TableRecordRep.h

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// # TableRecordRep.h: The representation of a TableRecord
// # Copyright (C) 1996,1997,2000,2001
// # 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_TABLERECORDREP_H
#define TABLES_TABLERECORDREP_H
 
#include <casacore/casa/aips.h>
#include <casacore/casa/Containers/RecordRep.h>
 
namespace casacore {  // # NAMESPACE CASACORE - BEGIN
 
// # Forward Declarations
class TableRecord;
class TableAttr;
 
// <summary>
// The representation of a TableRecord
// </summary>
 
// <use visibility=local>
// <reviewed reviewer="Mark Wieringa" date="1996/04/15" tests="tTableRecord">
// </reviewed>
 
// <prerequisite>
//   <li> <linkto class="TableRecord">TableRecord</linkto>.
//   <li> <linkto class="RecordRep">RecordRep</linkto>.
// </prerequisite>
//
// <etymology>
// TableRecordRep is the REPresentation of a TableRecord.
// </etymology>
//
// <synopsis>
// TableRecordRep is the actual implementation of a TableRecord object.
// It contains the description and the data. The data is stored as
// a collection of void* pointers to the actual data. By storing
// it in this indirect way, it is easier to extend the data block.
// It also means that RecordFieldPtr objects always have the correct
// pointer and do not need to be adjusted when the data block is extended.
// <p>
// Despite the fact that the data pointers have type void*, the
// functions are completely type safe. This is done by passing the
// type around using the DataType enumeration. The downpart is that
// only types from that enumeration are supported (but that is also
// required by the RecordDesc mechanics).
// <p>
// Note that TableRecordRep does not know anything about RecordFieldPtr
// objects pointing to its data. Only its mother class TableRecord
// knows about them and handles all cases where the RecordFieldPtr's
// have to be notified.
// <p>
// Fields containing tables are not directly handled using class Table.
// Instead the class <linkto class=TableKeyword>TableKeyword</linkto>
// is used to map a table name to a table and to take care of
// opening a table on demand.
// </synopsis>
//
// <example>
// TableRecordRep mirrors all functions in TableRecord.
// </example>
//
// <motivation>
// Having a separate TableRecordRep class makes copy-on-write possible.
// It also allows derivation from RecordRep.
// </motivation>
//
// # <todo asof="1995/08/22">
// # </todo>
 
class TableRecordRep : public RecordRep {
 public:
  // Create a record with no fields.
  TableRecordRep();
 
  // Create a record with the given description. If it is not possible to
  // create all fields (for example, if a field of an unsupported type is
  // requested), an exception is thrown.
  // All fields are checked by the field checking function (if defined).
  TableRecordRep(const RecordDesc& description);
 
  // Create a copy of other using copy semantics.
  TableRecordRep(const TableRecordRep& other);
 
  // Copy all the data over.
  TableRecordRep& operator=(const TableRecordRep& other);
 
  // Delete all data.
  ~TableRecordRep();
 
  // Get the comment for this field.
  const String& comment(Int whichField) const;
 
  // Set the comment for this field.
  void setComment(Int whichField, const String& comment);
 
  // Describes the current structure of this Record.
  const RecordDesc& description() const;
 
  // Change the structure of this Record to contain the fields in
  // newDescription. After calling restructure, <src>description() ==
  // newDescription</src>.
  void restructure(const RecordDesc& newDescription, Bool recursive);
 
  // Returns True if this and other have the same RecordDesc, other
  // than different names for the fields. That is, the number, type and the
  // order of the fields must be identical (recursively for fixed
  // structured sub-Records in this).
  // <note role=caution>
  // <src>thisRecord.conform(thatRecord) == True</src> does not imply
  // <br><src>thatRecord.conform(thisRecord) == True</src>, because
  // a variable record in one conforms a fixed record in that, but
  // not vice-versa.
  // </note>
  Bool conform(const TableRecordRep& other) const;
 
  // Rename the given field.
  void renameField(const String& newName, Int whichField);
 
  // Copy all data of the TableRecord.
  void copyData(const TableRecordRep& other);
 
  // Add a field with the given name and value to the record.
  // The data type of the field is determined by the data type of the value.
  // <group>
  void addField(const String& name, const TableRecord& value, RecordInterface::RecordType type);
  void addField(const String& name, const Table& value, RecordInterface::RecordType type);
  // </group>
 
  // Define a value for the given field.
  // Array conformance rules will not be applied for variable shaped arrays.
  // When the field and value data type mismatch, type promotion
  // of scalars will be done if possible. If not possible, an exception
  // is thrown.
  void defineDataField(Int whichField, DataType type, const void* value);
 
  // Close the table in the given field.
  // When accessed again, it will be opened automatically.
  // This can be useful to save memory usage.
  void closeTable(Int whichField) const;
 
  // Close all open tables.
  // When accessed again, it will be opened automatically.
  // This can be useful to save memory usage.
  void closeTables() const;
 
  // Flush all open subtables.
  void flushTables(Bool fsync) const;
 
  // Rename the subtables with a path containing the old parent table name.
  void renameTables(const String& newParentName, const String& oldParentName);
 
  // Are subtables used in other processes.
  Bool areTablesMultiUsed() const;
 
  // Put the description and data of the Record.
  // It also puts the fixedFlag attribute (of the mother object).
  void putRecord(AipsIO& os, Int recordType, const TableAttr&) const;
 
  // Get the description and data of the Record.
  // It also gets the fixedFlag attribute (of the mother object).
  void getRecord(AipsIO& os, Int& recordType, const TableAttr&);
 
  // Put the data of a record.
  // This is used to write a subrecord, whose description has
  // already been written.
  void putData(AipsIO& os, const TableAttr&) const;
 
  // Read the data of a record.
  // This is used to read a subrecord, whose description has
  // already been read.
  void getData(AipsIO& os, uInt version, const TableAttr&);
 
  // Reopen possible tables in keywords as read/write.
  // Tables are not reopened if they are not writable.
  void reopenRW();
 
  // Used by the RecordFieldPtr classes to attach in a type-safe way to the
  // correct field.
  // <group>
  void* get_pointer(Int whichField, DataType type) const;
  void* get_pointer(Int whichField, DataType type, const String& recordType) const;
  // </group>
 
  // Merge a field from another record into this record.
  void mergeField(const TableRecordRep& other, Int whichFieldFromOther,
                  RecordInterface::DuplicatesFlag);
 
  // Merge all fields from the other record into this record.
  void merge(const TableRecordRep& other, RecordInterface::DuplicatesFlag);
 
  // Print a record.
  // Print the contents of the record.
  // Only the first <src>maxNrValues</src> of an array will be printed.
  // A value < 0 means the entire array.
  void print(std::ostream&, Int maxNrValues = 25, const String& indent = "") const;
 
 protected:
  // Utility function to avoid code duplication in the public member
  // functions.
  void copy_other(const TableRecordRep& other);
 
  // Get the field number for a given name.
  virtual Int fieldNumber(const String& name) const;
 
  // Add a field to the description.
  virtual void addFieldToDesc(const String& name, DataType type, const IPosition& shape,
                              Bool fixedShape);
 
  // Remove a data field.
  virtual void removeData(Int whichField, void* ptr, void* vecptr);
 
  // Remove a field from the description.
  virtual void removeFieldFromDesc(Int whichField);
 
  // Get a KeywordSet object as a TableRecord.
  // (type: 0=ScalarKeywordSet, 1=ArrayKeywordSet, 2=TableKeywordSet)
  void getTableKeySet(AipsIO& os, uInt version, const TableAttr&, uInt type);
 
  // Holds the description.
  // # Although we could use the RecordDesc object from RecordRep,
  // # it is better to use an own RecordDesc object in case a dedicated
  // # TableRecordDesc is needed in the future. In this way it
  // # is sure that inherited functions do not use the RecordDesc object
  // # in RecordRep.
  RecordDesc desc_p;
};
 
inline const String& TableRecordRep::comment(Int whichField) const {
  return desc_p.comment(whichField);
}
 
inline void TableRecordRep::setComment(Int whichField, const String& comment) {
  desc_p.setComment(whichField, comment);
}
 
inline const RecordDesc& TableRecordRep::description() const { return desc_p; }
 
inline void TableRecordRep::renameField(const String& newName, Int whichField) {
  desc_p.renameField(newName, whichField);
}
 
}  // namespace casacore
 
#endif