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#include <stdbool.h>
#include <stdint.h>
#include "types.h"
#include "can.h"
#include "eeprom.h"
#include "table.h"
Status
tabWrite(const Table *tab, U8 k, U16 key, U16 val) {
if (k >= TAB_ROWS) {
return FAIL;
}
U16 addr = tab->offset + k*TAB_ROW_SIZE;
U8 row[4u] = {
(key>>0u)&0xFF, (key>>8u)&0xFF,
(val>>0u)&0xFF, (val>>8u)&0xFF};
return eepromWrite(addr, row, sizeof(row));
}
Status
tabRead(const Table *tab, U8 k, U16 *key, U16 *val) {
U16 addr;
U8 row[4u];
Status status;
if (k >= TAB_ROWS) {
return FAIL;
}
addr = tab->offset + k*TAB_ROW_SIZE;
status = eepromRead(addr, row, sizeof(row));
*key = ((U16)row[0u]<<0u) | ((U16)row[1u]<<8u);
*val = ((U16)row[2u]<<0u) | ((U16)row[3u]<<8u);
return status;
}
Status
tabLookup(const Table *tab, U16 key, U16 *val) {
U8 k;
U16 tkey, tval1, tval2;
Status status;
// Search for key
for (k = 0u; (k < TAB_ROWS-1u); k++) {
status = tabRead(tab, k, &tkey, &tval1);
if (status != OK) {
return FAIL;
}
if (key == tkey) { // found exact key
*val = tval1;
return OK;
} else if (key > tkey) { // interpolate
status = tabRead(tab, k+1u, &tkey, &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;
}
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