Functions, Structures, and Data for Data Representation Templates (DRT). More...

#include "grib2_int.h"

Functions
gtemplate *	extdrstemplate (g2int number, g2int *list)
	This subroutine generates the remaining octet map for a given Data Representation Template, if required.

int	g2c_get_drs_template (int drs_template_num, int maplen, int map, int *needext)
	Get DRS template information.

static g2int	getdrsindex (g2int number)
	This function returns the index of specified Data Representation Template.

gtemplate *	getdrstemplate (g2int number)
	This subroutine returns DRS template information for a specified Data Representation Template.

Variables
static const struct drstemplate	templatesdrs [G2C_MAX_DRS_TEMPLATE]
	Stuct holding data for GRIB2 Data Representation Section (DRS) template.

Detailed Description

Functions, Structures, and Data for Data Representation Templates (DRT).

Each Template has three parts:

The number of entries in the template (mapdrslen).
A map of the template (mapdrs), which contains the number of octets in which to pack each of the template values.
A logical value (needext) that indicates whether the Template needs to be extended. In some cases the number of entries in a template can vary depending upon values specified in the "static" part of the template. (See Template 5.1 as an example.)

Note: Array mapdrs contains the number of octets in which the corresponding template values will be stored. A negative value in mapdrs is used to indicate that the corresponding template entry can contain negative values. This information is used later when packing (or unpacking) the template data values. Negative data values in GRIB are stored with the left most bit set to one, and a negative number of octets value in mapdrs indicates that this possibility should be considered. The number of octets used to store the data value in this case would be the absolute value of the negative value in mapdrs.

Program History Log

Date	Programmer	Comments
2001-06-28	Gilbert	Initial
2009-01-14	Vuong	Changed structure name template to gtemplate
2022-10-18	Hartnett	Added g2c_get_drs_template().
2023-09-08	Engle	Added template 5.42.

Author: Stephen Gilbert

Date: 2001-06-28

Definition in file drstemplates.c.

Function Documentation

◆ extdrstemplate()

gtemplate * extdrstemplate	(	g2int	number,
		g2int *	list
	)

This subroutine generates the remaining octet map for a given Data Representation Template, if required.

Some Templates can vary depending on data values given in an earlier part of the Template, and it is necessary to know some of the earlier entry values to generate the full octet map of the Template.

Parameters

number	The number of the Data Representation Template that is being requested.
list	The list of values for each entry in the the Data Representation Template.

Returns: Pointer to the returned template struct. Returns NULL pointer, if template not found.

Author: Stephen Gilbert

Date: 2000-05-11

Definition at line 213 of file drstemplates.c.

References getdrsindex(), and getdrstemplate().

Referenced by g2_unpack5().

◆ g2c_get_drs_template()

int g2c_get_drs_template	(	int	drs_template_num,
		int *	maplen,
		int *	map,
		int *	needext
	)

Get DRS template information.

The DRS template consists of a template map, and its length. There are no supported DRS templates with extensions.

Parameters

drs_template_num	The DRS template number.
maplen	Pointer that gets the length of the map. Ignored if NULL.
map	Pointer that gets the map as an array of int. Memory must be allocated by caller. Ignored if NULL.
needext	Pointer that a non-zero value if an extension to this template is needed. Ignored if NULL.

Returns

G2C_NOERROR No error.
G2C_ENOTEMPLATE Template not found.

Author: Ed Hartnett

Date: 10/18/22

Definition at line 261 of file drstemplates.c.

References G2C_ENOTEMPLATE, G2C_MAX_DRS_TEMPLATE, G2C_NOERROR, and templatesdrs.

Referenced by g2c_rw_section5_metadata().

◆ getdrsindex()

static g2int getdrsindex ( g2int number )

static

This function returns the index of specified Data Representation Template.

Parameters

number The number of the Data Representation Template that is being requested.

Returns: Index of the DRT in array gtemplates, if it exists. -1, otherwise.

Author: Stephen Gilbert

Date: 2001-06-28

Definition at line 135 of file drstemplates.c.

References G2C_MAX_DRS_TEMPLATE, getdrsindex(), and templatesdrs.

Referenced by extdrstemplate(), getdrsindex(), and getdrstemplate().

◆ getdrstemplate()

gtemplate * getdrstemplate ( g2int number )

This subroutine returns DRS template information for a specified Data Representation Template.

The number of entries in the template is returned along with a map of the number of octets occupied by each entry. Also, a flag is returned to indicate whether the template would need to be extended.

Parameters

number The number of the Data Representation Template that is being requested.

Returns: Pointer to the returned template struct. Returns NULL if template not found.

Author: Stephen Gilbert

Date: 2000-05-11

Definition at line 167 of file drstemplates.c.

References getdrsindex(), and templatesdrs.

Referenced by extdrstemplate(), g2_addfield(), and g2_unpack5().

Variable Documentation

◆ templatesdrs

const struct drstemplate templatesdrs[G2C_MAX_DRS_TEMPLATE]

static

Stuct holding data for GRIB2 Data Representation Section (DRS) template.

Definition at line 53 of file drstemplates.c.

Referenced by g2c_get_drs_template(), getdrsindex(), and getdrstemplate().

Functions

Variables

Detailed Description

Program History Log

Function Documentation

◆ extdrstemplate()

◆ g2c_get_drs_template()

◆ getdrsindex()

◆ getdrstemplate()

Variable Documentation

◆ templatesdrs