From 48809d4e85c125814425c621d8d0d89f95405924 Mon Sep 17 00:00:00 2001 From: Jeffrey Walton Date: Thu, 5 Nov 2015 01:59:46 -0500 Subject: CRYPTOPP 5.6.3 RC6 checkin --- zdeflate.cpp | 1613 +++++++++++++++++++++++++++++----------------------------- 1 file changed, 806 insertions(+), 807 deletions(-) (limited to 'zdeflate.cpp') diff --git a/zdeflate.cpp b/zdeflate.cpp index 9b0aea03..a9e0405a 100644 --- a/zdeflate.cpp +++ b/zdeflate.cpp @@ -1,807 +1,806 @@ -// zdeflate.cpp - written and placed in the public domain by Wei Dai - -// Many of the algorithms and tables used here came from the deflate implementation -// by Jean-loup Gailly, which was included in Crypto++ 4.0 and earlier. I completely -// rewrote it in order to fix a bug that I could not figure out. This code -// is less clever, but hopefully more understandable and maintainable. - -#include "pch.h" -#include "zdeflate.h" -#include -#include // ptrdiff_t - -#if _MSC_VER >= 1600 -// for make_unchecked_array_iterator -#include -#endif - -NAMESPACE_BEGIN(CryptoPP) - -using namespace std; - -LowFirstBitWriter::LowFirstBitWriter(BufferedTransformation *attachment) - : Filter(attachment), m_counting(false), m_buffer(0), m_bitsBuffered(0), m_bytesBuffered(0) -{ -} - -void LowFirstBitWriter::StartCounting() -{ - CRYPTOPP_ASSERT(!m_counting); - m_counting = true; - m_bitCount = 0; -} - -unsigned long LowFirstBitWriter::FinishCounting() -{ - CRYPTOPP_ASSERT(m_counting); - m_counting = false; - return m_bitCount; -} - -void LowFirstBitWriter::PutBits(unsigned long value, unsigned int length) -{ - if (m_counting) - m_bitCount += length; - else - { - m_buffer |= value << m_bitsBuffered; - m_bitsBuffered += length; - CRYPTOPP_ASSERT(m_bitsBuffered <= sizeof(unsigned long)*8); - while (m_bitsBuffered >= 8) - { - m_outputBuffer[m_bytesBuffered++] = (byte)m_buffer; - if (m_bytesBuffered == m_outputBuffer.size()) - { - AttachedTransformation()->PutModifiable(m_outputBuffer, m_bytesBuffered); - m_bytesBuffered = 0; - } - m_buffer >>= 8; - m_bitsBuffered -= 8; - } - } -} - -void LowFirstBitWriter::FlushBitBuffer() -{ - if (m_counting) - m_bitCount += 8*(m_bitsBuffered > 0); - else - { - if (m_bytesBuffered > 0) - { - AttachedTransformation()->PutModifiable(m_outputBuffer, m_bytesBuffered); - m_bytesBuffered = 0; - } - if (m_bitsBuffered > 0) - { - AttachedTransformation()->Put((byte)m_buffer); - m_buffer = 0; - m_bitsBuffered = 0; - } - } -} - -void LowFirstBitWriter::ClearBitBuffer() -{ - m_buffer = 0; - m_bytesBuffered = 0; - m_bitsBuffered = 0; -} - -HuffmanEncoder::HuffmanEncoder(const unsigned int *codeBits, unsigned int nCodes) -{ - Initialize(codeBits, nCodes); -} - -struct HuffmanNode -{ - size_t symbol; - union {size_t parent; unsigned depth, freq;}; -}; - -struct FreqLessThan -{ - inline bool operator()(unsigned int lhs, const HuffmanNode &rhs) {return lhs < rhs.freq;} - inline bool operator()(const HuffmanNode &lhs, const HuffmanNode &rhs) const {return lhs.freq < rhs.freq;} - // needed for MSVC .NET 2005 - inline bool operator()(const HuffmanNode &lhs, unsigned int rhs) {return lhs.freq < rhs;} -}; - -void HuffmanEncoder::GenerateCodeLengths(unsigned int *codeBits, unsigned int maxCodeBits, const unsigned int *codeCounts, size_t nCodes) -{ - CRYPTOPP_ASSERT(nCodes > 0); - CRYPTOPP_ASSERT(nCodes <= ((size_t)1 << maxCodeBits)); - - size_t i; - SecBlockWithHint tree(nCodes); - for (i=0; i= 2) - for (i=tree.size()-2; i>=nCodes; i--) - tree[i].depth = tree[tree[i].parent].depth + 1; - unsigned int sum = 0; - SecBlockWithHint blCount(maxCodeBits+1); - fill(blCount.begin(), blCount.end(), 0); - for (i=treeBegin; i (unsigned int)(1 << maxCodeBits) ? sum - (1 << maxCodeBits) : 0; - - while (overflow--) - { - unsigned int bits = maxCodeBits-1; - while (blCount[bits] == 0) - bits--; - blCount[bits]--; - blCount[bits+1] += 2; - CRYPTOPP_ASSERT(blCount[maxCodeBits] > 0); - blCount[maxCodeBits]--; - } - - for (i=0; i 0); - unsigned int maxCodeBits = *max_element(codeBits, codeBits+nCodes); - if (maxCodeBits == 0) - return; // assume this object won't be used - - SecBlockWithHint blCount(maxCodeBits+1); - fill(blCount.begin(), blCount.end(), 0); - unsigned int i; - for (i=0; i nextCode(maxCodeBits+1); - nextCode[1] = 0; - for (i=2; i<=maxCodeBits; i++) - { - code = (code + blCount[i-1]) << 1; - nextCode[i] = code; - } - CRYPTOPP_ASSERT(maxCodeBits == 1 || code == (1 << maxCodeBits) - blCount[maxCodeBits]); - - m_valueToCode.resize(nCodes); - for (i=0; i> (8*sizeof(code_t)-len); - } -} - -inline void HuffmanEncoder::Encode(LowFirstBitWriter &writer, value_t value) const -{ - CRYPTOPP_ASSERT(m_valueToCode[value].len > 0); - writer.PutBits(m_valueToCode[value].code, m_valueToCode[value].len); -} - -Deflator::Deflator(BufferedTransformation *attachment, int deflateLevel, int log2WindowSize, bool detectUncompressible) - : LowFirstBitWriter(attachment) - , m_deflateLevel(-1) -{ - InitializeStaticEncoders(); - IsolatedInitialize(MakeParameters("DeflateLevel", deflateLevel)("Log2WindowSize", log2WindowSize)("DetectUncompressible", detectUncompressible)); -} - -Deflator::Deflator(const NameValuePairs ¶meters, BufferedTransformation *attachment) - : LowFirstBitWriter(attachment) - , m_deflateLevel(-1) -{ - InitializeStaticEncoders(); - IsolatedInitialize(parameters); -} - -void Deflator::InitializeStaticEncoders() -{ - unsigned int codeLengths[288]; - fill(codeLengths + 0, codeLengths + 144, 8); - fill(codeLengths + 144, codeLengths + 256, 9); - fill(codeLengths + 256, codeLengths + 280, 7); - fill(codeLengths + 280, codeLengths + 288, 8); - m_staticLiteralEncoder.Initialize(codeLengths, 288); - fill(codeLengths + 0, codeLengths + 32, 5); - m_staticDistanceEncoder.Initialize(codeLengths, 32); -} - -void Deflator::IsolatedInitialize(const NameValuePairs ¶meters) -{ - int log2WindowSize = parameters.GetIntValueWithDefault("Log2WindowSize", DEFAULT_LOG2_WINDOW_SIZE); - if (!(MIN_LOG2_WINDOW_SIZE <= log2WindowSize && log2WindowSize <= MAX_LOG2_WINDOW_SIZE)) - throw InvalidArgument("Deflator: " + IntToString(log2WindowSize) + " is an invalid window size"); - - m_log2WindowSize = log2WindowSize; - DSIZE = 1 << m_log2WindowSize; - DMASK = DSIZE - 1; - HSIZE = 1 << m_log2WindowSize; - HMASK = HSIZE - 1; - m_byteBuffer.New(2*DSIZE); - m_head.New(HSIZE); - m_prev.New(DSIZE); - m_matchBuffer.New(DSIZE/2); - Reset(true); - - SetDeflateLevel(parameters.GetIntValueWithDefault("DeflateLevel", DEFAULT_DEFLATE_LEVEL)); - bool detectUncompressible = parameters.GetValueWithDefault("DetectUncompressible", true); - m_compressibleDeflateLevel = detectUncompressible ? m_deflateLevel : 0; -} - -void Deflator::Reset(bool forceReset) -{ - if (forceReset) - ClearBitBuffer(); - else - CRYPTOPP_ASSERT(m_bitsBuffered == 0); - - m_headerWritten = false; - m_matchAvailable = false; - m_dictionaryEnd = 0; - m_stringStart = 0; - m_lookahead = 0; - m_minLookahead = MAX_MATCH; - m_matchBufferEnd = 0; - m_blockStart = 0; - m_blockLength = 0; - - m_detectCount = 1; - m_detectSkip = 0; - - // m_prev will be initialized automaticly in InsertString - fill(m_head.begin(), m_head.end(), word16(0)); - - fill(m_literalCounts.begin(), m_literalCounts.end(), 0); - fill(m_distanceCounts.begin(), m_distanceCounts.end(), 0); -} - -void Deflator::SetDeflateLevel(int deflateLevel) -{ - if (!(MIN_DEFLATE_LEVEL <= deflateLevel && deflateLevel <= MAX_DEFLATE_LEVEL)) - throw InvalidArgument("Deflator: " + IntToString(deflateLevel) + " is an invalid deflate level"); - - if (deflateLevel == m_deflateLevel) - return; - - EndBlock(false); - - static const unsigned int configurationTable[10][4] = { - /* good lazy nice chain */ - /* 0 */ {0, 0, 0, 0}, /* store only */ - /* 1 */ {4, 3, 8, 4}, /* maximum speed, no lazy matches */ - /* 2 */ {4, 3, 16, 8}, - /* 3 */ {4, 3, 32, 32}, - /* 4 */ {4, 4, 16, 16}, /* lazy matches */ - /* 5 */ {8, 16, 32, 32}, - /* 6 */ {8, 16, 128, 128}, - /* 7 */ {8, 32, 128, 256}, - /* 8 */ {32, 128, 258, 1024}, - /* 9 */ {32, 258, 258, 4096}}; /* maximum compression */ - - GOOD_MATCH = configurationTable[deflateLevel][0]; - MAX_LAZYLENGTH = configurationTable[deflateLevel][1]; - MAX_CHAIN_LENGTH = configurationTable[deflateLevel][3]; - - m_deflateLevel = deflateLevel; -} - -unsigned int Deflator::FillWindow(const byte *str, size_t length) -{ - unsigned int maxBlockSize = (unsigned int)STDMIN(2UL*DSIZE, 0xffffUL); - - if (m_stringStart >= maxBlockSize - MAX_MATCH) - { - if (m_blockStart < DSIZE) - EndBlock(false); - - memcpy(m_byteBuffer, m_byteBuffer + DSIZE, DSIZE); - - m_dictionaryEnd = m_dictionaryEnd < DSIZE ? 0 : m_dictionaryEnd-DSIZE; - CRYPTOPP_ASSERT(m_stringStart >= DSIZE); - m_stringStart -= DSIZE; - CRYPTOPP_ASSERT(!m_matchAvailable || m_previousMatch >= DSIZE); - m_previousMatch -= DSIZE; - CRYPTOPP_ASSERT(m_blockStart >= DSIZE); - m_blockStart -= DSIZE; - - unsigned int i; - - for (i=0; i m_stringStart+m_lookahead); - unsigned int accepted = UnsignedMin(maxBlockSize-(m_stringStart+m_lookahead), length); - CRYPTOPP_ASSERT(accepted > 0); - memcpy(m_byteBuffer + m_stringStart + m_lookahead, str, accepted); - m_lookahead += accepted; - return accepted; -} - -inline unsigned int Deflator::ComputeHash(const byte *str) const -{ - CRYPTOPP_ASSERT(str+3 <= m_byteBuffer + m_stringStart + m_lookahead); - return ((str[0] << 10) ^ (str[1] << 5) ^ str[2]) & HMASK; -} - -unsigned int Deflator::LongestMatch(unsigned int &bestMatch) const -{ - CRYPTOPP_ASSERT(m_previousLength < MAX_MATCH); - - bestMatch = 0; - unsigned int bestLength = STDMAX(m_previousLength, (unsigned int)MIN_MATCH-1); - if (m_lookahead <= bestLength) - return 0; - - const byte *scan = m_byteBuffer + m_stringStart, *scanEnd = scan + STDMIN((unsigned int)MAX_MATCH, m_lookahead); - unsigned int limit = m_stringStart > (DSIZE-MAX_MATCH) ? m_stringStart - (DSIZE-MAX_MATCH) : 0; - unsigned int current = m_head[ComputeHash(scan)]; - - unsigned int chainLength = MAX_CHAIN_LENGTH; - if (m_previousLength >= GOOD_MATCH) - chainLength >>= 2; - - while (current > limit && --chainLength > 0) - { - const byte *match = m_byteBuffer + current; - CRYPTOPP_ASSERT(scan + bestLength < m_byteBuffer + m_stringStart + m_lookahead); - if (scan[bestLength-1] == match[bestLength-1] && scan[bestLength] == match[bestLength] && scan[0] == match[0] && scan[1] == match[1]) - { - CRYPTOPP_ASSERT(scan[2] == match[2]); - unsigned int len = (unsigned int)( -#if defined(_STDEXT_BEGIN) && !(defined(_MSC_VER) && (_MSC_VER < 1400 || _MSC_VER >= 1600)) && !defined(_STLPORT_VERSION) - stdext::unchecked_mismatch -#else - std::mismatch -#endif -#if _MSC_VER >= 1600 - (stdext::make_unchecked_array_iterator(scan)+3, stdext::make_unchecked_array_iterator(scanEnd), stdext::make_unchecked_array_iterator(match)+3).first - stdext::make_unchecked_array_iterator(scan)); -#else - (scan+3, scanEnd, match+3).first - scan); -#endif - CRYPTOPP_ASSERT(len != bestLength); - if (len > bestLength) - { - bestLength = len; - bestMatch = current; - - // TODO: should we throw here? - const ptrdiff_t diff = scanEnd - scan; - CRYPTOPP_ASSERT(diff >= 0); - - if (len == static_cast(diff)) - break; - } - } - current = m_prev[current & DMASK]; - } - return (bestMatch > 0) ? bestLength : 0; -} - -inline void Deflator::InsertString(unsigned int start) -{ - unsigned int hash = ComputeHash(m_byteBuffer + start); - m_prev[start & DMASK] = m_head[hash]; - m_head[hash] = static_cast(start); -} - -void Deflator::ProcessBuffer() -{ - if (!m_headerWritten) - { - WritePrestreamHeader(); - m_headerWritten = true; - } - - if (m_deflateLevel == 0) - { - m_stringStart += m_lookahead; - m_lookahead = 0; - m_blockLength = m_stringStart - m_blockStart; - m_matchAvailable = false; - return; - } - - while (m_lookahead > m_minLookahead) - { - while (m_dictionaryEnd < m_stringStart && m_dictionaryEnd+3 <= m_stringStart+m_lookahead) - InsertString(m_dictionaryEnd++); - - if (m_matchAvailable) - { - unsigned int matchPosition, matchLength; - bool usePreviousMatch; - if (m_previousLength >= MAX_LAZYLENGTH) - usePreviousMatch = true; - else - { - matchLength = LongestMatch(matchPosition); - usePreviousMatch = (matchLength == 0); - } - if (usePreviousMatch) - { - MatchFound(m_stringStart-1-m_previousMatch, m_previousLength); - m_stringStart += m_previousLength-1; - m_lookahead -= m_previousLength-1; - m_matchAvailable = false; - } - else - { - m_previousLength = matchLength; - m_previousMatch = matchPosition; - LiteralByte(m_byteBuffer[m_stringStart-1]); - m_stringStart++; - m_lookahead--; - } - } - else - { - m_previousLength = 0; - m_previousLength = LongestMatch(m_previousMatch); - if (m_previousLength) - m_matchAvailable = true; - else - LiteralByte(m_byteBuffer[m_stringStart]); - m_stringStart++; - m_lookahead--; - } - - CRYPTOPP_ASSERT(m_stringStart - (m_blockStart+m_blockLength) == (unsigned int)m_matchAvailable); - } - - if (m_minLookahead == 0 && m_matchAvailable) - { - LiteralByte(m_byteBuffer[m_stringStart-1]); - m_matchAvailable = false; - } -} - -size_t Deflator::Put2(const byte *str, size_t length, int messageEnd, bool blocking) -{ - if (!blocking) - throw BlockingInputOnly("Deflator"); - - size_t accepted = 0; - while (accepted < length) - { - unsigned int newAccepted = FillWindow(str+accepted, length-accepted); - ProcessBuffer(); - // call ProcessUncompressedData() after WritePrestreamHeader() - ProcessUncompressedData(str+accepted, newAccepted); - accepted += newAccepted; - } - CRYPTOPP_ASSERT(accepted == length); - - if (messageEnd) - { - m_minLookahead = 0; - ProcessBuffer(); - EndBlock(true); - FlushBitBuffer(); - WritePoststreamTail(); - Reset(); - } - - Output(0, NULL, 0, messageEnd, blocking); - return 0; -} - -bool Deflator::IsolatedFlush(bool hardFlush, bool blocking) -{ - if (!blocking) - throw BlockingInputOnly("Deflator"); - - m_minLookahead = 0; - ProcessBuffer(); - m_minLookahead = MAX_MATCH; - EndBlock(false); - if (hardFlush) - EncodeBlock(false, STORED); - return false; -} - -void Deflator::LiteralByte(byte b) -{ - if (m_matchBufferEnd == m_matchBuffer.size()) - EndBlock(false); - - m_matchBuffer[m_matchBufferEnd++].literalCode = b; - m_literalCounts[b]++; - m_blockLength++; -} - -void Deflator::MatchFound(unsigned int distance, unsigned int length) -{ - if (m_matchBufferEnd == m_matchBuffer.size()) - EndBlock(false); - - static const unsigned int lengthCodes[] = { - 257, 258, 259, 260, 261, 262, 263, 264, 265, 265, 266, 266, 267, 267, 268, 268, - 269, 269, 269, 269, 270, 270, 270, 270, 271, 271, 271, 271, 272, 272, 272, 272, - 273, 273, 273, 273, 273, 273, 273, 273, 274, 274, 274, 274, 274, 274, 274, 274, - 275, 275, 275, 275, 275, 275, 275, 275, 276, 276, 276, 276, 276, 276, 276, 276, - 277, 277, 277, 277, 277, 277, 277, 277, 277, 277, 277, 277, 277, 277, 277, 277, - 278, 278, 278, 278, 278, 278, 278, 278, 278, 278, 278, 278, 278, 278, 278, 278, - 279, 279, 279, 279, 279, 279, 279, 279, 279, 279, 279, 279, 279, 279, 279, 279, - 280, 280, 280, 280, 280, 280, 280, 280, 280, 280, 280, 280, 280, 280, 280, 280, - 281, 281, 281, 281, 281, 281, 281, 281, 281, 281, 281, 281, 281, 281, 281, 281, - 281, 281, 281, 281, 281, 281, 281, 281, 281, 281, 281, 281, 281, 281, 281, 281, - 282, 282, 282, 282, 282, 282, 282, 282, 282, 282, 282, 282, 282, 282, 282, 282, - 282, 282, 282, 282, 282, 282, 282, 282, 282, 282, 282, 282, 282, 282, 282, 282, - 283, 283, 283, 283, 283, 283, 283, 283, 283, 283, 283, 283, 283, 283, 283, 283, - 283, 283, 283, 283, 283, 283, 283, 283, 283, 283, 283, 283, 283, 283, 283, 283, - 284, 284, 284, 284, 284, 284, 284, 284, 284, 284, 284, 284, 284, 284, 284, 284, - 284, 284, 284, 284, 284, 284, 284, 284, 284, 284, 284, 284, 284, 284, 284, 285}; - static const unsigned int lengthBases[] = {3,4,5,6,7,8,9,10,11,13,15,17,19,23,27,31,35,43,51,59,67,83,99,115,131,163,195,227,258}; - static const unsigned int distanceBases[30] = - {1,2,3,4,5,7,9,13,17,25,33,49,65,97,129,193,257,385,513,769,1025,1537,2049,3073,4097,6145,8193,12289,16385,24577}; - - EncodedMatch &m = m_matchBuffer[m_matchBufferEnd++]; - CRYPTOPP_ASSERT(length >= 3); - unsigned int lengthCode = lengthCodes[length-3]; - m.literalCode = lengthCode; - m.literalExtra = length - lengthBases[lengthCode-257]; - unsigned int distanceCode = (unsigned int)(upper_bound(distanceBases, distanceBases+30, distance) - distanceBases - 1); - m.distanceCode = distanceCode; - m.distanceExtra = distance - distanceBases[distanceCode]; - - m_literalCounts[lengthCode]++; - m_distanceCounts[distanceCode]++; - m_blockLength += length; -} - -inline unsigned int CodeLengthEncode(const unsigned int *begin, - const unsigned int *end, - const unsigned int *& p, - unsigned int &extraBits, - unsigned int &extraBitsLength) -{ - unsigned int v = *p; - if ((end-p) >= 3) - { - const unsigned int *oldp = p; - if (v==0 && p[1]==0 && p[2]==0) - { - for (p=p+3; p!=end && *p==0 && p!=oldp+138; p++) {} - unsigned int repeat = (unsigned int)(p - oldp); - if (repeat <= 10) - { - extraBits = repeat-3; - extraBitsLength = 3; - return 17; - } - else - { - extraBits = repeat-11; - extraBitsLength = 7; - return 18; - } - } - else if (p!=begin && v==p[-1] && v==p[1] && v==p[2]) - { - for (p=p+3; p!=end && *p==v && p!=oldp+6; p++) {} - unsigned int repeat = (unsigned int)(p - oldp); - extraBits = repeat-3; - extraBitsLength = 2; - return 16; - } - } - p++; - extraBits = 0; - extraBitsLength = 0; - return v; -} - -void Deflator::EncodeBlock(bool eof, unsigned int blockType) -{ - PutBits(eof, 1); - PutBits(blockType, 2); - - if (blockType == STORED) - { - CRYPTOPP_ASSERT(m_blockStart + m_blockLength <= m_byteBuffer.size()); - CRYPTOPP_ASSERT(m_blockLength <= 65535); - FlushBitBuffer(); - AttachedTransformation()->PutWord16(static_cast(m_blockLength), LITTLE_ENDIAN_ORDER); - AttachedTransformation()->PutWord16(static_cast(~m_blockLength), LITTLE_ENDIAN_ORDER); - AttachedTransformation()->Put(m_byteBuffer + m_blockStart, m_blockLength); - } - else - { - if (blockType == DYNAMIC) - { -#if defined(_MSC_VER) && !defined(__MWERKS__) && (_MSC_VER <= 1300) - // VC60 and VC7 workaround: built-in reverse_iterator has two template parameters, Dinkumware only has one - typedef reverse_bidirectional_iterator RevIt; -#elif defined(_RWSTD_NO_CLASS_PARTIAL_SPEC) - typedef reverse_iterator RevIt; -#else - typedef reverse_iterator RevIt; -#endif - - FixedSizeSecBlock literalCodeLengths; - FixedSizeSecBlock distanceCodeLengths; - - m_literalCounts[256] = 1; - HuffmanEncoder::GenerateCodeLengths(literalCodeLengths, 15, m_literalCounts, 286); - m_dynamicLiteralEncoder.Initialize(literalCodeLengths, 286); - unsigned int hlit = (unsigned int)(find_if (RevIt(literalCodeLengths.end()), RevIt(literalCodeLengths.begin()+257), bind2nd(not_equal_to(), 0)).base() - (literalCodeLengths.begin()+257)); - - HuffmanEncoder::GenerateCodeLengths(distanceCodeLengths, 15, m_distanceCounts, 30); - m_dynamicDistanceEncoder.Initialize(distanceCodeLengths, 30); - unsigned int hdist = (unsigned int)(find_if (RevIt(distanceCodeLengths.end()), RevIt(distanceCodeLengths.begin()+1), bind2nd(not_equal_to(), 0)).base() - (distanceCodeLengths.begin()+1)); - - SecBlockWithHint combinedLengths(hlit+257+hdist+1); - memcpy(combinedLengths, literalCodeLengths, (hlit+257)*sizeof(unsigned int)); - memcpy(combinedLengths+hlit+257, distanceCodeLengths, (hdist+1)*sizeof(unsigned int)); - - FixedSizeSecBlock codeLengthCodeCounts, codeLengthCodeLengths; - fill(codeLengthCodeCounts.begin(), codeLengthCodeCounts.end(), 0); - const unsigned int *p = combinedLengths.begin(), *begin = combinedLengths.begin(), *end = combinedLengths.end(); - while (p != end) - { - unsigned int code, extraBits, extraBitsLength; - code = CodeLengthEncode(begin, end, p, extraBits, extraBitsLength); - codeLengthCodeCounts[code]++; - } - HuffmanEncoder::GenerateCodeLengths(codeLengthCodeLengths, 7, codeLengthCodeCounts, 19); - HuffmanEncoder codeLengthEncoder(codeLengthCodeLengths, 19); - static const unsigned int border[] = { // Order of the bit length code lengths - 16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15}; - unsigned int hclen = 19; - while (hclen > 4 && codeLengthCodeLengths[border[hclen-1]] == 0) - hclen--; - hclen -= 4; - - PutBits(hlit, 5); - PutBits(hdist, 5); - PutBits(hclen, 4); - - for (unsigned int i=0; i= 257) - { - CRYPTOPP_ASSERT(literalCode <= 285); - PutBits(m_matchBuffer[i].literalExtra, lengthExtraBits[literalCode-257]); - unsigned int distanceCode = m_matchBuffer[i].distanceCode; - distanceEncoder.Encode(*this, distanceCode); - PutBits(m_matchBuffer[i].distanceExtra, distanceExtraBits[distanceCode]); - } - } - literalEncoder.Encode(*this, 256); // end of block - } -} - -void Deflator::EndBlock(bool eof) -{ - if (m_blockLength == 0 && !eof) - return; - - if (m_deflateLevel == 0) - { - EncodeBlock(eof, STORED); - - if (m_compressibleDeflateLevel > 0 && ++m_detectCount == m_detectSkip) - { - m_deflateLevel = m_compressibleDeflateLevel; - m_detectCount = 1; - } - } - else - { - unsigned long storedLen = 8*((unsigned long)m_blockLength+4) + RoundUpToMultipleOf(m_bitsBuffered+3, 8U)-m_bitsBuffered; - - StartCounting(); - EncodeBlock(eof, STATIC); - unsigned long staticLen = FinishCounting(); - - unsigned long dynamicLen; - if (m_blockLength < 128 && m_deflateLevel < 8) - dynamicLen = ULONG_MAX; - else - { - StartCounting(); - EncodeBlock(eof, DYNAMIC); - dynamicLen = FinishCounting(); - } - - if (storedLen <= staticLen && storedLen <= dynamicLen) - { - EncodeBlock(eof, STORED); - - if (m_compressibleDeflateLevel > 0) - { - if (m_detectSkip) - m_deflateLevel = 0; - m_detectSkip = m_detectSkip ? STDMIN(2*m_detectSkip, 128U) : 1; - } - } - else - { - if (staticLen <= dynamicLen) - EncodeBlock(eof, STATIC); - else - EncodeBlock(eof, DYNAMIC); - - if (m_compressibleDeflateLevel > 0) - m_detectSkip = 0; - } - } - - m_matchBufferEnd = 0; - m_blockStart += m_blockLength; - m_blockLength = 0; - fill(m_literalCounts.begin(), m_literalCounts.end(), 0); - fill(m_distanceCounts.begin(), m_distanceCounts.end(), 0); -} - -NAMESPACE_END +// zdeflate.cpp - written and placed in the public domain by Wei Dai + +// Many of the algorithms and tables used here came from the deflate implementation +// by Jean-loup Gailly, which was included in Crypto++ 4.0 and earlier. I completely +// rewrote it in order to fix a bug that I could not figure out. This code +// is less clever, but hopefully more understandable and maintainable. + +#include "pch.h" +#include "zdeflate.h" +#include "misc.h" + +#include + +#if _MSC_VER >= 1600 +// for make_unchecked_array_iterator +#include +#endif + +NAMESPACE_BEGIN(CryptoPP) + +LowFirstBitWriter::LowFirstBitWriter(BufferedTransformation *attachment) + : Filter(attachment), m_counting(false), m_buffer(0), m_bitsBuffered(0), m_bytesBuffered(0) +{ +} + +void LowFirstBitWriter::StartCounting() +{ + assert(!m_counting); + m_counting = true; + m_bitCount = 0; +} + +unsigned long LowFirstBitWriter::FinishCounting() +{ + assert(m_counting); + m_counting = false; + return m_bitCount; +} + +void LowFirstBitWriter::PutBits(unsigned long value, unsigned int length) +{ + if (m_counting) + m_bitCount += length; + else + { + m_buffer |= value << m_bitsBuffered; + m_bitsBuffered += length; + assert(m_bitsBuffered <= sizeof(unsigned long)*8); + while (m_bitsBuffered >= 8) + { + m_outputBuffer[m_bytesBuffered++] = (byte)m_buffer; + if (m_bytesBuffered == m_outputBuffer.size()) + { + AttachedTransformation()->PutModifiable(m_outputBuffer, m_bytesBuffered); + m_bytesBuffered = 0; + } + m_buffer >>= 8; + m_bitsBuffered -= 8; + } + } +} + +void LowFirstBitWriter::FlushBitBuffer() +{ + if (m_counting) + m_bitCount += 8*(m_bitsBuffered > 0); + else + { + if (m_bytesBuffered > 0) + { + AttachedTransformation()->PutModifiable(m_outputBuffer, m_bytesBuffered); + m_bytesBuffered = 0; + } + if (m_bitsBuffered > 0) + { + AttachedTransformation()->Put((byte)m_buffer); + m_buffer = 0; + m_bitsBuffered = 0; + } + } +} + +void LowFirstBitWriter::ClearBitBuffer() +{ + m_buffer = 0; + m_bytesBuffered = 0; + m_bitsBuffered = 0; +} + +HuffmanEncoder::HuffmanEncoder(const unsigned int *codeBits, unsigned int nCodes) +{ + Initialize(codeBits, nCodes); +} + +struct HuffmanNode +{ + size_t symbol; + union {size_t parent; unsigned depth, freq;}; +}; + +struct FreqLessThan +{ + inline bool operator()(unsigned int lhs, const HuffmanNode &rhs) {return lhs < rhs.freq;} + inline bool operator()(const HuffmanNode &lhs, const HuffmanNode &rhs) const {return lhs.freq < rhs.freq;} + // needed for MSVC .NET 2005 + inline bool operator()(const HuffmanNode &lhs, unsigned int rhs) {return lhs.freq < rhs;} +}; + +void HuffmanEncoder::GenerateCodeLengths(unsigned int *codeBits, unsigned int maxCodeBits, const unsigned int *codeCounts, size_t nCodes) +{ + assert(nCodes > 0); + assert(nCodes <= ((size_t)1 << maxCodeBits)); + + size_t i; + SecBlockWithHint tree(nCodes); + for (i=0; i= 2) + for (i=tree.size()-2; i>=nCodes; i--) + tree[i].depth = tree[tree[i].parent].depth + 1; + unsigned int sum = 0; + SecBlockWithHint blCount(maxCodeBits+1); + std::fill(blCount.begin(), blCount.end(), 0); + for (i=treeBegin; i (unsigned int)(1 << maxCodeBits) ? sum - (1 << maxCodeBits) : 0; + + while (overflow--) + { + unsigned int bits = maxCodeBits-1; + while (blCount[bits] == 0) + bits--; + blCount[bits]--; + blCount[bits+1] += 2; + assert(blCount[maxCodeBits] > 0); + blCount[maxCodeBits]--; + } + + for (i=0; i 0); + unsigned int maxCodeBits = *std::max_element(codeBits, codeBits+nCodes); + if (maxCodeBits == 0) + return; // assume this object won't be used + + SecBlockWithHint blCount(maxCodeBits+1); + std::fill(blCount.begin(), blCount.end(), 0); + unsigned int i; + for (i=0; i nextCode(maxCodeBits+1); + nextCode[1] = 0; + for (i=2; i<=maxCodeBits; i++) + { + code = (code + blCount[i-1]) << 1; + nextCode[i] = code; + } + assert(maxCodeBits == 1 || code == (1 << maxCodeBits) - blCount[maxCodeBits]); + + m_valueToCode.resize(nCodes); + for (i=0; i> (8*sizeof(code_t)-len); + } +} + +inline void HuffmanEncoder::Encode(LowFirstBitWriter &writer, value_t value) const +{ + assert(m_valueToCode[value].len > 0); + writer.PutBits(m_valueToCode[value].code, m_valueToCode[value].len); +} + +Deflator::Deflator(BufferedTransformation *attachment, int deflateLevel, int log2WindowSize, bool detectUncompressible) + : LowFirstBitWriter(attachment) + , m_deflateLevel(-1) +{ + InitializeStaticEncoders(); + IsolatedInitialize(MakeParameters("DeflateLevel", deflateLevel)("Log2WindowSize", log2WindowSize)("DetectUncompressible", detectUncompressible)); +} + +Deflator::Deflator(const NameValuePairs ¶meters, BufferedTransformation *attachment) + : LowFirstBitWriter(attachment) + , m_deflateLevel(-1) +{ + InitializeStaticEncoders(); + IsolatedInitialize(parameters); +} + +void Deflator::InitializeStaticEncoders() +{ + unsigned int codeLengths[288]; + std::fill(codeLengths + 0, codeLengths + 144, 8); + std::fill(codeLengths + 144, codeLengths + 256, 9); + std::fill(codeLengths + 256, codeLengths + 280, 7); + std::fill(codeLengths + 280, codeLengths + 288, 8); + m_staticLiteralEncoder.Initialize(codeLengths, 288); + std::fill(codeLengths + 0, codeLengths + 32, 5); + m_staticDistanceEncoder.Initialize(codeLengths, 32); +} + +void Deflator::IsolatedInitialize(const NameValuePairs ¶meters) +{ + int log2WindowSize = parameters.GetIntValueWithDefault("Log2WindowSize", DEFAULT_LOG2_WINDOW_SIZE); + if (!(MIN_LOG2_WINDOW_SIZE <= log2WindowSize && log2WindowSize <= MAX_LOG2_WINDOW_SIZE)) + throw InvalidArgument("Deflator: " + IntToString(log2WindowSize) + " is an invalid window size"); + + m_log2WindowSize = log2WindowSize; + DSIZE = 1 << m_log2WindowSize; + DMASK = DSIZE - 1; + HSIZE = 1 << m_log2WindowSize; + HMASK = HSIZE - 1; + m_byteBuffer.New(2*DSIZE); + m_head.New(HSIZE); + m_prev.New(DSIZE); + m_matchBuffer.New(DSIZE/2); + Reset(true); + + SetDeflateLevel(parameters.GetIntValueWithDefault("DeflateLevel", DEFAULT_DEFLATE_LEVEL)); + bool detectUncompressible = parameters.GetValueWithDefault("DetectUncompressible", true); + m_compressibleDeflateLevel = detectUncompressible ? m_deflateLevel : 0; +} + +void Deflator::Reset(bool forceReset) +{ + if (forceReset) + ClearBitBuffer(); + else + assert(m_bitsBuffered == 0); + + m_headerWritten = false; + m_matchAvailable = false; + m_dictionaryEnd = 0; + m_stringStart = 0; + m_lookahead = 0; + m_minLookahead = MAX_MATCH; + m_matchBufferEnd = 0; + m_blockStart = 0; + m_blockLength = 0; + + m_detectCount = 1; + m_detectSkip = 0; + + // m_prev will be initialized automaticly in InsertString + std::fill(m_head.begin(), m_head.end(), byte(0)); + + std::fill(m_literalCounts.begin(), m_literalCounts.end(), byte(0)); + std::fill(m_distanceCounts.begin(), m_distanceCounts.end(), byte(0)); +} + +void Deflator::SetDeflateLevel(int deflateLevel) +{ + if (!(MIN_DEFLATE_LEVEL <= deflateLevel && deflateLevel <= MAX_DEFLATE_LEVEL)) + throw InvalidArgument("Deflator: " + IntToString(deflateLevel) + " is an invalid deflate level"); + + if (deflateLevel == m_deflateLevel) + return; + + EndBlock(false); + + static const unsigned int configurationTable[10][4] = { + /* good lazy nice chain */ + /* 0 */ {0, 0, 0, 0}, /* store only */ + /* 1 */ {4, 3, 8, 4}, /* maximum speed, no lazy matches */ + /* 2 */ {4, 3, 16, 8}, + /* 3 */ {4, 3, 32, 32}, + /* 4 */ {4, 4, 16, 16}, /* lazy matches */ + /* 5 */ {8, 16, 32, 32}, + /* 6 */ {8, 16, 128, 128}, + /* 7 */ {8, 32, 128, 256}, + /* 8 */ {32, 128, 258, 1024}, + /* 9 */ {32, 258, 258, 4096}}; /* maximum compression */ + + GOOD_MATCH = configurationTable[deflateLevel][0]; + MAX_LAZYLENGTH = configurationTable[deflateLevel][1]; + MAX_CHAIN_LENGTH = configurationTable[deflateLevel][3]; + + m_deflateLevel = deflateLevel; +} + +unsigned int Deflator::FillWindow(const byte *str, size_t length) +{ + unsigned int maxBlockSize = (unsigned int)STDMIN(2UL*DSIZE, 0xffffUL); + + if (m_stringStart >= maxBlockSize - MAX_MATCH) + { + if (m_blockStart < DSIZE) + EndBlock(false); + + memcpy(m_byteBuffer, m_byteBuffer + DSIZE, DSIZE); + + m_dictionaryEnd = m_dictionaryEnd < DSIZE ? 0 : m_dictionaryEnd-DSIZE; + assert(m_stringStart >= DSIZE); + m_stringStart -= DSIZE; + assert(!m_matchAvailable || m_previousMatch >= DSIZE); + m_previousMatch -= DSIZE; + assert(m_blockStart >= DSIZE); + m_blockStart -= DSIZE; + + unsigned int i; + + for (i=0; i m_stringStart+m_lookahead); + unsigned int accepted = UnsignedMin(maxBlockSize-(m_stringStart+m_lookahead), length); + assert(accepted > 0); + memcpy(m_byteBuffer + m_stringStart + m_lookahead, str, accepted); + m_lookahead += accepted; + return accepted; +} + +inline unsigned int Deflator::ComputeHash(const byte *str) const +{ + assert(str+3 <= m_byteBuffer + m_stringStart + m_lookahead); + return ((str[0] << 10) ^ (str[1] << 5) ^ str[2]) & HMASK; +} + +unsigned int Deflator::LongestMatch(unsigned int &bestMatch) const +{ + assert(m_previousLength < MAX_MATCH); + + bestMatch = 0; + unsigned int bestLength = STDMAX(m_previousLength, (unsigned int)MIN_MATCH-1); + if (m_lookahead <= bestLength) + return 0; + + const byte *scan = m_byteBuffer + m_stringStart, *scanEnd = scan + STDMIN((unsigned int)MAX_MATCH, m_lookahead); + unsigned int limit = m_stringStart > (DSIZE-MAX_MATCH) ? m_stringStart - (DSIZE-MAX_MATCH) : 0; + unsigned int current = m_head[ComputeHash(scan)]; + + unsigned int chainLength = MAX_CHAIN_LENGTH; + if (m_previousLength >= GOOD_MATCH) + chainLength >>= 2; + + while (current > limit && --chainLength > 0) + { + const byte *match = m_byteBuffer + current; + assert(scan + bestLength < m_byteBuffer + m_stringStart + m_lookahead); + if (scan[bestLength-1] == match[bestLength-1] && scan[bestLength] == match[bestLength] && scan[0] == match[0] && scan[1] == match[1]) + { + assert(scan[2] == match[2]); + unsigned int len = (unsigned int)( +#if defined(_STDEXT_BEGIN) && !(defined(_MSC_VER) && (_MSC_VER < 1400 || _MSC_VER >= 1600)) && !defined(_STLPORT_VERSION) + stdext::unchecked_mismatch +#else + std::mismatch +#endif +#if _MSC_VER >= 1600 + (stdext::make_unchecked_array_iterator(scan)+3, stdext::make_unchecked_array_iterator(scanEnd), stdext::make_unchecked_array_iterator(match)+3).first - stdext::make_unchecked_array_iterator(scan)); +#else + (scan+3, scanEnd, match+3).first - scan); +#endif + assert(len != bestLength); + if (len > bestLength) + { + bestLength = len; + bestMatch = current; + + assert(scanEnd >= scan); + if (len == (unsigned int)(scanEnd - scan)) + break; + } + } + current = m_prev[current & DMASK]; + } + return (bestMatch > 0) ? bestLength : 0; +} + +inline void Deflator::InsertString(unsigned int start) +{ + assert(start <= 0xffff); + unsigned int hash = ComputeHash(m_byteBuffer + start); + m_prev[start & DMASK] = m_head[hash]; + m_head[hash] = word16(start); +} + +void Deflator::ProcessBuffer() +{ + if (!m_headerWritten) + { + WritePrestreamHeader(); + m_headerWritten = true; + } + + if (m_deflateLevel == 0) + { + m_stringStart += m_lookahead; + m_lookahead = 0; + m_blockLength = m_stringStart - m_blockStart; + m_matchAvailable = false; + return; + } + + while (m_lookahead > m_minLookahead) + { + while (m_dictionaryEnd < m_stringStart && m_dictionaryEnd+3 <= m_stringStart+m_lookahead) + InsertString(m_dictionaryEnd++); + + if (m_matchAvailable) + { + unsigned int matchPosition = 0, matchLength = 0; + bool usePreviousMatch; + if (m_previousLength >= MAX_LAZYLENGTH) + usePreviousMatch = true; + else + { + matchLength = LongestMatch(matchPosition); + usePreviousMatch = (matchLength == 0); + } + if (usePreviousMatch) + { + MatchFound(m_stringStart-1-m_previousMatch, m_previousLength); + m_stringStart += m_previousLength-1; + m_lookahead -= m_previousLength-1; + m_matchAvailable = false; + } + else + { + m_previousLength = matchLength; + m_previousMatch = matchPosition; + LiteralByte(m_byteBuffer[m_stringStart-1]); + m_stringStart++; + m_lookahead--; + } + } + else + { + m_previousLength = 0; + m_previousLength = LongestMatch(m_previousMatch); + if (m_previousLength) + m_matchAvailable = true; + else + LiteralByte(m_byteBuffer[m_stringStart]); + m_stringStart++; + m_lookahead--; + } + + assert(m_stringStart - (m_blockStart+m_blockLength) == (unsigned int)m_matchAvailable); + } + + if (m_minLookahead == 0 && m_matchAvailable) + { + LiteralByte(m_byteBuffer[m_stringStart-1]); + m_matchAvailable = false; + } +} + +size_t Deflator::Put2(const byte *str, size_t length, int messageEnd, bool blocking) +{ + if (!blocking) + throw BlockingInputOnly("Deflator"); + + size_t accepted = 0; + while (accepted < length) + { + unsigned int newAccepted = FillWindow(str+accepted, length-accepted); + ProcessBuffer(); + // call ProcessUncompressedData() after WritePrestreamHeader() + ProcessUncompressedData(str+accepted, newAccepted); + accepted += newAccepted; + } + assert(accepted == length); + + if (messageEnd) + { + m_minLookahead = 0; + ProcessBuffer(); + EndBlock(true); + FlushBitBuffer(); + WritePoststreamTail(); + Reset(); + } + + Output(0, NULL, 0, messageEnd, blocking); + return 0; +} + +bool Deflator::IsolatedFlush(bool hardFlush, bool blocking) +{ + if (!blocking) + throw BlockingInputOnly("Deflator"); + + m_minLookahead = 0; + ProcessBuffer(); + m_minLookahead = MAX_MATCH; + EndBlock(false); + if (hardFlush) + EncodeBlock(false, STORED); + return false; +} + +void Deflator::LiteralByte(byte b) +{ + if (m_matchBufferEnd == m_matchBuffer.size()) + EndBlock(false); + + m_matchBuffer[m_matchBufferEnd++].literalCode = b; + m_literalCounts[b]++; + m_blockLength++; +} + +void Deflator::MatchFound(unsigned int distance, unsigned int length) +{ + if (m_matchBufferEnd == m_matchBuffer.size()) + EndBlock(false); + + static const unsigned int lengthCodes[] = { + 257, 258, 259, 260, 261, 262, 263, 264, 265, 265, 266, 266, 267, 267, 268, 268, + 269, 269, 269, 269, 270, 270, 270, 270, 271, 271, 271, 271, 272, 272, 272, 272, + 273, 273, 273, 273, 273, 273, 273, 273, 274, 274, 274, 274, 274, 274, 274, 274, + 275, 275, 275, 275, 275, 275, 275, 275, 276, 276, 276, 276, 276, 276, 276, 276, + 277, 277, 277, 277, 277, 277, 277, 277, 277, 277, 277, 277, 277, 277, 277, 277, + 278, 278, 278, 278, 278, 278, 278, 278, 278, 278, 278, 278, 278, 278, 278, 278, + 279, 279, 279, 279, 279, 279, 279, 279, 279, 279, 279, 279, 279, 279, 279, 279, + 280, 280, 280, 280, 280, 280, 280, 280, 280, 280, 280, 280, 280, 280, 280, 280, + 281, 281, 281, 281, 281, 281, 281, 281, 281, 281, 281, 281, 281, 281, 281, 281, + 281, 281, 281, 281, 281, 281, 281, 281, 281, 281, 281, 281, 281, 281, 281, 281, + 282, 282, 282, 282, 282, 282, 282, 282, 282, 282, 282, 282, 282, 282, 282, 282, + 282, 282, 282, 282, 282, 282, 282, 282, 282, 282, 282, 282, 282, 282, 282, 282, + 283, 283, 283, 283, 283, 283, 283, 283, 283, 283, 283, 283, 283, 283, 283, 283, + 283, 283, 283, 283, 283, 283, 283, 283, 283, 283, 283, 283, 283, 283, 283, 283, + 284, 284, 284, 284, 284, 284, 284, 284, 284, 284, 284, 284, 284, 284, 284, 284, + 284, 284, 284, 284, 284, 284, 284, 284, 284, 284, 284, 284, 284, 284, 284, 285}; + static const unsigned int lengthBases[] = {3,4,5,6,7,8,9,10,11,13,15,17,19,23,27,31,35,43,51,59,67,83,99,115,131,163,195,227,258}; + static const unsigned int distanceBases[30] = + {1,2,3,4,5,7,9,13,17,25,33,49,65,97,129,193,257,385,513,769,1025,1537,2049,3073,4097,6145,8193,12289,16385,24577}; + + EncodedMatch &m = m_matchBuffer[m_matchBufferEnd++]; + assert(length >= 3); + unsigned int lengthCode = lengthCodes[length-3]; + m.literalCode = lengthCode; + m.literalExtra = length - lengthBases[lengthCode-257]; + unsigned int distanceCode = (unsigned int)(std::upper_bound(distanceBases, distanceBases+30, distance) - distanceBases - 1); + m.distanceCode = distanceCode; + m.distanceExtra = distance - distanceBases[distanceCode]; + + m_literalCounts[lengthCode]++; + m_distanceCounts[distanceCode]++; + m_blockLength += length; +} + +inline unsigned int CodeLengthEncode(const unsigned int *begin, + const unsigned int *end, + const unsigned int *& p, + unsigned int &extraBits, + unsigned int &extraBitsLength) +{ + unsigned int v = *p; + if ((end-p) >= 3) + { + const unsigned int *oldp = p; + if (v==0 && p[1]==0 && p[2]==0) + { + for (p=p+3; p!=end && *p==0 && p!=oldp+138; p++) {} + unsigned int repeat = (unsigned int)(p - oldp); + if (repeat <= 10) + { + extraBits = repeat-3; + extraBitsLength = 3; + return 17; + } + else + { + extraBits = repeat-11; + extraBitsLength = 7; + return 18; + } + } + else if (p!=begin && v==p[-1] && v==p[1] && v==p[2]) + { + for (p=p+3; p!=end && *p==v && p!=oldp+6; p++) {} + unsigned int repeat = (unsigned int)(p - oldp); + extraBits = repeat-3; + extraBitsLength = 2; + return 16; + } + } + p++; + extraBits = 0; + extraBitsLength = 0; + return v; +} + +void Deflator::EncodeBlock(bool eof, unsigned int blockType) +{ + PutBits(eof, 1); + PutBits(blockType, 2); + + if (blockType == STORED) + { + assert(m_blockStart + m_blockLength <= m_byteBuffer.size()); + assert(m_blockLength <= 0xffff); + FlushBitBuffer(); + AttachedTransformation()->PutWord16(word16(m_blockLength), LITTLE_ENDIAN_ORDER); + AttachedTransformation()->PutWord16(word16(~m_blockLength), LITTLE_ENDIAN_ORDER); + AttachedTransformation()->Put(m_byteBuffer + m_blockStart, m_blockLength); + } + else + { + if (blockType == DYNAMIC) + { +#if defined(_MSC_VER) && !defined(__MWERKS__) && (_MSC_VER <= 1300) + // VC60 and VC7 workaround: built-in std::reverse_iterator has two template parameters, Dinkumware only has one + typedef reverse_bidirectional_iterator RevIt; +#elif defined(_RWSTD_NO_CLASS_PARTIAL_SPEC) + typedef std::reverse_iterator RevIt; +#else + typedef std::reverse_iterator RevIt; +#endif + + FixedSizeSecBlock literalCodeLengths; + FixedSizeSecBlock distanceCodeLengths; + + m_literalCounts[256] = 1; + HuffmanEncoder::GenerateCodeLengths(literalCodeLengths, 15, m_literalCounts, 286); + m_dynamicLiteralEncoder.Initialize(literalCodeLengths, 286); + unsigned int hlit = (unsigned int)(std::find_if(RevIt(literalCodeLengths.end()), RevIt(literalCodeLengths.begin()+257), std::bind2nd(std::not_equal_to(), 0)).base() - (literalCodeLengths.begin()+257)); + + HuffmanEncoder::GenerateCodeLengths(distanceCodeLengths, 15, m_distanceCounts, 30); + m_dynamicDistanceEncoder.Initialize(distanceCodeLengths, 30); + unsigned int hdist = (unsigned int)(std::find_if(RevIt(distanceCodeLengths.end()), RevIt(distanceCodeLengths.begin()+1), std::bind2nd(std::not_equal_to(), 0)).base() - (distanceCodeLengths.begin()+1)); + + SecBlockWithHint combinedLengths(hlit+257+hdist+1); + memcpy(combinedLengths, literalCodeLengths, (hlit+257)*sizeof(unsigned int)); + memcpy(combinedLengths+hlit+257, distanceCodeLengths, (hdist+1)*sizeof(unsigned int)); + + FixedSizeSecBlock codeLengthCodeCounts, codeLengthCodeLengths; + std::fill(codeLengthCodeCounts.begin(), codeLengthCodeCounts.end(), 0); + const unsigned int *p = combinedLengths.begin(), *begin = combinedLengths.begin(), *end = combinedLengths.end(); + while (p != end) + { + unsigned int code=0, extraBits=0, extraBitsLength=0; + code = CodeLengthEncode(begin, end, p, extraBits, extraBitsLength); + codeLengthCodeCounts[code]++; + } + HuffmanEncoder::GenerateCodeLengths(codeLengthCodeLengths, 7, codeLengthCodeCounts, 19); + HuffmanEncoder codeLengthEncoder(codeLengthCodeLengths, 19); + static const unsigned int border[] = { // Order of the bit length code lengths + 16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15}; + unsigned int hclen = 19; + while (hclen > 4 && codeLengthCodeLengths[border[hclen-1]] == 0) + hclen--; + hclen -= 4; + + PutBits(hlit, 5); + PutBits(hdist, 5); + PutBits(hclen, 4); + + for (unsigned int i=0; i= 257) + { + assert(literalCode <= 285); + PutBits(m_matchBuffer[i].literalExtra, lengthExtraBits[literalCode-257]); + unsigned int distanceCode = m_matchBuffer[i].distanceCode; + distanceEncoder.Encode(*this, distanceCode); + PutBits(m_matchBuffer[i].distanceExtra, distanceExtraBits[distanceCode]); + } + } + literalEncoder.Encode(*this, 256); // end of block + } +} + +void Deflator::EndBlock(bool eof) +{ + if (m_blockLength == 0 && !eof) + return; + + if (m_deflateLevel == 0) + { + EncodeBlock(eof, STORED); + + if (m_compressibleDeflateLevel > 0 && ++m_detectCount == m_detectSkip) + { + m_deflateLevel = m_compressibleDeflateLevel; + m_detectCount = 1; + } + } + else + { + unsigned long storedLen = 8*((unsigned long)m_blockLength+4) + RoundUpToMultipleOf(m_bitsBuffered+3, 8U)-m_bitsBuffered; + + StartCounting(); + EncodeBlock(eof, STATIC); + unsigned long staticLen = FinishCounting(); + + unsigned long dynamicLen; + if (m_blockLength < 128 && m_deflateLevel < 8) + dynamicLen = ULONG_MAX; + else + { + StartCounting(); + EncodeBlock(eof, DYNAMIC); + dynamicLen = FinishCounting(); + } + + if (storedLen <= staticLen && storedLen <= dynamicLen) + { + EncodeBlock(eof, STORED); + + if (m_compressibleDeflateLevel > 0) + { + if (m_detectSkip) + m_deflateLevel = 0; + m_detectSkip = m_detectSkip ? STDMIN(2*m_detectSkip, 128U) : 1; + } + } + else + { + if (staticLen <= dynamicLen) + EncodeBlock(eof, STATIC); + else + EncodeBlock(eof, DYNAMIC); + + if (m_compressibleDeflateLevel > 0) + m_detectSkip = 0; + } + } + + m_matchBufferEnd = 0; + m_blockStart += m_blockLength; + m_blockLength = 0; + std::fill(m_literalCounts.begin(), m_literalCounts.end(), 0); + std::fill(m_distanceCounts.begin(), m_distanceCounts.end(), 0); +} + +NAMESPACE_END -- cgit v1.2.1