////  DoubleHashKey.cpp//  libraries/shared/src////  Created by Andrew Meadows 2014.11.02//  Copyright 2014 High Fidelity, Inc.////  Distributed under the Apache License, Version 2.0.//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html// #include "DoubleHashKey.h" const uint32_t NUM_PRIMES = 64;const uint32_t PRIMES[] = {     4194301U, 4194287U, 4194277U, 4194271U, 4194247U, 4194217U, 4194199U, 4194191U,    4194187U, 4194181U, 4194173U, 4194167U, 4194143U, 4194137U, 4194131U, 4194107U,    4194103U, 4194023U, 4194011U, 4194007U, 4193977U, 4193971U, 4193963U, 4193957U,    4193939U, 4193929U, 4193909U, 4193869U, 4193807U, 4193803U, 4193801U, 4193789U,    4193759U, 4193753U, 4193743U, 4193701U, 4193663U, 4193633U, 4193573U, 4193569U,    4193551U, 4193549U, 4193531U, 4193513U, 4193507U, 4193459U, 4193447U, 4193443U,    4193417U, 4193411U, 4193393U, 4193389U, 4193381U, 4193377U, 4193369U, 4193359U,    4193353U, 4193327U, 4193309U, 4193303U, 4193297U, 4193279U, 4193269U, 4193263U}; uint32_t DoubleHashKey::hashFunction(uint32_t value, uint32_t primeIndex) {    uint32_t hash = PRIMES[primeIndex % NUM_PRIMES] * (value + 1U);    hash += ~(hash << 15);    hash ^=  (hash >> 10);    hash +=  (hash << 3);     hash ^=  (hash >> 6);     hash += ~(hash << 11);    return hash ^ (hash >> 16);} uint32_t DoubleHashKey::hashFunction2(uint32_t value) {    uint32_t hash = 0x811c9dc5U;    for (uint32_t i = 0; i < 4; i++ ) {        uint32_t byte = (value << (i * 8)) >> (24 - i * 8);        hash = ( hash ^ byte ) * 0x01000193U;    }   return hash;} void DoubleHashKey::computeHash(uint32_t value, uint32_t primeIndex) {    _hash = DoubleHashKey::hashFunction(value, primeIndex);    _hash2 = DoubleHashKey::hashFunction2(value);}