casacore::StorageOption Class Reference

Options defining how table files are organized. More...

#include <StorageOption.h>

Public Types
enum	Option {   MultiFile,   MultiHDF5,   SepFile,   Default,   Aipsrc }
	Define the possible options how table files are organized. More...

Public Member Functions
	StorageOption (Option option=Aipsrc, Int blockSize=-2, Int useODirect=-3)
	Create an option object. More...
void	fillOption ()
	Fill the option in case Aipsrc or Default was given. More...
Option	option () const
	Get the option. More...
void	setOption (Option option)
	Set the option. More...
uInt	blockSize () const
	Get the block size (in bytes). More...
void	setBlockSize (Int blockSize)
	Set the block size (in bytes). More...
Bool	useODirect () const
	Get the O_DIRECT option. More...
void	setUseODirect (Bool useODirect)
	Set the O_DIRECT option. More...

Private Attributes
Option	itsOption
Int	itsBlockSize
Bool	itsUseODirect
Bool	itsUseAipsrcODirect

Detailed Description

Options defining how table files are organized.

Intended use:

Public interface

Review Status

Reviewed By:

TPPR

Date Reviewed:

08.11.94

Test programs:

tTable

Synopsis

This class can be used to define how the files of a table are organized. There are two ways:

1. The old way where each storage manager has its own file(s).
2. Using MultiFile that storage managers can use to combine about all table files in a single file. This mode is particularly useful for new file systems (like Lustre) requiring large block sizes.
   The block size to be used in a MultiFile can be defined in this class. Default is 4 MByte.
3. Using MultiHDF5 which behaves similar to MultiFile but uses an HDF5 file instead of a regular file. Note that it requires that support for HDF5 has been used in the build system.

It is possible to specify the storage type and block size using aipsrc. The aipsrc variables are:

• table.storage.option. The (case-insensitive) value can be 'multifile' or 'multihdf5'. Another value means the old way (separate files).
• table.storage.blocksize gives the default blocksize to be used for the multifile and multihdf5 option.
• table.storage.odirect can be true or false. It tells if the O_DIRECT option has to be used to let the kernel bypass its filecache for more predictable I/O behaviour. It's only used for MultiFile and only if the OS supports O_DIRECT.

Definition at line 76 of file StorageOption.h.

Member Enumeration Documentation

enum casacore::StorageOption::Option

Define the possible options how table files are organized.

Enumerator
MultiFile	Let storage managers use a combined MultiFile.
MultiHDF5	Let storage managers use a combined MultiHDF5.
SepFile	Let storage managers use separate files.
Default	Use default (currently SepFile).
Aipsrc	Use as defined in the aipsrc file.

Definition at line 80 of file StorageOption.h.

Constructor & Destructor Documentation

casacore::StorageOption::StorageOption	(	Option	option = Aipsrc,
		Int	blockSize = -2,
		Int	useODirect = -3
	)

Create an option object.

The parameter values are described in the synopsis. The blocksize has to be given in bytes. A size value -2 means reading that size from the aipsrc file. A size value -1 means use the default of 4*1024*1024.
useODirect<0 means reading the option from the aipsrc file. It is only set if the OS supports O_DIRECT.

Member Function Documentation

uInt casacore::StorageOption::blockSize ( ) const

inline

Get the block size (in bytes).

Definition at line 115 of file StorageOption.h.

References itsBlockSize.

Referenced by setBlockSize().

void casacore::StorageOption::fillOption

(

)

Fill the option in case Aipsrc or Default was given.

It is done as explained in the synopsis.

Option casacore::StorageOption::option ( ) const

inline

Get the option.

Definition at line 107 of file StorageOption.h.

References itsOption.

Referenced by setOption().

void casacore::StorageOption::setBlockSize ( Int  blockSize )

inline

Set the block size (in bytes).

Definition at line 119 of file StorageOption.h.

References blockSize(), and itsBlockSize.

void casacore::StorageOption::setOption ( Option  option )

inline

Set the option.

Definition at line 111 of file StorageOption.h.

References itsOption, and option().

void casacore::StorageOption::setUseODirect

(

Bool

useODirect

)

Set the O_DIRECT option.

It is only set if the OS supports O_DIRECT.

Bool casacore::StorageOption::useODirect ( ) const

inline

Get the O_DIRECT option.

Definition at line 123 of file StorageOption.h.

References itsUseODirect.

Member Data Documentation

Int casacore::StorageOption::itsBlockSize

private

Definition at line 132 of file StorageOption.h.

Referenced by blockSize(), and setBlockSize().

Option casacore::StorageOption::itsOption

private

Definition at line 131 of file StorageOption.h.

Referenced by option(), and setOption().

Bool casacore::StorageOption::itsUseAipsrcODirect

private

Definition at line 134 of file StorageOption.h.

Bool casacore::StorageOption::itsUseODirect

private

Definition at line 133 of file StorageOption.h.

Referenced by useODirect().

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The documentation for this class was generated from the following file:

• casa/casacore/tables/Tables/StorageOption.h