Update version to 0.16
[ust.git] / snprintf / fvwrite.c
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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 */
48int
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
202err:
203 fp->_flags |= __SERR;
204 return (EOF);
205}
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