GRASS GIS 7 Programmer's Manual  7.9.dev(2021)-e5379bbd7
gsds.c File Reference

OGSF library - dataset loading and management (lower level functions) More...

#include <stdlib.h>
#include <string.h>
#include <grass/gis.h>
#include <grass/glocale.h>
#include <grass/ogsf.h>
Include dependency graph for gsds.c:

Go to the source code of this file.

Macros

#define LUCKY   33
 
#define BLOC   20
 
#define MAX_DS   100
 

Functions

int gsds_findh (const char *name, IFLAG *changes, IFLAG *types, int begin)
 Get handle to gsds. More...
 
int gsds_newh (const char *name)
 Get handle to gsds. More...
 
typbuffgsds_get_typbuff (int id, IFLAG change_flag)
 Get data buffer. More...
 
char * gsds_get_name (int id)
 Get name. More...
 
int gsds_free_datah (int id)
 Free allocated dataset. More...
 
int gsds_free_data_buff (int id, int typ)
 Free allocated buffer. More...
 
size_t free_data_buffs (dataset *ds, int typ)
 Free data buffer. More...
 
size_t gsds_alloc_typbuff (int id, int *dims, int ndims, int type)
 Allocates correct buffer according to type, keeps track of total mem. More...
 
int gsds_get_changed (int id)
 ADD. More...
 
int gsds_set_changed (int id, IFLAG reason)
 ADD. More...
 
int gsds_get_type (int id)
 ADD. More...
 

Detailed Description

OGSF library - dataset loading and management (lower level functions)

GRASS OpenGL gsurf OGSF Library

The idea here is to treat datasets as separate objects, which SHOULD:

  • allow easier reuse of data for different attributes.
  • allow a mechanism for changing data and have changes reflected in each attribute using that data.
  • allow a mechanism to automatically update data when the data source is changed.
  • allow easier weaning from GRASS.
  • allow easier use of shared memory between processes.

These structures are defined in gstypes.h:

typedef struct{ float *fb; int *ib; short *sb; char *cb; struct BM *bm; } typbuff;

How about adding a transform func here, so GET_MAPATT would do an on-the-fly transformation? Or even a transform func LIST!

typedef struct{ int data_id; int dims[MAXDIMS]; int ndims; int numbytes; char unique_name[80]; typbuff databuff; int changed; int need_reload; } dataset;

(C) 1999-2008 by the GRASS Development Team

This program is free software under the GNU General Public License (>=v2). Read the file COPYING that comes with GRASS for details.

Author
Bill Brown UI GMS Lab
Doxygenized by Martin Landa <landa.martin gmail.com> (May 2008)

Definition in file gsds.c.

Macro Definition Documentation

◆ BLOC

#define BLOC   20

Definition at line 64 of file gsds.c.

◆ LUCKY

#define LUCKY   33

Definition at line 63 of file gsds.c.

◆ MAX_DS

#define MAX_DS   100

Definition at line 65 of file gsds.c.

Function Documentation

◆ free_data_buffs()

size_t free_data_buffs ( dataset ds,
int  typ 
)

Free data buffer.

Parameters
dspointer to dataset struct
typdata type
Returns
freed size

Definition at line 393 of file gsds.c.

References ATTY_CHAR, ATTY_FLOAT, ATTY_INT, ATTY_MASK, ATTY_NULL, ATTY_SHORT, typbuff::bm, BM_destroy(), BM_get_map_size(), typbuff::cb, dataset::databuff, dataset::dims, typbuff::fb, free(), typbuff::ib, dataset::ndims, typbuff::nm, NULL, and typbuff::sb.

◆ gsds_alloc_typbuff()

size_t gsds_alloc_typbuff ( int  id,
int *  dims,
int  ndims,
int  type 
)

Allocates correct buffer according to type, keeps track of total mem.

Todo:
add ATTY_CONST
Parameters
iddataset id
dimsarray of dimensions
ndimsnumber of dimensions
typedata type
Returns
amount of allocated memory

Definition at line 482 of file gsds.c.

◆ gsds_findh()

int gsds_findh ( const char *  name,
IFLAG changes,
IFLAG types,
int  begin 
)

Get handle to gsds.

Successive calls will continue search until "begin" is set (problem here is, unique_name no longer uniquely identifies dataset, since changes may be made; but unique_name should still be useful for reloading dataset) changes & types are set to actual for dataset if found.

Parameters
name
changes,typesacceptable changes & types, flags may be or'd not changed is assumed to always be acceptable
beginflag to indicate search from beginning
Returns
data id
-1 not found

Definition at line 188 of file gsds.c.

◆ gsds_free_data_buff()

int gsds_free_data_buff ( int  id,
int  typ 
)

Free allocated buffer.

Parameters
iddataset id
typdata type
Returns
0 not found
1 found

Definition at line 369 of file gsds.c.

◆ gsds_free_datah()

int gsds_free_datah ( int  id)

Free allocated dataset.

Parameters
id
Returns
0 not found
1 found

Definition at line 329 of file gsds.c.

References G_debug().

◆ gsds_get_changed()

int gsds_get_changed ( int  id)

ADD.

Parameters
id
Returns
-1 on error

Definition at line 615 of file gsds.c.

Referenced by Gs_update_attrange().

◆ gsds_get_name()

char* gsds_get_name ( int  id)

Get name.

Parameters
id
Returns
name
NULL on failure

Definition at line 303 of file gsds.c.

References GPATH_MAX.

Referenced by GS_get_cat_at_xy().

◆ gsds_get_typbuff()

typbuff* gsds_get_typbuff ( int  id,
IFLAG  change_flag 
)

Get data buffer.

Doesn't prevent writing a buff thats's been gotten with change_flag == 0 (could return a copy, but willing to trust calling func for now)

Parameters
iddataset id
change_flagset changed flag
Returns
pointer to typbuff struct
NULL on failure

Definition at line 281 of file gsds.c.

Referenced by gs_get_att_typbuff(), and Gs_update_attrange().

◆ gsds_get_type()

int gsds_get_type ( int  id)

ADD.

Parameters
id
Returns

Definition at line 653 of file gsds.c.

◆ gsds_newh()

int gsds_newh ( const char *  name)

Get handle to gsds.

Parameters
nameraster map name
Returns
-1 on failure
data id

Definition at line 219 of file gsds.c.

◆ gsds_set_changed()

int gsds_set_changed ( int  id,
IFLAG  reason 
)

ADD.

Parameters
id
reason
Returns
-1 on error

Definition at line 635 of file gsds.c.