150 lines
4.4 KiB
C++
150 lines
4.4 KiB
C++
#ifndef CRYPTOPP_ZINFLATE_H
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#define CRYPTOPP_ZINFLATE_H
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#include "filters.h"
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#include <vector>
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NAMESPACE_BEGIN(CryptoPP)
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//! _
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class LowFirstBitReader
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{
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public:
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LowFirstBitReader(BufferedTransformation &store)
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: m_store(store), m_buffer(0), m_bitsBuffered(0) {}
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// unsigned long BitsLeft() const {return m_store.MaxRetrievable() * 8 + m_bitsBuffered;}
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unsigned int BitsBuffered() const {return m_bitsBuffered;}
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unsigned long PeekBuffer() const {return m_buffer;}
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bool FillBuffer(unsigned int length);
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unsigned long PeekBits(unsigned int length);
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void SkipBits(unsigned int length);
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unsigned long GetBits(unsigned int length);
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private:
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BufferedTransformation &m_store;
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unsigned long m_buffer;
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unsigned int m_bitsBuffered;
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};
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struct CodeLessThan;
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//! Huffman Decoder
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class HuffmanDecoder
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{
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public:
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typedef unsigned int code_t;
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typedef unsigned int value_t;
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enum {MAX_CODE_BITS = sizeof(code_t)*8};
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class Err : public Exception {public: Err(const std::string &what) : Exception(INVALID_DATA_FORMAT, "HuffmanDecoder: " + what) {}};
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HuffmanDecoder() {}
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HuffmanDecoder(const unsigned int *codeBitLengths, unsigned int nCodes) {Initialize(codeBitLengths, nCodes);}
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void Initialize(const unsigned int *codeBitLengths, unsigned int nCodes);
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unsigned int Decode(code_t code, /* out */ value_t &value) const;
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bool Decode(LowFirstBitReader &reader, value_t &value) const;
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private:
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friend struct CodeLessThan;
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struct CodeInfo
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{
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CodeInfo(code_t code=0, unsigned int len=0, value_t value=0) : code(code), len(len), value(value) {}
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inline bool operator<(const CodeInfo &rhs) const {return code < rhs.code;}
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code_t code;
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unsigned int len;
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value_t value;
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};
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struct LookupEntry
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{
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unsigned int type;
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union
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{
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value_t value;
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const CodeInfo *begin;
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};
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union
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{
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unsigned int len;
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const CodeInfo *end;
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};
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};
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static code_t NormalizeCode(code_t code, unsigned int codeBits);
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void FillCacheEntry(LookupEntry &entry, code_t normalizedCode) const;
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unsigned int m_maxCodeBits, m_cacheBits, m_cacheMask, m_normalizedCacheMask;
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std::vector<CodeInfo, AllocatorWithCleanup<CodeInfo> > m_codeToValue;
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mutable std::vector<LookupEntry, AllocatorWithCleanup<LookupEntry> > m_cache;
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};
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//! DEFLATE (RFC 1951) decompressor
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class Inflator : public AutoSignaling<Filter>
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{
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public:
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class Err : public Exception
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{
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public:
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Err(ErrorType e, const std::string &s)
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: Exception(e, s) {}
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};
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class UnexpectedEndErr : public Err {public: UnexpectedEndErr() : Err(INVALID_DATA_FORMAT, "Inflator: unexpected end of compressed block") {}};
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class BadBlockErr : public Err {public: BadBlockErr() : Err(INVALID_DATA_FORMAT, "Inflator: error in compressed block") {}};
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/*! \param repeat decompress multiple compressed streams in series
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\param autoSignalPropagation 0 to turn off MessageEnd signal
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*/
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Inflator(BufferedTransformation *attachment = NULL, bool repeat = false, int autoSignalPropagation = -1);
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void IsolatedInitialize(const NameValuePairs ¶meters);
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size_t Put2(const byte *inString, size_t length, int messageEnd, bool blocking);
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bool IsolatedFlush(bool hardFlush, bool blocking);
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virtual unsigned int GetLog2WindowSize() const {return 15;}
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protected:
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ByteQueue m_inQueue;
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private:
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virtual unsigned int MaxPrestreamHeaderSize() const {return 0;}
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virtual void ProcessPrestreamHeader() {}
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virtual void ProcessDecompressedData(const byte *string, size_t length)
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{AttachedTransformation()->Put(string, length);}
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virtual unsigned int MaxPoststreamTailSize() const {return 0;}
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virtual void ProcessPoststreamTail() {}
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void ProcessInput(bool flush);
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void DecodeHeader();
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bool DecodeBody();
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void FlushOutput();
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void OutputByte(byte b);
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void OutputString(const byte *string, size_t length);
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void OutputPast(unsigned int length, unsigned int distance);
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static const HuffmanDecoder *FixedLiteralDecoder();
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static const HuffmanDecoder *FixedDistanceDecoder();
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const HuffmanDecoder& GetLiteralDecoder() const;
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const HuffmanDecoder& GetDistanceDecoder() const;
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enum State {PRE_STREAM, WAIT_HEADER, DECODING_BODY, POST_STREAM, AFTER_END};
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State m_state;
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bool m_repeat, m_eof, m_wrappedAround;
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byte m_blockType;
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word16 m_storedLen;
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enum NextDecode {LITERAL, LENGTH_BITS, DISTANCE, DISTANCE_BITS};
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NextDecode m_nextDecode;
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unsigned int m_literal, m_distance; // for LENGTH_BITS or DISTANCE_BITS
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HuffmanDecoder m_dynamicLiteralDecoder, m_dynamicDistanceDecoder;
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LowFirstBitReader m_reader;
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SecByteBlock m_window;
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size_t m_current, m_lastFlush;
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};
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NAMESPACE_END
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#endif
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