4.44 beta

CPP/7zip/Compress/Lzh/LzhDecoder.cpp

@@ -0,0 +1,216 @@
+// LzhDecoder.cpp
+
+#include "StdAfx.h"
+
+#include "LzhDecoder.h"
+
+#include "Windows/Defs.h"
+
+namespace NCompress{
+namespace NLzh {
+namespace NDecoder {
+
+static const UInt32 kHistorySize = (1 << 16);
+
+static const int kBlockSizeBits = 16;
+static const int kNumCBits = 9;
+static const int kNumLevelBits = 5; // smallest integer such that (1 << kNumLevelBits) > kNumLevelSymbols/
+
+UInt32 CCoder::ReadBits(int numBits) {  return m_InBitStream.ReadBits(numBits); }
+
+HRESULT CCoder::ReadLevelTable()
+{
+  int n = ReadBits(kNumLevelBits);
+  if (n == 0) 
+  {
+    m_LevelHuffman.Symbol = ReadBits(kNumLevelBits);
+    if (m_LevelHuffman.Symbol >= kNumLevelSymbols)
+      return S_FALSE;
+  }
+  else 
+  {
+    if (n > kNumLevelSymbols)
+      return S_FALSE;
+    m_LevelHuffman.Symbol = -1;
+    Byte lens[kNumLevelSymbols];
+    int i = 0;
+    while (i < n) 
+    {
+      int c = m_InBitStream.ReadBits(3);
+      if (c == 7) 
+        while (ReadBits(1)) 
+          if (c++ > kMaxHuffmanLen)
+            return S_FALSE;
+      lens[i++] = (Byte)c;
+      if (i == kNumSpecLevelSymbols) 
+      {
+        c = ReadBits(2);
+        while (--c >= 0)
+          lens[i++] = 0;
+      }
+    }
+    while (i < kNumLevelSymbols)
+      lens[i++] = 0;
+    m_LevelHuffman.SetCodeLengths(lens);
+  }
+  return S_OK;
+}
+
+HRESULT CCoder::ReadPTable(int numBits)
+{
+  int n = ReadBits(numBits);
+  if (n == 0)
+  {
+    m_PHuffmanDecoder.Symbol = ReadBits(numBits);
+    if (m_PHuffmanDecoder.Symbol >= kNumDistanceSymbols)
+      return S_FALSE;
+  }
+  else 
+  {
+    if (n > kNumDistanceSymbols)
+      return S_FALSE;
+    m_PHuffmanDecoder.Symbol = -1;
+    Byte lens[kNumDistanceSymbols];
+    int i = 0;
+    while (i < n) 
+    {
+      int c = m_InBitStream.ReadBits(3);
+      if (c == 7) 
+        while (ReadBits(1)) 
+        {
+          if (c > kMaxHuffmanLen)
+            return S_FALSE;
+          c++;
+        }
+      lens[i++] = (Byte)c;
+    }
+    while (i < kNumDistanceSymbols)
+      lens[i++] = 0;
+    m_PHuffmanDecoder.SetCodeLengths(lens);
+  }
+  return S_OK;
+}
+
+HRESULT CCoder::ReadCTable()
+{
+  int n = ReadBits(kNumCBits);
+  if (n == 0) 
+  {
+    m_CHuffmanDecoder.Symbol = ReadBits(kNumCBits);
+    if (m_CHuffmanDecoder.Symbol >= kNumCSymbols)
+      return S_FALSE;
+  }
+  else 
+  {
+    if (n > kNumCSymbols)
+      return S_FALSE;
+    m_CHuffmanDecoder.Symbol = -1;
+    Byte lens[kNumCSymbols];
+    int i = 0;
+    while (i < n) 
+    {
+      int c = m_LevelHuffman.Decode(&m_InBitStream);
+      if (c < kNumSpecLevelSymbols) 
+      {
+        if (c == 0)
+          c = 1;
+        else if (c == 1)
+          c = ReadBits(4) + 3;
+        else
+          c = ReadBits(kNumCBits) + 20;
+        while (--c >= 0)
+        {
+          if (i > kNumCSymbols)
+            return S_FALSE;
+          lens[i++] = 0;
+        }
+      }
+      else
+        lens[i++] = (Byte)(c - 2);
+    }
+    while (i < kNumCSymbols)
+      lens[i++] = 0;
+    m_CHuffmanDecoder.SetCodeLengths(lens);
+  }
+  return S_OK;
+}
+
+STDMETHODIMP CCoder::CodeReal(ISequentialInStream *inStream,
+    ISequentialOutStream *outStream, const UInt64 * /* inSize */, const UInt64 *outSize,
+    ICompressProgressInfo *progress)
+{
+  if (outSize == NULL)
+    return E_INVALIDARG;
+
+  if (!m_OutWindowStream.Create(kHistorySize))
+    return E_OUTOFMEMORY;
+  if (!m_InBitStream.Create(1 << 20))
+    return E_OUTOFMEMORY;
+
+  UInt64 pos = 0;
+  m_OutWindowStream.SetStream(outStream);
+  m_OutWindowStream.Init(false);
+  m_InBitStream.SetStream(inStream);
+  m_InBitStream.Init();
+  
+  CCoderReleaser coderReleaser(this);
+
+  int pbit;
+  if (m_NumDictBits <= 13)  
+    pbit = 4;
+  else   
+    pbit = 5;
+
+  UInt32 blockSize = 0;
+
+  while(pos < *outSize)
+  {
+    // for (i = 0; i < dictSize; i++) dtext[i] = 0x20;
+    
+    if (blockSize == 0) 
+    {
+      if (progress != NULL)
+      {
+        UInt64 packSize = m_InBitStream.GetProcessedSize();
+        RINOK(progress->SetRatioInfo(&packSize, &pos));
+      }
+      blockSize = ReadBits(kBlockSizeBits);
+      ReadLevelTable();
+      ReadCTable();
+      RINOK(ReadPTable(pbit));
+    }
+    blockSize--;
+    UInt32 c = m_CHuffmanDecoder.Decode(&m_InBitStream);
+    if (c < 256) 
+    {
+      m_OutWindowStream.PutByte((Byte)c);
+      pos++;
+    }
+    else 
+    {
+      // offset = (interface->method == LARC_METHOD_NUM) ? 0x100 - 2 : 0x100 - 3;
+      UInt32 len  = c - 256 + kMinMatch;
+      UInt32 distance = m_PHuffmanDecoder.Decode(&m_InBitStream);
+      if (distance != 0)
+        distance = (1 << (distance - 1)) + ReadBits(distance - 1);
+      pos += len;
+      if (distance >= pos)
+        throw 1;
+      m_OutWindowStream.CopyBlock(distance, len);
+    }
+  }
+  coderReleaser.NeedFlush = false;
+  return m_OutWindowStream.Flush();
+}
+
+STDMETHODIMP CCoder::Code(ISequentialInStream *inStream,
+    ISequentialOutStream *outStream, const UInt64 *inSize, const UInt64 *outSize,
+    ICompressProgressInfo *progress)
+{
+  try { return CodeReal(inStream, outStream, inSize, outSize, progress);}
+  catch(const CInBufferException &e) { return e.ErrorCode; }
+  catch(const CLZOutWindowException &e) { return e.ErrorCode; }
+  catch(...) { return S_FALSE; }
+}
+
+}}}