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149 lines
4.4 KiB
149 lines
4.4 KiB
#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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