cef12aac6d
files that use a literal table and 8k dictionary, and that the just-added Shrink support works at all. - Replaced the bit-at-a-time Shannon-Fano decoder from GunZip.c64 with the word-at-a-time one from 7-Zip for a slight speedup when working with Imploded files. SVN r1588 (trunk)
47 lines
No EOL
1.4 KiB
C++
47 lines
No EOL
1.4 KiB
C++
#include "files.h"
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#include "doomerrors.h"
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class FZipExploder
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{
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unsigned int Hold, Bits;
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FileReader *In;
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unsigned int InLeft;
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/****************************************************************
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Shannon-Fano tree structures, variables and related routines
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****************************************************************/
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enum { kNumBitsInLongestCode = 16 };
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struct DecoderBase
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{
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unsigned int Limits[kNumBitsInLongestCode + 2]; // Limits[i] = value limit for symbols with length = i
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unsigned char Positions[kNumBitsInLongestCode + 2]; // Positions[i] = index in Symbols[] of first symbol with length = i
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unsigned char Symbols[1];
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bool SetCodeLengths(const unsigned char *codeLengths, const int kNumSymbols);
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};
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template<int kNumSymbols>
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struct Decoder : DecoderBase
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{
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unsigned char RestOfSymbols[kNumSymbols];
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};
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Decoder<256> LiteralDecoder;
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Decoder<64> DistanceDecoder;
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Decoder<64> LengthDecoder;
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int DecodeSFValue(const DecoderBase ¤tTree, const unsigned int kNumSymbols);
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int DecodeSF(unsigned char *table);
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public:
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int Explode(unsigned char *out, unsigned int outsize, FileReader *in, unsigned int insize, int flags);
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};
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class CExplosionError : CRecoverableError
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{
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public:
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CExplosionError(const char *message) : CRecoverableError(message) {}
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};
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int ShrinkLoop(unsigned char *out, unsigned int outsize, FileReader *in, unsigned int insize); |