xref: /openbmc/qemu/include/io/channel-buffer.h (revision db0f08df)
1 /*
2  * QEMU I/O channels memory buffer driver
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 #ifndef QIO_CHANNEL_BUFFER_H
22 #define QIO_CHANNEL_BUFFER_H
23 
24 #include "io/channel.h"
25 #include "qom/object.h"
26 
27 #define TYPE_QIO_CHANNEL_BUFFER "qio-channel-buffer"
28 OBJECT_DECLARE_SIMPLE_TYPE(QIOChannelBuffer, QIO_CHANNEL_BUFFER)
29 
30 
31 /**
32  * QIOChannelBuffer:
33  *
34  * The QIOChannelBuffer object provides a channel implementation
35  * that is able to perform I/O to/from a memory buffer.
36  *
37  */
38 
39 struct QIOChannelBuffer {
40     QIOChannel parent;
41     size_t capacity; /* Total allocated memory */
42     size_t usage;    /* Current size of data */
43     size_t offset;   /* Offset for future I/O ops */
44     uint8_t *data;
45 };
46 
47 
48 /**
49  * qio_channel_buffer_new:
50  * @capacity: the initial buffer capacity to allocate
51  *
52  * Allocate a new buffer which is initially empty
53  *
54  * Returns: the new channel object
55  */
56 QIOChannelBuffer *
57 qio_channel_buffer_new(size_t capacity);
58 
59 #endif /* QIO_CHANNEL_BUFFER_H */
60