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

/*	$OpenBSD: fvwrite.c,v 1.16 2009/10/22 01:23:16 guenther Exp $ */
/*-
 * 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.
 */

#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(LFILE *fp, struct __suio *uio)
{
	size_t len;
	char *p;
	struct __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 PMF	1	/* $OpenBSD: fvwrite.c,v 1.16 2009/10/22 01:23:16 guenther Exp $ */
	2	/*-
	3	* Copyright (c) 1990, 1993
	4	* The Regents of the University of California. All rights reserved.
	5	*
	6	* This code is derived from software contributed to Berkeley by
	7	* Chris Torek.
	8	*
	9	* Redistribution and use in source and binary forms, with or without
	10	* modification, are permitted provided that the following conditions
	11	* are met:
	12	* 1. Redistributions of source code must retain the above copyright
	13	* notice, this list of conditions and the following disclaimer.
	14	* 2. Redistributions in binary form must reproduce the above copyright
	15	* notice, this list of conditions and the following disclaimer in the
	16	* documentation and/or other materials provided with the distribution.
	17	* 3. Neither the name of the University nor the names of its contributors
	18	* may be used to endorse or promote products derived from this software
	19	* without specific prior written permission.
	20	*
	21	* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	22	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	23	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	24	* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	25	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	26	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	27	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	28	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	29	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	30	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	31	* SUCH DAMAGE.
	32	*/
	33
	34	#include <stdio.h>
	35	#include <stdlib.h>
	36	#include <string.h>
	37	#include <errno.h>
	38	#include "local.h"
	39	#include "fvwrite.h"
	40	#include "various.h"
	41
	42	/*
	43	* Write some memory regions. Return zero on success, EOF on error.
	44	*
	45	* This routine is large and unsightly, but most of the ugliness due
	46	* to the three different kinds of output buffering is handled here.
	47	*/
	48	int
	49	__sfvwrite(LFILE fp, struct __suio uio)
	50	{
	51	size_t len;
	52	char *p;
	53	struct __siov *iov;
	54	int w, s;
	55	char *nl;
	56	int nlknown, nldist;
	57
	58	if ((len = uio->uio_resid) == 0)
	59	return (0);
	60	/* make sure we can write */
	61	if (cantwrite(fp)) {
	62	errno = EBADF;
	63	return (EOF);
	64	}
65
66	#define MIN(a, b) ((a) < (b) ? (a) : (b))
67	#define COPY(n) (void)memcpy((void )fp->_p, (void )p, (size_t)(n))
68
69	iov = uio->uio_iov;
70	p = iov->iov_base;
71	len = iov->iov_len;
72	iov++;
73	#define GETIOV(extra_work) \
74	while (len == 0) { \
75	extra_work; \
76	p = iov->iov_base; \
77	len = iov->iov_len; \
78	iov++; \
79	}
80	if (fp->_flags & __SNBF) {
81	/*
82	* Unbuffered: write up to BUFSIZ bytes at a time.
83	*/
84	do {
85	GETIOV(;);
86	w = (*fp->_write)(fp->_cookie, p, MIN(len, BUFSIZ));
87	if (w <= 0)
88	goto err;
89	p += w;
90	len -= w;
91	} while ((uio->uio_resid -= w) != 0);
92	} else if ((fp->_flags & __SLBF) == 0) {
93	/*
94	* Fully buffered: fill partially full buffer, if any,
95	* and then flush. If there is no partial buffer, write
96	* one _bf._size byte chunk directly (without copying).
97	*
98	* String output is a special case: write as many bytes
99	* as fit, but pretend we wrote everything. This makes
100	* snprintf() return the number of bytes needed, rather
101	* than the number used, and avoids its write function
102	* (so that the write function can be invalid).
103	*/
104	do {
105	GETIOV(;);
106	if ((fp->_flags & (__SALC \| __SSTR)) ==
107	(__SALC \| __SSTR) && fp->_w < len) {
108	size_t blen = fp->_p - fp->_bf._base;
109	unsigned char *_base;
110	int _size;
111
112	/* Allocate space exponentially. */
113	_size = fp->_bf._size;
114	do {
115	_size = (_size << 1) + 1;
116	} while (_size < blen + len);
117	_base = realloc(fp->_bf._base, _size + 1);
118	if (_base == NULL)
119	goto err;
120	fp->_w += _size - fp->_bf._size;
121	fp->_bf._base = _base;
122	fp->_bf._size = _size;
123	fp->_p = _base + blen;
124	}
125	w = fp->_w;
126	if (fp->_flags & __SSTR) {
127	if (len < w)
128	w = len;
129	COPY(w); /* copy MIN(fp->_w,len), */
130	fp->_w -= w;
131	fp->_p += w;
132	w = len; /* but pretend copied all */
133	} else if (fp->_p > fp->_bf._base && len > w) {
134	/* fill and flush */
135	COPY(w);
136	/* fp->_w -= w; / / unneeded */
137	fp->_p += w;
138	if (ust_safe_fflush(fp))
139	goto err;
140	} else if (len >= (w = fp->_bf._size)) {
141	/* write directly */
142	w = (*fp->_write)(fp->_cookie, p, w);
143	if (w <= 0)
144	goto err;
145	} else {
146	/* fill and done */
147	w = len;
148	COPY(w);
149	fp->_w -= w;
150	fp->_p += w;
151	}
152	p += w;
153	len -= w;
154	} while ((uio->uio_resid -= w) != 0);
155	} else {
156	/*
157	* Line buffered: like fully buffered, but we
158	* must check for newlines. Compute the distance
159	* to the first newline (including the newline),
160	* or `infinity' if there is none, then pretend
161	* that the amount to write is MIN(len,nldist).
162	*/
163	nlknown = 0;
164	nldist = 0; /* XXX just to keep gcc happy */
165	do {
166	GETIOV(nlknown = 0);
167	if (!nlknown) {
168	nl = memchr((void *)p, '\n', len);
169	nldist = nl ? nl + 1 - p : len + 1;
170	nlknown = 1;
171	}
172	s = MIN(len, nldist);
173	w = fp->_w + fp->_bf._size;
174	if (fp->_p > fp->_bf._base && s > w) {
175	COPY(w);
176	/* fp->_w -= w; */
177	fp->_p += w;
178	if (ust_safe_fflush(fp))
179	goto err;
180	} else if (s >= (w = fp->_bf._size)) {
181	w = (*fp->_write)(fp->_cookie, p, w);
182	if (w <= 0)
183	goto err;
184	} else {
185	w = s;
186	COPY(w);
187	fp->_w -= w;
188	fp->_p += w;
189	}
190	if ((nldist -= w) == 0) {
191	/* copied the newline: flush and forget */
192	if (ust_safe_fflush(fp))
193	goto err;
194	nlknown = 0;
195	}
196	p += w;
197	len -= w;
198	} while ((uio->uio_resid -= w) != 0);
199	}
200	return (0);
201
202	err:
203	fp->_flags \|= __SERR;
204	return (EOF);
205	}