
			}
			s = MIN(len, nldist);
			w = fp->_w + fp->_bf._size;
			if (fp->_p > fp->_bf._base && s > w) {
				COPY(w);
				/* fp->_w -= w; */
				fp->_p += w;
				if (ust_safe_fflush(fp))
					goto err;
			} else if (s >= (w = fp->_bf._size)) {
				w = (*fp->_write)(fp->_cookie, p, w);
				if (w <= 0)
				 	goto err;
			} else {
				w = s;
				COPY(w);
				fp->_w -= w;
				fp->_p += w;
			}
			if ((nldist -= w) == 0) {
				/* copied the newline: flush and forget */
				if (ust_safe_fflush(fp))
					goto err;
				nlknown = 0;
			}
			p += w;
			len -= w;
		} while ((uio->uio_resid -= w) != 0);
	}
	return (0);

err:
	fp->_flags |= __SERR;
	return (EOF);
}
Commit	Line	Data
bf0d695d	1	/* $OpenBSD: fvwrite.c,v 1.16 2009/10/22 01:23:16 guenther Exp $ */
c0c0989a MJ	2	/*
	3	* SPDX-License-Identifier: BSD-3-Clause
	4	*
	5	* Copyright (C) 1990, 1993
bf0d695d PMF	6	* The Regents of the University of California. All rights reserved.
	7	*
	8	* This code is derived from software contributed to Berkeley by
	9	* Chris Torek.
bf0d695d PMF	10	*/
	11
	12	#include <stdio.h>
	13	#include <stdlib.h>
	14	#include <string.h>
	15	#include <errno.h>
	16	#include "local.h"
	17	#include "fvwrite.h"
	18	#include "various.h"
	19
	20	/*
	21	* Write some memory regions. Return zero on success, EOF on error.
	22	*
	23	* This routine is large and unsightly, but most of the ugliness due
	24	* to the three different kinds of output buffering is handled here.
	25	*/
	26	int
002e1fde	27	__sfvwrite(LTTNG_UST_LFILE fp, struct __lttng_ust_suio uio)
bf0d695d PMF	28	{
	29	size_t len;
	30	char *p;
002e1fde	31	struct __lttng_ust_siov *iov;
bf0d695d PMF	32	int w, s;
	33	char *nl;
	34	int nlknown, nldist;
	35
	36	if ((len = uio->uio_resid) == 0)
	37	return (0);
	38	/* make sure we can write */
	39	if (cantwrite(fp)) {
	40	errno = EBADF;
	41	return (EOF);
	42	}
	43
	44	#define MIN(a, b) ((a) < (b) ? (a) : (b))
	45	#define COPY(n) (void)memcpy((void )fp->_p, (void )p, (size_t)(n))
	46
	47	iov = uio->uio_iov;
	48	p = iov->iov_base;
	49	len = iov->iov_len;
	50	iov++;
	51	#define GETIOV(extra_work) \
	52	while (len == 0) { \
	53	extra_work; \
	54	p = iov->iov_base; \
	55	len = iov->iov_len; \
	56	iov++; \
	57	}
	58	if (fp->_flags & __SNBF) {
	59	/*
	60	* Unbuffered: write up to BUFSIZ bytes at a time.
	61	*/
	62	do {
	63	GETIOV(;);
	64	w = (*fp->_write)(fp->_cookie, p, MIN(len, BUFSIZ));
	65	if (w <= 0)
	66	goto err;
	67	p += w;
	68	len -= w;
	69	} while ((uio->uio_resid -= w) != 0);
	70	} else if ((fp->_flags & __SLBF) == 0) {
	71	/*
	72	* Fully buffered: fill partially full buffer, if any,
	73	* and then flush. If there is no partial buffer, write
	74	* one _bf._size byte chunk directly (without copying).
	75	*
	76	* String output is a special case: write as many bytes
	77	* as fit, but pretend we wrote everything. This makes
	78	* snprintf() return the number of bytes needed, rather
	79	* than the number used, and avoids its write function
	80	* (so that the write function can be invalid).
	81	*/
	82	do {
	83	GETIOV(;);
	84	if ((fp->_flags & (__SALC \| __SSTR)) ==
	85	(__SALC \| __SSTR) && fp->_w < len) {
	86	size_t blen = fp->_p - fp->_bf._base;
	87	unsigned char *_base;
	88	int _size;
	89
	90	/* Allocate space exponentially. */
	91	_size = fp->_bf._size;
	92	do {
	93	_size = (_size << 1) + 1;
	94	} while (_size < blen + len);
	95	_base = realloc(fp->_bf._base, _size + 1);
96	if (_base == NULL)
97	goto err;
98	fp->_w += _size - fp->_bf._size;
99	fp->_bf._base = _base;
100	fp->_bf._size = _size;
101	fp->_p = _base + blen;
102	}
103	w = fp->_w;
104	if (fp->_flags & __SSTR) {
105	if (len < w)
106	w = len;
107	COPY(w); /* copy MIN(fp->_w,len), */
108	fp->_w -= w;
109	fp->_p += w;
110	w = len; /* but pretend copied all */
111	} else if (fp->_p > fp->_bf._base && len > w) {
112	/* fill and flush */
113	COPY(w);
114	/* fp->_w -= w; / / unneeded */
115	fp->_p += w;
116	if (ust_safe_fflush(fp))
117	goto err;
118	} else if (len >= (w = fp->_bf._size)) {
119	/* write directly */
120	w = (*fp->_write)(fp->_cookie, p, w);
121	if (w <= 0)
122	goto err;
123	} else {
124	/* fill and done */
125	w = len;
126	COPY(w);
127	fp->_w -= w;
128	fp->_p += w;
129	}
130	p += w;
131	len -= w;
132	} while ((uio->uio_resid -= w) != 0);
133	} else {
134	/*
135	* Line buffered: like fully buffered, but we
136	* must check for newlines. Compute the distance
137	* to the first newline (including the newline),
138	* or `infinity' if there is none, then pretend
139	* that the amount to write is MIN(len,nldist).
140	*/
141	nlknown = 0;
142	nldist = 0; /* XXX just to keep gcc happy */
143	do {
144	GETIOV(nlknown = 0);
145	if (!nlknown) {
146	nl = memchr((void *)p, '\n', len);
147	nldist = nl ? nl + 1 - p : len + 1;
148	nlknown = 1;
149	}
150	s = MIN(len, nldist);
151	w = fp->_w + fp->_bf._size;
152	if (fp->_p > fp->_bf._base && s > w) {
153	COPY(w);
154	/* fp->_w -= w; */
155	fp->_p += w;
156	if (ust_safe_fflush(fp))
157	goto err;
158	} else if (s >= (w = fp->_bf._size)) {
159	w = (*fp->_write)(fp->_cookie, p, w);
160	if (w <= 0)
161	goto err;
162	} else {
163	w = s;
164	COPY(w);
165	fp->_w -= w;
166	fp->_p += w;
167	}
168	if ((nldist -= w) == 0) {
169	/* copied the newline: flush and forget */
170	if (ust_safe_fflush(fp))
171	goto err;
172	nlknown = 0;
173	}
174	p += w;
175	len -= w;
176	} while ((uio->uio_resid -= w) != 0);
177	}
178	return (0);
179
180	err:
181	fp->_flags \|= __SERR;
182	return (EOF);
183	}