summaryrefslogtreecommitdiffstats
path: root/tools/lib/h5diff_dset.c
blob: b03295bae3c1f75901565c1168db914423cb741b (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
/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
 * 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.                                                        *
 * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */

#include "H5private.h"
#include "h5tools.h"
#include "h5tools_utils.h"
#include "h5diff.h"
#include "ph5diff.h"


/*-------------------------------------------------------------------------
 * Function: diff_dataset
 *
 * Purpose: check for comparable datasets and read into a compatible
 *  memory type
 *
 * Return: Number of differences found
 *-------------------------------------------------------------------------
 */
hsize_t diff_dataset(hid_t file1_id,
                     hid_t file2_id,
                     const char *obj1_name,
                     const char *obj2_name,
                     diff_opt_t *opts)
{
    int     ret_value = opts->err_stat;
    int     status = -1;
    hid_t   did1 = -1;
    hid_t   did2 = -1;
    hid_t   dcpl1 = -1;
    hid_t   dcpl2 = -1;
    hsize_t nfound = 0;

    h5difftrace("diff_dataset start\n");
    /*-------------------------------------------------------------------------
     * open the handles
     *-------------------------------------------------------------------------
     */
    /* Open the datasets */
    if((did1 = H5Dopen2(file1_id, obj1_name, H5P_DEFAULT)) < 0) {
        parallel_print("Cannot open dataset <%s>\n", obj1_name);
        HGOTO_ERROR(1, H5E_tools_min_id_g, "H5Dopen2 first dataset failed");
    }
    if((did2 = H5Dopen2(file2_id, obj2_name, H5P_DEFAULT)) < 0) {
        parallel_print("Cannot open dataset <%s>\n", obj2_name);
        HGOTO_ERROR(1, H5E_tools_min_id_g, "H5Dopen2 second dataset failed");
    }

    if((dcpl1 = H5Dget_create_plist(did1)) < 0)
        HGOTO_ERROR(1, H5E_tools_min_id_g, "H5Dget_create_plist first dataset failed");
    if((dcpl2 = H5Dget_create_plist(did2)) < 0)
        HGOTO_ERROR(1, H5E_tools_min_id_g, "H5Dget_create_plist second dataset failed");

    /*-------------------------------------------------------------------------
     * check if the dataset creation property list has filters that
     * are not registered in the current configuration
     * 1) the external filters GZIP and SZIP might not be available
     * 2) the internal filters might be turned off
     *-------------------------------------------------------------------------
     */
    if ((status = h5tools_canreadf((opts->m_verbose ? obj1_name : NULL), dcpl1) == 1) &&
            (status = h5tools_canreadf((opts->m_verbose ? obj2_name : NULL), dcpl2) == 1))
        nfound = diff_datasetid(did1, did2, obj1_name, obj2_name, opts);
    else if (status < 0) {
        HGOTO_ERROR(1, H5E_tools_min_id_g, "h5tools_canreadf failed");
    }
    else {
        ret_value = 1;
        opts->not_cmp = 1;
    }

done:
    opts->err_stat = opts->err_stat | ret_value;

    /* disable error reporting */
    H5E_BEGIN_TRY {
        H5Pclose(dcpl1);
        H5Pclose(dcpl2);
        H5Dclose(did1);
        H5Dclose(did2);
        /* enable error reporting */
    } H5E_END_TRY;

    h5diffdebug3("diff_dataset finish:%d - errstat:%d\n", nfound, opts->err_stat);
    return nfound;
}

/*-------------------------------------------------------------------------
 * Function: diff_datasetid
 *
 * Purpose: check for comparable datasets and read into a compatible
 *  memory type
 *
 * Return: Number of differences found
 *
 * October 2006:  Read by hyperslabs for big datasets.
 *
 *  A threshold of H5TOOLS_MALLOCSIZE (128 MB) is the limit upon which I/O hyperslab is done
 *  i.e., if the memory needed to read a dataset is greater than this limit,
 *  then hyperslab I/O is done instead of one operation I/O
 *  For each dataset, the memory needed is calculated according to
 *
 *  memory needed = number of elements * size of each element
 *
 *  if the memory needed is lower than H5TOOLS_MALLOCSIZE, then the following operations
 *  are done
 *
 *  H5Dread( input_dataset1 )
 *  H5Dread( input_dataset2 )
 *
 *  with all elements in the datasets selected. If the memory needed is greater than
 *  H5TOOLS_MALLOCSIZE, then the following operations are done instead:
 *
 *  a strip mine is defined for each dimension k (a strip mine is defined as a
 *  hyperslab whose size is memory manageable) according to the formula
 *
 *  (1) strip_mine_size[k ] = MIN(dimension[k ], H5TOOLS_BUFSIZE / size of memory type)
 *
 *  where H5TOOLS_BUFSIZE is a constant currently defined as 1MB. This formula assures
 *  that for small datasets (small relative to the H5TOOLS_BUFSIZE constant), the strip
 *  mine size k is simply defined as its dimension k, but for larger datasets the
 *  hyperslab size is still memory manageable.
 *  a cycle is done until the number of elements in the dataset is reached. In each
 *  iteration, two parameters are defined for the function H5Sselect_hyperslab,
 *  the start and size of each hyperslab, according to
 *
 *  (2) hyperslab_size [k] = MIN(dimension[k] - hyperslab_offset[k], strip_mine_size [k])
 *
 *  where hyperslab_offset [k] is initially set to zero, and later incremented in
 *  hyperslab_size[k] offsets. The reason for the operation
 *
 *  dimension[k] - hyperslab_offset[k]
 *
 *  in (2) is that, when using the strip mine size, it assures that the "remaining" part
 *  of the dataset that does not fill an entire strip mine is processed.
 *
 *-------------------------------------------------------------------------
 */
hsize_t diff_datasetid(hid_t did1,
                       hid_t did2,
                       const char *obj1_name,
                       const char *obj2_name,
                       diff_opt_t *opts)
{
    int        ret_value = opts->err_stat;
    hid_t      sid1 = -1;
    hid_t      sid2 = -1;
    hid_t      f_tid1 = -1;
    hid_t      f_tid2 = -1;
    hid_t      dam_tid = -1;             /* m_tid for diff_array function */
    hid_t      m_tid1 = -1;
    hid_t      m_tid2 = -1;
    hid_t      dcpl1 = -1;
    hid_t      dcpl2 = -1;
    H5D_layout_t     stl1 = -1;
    H5D_layout_t     stl2 = -1;
    size_t     dam_size;                /* m_size for diff_array function */
    size_t     m_size1;
    size_t     m_size2;
    H5T_sign_t sign1;
    H5T_sign_t sign2;
    int        rank1;
    int        rank2;
    hsize_t    danelmts;                /* nelmts for diff_array function */
    hsize_t    nelmts1;
    hsize_t    nelmts2;
    hsize_t    *dadims;                 /* dims for diff_array function */
    hsize_t    dims1[H5S_MAX_RANK];
    hsize_t    dims2[H5S_MAX_RANK];
    hsize_t    maxdim1[H5S_MAX_RANK];
    hsize_t    maxdim2[H5S_MAX_RANK];
    const char *name1 = NULL;           /* relative names */
    const char *name2 = NULL;
    hsize_t    storage_size1;
    hsize_t    storage_size2;
    hsize_t    nfound = 0;              /* number of differences found */
    int        can_compare = 1;         /* do diff or not */
    void       *buf1 = NULL;
    void       *buf2 = NULL;
    void       *sm_buf1 = NULL;
    void       *sm_buf2 = NULL;
    hid_t      sm_space;                /*stripmine data space */
    size_t     need;                    /* bytes needed for malloc */
    int        i;
    unsigned int  vl_data = 0;          /*contains VL datatypes */

    h5difftrace("diff_datasetid start\n");
    /* Get the dataspace handle */
    if((sid1 = H5Dget_space(did1)) < 0)
        HGOTO_ERROR(1, H5E_tools_min_id_g, "H5Dget_space failed");

    /* Get rank */
    if((rank1 = H5Sget_simple_extent_ndims(sid1)) < 0)
        HGOTO_ERROR(1, H5E_tools_min_id_g, "H5Sget_simple_extent_ndims failed");

    /* Get the dataspace handle */
    if((sid2 = H5Dget_space(did2)) < 0 )
        HGOTO_ERROR(1, H5E_tools_min_id_g, "H5Dget_space failed");

    /* Get rank */
    if((rank2 = H5Sget_simple_extent_ndims(sid2)) < 0)
        HGOTO_ERROR(1, H5E_tools_min_id_g, "H5Sget_simple_extent_ndims failed");

    /* Get dimensions */
    if(H5Sget_simple_extent_dims(sid1, dims1, maxdim1) < 0)
        HGOTO_ERROR(1, H5E_tools_min_id_g, "H5Sget_simple_extent_dims failed");

    /* Get dimensions */
    if(H5Sget_simple_extent_dims(sid2, dims2, maxdim2) < 0)
        HGOTO_ERROR(FAIL, H5E_tools_min_id_g, "H5Sget_simple_extent_dims failed");
    h5diffdebug3("rank: %ld - %ld\n", rank1, rank2);

    /*-------------------------------------------------------------------------
     * get the file data type
     *-------------------------------------------------------------------------
     */

    /* Get the data type */
    if((f_tid1 = H5Dget_type(did1)) < 0)
        HGOTO_ERROR(1, H5E_tools_min_id_g, "H5Dget_type failed");

    /* Get the data type */
    if((f_tid2 = H5Dget_type(did2)) < 0)
        HGOTO_ERROR(1, H5E_tools_min_id_g, "H5Dget_type failed");

    /*-------------------------------------------------------------------------
     * get the storage layout type
     *-------------------------------------------------------------------------
     */
    if((dcpl1 = H5Dget_create_plist(did1)) < 0)
        HGOTO_ERROR(1, H5E_tools_min_id_g, "H5Dget_create_plist failed");
    if((dcpl2 = H5Dget_create_plist(did2)) < 0)
        HGOTO_ERROR(1, H5E_tools_min_id_g, "H5Dget_create_plist failed");

    if((stl1 = H5Pget_layout(dcpl1)) < 0)
        HGOTO_ERROR(1, H5E_tools_min_id_g, "H5Pget_layout failed");
    if((stl2 = H5Pget_layout(dcpl2)) < 0)
        HGOTO_ERROR(1, H5E_tools_min_id_g, "H5Pget_layout failed");

    /*-------------------------------------------------------------------------
     * check for empty datasets
     *-------------------------------------------------------------------------
     */
    h5difftrace("check for empty datasets\n");

    storage_size1 = H5Dget_storage_size(did1);
    storage_size2 = H5Dget_storage_size(did2);
    h5diffdebug3("storage size: %ld - %ld\n", storage_size1, storage_size2);

    if(storage_size1 == 0 || storage_size2 == 0) {
        if(stl1 == H5D_VIRTUAL || stl2 == H5D_VIRTUAL) {
            if((opts->m_verbose||opts->m_list_not_cmp) && obj1_name && obj2_name)
                parallel_print("Warning: <%s> or <%s> is a virtual dataset\n", obj1_name, obj2_name);
        }
        else {
            if((opts->m_verbose || opts->m_list_not_cmp) && obj1_name && obj2_name)
                parallel_print("Not comparable: <%s> or <%s> is an empty dataset\n", obj1_name, obj2_name);
            can_compare = 0;
            opts->not_cmp = 1;
        }
    }

    /*-------------------------------------------------------------------------
     * check for comparable TYPE and SPACE
     *-------------------------------------------------------------------------
     */
    if (diff_can_type(f_tid1, f_tid2, rank1, rank2,
            dims1, dims2, maxdim1, maxdim2,
            obj1_name, obj2_name,
            opts, 0) != 1)
        can_compare = 0;
    h5diffdebug2("diff_can_type - errstat:%d\n", opts->err_stat);

    /*-------------------------------------------------------------------------
     * memory type and sizes
     *-------------------------------------------------------------------------
     */
    h5difftrace("check for memory type and sizes\n");
    if((m_tid1 = H5Tget_native_type(f_tid1, H5T_DIR_DEFAULT)) < 0)
        HGOTO_ERROR(1, H5E_tools_min_id_g, "H5Tget_native_type failed");

    if((m_tid2 = H5Tget_native_type(f_tid2, H5T_DIR_DEFAULT)) < 0)
        HGOTO_ERROR(1, H5E_tools_min_id_g, "H5Tget_native_type failed");

    m_size1 = H5Tget_size(m_tid1);
    m_size2 = H5Tget_size(m_tid2);
    h5diffdebug3("type size: %ld - %ld\n", m_size1, m_size2);

    /*-------------------------------------------------------------------------
     * check for different signed/unsigned types
     *-------------------------------------------------------------------------
     */
    if(can_compare) {
        h5difftrace("can_compare for sign\n");
        sign1 = H5Tget_sign(m_tid1);
        sign2 = H5Tget_sign(m_tid2);
        if(sign1 != sign2) {
            h5difftrace("sign1 != sign2\n");
            if((opts->m_verbose || opts->m_list_not_cmp) && obj1_name && obj2_name) {
                parallel_print("Not comparable: <%s> has sign %s ", obj1_name, get_sign(sign1));
                parallel_print("and <%s> has sign %s\n", obj2_name, get_sign(sign2));
            }

            can_compare = 0;
            opts->not_cmp = 1;
        }
    }

    /* Check if type is either VLEN-data or VLEN-string to reclaim any
     * VLEN memory buffer later
     */
    if(TRUE == h5tools_detect_vlen(m_tid1))
        vl_data = TRUE;
    h5diffdebug2("h5tools_detect_vlen - errstat:%d\n", opts->err_stat);

    /*------------------------------------------------------------------------
     * only attempt to compare if possible
     *-------------------------------------------------------------------------
     */
    if(can_compare) { /* it is possible to compare */
        H5T_class_t  tclass = H5Tget_class(f_tid1);
        h5difftrace("can_compare attempt\n");

        /*-----------------------------------------------------------------
        * get number of elements
        *------------------------------------------------------------------
        */
        nelmts1 = 1;
        for(i = 0; i < rank1; i++)
            nelmts1 *= dims1[i];

        nelmts2 = 1;
        for(i = 0; i < rank2; i++)
            nelmts2 *= dims2[i];

        h5diffdebug3("nelmts: %ld - %ld\n", nelmts1, nelmts2);

        if(tclass != H5T_ARRAY) {
            /*-----------------------------------------------------------------
             * "upgrade" the smaller memory size
             *------------------------------------------------------------------
             */
            h5difftrace("upgrade the smaller memory size?\n");
            if (FAIL == match_up_memsize (f_tid1, f_tid2,
                                        &m_tid1, &m_tid2,
                                        &m_size1, &m_size2))
                HGOTO_ERROR(1, H5E_tools_min_id_g, "match_up_memsize failed");
            h5diffdebug3("m_size: %ld - %ld\n", m_size1, m_size2);
            dadims = dims1;
            dam_size = m_size1;
            dam_tid = m_tid1;
            danelmts = nelmts1;
            need = (size_t)(nelmts1 * m_size1);  /* bytes needed */
        }
        else {
            h5diffdebug3("Array dims: %d - %d\n", dims1[0], dims2[0]);
            /* Compare the smallest array, but create the largest buffer */
            if(m_size1 <= m_size2) {
                dadims = dims1;
                dam_size = m_size1;
                dam_tid = m_tid1;
                danelmts = nelmts1;
                need = (size_t)(nelmts2 * m_size2);  /* bytes needed */
            }
            else {
                dadims = dims2;
                dam_size = m_size2;
                dam_tid = m_tid2;
                danelmts = nelmts2;
                need = (size_t)(nelmts1 * m_size1);  /* bytes needed */
            }
        }
        /* print names */
        if(obj1_name)
            name1 = diff_basename(obj1_name);
        if(obj2_name)
            name2 = diff_basename(obj2_name);
        h5diffdebug3("obj_names: %s - %s\n", name1, name2);


        /*----------------------------------------------------------------
         * read/compare
         *-----------------------------------------------------------------
         */
        if(need < H5TOOLS_MALLOCSIZE) {
            buf1 = HDmalloc(need);
            buf2 = HDmalloc(need);
        } /* end if */

        if(buf1 != NULL && buf2 != NULL) {
            h5difftrace("buf1 != NULL && buf2 != NULL\n");
            if(H5Dread(did1, m_tid1, H5S_ALL, H5S_ALL, H5P_DEFAULT, buf1) < 0)
                HGOTO_ERROR(1, H5E_tools_min_id_g, "H5Dread failed");
            h5difftrace("H5Dread did2\n");
            if(H5Dread(did2, m_tid2, H5S_ALL, H5S_ALL, H5P_DEFAULT, buf2) < 0)
                HGOTO_ERROR(1, H5E_tools_min_id_g, "H5Dread failed");

            /* array diff */
            nfound = diff_array(buf1, buf2, danelmts, (hsize_t)0, rank1, dadims,
                opts, name1, name2, dam_tid, did1, did2);
            h5diffdebug2("diff_array nfound:%d\n", nfound);

            /* reclaim any VL memory, if necessary */
            if(vl_data) {
                h5difftrace("check vl_data\n");
                H5Dvlen_reclaim(m_tid1, sid1, H5P_DEFAULT, buf1);
                H5Dvlen_reclaim(m_tid2, sid2, H5P_DEFAULT, buf2);
            } /* end if */
            if(buf1 != NULL) {
                HDfree(buf1);
                buf1 = NULL;
            }
            if(buf2 != NULL) {
                HDfree(buf2);
                buf2 = NULL;
            }
        } /* end if */
        else { /* possibly not enough memory, read/compare by hyperslabs */
            size_t        p_type_nbytes = dam_size; /*size of memory type */
            hsize_t       p_nelmts = danelmts;      /*total selected elmts */
            hsize_t       elmtno;                  /*counter  */
            int           carry;                   /*counter carry value */

            /* stripmine info */
            hsize_t       sm_size[H5S_MAX_RANK];   /*stripmine size */
            hsize_t       sm_nbytes;               /*bytes per stripmine */
            hsize_t       sm_nelmts;               /*elements per stripmine*/

            /* hyperslab info */
            hsize_t       hs_offset[H5S_MAX_RANK]; /*starting offset */
            hsize_t       hs_size[H5S_MAX_RANK];   /*size this pass */
            hsize_t       hs_nelmts;               /*elements in request */
            hsize_t       zero[8];                 /*vector of zeros */

            /*
             * determine the strip mine size and allocate a buffer. The strip mine is
             * a hyperslab whose size is manageable.
             */
            sm_nbytes = p_type_nbytes;

            for(i = rank1; i > 0; --i) {
                hsize_t size = H5TOOLS_BUFSIZE / sm_nbytes;

                if(size == 0) /* datum size > H5TOOLS_BUFSIZE */
                    size = 1;
                sm_size[i - 1] = MIN(dadims[i - 1], size);
                sm_nbytes *= sm_size[i - 1];
                h5diffdebug2("sm_nbytes: %ld\n", sm_nbytes);
            } /* end for */

            /* malloc return code should be verified.
             * If fail, need to handle the error.
             * This else branch should be recoded as a separate function.
             * Note that there are many "goto error" within this branch
             * that fails to address freeing other objects created here.
             * E.g., sm_space.
             */
            if((sm_buf1 = HDmalloc((size_t)sm_nbytes)) == NULL)
                HGOTO_ERROR(1, H5E_tools_min_id_g, "HDmalloc failed");
            if((sm_buf2 = HDmalloc((size_t)sm_nbytes)) == NULL)
                HGOTO_ERROR(1, H5E_tools_min_id_g, "HDmalloc failed");

            sm_nelmts = sm_nbytes / p_type_nbytes;
            sm_space = H5Screate_simple(1, &sm_nelmts, NULL);

            /* the stripmine loop */
            HDmemset(hs_offset, 0, sizeof hs_offset);
            HDmemset(zero, 0, sizeof zero);

            for(elmtno = 0; elmtno < p_nelmts; elmtno += hs_nelmts) {
                /* calculate the hyperslab size */
                if(rank1 > 0) {
                    for(i = 0, hs_nelmts = 1; i < rank1; i++) {
                        hs_size[i] = MIN(dadims[i] - hs_offset[i], sm_size[i]);
                        hs_nelmts *= hs_size[i];
                    } /* end for */
                    if(H5Sselect_hyperslab(sid1, H5S_SELECT_SET, hs_offset, NULL, hs_size, NULL) < 0)
                        HGOTO_ERROR(1, H5E_tools_min_id_g, "H5Sselect_hyperslab failed");
                    if(H5Sselect_hyperslab(sid2, H5S_SELECT_SET, hs_offset, NULL, hs_size, NULL) < 0)
                        HGOTO_ERROR(1, H5E_tools_min_id_g, "H5Sselect_hyperslab failed");
                    if(H5Sselect_hyperslab(sm_space, H5S_SELECT_SET, zero, NULL, &hs_nelmts, NULL) < 0)
                        HGOTO_ERROR(1, H5E_tools_min_id_g, "H5Sselect_hyperslab failed");
                } /* end if */
                else
                    hs_nelmts = 1;

                if(H5Dread(did1, m_tid1, sm_space, sid1, H5P_DEFAULT, sm_buf1) < 0)
                    HGOTO_ERROR(1, H5E_tools_min_id_g, "H5Dread failed");
                if(H5Dread(did2, m_tid2, sm_space, sid2, H5P_DEFAULT, sm_buf2) < 0)
                    HGOTO_ERROR(1, H5E_tools_min_id_g, "H5Dread failed");

                /* get array differences. in the case of hyperslab read, increment the number of differences
                found in each hyperslab and pass the position at the beginning for printing */
                nfound += diff_array(sm_buf1, sm_buf2, hs_nelmts, elmtno, rank1,
                        dadims, opts, name1, name2, dam_tid, did1, did2);

                /* reclaim any VL memory, if necessary */
                if(vl_data) {
                    H5Dvlen_reclaim(m_tid1, sm_space, H5P_DEFAULT, sm_buf1);
                    H5Dvlen_reclaim(m_tid1, sm_space, H5P_DEFAULT, sm_buf2);
                } /* end if */

                /* calculate the next hyperslab offset */
                for(i = rank1, carry = 1; i > 0 && carry; --i) {
                    hs_offset[i - 1] += hs_size[i - 1];
                    if(hs_offset[i - 1] == dadims[i - 1])
                        hs_offset[i - 1] = 0;
                    else
                        carry = 0;
                } /* i */
            } /* elmtno */
            if(sm_buf1 != NULL) {
                HDfree(sm_buf1);
                sm_buf1 = NULL;
            }
            if(sm_buf2 != NULL) {
                HDfree(sm_buf2);
                sm_buf2 = NULL;
            }

            H5Sclose(sm_space);
        } /* hyperslab read */
    } /*can_compare*/


    /*-------------------------------------------------------------------------
     * close
     *-------------------------------------------------------------------------
     */
    h5diffdebug2("reclaim any VL memory - errstat:%d\n", opts->err_stat);

done:
    opts->err_stat = opts->err_stat | ret_value;

    /* free */
    if(buf1 != NULL) {
        /* reclaim any VL memory, if necessary */
        if(vl_data)
            H5Dvlen_reclaim(m_tid1, sid1, H5P_DEFAULT, buf1);
        HDfree(buf1);
        buf1 = NULL;
    }
    if(buf2 != NULL) {
        /* reclaim any VL memory, if necessary */
        if(vl_data)
            H5Dvlen_reclaim(m_tid2, sid2, H5P_DEFAULT, buf2);
        HDfree(buf2);
        buf2 = NULL;
    }
    if(sm_buf1 != NULL) {
        /* reclaim any VL memory, if necessary */
        if(vl_data)
            H5Dvlen_reclaim(m_tid1, sm_space, H5P_DEFAULT, sm_buf1);
        HDfree(sm_buf1);
        sm_buf1 = NULL;
    }
    if(sm_buf2 != NULL) {
        /* reclaim any VL memory, if necessary */
        if(vl_data)
            H5Dvlen_reclaim(m_tid1, sm_space, H5P_DEFAULT, sm_buf2);
        HDfree(sm_buf2);
        sm_buf2 = NULL;
    }

    /* disable error reporting */
    H5E_BEGIN_TRY {
        H5Sclose(sid1);
        H5Sclose(sid2);
        H5Tclose(f_tid1);
        H5Tclose(f_tid2);
        H5Tclose(m_tid1);
        H5Tclose(m_tid2);
        /* enable error reporting */
    } H5E_END_TRY;

    h5diffdebug3("diff_datasetid return:%d with nfound:%d\n", ret_value, nfound);
    return nfound;
}

/*-------------------------------------------------------------------------
 * Function: diff_can_type
 *
 * Purpose:  check for comparable TYPE and SPACE
 *
 * Return:
 *           1, can compare
 *           0, cannot compare
 *          -1, error
 *-------------------------------------------------------------------------
 */

int diff_can_type(hid_t       f_tid1, /* file data type */
                  hid_t       f_tid2, /* file data type */
                  int         rank1,
                  int         rank2,
                  hsize_t     *dims1,
                  hsize_t     *dims2,
                  hsize_t     *maxdim1,
                  hsize_t     *maxdim2,
                  const char  *obj1_name,
                  const char  *obj2_name,
                  diff_opt_t  *opts,
                  int         is_compound)
{
    int          ret_value = 1;            /* can_compare value */
    H5T_class_t  tclass1;
    H5T_class_t  tclass2;
    int          maxdim_diff = 0;          /* maximum dimensions are different */
    int          dim_diff = 0;             /* current dimensions are different */
    int          i;

    h5difftrace("diff_can_type start\n");
    /*-------------------------------------------------------------------------
     * check for the same class
     *-------------------------------------------------------------------------
     */
    if((tclass1 = H5Tget_class(f_tid1)) < 0)
        HGOTO_ERROR(FAIL, H5E_tools_min_id_g, "H5Tget_class first object failed");
    if((tclass2 = H5Tget_class(f_tid2)) < 0)
        HGOTO_ERROR(FAIL, H5E_tools_min_id_g, "H5Tget_class second object failed");

    if(tclass1 != tclass2) {
        if((opts->m_verbose || opts->m_list_not_cmp) && obj1_name && obj2_name) {
            if(is_compound) {
                parallel_print("Not comparable: <%s> has a class %s and <%s> has a class %s\n",
                        obj1_name, get_class(tclass1),
                        obj2_name, get_class(tclass2));
            }
            else {
                parallel_print("Not comparable: <%s> is of class %s and <%s> is of class %s\n",
                        obj1_name, get_class(tclass1),
                        obj2_name, get_class(tclass2));
            }
        }
        opts->not_cmp = 1;
        HGOTO_DONE(0);
    }

    /*-------------------------------------------------------------------------
     * check for non supported classes
     *-------------------------------------------------------------------------
     */
    switch (tclass1) {
        case H5T_TIME:
            if((opts->m_verbose || opts->m_list_not_cmp) && obj1_name && obj2_name) {
                parallel_print("Not comparable: <%s> and <%s> are of class %s\n",
                        obj1_name, obj2_name, get_class(tclass2));
            } /* end if */
            opts->not_cmp = 1;
            HGOTO_DONE(0);

        case H5T_INTEGER:
        case H5T_FLOAT:
        case H5T_COMPOUND:
        case H5T_STRING:
        case H5T_ARRAY:
        case H5T_BITFIELD:
        case H5T_OPAQUE:
        case H5T_ENUM:
        case H5T_VLEN:
        case H5T_REFERENCE:
        case H5T_NO_CLASS:
        case H5T_NCLASSES:
        default:
            h5diffdebug2("diff_can_type class - %s\n", get_class(tclass1));
            break;
    } /* end switch */

    /*-------------------------------------------------------------------------
     * check for equal file datatype; warning only
     *-------------------------------------------------------------------------
     */
    if((H5Tequal(f_tid1, f_tid2) == 0) && (opts->m_verbose) && obj1_name && obj2_name) {
        H5T_class_t cl = H5Tget_class(f_tid1);

        parallel_print("Warning: different storage datatype\n");
        if(cl == H5T_INTEGER || cl == H5T_FLOAT) {
            parallel_print("<%s> has file datatype ", obj1_name);
            print_type(f_tid1);
            parallel_print("\n");
            parallel_print("<%s> has file datatype ", obj2_name);
            print_type(f_tid2);
            parallel_print("\n");
        }
    }

    /*-------------------------------------------------------------------------
     * check for the same rank
     *-------------------------------------------------------------------------
     */
    if(rank1 != rank2) {
        if((opts->m_verbose || opts->m_list_not_cmp) && obj1_name && obj2_name) {
            parallel_print("Not comparable: <%s> has rank %d, dimensions ", obj1_name, rank1);
            print_dimensions(rank1, dims1);
            parallel_print(", max dimensions ");
            print_dimensions(rank1, maxdim1);
            parallel_print("\n" );
            parallel_print("and <%s> has rank %d, dimensions ", obj2_name, rank2);
            print_dimensions(rank2, dims2);
            parallel_print(", max dimensions ");
            print_dimensions(rank2, maxdim2);
            parallel_print("\n");
        }
        opts->not_cmp = 1;
        HGOTO_DONE(0);
    }

    /*-------------------------------------------------------------------------
     * check for different dimensions
     *-------------------------------------------------------------------------
     */
    for(i = 0; i<rank1; i++) {
        if(maxdim1 && maxdim2) {
            if(maxdim1[i] != maxdim2[i])
                maxdim_diff = 1;
        }
        if(dims1[i] != dims2[i])
            dim_diff = 1;
    }

    /*-------------------------------------------------------------------------
     * current dimensions
     *-------------------------------------------------------------------------
     */
    if(dim_diff == 1) {
        if((opts->m_verbose || opts->m_list_not_cmp) && obj1_name && obj2_name) {
            parallel_print("Not comparable: <%s> has rank %d, dimensions ", obj1_name, rank1);
            print_dimensions(rank1, dims1);
            if(maxdim1 && maxdim2) {
                parallel_print(", max dimensions ");
                print_dimensions(rank1, maxdim1);
                parallel_print("\n" );
                parallel_print("and <%s> has rank %d, dimensions ", obj2_name, rank2);
                print_dimensions(rank2, dims2);
                parallel_print(", max dimensions ");
                print_dimensions(rank2, maxdim2);
                parallel_print("\n");
            }
        }
        opts->not_cmp = 1;
        HGOTO_DONE(0);
    }

    /*-------------------------------------------------------------------------
     * maximum dimensions; just give a warning
     *-------------------------------------------------------------------------
     */
    if(maxdim1 && maxdim2 && maxdim_diff == 1 && obj1_name) {
        if(opts->m_verbose) {
            parallel_print( "Warning: different maximum dimensions\n");
            parallel_print("<%s> has max dimensions ", obj1_name);
            print_dimensions(rank1, maxdim1);
            parallel_print("\n");
            parallel_print("<%s> has max dimensions ", obj2_name);
            print_dimensions(rank2, maxdim2);
            parallel_print("\n");
        }
    }

    if(tclass1 == H5T_COMPOUND) {
        int   nmembs1;
        int   nmembs2;
        int   j;
        hid_t memb_type1 = -1;
        hid_t memb_type2 = -1;

        nmembs1 = H5Tget_nmembers(f_tid1);
        nmembs2 = H5Tget_nmembers(f_tid2);

        if(nmembs1 != nmembs2) {
            if((opts->m_verbose || opts->m_list_not_cmp) && obj1_name && obj2_name) {
                parallel_print("Not comparable: <%s> has %d members ", obj1_name, nmembs1);
                parallel_print("<%s> has %d members ", obj2_name, nmembs2);
                parallel_print("\n");
            }
            opts->not_cmp = 1;
            HGOTO_DONE(0);
        }

        for (j = 0; j < nmembs1; j++) {
            memb_type1 = H5Tget_member_type(f_tid1, (unsigned)j);
            memb_type2 = H5Tget_member_type(f_tid2, (unsigned)j);

            if (diff_can_type(memb_type1, memb_type2, rank1, rank2,
                    dims1, dims2, maxdim1, maxdim2, obj1_name, obj2_name,
                    opts, 1) != 1) {
                opts->not_cmp = 1;
                H5Tclose(memb_type1);
                H5Tclose(memb_type2);
                HGOTO_DONE(0);
            }
            H5Tclose(memb_type1);
            H5Tclose(memb_type2);
        }
    }
done:
    if (ret_value < 0)
        opts->err_stat = 1;

    h5diffdebug2("diff_can_type end - %d\n", ret_value);
    return ret_value;
}


/*-------------------------------------------------------------------------
 * Function: print_sizes
 *
 * Purpose: Print datatype sizes
 *-------------------------------------------------------------------------
 */
#if defined (H5DIFF_DEBUG)
void print_sizes( const char *obj1,
                  const char *obj2,
                  hid_t f_tid1,
                  hid_t f_tid2,
                  hid_t m_tid1,
                  hid_t m_tid2 )
{
    size_t  f_size1, f_size2;       /* size of type in file */
    size_t  m_size1, m_size2;       /* size of type in memory */

    f_size1 = H5Tget_size( f_tid1 );
    f_size2 = H5Tget_size( f_tid2 );
    m_size1 = H5Tget_size( m_tid1 );
    m_size2 = H5Tget_size( m_tid2 );

    parallel_print("\n");
    parallel_print("------------------\n");
    parallel_print("sizeof(char)   %u\n", sizeof(char) );
    parallel_print("sizeof(short)  %u\n", sizeof(short) );
    parallel_print("sizeof(int)    %u\n", sizeof(int) );
    parallel_print("sizeof(long)   %u\n", sizeof(long) );
    parallel_print("<%s> ------------------\n", obj1);
    parallel_print("type on file   ");
    print_type(f_tid1);
    parallel_print("\n");
    parallel_print("size on file   %u\n", f_size1 );

    parallel_print("type on memory ");
    print_type(m_tid1);
    parallel_print("\n");
    parallel_print("size on memory %u\n", m_size1 );

    parallel_print("<%s> ------------------\n", obj2);
    parallel_print("type on file   ");
    print_type(f_tid2);
    parallel_print("\n");
    parallel_print("size on file   %u\n", f_size2 );

    parallel_print("type on memory ");
    print_type(m_tid2);
    parallel_print("\n");
    parallel_print("size on memory %u\n", m_size2 );
    parallel_print("\n");
}
#endif /* H5DIFF_DEBUG */