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
|
/* buffer.c
*
* Wiretap Library
* Copyright (c) 1998 by Gilbert Ramirez <gram@alumni.rice.edu>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*
*/
#include "config.h"
#include <stdlib.h>
#include <string.h>
#include "buffer.h"
/* Initializes a buffer with a certain amount of allocated space */
void
ws_buffer_init(Buffer* buffer, gsize space)
{
buffer->data = (guint8*)g_malloc(space);
buffer->allocated = space;
buffer->start = 0;
buffer->first_free = 0;
}
/* Frees the memory used by a buffer */
void
ws_buffer_free(Buffer* buffer)
{
g_free(buffer->data);
buffer->data = NULL;
}
/* Assures that there are 'space' bytes at the end of the used space
so that another routine can copy directly into the buffer space. After
doing that, the routine will also want to run
ws_buffer_increase_length(). */
void
ws_buffer_assure_space(Buffer* buffer, gsize space)
{
gsize available_at_end = buffer->allocated - buffer->first_free;
gsize space_used;
gboolean space_at_beginning;
/* If we've got the space already, good! */
if (space <= available_at_end) {
return;
}
/* Maybe we don't have the space available at the end, but we would
if we moved the used space back to the beginning of the
allocation. The buffer could have become fragmented through lots
of calls to ws_buffer_remove_start(). I'm using buffer->start as the
same as 'available_at_start' in this comparison. */
/* or maybe there's just no more room. */
space_at_beginning = buffer->start >= space;
if (space_at_beginning || buffer->start > 0) {
space_used = buffer->first_free - buffer->start;
/* this memory copy better be safe for overlapping memory regions! */
memmove(buffer->data, buffer->data + buffer->start, space_used);
buffer->start = 0;
buffer->first_free = space_used;
}
/*if (buffer->start >= space) {*/
if (space_at_beginning) {
return;
}
/* We'll allocate more space */
buffer->allocated += space + 1024;
buffer->data = (guint8*)g_realloc(buffer->data, buffer->allocated);
}
void
ws_buffer_append(Buffer* buffer, guint8 *from, gsize bytes)
{
ws_buffer_assure_space(buffer, bytes);
memcpy(buffer->data + buffer->first_free, from, bytes);
buffer->first_free += bytes;
}
void
ws_buffer_remove_start(Buffer* buffer, gsize bytes)
{
if (buffer->start + bytes > buffer->first_free) {
g_error("ws_buffer_remove_start trying to remove %" G_GINT64_MODIFIER "u bytes. s=%" G_GINT64_MODIFIER "u ff=%" G_GINT64_MODIFIER "u!\n",
(guint64)bytes, (guint64)buffer->start,
(guint64)buffer->first_free);
/** g_error() does an abort() and thus never returns **/
}
buffer->start += bytes;
if (buffer->start == buffer->first_free) {
buffer->start = 0;
buffer->first_free = 0;
}
}
#ifndef SOME_FUNCTIONS_ARE_DEFINES
void
ws_buffer_clean(Buffer* buffer)
{
ws_buffer_remove_start(buffer, ws_buffer_length(buffer));
}
#endif
#ifndef SOME_FUNCTIONS_ARE_DEFINES
void
ws_buffer_increase_length(Buffer* buffer, gsize bytes)
{
buffer->first_free += bytes;
}
#endif
#ifndef SOME_FUNCTIONS_ARE_DEFINES
gsize
ws_buffer_length(Buffer* buffer)
{
return buffer->first_free - buffer->start;
}
#endif
#ifndef SOME_FUNCTIONS_ARE_DEFINES
guint8 *
ws_buffer_start_ptr(Buffer* buffer)
{
return buffer->data + buffer->start;
}
#endif
#ifndef SOME_FUNCTIONS_ARE_DEFINES
guint8 *
ws_buffer_end_ptr(Buffer* buffer)
{
return buffer->data + buffer->first_free;
}
#endif
#ifndef SOME_FUNCTIONS_ARE_DEFINES
void
ws_buffer_append_buffer(Buffer* buffer, Buffer* src_buffer)
{
ws_buffer_append(buffer, ws_buffer_start_ptr(src_buffer), ws_buffer_length(src_buffer));
}
#endif
/*
* Editor modelines - http://www.wireshark.org/tools/modelines.html
*
* Local variables:
* c-basic-offset: 8
* tab-width: 8
* indent-tabs-mode: t
* End:
*
* vi: set shiftwidth=8 tabstop=8 noexpandtab:
* :indentSize=8:tabSize=8:noTabs=false:
*/
|
