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