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
|
/*
* Copyright (c) 2000-2001
* The Regents of the University of California. All rights reserved.
*
* 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 <assert.h>
#include <stdio.h>
#include <string.h>
#include "buffer.h"
/* Invariant: buffer always null-terminated */
struct growbuf
{
region r;
unsigned int maxsize, cursize;
char *buffer;
};
/* Make a new buffer with initial size */
growbuf growbuf_new(region r, int size)
{
growbuf b = ralloc(r, struct growbuf);
assert(size > 0);
b->r = r;
b->maxsize = size; /* Force some growth! */
b->cursize = 1;
b->buffer = rstralloc(r, size);
b->buffer[0] = '\0';
return b;
}
/* Empty a buffer */
void growbuf_reset(growbuf b)
{
assert(b->maxsize > 0);
b->cursize = 1;
b->buffer[0] = '\0';
}
/* Print to a buffer */
int gprintf(growbuf b, const char *fmt, ...)
{
va_list args;
va_start(args, fmt);
return gvprintf(b, fmt, args);
}
/* Print to a buffer */
int gvprintf(growbuf b, const char *fmt, va_list args)
{
int nchars;
if (!fmt) /* Bug (?)/feature of vnsprintf -- printing \0 returns -1,
goes into infinite loop. */
return 0;
while (1)
{
char *bufStart;
int sizeLeft;
bufStart = b->buffer + b->cursize - 1; /* chop trailing \0 */
sizeLeft = b->maxsize - b->cursize + 1; /* +1 size we're chooping
the trailing \0 */
assert(*bufStart == '\0');
nchars = vsnprintf(bufStart, sizeLeft, fmt, args);
if (nchars > -1 && nchars < sizeLeft)
{
b->cursize += nchars; /* nchars doesn't include \0,
but we overwrote our \0 */
break;
}
else
{
/* How much room do we need? In the new glibc, nchars
tells us how much (not including the trailing null).
So we need the current size, -1 since we'll remove the null,
plus the new size, plus 1 for the new null. */
int newSize = (nchars > -1) ? b->cursize - 1 + nchars + 1
: b->maxsize * 2;
char *newBuf;
/* fprintf(stderr, "Reallocating buffer, newSize=%d\n", newSize); */
newBuf = rstralloc(b->r, newSize);
memcpy(newBuf, b->buffer, b->cursize);
newBuf[b->cursize-1] = '\0'; /* vsnprintf has printed something! */
b->buffer = newBuf;
b->maxsize = newSize;
/* b->cursize unchanged */
}
}
return nchars;
}
/* Get the contents of a buffer */
char *growbuf_contents(growbuf b)
{
return b->buffer;
}
bool growbuf_empty(growbuf b)
{
return b->cursize == 1; /* Buffer always null terminated */
}
|
