| /* |
| * Copyright (c) 2022 Arm Limited. All rights reserved. |
| * |
| * SPDX-License-Identifier: Apache-2.0 |
| * |
| * 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 |
| * |
| * 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. |
| */ |
| |
| #include <cstddef> |
| #include <inttypes.h> |
| |
| namespace { |
| |
| class Crc { |
| public: |
| constexpr Crc() : table() { |
| uint32_t poly = 0xedb88320; |
| |
| for (uint32_t i = 0; i < 256; i++) { |
| uint32_t crc = i; |
| |
| for (int j = 0; j < 8; j++) { |
| if (crc & 1) { |
| crc = poly ^ (crc >> 1); |
| } else { |
| crc >>= 1; |
| } |
| } |
| |
| table[i] = crc; |
| } |
| } |
| |
| uint32_t crc32(const void *data, const size_t length, uint32_t init = 0) const { |
| uint32_t crc = init ^ 0xffffffff; |
| |
| const uint8_t *v = static_cast<const uint8_t *>(data); |
| |
| for (size_t i = 0; i < length; i++) { |
| crc = table[(crc ^ v[i]) & 0xff] ^ (crc >> 8); |
| } |
| |
| return crc ^ 0xffffffff; |
| } |
| |
| private: |
| uint32_t table[256]; |
| }; |
| } // namespace |