Write summary output to an index file, as is done by utility grb2index. More...

#include "grib2_int.h"
#include <time.h>
#include <stdarg.h>
#include <libgen.h>

Macros
#define	G2C_INDEX_BASENAME_LEN 40
	Length of the basename in header record 2.

#define	G2C_INDEX_BITMAP_BYTES 6
	Length of bitmap section included in the index record.

#define	G2C_INDEX_DATE_STR_LEN 10
	Length of date string in index record.

#define	G2C_INDEX_FIXED_LEN 44
	Length of beginning of index record.

#define	G2C_INDEX_FIXED_LEN_2 48
	Length of beginning of index record for large files.

#define	G2C_INDEX_HEADER_LEN 81
	Length of the two header lines at the top of the index file.

#define	G2C_INDEX_STR1_LEN 7
	Length of str1 string in index record.

#define	G2C_INDEX_TIME_STR_LEN 8
	Length of time string in index record.

Functions
	EXTERN_MUTEX (m)
	Use externally-defined mutex for thread-safety.

int	g2c_get_prod_sections (G2C_MESSAGE_INFO_T msg, int fieldnum, G2C_SECTION_INFO_T sec3, G2C_SECTION_INFO_T sec4, G2C_SECTION_INFO_T sec5, G2C_SECTION_INFO_T sec6, G2C_SECTION_INFO_T *sec7)
	Given a pointer to a message, and a field number, return pointers to all relevent section structs for that product.

int	g2c_open_index (const char data_file, const char index_file, int mode, int *g2cid)
	Open a GRIB2 file with the help of an index file.

int	g2c_open_index1 (const char *index_file)
	Open a GRIB1 index file and read the contents.

int	g2c_start_index1_record (FILE f, int rw_flag, unsigned int b2_msg, unsigned int b2_pds, unsigned int b2_gds, unsigned int b2_bms, unsigned int b2_bds, unsigned int msglen, unsigned char version, unsigned char pds_val, unsigned char gds_val, unsigned char bms_val, unsigned char bds_val, unsigned char pds_val2, unsigned char pds_val3, unsigned char *gds_val2)
	Read or write the start of a version 1 index record.

int	g2c_start_index_record (FILE f, int rw_flag, int reclen, int msg, int local, int gds, int pds, int drs, int bms, int data, size_t msglen, unsigned char version, unsigned char discipline, short *fieldnum)
	Read or write the start of a version 2 index record.

int	g2c_start_index_record_lf (FILE f, int rw_flag, int reclen, size_t msg, int local, int gds, int pds, int drs, int bms, int data, size_t msglen, unsigned char version, unsigned char discipline, short *fieldnum)
	Read or write the start of a version 2 index record for large file.

int	g2c_write_index (int g2cid, int mode, const char *index_file)
	Create an index file from a GRIB2 file, just like those created by the grb2index utility.

static int	read_hdr_rec1 (FILE f, int ip, int jp, int kp, char date_str, char time_str)
	Read the header record apparently named after Steve Lord.

static int	read_hdr_rec2 (FILE f, int skipp, int total_lenp, int num_recp, char basename, int index_version)
	Read the second header record of an index file.

Variables
G2C_FILE_INFO_T	g2c_file [G2C_MAX_FILES+1]
	Global file information.

Detailed Description

Write summary output to an index file, as is done by utility grb2index.

Author: Ed Hartnett

Date: 10/12/22

Definition in file g2cindex.c.

Macro Definition Documentation

◆ G2C_INDEX_BASENAME_LEN

#define G2C_INDEX_BASENAME_LEN 40

Length of the basename in header record 2.

Definition at line 20 of file g2cindex.c.

◆ G2C_INDEX_BITMAP_BYTES

#define G2C_INDEX_BITMAP_BYTES 6

Length of bitmap section included in the index record.

Definition at line 23 of file g2cindex.c.

◆ G2C_INDEX_DATE_STR_LEN

#define G2C_INDEX_DATE_STR_LEN 10

Length of date string in index record.

Definition at line 32 of file g2cindex.c.

◆ G2C_INDEX_FIXED_LEN

#define G2C_INDEX_FIXED_LEN 44

Length of beginning of index record.

Definition at line 26 of file g2cindex.c.

◆ G2C_INDEX_FIXED_LEN_2

#define G2C_INDEX_FIXED_LEN_2 48

Length of beginning of index record for large files.

Definition at line 29 of file g2cindex.c.

◆ G2C_INDEX_HEADER_LEN

#define G2C_INDEX_HEADER_LEN 81

Length of the two header lines at the top of the index file.

Definition at line 17 of file g2cindex.c.

◆ G2C_INDEX_STR1_LEN

#define G2C_INDEX_STR1_LEN 7

Length of str1 string in index record.

Definition at line 38 of file g2cindex.c.

◆ G2C_INDEX_TIME_STR_LEN

#define G2C_INDEX_TIME_STR_LEN 8

Length of time string in index record.

Definition at line 35 of file g2cindex.c.

Function Documentation

◆ EXTERN_MUTEX()

EXTERN_MUTEX ( m )

Use externally-defined mutex for thread-safety.

◆ g2c_get_prod_sections()

int g2c_get_prod_sections	(	G2C_MESSAGE_INFO_T *	msg,
		int	fieldnum,
		G2C_SECTION_INFO_T **	sec3,
		G2C_SECTION_INFO_T **	sec4,
		G2C_SECTION_INFO_T **	sec5,
		G2C_SECTION_INFO_T **	sec6,
		G2C_SECTION_INFO_T **	sec7
	)

Given a pointer to a message, and a field number, return pointers to all relevent section structs for that product.

Each product is defined in a section 4, and has an associated section 3, 5, 6, and 7.

Parameters

msg	Pointer to a G2C_MESSAGE_INFO_T with information about the message.
fieldnum	The field number (first field in message is 0).
sec3	Pointer that gets a pointer to the G2C_SECTION_INFO_T struct for the section 3 associated with this product.
sec4	Pointer that gets a pointer to the G2C_SECTION_INFO_T struct for the section 4 associated with this product.
sec5	Pointer that gets a pointer to the G2C_SECTION_INFO_T struct for the section 5 associated with this product.
sec6	Pointer that gets a pointer to the G2C_SECTION_INFO_T struct for the section 6 associated with this product. NULL is returned if there is no section 6.
sec7	Pointer that gets a pointer to the G2C_SECTION_INFO_T struct for the section 7 associated with this product.

Note: This is an internal function and should not be called by users.

Returns

G2C_NOERROR No error.
G2C_EINVAL Invalid input.
G2C_ENOSECTION Section not found.

Author: Ed Hartnett

Date: 10/27/22

Definition at line 319 of file g2cindex.c.

References G2C_EINVAL, G2C_ENOSECTION, G2C_NOERROR, g2c_section_info::next, g2c_section_info::prev, g2c_message_info::sec, g2c_section_info::sec_info, and g2c_section_info::sec_num.

Referenced by g2c_write_index().

◆ g2c_open_index()

int g2c_open_index	(	const char *	data_file,
		const char *	index_file,
		int	mode,
		int *	g2cid
	)

Open a GRIB2 file with the help of an index file.

The index file, generated by the grb2index utility, of the g2c_write_index() function, contains the byte offsets for the sections of each message in the GRIB2 file. When a GRIB2 file is opened with an index file, the library does not have to scan the file to locate all metadata.

Parameters

data_file	The name of the data file to which the index applies.
index_file	The name that will be given to the index file. An existing file will be overwritten.
mode	Open mode flags.
g2cid	Pointer that gets the g2cid for this file. Ignored if NULL.

Returns

G2C_NOERROR No error.

Author: Ed Hartnett

Date: 10/12/22

Definition at line 895 of file g2cindex.c.

References add_msg(), add_section(), g2c_message_info::bytes_to_bms, g2c_message_info::bytes_to_data, g2c_message_info::bytes_to_local, g2c_message_info::bytes_to_msg, g2c_message_info::discipline, g2c_add_file(), G2C_EBADSECTION, G2C_EFILE, G2C_EINVAL, G2C_ENAMETOOLONG, g2c_file, g2c_file_io_ubyte(), g2c_file_io_uint(), G2C_FILE_READ, G2C_INDEX_BASENAME_LEN, G2C_INDEX_DATE_STR_LEN, G2C_INDEX_HEADER_LEN, G2C_INDEX_STR1_LEN, G2C_INDEX_TIME_STR_LEN, g2c_log_section1(), G2C_MAX_NAME, G2C_NOERROR, g2c_rw_section1_metadata(), g2c_start_index_record(), g2c_start_index_record_lf(), LOG, g2c_message_info::master_version, MUTEX_LOCK, and MUTEX_UNLOCK.

Referenced by main().

◆ g2c_open_index1()

int g2c_open_index1 ( const char * index_file )

Open a GRIB1 index file and read the contents.

Parameters

index_file The name that will be given to the index file. An existing file will be overwritten.

Returns

G2C_NOERROR No error.

Author: Ed Hartnett

Date: 10/12/22

Definition at line 793 of file g2cindex.c.

References G2C_EFILE, G2C_EINVAL, G2C_FILE_READ, G2C_INDEX1_BDS_VAL_LEN, G2C_INDEX1_BMS_VAL_LEN, G2C_INDEX1_GDS_VAL_LEN, G2C_INDEX1_PDS_VAL_LEN, G2C_INDEX_BASENAME_LEN, G2C_INDEX_DATE_STR_LEN, G2C_INDEX_HEADER_LEN, G2C_INDEX_TIME_STR_LEN, G2C_NOERROR, g2c_start_index1_record(), LOG, MUTEX_LOCK, MUTEX_UNLOCK, read_hdr_rec1(), and read_hdr_rec2().

◆ g2c_start_index1_record()

int g2c_start_index1_record	(	FILE *	f,
		int	rw_flag,
		unsigned int *	b2_msg,
		unsigned int *	b2_pds,
		unsigned int *	b2_gds,
		unsigned int *	b2_bms,
		unsigned int *	b2_bds,
		unsigned int *	msglen,
		unsigned char *	version,
		unsigned char *	pds_val,
		unsigned char *	gds_val,
		unsigned char *	bms_val,
		unsigned char *	bds_val,
		unsigned char *	pds_val2,
		unsigned char *	pds_val3,
		unsigned char *	gds_val2
	)

Read or write the start of a version 1 index record.

For more detail on version 1 of the index format, see the grbindex documentation in the NCEPLIBS-grib_util.

Parameters

f	FILE * to open index file.
rw_flag	True if function should write, false if it should read.
b2_msg	Pointer that gets the bytes to skip in file before msg.
b2_pds	Pointer that gets bytes to skip in message before pds.
b2_gds	Pointer that gets bytes to skip in message before gds (0 if no gds).
b2_bms	Pointer that gets bytes to skip in message before bms (0 if no bms).
b2_bds	Pointer that gets bytes to skip in message before bds.
msglen	Pointer that gets bytes total in the message.
version	Pointer that gets grib version number (always 1 for this function).
pds_val	Pointer that gets an arry of 27 bytes of the product definition section (pds).
gds_val	Pointer that gets an arry of 41 bytes of the gds.
bms_val	Pointer that gets an arry of 5 bytes of the bms.
bds_val	Pointer that gets an arry of 10 bytes, bytes 41-100 of the bds.
pds_val2	Pointer that gets an arry of 59 bytes 41-100 of the pds. Ignored if null.
pds_val3	Pointer that gets an arry of 11 bytes 29-40 of the pds. Ignored if null.
gds_val2	Pointer that gets an arry of 135 bytes 43-178 of the gds. Ignored if null.

Returns

G2C_NOERROR No error.
G2C_EINVAL Invalid input.
G2C_EFILE File I/O error.

Author: Ed Hartnett 9/11/23

Definition at line 240 of file g2cindex.c.

References G2C_EFILE, G2C_EINVAL, g2c_file_io_ubyte(), g2c_file_io_uint(), G2C_INDEX1_BDS_VAL_LEN, G2C_INDEX1_BMS_VAL_LEN, G2C_INDEX1_GDS_VAL_LEN, G2C_INDEX1_PDS_VAL_LEN, and G2C_NOERROR.

Referenced by g2c_open_index1().

◆ g2c_start_index_record()

int g2c_start_index_record	(	FILE *	f,
		int	rw_flag,
		int *	reclen,
		int *	msg,
		int *	local,
		int *	gds,
		int *	pds,
		int *	drs,
		int *	bms,
		int *	data,
		size_t *	msglen,
		unsigned char *	version,
		unsigned char *	discipline,
		short *	fieldnum
	)

Read or write the start of a version 2 index record.

Parameters

f	FILE * to open index file.
rw_flag	True if function should write, false if it should read.
reclen	Pointer to reclen.
msg	Pointer to msg.
local	Pointer to local.
gds	Pointer to gds.
pds	Pointer to pds.
drs	Pointer to drs.
bms	Pointer to bms.
data	Pointer to data.
msglen	Pointer to msglen.
version	Pointer to version.
discipline	Pointer to discipline.
fieldnum	Pointer to fieldnum, 0- based. (It is 1-based in the index file.)

Returns

G2C_NOERROR No error.
G2C_EINVAL Invalid input.
G2C_EFILE File I/O error.

Author: Ed Hartnett 10/26/22

Definition at line 70 of file g2cindex.c.

References G2C_EINVAL, g2c_file_io_short(), g2c_file_io_ubyte(), g2c_file_io_uint(), g2c_file_io_ulonglong(), G2C_NOERROR, and LOG.

Referenced by g2c_open_index(), and g2c_write_index().

◆ g2c_start_index_record_lf()

int g2c_start_index_record_lf	(	FILE *	f,
		int	rw_flag,
		int *	reclen,
		size_t *	msg,
		int *	local,
		int *	gds,
		int *	pds,
		int *	drs,
		int *	bms,
		int *	data,
		size_t *	msglen,
		unsigned char *	version,
		unsigned char *	discipline,
		short *	fieldnum
	)

Read or write the start of a version 2 index record for large file.

Parameters

f	FILE * to open index file.
rw_flag	True if function should write, false if it should read.
reclen	Pointer to reclen.
msg	Pointer to msg.
local	Pointer to local.
gds	Pointer to gds.
pds	Pointer to pds.
drs	Pointer to drs.
bms	Pointer to bms.
data	Pointer to data.
msglen	Pointer to msglen.
version	Pointer to version.
discipline	Pointer to discipline.
fieldnum	Pointer to fieldnum, 0- based. (It is 1-based in the index file.)

Returns

G2C_NOERROR No error.
G2C_EINVAL Invalid input.
G2C_EFILE File I/O error.

Author: Ed Hartnett 10/26/22

Definition at line 152 of file g2cindex.c.

References G2C_EINVAL, g2c_file_io_short(), g2c_file_io_ubyte(), g2c_file_io_uint(), g2c_file_io_ulonglong(), G2C_NOERROR, and LOG.

Referenced by g2c_open_index(), and g2c_write_index().

◆ g2c_write_index()

int g2c_write_index	(	int	g2cid,
		int	mode,
		const char *	index_file
	)

Create an index file from a GRIB2 file, just like those created by the grb2index utility.

The index file starts with two header records:

81-byte header with 'gb2ix1' in columns 42-47.
81-byte header with number of bytes to skip before index records, total length in bytes of the index records, number of index records, and grib file basename written in format ('ix1form:',3i10,2x,a40).

Each following index record corresponds to a grib message and has the internal format:

byte 001 - 004 length of index record
byte 005 - 008 bytes to skip in data file before grib message
byte 009 - 012 bytes to skip in message before lus (local use) (0, if none).
byte 013 - 016 bytes to skip in message before gds
byte 017 - 020 bytes to skip in message before pds
byte 021 - 024 bytes to skip in message before drs
byte 025 - 028 bytes to skip in message before bms
byte 029 - 032 bytes to skip in message before data section
byte 033 - 040 bytes total in the message
byte 041 - 041 grib version number (currently 2)
byte 042 - 042 message discipline
byte 043 - 044 field number within grib2 message (1-based)
byte 045 - ii identification section (ids)
byte ii+1- jj grid definition section (gds)
byte jj+1- kk product definition section (pds)
byte kk+1- ll the data representation section (drs)
byte ll+1-ll+6 first 6 bytes of the bit map section (bms)

Parameters

g2cid	File it for an open GRIB2 file, as returned by g2c_open().
mode	Mode flags. Set G2C_NOCLOBBER to avoid overwriting and existing file.
index_file	The name that will be given to the index file. An existing file will be overwritten.

Returns

G2C_NOERROR No error.

Author: Ed Hartnett

Date: 10/12/22

Definition at line 433 of file g2cindex.c.

References g2c_message_info::bytes_in_msg, g2c_message_info::bytes_to_local, g2c_message_info::bytes_to_msg, g2c_section_info::bytes_to_sec, g2c_message_info::discipline, g2c_file_info::f, g2c_message_info::file, G2C_EBADID, G2C_EFILE, G2C_EINVAL, g2c_file, g2c_file_io_ubyte(), g2c_file_io_uint(), G2C_FILE_WRITE, g2c_get_prod_sections(), G2C_INDEX_BASENAME_LEN, G2C_INDEX_BITMAP_BYTES, G2C_INDEX_FIXED_LEN, G2C_INDEX_FIXED_LEN_2, G2C_INDEX_HEADER_LEN, G2C_LARGE_FILE_INDEX, G2C_MAX_FILES, G2C_NOCLOBBER, G2C_NOERROR, g2c_rw_section1_metadata(), g2c_rw_section3_metadata(), g2c_rw_section4_metadata(), g2c_rw_section5_metadata(), g2c_start_index_record(), g2c_start_index_record_lf(), LOG, g2c_message_info::master_version, MUTEX_LOCK, MUTEX_UNLOCK, g2c_message_info::next, g2c_message_info::num_fields, ONE_BYTE, g2c_message_info::sec1_len, and g2c_section_info::sec_len.

Referenced by main().

◆ read_hdr_rec1()

static int read_hdr_rec1	(	FILE *	f,
		int *	ip,
		int *	jp,
		int *	kp,
		char *	date_str,
		char *	time_str
	)

static

Read the header record apparently named after Steve Lord.

This function reads the first of two 81-byte header records of an index file.

Parameters

f	Pointer to open FILE.
ip	Pointer that gets i value. Ignored if NULL.
jp	Pointer that gets j value. Ignored if NULL.
kp	Pointer that gets k value. Ignored if NULL.
date_str	Pointer to char array of size G2C_INDEX_DATE_STR_LEN + 1 which will get the date string from the header. Ignored if NULL.
time_str	Pointer to char array of size G2C_INDEX_TIME_STR_LEN + 1 which will get the time string from the header. Ignored if NULL.

Returns: 0 for success, error code otherwise.

Author: Edward Hartnett

Date: 9/10/23

Definition at line 677 of file g2cindex.c.

References G2C_EFILE, G2C_INDEX_DATE_STR_LEN, G2C_INDEX_HEADER_LEN, G2C_INDEX_STR1_LEN, G2C_INDEX_TIME_STR_LEN, G2C_NOERROR, and LOG.

Referenced by g2c_open_index1().

◆ read_hdr_rec2()

static int read_hdr_rec2	(	FILE *	f,
		int *	skipp,
		int *	total_lenp,
		int *	num_recp,
		char *	basename,
		int *	index_version
	)

static

Read the second header record of an index file.

This function reads the second of two 81-byte header records of an index file.

Parameters

f	Pointer to open FILE.
skipp	Pointer that gets number of bytes to skip before index records. Ignored if NULL.
total_lenp	Pointer that gets number of bytes in each index record. Ignored if NULL.
num_recp	Pointer that gets number of index records in the file. Ignored if NULL.
basename	Pointer to char array of size G2C_INDEX_BASENAME_LEN + 1 which will get the basename string from the second header record. Ignored if NULL.
index_version	The version of the index, 1 for legacy, 2 to allow for > 2 GB GRIB2 files.

Returns: 0 for success, error code otherwise.

Author: Edward Hartnett

Date: 9/10/23

Definition at line 746 of file g2cindex.c.

References G2C_EFILE, G2C_INDEX_BASENAME_LEN, G2C_INDEX_HEADER_LEN, and G2C_NOERROR.

Referenced by g2c_open_index1().

Variable Documentation

◆ g2c_file

G2C_FILE_INFO_T g2c_file[G2C_MAX_FILES+1]

extern

Global file information.

Definition at line 10 of file g2cfile.c.

Referenced by g2c_open_index(), and g2c_write_index().

Macros

Functions

Variables

Detailed Description

Macro Definition Documentation

◆ G2C_INDEX_BASENAME_LEN

◆ G2C_INDEX_BITMAP_BYTES

◆ G2C_INDEX_DATE_STR_LEN

◆ G2C_INDEX_FIXED_LEN

◆ G2C_INDEX_FIXED_LEN_2

◆ G2C_INDEX_HEADER_LEN

◆ G2C_INDEX_STR1_LEN

◆ G2C_INDEX_TIME_STR_LEN

Function Documentation

◆ EXTERN_MUTEX()

◆ g2c_get_prod_sections()

◆ g2c_open_index()

◆ g2c_open_index1()

◆ g2c_start_index1_record()

◆ g2c_start_index_record()

◆ g2c_start_index_record_lf()

◆ g2c_write_index()

◆ read_hdr_rec1()

◆ read_hdr_rec2()

Variable Documentation

◆ g2c_file