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IncrStManAccessor.h
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//# IncrStManAccessor.h: Gives access to some IncrementalStMan functions
//# Copyright (C) 1996,1999,2000,2001
//# 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_INCRSTMANACCESSOR_H
#define TABLES_INCRSTMANACCESSOR_H
//# Includes
#include <casacore/casa/aips.h>
#include <casacore/tables/DataMan/DataManAccessor.h>
#include <casacore/casa/iosfwd.h>
namespace casacore { //# NAMESPACE CASACORE - BEGIN
//# Forward Declarations
class ISMBase;
class DataManager;
class Table;
class String;
// <summary>
// Give access to some IncrementalStMan functions
// </summary>
// <use visibility=export>
// <reviewed reviewer="UNKNOWN" date="before2004/08/25" tests="" demos="">
// </reviewed>
// <prerequisite>
//# Classes you should understand before using this one.
// <li> <linkto class=IncrementalStMan>IncrementalStMan</linkto>
// </prerequisite>
// <synopsis>
// The Table system has one or more storage managers underneath.
// One of these possible storage managers is the
// <linkto class=IncrementalStMan>IncrementalStMan</linkto>.
// This storage manager uses a cache of buckets. The default
// cache size is defined when the IncrementalStMan object was
// constructed at the time the table was created.
// <p>
// Sometimes it can be useful to change the cache size. E.g. when
// the table is accessed in a random way, the hit rate may drop
// when the cache is too small. The class ROIncrStManAccessor makes
// it possible to change the cache size in a temporary way.
// <br>
// Furthermore this class makes it possible to show the cache size
// and to show the cache statistics.
// <motivation>
// In principle a pointer to IncrementalStMan could be used.
// However, that would give access to all public functions.
// Furthermore it could not distinguish between read/write and readonly
// tables.
// </motivation>
// <example>
// This example shows how to set the cache size for
// the incremental storage manager with the name "ISMExample". The cache
// size is not persistent, i.e. when the same table is reopened
// at a later time, this cache size is not remembered.
// <srcblock>
// // Open a table.
// Table table("someName.data");
// // Set the cache size of its incremental storage manager ISMExample
// // to 5 buckets.
// ROIncrementalStManAccessor accessor(table, "ISMExample");
// accessor.setCacheSize (5);
// </srcblock>
// </example>
//# <todo asof="$DATE:$">
//# </todo>
class ROIncrementalStManAccessor : public RODataManAccessor
{
public:
// Construct the object for a data manager in the table given the name
// of the data manager or the column.
// An exception is thrown if the data manager type is not the incremental
// storage manager.
ROIncrementalStManAccessor (const Table& table, const String& name,
Bool byColumn=False);
virtual ~ROIncrementalStManAccessor();
// Copy constructor (reference semantics).
ROIncrementalStManAccessor (const ROIncrementalStManAccessor& that);
// Assignment (reference semantics).
ROIncrementalStManAccessor& operator=
(const ROIncrementalStManAccessor& that);
// Set the cache size (in buckets) to be used by the
// storage manager.
// The cache size given in this way is not persistent.
// Only the cache size given to the constructors of the incremental
// storage managers, is persistent.
// If <src>canExceedNrBuckets=True</src>, the given cache size can be
// larger than the nr of buckets in the file. In this way the cache can
// be made large enough for a future file extnsion.
// Otherwise, it is limited to the actual number of buckets. This is useful
// if one wants the entire file to be cached.
void setCacheSize (uInt aSize, Bool canExceedNrBuckets=True);
// Get the cache size (in buckets).
uInt cacheSize() const;
// Clear the caches used by the hypercubes in this storage manager.
// It will flush the caches as needed and remove all buckets from them
// resulting in a possibly large drop in memory used.
void clearCache();
// Show the index used by this storage manager.
void showIndexStatistics (ostream& os) const;
// Show the layout of the buckets used by this storage manager.
void showBucketLayout (ostream& os) const;
// Check that there are no repeated rowIds in the buckets comprising this ISM
Bool checkBucketLayout (uInt& offendingCursor,
rownr_t& offendingBucketStartRow,
uInt& offendingBucketNrow,
uInt& offendingBucketNr,
uInt& offendingCol,
uInt& offendingIndex,
rownr_t& offendingRow,
rownr_t& offendingPrevRow) const;
private:
//# Declare the data members.
ISMBase* dataManPtr_p;
};
} //# NAMESPACE CASACORE - END
#endif
casacore::DataManager
Abstract base class for a data manager.
Definition DataManager.h:219
casacore::ISMBase
Definition ISMBase.h:86
casacore::RODataManAccessor::RODataManAccessor
RODataManAccessor()
Construct an empty object.
Definition DataManAccessor.h:79
casacore::ROIncrementalStManAccessor::setCacheSize
void setCacheSize(uInt aSize, Bool canExceedNrBuckets=True)
Set the cache size (in buckets) to be used by the storage manager.
casacore::ROIncrementalStManAccessor::~ROIncrementalStManAccessor
virtual ~ROIncrementalStManAccessor()
casacore::ROIncrementalStManAccessor::clearCache
void clearCache()
Clear the caches used by the hypercubes in this storage manager.
casacore::ROIncrementalStManAccessor::ROIncrementalStManAccessor
ROIncrementalStManAccessor(const ROIncrementalStManAccessor &that)
Copy constructor (reference semantics).
casacore::ROIncrementalStManAccessor::showIndexStatistics
void showIndexStatistics(ostream &os) const
Show the index used by this storage manager.
casacore::ROIncrementalStManAccessor::dataManPtr_p
ISMBase * dataManPtr_p
Definition IncrStManAccessor.h:156
casacore::ROIncrementalStManAccessor::cacheSize
uInt cacheSize() const
Get the cache size (in buckets).
casacore::ROIncrementalStManAccessor::ROIncrementalStManAccessor
ROIncrementalStManAccessor(const Table &table, const String &name, Bool byColumn=False)
Construct the object for a data manager in the table given the name of the data manager or the column...
casacore::ROIncrementalStManAccessor::showBucketLayout
void showBucketLayout(ostream &os) const
Show the layout of the buckets used by this storage manager.
casacore::ROIncrementalStManAccessor::checkBucketLayout
Bool checkBucketLayout(uInt &offendingCursor, rownr_t &offendingBucketStartRow, uInt &offendingBucketNrow, uInt &offendingBucketNr, uInt &offendingCol, uInt &offendingIndex, rownr_t &offendingRow, rownr_t &offendingPrevRow) const
Check that there are no repeated rowIds in the buckets comprising this ISM.
casacore::String
String: the storage and methods of handling collections of characters.
Definition String.h:223
casacore::Table
Definition Table.h:157
casacore
this file contains all the compiler specific defines
Definition mainpage.dox:28
casacore::False
const Bool False
Definition aipstype.h:42
casacore::uInt
unsigned int uInt
Definition aipstype.h:49
casacore::name
String name() const
Return the name of the field.
Definition RecordField.h:163
casacore::Bool
bool Bool
Define the standard types used by Casacore.
Definition aipstype.h:40
casacore::True
const Bool True
Definition aipstype.h:41
casacore::rownr_t
uInt64 rownr_t
Define the type of a row number in a table.
Definition aipsxtype.h:44