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src/SpookyV2.cpp  view on Meta::CPAN

    uint64* hash1,
    uint64* hash2)
{
    if (length < sc_bufSize) {
        Short(message, length, hash1, hash2);
        return;
    }

    uint64 h0, h1, h2, h3, h4, h5, h6, h7, h8, h9, h10, h11;
    uint64 buf[sc_numVars];
    uint64* end;
    union {
        const uint8* p8;
        uint64* p64;
        size_t i;
    } u;
    size_t remainder;

    h0 = h3 = h6 = h9 = *hash1;
    h1 = h4 = h7 = h10 = *hash2;
    h2 = h5 = h8 = h11 = sc_const;

    u.p8 = (const uint8*)message;
    end = u.p64 + (length / sc_blockSize) * sc_numVars;

    // handle all whole sc_blockSize blocks of bytes
    if (ALLOW_UNALIGNED_READS || ((u.i & 0x7) == 0)) {
        while (u.p64 < end) {
            Mix(u.p64, h0, h1, h2, h3, h4, h5, h6, h7, h8, h9, h10, h11);
            u.p64 += sc_numVars;
        }
    } else {
        while (u.p64 < end) {
            memcpy(buf, u.p64, sc_blockSize);
            Mix(buf, h0, h1, h2, h3, h4, h5, h6, h7, h8, h9, h10, h11);
            u.p64 += sc_numVars;
        }
    }

    // handle the last partial block of sc_blockSize bytes
    remainder = (length - ((const uint8*)end - (const uint8*)message));
    memcpy(buf, end, remainder);
    memset(((uint8*)buf) + remainder, 0, sc_blockSize - remainder);
    ((uint8*)buf)[sc_blockSize - 1] = remainder;

    // do some final mixing
    End(buf, h0, h1, h2, h3, h4, h5, h6, h7, h8, h9, h10, h11);
    *hash1 = h0;
    *hash2 = h1;
}

// init spooky state
void SpookyHash::Init(uint64 seed1, uint64 seed2)
{
    m_length = 0;
    m_remainder = 0;
    m_state[0] = seed1;
    m_state[1] = seed2;
}

// add a message fragment to the state
void SpookyHash::Update(const void* message, size_t length)
{
    uint64 h0, h1, h2, h3, h4, h5, h6, h7, h8, h9, h10, h11;
    size_t newLength = length + m_remainder;
    uint8 remainder;
    union {
        const uint8* p8;
        uint64* p64;
        size_t i;
    } u;
    const uint64* end;

    // Is this message fragment too short?  If it is, stuff it away.
    if (newLength < sc_bufSize) {
        memcpy(&((uint8*)m_data)[m_remainder], message, length);
        m_length = length + m_length;
        m_remainder = (uint8)newLength;
        return;
    }

    // init the variables
    if (m_length < sc_bufSize) {
        h0 = h3 = h6 = h9 = m_state[0];
        h1 = h4 = h7 = h10 = m_state[1];
        h2 = h5 = h8 = h11 = sc_const;
    } else {
        h0 = m_state[0];
        h1 = m_state[1];
        h2 = m_state[2];
        h3 = m_state[3];
        h4 = m_state[4];
        h5 = m_state[5];
        h6 = m_state[6];
        h7 = m_state[7];
        h8 = m_state[8];
        h9 = m_state[9];
        h10 = m_state[10];
        h11 = m_state[11];
    }
    m_length = length + m_length;

    // if we've got anything stuffed away, use it now
    if (m_remainder) {
        uint8 prefix = sc_bufSize - m_remainder;
        memcpy(&(((uint8*)m_data)[m_remainder]), message, prefix);
        u.p64 = m_data;
        Mix(u.p64, h0, h1, h2, h3, h4, h5, h6, h7, h8, h9, h10, h11);
        Mix(&u.p64[sc_numVars], h0, h1, h2, h3, h4, h5, h6, h7, h8, h9, h10, h11);
        u.p8 = ((const uint8*)message) + prefix;
        length -= prefix;
    } else {
        u.p8 = (const uint8*)message;
    }

    // handle all whole blocks of sc_blockSize bytes
    end = u.p64 + (length / sc_blockSize) * sc_numVars;
    remainder = (uint8)(length - ((const uint8*)end - u.p8));
    if (ALLOW_UNALIGNED_READS || (u.i & 0x7) == 0) {
        while (u.p64 < end) {
            Mix(u.p64, h0, h1, h2, h3, h4, h5, h6, h7, h8, h9, h10, h11);
            u.p64 += sc_numVars;
        }
    } else {
        while (u.p64 < end) {
            memcpy(m_data, u.p8, sc_blockSize);
            Mix(m_data, h0, h1, h2, h3, h4, h5, h6, h7, h8, h9, h10, h11);
            u.p64 += sc_numVars;
        }
    }

    // stuff away the last few bytes
    m_remainder = remainder;
    memcpy(m_data, end, remainder);

    // stuff away the variables
    m_state[0] = h0;
    m_state[1] = h1;
    m_state[2] = h2;
    m_state[3] = h3;
    m_state[4] = h4;
    m_state[5] = h5;
    m_state[6] = h6;
    m_state[7] = h7;
    m_state[8] = h8;
    m_state[9] = h9;
    m_state[10] = h10;
    m_state[11] = h11;
}

// report the hash for the concatenation of all message fragments so far
void SpookyHash::Final(uint64* hash1, uint64* hash2)
{
    // init the variables
    if (m_length < sc_bufSize) {
        *hash1 = m_state[0];
        *hash2 = m_state[1];
        Short(m_data, m_length, hash1, hash2);
        return;
    }

    const uint64* data = (const uint64*)m_data;
    uint8 remainder = m_remainder;

    uint64 h0 = m_state[0];
    uint64 h1 = m_state[1];
    uint64 h2 = m_state[2];
    uint64 h3 = m_state[3];
    uint64 h4 = m_state[4];
    uint64 h5 = m_state[5];
    uint64 h6 = m_state[6];
    uint64 h7 = m_state[7];
    uint64 h8 = m_state[8];
    uint64 h9 = m_state[9];
    uint64 h10 = m_state[10];
    uint64 h11 = m_state[11];

    if (remainder >= sc_blockSize) {
        // m_data can contain two blocks; handle any whole first block
        Mix(data, h0, h1, h2, h3, h4, h5, h6, h7, h8, h9, h10, h11);
        data += sc_numVars;
        remainder -= sc_blockSize;
    }

    // mix in the last partial block, and the length mod sc_blockSize
    memset(&((uint8*)data)[remainder], 0, (sc_blockSize - remainder));

    ((uint8*)data)[sc_blockSize - 1] = remainder;

    // do some final mixing
    End(data, h0, h1, h2, h3, h4, h5, h6, h7, h8, h9, h10, h11);

    *hash1 = h0;
    *hash2 = h1;
}