largeFileFunctions.h

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/******************************************************************************
** Copyright (c) 1992-2010 VT MAK
** All rights reserved.
******************************************************************************/


#ifndef largeFileFunctions_H_
#define largeFileFunctions_H_

#include "lgrUtil.h"

#include <stddef.h>
#include <vlutil/vlMachineTypes.h>

class DtFilename;

namespace MAKLogger
{
   typedef int DtFileDesc;

   class DT_DLL_LGRUTIL DtLargeFileFunctions
   {
   public:

      static DtFileDesc openForReading(const DtFilename& filename, bool randomAccess /*= true*/);

      static DtFileDesc openForWriting(const DtFilename& filename,  bool truncate = true);

      static DtFileDesc openForReadingAndWriting(DtFilename filename,
         bool truncate = false, bool randomAccess = true);

      static bool close(DtFileDesc);

      static DtInt64 size(DtFileDesc);

      static DtInt64 tell(DtFileDesc);

      static DtInt64 seekCurrent(DtFileDesc,DtInt64);

      static DtInt64 seekEnd(DtFileDesc,DtInt64);

      static DtInt64 seekSet(DtFileDesc,DtInt64);

      static size_t read(DtFileDesc,void* buffer,size_t bytesToRead);

      template <typename T>
      static bool readStruct(DtFileDesc fd,T& structObject)
      {
         size_t desiredSize = sizeof(T);
         size_t readSize = DtLargeFileFunctions::read(fd,&structObject,desiredSize);
         return readSize == desiredSize;
      }

      static char* readBytes(DtFileDesc,size_t bytesToRead,size_t& totalBytesRead);

      static size_t write(DtFileDesc,const void* buffer,size_t bytesToWrite);

      template <typename T>
      static bool writeStruct(DtFileDesc fd,const T& structObject)
      {
         size_t desiredSize = sizeof(T);
         size_t writeSize = DtLargeFileFunctions::write(fd,&structObject,desiredSize);
         return writeSize == desiredSize;
      }

   };

}

#endif