netcdf-c/libdispatch/dvlen.c

/*! \file
  Functions for VLEN Types

  Copyright 2018 University Corporation for Atmospheric
  Research/Unidata. See \ref copyright file for more info. */

#include "ncdispatch.h"

/** \name Variable Length Array Types

    Functions to create and learn about VLEN types. */
/*! \{ */ /* All these functions are part of this named group... */

/** 
\ingroup user_types 
Free an array of vlens given the number of elements and an array. 

When you read an array of VLEN typed instances, the library will allocate
the storage space for the data in each VLEN in the array (but not the array itself).
That VLEN data must be freed eventually, so pass the pointer to the array plus
the number of elements in the array to this function when you're done with
the data, and it will free the all the VLEN instances.
The caller is still responsible for free'ing the array itself,
if it was dynamically allocated.

WARNING: this function only works if the basetype of the vlen type
is fixed size. This means it is an atomic type except NC_STRING,
or an NC_ENUM, or and NC_OPAQUE, or an NC_COMPOUND where all
the fields of the compound type are themselves fixed size.

If you have a more complex VLEN base-type, then it is better to call
the "nc_reclaim_data" function.

\param nelems number of elements in the array.
\param vlens pointer to the vlen object.

\returns ::NC_NOERR No error.
*/ 
int
nc_free_vlens(size_t nelems, nc_vlen_t vlens[])
{
   int ret;
   size_t i;

   for(i = 0; i < nelems; i++) 
      if ((ret = nc_free_vlen(&vlens[i])))
	 return ret;

   return NC_NOERR;
}

/** 
\ingroup user_types 
Free memory in a single VLEN object. 
This function is equivalent to calling *nc_free_vlens* with nelems == 1.

\param vl pointer to the vlen object.
\returns ::NC_NOERR No error.
*/
int
nc_free_vlen(nc_vlen_t *vl)
{
   free(vl->p);
   return NC_NOERR;
}

/** 
\ingroup user_types
Use this function to define a variable length array type.

\param ncid \ref ncid
\param name \ref object_name of new type.

\param base_typeid The typeid of the base type of the VLEN. For
example, for a VLEN of shorts, the base type is ::NC_SHORT. This can be
a user defined type.

\param xtypep A pointer to an nc_type variable. The typeid of the new
VLEN type will be set here.

\returns ::NC_NOERR No error.
\returns ::NC_EBADID Bad \ref ncid.
\returns ::NC_EBADTYPE Bad type id.
\returns ::NC_ENOTNC4 Not an netCDF-4 file, or classic model enabled.
\returns ::NC_EHDFERR An error was reported by the HDF5 layer.
\returns ::NC_ENAMEINUSE That name is in use.
\returns ::NC_EMAXNAME Name exceeds max length NC_MAX_NAME.
\returns ::NC_EBADNAME Name contains illegal characters.
\returns ::NC_EPERM Attempt to write to a read-only file.
\returns ::NC_ENOTINDEFINE Not in define mode. 
 */
int
nc_def_vlen(int ncid, const char *name, nc_type base_typeid, nc_type *xtypep)
{
    NC* ncp;
    int stat = NC_check_id(ncid,&ncp);
    if(stat != NC_NOERR) return stat;
    return ncp->dispatch->def_vlen(ncid,name,base_typeid,xtypep);
}

/** \ingroup user_types
Learn about a VLEN type.

\param ncid \ref ncid
\param xtype The type of the VLEN to inquire about. 
\param name \ref object_name of the type. \ref ignored_if_null.

\param datum_sizep A pointer to a size_t, this will get the size of
one element of this vlen. \ref ignored_if_null.

\param base_nc_typep Pointer to get the base type of the VLEN. \ref
ignored_if_null.

\returns ::NC_NOERR No error.
\returns ::NC_EBADID Bad \ref ncid.
\returns ::NC_EBADTYPE Bad type id.
\returns ::NC_ENOTNC4 Not an netCDF-4 file, or classic model enabled.
\returns ::NC_EHDFERR An error was reported by the HDF5 layer.
 */
int
nc_inq_vlen(int ncid, nc_type xtype, char *name, size_t *datum_sizep, nc_type *base_nc_typep)
{
    int class = 0;
    int stat = nc_inq_user_type(ncid,xtype,name,datum_sizep,base_nc_typep,NULL,&class);
    if(stat != NC_NOERR) return stat;
    if(class != NC_VLEN) stat = NC_EBADTYPE;
    return stat;
}
/*! \} */  /* End of named group ...*/

/** \internal
\ingroup user_types

Put a VLEN element. This function writes an element of a VLEN for the
Fortran APIs.

\param ncid \ref ncid
\param typeid1 Typeid of the VLEN.
\param vlen_element Pointer to the element of the VLEN.
\param len Length of the VLEN element.
\param data VLEN data.

\returns ::NC_NOERR No error.
\returns ::NC_EBADID Bad \ref ncid.
\returns ::NC_EBADTYPE Bad type id.
\returns ::NC_ENOTNC4 Not an netCDF-4 file, or classic model enabled.
\returns ::NC_EHDFERR An error was reported by the HDF5 layer.
\returns ::NC_EPERM Attempt to write to a read-only file.
 */
int
nc_put_vlen_element(int ncid, int typeid1, void *vlen_element, size_t len, const void *data)
{
    NC* ncp;
    int stat = NC_check_id(ncid,&ncp);
    if(stat != NC_NOERR) return stat;
    return ncp->dispatch->put_vlen_element(ncid,typeid1,vlen_element,len,data);
}

/** 
\internal
\ingroup user_types

Get a VLEN element. This function reads an element of a VLEN for the
Fortran APIs.

\param ncid \ref ncid
\param typeid1 Typeid of the VLEN.
\param vlen_element Pointer to the element of the VLEN.
\param len Length of the VLEN element.
\param data VLEN data.

\returns ::NC_NOERR No error.
\returns ::NC_EBADID Bad \ref ncid.
\returns ::NC_EBADTYPE Bad type id.
\returns ::NC_ENOTNC4 Not an netCDF-4 file, or classic model enabled.
\returns ::NC_EHDFERR An error was reported by the HDF5 layer.
 */
int
nc_get_vlen_element(int ncid, int typeid1, const void *vlen_element, 
		    size_t *len, void *data)
{
    NC *ncp;
    int stat = NC_check_id(ncid,&ncp);
    if(stat != NC_NOERR) return stat;
    return ncp->dispatch->get_vlen_element(ncid, typeid1, vlen_element, 
					   len, data);
}