www.pudn.com > NeroSDK-v1.05.zip > FileHelper.cpp

/****************************************************************************** 
|* THIS CODE AND INFORMATION IS PROVIDED "AS IS" WITHOUT WARRANTY OF 
|* ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO 
|* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND/OR FITNESS FOR A 
|* PARTICULAR PURPOSE. 
|*  
|* Copyright 1995-2004 Ahead Software AG. All Rights Reserved. 
|*----------------------------------------------------------------------------- 
|* PROJECT: Nero Plugin Manager Example 
|* 
|* FILE: FileHelper.cpp 
|* 
|* PURPOSE: Implementation of helper functions for file access 
******************************************************************************/ 
 
#include "stdafx.h" 
 
#include "FileHelper.h" 
 
#ifdef _DEBUG 
# define new DEBUG_NEW 
#undef THIS_FILE 
static char THIS_FILE[] = __FILE__; 
#endif 
 
 
// Returns the current position in the file. 
 
DWORD GetFilePointer(HANDLE hFile) 
{ 
  ASSERT(hFile != INVALID_HANDLE_VALUE); 
 
  return SetFilePointer(hFile, 0, 0, FILE_CURRENT); 
} 
 
 
// Reads a DWORD from a file, if it's not possible throws an exception. This 
// allows to scan the file with multiple read without checking after every read. 
 
void ReadDWORD(void* pObject, HANDLE hFile) 
{ 
  if(!(pObject && hFile)) 
  { 
    ASSERT(FALSE); 
 
    throw FALSE; 
  } 
 
  DWORD dwRead = 0; 
 
  if (!(ReadFile(hFile, pObject, sizeof(DWORD), &dwRead, NULL) && 
    dwRead == sizeof(DWORD))) 
  { 
    throw FALSE; 
  } 
} 
 
 
// Reads a WORD from a file, if it's not possible throws an exception. This 
// allows to scan the file with multiple read without checking after every read. 
 
void ReadWORD(void* pObject, HANDLE hFile) 
{ 
  if(!(pObject && hFile)) 
  { 
    ASSERT(FALSE); 
 
    throw FALSE; 
  } 
 
  DWORD dwRead = 0; 
 
  if (!(ReadFile(hFile, pObject, sizeof(WORD), &dwRead, NULL) && 
    dwRead == sizeof(WORD))) 
  { 
    throw FALSE; 
  } 
} 
 
 
// Reads a DWORD from the file and aligns it to a 2-byte border since the chunk 
// length must be aligned to word size. 
 
DWORD ReadChunkLen(HANDLE hFile) 
{ 
  ASSERT(hFile); 
 
  DWORD dwLen = 0; 
 
  ReadDWORD(&dwLen, hFile); 
 
  if (dwLen % 2) 
  { 
    dwLen++; 
  } 
 
  return dwLen; 
} 
 
 
// Writes a byte in the file. 
 
void WriteZeroByte(HANDLE hFile) 
{ 
  if(hFile) 
  { 
    BYTE  bt      = 0; 
    DWORD dwWritten = 0; 
 
    WriteFile(hFile, &bt, 1, &dwWritten, NULL); 
  } 
  else 
  { 
    ASSERT(FALSE); 
  } 
}