9.34

CPP/7zip/Archive/Cab/CabBlockInStream.cpp

@@ -3,8 +3,7 @@
 #include "StdAfx.h"
 
 #include "../../../../C/Alloc.h"
-
-#include "Common/Defs.h"
+#include "../../../../C/CpuArch.h"
 
 #include "../../Common/StreamUtils.h"
 
@@ -17,173 +16,73 @@ static const UInt32 kBlockSize = (1 << 16);
 
 bool CCabBlockInStream::Create()
 {
-  if (!_buffer)
-    _buffer = (Byte *)::MyAlloc(kBlockSize);
-  return (_buffer != 0);
+  if (!_buf)
+    _buf = (Byte *)::MyAlloc(kBlockSize);
+  return _buf != 0;
 }
 
 CCabBlockInStream::~CCabBlockInStream()
 {
-  MyFree(_buffer);
+  ::MyFree(_buf);
 }
 
-class CCheckSum2
+static UInt32 CheckSum(const Byte *p, UInt32 size)
 {
-  UInt32 m_Value;
-  int m_Pos;
-  Byte m_Hist[4];
-public:
-  CCheckSum2(): m_Value(0){};
-  void Init() { m_Value = 0;  m_Pos = 0; }
-  void Update(const void *data, UInt32 size);
-  void FinishDataUpdate()
+  UInt32 sum = 0;
+  for (UInt32 i = size >> 2; i != 0; i--)
   {
-    for (int i = 0; i < m_Pos; i++)
-      m_Value ^= ((UInt32)(m_Hist[i])) << (8 * (m_Pos - i - 1));
+    sum ^= GetUi32(p);
+    p += 4;
   }
-  void UpdateUInt32(UInt32 v) { m_Value ^= v; }
-  UInt32 GetResult() const {  return m_Value; }
-};
-
-void CCheckSum2::Update(const void *data, UInt32 size)
-{
-  UInt32 checkSum = m_Value;
-  const Byte *dataPointer = (const Byte *)data;
-
-  while (size != 0 && m_Pos != 0)
-  {
-    m_Hist[m_Pos] = *dataPointer++;
-    m_Pos = (m_Pos + 1) & 3;
-    size--;
-    if (m_Pos == 0)
-      for (int i = 0; i < 4; i++)
-        checkSum ^= ((UInt32)m_Hist[i]) << (8 * i);
-  }
-
-  int numWords = size / 4;
-  
-  while (numWords-- != 0)
-  {
-    UInt32 temp = *dataPointer++;
-    temp |= ((UInt32)(*dataPointer++)) <<  8;
-    temp |= ((UInt32)(*dataPointer++)) << 16;
-    temp |= ((UInt32)(*dataPointer++)) << 24;
-    checkSum ^= temp;
-  }
-  m_Value = checkSum;
-
   size &= 3;
-  
-  while (size != 0)
-  {
-    m_Hist[m_Pos] = *dataPointer++;
-    m_Pos = (m_Pos + 1) & 3;
-    size--;
-  }
+  if (size > 2) sum ^= (UInt32)(*p++) << 16;
+  if (size > 1) sum ^= (UInt32)(*p++) << 8;
+  if (size > 0) sum ^= (UInt32)(*p++);
+  return sum;
 }
 
-static const UInt32 kDataBlockHeaderSize = 8;
-
-class CTempCabInBuffer2
+HRESULT CCabBlockInStream::PreRead(ISequentialInStream *stream, UInt32 &packSize, UInt32 &unpackSize)
 {
-public:
-  Byte Buffer[kDataBlockHeaderSize];
-  UInt32 Pos;
-  Byte ReadByte()
-  {
-    return Buffer[Pos++];
-  }
-  UInt32 ReadUInt32()
-  {
-    UInt32 value = 0;
-    for (int i = 0; i < 4; i++)
-      value |= (((UInt32)ReadByte()) << (8 * i));
-    return value;
-  }
-  UInt16 ReadUInt16()
-  {
-    UInt16 value = 0;
-    for (int i = 0; i < 2; i++)
-      value |= (((UInt16)ReadByte()) << (8 * i));
-    return value;
-  }
-};
-
-HRESULT CCabBlockInStream::PreRead(UInt32 &packSize, UInt32 &unpackSize)
-{
-  CTempCabInBuffer2 inBuffer;
-  inBuffer.Pos = 0;
-  RINOK(ReadStream_FALSE(_stream, inBuffer.Buffer, kDataBlockHeaderSize))
-
-  UInt32 checkSum = inBuffer.ReadUInt32();
-  packSize = inBuffer.ReadUInt16();
-  unpackSize = inBuffer.ReadUInt16();
-  if (ReservedSize != 0)
-  {
-    RINOK(ReadStream_FALSE(_stream, _buffer, ReservedSize));
-  }
-  _pos = 0;
-  CCheckSum2 checkSumCalc;
-  checkSumCalc.Init();
-  UInt32 packSize2 = packSize;
-  if (MsZip && _size == 0)
-  {
-    if (packSize < 2)
-      return S_FALSE; // bad block;
-    Byte sig[2];
-    RINOK(ReadStream_FALSE(_stream, sig, 2));
-    if (sig[0] != 0x43 || sig[1] != 0x4B)
-      return S_FALSE;
-    packSize2 -= 2;
-    checkSumCalc.Update(sig, 2);
-  }
-
-  if (kBlockSize - _size < packSize2)
+  const UInt32 kHeaderSize = 8;
+  const UInt32 kReservedMax = 256;
+  Byte header[kHeaderSize + kReservedMax];
+  RINOK(ReadStream_FALSE(stream, header, kHeaderSize + ReservedSize))
+  packSize = GetUi16(header + 4);
+  unpackSize = GetUi16(header + 6);
+  if (packSize > kBlockSize - _size)
     return S_FALSE;
-
-  UInt32 curSize = packSize2;
-  if (curSize != 0)
+  RINOK(ReadStream_FALSE(stream, _buf + _size, packSize));
+  
+  if (MsZip)
   {
-    size_t processedSizeLoc = curSize;
-    RINOK(ReadStream(_stream, _buffer + _size, &processedSizeLoc));
-    checkSumCalc.Update(_buffer + _size, (UInt32)processedSizeLoc);
-    _size += (UInt32)processedSizeLoc;
-    if (processedSizeLoc != curSize)
+    if (_size == 0)
+    {
+      if (packSize < 2 || _buf[0] != 0x43 || _buf[1] != 0x4B)
+        return S_FALSE;
+      _pos = 2;
+    }
+    if (_size + packSize > ((UInt32)1 << 15) + 12) /* v9.31 fix. MSZIP specification */
       return S_FALSE;
   }
-  TotalPackSize = _size;
 
-  checkSumCalc.FinishDataUpdate();
-  
-  bool dataError;
-  if (checkSum == 0)
-    dataError = false;
-  else
-  {
-    checkSumCalc.UpdateUInt32(packSize | (((UInt32)unpackSize) << 16));
-    dataError = (checkSumCalc.GetResult() != checkSum);
-  }
-  DataError |= dataError;
-  return dataError ? S_FALSE : S_OK;
+  if (GetUi32(header) != 0) // checkSum
+    if (CheckSum(header, kHeaderSize + ReservedSize) != CheckSum(_buf + _size, packSize))
+      return S_FALSE;
+
+  _size += packSize;
+  return S_OK;
 }
 
 STDMETHODIMP CCabBlockInStream::Read(void *data, UInt32 size, UInt32 *processedSize)
 {
-  if (processedSize != 0)
-    *processedSize = 0;
-  if (size == 0)
-    return S_OK;
-  if (_size != 0)
-  {
-    size = MyMin(_size, size);
-    memmove(data, _buffer + _pos, size);
-    _pos += size;
-    _size -= size;
-    if (processedSize != 0)
-      *processedSize = size;
-    return S_OK;
-  }
-  return S_OK; // no blocks data
+  UInt32 rem = _size - _pos;
+  if (size > rem)
+    size = rem;
+  memcpy(data, _buf + _pos, size);
+  _pos += size;
+  if (processedSize)
+    *processedSize = size;
+  return S_OK;
 }
 
 }}