1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
|
/* $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(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);
}
|
