MSTableIndex.h

Go to the documentation of this file.

// # MSTableIndex: index into a MeasurementSet sub-table
// # Copyright (C) 2000,2001,2002
// # 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 MS_MSTABLEINDEX_H
#define MS_MSTABLEINDEX_H
 
#include <casacore/casa/aips.h>
#include <casacore/casa/Arrays/Vector.h>
#include <casacore/casa/Containers/Block.h>
#include <casacore/casa/Containers/RecordField.h>
#include <casacore/tables/Tables/Table.h>
#include <casacore/tables/Tables/ScalarColumn.h>
#include <casacore/tables/Tables/ColumnsIndex.h>
 
namespace casacore {  // # NAMESPACE CASACORE - BEGIN
 
// # Forward declarations
class Record;
// class ColumnsIndex;
class String;
 
// <summary>
// </summary>
 
// <use visibility=export>
 
// <reviewed reviewer="" date="yyyy/mm/dd" tests="" demos="">
// </reviewed>
 
// <prerequisite>
//   <li> MeasurementSet
//   <li> ColumnsIndex
// </prerequisite>
//
// <etymology>
// </etymology>
//
// <synopsis>
// </synopsis>
//
// <example>
// </example>
//
// <motivation>
// </motivation>
//
// <thrown>
//    <li>
//    <li>
// </thrown>
//
// <todo>
//    <li> Make the searches smarter - for TIME sorted tables, if the time to search is
//         past the last seach, there's no need to search any earlier times.
//    <li> Need to handle the INTERVAL=-1 case fully
// </todo>
class MSTableIndex {
 public:
  // no index attached, use the attach function or assignment operator to change that
  MSTableIndex();
 
  // construct one using the indicated subtable which is part of the parent MS
  // using the indicated index columns.  All index columns must be scalar integer
  // columns.  TIME and INTERVAL will be used when present.  A compare function
  // can be provided to over-ride literal matching of column values.
  MSTableIndex(const Table &subTable, const Vector<String> &indexCols,
               ColumnsIndex::Compare *compareFunction = 0);
 
  // construct one from another
  MSTableIndex(const MSTableIndex &other);
 
  virtual ~MSTableIndex();
 
  // assignment operator, refernce semantics
  MSTableIndex &operator=(const MSTableIndex &other);
 
  // attach this to a subtable using indexCols
  void attach(const Table &subTable, const Vector<String> &indexCols,
              ColumnsIndex::Compare *compareFunction = 0);
 
  // Call this when an index in an existing row has changed.  There is no need to
  // call this when new rows are added to the table
  virtual void setChanged();
 
  // access the record of index (integer) keys
  virtual Record &accessKey() { return *key_p; }
 
  // access the TIME to use in the search (seconds)
  virtual Double &time() { return time_p; }
 
  // access the INTERVAL to use in the search (seconds), must be >= 0
  virtual Double &interval() { return interval_p; }
 
  // get all of the rows in the subTable which have data during the indicated time and
  // interval values.  For now, this code will miss the case where the subtable has
  // interval = -1 and the start time is outside of the time range implied by the time
  // and interval.  If the table has changed and the time is >
  virtual RowNumbers getRowNumbers();
 
  // get the row number which falls in the interval and has the time nearest to the
  // center of the interval (time()).  This also has the same problem as the previous function.
  virtual Int64 getNearestRow(Bool &found);
 
  // is this attached to a null table
  virtual Bool isNull() { return tab_p.isNull(); }
 
  // return the subtable being indexed
  virtual Table &table() { return tab_p; }
 
 private:
  // the subtable
  Table tab_p;
 
  ScalarColumn<Double> timeColumn_p, intervalColumn_p;
  Vector<Double> timeVec_p, intervalVec_p;
  const Double *timeVals_p, *intervalVals_p;
  Bool deleteItTime_p, deleteItInterval_p;
 
  // Internal keys - set by user
  Record *key_p;
  Block<RecordFieldPtr<Int>> intKeys_p;
  Double time_p, interval_p;
 
  // last known integer key values
  Vector<Int> lastKeys_p;
  // last known time and interval
  Double lastTime_p, lastInterval_p;
 
  // last search result - matching integer keys
  RowNumbers lastSearch_p;
 
  // last nearest
  Int64 lastNearest_p;
  Bool nearestFound_p, nearestReady_p;
 
  // last known sub-table size
  rownr_t nrows_p;
 
  Bool hasChanged_p;
 
  ColumnsIndex *index_p;
  Block<RecordFieldPtr<Int>> indexKeys_p;
  Bool hasTime_p, hasInterval_p;
 
  void clear();
  void makeKeys();
  Bool keysChanged();
  void getInternals();
  void nearestTime();
};
 
}  // namespace casacore
 
#endif