Oskari Alaranta
7c1b403e05
This allows compressing and decompressing with data using GZip headers and footers
50 lines
884 B
C++
50 lines
884 B
C++
#pragma once
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#include <BAN/ByteSpan.h>
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namespace LibDEFLATE
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{
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inline uint32_t calculate_adler32(BAN::ConstByteSpan data)
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{
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uint32_t s1 = 1;
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uint32_t s2 = 0;
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for (size_t i = 0; i < data.size(); i++)
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{
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s1 = (s1 + data[i]) % 65521;
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s2 = (s2 + s1) % 65521;
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}
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return (s2 << 16) | s1;
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}
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inline uint32_t calculate_crc32(BAN::ConstByteSpan data)
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{
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uint32_t crc32 = 0xFFFFFFFF;
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uint32_t polynomial = 0xEDB88320;
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for (size_t i = 0; i < data.size(); i++) {
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crc32 ^= data[i];
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for (size_t j = 0; j < 8; j++) {
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if (crc32 & 1)
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crc32 = (crc32 >> 1) ^ polynomial;
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else
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crc32 >>= 1;
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}
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}
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return ~crc32;
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}
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inline constexpr uint16_t reverse_bits(uint16_t value, size_t count)
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{
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uint16_t reverse = 0;
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for (uint8_t bit = 0; bit < count; bit++)
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reverse |= ((value >> bit) & 1) << (count - bit - 1);
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return reverse;
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}
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}
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