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#ifndef CRYPTOPP_ZDEFLATE_H
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#define CRYPTOPP_ZDEFLATE_H
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#include "filters.h"
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#include "misc.h"
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00007 NAMESPACE_BEGIN(CryptoPP)
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00009
00010 class
LowFirstBitWriter : public
Filter
00011 {
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public:
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LowFirstBitWriter(
BufferedTransformation *attachment);
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void PutBits(
unsigned long value,
unsigned int length);
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void FlushBitBuffer();
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void ClearBitBuffer();
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00018
void StartCounting();
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unsigned long FinishCounting();
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00021
protected:
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bool m_counting;
00023
unsigned long m_bitCount;
00024
unsigned long m_buffer;
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unsigned int m_bitsBuffered, m_bytesBuffered;
00026 FixedSizeSecBlock<byte, 256> m_outputBuffer;
00027 };
00028
00029
00030 class HuffmanEncoder
00031 {
00032
public:
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typedef unsigned int code_t;
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typedef unsigned int value_t;
00035
00036
HuffmanEncoder() {}
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HuffmanEncoder(
const unsigned int *codeBits,
unsigned int nCodes);
00038
void Initialize(
const unsigned int *codeBits,
unsigned int nCodes);
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00040
static void GenerateCodeLengths(
unsigned int *codeBits,
unsigned int maxCodeBits,
const unsigned int *codeCounts,
unsigned int nCodes);
00041
00042
void Encode(
LowFirstBitWriter &writer, value_t value)
const;
00043
00044
struct Code
00045 {
00046
unsigned int code;
00047
unsigned int len;
00048 };
00049
00050
SecBlock<Code> m_valueToCode;
00051 };
00052
00053
00054
00055 class Deflator :
public LowFirstBitWriter
00056 {
00057
public:
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enum {MIN_DEFLATE_LEVEL = 0, DEFAULT_DEFLATE_LEVEL = 6, MAX_DEFLATE_LEVEL = 9};
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enum {MIN_LOG2_WINDOW_SIZE = 9, DEFAULT_LOG2_WINDOW_SIZE = 15, MAX_LOG2_WINDOW_SIZE = 15};
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Deflator(
BufferedTransformation *attachment=NULL,
int deflateLevel=DEFAULT_DEFLATE_LEVEL,
int log2WindowSize=DEFAULT_LOG2_WINDOW_SIZE);
00061
00062
Deflator(
const NameValuePairs ¶meters,
BufferedTransformation *attachment=NULL);
00063
00064
00065
void SetDeflateLevel(
int deflateLevel);
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int GetDeflateLevel()
const {
return m_deflateLevel;}
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int GetLog2WindowSize()
const {
return m_log2WindowSize;}
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00069
void IsolatedInitialize(
const NameValuePairs ¶meters);
00070
unsigned int Put2(
const byte *inString,
unsigned int length,
int messageEnd,
bool blocking);
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bool IsolatedFlush(
bool hardFlush,
bool blocking);
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00073
private:
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virtual void WritePrestreamHeader() {}
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virtual void ProcessUncompressedData(
const byte *string,
unsigned int length) {}
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virtual void WritePoststreamTail() {}
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00078
enum {STORED = 0, STATIC = 1, DYNAMIC = 2};
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enum {MIN_MATCH = 3, MAX_MATCH = 258};
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void InitializeStaticEncoders();
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void Reset(
bool forceReset =
false);
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unsigned int FillWindow(
const byte *str,
unsigned int length);
00084
unsigned int ComputeHash(
const byte *str)
const;
00085
unsigned int LongestMatch(
unsigned int &bestMatch)
const;
00086
void InsertString(
unsigned int start);
00087
void ProcessBuffer();
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00089
void LiteralByte(byte b);
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void MatchFound(
unsigned int distance,
unsigned int length);
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void EncodeBlock(
bool eof,
unsigned int blockType);
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void EndBlock(
bool eof);
00093
00094
struct EncodedMatch
00095 {
00096
unsigned literalCode : 9;
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unsigned literalExtra : 5;
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unsigned distanceCode : 5;
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unsigned distanceExtra : 13;
00100 };
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int m_deflateLevel, m_log2WindowSize;
00103
unsigned int DSIZE, DMASK, HSIZE, HMASK, GOOD_MATCH, MAX_LAZYLENGTH, MAX_CHAIN_LENGTH;
00104
bool m_headerWritten, m_matchAvailable;
00105
unsigned int m_dictionaryEnd, m_stringStart, m_lookahead, m_minLookahead, m_previousMatch, m_previousLength;
00106
HuffmanEncoder m_staticLiteralEncoder, m_staticDistanceEncoder, m_dynamicLiteralEncoder, m_dynamicDistanceEncoder;
00107
SecByteBlock m_byteBuffer;
00108
SecBlock<word16> m_head, m_prev;
00109 FixedSizeSecBlock<unsigned int, 286> m_literalCounts;
00110 FixedSizeSecBlock<unsigned int, 30> m_distanceCounts;
00111
SecBlock<EncodedMatch> m_matchBuffer;
00112
unsigned int m_matchBufferEnd, m_blockStart, m_blockLength;
00113 };
00114
00115 NAMESPACE_END
00116
00117
#endif