xref: /openbmc/qemu/util/buffer.c (revision 56411125)
1 /*
2  * QEMU generic buffers
3  *
4  * Copyright (c) 2015 Red Hat, Inc.
5  *
6  * This library is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2 of the License, or (at your option) any later version.
10  *
11  * This library is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
18  *
19  */
20 
21 #include "qemu/buffer.h"
22 
23 void buffer_reserve(Buffer *buffer, size_t len)
24 {
25     if ((buffer->capacity - buffer->offset) < len) {
26         buffer->capacity += (len + 1024);
27         buffer->buffer = g_realloc(buffer->buffer, buffer->capacity);
28     }
29 }
30 
31 gboolean buffer_empty(Buffer *buffer)
32 {
33     return buffer->offset == 0;
34 }
35 
36 uint8_t *buffer_end(Buffer *buffer)
37 {
38     return buffer->buffer + buffer->offset;
39 }
40 
41 void buffer_reset(Buffer *buffer)
42 {
43     buffer->offset = 0;
44 }
45 
46 void buffer_free(Buffer *buffer)
47 {
48     g_free(buffer->buffer);
49     buffer->offset = 0;
50     buffer->capacity = 0;
51     buffer->buffer = NULL;
52 }
53 
54 void buffer_append(Buffer *buffer, const void *data, size_t len)
55 {
56     memcpy(buffer->buffer + buffer->offset, data, len);
57     buffer->offset += len;
58 }
59 
60 void buffer_advance(Buffer *buffer, size_t len)
61 {
62     memmove(buffer->buffer, buffer->buffer + len,
63             (buffer->offset - len));
64     buffer->offset -= len;
65 }
66