RRawFileTFile.hxx

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// Author: Jonas Hahnfeld
 
/*************************************************************************
 * Copyright (C) 1995-2024, Rene Brun and Fons Rademakers.               *
 * All rights reserved.                                                  *
 *                                                                       *
 * For the licensing terms see $ROOTSYS/LICENSE.                         *
 * For the list of contributors see $ROOTSYS/README/CREDITS.             *
 *************************************************************************/
 
#ifndef ROOT_RRawFileTFile
#define ROOT_RRawFileTFile
 
#include <ROOT/RRawFile.hxx>
 
#include <TFile.h>
 
#include <stdexcept>
 
namespace ROOT {
namespace Internal {
 
/**
 * \class RRawFileTFile RRawFileTFile.hxx
 * \ingroup IO
 *
 * The RRawFileTFile wraps an open TFile, but does not take ownership.
 */
class RRawFileTFile : public RRawFile {
private:
   TFile *fFile;
 
protected:
   void OpenImpl() final { fOptions.fBlockSize = 0; }
 
   size_t ReadAtImpl(void *buffer, size_t nbytes, std::uint64_t offset) final
   {
      if (fFile->ReadBuffer(static_cast<char *>(buffer), offset, nbytes)) {
         throw std::runtime_error("failed to read expected number of bytes");
      }
      return nbytes;
   }
 
   std::uint64_t GetSizeImpl() final { return fFile->GetSize(); }
 
public:
   RRawFileTFile(TFile *file) : RRawFile(file->GetEndpointUrl()->GetFile(), {}), fFile(file) {}
 
   std::unique_ptr<ROOT::Internal::RRawFile> Clone() const final { return std::make_unique<RRawFileTFile>(fFile); }
 
   int GetFeatures() const final { return kFeatureHasSize; }
};
 
} // namespace Internal
} // namespace ROOT
 
#endif