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/*
* Copyright (C) 2012 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/* Implementation of Jenkins one-at-a-time hash function. These choices are
* optimized for code size and portability, rather than raw speed. But speed
* should still be quite good.
**/
#ifndef ANDROID_JENKINS_HASH_H
#define ANDROID_JENKINS_HASH_H
#include <utils/TypeHelpers.h>
namespace android {
/* The Jenkins hash of a sequence of 32 bit words A, B, C is:
* Whiten(Mix(Mix(Mix(0, A), B), C)) */
inline uint32_t JenkinsHashMix(uint32_t hash, uint32_t data) {
hash += data;
hash += (hash << 10);
hash ^= (hash >> 6);
return hash;
}
hash_t JenkinsHashWhiten(uint32_t hash);
/* Helpful utility functions for hashing data in 32 bit chunks */
uint32_t JenkinsHashMixBytes(uint32_t hash, const uint8_t* bytes, size_t size);
uint32_t JenkinsHashMixShorts(uint32_t hash, const uint16_t* shorts, size_t size);
}
#endif // ANDROID_JENKINS_HASH_H
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