1 /* 2 * Copyright (c) 2022 Huawei Device Co., Ltd. 3 * Licensed under the Apache License, Version 2.0 (the "License"); 4 * you may not use this file except in compliance with the License. 5 * You may obtain a copy of the License at 6 * 7 * http://www.apache.org/licenses/LICENSE-2.0 8 * 9 * Unless required by applicable law or agreed to in writing, software 10 * distributed under the License is distributed on an "AS IS" BASIS, 11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12 * See the License for the specific language governing permissions and 13 * limitations under the License. 14 */ 15 16 #ifndef COMMON_COMPONENTS_PLATFORM_STRING_HASH_H 17 #define COMMON_COMPONENTS_PLATFORM_STRING_HASH_H 18 19 #include <cstddef> 20 #include <cstdint> 21 22 namespace common { 23 class StringHash { 24 public: 25 static constexpr size_t BLOCK_SIZE = 4; 26 static constexpr size_t SIMD_U8_LOOP_SIZE = 8; 27 static constexpr size_t MIN_SIZE_FOR_UNROLLING = 32; 28 29 static constexpr uint32_t HASH_SHIFT = 5; 30 static constexpr uint32_t HASH_MULTIPLY = 31; 31 static constexpr uint32_t BLOCK_MULTIPLY = 31 * 31 * 31 * 31; 32 33 static constexpr uint32_t MULTIPLIER[BLOCK_SIZE] = { 31 * 31 * 31, 31 * 31, 31, 1 }; 34 35 static constexpr size_t SIZE_1 = 1; 36 static constexpr size_t SIZE_2 = 2; 37 static constexpr size_t SIZE_3 = 3; 38 }; 39 } // namespace common 40 #endif // COMMON_COMPONENTS_PLATFORM_STRING_HASH_H 41