Templated virtual column engine to scale a table array. More...

#include <ScaledArrayEngine.h>

Inheritance diagram for casacore::ScaledArrayEngine< VirtualType, StoredType >:

Public Member Functions
	ScaledArrayEngine (const String &virtualColumnName, const String &storedColumnName, VirtualType scale, VirtualType offset=0)
	Construct an engine to scale all arrays in a column with the given offset and scale factor. More...

	ScaledArrayEngine (const String &virtualColumnName, const String &storedColumnName, const String &scaleColumnName, VirtualType offset=0)
	Construct an engine to scale the arrays in a column. More...

	ScaledArrayEngine (const String &virtualColumnName, const String &storedColumnName, const String &scaleColumnName, const String &offsetColumnName)

	ScaledArrayEngine (const Record &spec)
	Construct from a record specification as created by getmanagerSpec(). More...

	~ScaledArrayEngine ()
	Destructor is mandatory. More...

virtual String	dataManagerType () const
	Return the type name of the engine (i.e. More...

virtual String	dataManagerName () const
	Get the name given to the engine (is the virtual column name). More...

virtual Record	dataManagerSpec () const
	Record a record containing data manager specifications. More...

Public Member Functions inherited from casacore::BaseMappedArrayEngine< VirtualType, StoredType >
const String &	virtualName () const
	Get the virtual column name. More...

const String &	storedName () const
	Get the stored column name. More...

virtual Bool	isWritable () const
	The column is writable if the underlying stored column is writable. More...

Public Member Functions inherited from casacore::VirtualColumnEngine
	VirtualColumnEngine ()
	Create the object. More...

virtual	~VirtualColumnEngine ()

Public Member Functions inherited from casacore::DataManager
	DataManager ()
	Default constructor. More...

virtual	~DataManager ()

void	dataManagerInfo (Record &info) const
	Add SEQNR and SPEC (the DataManagerSpec subrecord) to the info. More...

virtual Record	getProperties () const
	Get data manager properties that can be modified. More...

virtual void	setProperties (const Record &spec)
	Modify data manager properties given in record fields. More...

virtual Bool	canReallocateColumns () const
	Tell if the data manager wants to reallocate the data manager column objects. More...

virtual DataManagerColumn *	reallocateColumn (DataManagerColumn *column)
	Reallocate the column object if it is part of this data manager. More...

uInt	sequenceNr () const
	Get the (unique) sequence nr of this data manager. More...

uInt	ncolumn () const
	Get the nr of columns in this data manager (can be zero). More...

Bool	asBigEndian () const
	Have the data to be stored in big or little endian canonical format? More...

const TSMOption &	tsmOption () const
	Get the TSM option. More...

MultiFileBase *	multiFile ()
	Get the MultiFile pointer (can be 0). More...

String	keywordName (const String &keyword) const
	Compose a keyword name from the given keyword appended with the sequence number (e.g. More...

String	fileName () const
	Compose a unique filename from the table name and sequence number. More...

ByteIO::OpenOption	fileOption () const
	Get the AipsIO option of the underlying file. More...

virtual Bool	isRegular () const
	Is this a regular storage manager? It is regular if it allows addition of rows and writing data in them. More...

Table &	table () const
	Get the table this object is associated with. More...

virtual void	reopenRW ()
	Reopen the data manager for read/write access. More...

virtual Bool	canAddColumn () const
	Does the data manager allow to add columns? (default no) More...

virtual Bool	canRemoveColumn () const
	Does the data manager allow to delete columns? (default no) More...

virtual Bool	canRenameColumn () const
	Does the data manager allow to rename columns? (default yes) More...

virtual void	setMaximumCacheSize (uInt nbytes)
	Set the maximum cache size (in bytes) to be used by a storage manager. More...

virtual void	showCacheStatistics (std::ostream &) const
	Show the data manager's IO statistics. More...

DataManagerColumn *	createScalarColumn (const String &columnName, int dataType, const String &dataTypeId)
	Create a column in the data manager on behalf of a table column. More...

DataManagerColumn *	createDirArrColumn (const String &columnName, int dataType, const String &dataTypeId)
	Create a direct array column. More...

DataManagerColumn *	createIndArrColumn (const String &columnName, int dataType, const String &dataTypeId)
	Create an indirect array column. More...

DataManager *	getClone () const
	Has the object already been cloned? More...

void	setClone (DataManager *clone) const
	Set the pointer to the clone. More...

Public Member Functions inherited from casacore::VirtualArrayColumn< VirtualType >
	VirtualArrayColumn ()
	Create a column. More...

virtual	~VirtualArrayColumn ()
	Frees up the storage. More...

virtual int	dataType () const
	Return the data type of the column. More...

virtual String	dataTypeId () const
	Return the data type Id of the column. More...

virtual Bool	canAccessSlice (Bool &reask) const
	The class can handle a get/putSlice. More...

virtual Bool	canAccessArrayColumn (Bool &reask) const
	The class can handle a get/putArrayColumn. More...

virtual Bool	canAccessColumnSlice (Bool &reask) const
	The class can handle a get/putColumnSlice. More...

Public Member Functions inherited from casacore::DataManagerColumn
	DataManagerColumn ()
	Create a column. More...

virtual	~DataManagerColumn ()
	Frees up the storage. More...

void	setIsFixedShape (Bool isFixedShape)
	Set the isFixedShape flag. More...

Bool	isFixedShape () const
	Is this a fixed shape column? More...

virtual void	setMaxLength (uInt maxLength)
	Set the maximum length of the value (can be used for strings). More...

void	setFixedShapeColumn (const IPosition &shape)
	Set the shape of all (fixed-shaped) arrays in the column. More...

virtual void	setShapeTiled (uInt rownr, const IPosition &shape, const IPosition &tileShape)
	Set the shape and tile shape of an (variable-shaped) array in the given row. More...

virtual IPosition	tileShape (uInt rownr)
	Get the tile shape of the item in the given row. More...

virtual Bool	canAccessScalarColumn (Bool &reask) const
	Can the column data manager handle access to a scalar column? If not, the caller should access the column by looping through all cells in the column. More...

virtual Bool	canAccessScalarColumnCells (Bool &reask) const
	Can the column data manager handle access to a clooection of cells in a scalar column? If not, the caller should access the column cells by looping through the cells in the column. More...

virtual Bool	canAccessArrayColumnCells (Bool &reask) const
	Can the column data manager handle access to a collection of cells in an array column? If not, the caller should access the column cells by looping through the cells in the column. More...

ColumnCache &	columnCache ()
	Get access to the ColumnCache object. More...

const ColumnCache *	columnCachePtr () const

void	get (uInt rownr, Bool *dataPtr)
	Get the scalar value in the given row. More...

void	get (uInt rownr, uChar *dataPtr)

void	get (uInt rownr, Short *dataPtr)

void	get (uInt rownr, uShort *dataPtr)

void	get (uInt rownr, Int *dataPtr)

void	get (uInt rownr, uInt *dataPtr)

void	get (uInt rownr, Int64 *dataPtr)

void	get (uInt rownr, float *dataPtr)

void	get (uInt rownr, double *dataPtr)

void	get (uInt rownr, Complex *dataPtr)

void	get (uInt rownr, DComplex *dataPtr)

void	get (uInt rownr, String *dataPtr)

void	get (uInt rownr, void *dataPtr)
	This function is the get for all non-standard data types. More...

void	put (uInt rownr, const Bool *dataPtr)
	Put the scalar value into the given row. More...

void	put (uInt rownr, const uChar *dataPtr)

void	put (uInt rownr, const Short *dataPtr)

void	put (uInt rownr, const uShort *dataPtr)

void	put (uInt rownr, const Int *dataPtr)

void	put (uInt rownr, const uInt *dataPtr)

void	put (uInt rownr, const Int64 *dataPtr)

void	put (uInt rownr, const float *dataPtr)

void	put (uInt rownr, const double *dataPtr)

void	put (uInt rownr, const Complex *dataPtr)

void	put (uInt rownr, const DComplex *dataPtr)

void	put (uInt rownr, const String *dataPtr)

void	put (uInt rownr, const void *dataPtr)
	This function is the put for all non-standard data types. More...

virtual void	getScalarColumnV (void *dataPtr)
	Get all scalar values in the column. More...

virtual void	putScalarColumnV (const void *dataPtr)
	Put all scalar values in the column. More...

virtual void	getScalarColumnCellsV (const RefRows &rownrs, void *dataPtr)
	Get some scalar values in the column. More...

virtual void	putScalarColumnCellsV (const RefRows &rownrs, const void *dataPtr)
	Put some scalar values in the column. More...

virtual uInt	getBlockV (uInt rownr, uInt nrmax, void *dataPtr)
	Get scalars from the given row on with a maximum of nrmax values. More...

virtual void	putBlockV (uInt rownr, uInt nrmax, const void *dataPtr)
	Put nrmax scalars from the given row on. More...

void	throwGet () const
	Throw an "invalid operation" exception for the default implementation of get. More...

void	throwPut () const
	Throw an "invalid operation" exception for the default implementation of put. More...

void	setColumnName (const String &colName)
	Set the column name. More...

const String &	columnName () const
	Get rhe column name. More...

Static Public Member Functions
static String	className ()
	Return the name of the class. More...

static void	registerClass ()
	Register the class name and the static makeObject "constructor". More...

static DataManager *	makeObject (const String &dataManagerType, const Record &spec)

Static Public Member Functions inherited from casacore::DataManager
static void	registerCtor (const String &type, DataManagerCtor func)
	Register a mapping of a data manager type to its static construction function. More...

static DataManagerCtor	getCtor (const String &dataManagerType)
	Get the "constructor" of a data manager (thread-safe). More...

static Bool	isRegistered (const String &dataManagerType)
	Test if a data manager is registered (thread-safe). More...

static DataManager *	unknownDataManager (const String &dataManagerType, const Record &spec)
	Serve as default function for theirRegisterMap, which catches all unknown data manager types. More...

Private Member Functions
	ScaledArrayEngine (const ScaledArrayEngine< VirtualType, StoredType > &)
	Copy constructor is only used by clone(). More...

ScaledArrayEngine< VirtualType, StoredType > &	operator= (const ScaledArrayEngine< VirtualType, StoredType > &)
	Assignment is not needed and therefore forbidden (so it is made private and not implemented). More...

DataManager *	clone () const
	Clone the engine object. More...

void	create (uInt initialNrrow)
	Initialize the object for a new table. More...

void	prepare ()
	Preparing consists of setting the writable switch and adding the initial number of rows in case of create. More...

void	getArray (uInt rownr, Array< VirtualType > &array)
	Get an array in the given row. More...

void	putArray (uInt rownr, const Array< VirtualType > &array)
	Put an array in the given row. More...

void	getSlice (uInt rownr, const Slicer &slicer, Array< VirtualType > &array)
	Get a section of the array in the given row. More...

void	putSlice (uInt rownr, const Slicer &slicer, const Array< VirtualType > &array)
	Put into a section of the array in the given row. More...

void	getArrayColumn (Array< VirtualType > &array)
	Get an entire column. More...

void	putArrayColumn (const Array< VirtualType > &array)
	Put an entire column. More...

void	getColumnSlice (const Slicer &slicer, Array< VirtualType > &array)
	Get a section of all arrays in the column. More...

void	putColumnSlice (const Slicer &slicer, const Array< VirtualType > &array)
	Put a section of all arrays in the column. More...

void	scaleOnGet (VirtualType scale, VirtualType offset, Array< VirtualType > &array, const Array< StoredType > &stored)
	Scale and/or offset stored to array. More...

void	scaleOnPut (VirtualType scale, VirtualType offset, const Array< VirtualType > &array, Array< StoredType > &stored)
	Scale and/or offset array to stored. More...

void	scaleColumnOnGet (Array< VirtualType > &array, const Array< StoredType > &stored)
	Scale and/or offset stored to array for the entire column. More...

void	scaleColumnOnPut (const Array< VirtualType > &array, Array< StoredType > &stored)
	Scale and/or offset array to stored for the entire column. More...

VirtualType	getScale (uInt rownr)
	Get the scale value for this row. More...

VirtualType	getOffset (uInt rownr)
	Get the offset value for this row. More...

Private Attributes
String	scaleName_p

String	offsetName_p

VirtualType	scale_p

VirtualType	offset_p

Bool	fixedScale_p

Bool	fixedOffset_p

ScalarColumn< VirtualType > *	scaleColumn_p

ScalarColumn< VirtualType > *	offsetColumn_p

Additional Inherited Members
Protected Member Functions inherited from casacore::BaseMappedArrayEngine< VirtualType, StoredType >
	BaseMappedArrayEngine (const String &virtualColumnName, const String &storedColumnName)
	Construct an engine to convert the virtual column to the stored column. More...

	~BaseMappedArrayEngine ()
	Destructor is mandatory. More...

	BaseMappedArrayEngine ()
	The default constructor is required for reconstruction of the engine when a table is read back. More...

	BaseMappedArrayEngine (const BaseMappedArrayEngine< VirtualType, StoredType > &)
	Copy constructor is only used by copy constructor of derived classes. More...

void	setWritable (Bool isWritable)
	Set if the column is writable or not. More...

void	setNames (const String &virtualName, const String &storedName)
	Set the virtual and stored column name. More...

ArrayColumn< StoredType > &	column ()
	Give access to the stored column. More...

virtual DataManagerColumn *	makeIndArrColumn (const String &columnName, int dataType, const String &dataTypeId)
	Create the column object for the array column in this engine. More...

void	prepare1 ()
	Do the 2 stages of the prepare (define columns and adding rows). More...

void	prepare2 ()

virtual void	addRow (uInt nrrow)
	Rows are added to the end of the table. More...

virtual void	addRowInit (uInt startRow, uInt nrrow)

virtual void	setShapeColumn (const IPosition &shape)
	Set the shape of the FixedShape arrays in the column. More...

virtual void	setShape (uInt rownr, const IPosition &shape)
	Define the shape of the array in the given row. More...

virtual Bool	isShapeDefined (uInt rownr)
	Test if the (underlying) array is defined in the given row. More...

virtual uInt	ndim (uInt rownr)
	Get the dimensionality of the (underlying) array in the given row. More...

virtual IPosition	shape (uInt rownr)
	Get the shape of the (underlying) array in the given row. More...

virtual Bool	canChangeShape () const
	The data manager can handle changing the shape of an existing array when the underlying stored column can do it. More...

TableColumn	makeTableColumn (const String &columnName)
	Make a table column object for the given column. More...

virtual void	getArrayColumnCells (const RefRows &rownrs, Array< VirtualType > &data)
	Get some array values in the column. More...

virtual void	putArrayColumnCells (const RefRows &rownrs, const Array< VirtualType > &data)
	Put some array values in the column. More...

void	getColumnSlice (const Slicer &slicer, Array< VirtualType > &array)
	Get a section of all arrays in the column. More...

void	putColumnSlice (const Slicer &slicer, const Array< VirtualType > &array)
	Put a section of all arrays in the column. More...

virtual void	getColumnSliceCells (const RefRows &rownrs, const Slicer &slicer, Array< VirtualType > &data)
	Get a section of some arrays in the column. More...

virtual void	putColumnSliceCells (const RefRows &rownrs, const Slicer &slicer, const Array< VirtualType > &data)
	Put into a section of some arrays in the column. More...

virtual IPosition	getStoredShape (uInt rownr, const IPosition &virtualShape)
	Map the virtual shape to the stored shape. More...

virtual Slicer	getStoredSlicer (const Slicer &virtualSlicer) const
	Map the slicer for a virtual shape to a stored shape. More...

virtual void	mapOnGet (Array< VirtualType > &array, const Array< StoredType > &stored)
	Map StoredType array to VirtualType array. More...

virtual void	mapOnPut (const Array< VirtualType > &array, Array< StoredType > &stored)
	Map Bool array to bit flags array. More...

Protected Member Functions inherited from casacore::DataManager
void	decrementNcolumn ()
	Decrement number of columns (in case a column is deleted). More...

void	setEndian (Bool bigEndian)
	Tell the data manager if big or little endian format is needed. More...

void	setTsmOption (const TSMOption &tsmOption)
	Tell the data manager which TSM option to use. More...

void	setMultiFile (MultiFileBase *mfile)
	Tell the data manager that MultiFile can be used. More...

virtual Bool	hasMultiFileSupport () const
	Does the data manager support use of MultiFile? A derived class has to return True if it can use the MultiFile. More...

void	throwDataTypeOther (const String &columnName, int dataType) const
	Throw an exception in case data type is TpOther, because the storage managers (and maybe other data managers) do not support such columns. More...

Protected Member Functions inherited from casacore::DataManagerColumn
virtual void	getBoolV (uInt rownr, Bool *dataPtr)
	Get the scalar value in the given row. More...

virtual void	getuCharV (uInt rownr, uChar *dataPtr)

virtual void	getShortV (uInt rownr, Short *dataPtr)

virtual void	getuShortV (uInt rownr, uShort *dataPtr)

virtual void	getIntV (uInt rownr, Int *dataPtr)

virtual void	getuIntV (uInt rownr, uInt *dataPtr)

virtual void	getInt64V (uInt rownr, Int64 *dataPtr)

virtual void	getfloatV (uInt rownr, float *dataPtr)

virtual void	getdoubleV (uInt rownr, double *dataPtr)

virtual void	getComplexV (uInt rownr, Complex *dataPtr)

virtual void	getDComplexV (uInt rownr, DComplex *dataPtr)

virtual void	getStringV (uInt rownr, String *dataPtr)

virtual void	getOtherV (uInt rownr, void *dataPtr)
	This function is the get for all non-standard data types. More...

virtual void	putBoolV (uInt rownr, const Bool *dataPtr)
	Put the scalar value into the given row. More...

virtual void	putuCharV (uInt rownr, const uChar *dataPtr)

virtual void	putShortV (uInt rownr, const Short *dataPtr)

virtual void	putuShortV (uInt rownr, const uShort *dataPtr)

virtual void	putIntV (uInt rownr, const Int *dataPtr)

virtual void	putuIntV (uInt rownr, const uInt *dataPtr)

virtual void	putInt64V (uInt rownr, const Int64 *dataPtr)

virtual void	putfloatV (uInt rownr, const float *dataPtr)

virtual void	putdoubleV (uInt rownr, const double *dataPtr)

virtual void	putComplexV (uInt rownr, const Complex *dataPtr)

virtual void	putDComplexV (uInt rownr, const DComplex *dataPtr)

virtual void	putStringV (uInt rownr, const String *dataPtr)

virtual void	putOtherV (uInt rownr, const void *dataPtr)
	This function is the put for all non-standard data types. More...

Detailed Description

template<class VirtualType, class StoredType>
class casacore::ScaledArrayEngine< VirtualType, StoredType >

Templated virtual column engine to scale a table array.

Intended use:

Public interface

Review Status

Reviewed By:: Gareth Hunt
Date Reviewed:: 94Nov17

Prerequisite

Synopsis

ScaledArrayEngine is a virtual column engine which scales an array of one type to another type to save disk storage. This resembles the classic AIPS compress method which scales the data from float to short. The scale factor and offset value can be given in two ways:

As a fixed value which is used for all arrays in the column.
As the name of a column. In this way each array in a column can have its own scale and offset value. The scale and offset value in a row must be put before the array is put and should not be changed anymore.

It is also possible to have a variable scale factor with a fixed offset value. As in FITS the scale and offset values are used as:
True_value = Stored_value * scale + offset;

An engine object should be used for one column only, because the stored column name is part of the engine. If it would be used for more than one column, they would all share the same stored column. When the engine is bound to a column, it is checked if the name of that column matches the given virtual column name.

The engine can be used for a column containing any kind of array (thus direct or indirect, fixed or variable shaped)) as long as the virtual array can be stored in the stored array. Thus a fixed shaped virtual can use a variable shaped stored, but not vice versa. A fixed shape indirect virtual can use a stored with direct arrays.

This class can also serve as an example of how to implement a virtual column engine.

Motivation

This class allows to store data in a smaller representation. It is needed to resemble the classic AIPS compress option. It adds the scale and offset value on a per row basis.

Because the engine can serve only one column, it was possible to combine the engine and the column functionality in one class. This has been achieved using multiple inheritance. The advantage of this is that only one templated class is used, so less template instantiations are needed.

Example

// Create the table description and 2 columns with indirect arrays in it.
// The Int column will be stored, while the double will be
// used as virtual.
TableDesc tableDesc ("", TableDesc::Scratch);
tableDesc.addColumn (ArrayColumnDesc<Int> ("storedArray"));
tableDesc.addColumn (ArrayColumnDesc<double> ("virtualArray"));
// Create a new table using the table description.
SetupNewTable newtab (tableDesc, "tab.data", Table::New);
// Create the array scaling engine to scale from double to Int
// and bind it to the double column.
// Create the table.
ScaledArrayEngine<double,Int> scalingEngine("virtualArray",
"storedArray", 10);
newtab.bindColumn ("virtualArray", scalingEngine);
Table table (newtab);
// Store a 3-D array (with dim. 2,3,4) into each row of the column.
// The shape of each array in the column is implicitly set by the put
// function. This will also set the shape of the underlying Int array.
ArrayColumn data (table, "virtualArray");
Array<double> someArray(IPosition(4,2,3,4));
someArray = 0;
for (uInt i=0, i<10; i++) {          // table will have 10 rows
table.addRow();
data.put (i, someArray)
}

Template Type Argument Requirements (VirtualType)

only suited for built-in numerics data types