ObitTableGBTIF.h File Reference

ObitTableGBTIF class definition. More...

#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <glib.h>
#include "Obit.h"
#include "ObitErr.h"
#include "ObitTable.h"

Go to the source code of this file.

Classes
struct	ObitTableGBTIF
	ObitTableGBTIF Class structure. More...
struct	ObitTableGBTIFRow
	ObitTableGBTIFRow Class structure. More...
struct	ObitTableGBTIFClassInfo
	ClassInfo Structure. More...
struct	ObitTableGBTIFRowClassInfo
	ClassInfo Structure For TableObitTableGBTIFRow. More...
Defines
#define	MAXKEYCHARTABLEIF   24
	Number of characters for Table keyword.
#define	ObitTableGBTIFUnref(in)   ObitUnref (in)
	Macro to unreference (and possibly destroy) an ObitTableGBTIF returns an ObitTableGBTIF*.
#define	ObitTableGBTIFRef(in)   ObitRef (in)
	Macro to reference (update reference count) an ObitTableGBTIF.
#define	ObitTableGBTIFIsA(in)   ObitIsA (in, ObitTableGBTIFGetClass())
	Macro to determine if an object is the member of this or a derived class.
#define	ObitTableGBTIFRowUnref(in)   ObitUnref (in)
	Macro to unreference (and possibly destroy) an ObitTableGBTIFRow returns an ObitTableGBTIFRow*.
#define	ObitTableGBTIFRowRef(in)   ObitRef (in)
	Macro to reference (update reference count) an ObitTableGBTIFRow.
#define	ObitTableGBTIFRowIsA(in)   ObitIsA (in, ObitTableGBTIFRowGetClass())
	Macro to determine if an object is the member of this or a derived class.
Functions
void	ObitTableGBTIFRowClassInit (void)
	Public: Row Class initializer.
ObitTableGBTIFRow *	newObitTableGBTIFRow (ObitTableGBTIF *table)
	Public: Constructor.
gconstpointer	ObitTableGBTIFRowGetClass (void)
	Public: ClassInfo pointer.
void	ObitTableGBTIFClassInit (void)
	Public: Class initializer.
ObitTableGBTIF *	newObitTableGBTIF (gchar *name)
	Public: Constructor.
ObitTableGBTIF *	newObitTableGBTIFValue (gchar *name, Obit *file, glong *ver, ObitIOAccess access, ObitErr *err)
	Public: Constructor from values.
gconstpointer	ObitTableGBTIFGetClass (void)
	Public: ClassInfo pointer.
ObitTableGBTIF *	ObitTableGBTIFCopy (ObitTableGBTIF *in, ObitTableGBTIF *out, ObitErr *err)
	Public: Copy (deep) constructor.
ObitTableGBTIF *	ObitTableGBTIFClone (ObitTableGBTIF *in, ObitTableGBTIF *out)
	Public: Copy (shallow) constructor.
ObitTableGBTIF *	ObitTableGBTIFConvert (ObitTable *in)
	Public: Convert an ObitTable to an ObitTableGBTIF.
ObitIOCode	ObitTableGBTIFOpen (ObitTableGBTIF *in, ObitIOAccess access, ObitErr *err)
	Public: Create ObitIO structures and open file.
ObitIOCode	ObitTableGBTIFReadRow (ObitTableGBTIF *in, glong iIFRow, ObitTableGBTIFRow *row, ObitErr *err)
	Public: Read a table row.
void	ObitTableGBTIFSetRow (ObitTableGBTIF *in, ObitTableGBTIFRow *row, ObitErr *err)
	Public: Init a table row for write.
ObitIOCode	ObitTableGBTIFWriteRow (ObitTableGBTIF *in, glong iIFRow, ObitTableGBTIFRow *row, ObitErr *err)
	Public: Write a table row.
ObitIOCode	ObitTableGBTIFClose (ObitTableGBTIF *in, ObitErr *err)
	Public: Close file and become inactive.

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Detailed Description

ObitTableGBTIF class definition.

Table in GBT archive/IF file. This class contains tabular data and allows access. This class is derived from the ObitTable class.

This class contains tabular data and allows access. ObitTableGBTIF" An ObitTableGBTIF is the front end to a persistent disk resident structure. This class is derived from the ObitTable class.

Table data storage

In memory tables are stored in a fashion similar to how they are stored on disk - in large blocks in memory rather than structures. Due to the word alignment requirements of some machines, they are stored by order of the decreasing element size: double, float long, int, short, char rather than the logical order. The details of the storage in the buffer are kept in the #ObitTableGBTIFDesc.

In addition to the normal tabular data, a table will have a "_status" column to indicate the status of each row. The status value is read from and written to (some modification) AIPS tables but are not written to externally generated FITS tables which don't have these colummns. It will be written to Obit generated tables which will have these columns. Status values:

• status = 0 => normal
• status = 1 => row has been modified (or created) and needs to be written.
• status = -1 => row has been marked invalid.

Specifying desired data transfer parameters

The desired data transfers are specified in the member ObitInfoList. There are separate sets of parameters used to specify the FITS data files. In the following an ObitInfoList entry is defined by the name in double quotes, the data type code as an #ObitInfoType enum and the dimensions of the array (? => depends on application). To specify whether the underlying data files are FITS

• "FileType" OBIT_int (1,1,1) OBIT_IO_FITS which are values of an #ObitIOType enum defined in ObitIO.h.

The following apply to both types of files:

• "nRowPIO", OBIT_int, Max. Number of visibilities per "Read" or "Write" operation. Default = 1.

FITS files

This implementation uses cfitsio which allows using, in addition to regular FITS images, gzip compressed files, pipes, shared memory and a number of other input forms. The convenience Macro #ObitTableGBTIFSetFITS simplifies specifying the desired data. Binary tables are used for storing visibility data in FITS. For accessing FITS files the following entries in the ObitInfoList are used:

• "FileName" OBIT_string (?,1,1) FITS file name.
• "TabName" OBIT_string (?,1,1) Table name (e.g. "AIPS CC").
• "Ver" OBIT_int (1,1,1) Table version number

Creators and Destructors

An ObitTableGBTIF can be created using newObitTableGBTIFValue which attaches the table to an ObitData for the object. If the output ObitTableGBTIF has previously been specified, including file information, then ObitTableGBTIFCopy will copy the disk resident as well as the memory resident information.

A copy of a pointer to an ObitTableGBTIF should always be made using the ObitTableGBTIFRef function which updates the reference count in the object. Then whenever freeing an ObitTableGBTIF or changing a pointer, the function ObitTableGBTIFUnref will decrement the reference count and destroy the object when the reference count hits 0.

I/O

Visibility data is available after an input object is "Opened" and "Read". I/O optionally uses a buffer attached to the ObitTableGBTIF or some external location. To Write an ObitTableGBTIF, create it, open it, and write. The object should be closed to ensure all data is flushed to disk. Deletion of an ObitTableGBTIF after its final unreferencing will automatically close it.

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Define Documentation

#define MAXKEYCHARTABLEIF   24

Number of characters for Table keyword.

#define ObitTableGBTIFIsA (  in   )     ObitIsA (in, ObitTableGBTIFGetClass())

Macro to determine if an object is the member of this or a derived class. Returns TRUE if a member, else FALSE in = object to reference

#define ObitTableGBTIFRef (  in   )     ObitRef (in)

Macro to reference (update reference count) an ObitTableGBTIF. returns an ObitTableGBTIF*. in = object to reference

#define ObitTableGBTIFRowIsA (  in   )     ObitIsA (in, ObitTableGBTIFRowGetClass())

Macro to determine if an object is the member of this or a derived class. Returns TRUE if a member, else FALSE in = object to reference

#define ObitTableGBTIFRowRef (  in   )     ObitRef (in)

Macro to reference (update reference count) an ObitTableGBTIFRow. returns an ObitTableGBTIFRow*. in = object to reference

#define ObitTableGBTIFRowUnref (  in   )     ObitUnref (in)

Macro to unreference (and possibly destroy) an ObitTableGBTIFRow returns an ObitTableGBTIFRow*. in = object to unreference

#define ObitTableGBTIFUnref (  in   )     ObitUnref (in)

Macro to unreference (and possibly destroy) an ObitTableGBTIF returns an ObitTableGBTIF*. in = object to unreference

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Function Documentation

ObitTableGBTIF* newObitTableGBTIF (  gchar *  name  )

Public: Constructor. Initializes class if needed on first call. Parameters: name  An optional name for the object. Returns: the new object.

ObitTableGBTIFRow* newObitTableGBTIFRow (  ObitTableGBTIF *  table  )

Public: Constructor. If table is open and for write, the row is attached to the buffer Initializes Row class if needed on first call. Parameters: name  An optional name for the object. Returns: the new object.

ObitTableGBTIF* newObitTableGBTIFValue (  gchar *  name, Obit *  file, glong *  ver, ObitIOAccess  access, ObitErr *  err )

Public: Constructor from values. Creates a new table structure and attaches to the TableList of file. If the specified table already exists then it is returned. Initializes class if needed on first call. Forces an update of any disk resident structures (e.g. AIPS header). Parameters: name  An optional name for the object. file  ObitData which which the table is to be associated. ver  Table version number. 0=> add higher, value used returned access  access (OBIT_IO_ReadOnly, means do not create if it doesn't exist. err  Error stack, returns if not empty. Returns: the new object, NULL on failure.

void ObitTableGBTIFClassInit (  void   )

Public: Class initializer.

ObitTableGBTIF* ObitTableGBTIFClone (  ObitTableGBTIF *  in, ObitTableGBTIF *  out )

Public: Copy (shallow) constructor.

ObitIOCode ObitTableGBTIFClose (  ObitTableGBTIF *  in, ObitErr *  err )

Public: Close file and become inactive. Parameters: in  Pointer to object to be closed. err  ObitErr for reporting errors. Returns: error code, OBIT_IO_OK=> OK

ObitTableGBTIF* ObitTableGBTIFConvert (  ObitTable *  in  )

Public: Convert an ObitTable to an ObitTableGBTIF. New object will have references to members of in. Parameters: in  The object to copy, will still exist afterwards and should be Unrefed if not needed. Returns: pointer to the new object.

ObitTableGBTIF* ObitTableGBTIFCopy (  ObitTableGBTIF *  in, ObitTableGBTIF *  out, ObitErr *  err )

Public: Copy (deep) constructor. Copies are made of complex members including disk files; these will be copied applying whatever selection is associated with the input. Objects should be closed on input and will be closed on output. In order for the disk file structures to be copied, the output file must be sufficiently defined that it can be written. The copy will be attempted but no errors will be logged until both input and output have been successfully opened. ObitInfoList and ObitThread members are only copied if the output object didn't previously exist. Parent class members are included but any derived class info is ignored. Parameters: in  The object to copy out  An existing object pointer for output or NULL if none exists. err  Error stack, returns if not empty. Returns: pointer to the new object.

gconstpointer ObitTableGBTIFGetClass (  void   )

Public: ClassInfo pointer. Returns: pointer to the class structure.

ObitIOCode ObitTableGBTIFOpen (  ObitTableGBTIF *  in, ObitIOAccess  access, ObitErr *  err )

Public: Create ObitIO structures and open file. The image descriptor is read if OBIT_IO_ReadOnly or OBIT_IO_ReadWrite and written to disk if opened OBIT_IO_WriteOnly. After the file has been opened the member, buffer is initialized for reading/storing the table unless member bufferSize is <0. If the requested version ("Ver" in InfoList) is 0 then the highest numbered table of the same type is opened on Read or Read/Write, or a new table is created on on Write. The file etc. info should have been stored in the ObitInfoList: "FileType" OBIT_int scalar = OBIT_IO_FITS for file type (see class documentation for details). "nRowPIO" OBIT_int scalar = Maximum number of table rows per transfer, this is the target size for Reads (may be fewer) and is used to create buffers. Parameters: in  Pointer to object to be opened. access  access (OBIT_IO_ReadOnly,OBIT_IO_ReadWrite, or OBIT_IO_WriteOnly). If OBIT_IO_WriteOnly any existing data in the output file will be lost. err  ObitErr for reporting errors. Returns: return code, OBIT_IO_OK=> OK

ObitIOCode ObitTableGBTIFReadRow (  ObitTableGBTIF *  in, glong  iIFRow, ObitTableGBTIFRow *  row, ObitErr *  err )

Public: Read a table row. Scalar values are copied but for array values, pointers into the data array are returned. Parameters: in  Table to read iIFRow  Row number, -1 -> next row  Table Row structure to receive data err  ObitErr for reporting errors. Returns: return code, OBIT_IO_OK=> OK

void ObitTableGBTIFRowClassInit (  void   )

Public: Row Class initializer.

gconstpointer ObitTableGBTIFRowGetClass (  void   )

Public: ClassInfo pointer. Returns: pointer to the Row class structure.

void ObitTableGBTIFSetRow (  ObitTableGBTIF *  in, ObitTableGBTIFRow *  row, ObitErr *  err )

Public: Init a table row for write. This is only useful prior to filling a row structure in preparation . for a WriteRow operation. Array members of the Row structure are . pointers to independently allocated memory, this routine allows using . the table IO buffer instead of allocating yet more memory.. This routine need only be called once to initialize a Row structure for write.. Parameters: in  Table with buffer to be written row  Table Row structure to attach err  ObitErr for reporting errors.

ObitIOCode ObitTableGBTIFWriteRow (  ObitTableGBTIF *  in, glong  iIFRow, ObitTableGBTIFRow *  row, ObitErr *  err )

Public: Write a table row. Before calling this routine, the row structure needs to be initialized and filled with data. The array members of the row structure are pointers to independently allocated memory. These pointers can be set to the correct table buffer locations using ObitTableGBTIFSetRow Parameters: in  Table to read iIFRow  Row number, -1 -> next row  Table Row structure containing data err  ObitErr for reporting errors. Returns: return code, OBIT_IO_OK=> OK

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