crcsoftware.h

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#ifndef SEMF_UTILS_PROCESSING_CRCSOFTWARE_H_
#define SEMF_UTILS_PROCESSING_CRCSOFTWARE_H_
 
#include <semf/app/processing/crc.h>
#include <semf/utils/core/debug.h>
#include <algorithm>
#include <cstring>
#include <cstdint>
 
namespace semf
{
template <typename T, T DEFAULT_POLYNOMIAL, T DEFAULT_INITVALUE, T DEFAULT_FINALXOR>
class CrcSoftware : public app::Crc
{
public:
    explicit CrcSoftware(T polynomial = DEFAULT_POLYNOMIAL, T initValue = DEFAULT_INITVALUE, T finalXor = DEFAULT_FINALXOR);
    virtual ~CrcSoftware() = default;
 
    void reset();
    const uint8_t* accumulate(const uint8_t data[], size_t dataSize) override;
    const uint8_t* calculate(const uint8_t data[], size_t dataSize) override;
    bool isEqual(const uint8_t data[]) override;
    size_t bitSize() const override;
    size_t byteSize() const override;
 
private:
    static T invertBitSequence(T value);
    const T m_invertedPolynomial;
    const T m_initValue;
    const T m_finalXor;
    T m_crc;
};
 
template <typename T, T DEFAULT_POLYNOMIAL, T DEFAULT_INITVALUE, T DEFAULT_FINALXOR>
CrcSoftware<T, DEFAULT_POLYNOMIAL, DEFAULT_INITVALUE, DEFAULT_FINALXOR>::CrcSoftware(T polynomial, T initValue, T finalXor)
: m_invertedPolynomial(invertBitSequence(polynomial)),
  m_initValue(initValue),
  m_finalXor(finalXor),
  m_crc(initValue ^ m_finalXor)
{
}
 
template <typename T, T DEFAULT_POLYNOMIAL, T DEFAULT_INITVALUE, T DEFAULT_FINALXOR>
void CrcSoftware<T, DEFAULT_POLYNOMIAL, DEFAULT_INITVALUE, DEFAULT_FINALXOR>::reset()
{
    SEMF_INFO("reset");
    m_crc = m_initValue ^ m_finalXor;
}
 
template <typename T, T DEFAULT_POLYNOMIAL, T DEFAULT_INITVALUE, T DEFAULT_FINALXOR>
const uint8_t* CrcSoftware<T, DEFAULT_POLYNOMIAL, DEFAULT_INITVALUE, DEFAULT_FINALXOR>::accumulate(const uint8_t data[], size_t dataSize)
{
    m_crc ^= m_finalXor;
    for (size_t i = 0; i < dataSize; i++)
    {
        m_crc ^= data[i];
 
        for (int i = 0; i < 8; i++)
        {
            T sum = ~((m_crc & 1) - 1);
            m_crc = (m_crc >> 1) ^ (m_invertedPolynomial & sum);
        }
    }
    m_crc ^= m_finalXor;
    SEMF_INFO("accumulated with data %p and size %u to crc value %u", data, dataSize, m_crc);
    return reinterpret_cast<const uint8_t*>(&m_crc);
}
 
template <typename T, T DEFAULT_POLYNOMIAL, T DEFAULT_INITVALUE, T DEFAULT_FINALXOR>
const uint8_t* CrcSoftware<T, DEFAULT_POLYNOMIAL, DEFAULT_INITVALUE, DEFAULT_FINALXOR>::calculate(const uint8_t data[], size_t dataSize)
{
    m_crc = m_initValue ^ m_finalXor;
    accumulate(data, dataSize);
    SEMF_INFO("calculated with data %p and size %u to crc value %u", data, dataSize, m_crc);
    return reinterpret_cast<const uint8_t*>(&m_crc);
}
 
template <typename T, T DEFAULT_POLYNOMIAL, T DEFAULT_INITVALUE, T DEFAULT_FINALXOR>
bool CrcSoftware<T, DEFAULT_POLYNOMIAL, DEFAULT_INITVALUE, DEFAULT_FINALXOR>::isEqual(const uint8_t data[])
{
    if (data == nullptr)
    {
        SEMF_ERROR("input is nullptr");
        return false;
    }
    bool e = std::memcmp(reinterpret_cast<const uint8_t*>(&m_crc), data, sizeof(T)) == 0;
    SEMF_INFO("crc equal: %d", e);
    return e;
}
 
template <typename T, T DEFAULT_POLYNOMIAL, T DEFAULT_INITVALUE, T DEFAULT_FINALXOR>
size_t CrcSoftware<T, DEFAULT_POLYNOMIAL, DEFAULT_INITVALUE, DEFAULT_FINALXOR>::bitSize() const
{
    return sizeof(T) * 8;
}
 
template <typename T, T DEFAULT_POLYNOMIAL, T DEFAULT_INITVALUE, T DEFAULT_FINALXOR>
size_t CrcSoftware<T, DEFAULT_POLYNOMIAL, DEFAULT_INITVALUE, DEFAULT_FINALXOR>::byteSize() const
{
    size_t ret = bitSize() / 8;
    return (bitSize() % 8 == 0) ? ret : ret + 1;
}
 
template <typename T, T DEFAULT_POLYNOMIAL, T DEFAULT_INITVALUE, T DEFAULT_FINALXOR>
T CrcSoftware<T, DEFAULT_POLYNOMIAL, DEFAULT_INITVALUE, DEFAULT_FINALXOR>::invertBitSequence(T value)
{
    T retVal = 0;
    for (size_t i = 0; i < sizeof(T) * 8; i++)
    {
        retVal |= (((1 << i) & value) ? 1u : 0u) << (sizeof(T) * 8 - 1 - i);
    }
 
    return retVal;
}
 
typedef CrcSoftware<uint32_t, 0x04C11DB7, 0xFFFFFFFF, 0xFFFFFFFF> Crc32Software;
typedef CrcSoftware<uint16_t, 0x1021, 0xFFFF, 0xFFFF> Crc16Software;
typedef CrcSoftware<uint8_t, 0x07, 0xFF, 0xFF> Crc8Sofware;
} /* namespace semf */
#endif /* SEMF_UTILS_PROCESSING_CRCSOFTWARE_H_ */