RRawFileDavix.hxx

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// @(#)root/io:$Id$
// Author: Jakob Blomer
 
/*************************************************************************
 * Copyright (C) 1995-2018, 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_RRawFileDavix
#define ROOT_RRawFileDavix
 
#include <ROOT/RRawFile.hxx>
#include <ROOT/RStringView.hxx>
 
#include <cstddef>
#include <cstdint>
#include <memory>
 
namespace ROOT {
namespace Internal {
 
struct RDavixFileDes;
 
/** \class RRawFileDavix RRawFileDavix.hxx
 
The RRawFileDavix class provides read-only access to remote non-ROOT files.  It uses the Davix library for
the transport layer.  It instructs the RRawFile base class to buffer in larger chunks than the default for
local files, assuming that remote file access has high(er) latency.
 
*/
 
class RRawFileDavix : public RRawFile {
private:
   std::unique_ptr<Internal::RDavixFileDes> fFileDes;
 
protected:
   void OpenImpl() final;
   size_t ReadAtImpl(void *buffer, size_t nbytes, std::uint64_t offset) final;
   void ReadVImpl(RIOVec *ioVec, unsigned int nReq) final;
   std::uint64_t GetSizeImpl() final;
 
public:
   RRawFileDavix(std::string_view url, RRawFile::ROptions options);
   ~RRawFileDavix();
   std::unique_ptr<RRawFile> Clone() const final;
   int GetFeatures() const final { return kFeatureHasSize; }
};
 
} // namespace Internal
} // namespace ROOT
 
#endif