TStorageFactoryFile.h

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#ifndef TFILE_ADAPTOR_TSTORAGE_FACTORY_FILE_H
# define TFILE_ADAPTOR_TSTORAGE_FACTORY_FILE_H

# include <vector>
# include <memory>

# include "TFile.h"

# include "Utilities/StorageFactory/interface/IOPosBuffer.h"
#include "FWCore/Utilities/interface/get_underlying_safe.h"


class Storage;

class TStorageFactoryFile : public TFile
{
public:
  ClassDef(TStorageFactoryFile, 0); // ROOT File operating on CMS Storage.

  // Due to limitations in the ROOT plugin manager, TStorageFactoryFile must
  // provide a constructor matching all the different variants that other
  // ROOT plugins might use

  // This one is to match TXNetFile
  TStorageFactoryFile(const char *name, Option_t *option,
                      const char *ftitle, Int_t compress, Int_t netopt,
                      Bool_t parallelopen = kFALSE);

  // This matches everything else.
  TStorageFactoryFile(const char *name, Option_t *option = "",
                      const char *ftitle = "", Int_t compress = 1);

  ~TStorageFactoryFile(void);

  virtual Bool_t    ReadBuffer(char *buf, Int_t len);
  virtual Bool_t    ReadBuffer(char *buf, Long64_t pos, Int_t len);
  virtual Bool_t    ReadBufferAsync(Long64_t off, Int_t len);
  virtual Bool_t    ReadBuffers(char *buf,  Long64_t *pos, Int_t *len, Int_t nbuf);
  virtual Bool_t    WriteBuffer(const char *buf, Int_t len);

  void          ResetErrno(void) const;

protected:
  virtual Int_t     SysOpen(const char *pathname, Int_t flags, UInt_t mode);
  virtual Int_t     SysClose(Int_t fd);
  virtual Long64_t  SysSeek(Int_t fd, Long64_t offset, Int_t whence);
  virtual Int_t     SysStat(Int_t fd, Long_t *id, Long64_t *size, Long_t *flags, Long_t *modtime);
  virtual Int_t     SysSync(Int_t fd);

private:
  void                  Initialize(const char *name, Option_t *option = "");

  Bool_t                ReadBuffersSync(char *buf, Long64_t *pos, Int_t *len, Int_t nbuf);

  void                  releaseStorage() {get_underlying_safe(storage_).release();}

  TStorageFactoryFile(void);

  edm::propagate_const<std::unique_ptr<Storage>> storage_; //< Real underlying storage
};

#endif // TFILE_ADAPTOR_TSTORAGE_FACTORY_FILE_H