/* * 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)) */ #ifdef __clang__ __attribute__((no_sanitize("integer"))) #endif 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