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/*
* 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
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