70 lines
1.5 KiB
C++
70 lines
1.5 KiB
C++
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#include <bolt/Compression.hpp>
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#include "bolt/Errors.hpp"
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namespace lightningbolt {
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ErrorOr<std::vector<u8>> BoltDecompress(u8* input, usize decompressedSize) {
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u8* inptr = input;
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std::vector<u8> res;
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res.resize(decompressedSize);
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u8* pOut = res.data();
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u8* pEnd = res.data() + decompressedSize;
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i32 iVar3 = 0;
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i32 iVar6 = 0;
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u32 uVar5 = 0;
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u8* pbVar4 = nullptr; // outrun
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bool bVar1;
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while(pOut < pEnd) {
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auto uVar7 = *inptr++;
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if(uVar7 < 128) { // lookback/run?
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iVar3 = iVar3 + uVar5 * 8 + ((int)(uVar7 & 0x70) >> 4);
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pbVar4 = pOut + -(iVar6 * 0x10 + (uVar7 & 0xf) + 1);
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iVar6 = iVar3 + 1;
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if(iVar3 != -2) {
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do {
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*pOut = *pbVar4;
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pbVar4 = pbVar4 + 1;
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bVar1 = iVar6 != 0;
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pOut = pOut + 1;
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iVar6 = iVar6 + -1;
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} while(bVar1);
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}
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iVar6 = 0;
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iVar3 = 0;
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uVar5 = 0;
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} else if(uVar7 < 144) { // literal copy from stream
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iVar3 = uVar5 * 0x10 + (uVar7 & 0xf) + 1;
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while(iVar3 != 0) {
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iVar3 = iVar3 + -1;
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*pOut = *inptr++;
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pOut = pOut + 1;
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}
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iVar3 = 0;
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uVar5 = 0;
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} else if(uVar7 < 160) {
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uVar5 = uVar7 & 3;
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iVar3 = iVar3 + 1;
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iVar6 = (int)(uVar7 & 0xc) >> 2;
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} else if(uVar7 < 192) {
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uVar5 = uVar5 * 0x20 + (uVar7 & 0x1f);
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iVar3 = iVar3 + 1;
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} else {
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iVar3 = iVar3 + 1;
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iVar6 = iVar6 * 0x40 + (uVar7 & 0x3f);
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}
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}
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if(pOut != pEnd)
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return std::make_error_code(BoltErrc::DecompressionError);
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return res;
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}
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} // namespace lightningbolt
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