summaryrefslogtreecommitdiffstats
path: root/src/H5B2internal.c
blob: 6fe586f48402bf2a986d65feccbec9e2e1a8c536 (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
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
 * Copyright by The HDF Group.                                               *
 * All rights reserved.                                                      *
 *                                                                           *
 * This file is part of HDF5.  The full HDF5 copyright notice, including     *
 * terms governing use, modification, and redistribution, is contained in    *
 * the COPYING file, which can be found at the root of the source code       *
 * distribution tree, or in https://www.hdfgroup.org/licenses.               *
 * If you do not have access to either file, you may request a copy from     *
 * help@hdfgroup.org.                                                        *
 * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */

/*-------------------------------------------------------------------------
 *
 * Created:		H5B2internal.c
 *			Dec 01 2016
 *			Quincey Koziol
 *
 * Purpose:		Routines for managing v2 B-tree internal nodes.
 *
 *-------------------------------------------------------------------------
 */

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

#include "H5B2module.h" /* This source code file is part of the H5B2 module */

/***********/
/* Headers */
/***********/
#include "H5private.h"   /* Generic Functions			*/
#include "H5B2pkg.h"     /* v2 B-trees				*/
#include "H5Eprivate.h"  /* Error handling		  	*/
#include "H5MFprivate.h" /* File memory management		*/

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

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

/********************/
/* Package Typedefs */
/********************/

/********************/
/* Local Prototypes */
/********************/
static herr_t H5B2__shadow_internal(H5B2_internal_t *internal, H5B2_node_ptr_t *curr_node_ptr);

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

/* Declare a free list to manage the H5B2_internal_t struct */
H5FL_DEFINE(H5B2_internal_t);

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

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

/*-------------------------------------------------------------------------
 * Function:	H5B2__create_internal
 *
 * Purpose:	Creates empty internal node of a B-tree and update node pointer
 *              to point to it.
 *
 * Return:	Non-negative on success/Negative on failure
 *
 * Programmer:	Quincey Koziol
 *		Feb  3 2005
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5B2__create_internal(H5B2_hdr_t *hdr, void *parent, H5B2_node_ptr_t *node_ptr, uint16_t depth)
{
    H5B2_internal_t *internal  = NULL;    /* Pointer to new internal node created */
    hbool_t          inserted  = FALSE;   /* Whether the internal node was inserted into cache */
    herr_t           ret_value = SUCCEED; /* Return value */

    FUNC_ENTER_PACKAGE

    /* Check arguments. */
    HDassert(hdr);
    HDassert(node_ptr);
    HDassert(depth > 0);

    /* Allocate memory for internal node information */
    if (NULL == (internal = H5FL_CALLOC(H5B2_internal_t)))
        HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL, "memory allocation failed for B-tree internal info")

    /* Increment ref. count on B-tree header */
    if (H5B2__hdr_incr(hdr) < 0)
        HGOTO_ERROR(H5E_BTREE, H5E_CANTINC, FAIL, "can't increment ref. count on B-tree header")

    /* Share B-tree header information */
    internal->hdr = hdr;

    /* Allocate space for the native keys in memory */
    if (NULL == (internal->int_native = (uint8_t *)H5FL_FAC_MALLOC(hdr->node_info[depth].nat_rec_fac)))
        HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL,
                    "memory allocation failed for B-tree internal native keys")
    HDmemset(internal->int_native, 0, hdr->cls->nrec_size * hdr->node_info[depth].max_nrec);

    /* Allocate space for the node pointers in memory */
    if (NULL ==
        (internal->node_ptrs = (H5B2_node_ptr_t *)H5FL_FAC_MALLOC(hdr->node_info[depth].node_ptr_fac)))
        HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL,
                    "memory allocation failed for B-tree internal node pointers")
    HDmemset(internal->node_ptrs, 0, sizeof(H5B2_node_ptr_t) * (hdr->node_info[depth].max_nrec + 1));

    /* Set depth of the node */
    internal->depth = depth;

    /* Set parent */
    internal->parent = parent;

    /* Set shadowed epoch to header's epoch */
    internal->shadow_epoch = hdr->shadow_epoch;

    /* Allocate space on disk for the internal node */
    if (HADDR_UNDEF == (node_ptr->addr = H5MF_alloc(hdr->f, H5FD_MEM_BTREE, (hsize_t)hdr->node_size)))
        HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL, "file allocation failed for B-tree internal node")

    /* Cache the new B-tree node */
    if (H5AC_insert_entry(hdr->f, H5AC_BT2_INT, node_ptr->addr, internal, H5AC__NO_FLAGS_SET) < 0)
        HGOTO_ERROR(H5E_BTREE, H5E_CANTINIT, FAIL, "can't add B-tree internal node to cache")
    inserted = TRUE;

    /* Add internal node as child of 'top' proxy */
    if (hdr->top_proxy) {
        if (H5AC_proxy_entry_add_child(hdr->top_proxy, hdr->f, internal) < 0)
            HGOTO_ERROR(H5E_BTREE, H5E_CANTSET, FAIL, "unable to add v2 B-tree node as child of proxy")
        internal->top_proxy = hdr->top_proxy;
    } /* end if */

done:
    if (ret_value < 0) {
        if (internal) {
            /* Remove from cache, if inserted */
            if (inserted)
                if (H5AC_remove_entry(internal) < 0)
                    HDONE_ERROR(H5E_BTREE, H5E_CANTREMOVE, FAIL,
                                "unable to remove v2 B-tree internal node from cache")

            /* Release internal node's disk space */
            if (H5_addr_defined(node_ptr->addr) &&
                H5MF_xfree(hdr->f, H5FD_MEM_BTREE, node_ptr->addr, (hsize_t)hdr->node_size) < 0)
                HDONE_ERROR(H5E_BTREE, H5E_CANTFREE, FAIL,
                            "unable to release file space for v2 B-tree internal node")

            /* Destroy internal node */
            if (H5B2__internal_free(internal) < 0)
                HDONE_ERROR(H5E_BTREE, H5E_CANTFREE, FAIL, "unable to release v2 B-tree internal node")
        } /* end if */
    }     /* end if */

    FUNC_LEAVE_NOAPI(ret_value)
} /* H5B2__create_internal() */

/*-------------------------------------------------------------------------
 * Function:	H5B2__protect_internal
 *
 * Purpose:	"Protect" an internal node in the metadata cache
 *
 * Return:	Pointer to internal node on success/NULL on failure
 *
 * Programmer:	Quincey Koziol
 *		Aug 25 2006
 *
 *-------------------------------------------------------------------------
 */
H5B2_internal_t *
H5B2__protect_internal(H5B2_hdr_t *hdr, void *parent, H5B2_node_ptr_t *node_ptr, uint16_t depth,
                       hbool_t shadow, unsigned flags)
{
    H5B2_internal_cache_ud_t udata;            /* User data to pass through to cache 'deserialize' callback */
    H5B2_internal_t         *internal  = NULL; /* v2 B-tree internal node */
    H5B2_internal_t         *ret_value = NULL; /* Return value */

    FUNC_ENTER_PACKAGE

    /* Check arguments. */
    HDassert(hdr);
    HDassert(node_ptr);
    HDassert(H5_addr_defined(node_ptr->addr));
    HDassert(depth > 0);

    /* only H5AC__READ_ONLY_FLAG may appear in flags */
    HDassert((flags & (unsigned)(~H5AC__READ_ONLY_FLAG)) == 0);

    /* Set up user data for callback */
    udata.f      = hdr->f;
    udata.hdr    = hdr;
    udata.parent = parent;
    udata.nrec   = node_ptr->node_nrec;
    udata.depth  = depth;

    /* Protect the internal node */
    if (NULL ==
        (internal = (H5B2_internal_t *)H5AC_protect(hdr->f, H5AC_BT2_INT, node_ptr->addr, &udata, flags)))
        HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, NULL, "unable to protect B-tree internal node")

    /* Create top proxy, if it doesn't exist */
    if (hdr->top_proxy && NULL == internal->top_proxy) {
        /* Add internal node as child of 'top' proxy */
        if (H5AC_proxy_entry_add_child(hdr->top_proxy, hdr->f, internal) < 0)
            HGOTO_ERROR(H5E_BTREE, H5E_CANTSET, NULL,
                        "unable to add v2 B-tree internal node as child of proxy")
        internal->top_proxy = hdr->top_proxy;
    } /* end if */

    /* Shadow the node, if requested */
    if (shadow)
        if (H5B2__shadow_internal(internal, node_ptr) < 0)
            HGOTO_ERROR(H5E_BTREE, H5E_CANTCOPY, NULL, "unable to shadow internal node")

    /* Set return value */
    ret_value = internal;

done:
    /* Clean up on error */
    if (!ret_value) {
        /* Release the internal node, if it was protected */
        if (internal) {
            /* Remove from v2 B-tree's proxy, if added */
            if (internal->top_proxy) {
                if (H5AC_proxy_entry_remove_child(internal->top_proxy, internal) < 0)
                    HDONE_ERROR(
                        H5E_BTREE, H5E_CANTUNDEPEND, NULL,
                        "unable to destroy flush dependency between internal node and v2 B-tree 'top' proxy")
                internal->top_proxy = NULL;
            } /* end if */

            /* Unprotect internal node */
            if (H5AC_unprotect(hdr->f, H5AC_BT2_INT, node_ptr->addr, internal, H5AC__NO_FLAGS_SET) < 0)
                HDONE_ERROR(H5E_BTREE, H5E_CANTUNPROTECT, NULL,
                            "unable to unprotect v2 B-tree internal node, address = %llu",
                            (unsigned long long)node_ptr->addr)
        } /* end if */
    }     /* end if */

    FUNC_LEAVE_NOAPI(ret_value)
} /* H5B2__protect_internal() */

/*-------------------------------------------------------------------------
 * Function:	H5B2__neighbor_internal
 *
 * Purpose:	Locate a record relative to the specified information in a
 *              B-tree internal node and return that information by filling in
 *              fields of the
 *              caller-supplied UDATA pointer depending on the type of leaf node
 *		requested.  The UDATA can point to additional data passed
 *		to the key comparison function.
 *
 *              The 'OP' routine is called with the record found and the
 *              OP_DATA pointer, to allow caller to return information about
 *              the record.
 *
 *              The RANGE indicates whether to search for records less than or
 *              equal to, or greater than or equal to the information passed
 *              in with UDATA.
 *
 * Return:	Non-negative on success, negative on failure.
 *
 * Programmer:	Quincey Koziol
 *		Mar  9 2005
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5B2__neighbor_internal(H5B2_hdr_t *hdr, uint16_t depth, H5B2_node_ptr_t *curr_node_ptr, void *neighbor_loc,
                        H5B2_compare_t comp, void *parent, void *udata, H5B2_found_t op, void *op_data)
{
    H5B2_internal_t *internal;            /* Pointer to internal node */
    unsigned         idx       = 0;       /* Location of record which matches key */
    int              cmp       = 0;       /* Comparison value of records */
    herr_t           ret_value = SUCCEED; /* Return value */

    FUNC_ENTER_PACKAGE

    /* Check arguments. */
    HDassert(hdr);
    HDassert(depth > 0);
    HDassert(curr_node_ptr);
    HDassert(H5_addr_defined(curr_node_ptr->addr));
    HDassert(op);

    /* Lock current B-tree node */
    if (NULL ==
        (internal = H5B2__protect_internal(hdr, parent, curr_node_ptr, depth, FALSE, H5AC__READ_ONLY_FLAG)))
        HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to protect B-tree internal node")

    /* Locate node pointer for child */
    if (H5B2__locate_record(hdr->cls, internal->nrec, hdr->nat_off, internal->int_native, udata, &idx, &cmp) <
        0)
        HGOTO_ERROR(H5E_BTREE, H5E_CANTCOMPARE, FAIL, "can't compare btree2 records")
    if (cmp > 0)
        idx++;

    /* Set the neighbor location, if appropriate */
    if (comp == H5B2_COMPARE_LESS) {
        if (idx > 0)
            neighbor_loc = H5B2_INT_NREC(internal, hdr, idx - 1);
    } /* end if */
    else {
        HDassert(comp == H5B2_COMPARE_GREATER);

        if (idx < internal->nrec)
            neighbor_loc = H5B2_INT_NREC(internal, hdr, idx);
    } /* end else */

    /* Attempt to find neighboring record */
    if (depth > 1) {
        if (H5B2__neighbor_internal(hdr, (uint16_t)(depth - 1), &internal->node_ptrs[idx], neighbor_loc, comp,
                                    internal, udata, op, op_data) < 0)
            HGOTO_ERROR(H5E_BTREE, H5E_NOTFOUND, FAIL,
                        "unable to find neighbor record in B-tree internal node")
    } /* end if */
    else {
        if (H5B2__neighbor_leaf(hdr, &internal->node_ptrs[idx], neighbor_loc, comp, internal, udata, op,
                                op_data) < 0)
            HGOTO_ERROR(H5E_BTREE, H5E_NOTFOUND, FAIL, "unable to find neighbor record in B-tree leaf node")
    } /* end else */

done:
    /* Release the B-tree internal node */
    if (internal &&
        H5AC_unprotect(hdr->f, H5AC_BT2_INT, curr_node_ptr->addr, internal, H5AC__NO_FLAGS_SET) < 0)
        HDONE_ERROR(H5E_BTREE, H5E_CANTUNPROTECT, FAIL, "unable to release internal B-tree node")

    FUNC_LEAVE_NOAPI(ret_value)
} /* H5B2__neighbor_internal() */

/*-------------------------------------------------------------------------
 * Function:	H5B2__insert_internal
 *
 * Purpose:	Adds a new record to a B-tree node.
 *
 * Return:	Non-negative on success/Negative on failure
 *
 * Programmer:	Quincey Koziol
 *		Mar  2 2005
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5B2__insert_internal(H5B2_hdr_t *hdr, uint16_t depth, unsigned *parent_cache_info_flags_ptr,
                      H5B2_node_ptr_t *curr_node_ptr, H5B2_nodepos_t curr_pos, void *parent, void *udata)
{
    H5B2_internal_t *internal       = NULL; /* Pointer to internal node */
    unsigned         internal_flags = H5AC__NO_FLAGS_SET;
    unsigned         idx            = 0;               /* Location of record which matches key */
    H5B2_nodepos_t   next_pos       = H5B2_POS_MIDDLE; /* Position of node */
    herr_t           ret_value      = SUCCEED;         /* Return value */

    FUNC_ENTER_PACKAGE

    /* Check arguments. */
    HDassert(hdr);
    HDassert(depth > 0);
    HDassert(curr_node_ptr);
    HDassert(H5_addr_defined(curr_node_ptr->addr));

    /* Lock current B-tree node */
    if (NULL ==
        (internal = H5B2__protect_internal(hdr, parent, curr_node_ptr, depth, FALSE, H5AC__NO_FLAGS_SET)))
        HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to protect B-tree internal node")

    /* Sanity check number of records */
    HDassert(internal->nrec == curr_node_ptr->node_nrec);

    /* Split or redistribute child node pointers, if necessary */
    {
        int      cmp;        /* Comparison value of records */
        unsigned retries;    /* Number of times to attempt redistribution */
        size_t   split_nrec; /* Number of records to split node at */

        /* Locate node pointer for child */
        if (H5B2__locate_record(hdr->cls, internal->nrec, hdr->nat_off, internal->int_native, udata, &idx,
                                &cmp) < 0)
            HGOTO_ERROR(H5E_BTREE, H5E_CANTCOMPARE, FAIL, "can't compare btree2 records")
        if (cmp == 0)
            HGOTO_ERROR(H5E_BTREE, H5E_EXISTS, FAIL, "record is already in B-tree")
        if (cmp > 0)
            idx++;

        /* Set the number of redistribution retries */
        /* This takes care of the case where a B-tree node needs to be
         * redistributed, but redistributing the node causes the index
         * for insertion to move to another node, which also needs to be
         * redistributed.  Now, we loop trying to redistribute and then
         * eventually force a split */
        retries = 2;

        /* Determine the correct number of records to split child node at */
        split_nrec = hdr->node_info[depth - 1].split_nrec;

        /* Preemptively split/redistribute a node we will enter */
        while (internal->node_ptrs[idx].node_nrec == split_nrec) {
            /* Attempt to redistribute records among children */
            if (idx == 0) { /* Left-most child */
                if (retries > 0 && (internal->node_ptrs[idx + 1].node_nrec < split_nrec)) {
                    if (H5B2__redistribute2(hdr, depth, internal, idx) < 0)
                        HGOTO_ERROR(H5E_BTREE, H5E_CANTREDISTRIBUTE, FAIL,
                                    "unable to redistribute child node records")
                } /* end if */
                else {
                    if (H5B2__split1(hdr, depth, curr_node_ptr, parent_cache_info_flags_ptr, internal,
                                     &internal_flags, idx) < 0)
                        HGOTO_ERROR(H5E_BTREE, H5E_CANTSPLIT, FAIL, "unable to split child node")
                }                             /* end else */
            }                                 /* end if */
            else if (idx == internal->nrec) { /* Right-most child */
                if (retries > 0 && (internal->node_ptrs[idx - 1].node_nrec < split_nrec)) {
                    if (H5B2__redistribute2(hdr, depth, internal, (idx - 1)) < 0)
                        HGOTO_ERROR(H5E_BTREE, H5E_CANTREDISTRIBUTE, FAIL,
                                    "unable to redistribute child node records")
                } /* end if */
                else {
                    if (H5B2__split1(hdr, depth, curr_node_ptr, parent_cache_info_flags_ptr, internal,
                                     &internal_flags, idx) < 0)
                        HGOTO_ERROR(H5E_BTREE, H5E_CANTSPLIT, FAIL, "unable to split child node")
                }  /* end else */
            }      /* end if */
            else { /* Middle child */
                if (retries > 0 && ((internal->node_ptrs[idx + 1].node_nrec < split_nrec) ||
                                    (internal->node_ptrs[idx - 1].node_nrec < split_nrec))) {
                    if (H5B2__redistribute3(hdr, depth, internal, &internal_flags, idx) < 0)
                        HGOTO_ERROR(H5E_BTREE, H5E_CANTREDISTRIBUTE, FAIL,
                                    "unable to redistribute child node records")
                } /* end if */
                else {
                    if (H5B2__split1(hdr, depth, curr_node_ptr, parent_cache_info_flags_ptr, internal,
                                     &internal_flags, idx) < 0)
                        HGOTO_ERROR(H5E_BTREE, H5E_CANTSPLIT, FAIL, "unable to split child node")
                } /* end else */
            }     /* end else */

            /* Locate node pointer for child (after split/redistribute) */
            /* Actually, this can be easily updated (for 2-node redistrib.) and shouldn't require re-searching
             */
            if (H5B2__locate_record(hdr->cls, internal->nrec, hdr->nat_off, internal->int_native, udata, &idx,
                                    &cmp) < 0)
                HGOTO_ERROR(H5E_BTREE, H5E_CANTCOMPARE, FAIL, "can't compare btree2 records")
            if (cmp == 0)
                HGOTO_ERROR(H5E_BTREE, H5E_EXISTS, FAIL, "record is already in B-tree")
            if (cmp > 0)
                idx++;

            /* Decrement the number of redistribution retries left */
            retries--;
        } /* end while */
    }     /* end block */

    /* Check if this node is left/right-most */
    if (H5B2_POS_MIDDLE != curr_pos) {
        if (idx == 0) {
            if (H5B2_POS_LEFT == curr_pos || H5B2_POS_ROOT == curr_pos)
                next_pos = H5B2_POS_LEFT;
        } /* end if */
        else if (idx == internal->nrec) {
            if (H5B2_POS_RIGHT == curr_pos || H5B2_POS_ROOT == curr_pos)
                next_pos = H5B2_POS_RIGHT;
        } /* end else */
    }     /* end if */

    /* Attempt to insert node */
    if (depth > 1) {
        if (H5B2__insert_internal(hdr, (uint16_t)(depth - 1), &internal_flags, &internal->node_ptrs[idx],
                                  next_pos, internal, udata) < 0)
            HGOTO_ERROR(H5E_BTREE, H5E_CANTINSERT, FAIL, "unable to insert record into B-tree internal node")
    } /* end if */
    else {
        if (H5B2__insert_leaf(hdr, &internal->node_ptrs[idx], next_pos, internal, udata) < 0)
            HGOTO_ERROR(H5E_BTREE, H5E_CANTINSERT, FAIL, "unable to insert record into B-tree leaf node")
    } /* end else */

    /* Update record count for node pointer to current node */
    curr_node_ptr->all_nrec++;

    /* Mark node as dirty */
    internal_flags |= H5AC__DIRTIED_FLAG;

done:
    /* Release the B-tree internal node */
    if (internal) {
        /* Shadow the node if doing SWMR writes */
        if (hdr->swmr_write && (internal_flags & H5AC__DIRTIED_FLAG))
            if (H5B2__shadow_internal(internal, curr_node_ptr) < 0)
                HDONE_ERROR(H5E_BTREE, H5E_CANTCOPY, FAIL, "unable to shadow internal B-tree node")

        /* Unprotect node */
        if (H5AC_unprotect(hdr->f, H5AC_BT2_INT, curr_node_ptr->addr, internal, internal_flags) < 0)
            HDONE_ERROR(H5E_BTREE, H5E_CANTUNPROTECT, FAIL, "unable to release internal B-tree node")
    } /* end if */

    FUNC_LEAVE_NOAPI(ret_value)
} /* H5B2__insert_internal() */

/*-------------------------------------------------------------------------
 * Function:	H5B2__update_internal
 *
 * Purpose:	Insert or modify a record in a B-tree internal node.
 *		If the record exists already, it is modified as if H5B2_modify
 *		was called).  If it doesn't exist, it is inserted as if
 *		H5B2_insert was called.
 *
 * Return:	Non-negative on success/Negative on failure
 *
 * Programmer:	Quincey Koziol
 *		Dec 24 2015
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5B2__update_internal(H5B2_hdr_t *hdr, uint16_t depth, unsigned *parent_cache_info_flags_ptr,
                      H5B2_node_ptr_t *curr_node_ptr, H5B2_update_status_t *status, H5B2_nodepos_t curr_pos,
                      void *parent, void *udata, H5B2_modify_t op, void *op_data)
{
    H5B2_internal_t *internal       = NULL; /* Pointer to internal node */
    unsigned         internal_flags = H5AC__NO_FLAGS_SET;
    int              cmp;                         /* Comparison value of records */
    unsigned         idx       = 0;               /* Location of record which matches key */
    H5B2_nodepos_t   next_pos  = H5B2_POS_MIDDLE; /* Position of node */
    herr_t           ret_value = SUCCEED;         /* Return value */

    FUNC_ENTER_PACKAGE

    /* Check arguments. */
    HDassert(hdr);
    HDassert(depth > 0);
    HDassert(curr_node_ptr);
    HDassert(H5_addr_defined(curr_node_ptr->addr));

    /* Lock current B-tree node */
    if (NULL ==
        (internal = H5B2__protect_internal(hdr, parent, curr_node_ptr, depth, FALSE, H5AC__NO_FLAGS_SET)))
        HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to protect B-tree internal node")

    /* Sanity check number of records */
    HDassert(internal->nrec == curr_node_ptr->node_nrec);

    /* Locate node pointer for child */
    if (H5B2__locate_record(hdr->cls, internal->nrec, hdr->nat_off, internal->int_native, udata, &idx, &cmp) <
        0)
        HGOTO_ERROR(H5E_BTREE, H5E_CANTCOMPARE, FAIL, "can't compare btree2 records")

    /* Check for modifying existing record */
    if (0 == cmp) {
        hbool_t changed = FALSE; /* Whether the 'modify' callback changed the record */

        /* Make callback for current record */
        if ((op)(H5B2_INT_NREC(internal, hdr, idx), op_data, &changed) < 0) {
            /* Make certain that the callback didn't modify the value if it failed */
            HDassert(changed == FALSE);

            HGOTO_ERROR(H5E_BTREE, H5E_CANTMODIFY, FAIL,
                        "'modify' callback failed for B-tree update operation")
        } /* end if */

        /* Mark the node as dirty if it changed */
        internal_flags |= (changed ? H5AC__DIRTIED_FLAG : 0);

        /* Indicate that the record was modified */
        *status = H5B2_UPDATE_MODIFY_DONE;
    } /* end if */
    else {
        /* Adjust index to leave room for node to insert */
        if (cmp > 0)
            idx++;

        /* Check if this node is left/right-most */
        if (H5B2_POS_MIDDLE != curr_pos) {
            if (idx == 0) {
                if (H5B2_POS_LEFT == curr_pos || H5B2_POS_ROOT == curr_pos)
                    next_pos = H5B2_POS_LEFT;
            } /* end if */
            else if (idx == internal->nrec) {
                if (H5B2_POS_RIGHT == curr_pos || H5B2_POS_ROOT == curr_pos)
                    next_pos = H5B2_POS_RIGHT;
            } /* end else */
        }     /* end if */

        /* Attempt to update record in child */
        if (depth > 1) {
            if (H5B2__update_internal(hdr, (uint16_t)(depth - 1), &internal_flags, &internal->node_ptrs[idx],
                                      status, next_pos, internal, udata, op, op_data) < 0)
                HGOTO_ERROR(H5E_BTREE, H5E_CANTUPDATE, FAIL,
                            "unable to update record in internal B-tree node")
        } /* end if */
        else {
            if (H5B2__update_leaf(hdr, &internal->node_ptrs[idx], status, next_pos, internal, udata, op,
                                  op_data) < 0)
                HGOTO_ERROR(H5E_BTREE, H5E_CANTUPDATE, FAIL, "unable to update record in leaf B-tree node")
        } /* end else */

        /* Take actions based on child's status report */
        switch (*status) {
            case H5B2_UPDATE_MODIFY_DONE:
                /* No action */
                break;

            case H5B2_UPDATE_SHADOW_DONE:
                /* If child node was shadowed (if SWMR is enabled), mark this node dirty */
                if (hdr->swmr_write)
                    internal_flags |= H5AC__DIRTIED_FLAG;

                /* No further modifications up the tree are necessary though, so downgrade to merely
                 * "modified" */
                *status = H5B2_UPDATE_MODIFY_DONE;
                break;

            case H5B2_UPDATE_INSERT_DONE:
                /* Mark node as dirty */
                internal_flags |= H5AC__DIRTIED_FLAG;

                /* Update total record count for node pointer to current node */
                curr_node_ptr->all_nrec++;
                break;

            case H5B2_UPDATE_INSERT_CHILD_FULL:
                /* Split/redistribute this node */
                if (internal->nrec == hdr->node_info[depth].split_nrec) {
                    hbool_t could_split = FALSE; /* Whether the child node could split */

                    if (idx == 0) { /* Left-most child */
                        /* Check for left-most child and its neighbor being close to full */
                        if ((internal->node_ptrs[idx].node_nrec + internal->node_ptrs[idx + 1].node_nrec) >=
                            (unsigned)((hdr->node_info[depth - 1].split_nrec * 2) - 1))
                            could_split = TRUE;
                    }
                    else if (idx == internal->nrec) { /* Right-most child */
                        /* Check for right-most child and its neighbor being close to full */
                        if ((internal->node_ptrs[idx - 1].node_nrec + internal->node_ptrs[idx].node_nrec) >=
                            (unsigned)((hdr->node_info[depth - 1].split_nrec * 2) - 1))
                            could_split = TRUE;
                    }
                    else { /* Middle child */
                        /* Check for middle child and its left neighbor being close to full */
                        if ((internal->node_ptrs[idx - 1].node_nrec + internal->node_ptrs[idx].node_nrec) >=
                            (unsigned)((hdr->node_info[depth - 1].split_nrec * 2) - 1))
                            could_split = TRUE;
                        /* Check for middle child and its right neighbor being close to full */
                        else if ((internal->node_ptrs[idx].node_nrec +
                                  internal->node_ptrs[idx + 1].node_nrec) >=
                                 (unsigned)((hdr->node_info[depth - 1].split_nrec * 2) - 1))
                            could_split = TRUE;
                    }

                    /* If this node is full and the child node insertion could
                     *  cause a split, punt back up to caller, leaving the
                     *  "insert child full" status.
                     */
                    if (could_split) {
                        /* Release the internal B-tree node */
                        if (H5AC_unprotect(hdr->f, H5AC_BT2_INT, curr_node_ptr->addr, internal,
                                           internal_flags) < 0)
                            HGOTO_ERROR(H5E_BTREE, H5E_CANTUNPROTECT, FAIL,
                                        "unable to release internal B-tree node")
                        internal = NULL;

                        /* Punt back to caller */
                        HGOTO_DONE(SUCCEED);
                    }
                }

                /* Release the internal B-tree node */
                if (H5AC_unprotect(hdr->f, H5AC_BT2_INT, curr_node_ptr->addr, internal, internal_flags) < 0)
                    HGOTO_ERROR(H5E_BTREE, H5E_CANTUNPROTECT, FAIL, "unable to release internal B-tree node")
                internal = NULL;

                /* Indicate that the record was inserted */
                *status = H5B2_UPDATE_INSERT_DONE;

                /* Dodge sideways into inserting a record into this node */
                if (H5B2__insert_internal(hdr, depth, parent_cache_info_flags_ptr, curr_node_ptr, curr_pos,
                                          parent, udata) < 0)
                    HGOTO_ERROR(H5E_BTREE, H5E_CANTINSERT, FAIL,
                                "unable to insert record into internal B-tree node")
                break;

            case H5B2_UPDATE_UNKNOWN:
            default:
                HDassert(0 && "Invalid update status");
                HGOTO_ERROR(H5E_BTREE, H5E_CANTUPDATE, FAIL, "invalid update status")
        } /* end switch */
    }     /* end else */

done:
    /* Release the internal B-tree node */
    if (internal) {
        /* Check if we should shadow this node */
        if (hdr->swmr_write && (internal_flags & H5AC__DIRTIED_FLAG)) {
            /* Attempt to shadow the node if doing SWMR writes */
            if (H5B2__shadow_internal(internal, curr_node_ptr) < 0)
                HDONE_ERROR(H5E_BTREE, H5E_CANTCOPY, FAIL, "unable to shadow internal B-tree node")

            /* Change the state to "shadowed" if only modified currently */
            /* (Triggers parent to be marked dirty) */
            if (*status == H5B2_UPDATE_MODIFY_DONE)
                *status = H5B2_UPDATE_SHADOW_DONE;
        } /* end if */

        /* Unprotect node */
        if (H5AC_unprotect(hdr->f, H5AC_BT2_INT, curr_node_ptr->addr, internal, internal_flags) < 0)
            HDONE_ERROR(H5E_BTREE, H5E_CANTUNPROTECT, FAIL, "unable to release internal B-tree node")
    } /* end if */

    FUNC_LEAVE_NOAPI(ret_value)
} /* H5B2__update_internal() */

/*-------------------------------------------------------------------------
 * Function:    H5B2__shadow_internal
 *
 * Purpose:     "Shadow" an internal node - copy it to a new location,
 *              leaving the data in the old location intact (for now).
 *              This is done when writing in SWMR mode to ensure that
 *              readers do not see nodes that are out of date with
 *              respect to each other and thereby inconsistent.
 *
 * Return:      Non-negative on success/Negative on failure
 *
 * Programmer:  Neil Fortner
 *              Apr 27 2012
 *
 *-------------------------------------------------------------------------
 */
static herr_t
H5B2__shadow_internal(H5B2_internal_t *internal, H5B2_node_ptr_t *curr_node_ptr)
{
    H5B2_hdr_t *hdr;                 /* B-tree header */
    herr_t      ret_value = SUCCEED; /* Return value */

    FUNC_ENTER_PACKAGE

    /*
     * Check arguments.
     */
    HDassert(internal);
    HDassert(curr_node_ptr);
    HDassert(H5_addr_defined(curr_node_ptr->addr));
    hdr = internal->hdr;
    HDassert(hdr);
    HDassert(hdr->swmr_write);

    /* We only need to shadow the node if it has not been shadowed since the
     * last time the header was flushed, as otherwise it will be unreachable by
     * the readers so there will be no need to shadow.  To check if it has been
     * shadowed, compare the epoch of this node and the header.  If this node's
     * epoch is <= to the header's, it hasn't been shadowed yet. */
    if (internal->shadow_epoch <= hdr->shadow_epoch) {
        haddr_t new_node_addr; /* Address to move node to */

        /*
         * We must clone the old node so readers with an out-of-date version of
         * the parent can still see the correct number of children, via the
         * shadowed node.  Remove it from cache but do not mark it free on disk.
         */
        /* Allocate space for the cloned node */
        if (HADDR_UNDEF == (new_node_addr = H5MF_alloc(hdr->f, H5FD_MEM_BTREE, (hsize_t)hdr->node_size)))
            HGOTO_ERROR(H5E_BTREE, H5E_CANTALLOC, FAIL, "unable to allocate file space to move B-tree node")

        /* Move the location of the node on the disk */
        if (H5AC_move_entry(hdr->f, H5AC_BT2_INT, curr_node_ptr->addr, new_node_addr) < 0)
            HGOTO_ERROR(H5E_BTREE, H5E_CANTMOVE, FAIL, "unable to move B-tree node")
        curr_node_ptr->addr = new_node_addr;

        /* Should free the space in the file, but this is not supported by
         * SWMR_WRITE code yet - QAK, 2016/12/01
         */

        /* Set shadow epoch for node ahead of header */
        internal->shadow_epoch = hdr->shadow_epoch + 1;
    } /* end if */

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5B2__shadow_internal() */

/*-------------------------------------------------------------------------
 * Function:	H5B2__remove_internal
 *
 * Purpose:	Removes a record from a B-tree node.
 *
 * Return:	Non-negative on success/Negative on failure
 *
 * Programmer:	Quincey Koziol
 *		Mar  3 2005
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5B2__remove_internal(H5B2_hdr_t *hdr, hbool_t *depth_decreased, void *swap_loc, void *swap_parent,
                      uint16_t depth, H5AC_info_t *parent_cache_info, unsigned *parent_cache_info_flags_ptr,
                      H5B2_nodepos_t curr_pos, H5B2_node_ptr_t *curr_node_ptr, void *udata, H5B2_remove_t op,
                      void *op_data)
{
    H5AC_info_t     *new_cache_info; /* Pointer to new cache info */
    unsigned        *new_cache_info_flags_ptr = NULL;
    H5B2_node_ptr_t *new_node_ptr;                     /* Pointer to new node pointer */
    H5B2_internal_t *internal;                         /* Pointer to internal node */
    H5B2_nodepos_t   next_pos       = H5B2_POS_MIDDLE; /* Position of next node */
    unsigned         internal_flags = H5AC__NO_FLAGS_SET;
    haddr_t          internal_addr  = HADDR_UNDEF; /* Address of internal node */
    size_t           merge_nrec;                   /* Number of records to merge node at */
    hbool_t          collapsed_root = FALSE;       /* Whether the root was collapsed */
    herr_t           ret_value      = SUCCEED;     /* Return value */

    FUNC_ENTER_PACKAGE

    /* Check arguments. */
    HDassert(hdr);
    HDassert(depth > 0);
    HDassert(parent_cache_info);
    HDassert(curr_node_ptr);
    HDassert(H5_addr_defined(curr_node_ptr->addr));

    /* Lock current B-tree node */
    if (NULL == (internal = H5B2__protect_internal(hdr, parent_cache_info, curr_node_ptr, depth, FALSE,
                                                   H5AC__NO_FLAGS_SET)))
        HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to protect B-tree internal node")
    internal_addr = curr_node_ptr->addr;

    /* Determine the correct number of records to merge at */
    merge_nrec = hdr->node_info[depth - 1].merge_nrec;

    /* Check for needing to collapse the root node */
    /* (The root node is the only internal node allowed to have 1 record) */
    if (internal->nrec == 1 &&
        ((internal->node_ptrs[0].node_nrec + internal->node_ptrs[1].node_nrec) <= ((merge_nrec * 2) + 1))) {

        /* Merge children of root node */
        if (H5B2__merge2(hdr, depth, curr_node_ptr, parent_cache_info_flags_ptr, internal, &internal_flags,
                         0) < 0)
            HGOTO_ERROR(H5E_BTREE, H5E_CANTSPLIT, FAIL, "unable to merge child node")

        /* Let the cache know that the object is deleted */
        internal_flags |= H5AC__DELETED_FLAG;
        if (!hdr->swmr_write)
            internal_flags |= H5AC__FREE_FILE_SPACE_FLAG;

        /* Reset information in header's root node pointer */
        curr_node_ptr->addr      = internal->node_ptrs[0].addr;
        curr_node_ptr->node_nrec = internal->node_ptrs[0].node_nrec;

        /* Update flush dependency for child, if using SWMR */
        if (hdr->swmr_write)
            if (H5B2__update_flush_depend(hdr, depth, curr_node_ptr, internal, hdr) < 0)
                HGOTO_ERROR(H5E_BTREE, H5E_CANTUPDATE, FAIL, "unable to update child node to new parent")

        /* Indicate that the level of the B-tree decreased */
        *depth_decreased = TRUE;

        /* Set pointers for advancing to child node */
        new_cache_info           = parent_cache_info;
        new_cache_info_flags_ptr = parent_cache_info_flags_ptr;
        new_node_ptr             = curr_node_ptr;

        /* Set flag to indicate root was collapsed */
        collapsed_root = TRUE;

        /* Indicate position of next node */
        next_pos = H5B2_POS_ROOT;
    } /* end if */
    /* Merge or redistribute child node pointers, if necessary */
    else {
        unsigned idx = 0; /* Location of record which matches key */
        int      cmp = 0; /* Comparison value of records */
        unsigned retries; /* Number of times to attempt redistribution */

        /* Shadow the node if doing SWMR writes */
        if (hdr->swmr_write) {
            if (H5B2__shadow_internal(internal, curr_node_ptr) < 0)
                HGOTO_ERROR(H5E_BTREE, H5E_CANTCOPY, FAIL, "unable to shadow internal node")
            internal_addr = curr_node_ptr->addr;
        } /* end if */

        /* Locate node pointer for child */
        if (swap_loc)
            idx = 0;
        else {
            if (H5B2__locate_record(hdr->cls, internal->nrec, hdr->nat_off, internal->int_native, udata, &idx,
                                    &cmp) < 0)
                HGOTO_ERROR(H5E_BTREE, H5E_CANTCOMPARE, FAIL, "can't compare btree2 records")
            if (cmp >= 0)
                idx++;
        } /* end else */

        /* Set the number of redistribution retries */
        /* This takes care of the case where a B-tree node needs to be
         * redistributed, but redistributing the node causes the index
         * for removal to move to another node, which also needs to be
         * redistributed.  Now, we loop trying to redistribute and then
         * eventually force a merge */
        retries = 2;

        /* Preemptively merge/redistribute a node we will enter */
        while (internal->node_ptrs[idx].node_nrec == merge_nrec) {
            /* Attempt to redistribute records among children */
            /* (NOTE: These 2-node redistributions should actually get the
             *  record to promote from the node with more records. - QAK)
             */
            /* (NOTE: This code is the same in both H5B2__remove_internal() and
             *  H5B2__remove_internal_by_idx(), fix bugs in both places! - QAK)
             */
            if (idx == 0) { /* Left-most child */
                if (retries > 0 && (internal->node_ptrs[idx + 1].node_nrec > merge_nrec)) {
                    if (H5B2__redistribute2(hdr, depth, internal, idx) < 0)
                        HGOTO_ERROR(H5E_BTREE, H5E_CANTREDISTRIBUTE, FAIL,
                                    "unable to redistribute child node records")
                } /* end if */
                else {
                    if (H5B2__merge2(hdr, depth, curr_node_ptr, parent_cache_info_flags_ptr, internal,
                                     &internal_flags, idx) < 0)
                        HGOTO_ERROR(H5E_BTREE, H5E_CANTSPLIT, FAIL, "unable to merge child node")
                }                             /* end else */
            }                                 /* end if */
            else if (idx == internal->nrec) { /* Right-most child */
                if (retries > 0 && (internal->node_ptrs[idx - 1].node_nrec > merge_nrec)) {
                    if (H5B2__redistribute2(hdr, depth, internal, (idx - 1)) < 0)
                        HGOTO_ERROR(H5E_BTREE, H5E_CANTREDISTRIBUTE, FAIL,
                                    "unable to redistribute child node records")
                } /* end if */
                else {
                    if (H5B2__merge2(hdr, depth, curr_node_ptr, parent_cache_info_flags_ptr, internal,
                                     &internal_flags, (idx - 1)) < 0)
                        HGOTO_ERROR(H5E_BTREE, H5E_CANTSPLIT, FAIL, "unable to merge child node")
                }  /* end else */
            }      /* end if */
            else { /* Middle child */
                if (retries > 0 && ((internal->node_ptrs[idx + 1].node_nrec > merge_nrec) ||
                                    (internal->node_ptrs[idx - 1].node_nrec > merge_nrec))) {
                    if (H5B2__redistribute3(hdr, depth, internal, &internal_flags, idx) < 0)
                        HGOTO_ERROR(H5E_BTREE, H5E_CANTREDISTRIBUTE, FAIL,
                                    "unable to redistribute child node records")
                } /* end if */
                else {
                    if (H5B2__merge3(hdr, depth, curr_node_ptr, parent_cache_info_flags_ptr, internal,
                                     &internal_flags, idx) < 0)
                        HGOTO_ERROR(H5E_BTREE, H5E_CANTSPLIT, FAIL, "unable to merge child node")
                } /* end else */
            }     /* end else */

            /* Locate node pointer for child (after merge/redistribute) */
            if (swap_loc)
                idx = 0;
            else {
                /* Actually, this can be easily updated (for 2-node redistrib.) and shouldn't require
                 * re-searching */
                if (H5B2__locate_record(hdr->cls, internal->nrec, hdr->nat_off, internal->int_native, udata,
                                        &idx, &cmp) < 0)
                    HGOTO_ERROR(H5E_BTREE, H5E_CANTCOMPARE, FAIL, "can't compare btree2 records")
                if (cmp >= 0)
                    idx++;
            } /* end else */

            /* Decrement the number of redistribution retries left */
            retries--;
        } /* end while */

        /* Handle deleting a record from an internal node */
        if (!swap_loc && cmp == 0) {
            swap_loc    = H5B2_INT_NREC(internal, hdr, idx - 1);
            swap_parent = internal;
        } /* end if */

        /* Swap record to delete with record from leaf, if we are the last internal node */
        if (swap_loc && depth == 1)
            if (H5B2__swap_leaf(hdr, depth, internal, &internal_flags, idx, swap_loc) < 0)
                HGOTO_ERROR(H5E_BTREE, H5E_CANTSWAP, FAIL, "Can't swap records in B-tree")

        /* Set pointers for advancing to child node */
        new_cache_info_flags_ptr = &internal_flags;
        new_cache_info           = &internal->cache_info;
        new_node_ptr             = &internal->node_ptrs[idx];

        /* Indicate position of next node */
        if (H5B2_POS_MIDDLE != curr_pos) {
            if (idx == 0) {
                if (H5B2_POS_LEFT == curr_pos || H5B2_POS_ROOT == curr_pos)
                    next_pos = H5B2_POS_LEFT;
            } /* end if */
            else if (idx == internal->nrec) {
                if (H5B2_POS_RIGHT == curr_pos || H5B2_POS_ROOT == curr_pos)
                    next_pos = H5B2_POS_RIGHT;
            } /* end if */
        }     /* end if */
    }         /* end else */

    /* Attempt to remove record from child node */
    if (depth > 1) {
        if (H5B2__remove_internal(hdr, depth_decreased, swap_loc, swap_parent, (uint16_t)(depth - 1),
                                  new_cache_info, new_cache_info_flags_ptr, next_pos, new_node_ptr, udata, op,
                                  op_data) < 0)
            HGOTO_ERROR(H5E_BTREE, H5E_CANTDELETE, FAIL, "unable to remove record from B-tree internal node")
    } /* end if */
    else {
        if (H5B2__remove_leaf(hdr, new_node_ptr, next_pos, new_cache_info, udata, op, op_data) < 0)
            HGOTO_ERROR(H5E_BTREE, H5E_CANTDELETE, FAIL, "unable to remove record from B-tree leaf node")
    } /* end else */

    /* Update record count for node pointer to current node */
    if (!collapsed_root)
        new_node_ptr->all_nrec--;

    /* Mark node as dirty */
    if (!(hdr->swmr_write && collapsed_root))
        internal_flags |= H5AC__DIRTIED_FLAG;

#ifdef H5B2_DEBUG
    H5B2__assert_internal((!collapsed_root ? (curr_node_ptr->all_nrec - 1) : new_node_ptr->all_nrec), hdr,
                          internal);
#endif /* H5B2_DEBUG */

done:
    /* Release the B-tree internal node */
    if (internal && H5AC_unprotect(hdr->f, H5AC_BT2_INT, internal_addr, internal, internal_flags) < 0)
        HDONE_ERROR(H5E_BTREE, H5E_CANTUNPROTECT, FAIL, "unable to release internal B-tree node")

    FUNC_LEAVE_NOAPI(ret_value)
} /* H5B2__remove_internal() */

/*-------------------------------------------------------------------------
 * Function:	H5B2__remove_internal_by_idx
 *
 * Purpose:	Removes a record from a B-tree node, according to the offset
 *              in the B-tree records
 *
 * Return:	Non-negative on success/Negative on failure
 *
 * Programmer:	Quincey Koziol
 *		Nov 14 2006
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5B2__remove_internal_by_idx(H5B2_hdr_t *hdr, hbool_t *depth_decreased, void *swap_loc, void *swap_parent,
                             uint16_t depth, H5AC_info_t *parent_cache_info,
                             unsigned *parent_cache_info_flags_ptr, H5B2_node_ptr_t *curr_node_ptr,
                             H5B2_nodepos_t curr_pos, hsize_t n, H5B2_remove_t op, void *op_data)
{
    H5AC_info_t     *new_cache_info; /* Pointer to new cache info */
    unsigned        *new_cache_info_flags_ptr = NULL;
    H5B2_node_ptr_t *new_node_ptr;                     /* Pointer to new node pointer */
    H5B2_internal_t *internal;                         /* Pointer to internal node */
    H5B2_nodepos_t   next_pos       = H5B2_POS_MIDDLE; /* Position of next node */
    unsigned         internal_flags = H5AC__NO_FLAGS_SET;
    haddr_t          internal_addr  = HADDR_UNDEF; /* Address of internal node */
    size_t           merge_nrec;                   /* Number of records to merge node at */
    hbool_t          collapsed_root = FALSE;       /* Whether the root was collapsed */
    herr_t           ret_value      = SUCCEED;     /* Return value */

    FUNC_ENTER_PACKAGE

    /* Check arguments. */
    HDassert(hdr);
    HDassert(depth > 0);
    HDassert(parent_cache_info);
    HDassert(curr_node_ptr);
    HDassert(H5_addr_defined(curr_node_ptr->addr));

    /* Lock current B-tree node */
    if (NULL == (internal = H5B2__protect_internal(hdr, parent_cache_info, curr_node_ptr, depth, FALSE,
                                                   H5AC__NO_FLAGS_SET)))
        HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to protect B-tree internal node")
    internal_addr = curr_node_ptr->addr;
    HDassert(internal->nrec == curr_node_ptr->node_nrec);
    HDassert(depth == hdr->depth || internal->nrec > 1);

    /* Determine the correct number of records to merge at */
    merge_nrec = hdr->node_info[depth - 1].merge_nrec;

    /* Check for needing to collapse the root node */
    /* (The root node is the only internal node allowed to have 1 record) */
    if (internal->nrec == 1 &&
        ((internal->node_ptrs[0].node_nrec + internal->node_ptrs[1].node_nrec) <= ((merge_nrec * 2) + 1))) {
        HDassert(depth == hdr->depth);

        /* Merge children of root node */
        if (H5B2__merge2(hdr, depth, curr_node_ptr, parent_cache_info_flags_ptr, internal, &internal_flags,
                         0) < 0)
            HGOTO_ERROR(H5E_BTREE, H5E_CANTSPLIT, FAIL, "unable to merge child node")

        /* Let the cache know that the object is deleted */
        internal_flags |= H5AC__DELETED_FLAG;
        if (!hdr->swmr_write)
            internal_flags |= H5AC__FREE_FILE_SPACE_FLAG;

        /* Reset information in header's root node pointer */
        curr_node_ptr->addr      = internal->node_ptrs[0].addr;
        curr_node_ptr->node_nrec = internal->node_ptrs[0].node_nrec;

        /* Update flush dependency for child, if using SWMR */
        if (hdr->swmr_write)
            if (H5B2__update_flush_depend(hdr, depth, curr_node_ptr, internal, hdr) < 0)
                HGOTO_ERROR(H5E_BTREE, H5E_CANTUPDATE, FAIL, "unable to update child node to new parent")

        /* Indicate that the level of the B-tree decreased */
        *depth_decreased = TRUE;

        /* Set pointers for advancing to child node */
        new_cache_info           = parent_cache_info;
        new_cache_info_flags_ptr = parent_cache_info_flags_ptr;
        new_node_ptr             = curr_node_ptr;

        /* Set flag to indicate root was collapsed */
        collapsed_root = TRUE;

        /* Indicate position of next node */
        next_pos = H5B2_POS_ROOT;
    } /* end if */
    /* Merge or redistribute child node pointers, if necessary */
    else {
        hsize_t  orig_n = n;    /* Original index looked for */
        unsigned idx;           /* Location of record which matches key */
        hbool_t  found = FALSE; /* Comparison value of records */
        unsigned retries;       /* Number of times to attempt redistribution */

        /* Shadow the node if doing SWMR writes */
        if (hdr->swmr_write) {
            if (H5B2__shadow_internal(internal, curr_node_ptr) < 0)
                HGOTO_ERROR(H5E_BTREE, H5E_CANTCOPY, FAIL, "unable to shadow internal node")
            internal_addr = curr_node_ptr->addr;
        } /* end if */

        /* Locate node pointer for child */
        if (swap_loc)
            idx = 0;
        else {
            /* Search for record with correct index */
            for (idx = 0; idx < internal->nrec; idx++) {
                /* Check which child node contains indexed record */
                if (internal->node_ptrs[idx].all_nrec >= n) {
                    /* Check if record is in this node */
                    if (internal->node_ptrs[idx].all_nrec == n) {
                        /* Indicate the record was found and that the index
                         *      in child nodes is zero from now on
                         */
                        found = TRUE;
                        n     = 0;

                        /* Increment to next record */
                        idx++;
                    } /* end if */

                    /* Break out of loop early */
                    break;
                } /* end if */

                /* Decrement index we are looking for to account for the node we
                 * just advanced past.
                 */
                n -= (internal->node_ptrs[idx].all_nrec + 1);
            } /* end for */
        }     /* end else */

        /* Set the number of redistribution retries */
        /* This takes care of the case where a B-tree node needs to be
         * redistributed, but redistributing the node causes the index
         * for removal to move to another node, which also needs to be
         * redistributed.  Now, we loop trying to redistribute and then
         * eventually force a merge */
        retries = 2;

        /* Preemptively merge/redistribute a node we will enter */
        while (internal->node_ptrs[idx].node_nrec == merge_nrec) {
            /* Attempt to redistribute records among children */
            /* (NOTE: These 2-node redistributions should actually get the
             *  record to promote from the node with more records. - QAK)
             */
            /* (NOTE: This code is the same in both H5B2__remove_internal() and
             *  H5B2__remove_internal_by_idx(), fix bugs in both places! - QAK)
             */
            if (idx == 0) { /* Left-most child */
                if (retries > 0 && (internal->node_ptrs[idx + 1].node_nrec > merge_nrec)) {
                    if (H5B2__redistribute2(hdr, depth, internal, idx) < 0)
                        HGOTO_ERROR(H5E_BTREE, H5E_CANTREDISTRIBUTE, FAIL,
                                    "unable to redistribute child node records")
                } /* end if */
                else {
                    if (H5B2__merge2(hdr, depth, curr_node_ptr, parent_cache_info_flags_ptr, internal,
                                     &internal_flags, idx) < 0)
                        HGOTO_ERROR(H5E_BTREE, H5E_CANTSPLIT, FAIL, "unable to merge child node")
                }                             /* end else */
            }                                 /* end if */
            else if (idx == internal->nrec) { /* Right-most child */
                if (retries > 0 && (internal->node_ptrs[idx - 1].node_nrec > merge_nrec)) {
                    if (H5B2__redistribute2(hdr, depth, internal, (idx - 1)) < 0)
                        HGOTO_ERROR(H5E_BTREE, H5E_CANTREDISTRIBUTE, FAIL,
                                    "unable to redistribute child node records")
                } /* end if */
                else {
                    if (H5B2__merge2(hdr, depth, curr_node_ptr, parent_cache_info_flags_ptr, internal,
                                     &internal_flags, (idx - 1)) < 0)
                        HGOTO_ERROR(H5E_BTREE, H5E_CANTSPLIT, FAIL, "unable to merge child node")
                }  /* end else */
            }      /* end if */
            else { /* Middle child */
                if (retries > 0 && ((internal->node_ptrs[idx + 1].node_nrec > merge_nrec) ||
                                    (internal->node_ptrs[idx - 1].node_nrec > merge_nrec))) {
                    if (H5B2__redistribute3(hdr, depth, internal, &internal_flags, idx) < 0)
                        HGOTO_ERROR(H5E_BTREE, H5E_CANTREDISTRIBUTE, FAIL,
                                    "unable to redistribute child node records")
                } /* end if */
                else {
                    if (H5B2__merge3(hdr, depth, curr_node_ptr, parent_cache_info_flags_ptr, internal,
                                     &internal_flags, idx) < 0)
                        HGOTO_ERROR(H5E_BTREE, H5E_CANTSPLIT, FAIL, "unable to merge child node")
                } /* end else */
            }     /* end else */

            /* Locate node pointer for child (after merge/redistribute) */
            if (swap_loc)
                idx = 0;
            else {
                /* Count from the original index value again */
                n = orig_n;

                /* Reset "found" flag - the record may have shifted during the
                 *      redistribute/merge
                 */
                found = FALSE;

                /* Search for record with correct index */
                for (idx = 0; idx < internal->nrec; idx++) {
                    /* Check which child node contains indexed record */
                    if (internal->node_ptrs[idx].all_nrec >= n) {
                        /* Check if record is in this node */
                        if (internal->node_ptrs[idx].all_nrec == n) {
                            /* Indicate the record was found and that the index
                             *      in child nodes is zero from now on
                             */
                            found = TRUE;
                            n     = 0;

                            /* Increment to next record */
                            idx++;
                        } /* end if */

                        /* Break out of loop early */
                        break;
                    } /* end if */

                    /* Decrement index we are looking for to account for the node we
                     * just advanced past.
                     */
                    n -= (internal->node_ptrs[idx].all_nrec + 1);
                } /* end for */
            }     /* end else */

            /* Decrement the number of redistribution retries left */
            retries--;
        } /* end while */

        /* Handle deleting a record from an internal node */
        if (!swap_loc && found) {
            swap_loc    = H5B2_INT_NREC(internal, hdr, idx - 1);
            swap_parent = internal;
        } /* end if */

        /* Swap record to delete with record from leaf, if we are the last internal node */
        if (swap_loc && depth == 1)
            if (H5B2__swap_leaf(hdr, depth, internal, &internal_flags, idx, swap_loc) < 0)
                HGOTO_ERROR(H5E_BTREE, H5E_CANTSWAP, FAIL, "can't swap records in B-tree")

        /* Set pointers for advancing to child node */
        new_cache_info_flags_ptr = &internal_flags;
        new_cache_info           = &internal->cache_info;
        new_node_ptr             = &internal->node_ptrs[idx];

        /* Indicate position of next node */
        if (H5B2_POS_MIDDLE != curr_pos) {
            if (idx == 0) {
                if (H5B2_POS_LEFT == curr_pos || H5B2_POS_ROOT == curr_pos)
                    next_pos = H5B2_POS_LEFT;
            } /* end if */
            else if (idx == internal->nrec) {
                if (H5B2_POS_RIGHT == curr_pos || H5B2_POS_ROOT == curr_pos)
                    next_pos = H5B2_POS_RIGHT;
            } /* end if */
        }     /* end if */
    }         /* end else */

    /* Attempt to remove record from child node */
    if (depth > 1) {
        if (H5B2__remove_internal_by_idx(hdr, depth_decreased, swap_loc, swap_parent, (uint16_t)(depth - 1),
                                         new_cache_info, new_cache_info_flags_ptr, new_node_ptr, next_pos, n,
                                         op, op_data) < 0)
            HGOTO_ERROR(H5E_BTREE, H5E_CANTDELETE, FAIL, "unable to remove record from B-tree internal node")
    } /* end if */
    else {
        if (H5B2__remove_leaf_by_idx(hdr, new_node_ptr, next_pos, new_cache_info, (unsigned)n, op, op_data) <
            0)
            HGOTO_ERROR(H5E_BTREE, H5E_CANTDELETE, FAIL, "unable to remove record from B-tree leaf node")
    } /* end else */

    /* Update record count for node pointer to child node */
    if (!collapsed_root)
        new_node_ptr->all_nrec--;

    /* Mark node as dirty */
    if (!(hdr->swmr_write && collapsed_root))
        internal_flags |= H5AC__DIRTIED_FLAG;

#ifdef H5B2_DEBUG
    H5B2__assert_internal((!collapsed_root ? (curr_node_ptr->all_nrec - 1) : new_node_ptr->all_nrec), hdr,
                          internal);
#endif /* H5B2_DEBUG */

done:
    /* Release the B-tree internal node */
    if (internal && H5AC_unprotect(hdr->f, H5AC_BT2_INT, internal_addr, internal, internal_flags) < 0)
        HDONE_ERROR(H5E_BTREE, H5E_CANTUNPROTECT, FAIL, "unable to release internal B-tree node")

    FUNC_LEAVE_NOAPI(ret_value)
} /* H5B2__remove_internal_by_idx() */

/*-------------------------------------------------------------------------
 * Function:	H5B2__internal_free
 *
 * Purpose:	Destroys a B-tree internal node in memory.
 *
 * Return:	Non-negative on success/Negative on failure
 *
 * Programmer:	Quincey Koziol
 *		Feb 2 2005
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5B2__internal_free(H5B2_internal_t *internal)
{
    herr_t ret_value = SUCCEED; /* Return value */

    FUNC_ENTER_PACKAGE

    /*
     * Check arguments.
     */
    HDassert(internal);

    /* Release internal node's native key buffer */
    if (internal->int_native)
        internal->int_native = (uint8_t *)H5FL_FAC_FREE(internal->hdr->node_info[internal->depth].nat_rec_fac,
                                                        internal->int_native);

    /* Release internal node's node pointer buffer */
    if (internal->node_ptrs)
        internal->node_ptrs = (H5B2_node_ptr_t *)H5FL_FAC_FREE(
            internal->hdr->node_info[internal->depth].node_ptr_fac, internal->node_ptrs);

    /* Decrement ref. count on B-tree header */
    if (H5B2__hdr_decr(internal->hdr) < 0)
        HGOTO_ERROR(H5E_BTREE, H5E_CANTDEC, FAIL, "can't decrement ref. count on B-tree header")

    /* Sanity check */
    HDassert(NULL == internal->top_proxy);

    /* Free B-tree internal node info */
    internal = H5FL_FREE(H5B2_internal_t, internal);

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5B2__internal_free() */

#ifdef H5B2_DEBUG

/*-------------------------------------------------------------------------
 * Function:	H5B2__assert_internal
 *
 * Purpose:	Verify than an internal node is mostly sane
 *
 * Return:	Non-negative on success, negative on failure
 *
 * Programmer:	Quincey Koziol
 *		Feb 19 2005
 *
 *-------------------------------------------------------------------------
 */
H5_ATTR_PURE herr_t
H5B2__assert_internal(hsize_t parent_all_nrec, const H5B2_hdr_t H5_ATTR_NDEBUG_UNUSED *hdr,
                      const H5B2_internal_t *internal)
{
    hsize_t  tot_all_nrec; /* Total number of records at or below this node */
    uint16_t u, v;         /* Local index variables */

    /* General sanity checking on node */
    HDassert(internal->nrec <= hdr->node_info->split_nrec);

    /* Sanity checking on node pointers */
    tot_all_nrec = internal->nrec;
    for (u = 0; u < internal->nrec + 1; u++) {
        tot_all_nrec += internal->node_ptrs[u].all_nrec;

        HDassert(H5_addr_defined(internal->node_ptrs[u].addr));
        HDassert(internal->node_ptrs[u].addr > 0);
        for (v = 0; v < u; v++)
            HDassert(internal->node_ptrs[u].addr != internal->node_ptrs[v].addr);
    } /* end for */

    /* Sanity check all_nrec total in parent */
    if (parent_all_nrec > 0)
        HDassert(tot_all_nrec == parent_all_nrec);

    return (0);
} /* end H5B2__assert_internal() */

/*-------------------------------------------------------------------------
 * Function:	H5B2__assert_internal2
 *
 * Purpose:	Verify than internal nodes are mostly sane
 *
 * Return:	Non-negative on success, negative on failure
 *
 * Programmer:	Quincey Koziol
 *		Feb 19 2005
 *
 *-------------------------------------------------------------------------
 */
H5_ATTR_PURE herr_t
H5B2__assert_internal2(hsize_t parent_all_nrec, const H5B2_hdr_t H5_ATTR_NDEBUG_UNUSED *hdr,
                       const H5B2_internal_t *internal, const H5B2_internal_t *internal2)
{
    hsize_t  tot_all_nrec; /* Total number of records at or below this node */
    uint16_t u, v;         /* Local index variables */

    /* General sanity checking on node */
    HDassert(internal->nrec <= hdr->node_info->split_nrec);

    /* Sanity checking on node pointers */
    tot_all_nrec = internal->nrec;
    for (u = 0; u < internal->nrec + 1; u++) {
        tot_all_nrec += internal->node_ptrs[u].all_nrec;

        HDassert(H5_addr_defined(internal->node_ptrs[u].addr));
        HDassert(internal->node_ptrs[u].addr > 0);
        for (v = 0; v < u; v++)
            HDassert(internal->node_ptrs[u].addr != internal->node_ptrs[v].addr);
        for (v = 0; v < internal2->nrec + 1; v++)
            HDassert(internal->node_ptrs[u].addr != internal2->node_ptrs[v].addr);
    } /* end for */

    /* Sanity check all_nrec total in parent */
    if (parent_all_nrec > 0)
        HDassert(tot_all_nrec == parent_all_nrec);

    return (0);
} /* end H5B2__assert_internal2() */
#endif /* H5B2_DEBUG */