1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
|
#include <stdbool.h>
#include <stdint.h>
#include "types.h"
#include "can.h"
#include "eeprom.h"
#include "signal.h"
#include "serial.h"
#include "table.h"
Status
tabWrite(const Table *tab, U8 k, U32 key, U16 val) {
U16 addr;
U8 row[sizeof(key) + sizeof(val)];
if (k >= TAB_ROWS) {
return FAIL;
}
addr = tab->offset + k*TAB_ROW_SIZE;
serU32Be(row, key);
serU16Be(row+sizeof(key), val);
return eepromWrite(addr, row, sizeof(row));
}
Status
tabRead(const Table *tab, U8 k, U32 *key, U16 *val) {
U16 addr;
U8 row[sizeof(*key) + sizeof(*val)];
Status status;
if (k >= TAB_ROWS) {
return FAIL;
}
addr = tab->offset + k*TAB_ROW_SIZE;
status = eepromRead(addr, row, sizeof(row));
*key = deserU32Be(row);
*val = deserU16Be(row+sizeof(U32));
return status;
}
Status
tabLookup(const Table *tab, Number key, U16 *val) {
U8 k;
Number tkey;
U16 tval1, tval2;
Status status;
int ord;
// Search for key
for (k = 0u; (k < TAB_ROWS-1u); k++) {
status = tabRead(tab, k, &tkey.u32, &tval1);
if (status != OK) {
return FAIL;
}
status = u32ToNum(tkey.u32, key.type, &tkey);
if (status != OK) {
return FAIL;
}
status = cmpNum(key, tkey, &ord);
if (status != OK) {
return FAIL;
}
if (ord == 0) { // found exact key
*val = tval1;
return OK;
} else if (ord > 0) { // interpolate
status = tabRead(tab, k+1u, &tkey.u32, &tval2);
if (status != OK) {
return FAIL;
}
*val = (tval1 + tval2) / 2u;
return OK;
} else { // less
// continue
}
}
// Reached last row
*val = tval1; // last value in table
return OK;
}
|