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[/] [igor/] [trunk/] [avr/] [src/] [buf.c] - Blame information for rev 4

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#include "buf.h"
 
static uint16_t incptr(uint16_t);
static int8_t   buf_read_byte(struct buf *, uint8_t *);
static int8_t   buf_write_byte(struct buf *, uint8_t);
 
/* Common routines for buffer handling. */
void
buf_init(struct buf *buf)
{
        uint16_t i;
 
        for (i = 0; i < MAXBUFLEN; i++)
                buf->data[i] = 0;
        buf->off_read = 0;
        buf->off_write = 0;
        buf->wcount = 0;
        buf->rcount = 0;
        buf->status = BUF_STATUS_EMPTY;
}
 
static uint16_t
incptr(uint16_t val)
{
        return ((val + 1) % MAXBUFLEN);
}
 
/* Read from a circular buffer. */
static int8_t
buf_read_byte(struct buf *buf, uint8_t *data)
{
        /* No more data to read. */
        if (buf_readsleft(buf) == 0) {
                buf->status |= BUF_STATUS_EMPTY;
                return (-1);
        }
        *data = *(buf->data + buf->off_read);
        buf->off_read = incptr(buf->off_read);
        buf->rcount++;
        buf->status &= ~BUF_STATUS_FULL;
        return (0);
}
 
/*
 * Read many bytes from a buffer.
 * Assume data points to a buffer large enough to store num bytes.
 * Returns number of bytes read.
 */
int8_t
buf_read(struct buf *buf, uint8_t *data, uint8_t num)
{
        int8_t i;
 
        for (i = 0; i < num; i++)
                if (buf_read_byte(buf, (data + i)) != 0)
                        break;
        return (i);
}
 
/* Write to a circular buffer. */
static int8_t
buf_write_byte(struct buf *buf, uint8_t data)
{
        /* See if we have filled the buffer. */
        if (buf_writesleft(buf) == 0) {
                buf->status |= BUF_STATUS_FULL;
                return (-1);
        }
        *(buf->data + buf->off_write) = data;
        buf->off_write = incptr(buf->off_write);
        buf->wcount++;
        buf->status &= ~BUF_STATUS_EMPTY;
        return (0);
}
 
/*
 * Write many bytes to a buffer.
 * Assume data points to a buffer with num bytes to be sent.
 * Return number of bytes written.
 */
int8_t
buf_write(struct buf *buf, uint8_t *data, uint8_t num)
{
        uint8_t i;
 
        for (i = 0; i < num; i++)
                if (buf_write_byte(buf, *(data + i)) != 0)
                        break;
        return (i);
}
 
/* Returns number of buffers available for reading. */
uint16_t
buf_readsleft(struct buf *buf)
{
        return (buf->wcount > buf->rcount ?
            buf->wcount - buf->rcount :
            buf->rcount - buf->wcount);
}
 
/* Returns number of buffers available for writing. */
uint16_t
buf_writesleft(struct buf *buf)
{
        return (MAXBUFLEN - buf_readsleft(buf));
}

Line No.	Rev	Author	Line
1	4	atypic	`#include "buf.h"`
2
3			`static uint16_t incptr(uint16_t);`
4			`static int8_t buf_read_byte(struct buf , uint8_t );`
5			`static int8_t buf_write_byte(struct buf *, uint8_t);`
6
7			`/* Common routines for buffer handling. */`
8			`void`
9			`buf_init(struct buf *buf)`
10			`{`
11			`uint16_t i;`
12
13			`for (i = 0; i < MAXBUFLEN; i++)`
14			`buf->data[i] = 0;`
15			`buf->off_read = 0;`
16			`buf->off_write = 0;`
17			`buf->wcount = 0;`
18			`buf->rcount = 0;`
19			`buf->status = BUF_STATUS_EMPTY;`
20			`}`
21
22			`static uint16_t`
23			`incptr(uint16_t val)`
24			`{`
25			`return ((val + 1) % MAXBUFLEN);`
26			`}`
27
28			`/* Read from a circular buffer. */`
29			`static int8_t`
30			`buf_read_byte(struct buf buf, uint8_t data)`
31			`{`
32			`/* No more data to read. */`
33			`if (buf_readsleft(buf) == 0) {`
34			`buf->status \|= BUF_STATUS_EMPTY;`
35			`return (-1);`
36			`}`
37			`data = (buf->data + buf->off_read);`
38			`buf->off_read = incptr(buf->off_read);`
39			`buf->rcount++;`
40			`buf->status &= ~BUF_STATUS_FULL;`
41			`return (0);`
42			`}`
43
44			`/*`
45			`* Read many bytes from a buffer.`
46			`* Assume data points to a buffer large enough to store num bytes.`
47			`* Returns number of bytes read.`
48			`*/`
49			`int8_t`
50			`buf_read(struct buf buf, uint8_t data, uint8_t num)`
51			`{`
52			`int8_t i;`
53
54			`for (i = 0; i < num; i++)`
55			`if (buf_read_byte(buf, (data + i)) != 0)`
56			`break;`
57			`return (i);`
58			`}`
59
60			`/* Write to a circular buffer. */`
61			`static int8_t`
62			`buf_write_byte(struct buf *buf, uint8_t data)`
63			`{`
64			`/* See if we have filled the buffer. */`
65			`if (buf_writesleft(buf) == 0) {`
66			`buf->status \|= BUF_STATUS_FULL;`
67			`return (-1);`
68			`}`
69			`*(buf->data + buf->off_write) = data;`
70			`buf->off_write = incptr(buf->off_write);`
71			`buf->wcount++;`
72			`buf->status &= ~BUF_STATUS_EMPTY;`
73			`return (0);`
74			`}`
75
76			`/*`
77			`* Write many bytes to a buffer.`
78			`* Assume data points to a buffer with num bytes to be sent.`
79			`* Return number of bytes written.`
80			`*/`
81			`int8_t`
82			`buf_write(struct buf buf, uint8_t data, uint8_t num)`
83			`{`
84			`uint8_t i;`
85
86			`for (i = 0; i < num; i++)`
87			`if (buf_write_byte(buf, *(data + i)) != 0)`
88			`break;`
89			`return (i);`
90			`}`
91
92			`/* Returns number of buffers available for reading. */`
93			`uint16_t`
94			`buf_readsleft(struct buf *buf)`
95			`{`
96			`return (buf->wcount > buf->rcount ?`
97			`buf->wcount - buf->rcount :`
98			`buf->rcount - buf->wcount);`
99			`}`
100
101			`/* Returns number of buffers available for writing. */`
102			`uint16_t`
103			`buf_writesleft(struct buf *buf)`
104			`{`
105			`return (MAXBUFLEN - buf_readsleft(buf));`
106			`}`

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[/] [igor/] [trunk/] [avr/] [src/] [buf.c] - Blame information for rev 4