FORCE_INLINE XXH_errorcode XXH64_update_endian()

in lz4/xxhash.c [741:828]

• 79 lines of code
• 7 McCabe index (conditional complexity)

FORCE_INLINE XXH_errorcode XXH64_update_endian (XXH64_state_t* state_in, const void* input, size_t len, XXH_endianess endian)
{
    XXH_istate64_t * state = (XXH_istate64_t *) state_in;
    const BYTE* p = (const BYTE*)input;
    const BYTE* const bEnd = p + len;

#ifdef XXH_ACCEPT_NULL_INPUT_POINTER
    if (input==NULL) return XXH_ERROR;
#endif

    state->total_len += len;

    if (state->memsize + len < 32)   /* fill in tmp buffer */
    {
        XXH_memcpy(((BYTE*)state->mem64) + state->memsize, input, len);
        state->memsize += (U32)len;
        return XXH_OK;
    }

    if (state->memsize)   /* some data left from previous update */
    {
        XXH_memcpy(((BYTE*)state->mem64) + state->memsize, input, 32-state->memsize);
        {
            const U64* p64 = state->mem64;
            state->v1 += XXH_readLE64(p64, endian) * PRIME64_2;
            state->v1 = XXH_rotl64(state->v1, 31);
            state->v1 *= PRIME64_1;
            p64++;
            state->v2 += XXH_readLE64(p64, endian) * PRIME64_2;
            state->v2 = XXH_rotl64(state->v2, 31);
            state->v2 *= PRIME64_1;
            p64++;
            state->v3 += XXH_readLE64(p64, endian) * PRIME64_2;
            state->v3 = XXH_rotl64(state->v3, 31);
            state->v3 *= PRIME64_1;
            p64++;
            state->v4 += XXH_readLE64(p64, endian) * PRIME64_2;
            state->v4 = XXH_rotl64(state->v4, 31);
            state->v4 *= PRIME64_1;
            p64++;
        }
        p += 32-state->memsize;
        state->memsize = 0;
    }

    if (p+32 <= bEnd)
    {
        const BYTE* const limit = bEnd - 32;
        U64 v1 = state->v1;
        U64 v2 = state->v2;
        U64 v3 = state->v3;
        U64 v4 = state->v4;

        do
        {
            v1 += XXH_readLE64(p, endian) * PRIME64_2;
            v1 = XXH_rotl64(v1, 31);
            v1 *= PRIME64_1;
            p+=8;
            v2 += XXH_readLE64(p, endian) * PRIME64_2;
            v2 = XXH_rotl64(v2, 31);
            v2 *= PRIME64_1;
            p+=8;
            v3 += XXH_readLE64(p, endian) * PRIME64_2;
            v3 = XXH_rotl64(v3, 31);
            v3 *= PRIME64_1;
            p+=8;
            v4 += XXH_readLE64(p, endian) * PRIME64_2;
            v4 = XXH_rotl64(v4, 31);
            v4 *= PRIME64_1;
            p+=8;
        }
        while (p<=limit);

        state->v1 = v1;
        state->v2 = v2;
        state->v3 = v3;
        state->v4 = v4;
    }

    if (p < bEnd)
    {
        XXH_memcpy(state->mem64, p, bEnd-p);
        state->memsize = (int)(bEnd-p);
    }

    return XXH_OK;
}