InBuffer.cpp revision baa3858d3f5d128a5c8466b700098109edcad5f2 
1// InBuffer.cpp
2
3#include "StdAfx.h"
4
5#include "../../../C/Alloc.h"
6
7#include "InBuffer.h"
8
9CInBuffer::CInBuffer():
10  _buffer(0),
11  _bufferLimit(0),
12  _bufferBase(0),
13  _stream(0),
14  _bufferSize(0)
15{}
16
17bool CInBuffer::Create(UInt32 bufferSize)
18{
19  const UInt32 kMinBlockSize = 1;
20  if (bufferSize < kMinBlockSize)
21    bufferSize = kMinBlockSize;
22  if (_bufferBase != 0 && _bufferSize == bufferSize)
23    return true;
24  Free();
25  _bufferSize = bufferSize;
26  _bufferBase = (Byte *)::MidAlloc(bufferSize);
27  return (_bufferBase != 0);
28}
29
30void CInBuffer::Free()
31{
32  ::MidFree(_bufferBase);
33  _bufferBase = 0;
34}
35
36void CInBuffer::SetStream(ISequentialInStream *stream)
37{
38  _stream = stream;
39}
40
41void CInBuffer::Init()
42{
43  _processedSize = 0;
44  _buffer = _bufferBase;
45  _bufferLimit = _buffer;
46  _wasFinished = false;
47  #ifdef _NO_EXCEPTIONS
48  ErrorCode = S_OK;
49  #endif
50}
51
52bool CInBuffer::ReadBlock()
53{
54  #ifdef _NO_EXCEPTIONS
55  if (ErrorCode != S_OK)
56    return false;
57  #endif
58  if (_wasFinished)
59    return false;
60  _processedSize += (_buffer - _bufferBase);
61  UInt32 numProcessedBytes;
62  HRESULT result = _stream->Read(_bufferBase, _bufferSize, &numProcessedBytes);
63  #ifdef _NO_EXCEPTIONS
64  ErrorCode = result;
65  #else
66  if (result != S_OK)
67    throw CInBufferException(result);
68  #endif
69  _buffer = _bufferBase;
70  _bufferLimit = _buffer + numProcessedBytes;
71  _wasFinished = (numProcessedBytes == 0);
72  return (!_wasFinished);
73}
74
75Byte CInBuffer::ReadBlock2()
76{
77  if (!ReadBlock())
78  {
79    _processedSize++;
80    return 0xFF;
81  }
82  return *_buffer++;
83}
84