p7zip/CPP/7zip/Compress/DeflateDecoder.cpp
2017-10-11 12:35:36 +02:00

418 lines
10 KiB
C++

// DeflateDecoder.cpp
#include "StdAfx.h"
#include "DeflateDecoder.h"
namespace NCompress {
namespace NDeflate {
namespace NDecoder {
CCoder::CCoder(bool deflate64Mode, bool deflateNSIS):
_deflate64Mode(deflate64Mode),
_deflateNSIS(deflateNSIS),
_keepHistory(false),
_needFinishInput(false),
_needInitInStream(true),
ZlibMode(false) {}
UInt32 CCoder::ReadBits(unsigned numBits)
{
return m_InBitStream.ReadBits(numBits);
}
Byte CCoder::ReadAlignedByte()
{
return m_InBitStream.ReadAlignedByte();
}
bool CCoder::DecodeLevels(Byte *levels, unsigned numSymbols)
{
unsigned i = 0;
do
{
UInt32 sym = m_LevelDecoder.Decode(&m_InBitStream);
if (sym < kTableDirectLevels)
levels[i++] = (Byte)sym;
else
{
if (sym >= kLevelTableSize)
return false;
unsigned num;
unsigned numBits;
Byte symbol;
if (sym == kTableLevelRepNumber)
{
if (i == 0)
return false;
numBits = 2;
num = 0;
symbol = levels[i - 1];
}
else
{
sym -= kTableLevel0Number;
sym <<= 2;
numBits = 3 + (unsigned)sym;
num = ((unsigned)sym << 1);
symbol = 0;
}
num += i + 3 + ReadBits(numBits);
if (num > numSymbols)
return false;
do
levels[i++] = symbol;
while (i < num);
}
}
while (i < numSymbols);
return true;
}
#define RIF(x) { if (!(x)) return false; }
bool CCoder::ReadTables(void)
{
m_FinalBlock = (ReadBits(kFinalBlockFieldSize) == NFinalBlockField::kFinalBlock);
if (m_InBitStream.ExtraBitsWereRead())
return false;
UInt32 blockType = ReadBits(kBlockTypeFieldSize);
if (blockType > NBlockType::kDynamicHuffman)
return false;
if (m_InBitStream.ExtraBitsWereRead())
return false;
if (blockType == NBlockType::kStored)
{
m_StoredMode = true;
m_InBitStream.AlignToByte();
m_StoredBlockSize = ReadAligned_UInt16(); // ReadBits(kStoredBlockLengthFieldSize)
if (_deflateNSIS)
return true;
return (m_StoredBlockSize == (UInt16)~ReadAligned_UInt16());
}
m_StoredMode = false;
CLevels levels;
if (blockType == NBlockType::kFixedHuffman)
{
levels.SetFixedLevels();
_numDistLevels = _deflate64Mode ? kDistTableSize64 : kDistTableSize32;
}
else
{
unsigned numLitLenLevels = ReadBits(kNumLenCodesFieldSize) + kNumLitLenCodesMin;
_numDistLevels = ReadBits(kNumDistCodesFieldSize) + kNumDistCodesMin;
unsigned numLevelCodes = ReadBits(kNumLevelCodesFieldSize) + kNumLevelCodesMin;
if (!_deflate64Mode)
if (_numDistLevels > kDistTableSize32)
return false;
Byte levelLevels[kLevelTableSize];
for (unsigned i = 0; i < kLevelTableSize; i++)
{
unsigned position = kCodeLengthAlphabetOrder[i];
if (i < numLevelCodes)
levelLevels[position] = (Byte)ReadBits(kLevelFieldSize);
else
levelLevels[position] = 0;
}
if (m_InBitStream.ExtraBitsWereRead())
return false;
RIF(m_LevelDecoder.Build(levelLevels));
Byte tmpLevels[kFixedMainTableSize + kFixedDistTableSize];
if (!DecodeLevels(tmpLevels, numLitLenLevels + _numDistLevels))
return false;
if (m_InBitStream.ExtraBitsWereRead())
return false;
levels.SubClear();
memcpy(levels.litLenLevels, tmpLevels, numLitLenLevels);
memcpy(levels.distLevels, tmpLevels + numLitLenLevels, _numDistLevels);
}
RIF(m_MainDecoder.Build(levels.litLenLevels));
return m_DistDecoder.Build(levels.distLevels);
}
HRESULT CCoder::CodeSpec(UInt32 curSize, bool finishInputStream)
{
if (_remainLen == kLenIdFinished)
return S_OK;
if (_remainLen == kLenIdNeedInit)
{
if (!_keepHistory)
if (!m_OutWindowStream.Create(_deflate64Mode ? kHistorySize64: kHistorySize32))
return E_OUTOFMEMORY;
RINOK(InitInStream(_needInitInStream));
m_OutWindowStream.Init(_keepHistory);
m_FinalBlock = false;
_remainLen = 0;
_needReadTable = true;
}
while (_remainLen > 0 && curSize > 0)
{
_remainLen--;
Byte b = m_OutWindowStream.GetByte(_rep0);
m_OutWindowStream.PutByte(b);
curSize--;
}
while (curSize > 0 || finishInputStream)
{
if (m_InBitStream.ExtraBitsWereRead())
return S_FALSE;
if (_needReadTable)
{
if (m_FinalBlock)
{
_remainLen = kLenIdFinished;
break;
}
if (!ReadTables())
return S_FALSE;
if (m_InBitStream.ExtraBitsWereRead())
return S_FALSE;
_needReadTable = false;
}
if (m_StoredMode)
{
if (finishInputStream && curSize == 0 && m_StoredBlockSize != 0)
return S_FALSE;
/* NSIS version contains some bits in bitl bits buffer.
So we must read some first bytes via ReadAlignedByte */
for (; m_StoredBlockSize > 0 && curSize > 0 && m_InBitStream.ThereAreDataInBitsBuffer(); m_StoredBlockSize--, curSize--)
m_OutWindowStream.PutByte(ReadAlignedByte());
for (; m_StoredBlockSize > 0 && curSize > 0; m_StoredBlockSize--, curSize--)
m_OutWindowStream.PutByte(m_InBitStream.ReadDirectByte());
_needReadTable = (m_StoredBlockSize == 0);
continue;
}
while (curSize > 0)
{
if (m_InBitStream.ExtraBitsWereRead_Fast())
return S_FALSE;
UInt32 sym = m_MainDecoder.Decode(&m_InBitStream);
if (sym < 0x100)
{
m_OutWindowStream.PutByte((Byte)sym);
curSize--;
continue;
}
else if (sym == kSymbolEndOfBlock)
{
_needReadTable = true;
break;
}
else if (sym < kMainTableSize)
{
sym -= kSymbolMatch;
UInt32 len;
{
unsigned numBits;
if (_deflate64Mode)
{
len = kLenStart64[sym];
numBits = kLenDirectBits64[sym];
}
else
{
len = kLenStart32[sym];
numBits = kLenDirectBits32[sym];
}
len += kMatchMinLen + m_InBitStream.ReadBits(numBits);
}
UInt32 locLen = len;
if (locLen > curSize)
locLen = (UInt32)curSize;
sym = m_DistDecoder.Decode(&m_InBitStream);
if (sym >= _numDistLevels)
return S_FALSE;
UInt32 distance = kDistStart[sym] + m_InBitStream.ReadBits(kDistDirectBits[sym]);
if (!m_OutWindowStream.CopyBlock(distance, locLen))
return S_FALSE;
curSize -= locLen;
len -= locLen;
if (len != 0)
{
_remainLen = (Int32)len;
_rep0 = distance;
break;
}
}
else
return S_FALSE;
}
if (finishInputStream && curSize == 0)
{
if (m_MainDecoder.Decode(&m_InBitStream) != kSymbolEndOfBlock)
return S_FALSE;
_needReadTable = true;
}
}
if (m_InBitStream.ExtraBitsWereRead())
return S_FALSE;
return S_OK;
}
#ifdef _NO_EXCEPTIONS
#define DEFLATE_TRY_BEGIN
#define DEFLATE_TRY_END(res)
#else
#define DEFLATE_TRY_BEGIN try {
#define DEFLATE_TRY_END(res) } \
catch(const CInBufferException &e) { res = e.ErrorCode; } \
catch(const CLzOutWindowException &e) { res = e.ErrorCode; } \
catch(...) { res = S_FALSE; }
#endif
HRESULT CCoder::CodeReal(ISequentialOutStream *outStream,
const UInt64 *outSize, ICompressProgressInfo *progress)
{
HRESULT res;
DEFLATE_TRY_BEGIN
m_OutWindowStream.SetStream(outStream);
CCoderReleaser flusher(this);
const UInt64 inStart = _needInitInStream ? 0 : m_InBitStream.GetProcessedSize();
const UInt64 start = m_OutWindowStream.GetProcessedSize();
for (;;)
{
UInt32 curSize = 1 << 18;
bool finishInputStream = false;
if (outSize)
{
const UInt64 rem = *outSize - (m_OutWindowStream.GetProcessedSize() - start);
if (curSize >= rem)
{
curSize = (UInt32)rem;
if (ZlibMode || _needFinishInput)
finishInputStream = true;
}
}
if (!finishInputStream && curSize == 0)
break;
RINOK(CodeSpec(curSize, finishInputStream));
if (_remainLen == kLenIdFinished)
break;
if (progress)
{
const UInt64 inSize = m_InBitStream.GetProcessedSize() - inStart;
const UInt64 nowPos64 = m_OutWindowStream.GetProcessedSize() - start;
RINOK(progress->SetRatioInfo(&inSize, &nowPos64));
}
}
if (_remainLen == kLenIdFinished && ZlibMode)
{
m_InBitStream.AlignToByte();
for (unsigned i = 0; i < 4; i++)
ZlibFooter[i] = ReadAlignedByte();
}
flusher.NeedFlush = false;
res = Flush();
if (res == S_OK && _remainLen != kLenIdNeedInit && InputEofError())
return S_FALSE;
DEFLATE_TRY_END(res)
return res;
}
HRESULT CCoder::Code(ISequentialInStream *inStream, ISequentialOutStream *outStream,
const UInt64 * /* inSize */, const UInt64 *outSize, ICompressProgressInfo *progress)
{
SetInStream(inStream);
SetOutStreamSize(outSize);
HRESULT res = CodeReal(outStream, outSize, progress);
ReleaseInStream();
return res;
}
STDMETHODIMP CCoder::GetInStreamProcessedSize(UInt64 *value)
{
if (!value)
return E_INVALIDARG;
*value = m_InBitStream.GetProcessedSize();
return S_OK;
}
STDMETHODIMP CCoder::SetInStream(ISequentialInStream *inStream)
{
m_InStreamRef = inStream;
m_InBitStream.SetStream(inStream);
return S_OK;
}
STDMETHODIMP CCoder::ReleaseInStream()
{
m_InStreamRef.Release();
return S_OK;
}
STDMETHODIMP CCoder::SetOutStreamSize(const UInt64 * /* outSize */)
{
_remainLen = kLenIdNeedInit;
_needInitInStream = true;
m_OutWindowStream.Init(_keepHistory);
return S_OK;
}
#ifndef NO_READ_FROM_CODER
STDMETHODIMP CCoder::Read(void *data, UInt32 size, UInt32 *processedSize)
{
HRESULT res;
DEFLATE_TRY_BEGIN
if (processedSize)
*processedSize = 0;
const UInt64 startPos = m_OutWindowStream.GetProcessedSize();
m_OutWindowStream.SetMemStream((Byte *)data);
res = CodeSpec(size, false);
if (res == S_OK)
{
res = Flush();
if (processedSize)
*processedSize = (UInt32)(m_OutWindowStream.GetProcessedSize() - startPos);
}
DEFLATE_TRY_END(res)
m_OutWindowStream.SetMemStream(NULL);
return res;
}
#endif
STDMETHODIMP CCoder::CodeResume(ISequentialOutStream *outStream, const UInt64 *outSize, ICompressProgressInfo *progress)
{
_remainLen = kLenIdNeedInit;
m_OutWindowStream.Init(_keepHistory);
return CodeReal(outStream, outSize, progress);
}
}}}