STDMETHODIMP CDecoder::CodeReal(ISequentialInStream *inStream, ISequentialOutStream *outStream, const UInt64 * /* inSize */, const UInt64 * /* outSize */, ICompressProgressInfo *progress) { NStream::NLSBF::CBaseDecoder<CInBuffer> inBuffer; COutBuffer outBuffer; if (!inBuffer.Create(kBufferSize)) return E_OUTOFMEMORY; inBuffer.SetStream(inStream); inBuffer.Init(); if (!outBuffer.Create(kBufferSize)) return E_OUTOFMEMORY; outBuffer.SetStream(outStream); outBuffer.Init(); int maxbits = _properties & kNumBitsMask; if (maxbits < kNumMinBits || maxbits > kNumMaxBits) return S_FALSE; UInt32 numItems = 1 << maxbits; bool blockMode = ((_properties & kBlockModeMask) != 0); if (!blockMode) return E_NOTIMPL; if (maxbits != _numMaxBits || _parents == 0 || _suffixes == 0 || _stack == 0) { if (!Alloc(numItems)) return E_OUTOFMEMORY; _numMaxBits = maxbits; } UInt64 prevPos = 0; int numBits = kNumMinBits; UInt32 head = blockMode ? 257 : 256; bool needPrev = false; int keepBits = 0; _parents[256] = 0; // virus protection _suffixes[256] = 0; for (;;) { if (keepBits < numBits) keepBits = numBits * 8; UInt32 symbol = inBuffer.ReadBits(numBits); if (inBuffer.ExtraBitsWereRead()) break; keepBits -= numBits; if (symbol >= head) return S_FALSE; if (blockMode && symbol == 256) { for (;keepBits > 0; keepBits--) inBuffer.ReadBits(1); numBits = kNumMinBits; head = 257; needPrev = false; continue; } UInt32 cur = symbol; int i = 0; while (cur >= 256) { _stack[i++] = _suffixes[cur]; cur = _parents[cur]; } _stack[i++] = (Byte)cur; if (needPrev) { _suffixes[head - 1] = (Byte)cur; if (symbol == head - 1) _stack[0] = (Byte)cur; } while (i > 0) outBuffer.WriteByte((_stack[--i])); if (head < numItems) { needPrev = true; _parents[head++] = (UInt16)symbol; if (head > ((UInt32)1 << numBits)) { if (numBits < maxbits) { numBits++; keepBits = numBits * 8; } } } else needPrev = false; UInt64 nowPos = outBuffer.GetProcessedSize(); if (progress != NULL && nowPos - prevPos > (1 << 18)) { prevPos = nowPos; UInt64 packSize = inBuffer.GetProcessedSize(); RINOK(progress->SetRatioInfo(&packSize, &nowPos)); } } return outBuffer.Flush(); }
STDMETHODIMP CDecoder ::CodeReal(ISequentialInStream *inStream, ISequentialOutStream *outStream, const UInt64 * /* inSize */, const UInt64 * /* outSize */, ICompressProgressInfo *progress) { NStream::NLSBF::CBaseDecoder<CInBuffer> inBuffer; COutBuffer outBuffer; if (!inBuffer.Create(kBufferSize)) return E_OUTOFMEMORY; inBuffer.SetStream(inStream); inBuffer.Init(); if (!outBuffer.Create(kBufferSize)) return E_OUTOFMEMORY; outBuffer.SetStream(outStream); outBuffer.Init(); UInt64 prevPos = 0; int numBits = kNumMinBits; UInt32 head = 257; bool needPrev = false; _parents[256] = 0; // virus protection _suffixes[256] = 0; int i; for (i = 0; i < 257; i++) _isFree[i] = false; for (; i < kNumItems; i++) _isFree[i] = true; UInt32 lastSymbol = 0; for (;;) { outBuffer.Flush(); UInt32 symbol = inBuffer.ReadBits(numBits); if (inBuffer.ExtraBitsWereRead()) break; if (_isFree[symbol]) return S_FALSE; if (symbol == 256) { // fix it; UInt32 symbol = inBuffer.ReadBits(numBits); if (symbol == 1) { if (numBits < kNumMaxBits) numBits++; } else if (symbol == 2) { /* maybe need delete prev also ? if (needPrev) _isFree[head - 1] = true; */ for (i = 257; i < kNumItems; i++) _isParent[i] = false; for (i = 257; i < kNumItems; i++) if (!_isFree[i]) _isParent[_parents[i]] = true; for (i = 257; i < kNumItems; i++) if (!_isParent[i]) _isFree[i] = true; head = 257; while(head < ((UInt32)1 << numBits) && !_isFree[head]) head++; if (head < ((UInt32)1 << numBits)) { needPrev = true; _isFree[head] = false; _parents[head] = (UInt16)lastSymbol; head++; } } else return S_FALSE; continue; } UInt32 cur = symbol; i = 0; while (cur >= 256) { _stack[i++] = _suffixes[cur]; cur = _parents[cur]; } _stack[i++] = (Byte)cur; if (needPrev) { _suffixes[head - 1] = (Byte)cur; if (symbol == head - 1) _stack[0] = (Byte)cur; } while (i > 0) outBuffer.WriteByte((_stack[--i])); while(head < ((UInt32)1 << numBits) && !_isFree[head]) head++; if (head < ((UInt32)1 << numBits)) { needPrev = true; _isFree[head] = false; _parents[head] = (UInt16)symbol; head++; } else needPrev = false; lastSymbol = symbol; UInt64 nowPos = outBuffer.GetProcessedSize(); if (progress != NULL && nowPos - prevPos > (1 << 18)) { prevPos = nowPos; UInt64 packSize = inBuffer.GetProcessedSize(); RINOK(progress->SetRatioInfo(&packSize, &nowPos)); } } return outBuffer.Flush(); }