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https://github.com/aaru-dps/Aaru.Compression.Native.git
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56 lines
1.6 KiB
C
56 lines
1.6 KiB
C
/*
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* This file is part of the Aaru Data Preservation Suite.
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* Copyright (c) 2019-2025 Natalia Portillo.
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*
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* This library is free software; you can redistribute it and/or modify
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* it under the terms of the GNU Lesser General Public License as
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* published by the Free Software Foundation; either version 2.1 of the
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* License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with this library; if not, see <http://www.gnu.org/licenses/>.
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*/
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#ifdef __cplusplus
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extern "C"
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{
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#endif
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#include <stdint.h>
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#define CRC32_ISO_POLY 0xEDB88320
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#define CRC32_ISO_SEED 0xFFFFFFFF
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uint32_t crc32_data(const uint8_t *data, uint32_t len)
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{
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uint32_t localHashInt = CRC32_ISO_SEED;
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uint32_t localTable[256];
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int i, j;
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for(i = 0; i < 256; i++)
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{
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uint32_t entry = (uint32_t)i;
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for(j = 0; j < 8; j++)
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if((entry & 1) == 1)
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entry = (entry >> 1) ^ CRC32_ISO_POLY;
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else
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entry >>= 1;
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localTable[i] = entry;
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}
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for(i = 0; i < len; i++) localHashInt = (localHashInt >> 8) ^ localTable[data[i] ^ (localHashInt & 0xff)];
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localHashInt ^= CRC32_ISO_SEED;
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return localHashInt;
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}
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#ifdef __cplusplus
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}
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#endif |