root / demos / hunter_prey / lib / src / libdragonfly / ring_buffer.h @ 1828
History | View | Annotate | Download (4.44 KB)
1 |
/**
|
---|---|
2 |
* Copyright (c) 2007 Colony Project
|
3 |
*
|
4 |
* Permission is hereby granted, free of charge, to any person
|
5 |
* obtaining a copy of this software and associated documentation
|
6 |
* files (the "Software"), to deal in the Software without
|
7 |
* restriction, including without limitation the rights to use,
|
8 |
* copy, modify, merge, publish, distribute, sublicense, and/or sell
|
9 |
* copies of the Software, and to permit persons to whom the
|
10 |
* Software is furnished to do so, subject to the following
|
11 |
* conditions:
|
12 |
*
|
13 |
* The above copyright notice and this permission notice shall be
|
14 |
* included in all copies or substantial portions of the Software.
|
15 |
*
|
16 |
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
|
17 |
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
|
18 |
* OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
|
19 |
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
|
20 |
* HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
|
21 |
* WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
|
22 |
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
|
23 |
* OTHER DEALINGS IN THE SOFTWARE.
|
24 |
**/
|
25 |
|
26 |
|
27 |
/** @file ring_buffer.h
|
28 |
* @brief Ring Buffer
|
29 |
*
|
30 |
* Include macros to create a ring buffer. Originally written for 15-410.
|
31 |
* Modified for use in ATMega128 serial driver
|
32 |
*
|
33 |
* @author Cornell Wright (cgwright)
|
34 |
* @author Jason P. Winters (jpwinter)
|
35 |
*
|
36 |
**/
|
37 |
|
38 |
#ifndef _RING_BUFFER_H
|
39 |
#define _RING_BUFFER_H
|
40 |
|
41 |
/** @brief Creates the struct for a new ring buffer. This just expands to a
|
42 |
* structure definition and thus should be invoked in the global context.
|
43 |
*
|
44 |
* @param struct_name Name of the ring buffer struct.
|
45 |
*
|
46 |
* @param size The size of the buffer to create.
|
47 |
*
|
48 |
* @param type The type of object that the queue is to hold.
|
49 |
*
|
50 |
* @param ... Name or names of the instance or instances of the ring buffer(s)
|
51 |
* to be created.
|
52 |
*/
|
53 |
#define RING_BUFFER_NEW(struct_name, size, type, ...) \
|
54 |
struct struct_name { \
|
55 |
type queue[size]; \ |
56 |
uint8_t start; \ |
57 |
uint8_t end; \ |
58 |
uint8_t buffer_size; \ |
59 |
} __VA_ARGS__ |
60 |
|
61 |
|
62 |
/** @brief Initializes the ring buffer, setting its size to the correct value
|
63 |
*
|
64 |
* @param buf The ring buffer to initialize.
|
65 |
*
|
66 |
* @param size The size of the ring buffer (in array elements)
|
67 |
*/
|
68 |
#define RING_BUFFER_INIT(buf, size) \
|
69 |
do { \
|
70 |
(buf).buffer_size = size; \ |
71 |
} while(0) |
72 |
|
73 |
|
74 |
/** @brief Sets the specified ring buffer to be empty.
|
75 |
*
|
76 |
* @param buf The ring buffer to make empty.
|
77 |
*/
|
78 |
#define RING_BUFFER_CLEAR(buf) \
|
79 |
do { \
|
80 |
(buf).start = 0; \
|
81 |
(buf).end = 0; \
|
82 |
} while (0) |
83 |
|
84 |
/** @brief Returns true if the ring buffer specified is empty.
|
85 |
*
|
86 |
* @param buf The buffer to check emptiness of.
|
87 |
*/
|
88 |
#define RING_BUFFER_EMPTY(buf) ((buf).start == (buf).end)
|
89 |
|
90 |
|
91 |
/** @brief Returns true if the ring buffer specified is full.
|
92 |
*
|
93 |
* @param buf The buffer to check fullness of.
|
94 |
*/
|
95 |
#define RING_BUFFER_FULL(buf) \
|
96 |
(((buf).end + 1) % (buf).buffer_size == (buf).start)
|
97 |
|
98 |
|
99 |
/** @brief Adds val to ring buffer buf. Note that val must be of the type
|
100 |
* used in creating the ring buffer to prevent the compiler from spewing
|
101 |
* confusing errors. Also, this assumes that the ring buffer is not full.
|
102 |
*
|
103 |
* @param buf The ring buffer to add to.
|
104 |
* @param val The value to add.
|
105 |
*/
|
106 |
#define RING_BUFFER_ADD(buf, val) \
|
107 |
do { \
|
108 |
(buf).queue[(buf).end] = val; \ |
109 |
(buf).end = ((buf).end + 1) % (buf).buffer_size; \
|
110 |
} while (0) |
111 |
|
112 |
|
113 |
/** @brief Removes the value at the head of the ring buffer and puts it in
|
114 |
* val_ret. Note that val_ret must be the same type used in creating the ring
|
115 |
* buffer to prevent the compiler from spewing confusing errors. Also, this
|
116 |
* assumes that the ring buffer is not empty.
|
117 |
*
|
118 |
* @param buf The ring buffer to remove from.
|
119 |
* @param val_ret Where to put the value removed from the head of the ring
|
120 |
* buffer.
|
121 |
*/
|
122 |
#define RING_BUFFER_REMOVE(buf, val_ret) \
|
123 |
do { \
|
124 |
(val_ret) = (buf).queue[(buf).start]; \ |
125 |
(buf).start = ((buf).start + 1) % (buf).buffer_size; \
|
126 |
} while (0) |
127 |
|
128 |
/** @brief Checks the value at the head of the ring buffer without removing it
|
129 |
* and puts it into val_ret. Note that val_ret must be the same type used in
|
130 |
* creating the ring buffer to prevent the compiler from spewing confusing
|
131 |
* errors. Also, this assumes that the ring buffer is not empty.
|
132 |
*
|
133 |
* @param buf The ring buffer to check from
|
134 |
* @param val_ret where to put the value checked from the head of the ring
|
135 |
*/
|
136 |
#define RING_BUFFER_PEEK(buf, val_ret) \
|
137 |
do { \
|
138 |
(val_ret) = (buf).queue[(buf).start]; \ |
139 |
} while(0) |
140 |
|
141 |
#endif /* _RING_BUFFER_H */ |
142 |
|