www.pudn.com > RSImageManger.rar > DATASINK.H

/* 
/-------------------------------------------------------------------- 
| 
|      $Id: datasink.h,v 1.5 2000/01/16 20:43:13 anonymous Exp $ 
| 
|      Copyright (c) 1996-1998 Ulrich von Zadow 
| 
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*/ 
// not quite ready for prime-time; bdelmee; 2/99 
 
#ifndef INCL_DATASNK 
#define INCL_DATASNK 
 
#include "except.h" 
 
//! This is a base class for a destination of picture data. 
//! It defines methods to open, write to, close data sinks. 
//! 
//! Restriction: actually writes to a memory buffer that needs 
//! to be foreseen large enough by user (descendant class) 
class CDataSink : public CPLObject 
{ 
  // I'd like to get rid of this, but now it is needed so the encoders 
  // can maintain the actually useful length of the buffer 
  friend class CTIFFEncoder; 
  friend class CTIFFEncoderEx; 
 
public: 
  //! 
  void Open 
    ( const char* pszName, 
      BYTE*   pData, 
      size_t  MaxDataSize 
    ); 
 
  //! 
  virtual void Close 
    (); 
 
  //! 
  char* GetName 
    (); 
 
  //! 
  BYTE* GetBufferPtr 
    (); 
 
  //! 
  size_t GetDataSize 
    (); 
 
  //! 
  size_t GetMaxDataSize 
    (); 
 
  //! 
  size_t WriteNBytes 
    ( size_t   n, 
	  BYTE* pData 
    ); 
 
  //! 
  void Skip 
    ( size_t n ); 
 
  //! Test to see if we didn't go past the "end of the file" 
  void CheckEOF 
    (); 
 
protected: 
  BYTE* m_pStartData; 
  int   m_nCurPos;   // this SHOULD be an unsigned int (size_t), but TIFFLib wants an int 
 
  //! 
  CDataSink 
    (); 
 
  //! 
  virtual ~CDataSink 
   (); 
 
private: 
  char*  m_pszName;    // Name of the data source for diagnostic purposes 
  size_t m_nMaxFileSize; 
}; 
 
 
inline BYTE * CDataSink::GetBufferPtr 
    () 
{ 
	return m_pStartData + m_nCurPos; 
} 
 
inline size_t CDataSink::GetMaxDataSize 
    () 
{ 
  return  m_nMaxFileSize; 
} 
 
inline size_t CDataSink::GetDataSize 
    () 
{ 
  // return currently used buffer size 
  return m_nCurPos; 
} 
 
inline void CDataSink::CheckEOF 
    () 
{ 
  //if (GetFileSize() > GetMaxFileSize()) 
  if (m_nCurPos > (int)m_nMaxFileSize) 
  { 
    throw CTextException (ERR_END_OF_FILE, 
          "Buffer overflow while encoding.\n"); 
  } 
} 
 
inline void CDataSink::Skip 
    ( size_t n ) 
{ 
	// maybe we should fill the gap with nulls 
  m_nCurPos += n; 
  CheckEOF (); 
} 
 
#endif	// INCL_DATASNK 
/* 
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| 
|      $Log: datasink.h,v $ 
|      Revision 1.5  2000/01/16 20:43:13  anonymous 
|      Removed MFC dependencies 
| 
|      Revision 1.4  2000/01/08 15:56:12  Ulrich von Zadow 
|      Made sure change logging works in every file. 
| 
| 
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*/