git.maemo.org Git - physicsfs/blob - lzma/CPP/7zip/Common/InBuffer.cpp

   1 // InBuffer.cpp
   2
   3 #include "StdAfx.h"
   4
   5 #include "InBuffer.h"
   6
   7 extern "C"
   8 {
   9   #include "../../../C/Alloc.h"
  10 }
  11
  12 CInBuffer::CInBuffer():
  13   _buffer(0),
  14   _bufferLimit(0),
  15   _bufferBase(0),
  16   _stream(0),
  17   _bufferSize(0)
  18 {}
  19
  20 bool CInBuffer::Create(UInt32 bufferSize)
  21 {
  22   const UInt32 kMinBlockSize = 1;
  23   if (bufferSize < kMinBlockSize)
  24     bufferSize = kMinBlockSize;
  25   if (_bufferBase != 0 && _bufferSize == bufferSize)
  26     return true;
  27   Free();
  28   _bufferSize = bufferSize;
  29   _bufferBase = (Byte *)::MidAlloc(bufferSize);
  30   return (_bufferBase != 0);
  31 }
  32
  33 void CInBuffer::Free()
  34 {
  35   ::MidFree(_bufferBase);
  36   _bufferBase = 0;
  37 }
  38
  39 void CInBuffer::SetStream(ISequentialInStream *stream)
  40 {
  41   _stream = stream;
  42 }
  43
  44 void CInBuffer::Init()
  45 {
  46   _processedSize = 0;
  47   _buffer = _bufferBase;
  48   _bufferLimit = _buffer;
  49   _wasFinished = false;
  50   #ifdef _NO_EXCEPTIONS
  51   ErrorCode = S_OK;
  52   #endif
  53 }
  54
  55 bool CInBuffer::ReadBlock()
  56 {
  57   #ifdef _NO_EXCEPTIONS
  58   if (ErrorCode != S_OK)
  59     return false;
  60   #endif
  61   if (_wasFinished)
  62     return false;
  63   _processedSize += (_buffer - _bufferBase);
  64   UInt32 numProcessedBytes;
  65   HRESULT result = _stream->Read(_bufferBase, _bufferSize, &numProcessedBytes);
  66   #ifdef _NO_EXCEPTIONS
  67   ErrorCode = result;
  68   #else
  69   if (result != S_OK)
  70     throw CInBufferException(result);
  71   #endif
  72   _buffer = _bufferBase;
  73   _bufferLimit = _buffer + numProcessedBytes;
  74   _wasFinished = (numProcessedBytes == 0);
  75   return (!_wasFinished);
  76 }
  77
  78 Byte CInBuffer::ReadBlock2()
  79 {
  80   if(!ReadBlock())
  81     return 0xFF;
  82   return *_buffer++;
  83 }