3.13

2025-12-14 08:11:35 -06:00 · 2003-12-11 00:00:00 +00:00
commit 8c1b5c7b7e
982 changed files with 118799 additions and 0 deletions
--- a/7zip/Archive/Cab/LZXBitDecoder.h
+++ b/7zip/Archive/Cab/LZXBitDecoder.h
@@ -0,0 +1,112 @@
+// Archive/Cab/LZXBitDecoder.h
+
+#ifndef __ARCHIVE_CAB_LZXBITDECODER_H
+#define __ARCHIVE_CAB_LZXBITDECODER_H
+
+#include "CabInBuffer.h"
+
+namespace NArchive {
+namespace NCab {
+namespace NLZX {
+namespace NBitStream {
+
+const int kNumBigValueBits = 8 * 4;
+
+const int kNumValueBits = 17;
+const int kBitDecoderValueMask = (1 << kNumValueBits) - 1;
+
+class CDecoder
+{
+protected:
+  CInBuffer m_Stream;
+  UINT32 m_BitPos;
+  UINT32 m_Value;
+public:
+  void InitStream(ISequentialInStream *aStream, BYTE aReservedSize, UINT32 aNumBlocks)
+    { 
+      m_Stream.Init(aStream, aReservedSize, aNumBlocks);
+    }
+  /*
+  void ReleaseStream()
+    { m_Stream.ReleaseStream(); }
+  */
+  UINT64 GetProcessedSize() const 
+    { return m_Stream.GetProcessedSize() - (kNumBigValueBits - m_BitPos) / 8; }
+  UINT32 GetBitPosition() const
+    { return UINT32(m_Stream.GetProcessedSize() * 8 - (kNumBigValueBits - m_BitPos)); }
+  
+  void Init()
+  {
+    m_BitPos = kNumBigValueBits; 
+    Normalize();
+  }
+
+  void Normalize()
+  {
+    for (;m_BitPos >= 16; m_BitPos -= 16)
+    {
+      BYTE aByte0 = m_Stream.ReadByte();
+      BYTE aByte1 = m_Stream.ReadByte();
+      m_Value = (m_Value << 8) | aByte1;
+      m_Value = (m_Value << 8) | aByte0;
+    }
+  }
+
+  UINT32 GetValue(UINT32 aNumBits)
+  {
+    return ((m_Value >> ((32 - kNumValueBits) - m_BitPos)) & kBitDecoderValueMask) >> 
+        (kNumValueBits - aNumBits);
+  }
+  
+  void MovePos(UINT32 aNumBits)
+  {
+    m_BitPos += aNumBits;
+    Normalize();
+  }
+  
+  UINT32 ReadBits(UINT32 aNumBits)
+  {
+    UINT32 aRes = GetValue(aNumBits);
+    MovePos(aNumBits);
+    return aRes;
+  }
+  UINT32 ReadBitsBig(UINT32 aNumBits)
+  {
+    UINT32 aNumBits0 = aNumBits / 2;
+    UINT32 aNumBits1 = aNumBits - aNumBits0;
+    UINT32 aRes = ReadBits(aNumBits0) << aNumBits1;
+    return aRes + ReadBits(aNumBits1);
+  }
+
+  BYTE DirectReadByte()
+  {
+    if (m_BitPos == kNumBigValueBits)
+      return m_Stream.ReadByte();
+    BYTE aRes;
+    switch(m_BitPos)
+    {
+      case 0:
+        aRes = BYTE(m_Value >> 16);
+        break;
+      case 8:
+        aRes = BYTE(m_Value >> 24);
+        break;
+      case 16:
+        aRes = BYTE(m_Value);
+        break;
+      case 24:
+        aRes = BYTE(m_Value >> 8);
+        break;
+    }
+    m_BitPos += 8;
+    return aRes;
+  }
+
+  HRESULT ReadBlock(UINT32 &anUncompressedSize, bool &aDataAreCorrect)
+    { return m_Stream.ReadBlock(anUncompressedSize, aDataAreCorrect); }
+};
+
+
+}}}}
+
+#endif