summaryrefslogtreecommitdiffstats
path: root/src/H5Olayout.c
blob: e854884699740f943831ccdb7c69c3ba8bf378ae (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
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
 * 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 COPYING file, which can be found at the root of the source code       *
 * distribution tree, or in https://support.hdfgroup.org/ftp/HDF5/releases.  *
 * If you do not have access to either file, you may request a copy from     *
 * help@hdfgroup.org.                                                        *
 * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */

/* Programmer:  Robb Matzke <matzke@llnl.gov>
 *              Wednesday, October  8, 1997
 *
 * Purpose:     Messages related to data layout.
 */

#define H5D_FRIEND              /*suppress error about including H5Dpkg	  */
#include "H5Omodule.h"          /* This source code file is part of the H5O module */


#include "H5private.h"          /* Generic Functions                        */
#include "H5Dpkg.h"             /* Dataset functions                        */
#include "H5Eprivate.h"         /* Error handling                           */
#include "H5FLprivate.h"        /* Free Lists                               */
#include "H5MFprivate.h"        /* File space management                    */
#include "H5MMprivate.h"        /* Memory management                        */
#include "H5Opkg.h"             /* Object headers                           */
#include "H5Pprivate.h"         /* Property lists                           */


/* Local macros */


/* PRIVATE PROTOTYPES */
static void *H5O__layout_decode(H5F_t *f, H5O_t *open_oh, unsigned mesg_flags,
    unsigned *ioflags, const uint8_t *p);
static herr_t H5O__layout_encode(H5F_t *f, hbool_t disable_shared, uint8_t *p, const void *_mesg);
static void *H5O__layout_copy(const void *_mesg, void *_dest);
static size_t H5O__layout_size(const H5F_t *f, hbool_t disable_shared, const void *_mesg);
static herr_t H5O__layout_reset(void *_mesg);
static herr_t H5O__layout_free(void *_mesg);
static herr_t H5O__layout_delete(H5F_t *f, H5O_t *open_oh, void *_mesg);
static void *H5O__layout_copy_file(H5F_t *file_src, void *mesg_src,
    H5F_t *file_dst, hbool_t *recompute_size, unsigned *mesg_flags,
    H5O_copy_t *cpy_info, void *udata);
static herr_t H5O__layout_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_LAYOUT[1] = {{
    H5O_LAYOUT_ID,              /* message id number                    */
    "layout",                   /* message name for debugging           */
    sizeof(H5O_layout_t),       /* native message size                  */
    0,                          /* messages are sharable?               */
    H5O__layout_decode,         /* decode message                       */
    H5O__layout_encode,         /* encode message                       */
    H5O__layout_copy,           /* copy the native value                */
    H5O__layout_size,           /* size of message on disk              */
    H5O__layout_reset,          /* reset method                         */
    H5O__layout_free,           /* free the struct                      */
    H5O__layout_delete,	        /* file delete method                   */
    NULL,                       /* link method                          */
    NULL,                       /* set share method                     */
    NULL,                       /* can share method                     */
    NULL,                       /* pre copy native value to file        */
    H5O__layout_copy_file,      /* copy native value to file            */
    NULL,                       /* post copy native value to file       */
    NULL,                       /* get creation index                   */
    NULL,                       /* set creation index                   */
    H5O__layout_debug           /* debug the message                    */
}};


/* Declare a free list to manage the H5O_layout_t struct */
H5FL_DEFINE(H5O_layout_t);


/*-------------------------------------------------------------------------
 * Function:    H5O__layout_decode
 *
 * Purpose:     Decode an data layout message and return a pointer to a
 *              new one created with malloc().
 *
 * Return:      Success:        Ptr to new message in native order.
 *
 *              Failure:        NULL
 *
 * Programmer:  Robb Matzke
 *              Wednesday, October  8, 1997
 *
 *-------------------------------------------------------------------------
 */
static void *
H5O__layout_decode(H5F_t *f, H5O_t H5_ATTR_UNUSED *open_oh,
    unsigned H5_ATTR_UNUSED mesg_flags, unsigned H5_ATTR_UNUSED *ioflags, const uint8_t *p)
{
    H5O_layout_t           *mesg = NULL;
    uint8_t                *heap_block = NULL;
    unsigned               u;
    void                   *ret_value = NULL;   /* Return value */

    FUNC_ENTER_STATIC

    /* check args */
    HDassert(f);
    HDassert(p);

    /* decode */
    if(NULL == (mesg = H5FL_CALLOC(H5O_layout_t)))
        HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL, "memory allocation failed")
    mesg->storage.type = H5D_LAYOUT_ERROR;

    mesg->version = *p++;
    if(mesg->version < H5O_LAYOUT_VERSION_1 || mesg->version > H5O_LAYOUT_VERSION_4)
        HGOTO_ERROR(H5E_OHDR, H5E_CANTLOAD, NULL, "bad version number for layout message")

    if(mesg->version < H5O_LAYOUT_VERSION_3) {
        unsigned        ndims;          /* Num dimensions in chunk */

        /* Dimensionality */
        ndims = *p++;
        if(ndims > H5O_LAYOUT_NDIMS)
            HGOTO_ERROR(H5E_OHDR, H5E_CANTLOAD, NULL, "dimensionality is too large")

        /* Layout class */
        mesg->type = (H5D_layout_t)*p++;
        HDassert(H5D_CONTIGUOUS == mesg->type || H5D_CHUNKED == mesg->type || H5D_COMPACT == mesg->type);

        /* Set the storage type */
        mesg->storage.type = mesg->type;

        /* Reserved bytes */
        p += 5;

        /* Address */
        if(mesg->type == H5D_CONTIGUOUS) {
            H5F_addr_decode(f, &p, &(mesg->storage.u.contig.addr));

            /* Set the layout operations */
            mesg->ops = H5D_LOPS_CONTIG;
        } /* end if */
        else if(mesg->type == H5D_CHUNKED) {
            H5F_addr_decode(f, &p, &(mesg->storage.u.chunk.idx_addr));

            /* Set the layout operations */
            mesg->ops = H5D_LOPS_CHUNK;

            /* Set the chunk operations */
            /* (Only "btree" indexing type currently supported in this version) */
            mesg->storage.u.chunk.idx_type = H5D_CHUNK_IDX_BTREE;
            mesg->storage.u.chunk.ops = H5D_COPS_BTREE;
        } /* end if */
        else {
            /* Sanity check */
            HDassert(mesg->type == H5D_COMPACT);

            /* Set the layout operations */
            mesg->ops = H5D_LOPS_COMPACT;
        } /* end else */

        /* Read the size */
        if(mesg->type != H5D_CHUNKED) {
            /* Don't compute size of contiguous storage here, due to possible
             * truncation of the dimension sizes when they were stored in this
             * version of the layout message.  Compute the contiguous storage
             * size in the dataset code, where we've got the dataspace
             * information available also.  - QAK 5/26/04
             */
            p += ndims * 4;     /* Skip over dimension sizes (32-bit quantities) */
        } /* end if */
        else {
            mesg->u.chunk.ndims=ndims;
            for(u = 0; u < ndims; u++)
                UINT32DECODE(p, mesg->u.chunk.dim[u]);

            /* Compute chunk size */
            for(u = 1, mesg->u.chunk.size = mesg->u.chunk.dim[0]; u < ndims; u++)
                mesg->u.chunk.size *= mesg->u.chunk.dim[u];
        } /* end if */

        if(mesg->type == H5D_COMPACT) {
            UINT32DECODE(p, mesg->storage.u.compact.size);
            if(mesg->storage.u.compact.size > 0) {
                if(NULL == (mesg->storage.u.compact.buf = H5MM_malloc(mesg->storage.u.compact.size)))
                    HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL, "memory allocation failed for compact data buffer")
                HDmemcpy(mesg->storage.u.compact.buf, p, mesg->storage.u.compact.size);
                p += mesg->storage.u.compact.size;
            } /* end if */
        } /* end if */
    } /* end if */
    else {
        /* Layout & storage class */
        mesg->type = mesg->storage.type = (H5D_layout_t)*p++;

        /* Interpret the rest of the message according to the layout class */
        switch(mesg->type) {
            case H5D_COMPACT:
                /* Compact data size */
                UINT16DECODE(p, mesg->storage.u.compact.size);

                if(mesg->storage.u.compact.size > 0) {
                    /* Allocate space for compact data */
                    if(NULL == (mesg->storage.u.compact.buf = H5MM_malloc(mesg->storage.u.compact.size)))
                        HGOTO_ERROR(H5E_OHDR, H5E_CANTALLOC, NULL, "memory allocation failed for compact data buffer")

                    /* Compact data */
                    HDmemcpy(mesg->storage.u.compact.buf, p, mesg->storage.u.compact.size);
                    p += mesg->storage.u.compact.size;
                } /* end if */

                /* Set the layout operations */
                mesg->ops = H5D_LOPS_COMPACT;
                break;

            case H5D_CONTIGUOUS:
                /* Contiguous storage address */
                H5F_addr_decode(f, &p, &(mesg->storage.u.contig.addr));

                /* Contiguous storage size */
                H5F_DECODE_LENGTH(f, p, mesg->storage.u.contig.size);

                /* Set the layout operations */
                mesg->ops = H5D_LOPS_CONTIG;
                break;

            case H5D_CHUNKED:
                if(mesg->version < H5O_LAYOUT_VERSION_4) {
                    /* Set the chunked layout flags */
                    mesg->u.chunk.flags = (uint8_t)0;

                    /* Dimensionality */
                    mesg->u.chunk.ndims = *p++;
                    if(mesg->u.chunk.ndims > H5O_LAYOUT_NDIMS)
                        HGOTO_ERROR(H5E_OHDR, H5E_CANTLOAD, NULL, "dimensionality is too large")

                    /* B-tree address */
                    H5F_addr_decode(f, &p, &(mesg->storage.u.chunk.idx_addr));

                    /* Chunk dimensions */
                    for(u = 0; u < mesg->u.chunk.ndims; u++)
                        UINT32DECODE(p, mesg->u.chunk.dim[u]);

                    /* Compute chunk size */
                    for(u = 1, mesg->u.chunk.size = mesg->u.chunk.dim[0]; u < mesg->u.chunk.ndims; u++)
                        mesg->u.chunk.size *= mesg->u.chunk.dim[u];

                    /* Set the chunk operations */
                    /* (Only "btree" indexing type supported with v3 of message format) */
                    mesg->storage.u.chunk.idx_type = H5D_CHUNK_IDX_BTREE;
                    mesg->storage.u.chunk.ops = H5D_COPS_BTREE;
                } /* end if */
                else {
                    /* Get the chunked layout flags */
                    mesg->u.chunk.flags = *p++;

                    /* Check for valid flags */
                    /* (Currently issues an error for all non-zero values,
                     *      until features are added for the flags)
                     */
                    if(mesg->u.chunk.flags & ~H5O_LAYOUT_ALL_CHUNK_FLAGS)
                        HGOTO_ERROR(H5E_OHDR, H5E_BADVALUE, NULL, "bad flag value for message")

                    /* Dimensionality */
                    mesg->u.chunk.ndims = *p++;
                    if(mesg->u.chunk.ndims > H5O_LAYOUT_NDIMS)
                        HGOTO_ERROR(H5E_OHDR, H5E_BADVALUE, NULL, "dimensionality is too large")

                    /* Encoded # of bytes for each chunk dimension */
                    mesg->u.chunk.enc_bytes_per_dim = *p++;
                    if(mesg->u.chunk.enc_bytes_per_dim == 0 || mesg->u.chunk.enc_bytes_per_dim > 8)
                        HGOTO_ERROR(H5E_OHDR, H5E_BADVALUE, NULL, "encoded chunk dimension size is too large")

                    /* Chunk dimensions */
                    for(u = 0; u < mesg->u.chunk.ndims; u++)
                        UINT64DECODE_VAR(p, mesg->u.chunk.dim[u], mesg->u.chunk.enc_bytes_per_dim);

                    /* Compute chunk size */
                    for(u = 1, mesg->u.chunk.size = mesg->u.chunk.dim[0]; u < mesg->u.chunk.ndims; u++)
                        mesg->u.chunk.size *= mesg->u.chunk.dim[u];

                    /* Chunk index type */
                    mesg->u.chunk.idx_type = (H5D_chunk_index_t)*p++;
                    if(mesg->u.chunk.idx_type >= H5D_CHUNK_IDX_NTYPES)
                        HGOTO_ERROR(H5E_OHDR, H5E_BADVALUE, NULL, "unknown chunk index type")
                    mesg->storage.u.chunk.idx_type = mesg->u.chunk.idx_type;

                    switch(mesg->u.chunk.idx_type) {
                        case H5D_CHUNK_IDX_BTREE:
                            HGOTO_ERROR(H5E_OHDR, H5E_BADVALUE, NULL, "v1 B-tree index type should never be in a v4 layout message")
                            break;

                        case H5D_CHUNK_IDX_NONE:       /* Implicit Index */
                            mesg->storage.u.chunk.ops = H5D_COPS_NONE;
                            break;

                        case H5D_CHUNK_IDX_SINGLE:     /* Single Chunk Index */
                            if(mesg->u.chunk.flags & H5O_LAYOUT_CHUNK_SINGLE_INDEX_WITH_FILTER) {
                                H5F_DECODE_LENGTH(f, p, mesg->storage.u.chunk.u.single.nbytes);
                                UINT32DECODE(p, mesg->storage.u.chunk.u.single.filter_mask);
                            } /* end if */

                            /* Set the chunk operations */
                            mesg->storage.u.chunk.ops = H5D_COPS_SINGLE;
                            break;

                        case H5D_CHUNK_IDX_FARRAY:
                            /* Fixed array creation parameters */
                            mesg->u.chunk.u.farray.cparam.max_dblk_page_nelmts_bits = *p++;
                            if(0 == mesg->u.chunk.u.farray.cparam.max_dblk_page_nelmts_bits)
                                HGOTO_ERROR(H5E_OHDR, H5E_CANTLOAD, NULL, "invalid fixed array creation parameter")

                            /* Set the chunk operations */
                            mesg->storage.u.chunk.ops = H5D_COPS_FARRAY;
                            break;

                        case H5D_CHUNK_IDX_EARRAY:
                            /* Extensible array creation parameters */
                            mesg->u.chunk.u.earray.cparam.max_nelmts_bits = *p++;
                            if(0 == mesg->u.chunk.u.earray.cparam.max_nelmts_bits)
                                HGOTO_ERROR(H5E_OHDR, H5E_CANTLOAD, NULL, "invalid extensible array creation parameter")
                            mesg->u.chunk.u.earray.cparam.idx_blk_elmts = *p++;
                            if(0 == mesg->u.chunk.u.earray.cparam.idx_blk_elmts)
                                HGOTO_ERROR(H5E_OHDR, H5E_CANTLOAD, NULL, "invalid extensible array creation parameter")
                            mesg->u.chunk.u.earray.cparam.sup_blk_min_data_ptrs = *p++;
                            if(0 == mesg->u.chunk.u.earray.cparam.sup_blk_min_data_ptrs)
                                HGOTO_ERROR(H5E_OHDR, H5E_CANTLOAD, NULL, "invalid extensible array creation parameter")
                            mesg->u.chunk.u.earray.cparam.data_blk_min_elmts = *p++;
                            if(0 == mesg->u.chunk.u.earray.cparam.data_blk_min_elmts)
                                HGOTO_ERROR(H5E_OHDR, H5E_CANTLOAD, NULL, "invalid extensible array creation parameter")
                            mesg->u.chunk.u.earray.cparam.max_dblk_page_nelmts_bits = *p++;
                            if(0 == mesg->u.chunk.u.earray.cparam.max_dblk_page_nelmts_bits)
                                HGOTO_ERROR(H5E_OHDR, H5E_CANTLOAD, NULL, "invalid extensible array creation parameter")

                            /* Set the chunk operations */
                            mesg->storage.u.chunk.ops = H5D_COPS_EARRAY;
                            break;

                        case H5D_CHUNK_IDX_BT2:       /* v2 B-tree index */
                            UINT32DECODE(p, mesg->u.chunk.u.btree2.cparam.node_size);
                            mesg->u.chunk.u.btree2.cparam.split_percent = *p++;
                            mesg->u.chunk.u.btree2.cparam.merge_percent = *p++;

                            /* Set the chunk operations */
                            mesg->storage.u.chunk.ops = H5D_COPS_BT2;
                            break;

                        case H5D_CHUNK_IDX_NTYPES:
                        default:
                            HGOTO_ERROR(H5E_OHDR, H5E_BADVALUE, NULL, "Invalid chunk index type")
                    } /* end switch */

                    /* Chunk index address */
                    H5F_addr_decode(f, &p, &(mesg->storage.u.chunk.idx_addr));
                } /* end else */

                /* Set the layout operations */
                mesg->ops = H5D_LOPS_CHUNK;
                break;

            case H5D_VIRTUAL:
                /* Check version */
                if(mesg->version < H5O_LAYOUT_VERSION_4)
                    HGOTO_ERROR(H5E_OHDR, H5E_VERSION, NULL, "invalid layout version with virtual layout")
                
                /* Heap information */
                H5F_addr_decode(f, &p, &(mesg->storage.u.virt.serial_list_hobjid.addr));
                UINT32DECODE(p, mesg->storage.u.virt.serial_list_hobjid.idx);

                /* Initialize other fields */
                mesg->storage.u.virt.list_nused = 0;
                mesg->storage.u.virt.list = NULL;
                mesg->storage.u.virt.list_nalloc = 0;
                mesg->storage.u.virt.view = H5D_VDS_ERROR;
                mesg->storage.u.virt.printf_gap = HSIZE_UNDEF;
                mesg->storage.u.virt.source_fapl = -1;
                mesg->storage.u.virt.source_dapl = -1;
                mesg->storage.u.virt.init = FALSE;

                /* Decode heap block if it exists */
                if(mesg->storage.u.virt.serial_list_hobjid.addr != HADDR_UNDEF) {
                    const uint8_t *heap_block_p;
                    uint8_t heap_vers;
                    size_t block_size = 0;
                    size_t tmp_size;
                    hsize_t tmp_hsize;
                    uint32_t stored_chksum;
                    uint32_t computed_chksum;
                    size_t i;

                    /* Read heap */
                    if(NULL == (heap_block = (uint8_t *)H5HG_read(f, &(mesg->storage.u.virt.serial_list_hobjid), NULL, &block_size)))
                        HGOTO_ERROR(H5E_OHDR, H5E_READERROR, NULL, "Unable to read global heap block")

                    heap_block_p = (const uint8_t *)heap_block;

                    /* Decode the version number of the heap block encoding */
                    heap_vers = (uint8_t)*heap_block_p++;
                    if((uint8_t)H5O_LAYOUT_VDS_GH_ENC_VERS != heap_vers)
                        HGOTO_ERROR(H5E_OHDR, H5E_VERSION, NULL, "bad version # of encoded VDS heap information, expected %u, got %u", (unsigned)H5O_LAYOUT_VDS_GH_ENC_VERS, (unsigned)heap_vers)

                    /* Number of entries */
                    H5F_DECODE_LENGTH(f, heap_block_p, tmp_hsize)

                    /* Allocate entry list */
                    if(NULL == (mesg->storage.u.virt.list = (H5O_storage_virtual_ent_t *)H5MM_calloc((size_t)tmp_hsize * sizeof(H5O_storage_virtual_ent_t))))
                        HGOTO_ERROR(H5E_OHDR, H5E_RESOURCE, NULL, "unable to allocate heap block")
                    mesg->storage.u.virt.list_nalloc = (size_t)tmp_hsize;
                    mesg->storage.u.virt.list_nused = (size_t)tmp_hsize;

                    /* Decode each entry */
                    for(i = 0; i < mesg->storage.u.virt.list_nused; i++) {
                        /* Source file name */
                        tmp_size = HDstrlen((const char *)heap_block_p) + 1;
                        if(NULL == (mesg->storage.u.virt.list[i].source_file_name = (char *)H5MM_malloc(tmp_size)))
                            HGOTO_ERROR(H5E_OHDR, H5E_RESOURCE, NULL, "unable to allocate memory for source file name")
                        (void)HDmemcpy(mesg->storage.u.virt.list[i].source_file_name, heap_block_p, tmp_size);
                        heap_block_p += tmp_size;

                        /* Source dataset name */
                        tmp_size = HDstrlen((const char *)heap_block_p) + 1;
                        if(NULL == (mesg->storage.u.virt.list[i].source_dset_name = (char *)H5MM_malloc(tmp_size)))
                            HGOTO_ERROR(H5E_OHDR, H5E_RESOURCE, NULL, "unable to allocate memory for source dataset name")
                        (void)HDmemcpy(mesg->storage.u.virt.list[i].source_dset_name, heap_block_p, tmp_size);
                        heap_block_p += tmp_size;

                        /* Source selection */
                        if(H5S_SELECT_DESERIALIZE(&mesg->storage.u.virt.list[i].source_select, &heap_block_p) < 0)
                            HGOTO_ERROR(H5E_OHDR, H5E_CANTDECODE, NULL, "can't decode source space selection")

                        /* Virtual selection */
                        if(H5S_SELECT_DESERIALIZE(&mesg->storage.u.virt.list[i].source_dset.virtual_select, &heap_block_p) < 0)
                            HGOTO_ERROR(H5E_OHDR, H5E_CANTDECODE, NULL, "can't decode virtual space selection")

                        /* Parse source file and dataset names for "printf"
                         * style format specifiers */
                        if(H5D_virtual_parse_source_name(mesg->storage.u.virt.list[i].source_file_name, &mesg->storage.u.virt.list[i].parsed_source_file_name, &mesg->storage.u.virt.list[i].psfn_static_strlen, &mesg->storage.u.virt.list[i].psfn_nsubs) < 0)
                            HGOTO_ERROR(H5E_OHDR, H5E_CANTINIT, NULL, "can't parse source file name")
                        if(H5D_virtual_parse_source_name(mesg->storage.u.virt.list[i].source_dset_name, &mesg->storage.u.virt.list[i].parsed_source_dset_name, &mesg->storage.u.virt.list[i].psdn_static_strlen, &mesg->storage.u.virt.list[i].psdn_nsubs) < 0)
                            HGOTO_ERROR(H5E_OHDR, H5E_CANTINIT, NULL, "can't parse source dataset name")

                        /* Set source names in source_dset struct */
                        if((mesg->storage.u.virt.list[i].psfn_nsubs == 0)
                                && (mesg->storage.u.virt.list[i].psdn_nsubs == 0)) {
                            if(mesg->storage.u.virt.list[i].parsed_source_file_name)
                                mesg->storage.u.virt.list[i].source_dset.file_name = mesg->storage.u.virt.list[i].parsed_source_file_name->name_segment;
                            else
                                mesg->storage.u.virt.list[i].source_dset.file_name = mesg->storage.u.virt.list[i].source_file_name;
                            if(mesg->storage.u.virt.list[i].parsed_source_dset_name)
                                mesg->storage.u.virt.list[i].source_dset.dset_name = mesg->storage.u.virt.list[i].parsed_source_dset_name->name_segment;
                            else
                                mesg->storage.u.virt.list[i].source_dset.dset_name = mesg->storage.u.virt.list[i].source_dset_name;
                        } /* end if */

                        /* unlim_dim fields */
                        mesg->storage.u.virt.list[i].unlim_dim_source = H5S_get_select_unlim_dim(mesg->storage.u.virt.list[i].source_select);
                        mesg->storage.u.virt.list[i].unlim_dim_virtual = H5S_get_select_unlim_dim(mesg->storage.u.virt.list[i].source_dset.virtual_select);
                        mesg->storage.u.virt.list[i].unlim_extent_source = HSIZE_UNDEF;
                        mesg->storage.u.virt.list[i].unlim_extent_virtual = HSIZE_UNDEF;
                        mesg->storage.u.virt.list[i].clip_size_source = HSIZE_UNDEF;
                        mesg->storage.u.virt.list[i].clip_size_virtual = HSIZE_UNDEF;

                        /* Clipped selections */
                        if(mesg->storage.u.virt.list[i].unlim_dim_virtual < 0) {
                            mesg->storage.u.virt.list[i].source_dset.clipped_source_select = mesg->storage.u.virt.list[i].source_select;
                            mesg->storage.u.virt.list[i].source_dset.clipped_virtual_select = mesg->storage.u.virt.list[i].source_dset.virtual_select;
                        } /* end if */

                        /* Check mapping for validity (do both pre and post
                         * checks here, since we had to allocate the entry list
                         * before decoding the selections anyways) */
                        if(H5D_virtual_check_mapping_pre(mesg->storage.u.virt.list[i].source_dset.virtual_select, mesg->storage.u.virt.list[i].source_select, H5O_VIRTUAL_STATUS_INVALID) < 0)
                            HGOTO_ERROR(H5E_OHDR, H5E_BADVALUE, NULL, "invalid mapping selections")
                         if(H5D_virtual_check_mapping_post(&mesg->storage.u.virt.list[i]) < 0)
                            HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, NULL, "invalid mapping entry")

                        /* Update min_dims */
                        if(H5D_virtual_update_min_dims(mesg, i) < 0)
                            HGOTO_ERROR(H5E_OHDR, H5E_CANTINIT, NULL, "unable to update virtual dataset minimum dimensions")
                    } /* end for */

                    /* Read stored checksum */
                    UINT32DECODE(heap_block_p, stored_chksum)

                    /* Compute checksum */
                    computed_chksum = H5_checksum_metadata(heap_block, block_size - (size_t)4, 0);

                    /* Verify checksum */
                    if(stored_chksum != computed_chksum)
                        HGOTO_ERROR(H5E_OHDR, H5E_BADVALUE, NULL, "incorrect metadata checksum for global heap block")

                    /* Verify that the heap block size is correct */
                    if((size_t)(heap_block_p - heap_block) != block_size)
                        HGOTO_ERROR(H5E_OHDR, H5E_BADVALUE, NULL, "incorrect heap block size")
                } /* end if */

                /* Set the layout operations */
                mesg->ops = H5D_LOPS_VIRTUAL;

                break;

            case H5D_LAYOUT_ERROR:
            case H5D_NLAYOUTS:
            default:
                HGOTO_ERROR(H5E_OHDR, H5E_CANTLOAD, NULL, "Invalid layout class")
        } /* end switch */
    } /* end else */

    /* Set return value */
    ret_value = mesg;

done:
    if(ret_value == NULL)
        if(mesg) {
            if(mesg->type == H5D_VIRTUAL)
                if(H5D__virtual_reset_layout(mesg) < 0)
                    HDONE_ERROR(H5E_OHDR, H5E_CANTFREE, NULL, "unable to reset virtual layout")
            mesg = H5FL_FREE(H5O_layout_t, mesg);
        } /* end if */

    heap_block = (uint8_t *)H5MM_xfree(heap_block);

    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5O__layout_decode() */


/*-------------------------------------------------------------------------
 * Function:    H5O__layout_encode
 *
 * Purpose:     Encodes a message.
 *
 * Return:      Non-negative on success/Negative on failure
 *
 * Programmer:  Robb Matzke
 *              Wednesday, October  8, 1997
 *
 * Note:
 *      Quincey Koziol, 2004-5-21
 *      We write out version 3 messages by default now.
 *
 *-------------------------------------------------------------------------
 */
static herr_t
H5O__layout_encode(H5F_t *f, hbool_t H5_ATTR_UNUSED disable_shared, uint8_t *p, const void *_mesg)
{
    const H5O_layout_t     *mesg = (const H5O_layout_t *) _mesg;
    unsigned               u;
    herr_t ret_value = SUCCEED;   /* Return value */

    FUNC_ENTER_STATIC

    /* check args */
    HDassert(f);
    HDassert(mesg);
    HDassert(p);

    /* Message version */
    *p++ = (uint8_t)((mesg->version < H5O_LAYOUT_VERSION_3) ?
             H5O_LAYOUT_VERSION_3 : mesg->version);

    /* Layout class */
    *p++ = mesg->type;

    /* Write out layout class specific information */
    switch(mesg->type) {
        case H5D_COMPACT:
            /* Size of raw data */
            UINT16ENCODE(p, mesg->storage.u.compact.size);

            /* Raw data */
            if(mesg->storage.u.compact.size > 0) {
                if(mesg->storage.u.compact.buf)
                    HDmemcpy(p, mesg->storage.u.compact.buf, mesg->storage.u.compact.size);
                else
                    HDmemset(p, 0, mesg->storage.u.compact.size);
                p += mesg->storage.u.compact.size;
            } /* end if */
            break;

        case H5D_CONTIGUOUS:
            /* Contiguous storage address */
            H5F_addr_encode(f, &p, mesg->storage.u.contig.addr);

            /* Contiguous storage size */
            H5F_ENCODE_LENGTH(f, p, mesg->storage.u.contig.size);
            break;

        case H5D_CHUNKED:
            if(mesg->version < H5O_LAYOUT_VERSION_4) {
                /* Number of dimensions */
                HDassert(mesg->u.chunk.ndims > 0 && mesg->u.chunk.ndims <= H5O_LAYOUT_NDIMS);
                *p++ = (uint8_t)mesg->u.chunk.ndims;

                /* B-tree address */
                H5F_addr_encode(f, &p, mesg->storage.u.chunk.idx_addr);

                /* Dimension sizes */
                for(u = 0; u < mesg->u.chunk.ndims; u++)
                    UINT32ENCODE(p, mesg->u.chunk.dim[u]);
            } /* end if */
            else {
                /* Chunk feature flags */
                *p++ = mesg->u.chunk.flags;

                /* Number of dimensions */
                HDassert(mesg->u.chunk.ndims > 0 && mesg->u.chunk.ndims <= H5O_LAYOUT_NDIMS);
                *p++ = (uint8_t)mesg->u.chunk.ndims;

                /* Encoded # of bytes for each chunk dimension */
                HDassert(mesg->u.chunk.enc_bytes_per_dim > 0 && mesg->u.chunk.enc_bytes_per_dim <= 8);
                *p++ = (uint8_t)mesg->u.chunk.enc_bytes_per_dim;

                /* Dimension sizes */
                for(u = 0; u < mesg->u.chunk.ndims; u++)
                    UINT64ENCODE_VAR(p, mesg->u.chunk.dim[u], mesg->u.chunk.enc_bytes_per_dim);

                /* Chunk index type */
                *p++ = (uint8_t)mesg->u.chunk.idx_type;

                switch(mesg->u.chunk.idx_type) {
                    case H5D_CHUNK_IDX_BTREE:
                        HGOTO_ERROR(H5E_OHDR, H5E_BADVALUE, FAIL, "v1 B-tree index type should never be in a v4 layout message")
                        break;

                    case H5D_CHUNK_IDX_NONE:       /* Implicit */
                        break;

                    case H5D_CHUNK_IDX_SINGLE:     /* Single Chunk */
                        /* Filter information */
                        if(mesg->u.chunk.flags & H5O_LAYOUT_CHUNK_SINGLE_INDEX_WITH_FILTER) {
                            H5F_ENCODE_LENGTH(f, p, mesg->storage.u.chunk.u.single.nbytes);
                            UINT32ENCODE(p, mesg->storage.u.chunk.u.single.filter_mask);
                        } /* end if */
                        break;

                    case H5D_CHUNK_IDX_FARRAY:
                        /* Fixed array creation parameters */
                        *p++ = mesg->u.chunk.u.farray.cparam.max_dblk_page_nelmts_bits;
                        break;

                    case H5D_CHUNK_IDX_EARRAY:
                        /* Extensible array creation parameters */
                        *p++ = mesg->u.chunk.u.earray.cparam.max_nelmts_bits;
                        *p++ = mesg->u.chunk.u.earray.cparam.idx_blk_elmts;
                        *p++ = mesg->u.chunk.u.earray.cparam.sup_blk_min_data_ptrs;
                        *p++ = mesg->u.chunk.u.earray.cparam.data_blk_min_elmts;
                        *p++ = mesg->u.chunk.u.earray.cparam.max_dblk_page_nelmts_bits;
                        break;

                    case H5D_CHUNK_IDX_BT2:       /* v2 B-tree index */
                        UINT32ENCODE(p, mesg->u.chunk.u.btree2.cparam.node_size);
                        *p++ = mesg->u.chunk.u.btree2.cparam.split_percent;
                        *p++ = mesg->u.chunk.u.btree2.cparam.merge_percent;
                        break;

                    case H5D_CHUNK_IDX_NTYPES:
                    default:
                        HGOTO_ERROR(H5E_OHDR, H5E_CANTENCODE, FAIL, "Invalid chunk index type")
                } /* end switch */

                /*
                 * Implicit index: Address of the chunks
                 * Single chunk index: address of the single chunk
                 * Other indexes: chunk index address
                 */
                H5F_addr_encode(f, &p, mesg->storage.u.chunk.idx_addr);
            } /* end else */
            break;

        case H5D_VIRTUAL:
            /* Encode heap ID for VDS info */
            H5F_addr_encode(f, &p, mesg->storage.u.virt.serial_list_hobjid.addr);
            UINT32ENCODE(p, mesg->storage.u.virt.serial_list_hobjid.idx);
            break;

        case H5D_LAYOUT_ERROR:
        case H5D_NLAYOUTS:
        default:
            HGOTO_ERROR(H5E_OHDR, H5E_CANTENCODE, FAIL, "Invalid layout class")
    } /* end switch */

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5O__layout_encode() */


/*-------------------------------------------------------------------------
 * Function:    H5O__layout_copy
 *
 * Purpose:     Copies a message from _MESG to _DEST, allocating _DEST if
 *              necessary.
 *
 * Return:      Success:        Ptr to _DEST
 *
 *              Failure:        NULL
 *
 * Programmer:  Robb Matzke
 *              Wednesday, October  8, 1997
 *
 *-------------------------------------------------------------------------
 */
static void *
H5O__layout_copy(const void *_mesg, void *_dest)
{
    const H5O_layout_t     *mesg = (const H5O_layout_t *) _mesg;
    H5O_layout_t           *dest = (H5O_layout_t *) _dest;
    void                   *ret_value = NULL;   /* Return value */

    FUNC_ENTER_STATIC

    /* check args */
    HDassert(mesg);

    /* Allocate destination message, if necessary */
    if(!dest && NULL == (dest = H5FL_MALLOC(H5O_layout_t)))
        HGOTO_ERROR(H5E_OHDR, H5E_CANTALLOC, NULL, "layout message allocation failed")

    /* copy */
    *dest = *mesg;

    /* Special actions for each type of layout */
    switch(mesg->type) {
        case H5D_COMPACT:
            /* Deep copy the buffer for compact datasets also */
            if(mesg->storage.u.compact.size > 0) {
                /* Sanity check */
                HDassert(mesg->storage.u.compact.buf);

                /* Allocate memory for the raw data */
                if(NULL == (dest->storage.u.compact.buf = H5MM_malloc(dest->storage.u.compact.size)))
                    HGOTO_ERROR(H5E_OHDR, H5E_NOSPACE, NULL, "unable to allocate memory for compact dataset")

                /* Copy over the raw data */
                HDmemcpy(dest->storage.u.compact.buf, mesg->storage.u.compact.buf, dest->storage.u.compact.size);
            } /* end if */
            else
                HDassert(dest->storage.u.compact.buf == NULL);
            break;

        case H5D_CONTIGUOUS:
            /* Nothing required */
            break;

        case H5D_CHUNKED:
            /* Reset the pointer of the chunked storage index but not the address */
            if(dest->storage.u.chunk.ops)
                H5D_chunk_idx_reset(&dest->storage.u.chunk, FALSE);
            break;

        case H5D_VIRTUAL:
            if(H5D__virtual_copy_layout(dest) < 0)
                HGOTO_ERROR(H5E_OHDR, H5E_CANTCOPY, NULL, "unable to copy virtual layout")
            break;

        case H5D_LAYOUT_ERROR:
        case H5D_NLAYOUTS:
        default:
            HGOTO_ERROR(H5E_OHDR, H5E_CANTENCODE, NULL, "Invalid layout class")
    } /* end switch */

    /* Set return value */
    ret_value = dest;

done:
    if(ret_value == NULL)
        if(NULL == _dest)
            dest = H5FL_FREE(H5O_layout_t, dest);

    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5O__layout_copy() */


/*-------------------------------------------------------------------------
 * Function:    H5O__layout_size
 *
 * Purpose:     Returns the size of the raw message in bytes.  If it's
 *              compact dataset, the data part is also included.
 *              This function doesn't take into account message alignment.
 *
 * Return:      Success:        Message data size in bytes
 *
 *              Failure:        0
 *
 * Programmer:  Robb Matzke
 *              Wednesday, October  8, 1997
 *
 *-------------------------------------------------------------------------
 */
static size_t
H5O__layout_size(const H5F_t *f, hbool_t H5_ATTR_UNUSED disable_shared, const void *_mesg)
{
    const H5O_layout_t     *mesg = (const H5O_layout_t *) _mesg;
    size_t                  ret_value = 0;      /* Return value */

    FUNC_ENTER_STATIC_NOERR

    /* check args */
    HDassert(f);
    HDassert(mesg);

    /* Compute serialized size */
    /* (including possibly compact data) */
    ret_value = H5D__layout_meta_size(f, mesg, TRUE);

    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5O__layout_size() */


/*-------------------------------------------------------------------------
 * Function:    H5O__layout_reset
 *
 * Purpose:     Frees resources within a data type message, but doesn't free
 *              the message itself.
 *
 * Return:      Non-negative on success/Negative on failure
 *
 * Programmer:  Quincey Koziol
 *              Friday, September 13, 2002
 *
 *-------------------------------------------------------------------------
 */
static herr_t
H5O__layout_reset(void *_mesg)
{
    H5O_layout_t     *mesg = (H5O_layout_t *)_mesg;
    herr_t ret_value = SUCCEED;         /* Return value */

    FUNC_ENTER_STATIC

    if(mesg) {
        /* Free the compact storage buffer */
        if(H5D_COMPACT == mesg->type)
            mesg->storage.u.compact.buf = H5MM_xfree(mesg->storage.u.compact.buf);
        else if(H5D_VIRTUAL == mesg->type)
            /* Free the virtual entry list */
            if(H5D__virtual_reset_layout(mesg) < 0)
                HGOTO_ERROR(H5E_OHDR, H5E_CANTFREE, FAIL, "unable to reset virtual layout")

        /* Reset the message */
        mesg->type = H5D_CONTIGUOUS;
        mesg->version = H5O_LAYOUT_VERSION_DEFAULT;
    } /* end if */

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5O__layout_reset() */


/*-------------------------------------------------------------------------
 * Function:	H5O__layout_free
 *
 * Purpose:	Free's the message
 *
 * Return:	Non-negative on success/Negative on failure
 *
 * Programmer:	Quincey Koziol
 *              Saturday, March 11, 2000
 *
 *-------------------------------------------------------------------------
 */
static herr_t
H5O__layout_free(void *_mesg)
{
    H5O_layout_t     *mesg = (H5O_layout_t *) _mesg;

    FUNC_ENTER_STATIC_NOERR

    HDassert(mesg);

    /* Free resources within the message */
    H5O__layout_reset(mesg);

    (void)H5FL_FREE(H5O_layout_t, mesg);

    FUNC_LEAVE_NOAPI(SUCCEED)
} /* end H5O__layout_free() */


/*-------------------------------------------------------------------------
 * Function:    H5O__layout_delete
 *
 * Purpose:     Free file space referenced by message
 *
 * Return:      Non-negative on success/Negative on failure
 *
 * Programmer:  Quincey Koziol
 *              Wednesday, March 19, 2003
 *
 *-------------------------------------------------------------------------
 */
static herr_t
H5O__layout_delete(H5F_t *f, H5O_t *open_oh, void *_mesg)
{
    H5O_layout_t *mesg = (H5O_layout_t *) _mesg;
    herr_t ret_value = SUCCEED;   /* Return value */

    FUNC_ENTER_STATIC

    /* check args */
    HDassert(f);
    HDassert(open_oh);
    HDassert(mesg);

    /* Perform different actions, depending on the type of storage */
    switch(mesg->type) {
        case H5D_COMPACT:       /* Compact data storage */
            /* Nothing required */
            break;

        case H5D_CONTIGUOUS:    /* Contiguous block on disk */
            /* Free the file space for the raw data */
            if(H5D__contig_delete(f, &mesg->storage) < 0)
                HGOTO_ERROR(H5E_OHDR, H5E_CANTFREE, FAIL, "unable to free raw data")
            break;

        case H5D_CHUNKED:       /* Chunked blocks on disk */
            /* Free the file space for the index & chunk raw data */
            if(H5D__chunk_delete(f, open_oh, &mesg->storage) < 0)
                HGOTO_ERROR(H5E_OHDR, H5E_CANTFREE, FAIL, "unable to free raw data")
            break;

        case H5D_VIRTUAL:       /* Virtual dataset */
            /* Free the file space virtual dataset */
            if(H5D__virtual_delete(f, &mesg->storage) < 0)
                HGOTO_ERROR(H5E_OHDR, H5E_CANTFREE, FAIL, "unable to free raw data")
            break;

        case H5D_LAYOUT_ERROR:
        case H5D_NLAYOUTS:
        default:
            HGOTO_ERROR(H5E_OHDR, H5E_BADTYPE, FAIL, "not valid storage type")
    } /* end switch */

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5O__layout_delete() */


/*-------------------------------------------------------------------------
 * Function:    H5O__layout_copy_file
 *
 * Purpose:     Copies a message from _MESG to _DEST in file
 *
 * Return:      Success:        Ptr to _DEST
 *
 *              Failure:        NULL
 *
 * Programmer:  Peter Cao
 *              July 23, 2005
 *
 *-------------------------------------------------------------------------
 */
static void *
H5O__layout_copy_file(H5F_t *file_src, void *mesg_src, H5F_t *file_dst,
    hbool_t H5_ATTR_UNUSED *recompute_size, unsigned H5_ATTR_UNUSED *mesg_flags,
    H5O_copy_t *cpy_info, void *_udata)
{
    H5D_copy_file_ud_t *udata = (H5D_copy_file_ud_t *)_udata;   /* Dataset copying user data */
    H5O_layout_t       *layout_src = (H5O_layout_t *) mesg_src;
    H5O_layout_t       *layout_dst = NULL;
    hbool_t             copied = FALSE;         /* Whether the data was copied */
    void               *ret_value = NULL;       /* Return value */

    FUNC_ENTER_STATIC

    /* check args */
    HDassert(file_src);
    HDassert(layout_src);
    HDassert(file_dst);

    /* Copy the layout information */
    if(NULL == (layout_dst = (H5O_layout_t *)H5O__layout_copy(layout_src, NULL)))
        HGOTO_ERROR(H5E_OHDR, H5E_CANTCOPY, NULL, "unable to copy layout")

    /* Copy the layout type specific information */
    switch(layout_src->type) {
        case H5D_COMPACT:
            if(layout_src->storage.u.compact.buf) {
                /* copy compact raw data */
                if(H5D__compact_copy(file_src, &layout_src->storage.u.compact, file_dst, &layout_dst->storage.u.compact, udata->src_dtype, cpy_info) < 0)
                    HGOTO_ERROR(H5E_OHDR, H5E_CANTCOPY, NULL, "unable to copy chunked storage")
                copied = TRUE;
            } /* end if */
            break;

        case H5D_CONTIGUOUS:
            /* Compute the size of the contiguous storage for versions of the
             * layout message less than version 3 because versions 1 & 2 would
             * truncate the dimension sizes to 32-bits of information. - QAK 5/26/04
             */
            if(layout_src->version < H5O_LAYOUT_VERSION_3)
                layout_dst->storage.u.contig.size = H5S_extent_nelem(udata->src_space_extent) *
                                        H5T_get_size(udata->src_dtype);

            if(H5D__contig_is_space_alloc(&layout_src->storage)) {
                /* copy contiguous raw data */
                if(H5D__contig_copy(file_src, &layout_src->storage.u.contig, file_dst, &layout_dst->storage.u.contig, udata->src_dtype, cpy_info) < 0)
                    HGOTO_ERROR(H5E_OHDR, H5E_CANTCOPY, NULL, "unable to copy contiguous storage")
                copied = TRUE;
            } /* end if */
            break;

        case H5D_CHUNKED:
            if(H5D__chunk_is_space_alloc(&layout_src->storage)) {
                /* Create chunked layout */
                if(H5D__chunk_copy(file_src, &layout_src->storage.u.chunk, &layout_src->u.chunk, file_dst, &layout_dst->storage.u.chunk, udata->src_space_extent, udata->src_dtype, udata->common.src_pline, cpy_info) < 0)
                    HGOTO_ERROR(H5E_OHDR, H5E_CANTCOPY, NULL, "unable to copy chunked storage")
                copied = TRUE;
            } /* end if */
            break;

        case H5D_VIRTUAL:
            /* Copy virtual layout.  Always copy so the memory fields get copied
             * properly. */
            if(H5D__virtual_copy(file_dst, layout_dst) < 0)
                HGOTO_ERROR(H5E_OHDR, H5E_CANTCOPY, NULL, "unable to copy virtual storage")
            break;

        case H5D_LAYOUT_ERROR:
        case H5D_NLAYOUTS:
        default:
            HGOTO_ERROR(H5E_OHDR, H5E_CANTLOAD, NULL, "Invalid layout class")
    } /* end switch */

    /* Check if copy routine was invoked (which frees the source datatype) */
    if(copied)
        udata->src_dtype = NULL;

    /* Set return value */
    ret_value = layout_dst;

done:
    if(!ret_value)
	if(layout_dst)
	    layout_dst = H5FL_FREE(H5O_layout_t, layout_dst);

    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5O__layout_copy_file() */


/*-------------------------------------------------------------------------
 * Function:    H5O__layout_debug
 *
 * Purpose:     Prints debugging info for a message.
 *
 * Return:      Non-negative on success/Negative on failure
 *
 * Programmer:  Robb Matzke
 *              Wednesday, October  8, 1997
 *
 *-------------------------------------------------------------------------
 */
static herr_t
H5O__layout_debug(H5F_t H5_ATTR_UNUSED *f, const void *_mesg, FILE *stream,
    int indent, int fwidth)
{
    const H5O_layout_t     *mesg = (const H5O_layout_t *) _mesg;
    size_t                  u;

    FUNC_ENTER_STATIC_NOERR

    /* check args */
    HDassert(f);
    HDassert(mesg);
    HDassert(stream);
    HDassert(indent >= 0);
    HDassert(fwidth >= 0);

    HDfprintf(stream, "%*s%-*s %u\n", indent, "", fwidth,
              "Version:", mesg->version);
    switch(mesg->type) {
        case H5D_CHUNKED:
            HDfprintf(stream, "%*s%-*s %s\n", indent, "", fwidth,
                      "Type:", "Chunked");

            /* Chunk # of dims & size */
            HDfprintf(stream, "%*s%-*s %lu\n", indent, "", fwidth,
                      "Number of dimensions:",
                      (unsigned long)(mesg->u.chunk.ndims));
            HDfprintf(stream, "%*s%-*s {", indent, "", fwidth, "Size:");
            for(u = 0; u < (size_t)mesg->u.chunk.ndims; u++)
                HDfprintf(stream, "%s%lu", u ? ", " : "", (unsigned long)(mesg->u.chunk.dim[u]));
            HDfprintf(stream, "}\n");

            /* Index information */
            switch(mesg->u.chunk.idx_type) {
                case H5D_CHUNK_IDX_BTREE:
                    HDfprintf(stream, "%*s%-*s %s\n", indent, "", fwidth,
                              "Index Type:", "v1 B-tree");
                    break;

                case H5D_CHUNK_IDX_NONE:
                    HDfprintf(stream, "%*s%-*s %s\n", indent, "", fwidth,
                              "Index Type:", "Implicit");
                    break;

                case H5D_CHUNK_IDX_SINGLE:
                    HDfprintf(stream, "%*s%-*s %s\n", indent, "", fwidth,
                              "Index Type:", "Single Chunk");
                    break;

                case H5D_CHUNK_IDX_FARRAY:
                    HDfprintf(stream, "%*s%-*s %s\n", indent, "", fwidth,
                              "Index Type:", "Fixed Array");
                    /* (Should print the fixed array creation parameters) */
                    break;

                case H5D_CHUNK_IDX_EARRAY:
                    HDfprintf(stream, "%*s%-*s %s\n", indent, "", fwidth,
                              "Index Type:", "Extensible Array");
                    /* (Should print the extensible array creation parameters) */
                    break;

                case H5D_CHUNK_IDX_BT2:
                    HDfprintf(stream, "%*s%-*s %s\n", indent, "", fwidth,
                              "Index Type:", "v2 B-tree");
                    /* (Should print the v2-Btree creation parameters) */
                    break;

                case H5D_CHUNK_IDX_NTYPES:
                default:
                    HDfprintf(stream, "%*s%-*s %s (%u)\n", indent, "", fwidth,
                              "Index Type:", "Unknown", (unsigned)mesg->u.chunk.idx_type);
                    break;
            } /* end switch */
            HDfprintf(stream, "%*s%-*s %a\n", indent, "", fwidth,
                      "Index address:", mesg->storage.u.chunk.idx_addr);
            break;

        case H5D_CONTIGUOUS:
            HDfprintf(stream, "%*s%-*s %s\n", indent, "", fwidth,
                      "Type:", "Contiguous");
            HDfprintf(stream, "%*s%-*s %a\n", indent, "", fwidth,
                      "Data address:", mesg->storage.u.contig.addr);
            HDfprintf(stream, "%*s%-*s %Hu\n", indent, "", fwidth,
                      "Data Size:", mesg->storage.u.contig.size);
            break;

        case H5D_COMPACT:
            HDfprintf(stream, "%*s%-*s %s\n", indent, "", fwidth,
                      "Type:", "Compact");
            HDfprintf(stream, "%*s%-*s %Zu\n", indent, "", fwidth,
                      "Data Size:", mesg->storage.u.compact.size);
            break;

        case H5D_VIRTUAL:
            HDfprintf(stream, "%*s%-*s %s\n", indent, "", fwidth,
                      "Type:", "Virtual");
            HDfprintf(stream, "%*s%-*s %a\n", indent, "", fwidth,
                      "Global heap address:", mesg->storage.u.virt.serial_list_hobjid.addr);
            HDfprintf(stream, "%*s%-*s %Zu\n", indent, "", fwidth,
                      "Global heap index:", mesg->storage.u.virt.serial_list_hobjid.idx);
            for(u = 0; u < mesg->storage.u.virt.list_nused; u++) {
                HDfprintf(stream, "%*sMapping %u:\n", indent, "", u);
                HDfprintf(stream, "%*s%-*s %s\n", indent + 3, "", fwidth - 3,
                      "Virtual selection:", "<Not yet implemented>");
                HDfprintf(stream, "%*s%-*s %s\n", indent + 3, "", fwidth - 3,
                      "Source file name:", mesg->storage.u.virt.list[u].source_file_name);
                HDfprintf(stream, "%*s%-*s %s\n", indent + 3, "", fwidth - 3,
                      "Source dataset name:", mesg->storage.u.virt.list[u].source_dset_name);
                HDfprintf(stream, "%*s%-*s %s\n", indent + 3, "", fwidth - 3,
                      "Source selection:", "<Not yet implemented>");
            } /* end for */
            break;

        case H5D_LAYOUT_ERROR:
        case H5D_NLAYOUTS:
        default:
            HDfprintf(stream, "%*s%-*s %s (%u)\n", indent, "", fwidth,
                      "Type:", "Unknown", (unsigned)mesg->type);
            break;
    } /* end switch */

    FUNC_LEAVE_NOAPI(SUCCEED)
} /* end H5O__layout_debug() */