Line No. | Rev | Author | Line |
---|---|---|---|
1 | 6 | kaklik | /*! \file buffer.c \brief Multipurpose byte buffer structure and methods. */ |
2 | //***************************************************************************** |
||
3 | // |
||
4 | // File Name : 'buffer.c' |
||
5 | // Title : Multipurpose byte buffer structure and methods |
||
6 | // Author : Pascal Stang - Copyright (C) 2001-2002 |
||
7 | // Created : 9/23/2001 |
||
8 | // Revised : 9/23/2001 |
||
9 | // Version : 1.0 |
||
10 | // Target MCU : any |
||
11 | // Editor Tabs : 4 |
||
12 | // |
||
13 | // This code is distributed under the GNU Public License |
||
14 | // which can be found at http://www.gnu.org/licenses/gpl.txt |
||
15 | // |
||
16 | //***************************************************************************** |
||
17 | |||
18 | #include "buffer.h" |
||
19 | #include "global.h" |
||
20 | #include "avr/io.h" |
||
21 | |||
22 | #ifndef CRITICAL_SECTION_START |
||
23 | #define CRITICAL_SECTION_START unsigned char _sreg = SREG; cli() |
||
24 | #define CRITICAL_SECTION_END SREG = _sreg |
||
25 | #endif |
||
26 | |||
27 | // global variables |
||
28 | |||
29 | // initialization |
||
30 | |||
31 | void bufferInit(cBuffer* buffer, unsigned char *start, unsigned short size) |
||
32 | { |
||
33 | // begin critical section |
||
34 | CRITICAL_SECTION_START; |
||
35 | // set start pointer of the buffer |
||
36 | buffer->dataptr = start; |
||
37 | buffer->size = size; |
||
38 | // initialize index and length |
||
39 | buffer->dataindex = 0; |
||
40 | buffer->datalength = 0; |
||
41 | // end critical section |
||
42 | CRITICAL_SECTION_END; |
||
43 | } |
||
44 | |||
45 | // access routines |
||
46 | unsigned char bufferGetFromFront(cBuffer* buffer) |
||
47 | { |
||
48 | unsigned char data = 0; |
||
49 | // begin critical section |
||
50 | CRITICAL_SECTION_START; |
||
51 | // check to see if there's data in the buffer |
||
52 | if(buffer->datalength) |
||
53 | { |
||
54 | // get the first character from buffer |
||
55 | data = buffer->dataptr[buffer->dataindex]; |
||
56 | // move index down and decrement length |
||
57 | buffer->dataindex++; |
||
58 | if(buffer->dataindex >= buffer->size) |
||
59 | { |
||
60 | buffer->dataindex -= buffer->size; |
||
61 | } |
||
62 | buffer->datalength--; |
||
63 | } |
||
64 | // end critical section |
||
65 | CRITICAL_SECTION_END; |
||
66 | // return |
||
67 | return data; |
||
68 | } |
||
69 | |||
70 | void bufferDumpFromFront(cBuffer* buffer, unsigned short numbytes) |
||
71 | { |
||
72 | // begin critical section |
||
73 | CRITICAL_SECTION_START; |
||
74 | // dump numbytes from the front of the buffer |
||
75 | // are we dumping less than the entire buffer? |
||
76 | if(numbytes < buffer->datalength) |
||
77 | { |
||
78 | // move index down by numbytes and decrement length by numbytes |
||
79 | buffer->dataindex += numbytes; |
||
80 | if(buffer->dataindex >= buffer->size) |
||
81 | { |
||
82 | buffer->dataindex -= buffer->size; |
||
83 | } |
||
84 | buffer->datalength -= numbytes; |
||
85 | } |
||
86 | else |
||
87 | { |
||
88 | // flush the whole buffer |
||
89 | buffer->datalength = 0; |
||
90 | } |
||
91 | // end critical section |
||
92 | CRITICAL_SECTION_END; |
||
93 | } |
||
94 | |||
95 | unsigned char bufferGetAtIndex(cBuffer* buffer, unsigned short index) |
||
96 | { |
||
97 | // begin critical section |
||
98 | CRITICAL_SECTION_START; |
||
99 | // return character at index in buffer |
||
100 | unsigned char data = buffer->dataptr[(buffer->dataindex+index)%(buffer->size)]; |
||
101 | // end critical section |
||
102 | CRITICAL_SECTION_END; |
||
103 | return data; |
||
104 | } |
||
105 | |||
106 | unsigned char bufferAddToEnd(cBuffer* buffer, unsigned char data) |
||
107 | { |
||
108 | // begin critical section |
||
109 | CRITICAL_SECTION_START; |
||
110 | // make sure the buffer has room |
||
111 | if(buffer->datalength < buffer->size) |
||
112 | { |
||
113 | // save data byte at end of buffer |
||
114 | buffer->dataptr[(buffer->dataindex + buffer->datalength) % buffer->size] = data; |
||
115 | // increment the length |
||
116 | buffer->datalength++; |
||
117 | // end critical section |
||
118 | CRITICAL_SECTION_END; |
||
119 | // return success |
||
120 | return -1; |
||
121 | } |
||
122 | // end critical section |
||
123 | CRITICAL_SECTION_END; |
||
124 | // return failure |
||
125 | return 0; |
||
126 | } |
||
127 | |||
128 | unsigned short bufferIsNotFull(cBuffer* buffer) |
||
129 | { |
||
130 | // begin critical section |
||
131 | CRITICAL_SECTION_START; |
||
132 | // check to see if the buffer has room |
||
133 | // return true if there is room |
||
134 | unsigned short bytesleft = (buffer->size - buffer->datalength); |
||
135 | // end critical section |
||
136 | CRITICAL_SECTION_END; |
||
137 | return bytesleft; |
||
138 | } |
||
139 | |||
140 | void bufferFlush(cBuffer* buffer) |
||
141 | { |
||
142 | // begin critical section |
||
143 | CRITICAL_SECTION_START; |
||
144 | // flush contents of the buffer |
||
145 | buffer->datalength = 0; |
||
146 | // end critical section |
||
147 | CRITICAL_SECTION_END; |
||
148 | } |
||
149 |
Powered by WebSVN v2.8.3