summaryrefslogtreecommitdiffstats
path: root/src/H5R.c
blob: a2b310c6f295853a6c5a83bd35ea6af725a29abf (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
 * Copyright by The HDF Group.                                               *
 * Copyright by the Board of Trustees of the University of Illinois.         *
 * All rights reserved.                                                      *
 *                                                                           *
 * This file is part of HDF5.  The full HDF5 copyright notice, including     *
 * terms governing use, modification, and redistribution, is contained in    *
 * the files COPYING and Copyright.html.  COPYING can be found at the root   *
 * of the source code distribution tree; Copyright.html can be found at the  *
 * root level of an installed copy of the electronic HDF5 document set and   *
 * is linked from the top-level documents page.  It can also be found at     *
 * http://hdfgroup.org/HDF5/doc/Copyright.html.  If you do not have          *
 * access to either file, you may request a copy from help@hdfgroup.org.     *
 * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */

/****************/
/* Module Setup */
/****************/

#define H5R_PACKAGE		/*suppress error about including H5Rpkg   */

/* Interface initialization */
#define H5_INTERFACE_INIT_FUNC	H5R_init_interface


/***********/
/* Headers */
/***********/
#include "H5private.h"		/* Generic Functions			*/
#include "H5ACprivate.h"        /* Metadata cache                       */
#include "H5Dprivate.h"		/* Datasets				*/
#include "H5Eprivate.h"		/* Error handling		  	*/
#include "H5Gprivate.h"		/* Groups				*/
#include "H5HGprivate.h"	/* Global Heaps				*/
#include "H5Iprivate.h"		/* IDs			  		*/
#include "H5MMprivate.h"	/* Memory management			*/
#include "H5Rpkg.h"		/* References				*/
#include "H5Sprivate.h"		/* Dataspaces 				*/


/****************/
/* Local Macros */
/****************/


/******************/
/* Local Typedefs */
/******************/


/********************/
/* Local Prototypes */
/********************/

static herr_t H5R_create(void *ref, H5G_loc_t *loc, const char *name,
        H5R_type_t ref_type, H5S_t *space, hid_t dxpl_id);
static hid_t H5R_dereference(H5F_t *file, hid_t dxpl_id, H5R_type_t ref_type,
    const void *_ref, hbool_t app_ref);
static H5S_t * H5R_get_region(H5F_t *file, hid_t dxpl_id, const void *_ref);
static ssize_t H5R_get_name(H5F_t *file, hid_t lapl_id, hid_t dxpl_id, hid_t id,
    H5R_type_t ref_type, const void *_ref, char *name, size_t size);


/*********************/
/* Package Variables */
/*********************/


/*****************************/
/* Library Private Variables */
/*****************************/


/*******************/
/* Local Variables */
/*******************/

/* Reference ID class */
static const H5I_class_t H5I_REFERENCE_CLS[1] = {{
    H5I_REFERENCE,		/* ID class value */
    H5I_CLASS_REUSE_IDS,	/* Class flags */
    0,				/* # of reserved IDs for class */
    NULL			/* Callback routine for closing objects of this class */
}};



/*-------------------------------------------------------------------------
 * Function:	H5R_init
 *
 * Purpose:	Initialize the interface from some other package.
 *
 * Return:	Success:	non-negative
 *		Failure:	negative
 *
 * Programmer:	Quincey Koziol
 *              Thursday, September 13, 2007
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5R_init(void)
{
    herr_t ret_value = SUCCEED;   /* Return value */

    FUNC_ENTER_NOAPI(FAIL)
    /* FUNC_ENTER() does all the work */

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5R_init() */


/*--------------------------------------------------------------------------
NAME
   H5R_init_interface -- Initialize interface-specific information
USAGE
    herr_t H5R_init_interface()

RETURNS
    Non-negative on success/Negative on failure
DESCRIPTION
    Initializes any interface-specific data or routines.

--------------------------------------------------------------------------*/
static herr_t
H5R_init_interface(void)
{
    herr_t      ret_value=SUCCEED;       /* Return value */

    FUNC_ENTER_NOAPI_NOINIT

    /* Initialize the atom group for the file IDs */
    if(H5I_register_type(H5I_REFERENCE_CLS) < 0)
	HGOTO_ERROR(H5E_REFERENCE, H5E_CANTINIT, FAIL, "unable to initialize interface");

done:
    FUNC_LEAVE_NOAPI(ret_value)
}


/*--------------------------------------------------------------------------
 NAME
    H5R_term_interface
 PURPOSE
    Terminate various H5R objects
 USAGE
    void H5R_term_interface()
 RETURNS
    void
 DESCRIPTION
    Release the atom group and any other resources allocated.
 GLOBAL VARIABLES
 COMMENTS, BUGS, ASSUMPTIONS
     Can't report errors...
 EXAMPLES
 REVISION LOG
--------------------------------------------------------------------------*/
int
H5R_term_interface(void)
{
    int	n = 0;

    FUNC_ENTER_NOAPI_NOINIT_NOERR

    if (H5_interface_initialize_g) {
	if(H5I_nmembers(H5I_REFERENCE) > 0) {
	    (void)H5I_clear_type(H5I_REFERENCE, FALSE, FALSE);
            n++; /*H5I*/
	} /* end if */
        else {
            /* Close deprecated interface */
            n += H5R__term_deprec_interface();

            /* Destroy the reference id group */
	    (void)H5I_dec_type_ref(H5I_REFERENCE);
            n++; /*H5I*/

            /* Mark closed */
	    H5_interface_initialize_g = 0;
	} /* end else */
    } /* end if */

    FUNC_LEAVE_NOAPI(n)
} /* end H5R_term_interface() */


/*--------------------------------------------------------------------------
 NAME
    H5R_create
 PURPOSE
    Creates a particular kind of reference for the user
 USAGE
    herr_t H5R_create(ref, loc, name, ref_type, space)
        void *ref;          OUT: Reference created
        H5G_loc_t *loc;     IN: File location used to locate object pointed to
        const char *name;   IN: Name of object at location LOC_ID of object
                                    pointed to
        H5R_type_t ref_type;    IN: Type of reference to create
        H5S_t *space;       IN: Dataspace ID with selection, used for Dataset
                                    Region references.

 RETURNS
    Non-negative on success/Negative on failure
 DESCRIPTION
    Creates a particular type of reference specified with REF_TYPE, in the
    space pointed to by REF.  The LOC_ID and NAME are used to locate the object
    pointed to and the SPACE_ID is used to choose the region pointed to (for
    Dataset Region references).
 GLOBAL VARIABLES
 COMMENTS, BUGS, ASSUMPTIONS
 EXAMPLES
 REVISION LOG
--------------------------------------------------------------------------*/
static herr_t
H5R_create(void *_ref, H5G_loc_t *loc, const char *name, H5R_type_t ref_type, H5S_t *space, hid_t dxpl_id)
{
    H5G_loc_t	obj_loc;		/* Group hier. location of object */
    H5G_name_t  path;            	/* Object group hier. path */
    H5O_loc_t   oloc;            	/* Object object location */
    hbool_t     obj_found = FALSE;      /* Object location found */
    herr_t ret_value = SUCCEED;         /* Return value */

    FUNC_ENTER_NOAPI_NOINIT

    HDassert(_ref);
    HDassert(loc);
    HDassert(name);
    HDassert(ref_type > H5R_BADTYPE && ref_type < H5R_MAXTYPE);

    /* Set up object location to fill in */
    obj_loc.oloc = &oloc;
    obj_loc.path = &path;
    H5G_loc_reset(&obj_loc);

    /* Find the object */
    if(H5G_loc_find(loc, name, &obj_loc, H5P_DEFAULT, dxpl_id) < 0)
        HGOTO_ERROR(H5E_REFERENCE, H5E_NOTFOUND, FAIL, "object not found")
    obj_found = TRUE;

    switch(ref_type) {
        case H5R_OBJECT:
        {
            hobj_ref_t *ref = (hobj_ref_t *)_ref; /* Get pointer to correct type of reference struct */

            *ref = obj_loc.oloc->addr;
            break;
        }

        case H5R_DATASET_REGION:
        {
            H5HG_t hobjid;      /* Heap object ID */
            hdset_reg_ref_t *ref = (hdset_reg_ref_t *)_ref; /* Get pointer to correct type of reference struct */
            hssize_t buf_size;  /* Size of buffer needed to serialize selection */
            uint8_t *p;       /* Pointer to OID to store */
            uint8_t *buf;     /* Buffer to store serialized selection in */
            unsigned heapid_found;  /* Flag for non-zero heap ID found */
            unsigned u;        /* local index */

            /* Set up information for dataset region */

            /* Return any previous heap block to the free list if we are garbage collecting */
            if(H5F_GC_REF(loc->oloc->file)) {
                /* Check for an existing heap ID in the reference */
                for(u = 0, heapid_found = 0, p = (uint8_t *)ref; u < H5R_DSET_REG_REF_BUF_SIZE; u++)
                    if(p[u] != 0) {
                        heapid_found = 1;
                        break;
                    } /* end if */

                if(heapid_found != 0) {
/* Return heap block to free list */
                } /* end if */
            } /* end if */

            /* Zero the heap ID out, may leak heap space if user is re-using reference and doesn't have garbage collection on */
            HDmemset(ref, 0, H5R_DSET_REG_REF_BUF_SIZE);

            /* Get the amount of space required to serialize the selection */
            if((buf_size = H5S_SELECT_SERIAL_SIZE(space)) < 0)
                HGOTO_ERROR(H5E_REFERENCE, H5E_CANTINIT, FAIL, "Invalid amount of space for serializing selection")

            /* Increase buffer size to allow for the dataset OID */
            buf_size += (hssize_t)sizeof(haddr_t);

            /* Allocate the space to store the serialized information */
            H5_CHECK_OVERFLOW(buf_size, hssize_t, size_t);
            if(NULL == (buf = (uint8_t *)H5MM_malloc((size_t)buf_size)))
                HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL, "memory allocation failed")

            /* Serialize information for dataset OID into heap buffer */
            p = (uint8_t *)buf;
            H5F_addr_encode(loc->oloc->file, &p, obj_loc.oloc->addr);

            /* Serialize the selection into heap buffer */
            if(H5S_SELECT_SERIALIZE(space, p) < 0)
                HGOTO_ERROR(H5E_REFERENCE, H5E_CANTCOPY, FAIL, "Unable to serialize selection")

            /* Save the serialized buffer for later */
            H5_CHECK_OVERFLOW(buf_size, hssize_t, size_t);
            if(H5HG_insert(loc->oloc->file, dxpl_id, (size_t)buf_size, buf, &hobjid) < 0)
                HGOTO_ERROR(H5E_REFERENCE, H5E_WRITEERROR, FAIL, "Unable to serialize selection")

            /* Serialize the heap ID and index for storage in the file */
            p = (uint8_t *)ref;
            H5F_addr_encode(loc->oloc->file, &p, hobjid.addr);
            UINT32ENCODE(p, hobjid.idx);

            /* Free the buffer we serialized data in */
            H5MM_xfree(buf);
            break;
        }

        case H5R_BADTYPE:
        case H5R_MAXTYPE:
        default:
            HDassert("unknown reference type" && 0);
            HGOTO_ERROR(H5E_REFERENCE, H5E_UNSUPPORTED, FAIL, "internal error (unknown reference type)")
    } /* end switch */

done:
    if(obj_found)
        H5G_loc_free(&obj_loc);

    FUNC_LEAVE_NOAPI(ret_value)
}   /* end H5R_create() */


/*--------------------------------------------------------------------------
 NAME
    H5Rcreate
 PURPOSE
    Creates a particular kind of reference for the user
 USAGE
    herr_t H5Rcreate(ref, loc_id, name, ref_type, space_id)
        void *ref;          OUT: Reference created
        hid_t loc_id;       IN: Location ID used to locate object pointed to
        const char *name;   IN: Name of object at location LOC_ID of object
                                    pointed to
        H5R_type_t ref_type;    IN: Type of reference to create
        hid_t space_id;     IN: Dataspace ID with selection, used for Dataset
                                    Region references.

 RETURNS
    Non-negative on success/Negative on failure
 DESCRIPTION
    Creates a particular type of reference specified with REF_TYPE, in the
    space pointed to by REF.  The LOC_ID and NAME are used to locate the object
    pointed to and the SPACE_ID is used to choose the region pointed to (for
    Dataset Region references).
 GLOBAL VARIABLES
 COMMENTS, BUGS, ASSUMPTIONS
 EXAMPLES
 REVISION LOG
--------------------------------------------------------------------------*/
herr_t
H5Rcreate(void *ref, hid_t loc_id, const char *name, H5R_type_t ref_type, hid_t space_id)
{
    H5G_loc_t   loc;            /* File location */
    H5S_t      *space = NULL;   /* Pointer to dataspace containing region */
    herr_t      ret_value;      /* Return value */

    FUNC_ENTER_API(FAIL)
    H5TRACE5("e", "*xi*sRti", ref, loc_id, name, ref_type, space_id);

    /* Check args */
    if(ref == NULL)
        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid reference pointer")
    if(H5G_loc(loc_id, &loc) < 0)
        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a location")
    if(!name || !*name)
        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no name given")
    if(ref_type <= H5R_BADTYPE || ref_type >= H5R_MAXTYPE)
        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid reference type")
    if(ref_type != H5R_OBJECT && ref_type != H5R_DATASET_REGION)
        HGOTO_ERROR(H5E_ARGS, H5E_UNSUPPORTED, FAIL, "reference type not supported")
    if(space_id == (-1) && ref_type == H5R_DATASET_REGION)
        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "reference region dataspace id must be valid")
    if(space_id != (-1) && (NULL == (space = (H5S_t *)H5I_object_verify(space_id, H5I_DATASPACE))))
        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a dataspace")

    /* Create reference */
    if((ret_value = H5R_create(ref, &loc, name, ref_type, space, H5AC_dxpl_id)) < 0)
        HGOTO_ERROR(H5E_REFERENCE, H5E_CANTINIT, FAIL, "unable to create reference")

done:
    FUNC_LEAVE_API(ret_value)
}   /* end H5Rcreate() */


/*--------------------------------------------------------------------------
 NAME
    H5R_dereference
 PURPOSE
    Opens the HDF5 object referenced.
 USAGE
    hid_t H5R_dereference(ref)
        H5F_t *file;        IN: File the object being dereferenced is within
        H5R_type_t ref_type;    IN: Type of reference
        void *ref;          IN: Reference to open.

 RETURNS
    Valid ID on success, Negative on failure
 DESCRIPTION
    Given a reference to some object, open that object and return an ID for
    that object.
 GLOBAL VARIABLES
 COMMENTS, BUGS, ASSUMPTIONS
    Currently only set up to work with references to datasets
 EXAMPLES
 REVISION LOG

    M. Scot Breitenfeld
    3 March 2015
    Added a check for undefined reference pointer.
--------------------------------------------------------------------------*/
static hid_t
H5R_dereference(H5F_t *file, hid_t dxpl_id, H5R_type_t ref_type, const void *_ref, hbool_t app_ref)
{
    H5O_loc_t oloc;             /* Object location */
    H5G_name_t path;            /* Path of object */
    H5G_loc_t loc;              /* Group location */
    unsigned rc;		/* Reference count of object */
    H5O_type_t obj_type;        /* Type of object */
    hid_t ret_value;            /* Return value */

    FUNC_ENTER_NOAPI_NOINIT

    HDassert(_ref);
    HDassert(ref_type > H5R_BADTYPE && ref_type < H5R_MAXTYPE);
    HDassert(file);

    /* Initialize the object location */
    H5O_loc_reset(&oloc);
    oloc.file = file;

    switch(ref_type) {
        case H5R_OBJECT:
            oloc.addr = *(const hobj_ref_t *)_ref; /* Only object references currently supported */
	    if(!H5F_addr_defined(oloc.addr) || oloc.addr == 0)
	      HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "Undefined reference pointer")
	      break;
            
        case H5R_DATASET_REGION:
        {
            H5HG_t hobjid;  /* Heap object ID */
            uint8_t *buf;   /* Buffer to store serialized selection in */
            const uint8_t *p;           /* Pointer to OID to store */

            /* Get the heap ID for the dataset region */
            p = (const uint8_t *)_ref;
            H5F_addr_decode(oloc.file, &p, &(hobjid.addr));
            UINT32DECODE(p, hobjid.idx);

            if(!H5F_addr_defined(hobjid.addr) || hobjid.addr == 0)
	      HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "Undefined reference pointer")

            /* Get the dataset region from the heap (allocate inside routine) */
            if(NULL == (buf = (uint8_t *)H5HG_read(oloc.file, dxpl_id, &hobjid, NULL, NULL)))
                HGOTO_ERROR(H5E_REFERENCE, H5E_READERROR, FAIL, "Unable to read dataset region information")

            /* Get the object oid for the dataset */
            p = buf;
            H5F_addr_decode(oloc.file, &p, &(oloc.addr));

            /* Free the buffer allocated in H5HG_read() */
            H5MM_xfree(buf);
        } /* end case */
        break;

        case H5R_BADTYPE:
        case H5R_MAXTYPE:
        default:
            HDassert("unknown reference type" && 0);
            HGOTO_ERROR(H5E_REFERENCE, H5E_UNSUPPORTED, FAIL, "internal error (unknown reference type)")
    } /* end switch */

    /* Get the # of links for object, and its type */
    /* (To check to make certain that this object hasn't been deleted since the reference was created) */
    if(H5O_get_rc_and_type(&oloc, dxpl_id, &rc, &obj_type) < 0 || 0 == rc)
        HGOTO_ERROR(H5E_REFERENCE, H5E_LINKCOUNT, FAIL, "dereferencing deleted object")

    /* Construct a group location for opening the object */
    H5G_name_reset(&path);
    loc.oloc = &oloc;
    loc.path = &path;

    /* Open the object */
    switch(obj_type) {
        case H5O_TYPE_GROUP:
            {
                H5G_t *group;               /* Pointer to group to open */

                if(NULL == (group = H5G_open(&loc, dxpl_id)))
                    HGOTO_ERROR(H5E_SYM, H5E_NOTFOUND, FAIL, "not found")

                /* Create an atom for the group */
                if((ret_value = H5I_register(H5I_GROUP, group, app_ref)) < 0) {
                    H5G_close(group);
                    HGOTO_ERROR(H5E_SYM, H5E_CANTREGISTER, FAIL, "can't register group")
                } /* end if */
            } /* end case */
            break;

        case H5O_TYPE_NAMED_DATATYPE:
            {
                H5T_t *type;                /* Pointer to datatype to open */

                if(NULL == (type = H5T_open(&loc, dxpl_id)))
                    HGOTO_ERROR(H5E_DATATYPE, H5E_NOTFOUND, FAIL, "not found")

                /* Create an atom for the datatype */
                if((ret_value = H5I_register(H5I_DATATYPE, type, app_ref)) < 0) {
                    H5T_close(type);
                    HGOTO_ERROR(H5E_DATATYPE, H5E_CANTREGISTER, FAIL, "can't register datatype")
                } /* end if */
            } /* end case */
            break;

        case H5O_TYPE_DATASET:
            {
                hid_t dapl_id = H5P_DATASET_ACCESS_DEFAULT; /* dapl to use to open dataset */
                H5D_t *dset;                /* Pointer to dataset to open */

                /* Open the dataset */
                if(NULL == (dset = H5D_open(&loc, dapl_id, dxpl_id)))
                    HGOTO_ERROR(H5E_DATASET, H5E_NOTFOUND, FAIL, "not found")

                /* Create an atom for the dataset */
                if((ret_value = H5I_register(H5I_DATASET, dset, app_ref)) < 0) {
                    H5D_close(dset);
                    HGOTO_ERROR(H5E_DATASET, H5E_CANTREGISTER, FAIL, "can't register dataset")
                } /* end if */
            } /* end case */
            break;

        case H5O_TYPE_UNKNOWN:
        case H5O_TYPE_NTYPES:
        default:
            HGOTO_ERROR(H5E_REFERENCE, H5E_BADTYPE, FAIL, "can't identify type of object referenced")
     } /* end switch */

done:
    FUNC_LEAVE_NOAPI(ret_value)
}   /* end H5R_dereference() */


/*--------------------------------------------------------------------------
 NAME
    H5Rdereference
 PURPOSE
    Opens the HDF5 object referenced.
 USAGE
    hid_t H5Rdereference(ref)
        hid_t id;       IN: Dataset reference object is in or location ID of
                            object that the dataset is located within.
        H5R_type_t ref_type;    IN: Type of reference to create
        void *ref;      IN: Reference to open.

 RETURNS
    Valid ID on success, Negative on failure
 DESCRIPTION
    Given a reference to some object, open that object and return an ID for
    that object.
 GLOBAL VARIABLES
 COMMENTS, BUGS, ASSUMPTIONS
 EXAMPLES
 REVISION LOG
--------------------------------------------------------------------------*/
hid_t
H5Rdereference(hid_t id, H5R_type_t ref_type, const void *_ref)
{
    H5G_loc_t loc;      /* Group location */
    H5F_t *file = NULL; /* File object */
    hid_t ret_value;

    FUNC_ENTER_API(FAIL)
    H5TRACE3("i", "iRt*x", id, ref_type, _ref);

    /* Check args */
    if(H5G_loc(id, &loc) < 0)
        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a location")
    if(ref_type <= H5R_BADTYPE || ref_type >= H5R_MAXTYPE)
        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid reference type")
    if(_ref == NULL)
        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid reference pointer")

    /* Get the file pointer from the entry */
    file = loc.oloc->file;

    /* Create reference */
    if((ret_value = H5R_dereference(file, H5AC_ind_dxpl_id, ref_type, _ref, TRUE)) < 0)
        HGOTO_ERROR(H5E_REFERENCE, H5E_CANTINIT, FAIL, "unable to dereference object")

done:
    FUNC_LEAVE_API(ret_value)
}   /* end H5Rdereference() */


/*--------------------------------------------------------------------------
 NAME
    H5R_get_region
 PURPOSE
    Retrieves a dataspace with the region pointed to selected.
 USAGE
    H5S_t *H5R_get_region(file, ref_type, ref)
        H5F_t *file;        IN: File the object being dereferenced is within
        void *ref;          IN: Reference to open.

 RETURNS
    Pointer to the dataspace on success, NULL on failure
 DESCRIPTION
    Given a reference to some object, creates a copy of the dataset pointed
    to's dataspace and defines a selection in the copy which is the region
    pointed to.
 GLOBAL VARIABLES
 COMMENTS, BUGS, ASSUMPTIONS
 EXAMPLES
 REVISION LOG
--------------------------------------------------------------------------*/
static H5S_t *
H5R_get_region(H5F_t *file, hid_t dxpl_id, const void *_ref)
{
    H5O_loc_t oloc;             /* Object location */
    const uint8_t *p;           /* Pointer to OID to store */
    H5HG_t hobjid;              /* Heap object ID */
    uint8_t *buf = NULL;        /* Buffer to store serialized selection in */
    H5S_t *ret_value;

    FUNC_ENTER_NOAPI_NOINIT

    HDassert(_ref);
    HDassert(file);

    /* Initialize the object location */
    H5O_loc_reset(&oloc);
    oloc.file = file;

    /* Get the heap ID for the dataset region */
    p = (const uint8_t *)_ref;
    H5F_addr_decode(oloc.file, &p, &(hobjid.addr));
    UINT32DECODE(p, hobjid.idx);

    /* Get the dataset region from the heap (allocate inside routine) */
    if((buf = (uint8_t *)H5HG_read(oloc.file, dxpl_id, &hobjid, NULL, NULL)) == NULL)
        HGOTO_ERROR(H5E_REFERENCE, H5E_READERROR, NULL, "Unable to read dataset region information")

    /* Get the object oid for the dataset */
    p = buf;
    H5F_addr_decode(oloc.file, &p, &(oloc.addr));

    /* Open and copy the dataset's dataspace */
    if((ret_value = H5S_read(&oloc, dxpl_id)) == NULL)
        HGOTO_ERROR(H5E_DATASPACE, H5E_NOTFOUND, NULL, "not found")

    /* Unserialize the selection */
    if(H5S_select_deserialize(ret_value, p) < 0)
        HGOTO_ERROR(H5E_REFERENCE, H5E_CANTDECODE, NULL, "can't deserialize selection")

done:
    /* Free the buffer allocated in H5HG_read() */
    if(buf)
        H5MM_xfree(buf);

    FUNC_LEAVE_NOAPI(ret_value)
}   /* end H5R_get_region() */


/*--------------------------------------------------------------------------
 NAME
    H5Rget_region
 PURPOSE
    Retrieves a dataspace with the region pointed to selected.
 USAGE
    hid_t H5Rget_region(id, ref_type, ref)
        hid_t id;       IN: Dataset reference object is in or location ID of
                            object that the dataset is located within.
        H5R_type_t ref_type;    IN: Type of reference to get region of
        void *ref;        IN: Reference to open.

 RETURNS
    Valid ID on success, Negative on failure
 DESCRIPTION
    Given a reference to some object, creates a copy of the dataset pointed
    to's dataspace and defines a selection in the copy which is the region
    pointed to.
 GLOBAL VARIABLES
 COMMENTS, BUGS, ASSUMPTIONS
 EXAMPLES
 REVISION LOG
--------------------------------------------------------------------------*/
hid_t
H5Rget_region(hid_t id, H5R_type_t ref_type, const void *ref)
{
    H5G_loc_t loc;          /* Object's group location */
    H5S_t *space = NULL;    /* Dataspace object */
    hid_t ret_value;

    FUNC_ENTER_API(FAIL)
    H5TRACE3("i", "iRt*x", id, ref_type, ref);

    /* Check args */
    if(H5G_loc(id, &loc) < 0)
        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a location")
    if(ref_type != H5R_DATASET_REGION)
        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid reference type")
    if(ref == NULL)
        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid reference pointer")

    /* Get the dataspace with the correct region selected */
    if((space = H5R_get_region(loc.oloc->file, H5AC_ind_dxpl_id, ref)) == NULL)
        HGOTO_ERROR(H5E_REFERENCE, H5E_CANTCREATE, FAIL, "unable to create dataspace")

    /* Atomize */
    if((ret_value = H5I_register (H5I_DATASPACE, space, TRUE)) < 0)
        HGOTO_ERROR(H5E_ATOM, H5E_CANTREGISTER, FAIL, "unable to register dataspace atom")

done:
    FUNC_LEAVE_API(ret_value)
}   /* end H5Rget_region() */


/*--------------------------------------------------------------------------
 NAME
    H5R_get_obj_type
 PURPOSE
    Retrieves the type of object that an object reference points to
 USAGE
    H5O_type_t H5R_get_obj_type(file, ref_type, ref)
        H5F_t *file;        IN: File the object being dereferenced is within
        H5R_type_t ref_type;    IN: Type of reference to query
        void *ref;          IN: Reference to query.

 RETURNS
    Success:	An object type defined in H5Gpublic.h
    Failure:	H5G_UNKNOWN
 DESCRIPTION
    Given a reference to some object, this function returns the type of object
    pointed to.
 GLOBAL VARIABLES
 COMMENTS, BUGS, ASSUMPTIONS
 EXAMPLES
 REVISION LOG
--------------------------------------------------------------------------*/
herr_t
H5R_get_obj_type(H5F_t *file, hid_t dxpl_id, H5R_type_t ref_type,
    const void *_ref, H5O_type_t *obj_type)
{
    H5O_loc_t oloc;             /* Object location */
    unsigned rc;		/* Reference count of object    */
    herr_t ret_value = SUCCEED; /* Return value */

    FUNC_ENTER_NOAPI_NOINIT

    HDassert(file);
    HDassert(_ref);

    /* Initialize the symbol table entry */
    H5O_loc_reset(&oloc);
    oloc.file = file;

    switch(ref_type) {
        case H5R_OBJECT:
            /* Get the object oid */
            oloc.addr = *(const hobj_ref_t *)_ref; /* Only object references currently supported */
            break;

        case H5R_DATASET_REGION:
        {
            H5HG_t hobjid;      /* Heap object ID */
            const uint8_t *p;   /* Pointer to reference to decode */
            uint8_t *buf;       /* Buffer to store serialized selection in */

            /* Get the heap ID for the dataset region */
            p = (const uint8_t *)_ref;
            H5F_addr_decode(oloc.file, &p, &(hobjid.addr));
            UINT32DECODE(p, hobjid.idx);

            /* Get the dataset region from the heap (allocate inside routine) */
            if((buf = (uint8_t *)H5HG_read(oloc.file, dxpl_id, &hobjid, NULL, NULL)) == NULL)
                HGOTO_ERROR(H5E_REFERENCE, H5E_READERROR, FAIL, "Unable to read dataset region information")

            /* Get the object oid for the dataset */
            p = buf;
            H5F_addr_decode(oloc.file, &p, &(oloc.addr));

            /* Free the buffer allocated in H5HG_read() */
            H5MM_xfree(buf);
        } /* end case */
        break;

        case H5R_BADTYPE:
        case H5R_MAXTYPE:
        default:
            HDassert("unknown reference type" && 0);
            HGOTO_ERROR(H5E_REFERENCE, H5E_UNSUPPORTED, FAIL, "internal error (unknown reference type)")
    } /* end switch */

    /* Get the # of links for object, and its type */
    /* (To check to make certain that this object hasn't been deleted since the reference was created) */
    if(H5O_get_rc_and_type(&oloc, dxpl_id, &rc, obj_type) < 0 || 0 == rc)
        HGOTO_ERROR(H5E_REFERENCE, H5E_LINKCOUNT, FAIL, "dereferencing deleted object")

done:
    FUNC_LEAVE_NOAPI(ret_value)
}   /* end H5R_get_obj_type() */


/*--------------------------------------------------------------------------
 NAME
    H5Rget_obj_type2
 PURPOSE
    Retrieves the type of object that an object reference points to
 USAGE
    herr_t H5Rget_obj_type2(id, ref_type, ref, obj_type)
        hid_t id;       IN: Dataset reference object is in or location ID of
                            object that the dataset is located within.
        H5R_type_t ref_type;    IN: Type of reference to query
        void *ref;          IN: Reference to query.
        H5O_type_t *obj_type;   OUT: Type of object reference points to

 RETURNS
    Non-negative on success/Negative on failure
 DESCRIPTION
    Given a reference to some object, this function retrieves the type of
    object pointed to.
 GLOBAL VARIABLES
 COMMENTS, BUGS, ASSUMPTIONS
 EXAMPLES
 REVISION LOG
--------------------------------------------------------------------------*/
herr_t
H5Rget_obj_type2(hid_t id, H5R_type_t ref_type, const void *ref,
    H5O_type_t *obj_type)
{
    H5G_loc_t loc;              /* Object location */
    herr_t ret_value = SUCCEED; /* Return value */

    FUNC_ENTER_API(FAIL)
    H5TRACE4("e", "iRt*x*Ot", id, ref_type, ref, obj_type);

    /* Check args */
    if(H5G_loc(id, &loc) < 0)
        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a location")
    if(ref_type <= H5R_BADTYPE || ref_type >= H5R_MAXTYPE)
        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid reference type")
    if(ref == NULL)
        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid reference pointer")

    /* Get the object information */
    if(H5R_get_obj_type(loc.oloc->file, H5AC_ind_dxpl_id, ref_type, ref, obj_type) < 0)
	HGOTO_ERROR(H5E_REFERENCE, H5E_CANTINIT, FAIL, "unable to determine object type")

done:
    FUNC_LEAVE_API(ret_value)
}   /* end H5Rget_obj_type2() */


/*--------------------------------------------------------------------------
 NAME
    H5R_get_name
 PURPOSE
    Internal routine to determine a name for the object referenced
 USAGE
    ssize_t H5R_get_name(f, dxpl_id, ref_type, ref, name, size)
        H5F_t *f;       IN: Pointer to the file that the reference is pointing
                            into
        hid_t lapl_id;  IN: LAPL to use for operation
        hid_t dxpl_id;  IN: DXPL to use for operation
        hid_t id;       IN: Location ID given for reference
        H5R_type_t ref_type;    IN: Type of reference
        void *ref;      IN: Reference to query.
        char *name;     OUT: Buffer to place name of object referenced
        size_t size;    IN: Size of name buffer

 RETURNS
    Non-negative length of the path on success, Negative on failure
 DESCRIPTION
    Given a reference to some object, determine a path to the object
    referenced in the file.
 GLOBAL VARIABLES
 COMMENTS, BUGS, ASSUMPTIONS
    This may not be the only path to that object.
 EXAMPLES
 REVISION LOG
--------------------------------------------------------------------------*/
static ssize_t
H5R_get_name(H5F_t *f, hid_t lapl_id, hid_t dxpl_id, hid_t id, H5R_type_t ref_type,
    const void *_ref, char *name, size_t size)
{
    hid_t file_id = (-1);       /* ID for file that the reference is in */
    H5O_loc_t oloc;             /* Object location describing object for reference */
    ssize_t ret_value;          /* Return value */

    FUNC_ENTER_NOAPI_NOINIT

    /* Check args */
    HDassert(f);
    HDassert(_ref);
    HDassert(name);

    /* Initialize the object location */
    H5O_loc_reset(&oloc);
    oloc.file = f;

    /* Get address for reference */
    switch(ref_type) {
        case H5R_OBJECT:
            oloc.addr = *(const hobj_ref_t *)_ref;
            break;

        case H5R_DATASET_REGION:
        {
            H5HG_t hobjid;  /* Heap object ID */
            uint8_t *buf;   /* Buffer to store serialized selection in */
            const uint8_t *p;           /* Pointer to OID to store */

            /* Get the heap ID for the dataset region */
            p = (const uint8_t *)_ref;
            H5F_addr_decode(oloc.file, &p, &(hobjid.addr));
            UINT32DECODE(p, hobjid.idx);

            /* Get the dataset region from the heap (allocate inside routine) */
            if((buf = (uint8_t *)H5HG_read(oloc.file, dxpl_id, &hobjid, NULL, NULL)) == NULL)
                HGOTO_ERROR(H5E_REFERENCE, H5E_READERROR, FAIL, "Unable to read dataset region information")

            /* Get the object oid for the dataset */
            p = buf;
            H5F_addr_decode(oloc.file, &p, &(oloc.addr));

            /* Free the buffer allocated in H5HG_read() */
            H5MM_xfree(buf);
        } /* end case */
        break;

        case H5R_BADTYPE:
        case H5R_MAXTYPE:
        default:
            HDassert("unknown reference type" && 0);
            HGOTO_ERROR(H5E_REFERENCE, H5E_UNSUPPORTED, FAIL, "internal error (unknown reference type)")
    } /* end switch */

    /* Retrieve file ID for name search */
    if((file_id = H5I_get_file_id(id, FALSE)) < 0)
        HGOTO_ERROR(H5E_REFERENCE, H5E_CANTGET, FAIL, "can't retrieve file ID")

    /* Get name, length, etc. */
    if((ret_value = H5G_get_name_by_addr(file_id, lapl_id, dxpl_id, &oloc, name, size)) < 0)
        HGOTO_ERROR(H5E_REFERENCE, H5E_CANTGET, FAIL, "can't determine name")

done:
    /* Close file ID used for search */
    if(file_id > 0 && H5I_dec_ref(file_id) < 0)
        HDONE_ERROR(H5E_REFERENCE, H5E_CANTDEC, FAIL, "can't decrement ref count of temp ID")

    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5R_get_name() */


/*--------------------------------------------------------------------------
 NAME
    H5Rget_name
 PURPOSE
    Determines a name for the object referenced
 USAGE
    ssize_t H5Rget_name(loc_id, ref_type, ref, name, size)
        hid_t loc_id;   IN: Dataset reference object is in or location ID of
                            object that the dataset is located within.
        H5R_type_t ref_type;    IN: Type of reference
        void *ref;      IN: Reference to query.
        char *name;     OUT: Buffer to place name of object referenced
        size_t size;    IN: Size of name buffer

 RETURNS
    Non-negative length of the path on success, Negative on failure
 DESCRIPTION
    Given a reference to some object, determine a path to the object
    referenced in the file.
 GLOBAL VARIABLES
 COMMENTS, BUGS, ASSUMPTIONS
    This may not be the only path to that object.
 EXAMPLES
 REVISION LOG
--------------------------------------------------------------------------*/
ssize_t
H5Rget_name(hid_t id, H5R_type_t ref_type, const void *_ref, char *name,
    size_t size)
{
    H5G_loc_t loc;      /* Group location */
    H5F_t *file;        /* File object */
    ssize_t ret_value;  /* Return value */

    FUNC_ENTER_API(FAIL)
    H5TRACE5("Zs", "iRt*x*sz", id, ref_type, _ref, name, size);

    /* Check args */
    if(H5G_loc(id, &loc) < 0)
        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a location")
    if(ref_type <= H5R_BADTYPE || ref_type >= H5R_MAXTYPE)
        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid reference type")
    if(_ref == NULL)
        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid reference pointer")

    /* Get the file pointer from the entry */
    file = loc.oloc->file;

    /* Get name */
    if((ret_value = H5R_get_name(file, H5P_DEFAULT, H5AC_ind_dxpl_id, id, ref_type, _ref, name, size)) < 0)
        HGOTO_ERROR(H5E_REFERENCE, H5E_CANTINIT, FAIL, "unable to determine object path")

done:
    FUNC_LEAVE_API(ret_value)
} /* end H5Rget_name() */