efilib.cpp

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/**
 * @file    efilib.cpp
 *
 * We cannot use stdlib because we do not have malloc - so, we have to implement these functions
 *
 * @date Feb 21, 2014
 * @author Andrey Belomutskiy, (c) 2012-2020
 */
 
#include "pch.h"
 
#include <cstring>
#include <cctype>
#include <cmath>
#include "datalogging.h"
#include "histogram.h"
 
// also known as bool2string and boolean2string
const char * boolToString(bool value) {
    return value ? "Yes" : "No";
}
 
/*
float efiFloor(float value, float precision) {
    int a = (int) (value / precision);
    return a * precision;
}
*/
 
/**
 *
 * @param precision for example '0.1' for one digit fractional part
 */
float efiRound(float value, float precision) {
    efiAssert(ObdCode::CUSTOM_ERR_ASSERT, precision != 0, "Zero precision is not valid for efiRound maybe you mean '1'?", NAN);
    float a = round(value / precision);
    return fixNegativeZero(a * precision);
}
 
char * efiTrim(char *param) {
    while (param[0] == ' ') {
        param++; // that would skip leading spaces
    }
    int len = std::strlen(param);
    while (len > 0 && param[len - 1] == ' ') {
        param[len - 1] = 0;
        len--;
    }
    return param;
}
 
static char *ltoa_internal(char *p, uint32_t num, unsigned radix) {
    constexpr int bufferLength = 10;
 
    char buffer[bufferLength];
 
    size_t idx = bufferLength - 1;
 
    // First, we write from right-to-left so that we don't have to compute
    // log(num)/log(radix)
    do
    {
        auto digit = num % radix;
 
        // Digits 0-9 -> '0'-'9'
        // Digits 10-15 -> 'a'-'f'
        char c = digit < 10
            ? digit + '0'
            : digit + 'a' - 10;
 
        // Write this digit in to the buffer
        buffer[idx] = c;
        idx--;
    } while ((num /= radix) != 0);
 
    idx++;
 
    // Now, we copy characters in to place in the final buffer
    while (idx < bufferLength)
    {
        *p++ = buffer[idx++];
    }
 
    return p;
}
 
/**
 * @return pointer at the end zero symbol after the digits
 */
static char* itoa_signed(char *p, int num, unsigned radix) {
    if (num < 0) {
        *p++ = '-';
        char *end = ltoa_internal(p, -num, radix);
        *end = 0;
        return end;
    }
    char *end = ltoa_internal(p, num, radix);
    *end = 0;
    return end;
}
 
/**
 * Integer to string
 *
 * @return pointer at the end zero symbol after the digits
 */
char* itoa10(char *p, int num) {
    return itoa_signed(p, num, 10);
}
 
int efiPow10(int param) {
    switch (param) {
    case 0:
        return 1;
    case 1:
        return 10;
    case 2:
        return 100;
    case 3:
        return 1000;
    case 4:
        return 10000;
    case 5:
        return 100000;
    case 6:
        return 1000000;
    case 7:
        return 10000000;
    case 8:
        return 100000000;
    }
    return 10 * efiPow10(10 - 1);
}
 
int djb2lowerCase(const char *str) {
    unsigned long hash = 5381;
    int c;
 
    while ( (c = *str++) ) {
        c = std::tolower(c);
        hash = ((hash << 5) + hash) + c; /* hash * 33 + c */
    }
 
    return hash;
}
 
/**
 * @brief This function knows how to print a histogram_s summary
 */
void printHistogram(Logging *logging, histogram_s *histogram) {
#if EFI_HISTOGRAMS && ! EFI_UNIT_TEST
    int report[5];
    int len = hsReport(histogram, report);
 
    logging->reset();
    logging.append(PROTOCOL_MSG LOG_DELIMITER);
    logging.appendPrintf("histogram %s *", histogram->name);
    for (int i = 0; i < len; i++)
    logging.appendPrintf("%d ", report[i]);
    logging.appendPrintf("*");
    logging.append(LOG_DELIMITER);
    scheduleLogging(logging);
#else
    UNUSED(logging);
    UNUSED(histogram);
 
#endif /* EFI_HISTOGRAMS */
}
 
float limitRateOfChange(float newValue, float oldValue, float incrLimitPerSec, float decrLimitPerSec, float secsPassed) {
    if (newValue >= oldValue)
        return (incrLimitPerSec <= 0.0f) ? newValue : oldValue + std::min(newValue - oldValue, incrLimitPerSec * secsPassed);
    return (decrLimitPerSec <= 0.0f) ? newValue : oldValue - std::min(oldValue - newValue, decrLimitPerSec * secsPassed);
}
 
bool isPhaseInRange(float test, float current, float next) {
    bool afterCurrent = test >= current;
    bool beforeNext = test < next;
 
    if (next > current) {
        // we're not near the end of the cycle, comparison is simple
        // 0            |------------------------|       720
        //            next                    current
        return afterCurrent && beforeNext;
    } else {
        // we're near the end of the cycle so we have to check the wraparound
        // 0 -----------|                        |------ 720
        //            next                    current
        // Check whether test is after current (ie, between current tooth and end of cycle)
        // or if test if before next (ie, between start of cycle and next tooth)
        return afterCurrent || beforeNext;
    }
}
 
static int getBitRangeCommon(const uint8_t data[], int bitIndex, int bitWidth, int secondByteOffset) {
    int byteIndex = bitIndex >> 3;
    int shift = bitIndex - byteIndex * 8;
    int value = data[byteIndex];
    if (shift + bitWidth > 8) {
        value = value + data[secondByteOffset + byteIndex] * 256;
    }
    int mask = (1 << bitWidth) - 1;
    return (value >> shift) & mask;
}
 
// see also getBitRange in lua_lib.h
int getBitRangeLsb(const uint8_t data[], int bitIndex, int bitWidth) {
  return getBitRangeCommon(data, bitIndex, bitWidth, 1);
}
 
// see also getBitRangeMsb in lua_lib.h
int getBitRangeMsb(const uint8_t data[], int bitIndex, int bitWidth) {
  return getBitRangeCommon(data, bitIndex, bitWidth, -1);
}
 
void setBitRangeMsb(uint8_t data[], const int totalBitIndex, const int bitWidth, const int value) {
    int leftBitWidh = bitWidth;
    const int byteIndex = totalBitIndex >> 3;
    const int bitInByteIndex = totalBitIndex - byteIndex * 8;
    if (bitInByteIndex + leftBitWidh > 8) {
        const int bitsToHandleNow = 8 - bitInByteIndex;
        setBitRangeMsb(data, (byteIndex - 1) * 8, leftBitWidh - bitsToHandleNow, value >> bitsToHandleNow);
        leftBitWidh = bitsToHandleNow;
    }
    const int mask = (1 << leftBitWidh) - 1;
    data[byteIndex] = data[byteIndex] & (~(mask << bitInByteIndex));
    const int maskedValue = value & mask;
    const int shiftedValue = maskedValue << bitInByteIndex;
    data[byteIndex] = data[byteIndex] | shiftedValue;
}
 
int motorolaMagicFromDbc(int b, int length) {
    // https://github.com/ebroecker/canmatrix/wiki/signal-Byteorder
    // convert from lsb0 bit numbering to msb0 bit numbering (or msb0 to lsb0)
    b = b - (b % 8) + 7 - (b % 8);
    // convert from lsbit of signal data to msbit of signal data, when bit numbering is msb0
    b = b + length - 1;
    // convert from msbit of signal data to lsbit of signal data, when bit numbering is msb0
    b = b - (b % 8) + 7 - (b % 8);
    return b;
}
 
int getBitRangeMoto(const uint8_t data[], int bitIndex, int bitWidth) {
    const int b = motorolaMagicFromDbc(bitIndex, bitWidth);
    return getBitRangeMsb(data, b, bitWidth);
}
 
void setBitRangeMoto(uint8_t data[], const int totalBitIndex, const int bitWidth, const int value) {
    const int b = motorolaMagicFromDbc(totalBitIndex, bitWidth);
    return setBitRangeMsb(data, b, bitWidth, value);
}