summaryrefslogtreecommitdiffstats
path: root/src/H5Olink.c
blob: 6657a500c169112beb465c609130789b1120123b (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
/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
 * Copyright by The HDF Group.                                               *
 * 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 COPYING file, which can be found at the root of the source code       *
 * distribution tree, or in https://www.hdfgroup.org/licenses.               *
 * If you do not have access to either file, you may request a copy from     *
 * help@hdfgroup.org.                                                        *
 * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */

/*-------------------------------------------------------------------------
 *
 * Created:             H5Olink.c
 *
 * Purpose:             Link messages
 *
 *-------------------------------------------------------------------------
 */

#define H5G_FRIEND     /*suppress error about including H5Gpkg   */
#define H5L_FRIEND     /*suppress error about including H5Lpkg	  */
#include "H5Omodule.h" /* This source code file is part of the H5O module */

#include "H5private.h"   /* Generic Functions			*/
#include "H5Eprivate.h"  /* Error handling		  	*/
#include "H5FLprivate.h" /* Free lists                           */
#include "H5Gpkg.h"      /* Groups		  		*/
#include "H5Iprivate.h"  /* IDs                                  */
#include "H5Lpkg.h"      /* Links                                */
#include "H5MMprivate.h" /* Memory management			*/
#include "H5Opkg.h"      /* Object headers			*/

/* PRIVATE PROTOTYPES */
static void *H5O__link_decode(H5F_t *f, H5O_t *open_oh, unsigned mesg_flags, unsigned *ioflags, size_t p_size,
                              const uint8_t *p);
static herr_t H5O__link_encode(H5F_t *f, bool disable_shared, size_t H5_ATTR_UNUSED p_size, uint8_t *p,
                               const void *_mesg);
static void  *H5O__link_copy(const void *_mesg, void *_dest);
static size_t H5O__link_size(const H5F_t *f, bool disable_shared, const void *_mesg);
static herr_t H5O__link_reset(void *_mesg);
static herr_t H5O__link_free(void *_mesg);
static herr_t H5O__link_pre_copy_file(H5F_t *file_src, const void *mesg_src, bool *deleted,
                                      const H5O_copy_t *cpy_info, void *udata);
static void  *H5O__link_copy_file(H5F_t *file_src, void *native_src, H5F_t *file_dst, bool *recompute_size,
                                  unsigned *mesg_flags, H5O_copy_t *cpy_info, void *udata);
static herr_t H5O__link_post_copy_file(const H5O_loc_t *src_oloc, const void *mesg_src, H5O_loc_t *dst_oloc,
                                       void *mesg_dst, unsigned *mesg_flags, H5O_copy_t *cpy_info);
static herr_t H5O__link_debug(H5F_t *f, const void *_mesg, FILE *stream, int indent, int fwidth);

/* This message derives from H5O message class */
const H5O_msg_class_t H5O_MSG_LINK[1] = {{
    H5O_LINK_ID,              /*message id number             */
    "link",                   /*message name for debugging    */
    sizeof(H5O_link_t),       /*native message size           */
    0,                        /* messages are shareable?       */
    H5O__link_decode,         /*decode message                */
    H5O__link_encode,         /*encode message                */
    H5O__link_copy,           /*copy the native value         */
    H5O__link_size,           /*size of symbol table entry    */
    H5O__link_reset,          /* reset method			*/
    H5O__link_free,           /* free method			*/
    H5O_link_delete,          /* file delete method		*/
    NULL,                     /* link method			*/
    NULL,                     /*set share method		*/
    NULL,                     /*can share method		*/
    H5O__link_pre_copy_file,  /* pre copy native value to file */
    H5O__link_copy_file,      /* copy native value to file    */
    H5O__link_post_copy_file, /* post copy native value to file    */
    NULL,                     /* get creation index		*/
    NULL,                     /* set creation index		*/
    H5O__link_debug           /*debug the message             */
}};

/* Current version of link information */
#define H5O_LINK_VERSION 1

/* Flags for link flag encoding */
#define H5O_LINK_NAME_SIZE       0x03 /* 2-bit field for size of name length */
#define H5O_LINK_STORE_CORDER    0x04 /* Whether to store creation index */
#define H5O_LINK_STORE_LINK_TYPE 0x08 /* Whether to store non-default link type */
#define H5O_LINK_STORE_NAME_CSET 0x10 /* Whether to store non-default name character set */
#define H5O_LINK_ALL_FLAGS                                                                                   \
    (H5O_LINK_NAME_SIZE | H5O_LINK_STORE_CORDER | H5O_LINK_STORE_LINK_TYPE | H5O_LINK_STORE_NAME_CSET)

/* Individual definitions of name size values */
#define H5O_LINK_NAME_1 0x00 /* Use 1-byte value for name length */
#define H5O_LINK_NAME_2 0x01 /* Use 2-byte value for name length */
#define H5O_LINK_NAME_4 0x02 /* Use 4-byte value for name length */
#define H5O_LINK_NAME_8 0x03 /* Use 8-byte value for name length */

/* Declare a free list to manage the H5O_link_t struct */
H5FL_DEFINE_STATIC(H5O_link_t);

/*-------------------------------------------------------------------------
 * Function:    H5O__link_decode
 *
 * Purpose:     Decode a message and return a pointer to
 *              a newly allocated one.
 *
 * Return:      Success:    Pointer to new message in native order
 *              Failure:    NULL
 *-------------------------------------------------------------------------
 */
static void *
H5O__link_decode(H5F_t *f, H5O_t H5_ATTR_UNUSED *open_oh, unsigned H5_ATTR_UNUSED mesg_flags,
                 unsigned H5_ATTR_UNUSED *ioflags, size_t p_size, const uint8_t *p)
{
    H5O_link_t    *lnk = NULL;                 /* Pointer to link message */
    size_t         len = 0;                    /* Length of a string in the message */
    unsigned char  link_flags;                 /* Flags for encoding link info */
    const uint8_t *p_end     = p + p_size - 1; /* End of the p buffer */
    void          *ret_value = NULL;

    FUNC_ENTER_PACKAGE

    assert(f);
    assert(p);

    if (H5_IS_BUFFER_OVERFLOW(p, 1, p_end))
        HGOTO_ERROR(H5E_OHDR, H5E_OVERFLOW, NULL, "ran off end of input buffer while decoding");
    if (*p++ != H5O_LINK_VERSION)
        HGOTO_ERROR(H5E_OHDR, H5E_CANTLOAD, NULL, "bad version number for message");

    /* Allocate space for message */
    if (NULL == (lnk = H5FL_CALLOC(H5O_link_t)))
        HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL, "memory allocation failed");

    /* Get the encoding flags for the link */
    if (H5_IS_BUFFER_OVERFLOW(p, 1, p_end))
        HGOTO_ERROR(H5E_OHDR, H5E_OVERFLOW, NULL, "ran off end of input buffer while decoding");
    link_flags = *p++;
    if (link_flags & ~H5O_LINK_ALL_FLAGS)
        HGOTO_ERROR(H5E_OHDR, H5E_CANTLOAD, NULL, "bad flag value for message");

    /* Check for non-default link type */
    if (link_flags & H5O_LINK_STORE_LINK_TYPE) {
        /* Get the type of the link */
        if (H5_IS_BUFFER_OVERFLOW(p, 1, p_end))
            HGOTO_ERROR(H5E_OHDR, H5E_OVERFLOW, NULL, "ran off end of input buffer while decoding");
        lnk->type = (H5L_type_t)*p++;
        if (lnk->type < H5L_TYPE_HARD || lnk->type > H5L_TYPE_MAX)
            HGOTO_ERROR(H5E_OHDR, H5E_CANTLOAD, NULL, "bad link type");
    }
    else
        lnk->type = H5L_TYPE_HARD;

    /* Get the link creation time from the file */
    if (link_flags & H5O_LINK_STORE_CORDER) {
        if (H5_IS_BUFFER_OVERFLOW(p, 8, p_end))
            HGOTO_ERROR(H5E_OHDR, H5E_OVERFLOW, NULL, "ran off end of input buffer while decoding");
        INT64DECODE(p, lnk->corder);
        lnk->corder_valid = true;
    }
    else {
        lnk->corder       = 0;
        lnk->corder_valid = false;
    }

    /* Check for non-default name character set */
    if (link_flags & H5O_LINK_STORE_NAME_CSET) {
        /* Get the link name's character set */
        if (H5_IS_BUFFER_OVERFLOW(p, 1, p_end))
            HGOTO_ERROR(H5E_OHDR, H5E_OVERFLOW, NULL, "ran off end of input buffer while decoding");
        lnk->cset = (H5T_cset_t)*p++;
        if (lnk->cset < H5T_CSET_ASCII || lnk->cset > H5T_CSET_UTF8)
            HGOTO_ERROR(H5E_OHDR, H5E_CANTLOAD, NULL, "bad cset type");
    }
    else
        lnk->cset = H5T_CSET_ASCII;

    /* Get the length of the link's name */
    switch (link_flags & H5O_LINK_NAME_SIZE) {
        case 0: /* 1 byte size */
            if (H5_IS_BUFFER_OVERFLOW(p, 1, p_end))
                HGOTO_ERROR(H5E_OHDR, H5E_OVERFLOW, NULL, "ran off end of input buffer while decoding");
            len = *p++;
            break;

        case 1: /* 2 byte size */
            if (H5_IS_BUFFER_OVERFLOW(p, 2, p_end))
                HGOTO_ERROR(H5E_OHDR, H5E_OVERFLOW, NULL, "ran off end of input buffer while decoding");
            UINT16DECODE(p, len);
            break;

        case 2: /* 4 byte size */
            if (H5_IS_BUFFER_OVERFLOW(p, 4, p_end))
                HGOTO_ERROR(H5E_OHDR, H5E_OVERFLOW, NULL, "ran off end of input buffer while decoding");
            UINT32DECODE(p, len);
            break;

        case 3: /* 8 byte size */
            if (H5_IS_BUFFER_OVERFLOW(p, 8, p_end))
                HGOTO_ERROR(H5E_OHDR, H5E_OVERFLOW, NULL, "ran off end of input buffer while decoding");
            UINT64DECODE(p, len);
            break;

        default:
            HGOTO_ERROR(H5E_OHDR, H5E_BADVALUE, NULL, "no appropriate size for name length");
    }
    if (len == 0)
        HGOTO_ERROR(H5E_OHDR, H5E_CANTLOAD, NULL, "invalid name length");

    /* Get the link's name */
    if (H5_IS_BUFFER_OVERFLOW(p, len, p_end))
        HGOTO_ERROR(H5E_OHDR, H5E_OVERFLOW, NULL, "ran off end of input buffer while decoding");
    if (NULL == (lnk->name = (char *)H5MM_malloc(len + 1)))
        HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL, "memory allocation failed");
    H5MM_memcpy(lnk->name, p, len);
    lnk->name[len] = '\0';
    p += len;

    /* Get the appropriate information for each type of link */
    switch (lnk->type) {
        case H5L_TYPE_HARD:
            /* Get the address of the object the link points to */
            if (H5_IS_BUFFER_OVERFLOW(p, H5F_sizeof_addr(f), p_end))
                HGOTO_ERROR(H5E_OHDR, H5E_OVERFLOW, NULL, "ran off end of input buffer while decoding");
            H5F_addr_decode(f, &p, &(lnk->u.hard.addr));
            break;

        case H5L_TYPE_SOFT:
            /* Get the link value */
            if (H5_IS_BUFFER_OVERFLOW(p, 2, p_end))
                HGOTO_ERROR(H5E_OHDR, H5E_OVERFLOW, NULL, "ran off end of input buffer while decoding");
            UINT16DECODE(p, len);
            if (len == 0)
                HGOTO_ERROR(H5E_OHDR, H5E_CANTLOAD, NULL, "invalid link length");

            if (H5_IS_BUFFER_OVERFLOW(p, len, p_end))
                HGOTO_ERROR(H5E_OHDR, H5E_OVERFLOW, NULL, "ran off end of input buffer while decoding");
            if (NULL == (lnk->u.soft.name = (char *)H5MM_malloc((size_t)len + 1)))
                HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL, "memory allocation failed");
            H5MM_memcpy(lnk->u.soft.name, p, len);
            lnk->u.soft.name[len] = '\0';
            p += len;
            break;

        /* User-defined links */
        case H5L_TYPE_EXTERNAL:
        case H5L_TYPE_ERROR:
        case H5L_TYPE_MAX:
        default:
            if (lnk->type < H5L_TYPE_UD_MIN || lnk->type > H5L_TYPE_MAX)
                HGOTO_ERROR(H5E_OHDR, H5E_CANTLOAD, NULL, "unknown link type");

            /* A UD link.  Get the user-supplied data */
            if (H5_IS_BUFFER_OVERFLOW(p, 2, p_end))
                HGOTO_ERROR(H5E_OHDR, H5E_OVERFLOW, NULL, "ran off end of input buffer while decoding");
            UINT16DECODE(p, len);
            if (lnk->type == H5L_TYPE_EXTERNAL && len < 3)
                HGOTO_ERROR(H5E_OHDR, H5E_OVERFLOW, NULL, "external link information length < 3");
            lnk->u.ud.size = len;
            if (len > 0) {
                if (H5_IS_BUFFER_OVERFLOW(p, len, p_end))
                    HGOTO_ERROR(H5E_OHDR, H5E_OVERFLOW, NULL, "ran off end of input buffer while decoding");
                if (NULL == (lnk->u.ud.udata = H5MM_malloc((size_t)len)))
                    HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL, "memory allocation failed");
                H5MM_memcpy(lnk->u.ud.udata, p, len);
                p += len;
            }
            else
                lnk->u.ud.udata = NULL;
    }

    /* Set return value */
    ret_value = lnk;

done:
    if (!ret_value && lnk) {
        H5MM_xfree(lnk->name);
        if (lnk->type == H5L_TYPE_SOFT && lnk->u.soft.name != NULL)
            H5MM_xfree(lnk->u.soft.name);
        if (lnk->type >= H5L_TYPE_UD_MIN && lnk->u.ud.size > 0 && lnk->u.ud.udata != NULL)
            H5MM_xfree(lnk->u.ud.udata);
        H5FL_FREE(H5O_link_t, lnk);
    }

    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5O__link_decode() */

/*-------------------------------------------------------------------------
 * Function:    H5O__link_encode
 *
 * Purpose:     Encodes a link message.
 *
 * Return:      Non-negative on success/Negative on failure
 *
 *-------------------------------------------------------------------------
 */
static herr_t
H5O__link_encode(H5F_t *f, bool H5_ATTR_UNUSED disable_shared, size_t H5_ATTR_UNUSED p_size, uint8_t *p,
                 const void *_mesg)
{
    const H5O_link_t *lnk = (const H5O_link_t *)_mesg;
    uint64_t          len;        /* Length of a string in the message */
    unsigned char     link_flags; /* Flags for encoding link info */

    FUNC_ENTER_PACKAGE_NOERR

    /* check args */
    assert(f);
    assert(p);
    assert(lnk);

    /* Get length of link's name */
    len = (uint64_t)strlen(lnk->name);
    assert(len > 0);

    /* encode */
    *p++ = H5O_LINK_VERSION;

    /* The encoding flags for the link */
    if (len > 4294967295)
        link_flags = H5O_LINK_NAME_8;
    else if (len > 65535)
        link_flags = H5O_LINK_NAME_4;
    else if (len > 255)
        link_flags = H5O_LINK_NAME_2;
    else
        link_flags = H5O_LINK_NAME_1;
    link_flags = (unsigned char)(link_flags | (lnk->corder_valid ? H5O_LINK_STORE_CORDER : 0));
    link_flags = (unsigned char)(link_flags | ((lnk->type != H5L_TYPE_HARD) ? H5O_LINK_STORE_LINK_TYPE : 0));
    link_flags = (unsigned char)(link_flags | ((lnk->cset != H5T_CSET_ASCII) ? H5O_LINK_STORE_NAME_CSET : 0));
    *p++       = link_flags;

    /* Store the type of a non-default link */
    if (link_flags & H5O_LINK_STORE_LINK_TYPE)
        *p++ = (uint8_t)lnk->type;

    /* Store the link creation order in the file, if its valid */
    if (lnk->corder_valid)
        INT64ENCODE(p, lnk->corder);

    /* Store a non-default link name character set */
    if (link_flags & H5O_LINK_STORE_NAME_CSET)
        *p++ = (uint8_t)lnk->cset;

    /* Store the link name's length */
    switch (link_flags & H5O_LINK_NAME_SIZE) {
        case 0: /* 1 byte size */
            *p++ = (uint8_t)len;
            break;

        case 1: /* 2 byte size */
            UINT16ENCODE(p, len);
            break;

        case 2: /* 4 byte size */
            UINT32ENCODE(p, len);
            break;

        case 3: /* 8 byte size */
            UINT64ENCODE(p, len);
            break;

        default:
            assert(0 && "bad size for name");
    } /* end switch */

    /* Store the link's name */
    H5MM_memcpy(p, lnk->name, (size_t)len);
    p += len;

    /* Store the appropriate information for each type of link */
    switch (lnk->type) {
        case H5L_TYPE_HARD:
            /* Store the address of the object the link points to */
            H5F_addr_encode(f, &p, lnk->u.hard.addr);
            break;

        case H5L_TYPE_SOFT:
            /* Store the link value */
            len = (uint16_t)strlen(lnk->u.soft.name);
            assert(len > 0);
            UINT16ENCODE(p, len);
            H5MM_memcpy(p, lnk->u.soft.name, (size_t)len);
            p += len;
            break;

        /* User-defined links */
        case H5L_TYPE_EXTERNAL:
        case H5L_TYPE_ERROR:
        case H5L_TYPE_MAX:
        default:
            assert(lnk->type >= H5L_TYPE_UD_MIN && lnk->type <= H5L_TYPE_MAX);

            /* Store the user-supplied data, however long it is */
            len = (uint16_t)lnk->u.ud.size;
            UINT16ENCODE(p, len);
            if (len > 0) {
                H5MM_memcpy(p, lnk->u.ud.udata, (size_t)len);
                p += len;
            }
            break;
    } /* end switch */

    FUNC_LEAVE_NOAPI(SUCCEED)
} /* end H5O__link_encode() */

/*-------------------------------------------------------------------------
 * Function:    H5O__link_copy
 *
 * Purpose:     Copies a message from _MESG to _DEST, allocating _DEST if
 *              necessary.
 *
 * Return:      Success:        Ptr to _DEST
 *
 *              Failure:        NULL
 *
 *-------------------------------------------------------------------------
 */
static void *
H5O__link_copy(const void *_mesg, void *_dest)
{
    const H5O_link_t *lnk       = (const H5O_link_t *)_mesg;
    H5O_link_t       *dest      = (H5O_link_t *)_dest;
    void             *ret_value = NULL; /* Return value */

    FUNC_ENTER_PACKAGE

    /* Check args */
    assert(lnk);
    if (!dest && NULL == (dest = H5FL_MALLOC(H5O_link_t)))
        HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL, "memory allocation failed");

    /* Copy static information */
    *dest = *lnk;

    /* Duplicate the link's name */
    assert(lnk->name);
    if (NULL == (dest->name = H5MM_xstrdup(lnk->name)))
        HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL, "can't duplicate link name");

    /* Copy other information needed for different link types */
    if (lnk->type == H5L_TYPE_SOFT) {
        if (NULL == (dest->u.soft.name = H5MM_xstrdup(lnk->u.soft.name)))
            HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL, "can't duplicate soft link value");
    } /* end if */
    else if (lnk->type >= H5L_TYPE_UD_MIN) {
        if (lnk->u.ud.size > 0) {
            if (NULL == (dest->u.ud.udata = H5MM_malloc(lnk->u.ud.size)))
                HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL, "memory allocation failed");
            H5MM_memcpy(dest->u.ud.udata, lnk->u.ud.udata, lnk->u.ud.size);
        } /* end if */
    }     /* end if */

    /* Set return value */
    ret_value = dest;

done:
    if (NULL == ret_value)
        if (dest) {
            if (dest->name && dest->name != lnk->name)
                dest->name = (char *)H5MM_xfree(dest->name);
            if (NULL == _dest)
                dest = H5FL_FREE(H5O_link_t, dest);
        } /* end if */

    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5O__link_copy() */

/*-------------------------------------------------------------------------
 * Function:    H5O__link_size
 *
 * Purpose:     Returns the size of the raw message in bytes not counting
 *              the message type or size fields, but only the data fields.
 *              This function doesn't take into account alignment.
 *
 * Return:      Success:        Message data size in bytes without alignment.
 *
 *              Failure:        zero
 *
 *-------------------------------------------------------------------------
 */
static size_t
H5O__link_size(const H5F_t *f, bool H5_ATTR_UNUSED disable_shared, const void *_mesg)
{
    const H5O_link_t *lnk = (const H5O_link_t *)_mesg;
    uint64_t          name_len;      /* Length of name */
    size_t            name_size;     /* Size of encoded name length */
    size_t            ret_value = 0; /* Return value */

    FUNC_ENTER_PACKAGE_NOERR

    /* Sanity check */
    HDcompile_assert(sizeof(uint64_t) >= sizeof(size_t));

    /* Get name's length */
    name_len = (uint64_t)strlen(lnk->name);

    /* Determine correct value for name size bits */
    if (name_len > 4294967295)
        name_size = 8;
    else if (name_len > 65535)
        name_size = 4;
    else if (name_len > 255)
        name_size = 2;
    else
        name_size = 1;

    /* Set return value */
    ret_value = 1 +                                            /* Version */
                1 +                                            /* Link encoding flags */
                (lnk->type != H5L_TYPE_HARD ? (size_t)1 : 0) + /* Link type */
                (lnk->corder_valid ? 8 : 0) +                  /* Creation order */
                (lnk->cset != H5T_CSET_ASCII ? 1 : 0) +        /* Character set */
                name_size +                                    /* Name length */
                name_len;                                      /* Name */

    /* Add the appropriate length for each type of link */
    switch (lnk->type) {
        case H5L_TYPE_HARD:
            ret_value += H5F_SIZEOF_ADDR(f);
            break;

        case H5L_TYPE_SOFT:
            ret_value += 2 +                       /* Link value length */
                         strlen(lnk->u.soft.name); /* Link value */
            break;

        case H5L_TYPE_ERROR:
        case H5L_TYPE_EXTERNAL:
        case H5L_TYPE_MAX:
        default: /* Default is user-defined link type */
            assert(lnk->type >= H5L_TYPE_UD_MIN);
            ret_value += 2 +             /* User-defined data size */
                         lnk->u.ud.size; /* User-defined data */
            break;
    } /* end switch */

    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5O__link_size() */

/*-------------------------------------------------------------------------
 * Function:	H5O__link_reset
 *
 * Purpose:	Frees resources within a message, but doesn't free
 *		the message itself.
 *
 * Return:	Non-negative on success/Negative on failure
 *
 *-------------------------------------------------------------------------
 */
static herr_t
H5O__link_reset(void *_mesg)
{
    H5O_link_t *lnk = (H5O_link_t *)_mesg;

    FUNC_ENTER_PACKAGE_NOERR

    if (lnk) {
        /* Free information for link (but don't free link pointer) */
        if (lnk->type == H5L_TYPE_SOFT)
            lnk->u.soft.name = (char *)H5MM_xfree(lnk->u.soft.name);
        else if (lnk->type >= H5L_TYPE_UD_MIN) {
            if (lnk->u.ud.size > 0)
                lnk->u.ud.udata = H5MM_xfree(lnk->u.ud.udata);
        } /* end if */
        lnk->name = (char *)H5MM_xfree(lnk->name);
    } /* end if */

    FUNC_LEAVE_NOAPI(SUCCEED)
} /* end H5O__link_reset() */

/*-------------------------------------------------------------------------
 * Function:	H5O__link_free
 *
 * Purpose:	Frees the message contents and the message itself
 *
 * Return:	Non-negative on success/Negative on failure
 *
 *-------------------------------------------------------------------------
 */
static herr_t
H5O__link_free(void *_mesg)
{
    H5O_link_t *lnk = (H5O_link_t *)_mesg;

    FUNC_ENTER_PACKAGE_NOERR

    assert(lnk);

    lnk = H5FL_FREE(H5O_link_t, lnk);

    FUNC_LEAVE_NOAPI(SUCCEED)
} /* end H5O__link_free() */

/*-------------------------------------------------------------------------
 * Function:    H5O_link_delete
 *
 * Purpose:     Free file space referenced by message
 *
 * Return:      Non-negative on success/Negative on failure
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5O_link_delete(H5F_t *f, H5O_t H5_ATTR_UNUSED *open_oh, void *_mesg)
{
    H5O_link_t *lnk       = (H5O_link_t *)_mesg;
    hid_t       file_id   = -1;      /* ID for the file the link is located in (passed to user callback) */
    herr_t      ret_value = SUCCEED; /* Return value */

    FUNC_ENTER_NOAPI(FAIL)

    /* check args */
    assert(f);
    assert(lnk);

    /* Check for adjusting the link count when the link is removed */
    /* Adjust the reference count of the object when a hard link is removed */
    if (lnk->type == H5L_TYPE_HARD) {
        H5O_loc_t oloc;

        /* Construct object location for object, in order to decrement it's ref count */
        H5O_loc_reset(&oloc);
        oloc.file = f;
        assert(H5_addr_defined(lnk->u.hard.addr));
        oloc.addr = lnk->u.hard.addr;

        /* Decrement the ref count for the object */
        if (H5O_link(&oloc, -1) < 0)
            HGOTO_ERROR(H5E_OHDR, H5E_CANTFREE, FAIL, "unable to decrement object link count");
    } /* end if */
    /* Perform the "delete" callback when a user-defined link is removed */
    else if (lnk->type >= H5L_TYPE_UD_MIN) {
        const H5L_class_t *link_class; /* User-defined link class */

        /* Get the link class for this type of link. */
        if (NULL == (link_class = H5L_find_class(lnk->type)))
            HGOTO_ERROR(H5E_OHDR, H5E_NOTREGISTERED, FAIL, "link class not registered");

        /* Check for delete callback */
        if (link_class->del_func) {
            /* Get a file ID for the file the link is in */
            if ((file_id = H5F_get_id(f)) < 0)
                HGOTO_ERROR(H5E_OHDR, H5E_CANTGET, FAIL, "unable to get file ID");

            /* Call user-defined link's 'delete' callback */
            if ((link_class->del_func)(lnk->name, file_id, lnk->u.ud.udata, lnk->u.ud.size) < 0)
                HGOTO_ERROR(H5E_OHDR, H5E_CALLBACK, FAIL, "link deletion callback returned failure");
        } /* end if */
    }     /* end if */

done:
    /* Release the file ID */
    if (file_id > 0 && H5I_dec_ref(file_id) < 0)
        HDONE_ERROR(H5E_OHDR, H5E_CANTCLOSEFILE, FAIL, "can't close file");

    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5O_link_delete() */

/*-------------------------------------------------------------------------
 * Function:    H5O__link_pre_copy_file
 *
 * Purpose:     Perform any necessary actions before copying message between
 *              files for link messages.
 *
 * Return:      Success:        Non-negative
 *
 *              Failure:        Negative
 *
 *-------------------------------------------------------------------------
 */
static herr_t
H5O__link_pre_copy_file(H5F_t H5_ATTR_UNUSED *file_src, const void H5_ATTR_UNUSED *native_src, bool *deleted,
                        const H5O_copy_t *cpy_info, void H5_ATTR_UNUSED *udata)
{
    FUNC_ENTER_PACKAGE_NOERR

    /* check args */
    assert(deleted);
    assert(cpy_info);

    /* If we are performing a 'shallow hierarchy' copy, and this link won't
     *  be included in the final group, indicate that it should be deleted
     *  in the destination object header before performing any other actions
     *  on it.
     */
    if (cpy_info->max_depth >= 0 && cpy_info->curr_depth >= cpy_info->max_depth)
        *deleted = true;

    FUNC_LEAVE_NOAPI(SUCCEED)
} /* end H5O__link_pre_copy_file() */

/*-------------------------------------------------------------------------
 * Function:    H5O__link_copy_file
 *
 * Purpose:     Copies a message from _MESG to _DEST in file
 *
 * Return:      Success:        Ptr to _DEST
 *
 *              Failure:        NULL
 *
 *-------------------------------------------------------------------------
 */
static void *
H5O__link_copy_file(H5F_t H5_ATTR_UNUSED *file_src, void *native_src, H5F_t H5_ATTR_UNUSED *file_dst,
                    bool H5_ATTR_UNUSED *recompute_size, unsigned H5_ATTR_UNUSED *mesg_flags,
                    H5O_copy_t H5_ATTR_UNUSED *cpy_info, void H5_ATTR_UNUSED *udata)
{
    H5O_link_t *link_src  = (H5O_link_t *)native_src;
    void       *ret_value = NULL; /* Return value */

    FUNC_ENTER_PACKAGE

    /* check args */
    assert(link_src);
    assert(cpy_info);
    assert(cpy_info->max_depth < 0 || cpy_info->curr_depth < cpy_info->max_depth);

    /* Sanity check source link type */
    if (link_src->type > H5L_TYPE_SOFT && link_src->type < H5L_TYPE_UD_MIN)
        HGOTO_ERROR(H5E_SYM, H5E_BADVALUE, NULL, "unrecognized built-in link type");

    /* Allocate "blank" link for destination */
    /* (values will be filled in during 'post copy' operation) */
    if (NULL == (ret_value = H5FL_CALLOC(H5O_link_t)))
        HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL, "memory allocation failed");

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* H5O__link_copy_file() */

/*-------------------------------------------------------------------------
 * Function:    H5O__link_post_copy_file
 *
 * Purpose:     Finish copying a message from between files
 *
 * Return:      Non-negative on success/Negative on failure
 *
 *-------------------------------------------------------------------------
 */
static herr_t
H5O__link_post_copy_file(const H5O_loc_t *src_oloc, const void *mesg_src, H5O_loc_t *dst_oloc, void *mesg_dst,
                         unsigned H5_ATTR_UNUSED *mesg_flags, H5O_copy_t *cpy_info)
{
    const H5O_link_t *link_src  = (const H5O_link_t *)mesg_src;
    H5O_link_t       *link_dst  = (H5O_link_t *)mesg_dst;
    herr_t            ret_value = SUCCEED; /* Return value */

    FUNC_ENTER_PACKAGE

    /* check args */
    assert(link_src);
    assert(dst_oloc);
    assert(H5_addr_defined(dst_oloc->addr));
    assert(dst_oloc->file);
    assert(link_dst);
    assert(cpy_info);
    assert(cpy_info->max_depth < 0 || cpy_info->curr_depth < cpy_info->max_depth);

    /* Copy the link (and the object it points to) */
    if (H5L__link_copy_file(dst_oloc->file, link_src, src_oloc, link_dst, cpy_info) < 0)
        HGOTO_ERROR(H5E_OHDR, H5E_CANTCOPY, FAIL, "unable to copy link");

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* H5O__link_post_copy_file() */

/*-------------------------------------------------------------------------
 * Function:    H5O__link_debug
 *
 * Purpose:     Prints debugging info for a message.
 *
 * Return:      Non-negative on success/Negative on failure
 *
 *-------------------------------------------------------------------------
 */
static herr_t
H5O__link_debug(H5F_t H5_ATTR_UNUSED *f, const void *_mesg, FILE *stream, int indent, int fwidth)
{
    const H5O_link_t *lnk       = (const H5O_link_t *)_mesg;
    herr_t            ret_value = SUCCEED; /* Return value */

    FUNC_ENTER_PACKAGE

    /* check args */
    assert(f);
    assert(lnk);
    assert(stream);
    assert(indent >= 0);
    assert(fwidth >= 0);

    fprintf(stream, "%*s%-*s %s\n", indent, "", fwidth, "Link Type:",
            (lnk->type == H5L_TYPE_HARD
                 ? "Hard"
                 : (lnk->type == H5L_TYPE_SOFT
                        ? "Soft"
                        : (lnk->type == H5L_TYPE_EXTERNAL
                               ? "External"
                               : (lnk->type >= H5L_TYPE_UD_MIN ? "User-defined" : "Unknown")))));

    if (lnk->corder_valid)
        fprintf(stream, "%*s%-*s %" PRId64 "\n", indent, "", fwidth, "Creation Order:", lnk->corder);

    fprintf(stream, "%*s%-*s %s\n", indent, "", fwidth, "Link Name Character Set:",
            (lnk->cset == H5T_CSET_ASCII ? "ASCII" : (lnk->cset == H5T_CSET_UTF8 ? "UTF-8" : "Unknown")));
    fprintf(stream, "%*s%-*s '%s'\n", indent, "", fwidth, "Link Name:", lnk->name);

    /* Display link-specific information */
    switch (lnk->type) {
        case H5L_TYPE_HARD:
            fprintf(stream, "%*s%-*s %" PRIuHADDR "\n", indent, "", fwidth,
                    "Object address:", lnk->u.hard.addr);
            break;

        case H5L_TYPE_SOFT:
            fprintf(stream, "%*s%-*s '%s'\n", indent, "", fwidth, "Link Value:", lnk->u.soft.name);
            break;

        case H5L_TYPE_ERROR:
        case H5L_TYPE_EXTERNAL:
        case H5L_TYPE_MAX:
        default:
            if (lnk->type >= H5L_TYPE_UD_MIN) {
                if (lnk->type == H5L_TYPE_EXTERNAL) {
                    const char *objname =
                        (const char *)lnk->u.ud.udata + (strlen((const char *)lnk->u.ud.udata) + 1);

                    fprintf(stream, "%*s%-*s %s\n", indent, "", fwidth,
                            "External File Name:", (const char *)lnk->u.ud.udata);
                    fprintf(stream, "%*s%-*s %s\n", indent, "", fwidth, "External Object Name:", objname);
                } /* end if */
                else {
                    fprintf(stream, "%*s%-*s %zu\n", indent, "", fwidth,
                            "User-Defined Link Size:", lnk->u.ud.size);
                } /* end else */
            }     /* end if */
            else
                HGOTO_ERROR(H5E_SYM, H5E_BADVALUE, FAIL, "unrecognized link type");
            break;
    } /* end switch */

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5O__link_debug() */