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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 | */ | |
48 | int | |
002e1fde | 49 | __sfvwrite(LTTNG_UST_LFILE *fp, struct __lttng_ust_suio *uio) |
bf0d695d PMF |
50 | { |
51 | size_t len; | |
52 | char *p; | |
002e1fde | 53 | struct __lttng_ust_siov *iov; |
bf0d695d PMF |
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 | } |