nxt4meta.c File Reference

NEXTCDF-4 Sprint 3 metadata model: dimensions, variables, attributes, type mapping, and on-disk discovery. More...

#include "config.h"
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include <hdf5_hl.h>
#include "nclist.h"
#include "nxt4internal.h"

Data Structures
struct	dim_list_t
struct	var_list_t
struct	resolve_scale_t
struct	att_iter_data_t
struct	load_children_data_t

Functions
static int	is_reserved_att (const char *name)
static void	free_name_list (char **names, size_t n)
int	NEXTCDF4_check_write_define (NEXTCDF4_FILE_INFO_T *file)
int	NEXTCDF4_map_hdf_type (nc_type xtype, hid_t *typep)
int	NEXTCDF4_type_size (nc_type xtype, size_t *sizep)
const char *	NEXTCDF4_type_name (nc_type xtype)
int	NEXTCDF4_check_atomic_type (NEXTCDF4_FILE_INFO_T *file, nc_type xtype)
static hid_t	native_hdf_type (nc_type xtype)
static int	set_var_type (NC_VAR_INFO_T *var, nc_type xtype)
static int	write_string_att (hid_t loc, const char *name, const char *value)
static int	write_int_att (hid_t loc, const char *name, int value)
static int	write_int_array_att (hid_t loc, const char *name, const int *values, size_t len)
static int	map_nc_type (hid_t htype, nc_type *xtypep)
static int	get_att_context (NC_GRP_INFO_T *grp, NC_VAR_INFO_T *var, NCindex **listp, hid_t *locp)
static NC_ATT_INFO_T *	find_att (NCindex *list, const char *name)
static int	add_att (NCindex *list, NC_OBJ *container, const char *name, nc_type xtype, size_t len, const void *data, NC_ATT_INFO_T **attp)
static int	read_hdf5_att (hid_t loc, const char *name, NCindex *list, NC_OBJ *container)
int	NEXTCDF4_def_dim (int ncid, const char *name, size_t len, int *idp)
int	NEXTCDF4_inq_dim (int ncid, int dimid, char *name, size_t *lenp)
int	NEXTCDF4_def_var (int ncid, const char *name, nc_type xtype, int ndims, const int *dimidsp, int *varidp)
static int	create_var_dataset (NC_VAR_INFO_T *var, NC_FILE_INFO_T *h5, NEXTCDF4_FILE_INFO_T *file, NC_GRP_INFO_T *grp)
static int	find_var_for_write (int ncid, int varid, NC_FILE_INFO_T **h5, NEXTCDF4_FILE_INFO_T **file, NC_GRP_INFO_T **grp, NC_VAR_INFO_T **var)
int	NEXTCDF4_def_var_chunking (int ncid, int varid, int storage, const size_t *chunksizesp)
int	NEXTCDF4_def_var_deflate (int ncid, int varid, int shuffle, int deflate, int deflate_level)
int	NEXTCDF4_def_var_fletcher32 (int ncid, int varid, int fletcher32)
int	NEXTCDF4_def_var_fill (int ncid, int varid, int no_fill, const void *fill_value)
int	NEXTCDF4_def_var_endian (int ncid, int varid, int endianness)
int	NEXTCDF4_def_var_quantize (int ncid, int varid, int quantize_mode, int nsd)
int	NEXTCDF4_def_var_filter (int ncid, int varid, unsigned int id, size_t nparams, const unsigned int *params)
int	NEXTCDF4_inq_var_all (int ncid, int varid, char *name, nc_type *xtypep, int *ndimsp, int *dimidsp, int *nattsp, int *shufflep, int *deflatep, int *deflate_levelp, int *fletcher32p, int *contiguousp, size_t *chunksizesp, int *no_fillp, void *fill_valuep, int *endiannessp, unsigned int *idp, size_t *nparamsp, unsigned int *params)
int	NEXTCDF4_inq_var (int ncid, int varid, char *name, nc_type *xtypep, int *ndimsp, int *dimidsp, int *nattsp)
int	NEXTCDF4_inq_var_filter_ids (int ncid, int varid, size_t *nfiltersp, unsigned int *ids)
int	NEXTCDF4_inq_var_filter_info (int ncid, int varid, unsigned int id, size_t *nparamsp, unsigned int *params)
int	NEXTCDF4_put_att (int ncid, int varid, const char *name, nc_type datatype, size_t len, const void *value, nc_type memtype)
int	NEXTCDF4_get_att (int ncid, int varid, const char *name, void *value, nc_type memtype)
int	NEXTCDF4_rename_att (int ncid, int varid, const char *name, const char *newname)
static NC_VAR_INFO_T *	find_coord_var (NC_GRP_INFO_T *grp, NC_DIM_INFO_T *dim)
static NC_DIM_INFO_T *	coord_var_dim (NC_VAR_INFO_T *var)
int	NEXTCDF4_rename_dim (int ncid, int dimid, const char *name)
int	NEXTCDF4_rename_var (int ncid, int varid, const char *name)
int	NEXTCDF4_del_att (int ncid, int varid, const char *name)
static herr_t	find_dim_cb (hid_t loc, const char *name, const H5L_info_t *info, void *op_data)
static int	load_one_dim (NEXTCDF4_FILE_INFO_T *file, NC_GRP_INFO_T *grp, const char *name, int dimid)
static int	load_dimensions (NEXTCDF4_FILE_INFO_T *file, NC_FILE_INFO_T *h5, NC_GRP_INFO_T *grp)
static herr_t	find_var_cb (hid_t loc, const char *name, const H5L_info_t *info, void *op_data)
static NC_DIM_INFO_T *	find_dim_by_name (NC_GRP_INFO_T *grp, const char *name)
static int	scale_resolve_visitor (hid_t did, unsigned int dim, hid_t dsid, void *op_data)
static int	resolve_var_dimids (NC_GRP_INFO_T *grp, hid_t dset, int ndims, int *dimids)
static int	load_one_var (NEXTCDF4_FILE_INFO_T *file, NC_FILE_INFO_T *h5, NC_GRP_INFO_T *grp, const char *name, int varid)
static herr_t	load_att_cb (hid_t loc, const char *attr_name, const H5A_info_t *ainfo, void *op_data)
static int	load_variables (NEXTCDF4_FILE_INFO_T *file, NC_FILE_INFO_T *h5, NC_GRP_INFO_T *grp)
static int	load_group_attributes (NEXTCDF4_FILE_INFO_T *file, NC_FILE_INFO_T *h5, NC_GRP_INFO_T *grp)
static int	load_children (NEXTCDF4_FILE_INFO_T *file, NC_FILE_INFO_T *h5, hid_t parent_hdf, NC_GRP_INFO_T *parent)
static int	load_one_type (NC_GRP_INFO_T *grp, hid_t htype, const char *name)
static int	load_group_metadata (NEXTCDF4_FILE_INFO_T *file, NC_FILE_INFO_T *h5, NC_GRP_INFO_T *grp, hid_t hdf_grp)
static int	load_one_group (NEXTCDF4_FILE_INFO_T *file, NC_FILE_INFO_T *h5, NC_GRP_INFO_T *parent, hid_t parent_hdf, const char *name)
static herr_t	load_children_cb (hid_t loc, const char *name, const H5L_info_t *info, void *op_data)
int	NEXTCDF4_load_metadata (NEXTCDF4_FILE_INFO_T *file, NC_FILE_INFO_T *h5)

Variables
static const char *	reserved_atts []

Detailed Description

NEXTCDF-4 Sprint 3 metadata model: dimensions, variables, attributes, type mapping, and on-disk discovery.

Author

Edward Hartnett

Date

2026-08-28

Copyright

Intelligent Data Design, Inc. All rights reserved.

Function Documentation

add_att()

static int add_att ( NCindex *  list, NC_OBJ *  container, const char *  name, nc_type  xtype, size_t  len, const void *  data, NC_ATT_INFO_T **  attp  )

static

coord_var_dim()

static NC_DIM_INFO_T * coord_var_dim ( NC_VAR_INFO_T *  var )

static

create_var_dataset()

static int create_var_dataset ( NC_VAR_INFO_T *  var, NC_FILE_INFO_T *  h5, NEXTCDF4_FILE_INFO_T *  file, NC_GRP_INFO_T *  grp  )

static

find_att()

static NC_ATT_INFO_T * find_att ( NCindex *  list, const char *  name  )

static

find_coord_var()

static NC_VAR_INFO_T * find_coord_var ( NC_GRP_INFO_T *  grp, NC_DIM_INFO_T *  dim  )

static

find_dim_by_name()

static NC_DIM_INFO_T * find_dim_by_name ( NC_GRP_INFO_T *  grp, const char *  name  )

static

find_dim_cb()

static herr_t find_dim_cb ( hid_t  loc, const char *  name, const H5L_info_t *  info, void *  op_data  )

static

find_var_cb()

static herr_t find_var_cb ( hid_t  loc, const char *  name, const H5L_info_t *  info, void *  op_data  )

static

find_var_for_write()

static int find_var_for_write ( int  ncid, int  varid, NC_FILE_INFO_T **  h5, NEXTCDF4_FILE_INFO_T **  file, NC_GRP_INFO_T **  grp, NC_VAR_INFO_T **  var  )

static

free_name_list()

static void free_name_list ( char **  names, size_t  n  )

static

get_att_context()

static int get_att_context ( NC_GRP_INFO_T *  grp, NC_VAR_INFO_T *  var, NCindex **  listp, hid_t *  locp  )

static

is_reserved_att()

static int is_reserved_att ( const char *  name )

static

load_att_cb()

static herr_t load_att_cb ( hid_t  loc, const char *  attr_name, const H5A_info_t *  ainfo, void *  op_data  )

static

load_children()

static int load_children ( NEXTCDF4_FILE_INFO_T *  file, NC_FILE_INFO_T *  h5, hid_t  parent_hdf, NC_GRP_INFO_T *  parent  )

static

load_children_cb()

static herr_t load_children_cb ( hid_t  loc, const char *  name, const H5L_info_t *  info, void *  op_data  )

static

load_dimensions()

static int load_dimensions ( NEXTCDF4_FILE_INFO_T *  file, NC_FILE_INFO_T *  h5, NC_GRP_INFO_T *  grp  )

static

load_group_attributes()

static int load_group_attributes ( NEXTCDF4_FILE_INFO_T *  file, NC_FILE_INFO_T *  h5, NC_GRP_INFO_T *  grp  )

static

load_group_metadata()

static int load_group_metadata ( NEXTCDF4_FILE_INFO_T *  file, NC_FILE_INFO_T *  h5, NC_GRP_INFO_T *  grp, hid_t  hdf_grp  )

static

load_one_dim()

static int load_one_dim ( NEXTCDF4_FILE_INFO_T *  file, NC_GRP_INFO_T *  grp, const char *  name, int  dimid  )

static

load_one_group()

static int load_one_group ( NEXTCDF4_FILE_INFO_T *  file, NC_FILE_INFO_T *  h5, NC_GRP_INFO_T *  parent, hid_t  parent_hdf, const char *  name  )

static

load_one_type()

static int load_one_type ( NC_GRP_INFO_T *  grp, hid_t  htype, const char *  name  )

static

load_one_var()

static int load_one_var ( NEXTCDF4_FILE_INFO_T *  file, NC_FILE_INFO_T *  h5, NC_GRP_INFO_T *  grp, const char *  name, int  varid  )

static

load_variables()

static int load_variables ( NEXTCDF4_FILE_INFO_T *  file, NC_FILE_INFO_T *  h5, NC_GRP_INFO_T *  grp  )

static

map_nc_type()

static int map_nc_type ( hid_t  htype, nc_type *  xtypep  )

static

native_hdf_type()

static hid_t native_hdf_type ( nc_type  xtype )

static

NEXTCDF4_check_atomic_type()

int NEXTCDF4_check_atomic_type	(	NEXTCDF4_FILE_INFO_T *	file,
		nc_type	xtype
	)

Validate a fixed-size atomic type for the active model.

Parameters

file	NEXTCDF-4 file state.
xtype	Candidate NetCDF type.

Returns

NC_NOERR or NC_EBADTYPE/NC_ENOTNC4.

NEXTCDF4_check_write_define()

int NEXTCDF4_check_write_define

(

NEXTCDF4_FILE_INFO_T *

file

)

Verify the file is in define mode and not read-only.

Parameters

file	NEXTCDF-4 file state.

Returns

NC_NOERR or an appropriate NetCDF error code.

NEXTCDF4_def_dim()

int NEXTCDF4_def_dim	(	int	ncid,
		const char *	name,
		size_t	len,
		int *	idp
	)

Define a dimension in the root group.

Parameters

ncid	NetCDF file identifier.
name	Dimension name.
len	Dimension length, or 0 for unlimited.
idp	Destination for the assigned dimension id.

Returns

NC_NOERR on success, or a NetCDF error code.

NEXTCDF4_def_var()

int NEXTCDF4_def_var	(	int	ncid,
		const char *	name,
		nc_type	xtype,
		int	ndims,
		const int *	dimidsp,
		int *	varidp
	)

Define a fixed-size atomic variable in the root group.

Parameters

ncid	NetCDF file identifier.
name	Variable name.
xtype	NetCDF atomic type.
ndims	Number of dimensions.
dimidsp	Array of dimension ids.
varidp	Destination for the assigned variable id.

Returns

NC_NOERR on success, or a NetCDF error code.

NEXTCDF4_def_var_chunking()

int NEXTCDF4_def_var_chunking	(	int	ncid,
		int	varid,
		int	storage,
		const size_t *	chunksizesp
	)

Variable storage-property dispatch callbacks.

NEXTCDF4_def_var_deflate()

int NEXTCDF4_def_var_deflate	(	int	ncid,
		int	varid,
		int	shuffle,
		int	deflate,
		int	deflate_level
	)

NEXTCDF4_def_var_endian()

int NEXTCDF4_def_var_endian	(	int	ncid,
		int	varid,
		int	endianness
	)

NEXTCDF4_def_var_fill()

int NEXTCDF4_def_var_fill	(	int	ncid,
		int	varid,
		int	no_fill,
		const void *	fill_value
	)

NEXTCDF4_def_var_filter()

int NEXTCDF4_def_var_filter	(	int	ncid,
		int	varid,
		unsigned int	id,
		size_t	nparams,
		const unsigned int *	params
	)

NEXTCDF4_def_var_fletcher32()

int NEXTCDF4_def_var_fletcher32	(	int	ncid,
		int	varid,
		int	fletcher32
	)

NEXTCDF4_def_var_quantize()

int NEXTCDF4_def_var_quantize	(	int	ncid,
		int	varid,
		int	quantize_mode,
		int	nsd
	)

NEXTCDF4_del_att()

int NEXTCDF4_del_att	(	int	ncid,
		int	varid,
		const char *	name
	)

Delete an attribute.

Parameters

ncid	NetCDF file identifier.
varid	Variable id or NC_GLOBAL.
name	Attribute name.

Returns

NC_NOERR on success, or a NetCDF error code.

NEXTCDF4_get_att()

int NEXTCDF4_get_att	(	int	ncid,
		int	varid,
		const char *	name,
		void *	value,
		nc_type	memtype
	)

Get an attribute from the root group or a variable.

Parameters

ncid	NetCDF file identifier.
varid	Variable id or NC_GLOBAL.
name	Attribute name.
value	Destination buffer.
memtype	Requested in-memory type.

Returns

NC_NOERR on success, or a NetCDF error code.

NEXTCDF4_inq_dim()

int NEXTCDF4_inq_dim	(	int	ncid,
		int	dimid,
		char *	name,
		size_t *	lenp
	)

Inquire a dimension by id.

Parameters

ncid	NetCDF file identifier.
dimid	Dimension id.
name	Destination for the dimension name.
lenp	Destination for the dimension length.

Returns

NC_NOERR on success, or a NetCDF error code.

NEXTCDF4_inq_var()

int NEXTCDF4_inq_var	(	int	ncid,
		int	varid,
		char *	name,
		nc_type *	xtypep,
		int *	ndimsp,
		int *	dimidsp,
		int *	nattsp
	)

Inquire a variable by id.

Parameters

ncid	NetCDF file identifier.
varid	Variable id.
name	Destination for the variable name.
xtypep	Destination for the variable type.
ndimsp	Destination for the rank.
dimidsp	Destination for the dimension ids.
nattsp	Destination for the number of attributes.

Returns

NC_NOERR on success, or a NetCDF error code.

NEXTCDF4_inq_var_all()

int NEXTCDF4_inq_var_all	(	int	ncid,
		int	varid,
		char *	name,
		nc_type *	xtypep,
		int *	ndimsp,
		int *	dimidsp,
		int *	nattsp,
		int *	shufflep,
		int *	deflatep,
		int *	deflate_levelp,
		int *	fletcher32p,
		int *	contiguousp,
		size_t *	chunksizesp,
		int *	no_fillp,
		void *	fill_valuep,
		int *	endiannessp,
		unsigned int *	idp,
		size_t *	nparamsp,
		unsigned int *	params
	)

NEXTCDF4_inq_var_filter_ids()

int NEXTCDF4_inq_var_filter_ids	(	int	ncid,
		int	varid,
		size_t *	nfiltersp,
		unsigned int *	ids
	)

NEXTCDF4_inq_var_filter_info()

int NEXTCDF4_inq_var_filter_info	(	int	ncid,
		int	varid,
		unsigned int	id,
		size_t *	nparamsp,
		unsigned int *	params
	)

NEXTCDF4_load_metadata()

int NEXTCDF4_load_metadata	(	NEXTCDF4_FILE_INFO_T *	file,
		NC_FILE_INFO_T *	h5
	)

Load all root-group metadata from an open HDF5 file.

Parameters

file	Open NEXTCDF-4 state.
h5	Common NetCDF-4 file metadata.

Returns

NC_NOERR on success, or a NetCDF error code.

NEXTCDF4_map_hdf_type()

int NEXTCDF4_map_hdf_type	(	nc_type	xtype,
		hid_t *	typep
	)

Map a fixed-size NetCDF atomic type to its HDF5 datatype.

Parameters

xtype	NetCDF atomic type.
typep	Destination for an HDF5 datatype identifier.

Returns

NC_NOERR or NC_EBADTYPE.

NEXTCDF4_put_att()

int NEXTCDF4_put_att	(	int	ncid,
		int	varid,
		const char *	name,
		nc_type	xtype,
		size_t	len,
		const void *	value,
		nc_type	memtype
	)

Put an attribute on the root group or a variable.

Parameters

ncid	NetCDF file identifier.
varid	Variable id or NC_GLOBAL.
name	Attribute name.
xtype	NetCDF atomic type.
len	Number of elements.
value	Attribute data.
memtype	In-memory type for the attribute value.

Returns

NC_NOERR on success, or a NetCDF error code.

NEXTCDF4_rename_att()

int NEXTCDF4_rename_att	(	int	ncid,
		int	varid,
		const char *	name,
		const char *	newname
	)

Rename an attribute.

Parameters

ncid	NetCDF file identifier.
varid	Variable id or NC_GLOBAL.
name	Current attribute name.
newname	New attribute name.

Returns

NC_NOERR on success, or a NetCDF error code.

NEXTCDF4_rename_dim()

int NEXTCDF4_rename_dim	(	int	ncid,
		int	dimid,
		const char *	name
	)

Rename a dimension.

Parameters

ncid	NetCDF file identifier.
dimid	Dimension id.
name	New dimension name.

Returns

NC_NOERR on success, or a NetCDF error code.

NEXTCDF4_rename_var()

int NEXTCDF4_rename_var	(	int	ncid,
		int	varid,
		const char *	name
	)

Rename a variable.

Parameters

ncid	NetCDF file identifier.
varid	Variable id.
name	New variable name.

Returns

NC_NOERR on success, or a NetCDF error code.

NEXTCDF4_type_name()

const char * NEXTCDF4_type_name

(

nc_type

xtype

)

Return a display name for a fixed-size NetCDF atomic type.

Parameters

xtype

NetCDF atomic type.

Returns

A pointer to a constant string.

NEXTCDF4_type_size()

int NEXTCDF4_type_size	(	nc_type	xtype,
		size_t *	sizep
	)

Return the in-memory size of a fixed-size NetCDF atomic type.

Parameters

xtype	NetCDF atomic type.
sizep	Destination for the size in bytes.

Returns

NC_NOERR or NC_EBADTYPE.

read_hdf5_att()

static int read_hdf5_att ( hid_t  loc, const char *  name, NCindex *  list, NC_OBJ *  container  )

static

resolve_var_dimids()

static int resolve_var_dimids ( NC_GRP_INFO_T *  grp, hid_t  dset, int  ndims, int *  dimids  )

static

scale_resolve_visitor()

static int scale_resolve_visitor ( hid_t  did, unsigned int  dim, hid_t  dsid, void *  op_data  )

static

set_var_type()

static int set_var_type ( NC_VAR_INFO_T *  var, nc_type  xtype  )

static

write_int_array_att()

static int write_int_array_att ( hid_t  loc, const char *  name, const int *  values, size_t  len  )

static

write_int_att()

static int write_int_att ( hid_t  loc, const char *  name, int  value  )

static

write_string_att()

static int write_string_att ( hid_t  loc, const char *  name, const char *  value  )

static

Variable Documentation

reserved_atts

const char* reserved_atts[]

static

Initial value:

= {
    NEXTCDF4_BACKEND_ATT,
    NEXTCDF4_MODEL_ATT,
    NEXTCDF4_DIMID_ATT,
    NEXTCDF4_VARID_ATT,
    NEXTCDF4_VARDIMIDS_ATT,
    "CLASS",
    "NAME",
    "REFERENCE_LIST",
    "DIMENSION_LIST",
    "_Netcdf4Coordinates",
    "_FillValue",
    "_Format",
    "_nc3_strict",
    "_NCProperties",
    "_SuperblockVersion",
    "_IsNetcdf4",
    "_ARRAY_DIMENSIONS",
    "_Codecs",
    NULL
}