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#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 row;
Number tkey1, tkey2;
U16 tval1, tval2;
Status status;
int ord;
// Search for key
for (row = 0u; row < (TAB_ROWS-1u); row++) {
status = tabRead(tab, row, &tkey1.u32, &tval1);
if (status != OK) {
return FAIL;
}
status = u32ToNum(tkey1.u32, key.type, &tkey1);
if (status != OK) {
return FAIL;
}
status = cmpNum(key, tkey1, &ord);
if (status != OK) {
return FAIL;
}
if (ord == 0) { // found exact key
*val = tval1;
return OK;
} else if (ord < 0) { // key < tkey
if (row > 0u) { // not first row
// Interpolate with previous row
status = tabRead(tab, row-1u, &tkey2.u32, &tval2);
if (status != OK) {
return FAIL;
}
status = u32ToNum(tkey2.u32, key.type, &tkey2);
if (status != OK) {
return FAIL;
}
*val = (tval1 + tval2) / 2u; // TODO: linear interpolation
} else { // key < key of first row
*val = tval1; // use first row value
}
return OK;
} else { // key > tkey
// continue until key <= tkey
}
}
// Reached last row
*val = tval1; // last value in table
return OK;
}
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