TSMFile.h

Go to the documentation of this file.

// # TSMFile.h: File object for Tiled Storage Manager
// # Copyright (C) 1995,1996,1997,1999,2001
// # Associated Universities, Inc. Washington DC, USA.
// #
// # This library is free software; you can redistribute it and/or modify it
// # under the terms of the GNU Library General Public License as published by
// # the Free Software Foundation; either version 2 of the License, or (at your
// # option) any later version.
// #
// # This library is distributed in the hope that it will be useful, but WITHOUT
// # ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
// # FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Library General Public
// # License for more details.
// #
// # You should have received a copy of the GNU Library General Public License
// # along with this library; if not, write to the Free Software Foundation,
// # Inc., 675 Massachusetts Ave, Cambridge, MA 02139, USA.
// #
// # Correspondence concerning AIPS++ should be addressed as follows:
// #        Internet email: casa-feedback@nrao.edu.
// #        Postal address: AIPS++ Project Office
// #                        National Radio Astronomy Observatory
// #                        520 Edgemont Road
// #                        Charlottesville, VA 22903-2475 USA
 
#ifndef TABLES_TSMFILE_H
#define TABLES_TSMFILE_H
 
// # Includes
#include <casacore/casa/aips.h>
#include <casacore/casa/IO/BucketFile.h>
 
namespace casacore {  // # NAMESPACE CASACORE - BEGIN
 
// # Forward Declarations
class TSMOption;
class TiledStMan;
class MultiFileBase;
class AipsIO;
 
// <summary>
// File object for Tiled Storage Manager.
// </summary>
 
// <use visibility=local>
 
// <reviewed reviewer="UNKNOWN" date="before2004/08/25" tests="">
// </reviewed>
 
// <prerequisite>
// # Classes you should understand before using this one.
//   <li> <linkto class=TiledStMan>TiledStMan</linkto>
// </prerequisite>
 
// <etymology>
// TSMFile represents a data file for the Tiled Storage Manager.
// </etymology>
 
// <synopsis>
// A TSMFile object represents a data file. Currently it is meant
// for the TiledStMan classes, but it can easily be turned into
// a more general storage manager file class.
// <br>
// Creation of a TSMFile object does not open the file.
// An explicit open call has to be given before the file can be used.
// <p>
// Underneath it uses a BucketFile to access the file.
// In this way the IO details are well encapsulated.
// </synopsis>
 
// <motivation>
// Encapsulate the Tiled Storage Manager file details.
// </motivation>
 
// # <todo asof="$DATE:$">
// # </todo>
 
class TSMFile {
 public:
  // Create a TSMFile object (with corresponding file).
  // The sequence number gets part of the file name.
  TSMFile(const TiledStMan* stMan, uInt fileSequenceNr, const TSMOption&,
          const std::shared_ptr<MultiFileBase>& = std::shared_ptr<MultiFileBase>());
 
  // Create a TSMFile object for the given existing file.
  TSMFile(const String& fileName, Bool writable, const TSMOption&,
          const std::shared_ptr<MultiFileBase>& = std::shared_ptr<MultiFileBase>());
 
  // Read the object back.
  // The file is not opened until the first access,
  // thus until the file descriptor is asked for the first time.
  // It checks if the sequence number matches the expected one.
  TSMFile(const TiledStMan* stMan, AipsIO& ios, uInt seqnr, const TSMOption&,
          const std::shared_ptr<MultiFileBase>& = std::shared_ptr<MultiFileBase>());
 
  // The destructor closes the file.
  ~TSMFile();
 
  // Forbid copy constructor.
  TSMFile(const TSMFile&) = delete;
 
  // Forbid assignment.
  TSMFile& operator=(const TSMFile&) = delete;
 
  // Write the object.
  void putObject(AipsIO& ios) const;
 
  // Get the object.
  void getObject(AipsIO& ios);
 
  // Open the file if not open yet.
  void open();
 
  // Return the BucketFile object (to be used in the BucketCache).
  BucketFile* bucketFile();
 
  // Return the logical file length.
  Int64 length() const;
 
  // Return the file sequence number.
  uInt sequenceNumber() const;
 
  // Increment the logical file length.
  void extend(Int64 increment);
 
 private:
  // The file sequence number.
  uInt fileSeqnr_p;
  // The file object.
  BucketFile* file_p;
  // The (logical) length of the file.
  Int64 length_p;
};
 
inline Int64 TSMFile::length() const { return length_p; }
 
inline uInt TSMFile::sequenceNumber() const { return fileSeqnr_p; }
 
inline void TSMFile::extend(Int64 increment) { length_p += increment; }
 
inline BucketFile* TSMFile::bucketFile() { return file_p; }
 
inline void TSMFile::open() { file_p->open(); }
 
}  // namespace casacore
 
#endif