summaryrefslogtreecommitdiffstats
path: root/src/H5B.c
blob: 2772bb9be8c6cbe1f4cd91c3a1c34d9b9f4072b8 (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
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
2051
2052
2053
2054
2055
2056
2057
2058
2059
2060
2061
2062
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2078
2079
2080
2081
2082
2083
2084
2085
2086
2087
2088
2089
2090
2091
/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
 * 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.                                                        *
 * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */

/*-------------------------------------------------------------------------
 *
 * Created:		H5B.c
 *			Jul 10 1997
 *			Robb Matzke <matzke@llnl.gov>
 *
 * Purpose:		Implements balanced, sibling-linked, N-ary trees
 *			capable of storing any type of data with unique key
 *			values.
 *
 *			A B-link-tree is a balanced tree where each node has
 *			a pointer to its left and right siblings.  A
 *			B-link-tree is a rooted tree having the following
 *			properties:
 *
 *			1. Every node, x, has the following fields:
 *
 *			   a. level[x], the level in the tree at which node
 *			      x appears.  Leaf nodes are at level zero.
 *
 *			   b. n[x], the number of children pointed to by the
 *			      node.  Internal nodes point to subtrees while
 *			      leaf nodes point to arbitrary data.
 *
 *			   c. The child pointers themselves, child[x,i] such
 *			      that 0 <= i < n[x].
 *
 *			   d. n[x]+1 key values stored in increasing
 *			      order:
 *
 *				key[x,0] < key[x,1] < ... < key[x,n[x]].
 *
 *			   e. left[x] is a pointer to the node's left sibling
 *			      or the null pointer if this is the left-most
 *			      node at this level in the tree.
 *
 *			   f. right[x] is a pointer to the node's right
 *			      sibling or the null pointer if this is the
 *			      right-most node at this level in the tree.
 *
 *			3. The keys key[x,i] partition the key spaces of the
 *			   children of x:
 *
 *			      key[x,i] <= key[child[x,i],j] <= key[x,i+1]
 *
 *			   for any valid combination of i and j.
 *
 *			4. There are lower and upper bounds on the number of
 *			   child pointers a node can contain.  These bounds
 *			   can be expressed in terms of a fixed integer k>=2
 *			   called the `minimum degree' of the B-tree.
 *
 *			   a. Every node other than the root must have at least
 *			      k child pointers and k+1 keys.  If the tree is
 *			      nonempty, the root must have at least one child
 *			      pointer and two keys.
 *
 *			   b. Every node can contain at most 2k child pointers
 *			      and 2k+1 keys.  A node is `full' if it contains
 *			      exactly 2k child pointers and 2k+1 keys.
 *
 *			5. When searching for a particular value, V, and
 *			   key[V] = key[x,i] for some node x and entry i,
 *			   then:
 *
 *			   a. If i=0 the child[0] is followed.
 *
 *			   b. If i=n[x] the child[n[x]-1] is followed.
 *
 *			   c. Otherwise, the child that is followed
 *			      (either child[x,i-1] or child[x,i]) is
 *			      determined by the type of object to which the
 *			      leaf nodes of the tree point and is controlled
 *			      by the key comparison function registered for
 *			      that type of B-tree.
 *
 *
 *-------------------------------------------------------------------------
 */

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

#include "H5Bmodule.h"          /* This source code file is part of the H5B module */


/***********/
/* Headers */
/***********/
#include "H5private.h"		/* Generic Functions			*/
#include "H5Bpkg.h"		/* B-link trees				*/
#include "H5CXprivate.h"        /* API Contexts                         */
#include "H5Eprivate.h"		/* Error handling		  	*/
#include "H5Iprivate.h"		/* IDs			  		*/
#include "H5MFprivate.h"	/* File memory management		*/
#include "H5Pprivate.h"         /* Property lists                       */


/****************/
/* Local Macros */
/****************/
#define H5B_SIZEOF_HDR(F)						      \
   (H5_SIZEOF_MAGIC +		/*magic number				  */  \
    4 +				/*type, level, num entries		  */  \
    2*H5F_SIZEOF_ADDR(F))	/*left and right sibling addresses	  */

/* Default initializer for H5B_ins_ud_t */
#define H5B_INS_UD_T_NULL {NULL, HADDR_UNDEF, H5AC__NO_FLAGS_SET}

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

/* "user data" for iterating over B-tree (collects B-tree metadata size) */
typedef struct H5B_iter_ud_t {
    H5B_info_t *bt_info;        /* Information about B-tree */
    void    *udata;             /* Node type's 'udata' for loading & iterator callback */
} H5B_info_ud_t;

/* Convenience struct for the arguments needed to unprotect a b-tree after a
 * call to H5B__iterate_helper() or H5B__split() */
typedef struct H5B_ins_ud_t {
    H5B_t       *bt;            /* B-tree */
    haddr_t     addr;           /* B-tree address */
    unsigned    cache_flags;    /* Cache flags for H5AC_unprotect() */
} H5B_ins_ud_t;


/********************/
/* Local Prototypes */
/********************/
static H5B_ins_t H5B__insert_helper(H5F_t *f, H5B_ins_ud_t *bt_ud,
    const H5B_class_t *type, uint8_t *lt_key, hbool_t *lt_key_changed,
    uint8_t *md_key, void *udata, uint8_t *rt_key, hbool_t *rt_key_changed,
    H5B_ins_ud_t *split_bt_ud/*out*/);
static herr_t H5B__insert_child(H5B_t *bt, unsigned *bt_flags,
                               unsigned idx, haddr_t child,
			       H5B_ins_t anchor, const void *md_key);
static herr_t H5B__split(H5F_t *f, H5B_ins_ud_t *bt_ud, unsigned idx,
    void *udata, H5B_ins_ud_t *split_bt_ud/*out*/);
static H5B_t * H5B__copy(const H5B_t *old_bt);


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

/* Package initialization variable */
hbool_t H5_PKG_INIT_VAR = FALSE;

/* Declare a free list to manage the haddr_t sequence information */
H5FL_SEQ_DEFINE(haddr_t);

/* Declare a PQ free list to manage the native block information */
H5FL_BLK_DEFINE(native_block);

/* Declare a free list to manage the H5B_t struct */
H5FL_DEFINE(H5B_t);


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


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

/* Declare a free list to manage the H5B_shared_t struct */
H5FL_DEFINE_STATIC(H5B_shared_t);

/* Declare a free list to manage the raw page information */
H5FL_BLK_DEFINE_STATIC(page);

/* Declare a free list to manage the native key offset sequence information */
H5FL_SEQ_DEFINE_STATIC(size_t);



/*-------------------------------------------------------------------------
 * Function:	H5B_create
 *
 * Purpose:	Creates a new empty B-tree leaf node.  The UDATA pointer is
 *		passed as an argument to the sizeof_rkey() method for the
 *		B-tree.
 *
 * Return:	Success:	Non-negative, and the address of new node is
 *				returned through the ADDR_P argument.
 *
 * 		Failure:	Negative
 *
 * Programmer:	Robb Matzke
 *		matzke@llnl.gov
 *		Jun 23 1997
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5B_create(H5F_t *f, const H5B_class_t *type, void *udata, haddr_t *addr_p/*out*/)
{
    H5B_t		*bt = NULL;
    H5B_shared_t        *shared=NULL;        /* Pointer to shared B-tree info */
    herr_t		ret_value = SUCCEED;

    FUNC_ENTER_NOAPI(FAIL)

    /*
     * Check arguments.
     */
    HDassert(f);
    HDassert(type);
    HDassert(addr_p);

    /*
     * Allocate file and memory data structures.
     */
    if(NULL == (bt = H5FL_MALLOC(H5B_t)))
	HGOTO_ERROR(H5E_BTREE, H5E_CANTALLOC, FAIL, "memory allocation failed for B-tree root node")
    HDmemset(&bt->cache_info, 0, sizeof(H5AC_info_t));
    bt->level = 0;
    bt->left = HADDR_UNDEF;
    bt->right = HADDR_UNDEF;
    bt->nchildren = 0;
    if(NULL == (bt->rc_shared = (type->get_shared)(f, udata)))
	HGOTO_ERROR(H5E_BTREE, H5E_CANTGET, FAIL, "can't retrieve B-tree node buffer")
    H5UC_INC(bt->rc_shared);
    shared=(H5B_shared_t *)H5UC_GET_OBJ(bt->rc_shared);
    HDassert(shared);
    if(NULL == (bt->native = H5FL_BLK_MALLOC(native_block, shared->sizeof_keys)) ||
            NULL == (bt->child = H5FL_SEQ_MALLOC(haddr_t, (size_t)shared->two_k)))
	HGOTO_ERROR(H5E_BTREE, H5E_CANTALLOC, FAIL, "memory allocation failed for B-tree root node")
    if(HADDR_UNDEF == (*addr_p = H5MF_alloc(f, H5FD_MEM_BTREE, (hsize_t)shared->sizeof_rnode)))
        HGOTO_ERROR(H5E_BTREE, H5E_CANTALLOC, FAIL, "file allocation failed for B-tree root node")

    /*
     * Cache the new B-tree node.
     */
    if(H5AC_insert_entry(f, H5AC_BT, *addr_p, bt, H5AC__NO_FLAGS_SET) < 0)
	HGOTO_ERROR(H5E_BTREE, H5E_CANTINIT, FAIL, "can't add B-tree root node to cache")
#ifdef H5B_DEBUG
    H5B__assert(f, *addr_p, shared->type, udata);
#endif

done:
    if(ret_value < 0) {
        if(shared && shared->sizeof_rnode>0) {
            H5_CHECK_OVERFLOW(shared->sizeof_rnode,size_t,hsize_t);
            (void)H5MF_xfree(f, H5FD_MEM_BTREE, *addr_p, (hsize_t)shared->sizeof_rnode);
        } /* end if */
	if(bt)
            /* Destroy B-tree node */
            if(H5B__node_dest(bt) < 0)
                HDONE_ERROR(H5E_BTREE, H5E_CANTFREE, FAIL, "unable to destroy B-tree node")
    } /* end if */

    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5B_create() */        /*lint !e818 Can't make udata a pointer to const */


/*-------------------------------------------------------------------------
 * Function:	H5B_find
 *
 * Purpose:	Locate the specified information in a B-tree 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.
 *
 * Note:	This function does not follow the left/right sibling
 *		pointers since it assumes that all nodes can be reached
 *		from the parent node.
 *
 * Return:	Non-negative (TRUE/FALSE) on success (if found, values returned
 *              through the UDATA argument). Negative on failure (if not found,
 *              UDATA is undefined).
 *
 * Programmer:	Robb Matzke
 *		matzke@llnl.gov
 *		Jun 23 1997
 *
 *-------------------------------------------------------------------------
 */
htri_t
H5B_find(H5F_t *f, const H5B_class_t *type, haddr_t addr, void *udata)
{
    H5B_t	*bt = NULL;
    H5UC_t	*rc_shared;             /* Ref-counted shared info */
    H5B_shared_t *shared;               /* Pointer to shared B-tree info */
    H5B_cache_ud_t cache_udata;         /* User-data for metadata cache callback */
    unsigned    idx = 0, lt = 0, rt;    /* Final, left & right key indices */
    int	        cmp = 1;                /* Key comparison value */
    htri_t	ret_value = FAIL;       /* Return value */

    FUNC_ENTER_NOAPI(FAIL)

    /*
     * Check arguments.
     */
    HDassert(f);
    HDassert(type);
    HDassert(type->decode);
    HDassert(type->cmp3);
    HDassert(type->found);
    HDassert(H5F_addr_defined(addr));

    /* Get shared info for B-tree */
    if(NULL == (rc_shared = (type->get_shared)(f, udata)))
        HGOTO_ERROR(H5E_BTREE, H5E_CANTGET, FAIL, "can't retrieve B-tree's shared ref. count object")
    shared = (H5B_shared_t *)H5UC_GET_OBJ(rc_shared);
    HDassert(shared);

    /*
     * Perform a binary search to locate the child which contains
     * the thing for which we're searching.
     */
    cache_udata.f = f;
    cache_udata.type = type;
    cache_udata.rc_shared = rc_shared;
    if(NULL == (bt = (H5B_t *)H5AC_protect(f, H5AC_BT, addr, &cache_udata, H5AC__READ_ONLY_FLAG)))
        HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to load B-tree node")

    rt = bt->nchildren;
    while(lt < rt && cmp) {
	idx = (lt + rt) / 2;
	/* compare */
	if((cmp = (type->cmp3)(H5B_NKEY(bt, shared, idx), udata, H5B_NKEY(bt, shared, (idx + 1)))) < 0)
	    rt = idx;
	else
	    lt = idx + 1;
    } /* end while */
    /* Check if not found */
    if(cmp)
	HGOTO_DONE(FALSE)

    /*
     * Follow the link to the subtree or to the data node.
     */
    HDassert(idx < bt->nchildren);

    if(bt->level > 0) {
	if((ret_value = H5B_find(f, type, bt->child[idx], udata)) < 0)
	    HGOTO_ERROR(H5E_BTREE, H5E_NOTFOUND, FAIL, "can't lookup key in subtree")
    } /* end if */
    else {
	if((ret_value = (type->found)(f, bt->child[idx], H5B_NKEY(bt, shared, idx), udata)) < 0)
            HGOTO_ERROR(H5E_BTREE, H5E_NOTFOUND, FAIL, "can't lookup key in leaf node")
    } /* end else */

done:
    if(bt && H5AC_unprotect(f, H5AC_BT, addr, bt, H5AC__NO_FLAGS_SET) < 0)
	HDONE_ERROR(H5E_BTREE, H5E_CANTUNPROTECT, FAIL, "unable to release node")

    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5B_find() */


/*-------------------------------------------------------------------------
 * Function:	H5B__split
 *
 * Purpose:	Split a single node into two nodes.  The old node will
 *		contain the left children and the new node will contain the
 *		right children.
 *
 *		The UDATA pointer is passed to the sizeof_rkey() method but is
 *		otherwise unused.
 *
 *		The BT_UD argument is a pointer to a protected B-tree
 *		node.
 *
 * Return:	Non-negative on success (The address of the new node is
 *              returned through the NEW_ADDR argument). Negative on failure.
 *
 * Programmer:	Robb Matzke
 *		matzke@llnl.gov
 *		Jul  3 1997
 *
 *-------------------------------------------------------------------------
 */
static herr_t
H5B__split(H5F_t *f, H5B_ins_ud_t *bt_ud, unsigned idx,
    void *udata, H5B_ins_ud_t *split_bt_ud/*out*/)
{
    H5B_shared_t  *shared;              /* Pointer to shared B-tree info */
    H5B_cache_ud_t cache_udata;         /* User-data for metadata cache callback */
    unsigned	nleft, nright;          /* Number of keys in left & right halves */
    double      split_ratios[3];        /* B-tree split ratios */
    herr_t	ret_value = SUCCEED;    /* Return value */

    FUNC_ENTER_STATIC

    /*
     * Check arguments.
     */
    HDassert(f);
    HDassert(bt_ud);
    HDassert(bt_ud->bt);
    HDassert(H5F_addr_defined(bt_ud->addr));
    HDassert(split_bt_ud);
    HDassert(!split_bt_ud->bt);

    /*
     * Initialize variables.
     */
    shared = (H5B_shared_t *)H5UC_GET_OBJ(bt_ud->bt->rc_shared);
    HDassert(shared);
    HDassert(bt_ud->bt->nchildren == shared->two_k);

    /* Get B-tree split ratios */
    if(H5CX_get_btree_split_ratios(split_ratios) < 0)
        HGOTO_ERROR(H5E_BTREE, H5E_CANTGET, FAIL, "can't retrieve B-tree split ratios")

#ifdef H5B_DEBUG
    if(H5DEBUG(B)) {
	const char *side;

	if(!H5F_addr_defined(bt_ud->bt->left) && !H5F_addr_defined(bt_ud->bt->right))
	    side = "ONLY";
	else if(!H5F_addr_defined(bt_ud->bt->right))
	    side = "RIGHT";
	else if(!H5F_addr_defined(bt_ud->bt->left))
	    side = "LEFT";
	else
	    side = "MIDDLE";
        HDfprintf(H5DEBUG(B), "H5B__split: %3u {%5.3f,%5.3f,%5.3f} %6s",
            shared->two_k, split_ratios[0], split_ratios[1], split_ratios[2], side);
    }
#endif

    /*
     * Decide how to split the children of the old node among the old node
     * and the new node.
     */
    if(!H5F_addr_defined(bt_ud->bt->right))
	nleft = (unsigned)((double)shared->two_k * split_ratios[2]);	/*right*/
    else if(!H5F_addr_defined(bt_ud->bt->left))
	nleft = (unsigned)((double)shared->two_k * split_ratios[0]);	/*left*/
    else
	nleft = (unsigned)((double)shared->two_k * split_ratios[1]);	/*middle*/

    /*
     * Keep the new child in the same node as the child that split.  This can
     * result in nodes that have an unused child when data is written
     * sequentially, but it simplifies stuff below.
     */
    if(idx < nleft && nleft == shared->two_k)
	--nleft;
    else if(idx >= nleft && 0 == nleft)
	nleft++;
    nright = shared->two_k - nleft;
#ifdef H5B_DEBUG
    if(H5DEBUG(B))
        HDfprintf(H5DEBUG(B), " split %3d/%-3d\n", nleft, nright);
#endif

    /*
     * Create the new B-tree node.
     */
    if(H5B_create(f, shared->type, udata, &split_bt_ud->addr/*out*/) < 0)
        HGOTO_ERROR(H5E_BTREE, H5E_CANTINIT, FAIL, "unable to create B-tree")
    cache_udata.f = f;
    cache_udata.type = shared->type;
    cache_udata.rc_shared = bt_ud->bt->rc_shared;
    if(NULL == (split_bt_ud->bt = (H5B_t *)H5AC_protect(f, H5AC_BT, split_bt_ud->addr, &cache_udata, H5AC__NO_FLAGS_SET)))
        HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to protect B-tree")
    split_bt_ud->bt->level = bt_ud->bt->level;

    /*
     * Copy data from the old node to the new node.
     */

    split_bt_ud->cache_flags = H5AC__DIRTIED_FLAG;
    HDmemcpy(split_bt_ud->bt->native,
	     bt_ud->bt->native + nleft * shared->type->sizeof_nkey,
	     (nright + 1) * shared->type->sizeof_nkey);
    HDmemcpy(split_bt_ud->bt->child,
            &bt_ud->bt->child[nleft],
            nright * sizeof(haddr_t));

    split_bt_ud->bt->nchildren = nright;

    /*
     * Truncate the old node.
     */
    bt_ud->cache_flags |= H5AC__DIRTIED_FLAG;
    bt_ud->bt->nchildren = nleft;

    /*
     * Update other sibling pointers.
     */
    split_bt_ud->bt->left = bt_ud->addr;
    split_bt_ud->bt->right = bt_ud->bt->right;

    if(H5F_addr_defined(bt_ud->bt->right)) {
        H5B_t   *tmp_bt;

        if(NULL == (tmp_bt = (H5B_t *)H5AC_protect(f, H5AC_BT, bt_ud->bt->right, &cache_udata, H5AC__NO_FLAGS_SET)))
            HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to load right sibling")

        tmp_bt->left = split_bt_ud->addr;

        if(H5AC_unprotect(f, H5AC_BT, bt_ud->bt->right, tmp_bt, H5AC__DIRTIED_FLAG) < 0)
            HGOTO_ERROR(H5E_BTREE, H5E_CANTUNPROTECT, FAIL, "unable to release B-tree node")
    } /* end if */

    bt_ud->bt->right = split_bt_ud->addr;
    HDassert(bt_ud->cache_flags & H5AC__DIRTIED_FLAG);

done:
    if(ret_value < 0) {
        if(split_bt_ud->bt && H5AC_unprotect(f, H5AC_BT, split_bt_ud->addr, split_bt_ud->bt, split_bt_ud->cache_flags) < 0)
            HDONE_ERROR(H5E_BTREE, H5E_CANTUNPROTECT, FAIL, "unable to release B-tree node")
        split_bt_ud->bt = NULL;
        split_bt_ud->addr = HADDR_UNDEF;
        split_bt_ud->cache_flags = H5AC__NO_FLAGS_SET;
    } /* end if */

    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5B__split() */


/*-------------------------------------------------------------------------
 * Function:	H5B_insert
 *
 * Purpose:	Adds a new item to the B-tree.
 *
 * Return:	Non-negative on success/Negative on failure
 *
 * Programmer:	Robb Matzke
 *		matzke@llnl.gov
 *		Jun 23 1997
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5B_insert(H5F_t *f, const H5B_class_t *type, haddr_t addr, void *udata)
{
    /*
     * These are defined this way to satisfy alignment constraints.
     */
    uint64_t	_lt_key[128], _md_key[128], _rt_key[128];
    uint8_t	*lt_key=(uint8_t*)_lt_key;
    uint8_t	*md_key=(uint8_t*)_md_key;
    uint8_t	*rt_key=(uint8_t*)_rt_key;

    hbool_t	lt_key_changed = FALSE, rt_key_changed = FALSE;
    haddr_t     old_root_addr = HADDR_UNDEF;
    unsigned	level;
    H5B_ins_ud_t bt_ud = H5B_INS_UD_T_NULL; /* (Old) root node */
    H5B_ins_ud_t split_bt_ud = H5B_INS_UD_T_NULL; /* Split B-tree node */
    H5B_t       *new_root_bt = NULL;    /* New root node */
    H5UC_t	*rc_shared;             /* Ref-counted shared info */
    H5B_shared_t        *shared;        /* Pointer to shared B-tree info */
    H5B_cache_ud_t cache_udata;         /* User-data for metadata cache callback */
    H5B_ins_t	my_ins = H5B_INS_ERROR;
    herr_t	ret_value = SUCCEED;

    FUNC_ENTER_NOAPI(FAIL)

    /* Check arguments. */
    HDassert(f);
    HDassert(type);
    HDassert(type->sizeof_nkey <= sizeof _lt_key);
    HDassert(H5F_addr_defined(addr));

    /* Get shared info for B-tree */
    if(NULL == (rc_shared = (type->get_shared)(f, udata)))
        HGOTO_ERROR(H5E_BTREE, H5E_CANTGET, FAIL, "can't retrieve B-tree's shared ref. count object")
    shared = (H5B_shared_t *)H5UC_GET_OBJ(rc_shared);
    HDassert(shared);

    /* Protect the root node */
    cache_udata.f = f;
    cache_udata.type = type;
    cache_udata.rc_shared = rc_shared;
    bt_ud.addr = addr;
    if(NULL == (bt_ud.bt = (H5B_t *)H5AC_protect(f, H5AC_BT, addr, &cache_udata, H5AC__NO_FLAGS_SET)))
        HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to locate root of B-tree")

    /* Insert the object */
    if((int)(my_ins = H5B__insert_helper(f, &bt_ud, type, lt_key,
            &lt_key_changed, md_key, udata, rt_key, &rt_key_changed,
            &split_bt_ud/*out*/)) < 0)
	HGOTO_ERROR(H5E_BTREE, H5E_CANTINIT, FAIL, "unable to insert key")

    /* Check if the root node split */
    if(H5B_INS_NOOP == my_ins) {
        /* The root node did not split - just return */
        HDassert(!split_bt_ud.bt);
        HGOTO_DONE(SUCCEED)
    } /* end if */
    HDassert(H5B_INS_RIGHT == my_ins);
    HDassert(split_bt_ud.bt);
    HDassert(H5F_addr_defined(split_bt_ud.addr));

    /* Get level of old root */
    level = bt_ud.bt->level;

    /* update left and right keys */
    if(!lt_key_changed)
	HDmemcpy(lt_key, H5B_NKEY(bt_ud.bt,shared,0), type->sizeof_nkey);
    if(!rt_key_changed)
	HDmemcpy(rt_key, H5B_NKEY(split_bt_ud.bt,shared,split_bt_ud.bt->nchildren), type->sizeof_nkey);

    /*
     * Copy the old root node to some other file location and make the new root
     * at the old root's previous address.  This prevents the B-tree from
     * "moving".
     */
    H5_CHECK_OVERFLOW(shared->sizeof_rnode,size_t,hsize_t);
    if(HADDR_UNDEF == (old_root_addr = H5MF_alloc(f, H5FD_MEM_BTREE, (hsize_t)shared->sizeof_rnode)))
	HGOTO_ERROR(H5E_BTREE, H5E_CANTALLOC, FAIL, "unable to allocate file space to move root")

    /*
     * Move the node to the new location
     */

    /* Make a copy of the old root information */
    if(NULL == (new_root_bt = H5B__copy(bt_ud.bt)))
        HGOTO_ERROR(H5E_BTREE, H5E_CANTCOPY, FAIL, "unable to copy old root")

    /* Unprotect the old root so we can move it.  Also force it to be marked
     * dirty so it is written to the new location. */
    if(H5AC_unprotect(f, H5AC_BT, bt_ud.addr, bt_ud.bt, H5AC__DIRTIED_FLAG) < 0)
	HGOTO_ERROR(H5E_BTREE, H5E_CANTUNPROTECT, FAIL, "unable to release old root")
    bt_ud.bt = NULL;  /* Make certain future references will be caught */

    /* Move the location of the old root on the disk */
    if(H5AC_move_entry(f, H5AC_BT, bt_ud.addr, old_root_addr) < 0)
	HGOTO_ERROR(H5E_BTREE, H5E_CANTSPLIT, FAIL, "unable to move B-tree root node")
    bt_ud.addr = old_root_addr;

    /* Update the split b-tree's left pointer to point to the new location */
    split_bt_ud.bt->left = bt_ud.addr;
    split_bt_ud.cache_flags |= H5AC__DIRTIED_FLAG;

    /* clear the old root info at the old address (we already copied it) */
    new_root_bt->left = HADDR_UNDEF;
    new_root_bt->right = HADDR_UNDEF;

    /* Set the new information for the copy */
    new_root_bt->level = level + 1;
    new_root_bt->nchildren = 2;

    new_root_bt->child[0] = bt_ud.addr;
    HDmemcpy(H5B_NKEY(new_root_bt, shared, 0), lt_key, shared->type->sizeof_nkey);

    new_root_bt->child[1] = split_bt_ud.addr;
    HDmemcpy(H5B_NKEY(new_root_bt, shared, 1), md_key, shared->type->sizeof_nkey);
    HDmemcpy(H5B_NKEY(new_root_bt, shared, 2), rt_key, shared->type->sizeof_nkey);

    /* Insert the modified copy of the old root into the file again */
    if(H5AC_insert_entry(f, H5AC_BT, addr, new_root_bt, H5AC__NO_FLAGS_SET) < 0)
        HGOTO_ERROR(H5E_BTREE, H5E_CANTFLUSH, FAIL, "unable to add old B-tree root node to cache")

done:
    if(ret_value < 0)
        if(new_root_bt && H5B__node_dest(new_root_bt) < 0)
            HDONE_ERROR(H5E_BTREE, H5E_CANTRELEASE, FAIL, "unable to free B-tree root node");

    if(bt_ud.bt)
        if(H5AC_unprotect(f, H5AC_BT, bt_ud.addr, bt_ud.bt, bt_ud.cache_flags) < 0)
            HDONE_ERROR(H5E_BTREE, H5E_CANTUNPROTECT, FAIL, "unable to unprotect old root")

    if(split_bt_ud.bt)
        if(H5AC_unprotect(f, H5AC_BT, split_bt_ud.addr, split_bt_ud.bt, split_bt_ud.cache_flags) < 0)
            HDONE_ERROR(H5E_BTREE, H5E_CANTUNPROTECT, FAIL, "unable to unprotect new child")

#ifdef H5B_DEBUG
    if(ret_value >= 0)
        H5B__assert(f, addr, type, udata);
#endif

    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5B_insert() */


/*-------------------------------------------------------------------------
 * Function:	H5B__insert_child
 *
 * Purpose:	Insert a child to the left or right of child[IDX] depending
 *		on whether ANCHOR is H5B_INS_LEFT or H5B_INS_RIGHT. The BT
 *		argument is a pointer to a protected B-tree node.
 *
 * Return:	Non-negative on success/Negative on failure
 *
 * Programmer:	Robb Matzke
 *		matzke@llnl.gov
 *		Jul  8 1997
 *
 *-------------------------------------------------------------------------
 */
static herr_t
H5B__insert_child(H5B_t *bt, unsigned *bt_flags, unsigned idx,
    haddr_t child, H5B_ins_t anchor, const void *md_key)
{
    H5B_shared_t        *shared;        /* Pointer to shared B-tree info */
    uint8_t             *base;          /* Base offset for move */

    FUNC_ENTER_STATIC_NOERR

    HDassert(bt);
    HDassert(bt_flags);
    HDassert(H5F_addr_defined(child));
    shared = (H5B_shared_t *)H5UC_GET_OBJ(bt->rc_shared);
    HDassert(shared);
    HDassert(bt->nchildren < shared->two_k);

    /* Check for inserting right-most key into node (common when just appending
     * records to an unlimited dimension chunked dataset)
     */
    base = H5B_NKEY(bt, shared, (idx + 1));
    if((idx + 1) == bt->nchildren) {
        /* Make room for the new key */
        HDmemcpy(base + shared->type->sizeof_nkey, base,
                  shared->type->sizeof_nkey);   /* No overlap possible - memcpy() OK */
        HDmemcpy(base, md_key, shared->type->sizeof_nkey);

        /* The MD_KEY is the left key of the new node */
        if(H5B_INS_RIGHT == anchor)
            idx++;  /* Don't have to memmove() child addresses down, just add new child */
        else
            /* Make room for the new child address */
            bt->child[idx + 1] = bt->child[idx];
    } /* end if */
    else {
        /* Make room for the new key */
        HDmemmove(base + shared->type->sizeof_nkey, base,
                  (bt->nchildren - idx) * shared->type->sizeof_nkey);
        HDmemcpy(base, md_key, shared->type->sizeof_nkey);

        /* The MD_KEY is the left key of the new node */
        if(H5B_INS_RIGHT == anchor)
            idx++;

        /* Make room for the new child address */
        HDmemmove(bt->child + idx + 1, bt->child + idx,
                  (bt->nchildren - idx) * sizeof(haddr_t));
    } /* end if */

    bt->child[idx] = child;
    bt->nchildren += 1;

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

    FUNC_LEAVE_NOAPI(SUCCEED)
} /* end H5B_insert_child() */


/*-------------------------------------------------------------------------
 * Function:	H5B__insert_helper
 *
 * Purpose:	Inserts the item UDATA into the tree rooted at ADDR and having
 *		the specified type.
 *
 *		On return, if LT_KEY_CHANGED is non-zero, then LT_KEY is
 *		the new native left key.  Similarly for RT_KEY_CHANGED
 *		and RT_KEY.
 *
 *		If the node splits, then MD_KEY contains the key that
 *		was split between the two nodes (that is, the key that
 *		appears as the max key in the left node and the min key
 *		in the right node).
 *
 * Return:	Success:	A B-tree operation.  The address of the new
 *				node, if the node splits, is returned through
 *				the NEW_NODE_P argument. The new node is always
 *				to the right of the previous node.  This
 *				function is called recursively and the return
 *				value influences the behavior of the caller.
 *				See also, declaration of H5B_ins_t.
 *
 *		Failure:	H5B_INS_ERROR
 *
 * Programmer:	Robb Matzke
 *		matzke@llnl.gov
 *		Jul  9 1997
 *
 *-------------------------------------------------------------------------
 */
static H5B_ins_t
H5B__insert_helper(H5F_t *f, H5B_ins_ud_t *bt_ud, const H5B_class_t *type,
    uint8_t *lt_key, hbool_t *lt_key_changed, uint8_t *md_key, void *udata,
    uint8_t *rt_key, hbool_t *rt_key_changed, H5B_ins_ud_t *split_bt_ud/*out*/)
{
    H5B_t       *bt;                    /* Convenience pointer to B-tree */
    H5UC_t	*rc_shared;             /* Ref-counted shared info */
    H5B_shared_t *shared;               /* Pointer to shared B-tree info */
    H5B_cache_ud_t cache_udata;         /* User-data for metadata cache callback */
    unsigned	lt = 0, idx = 0, rt;    /* Left, final & right index values */
    int         cmp = -1;               /* Key comparison value */
    H5B_ins_ud_t child_bt_ud = H5B_INS_UD_T_NULL; /* Child B-tree */
    H5B_ins_ud_t new_child_bt_ud = H5B_INS_UD_T_NULL; /* Newly split child B-tree */
    H5B_ins_t	my_ins = H5B_INS_ERROR;
    H5B_ins_t	ret_value = H5B_INS_ERROR;      /* Return value */

    FUNC_ENTER_STATIC

    /*
     * Check arguments
     */
    HDassert(f);
    HDassert(bt_ud);
    HDassert(bt_ud->bt);
    HDassert(H5F_addr_defined(bt_ud->addr));
    HDassert(type);
    HDassert(type->decode);
    HDassert(type->cmp3);
    HDassert(type->new_node);
    HDassert(lt_key);
    HDassert(lt_key_changed);
    HDassert(rt_key);
    HDassert(rt_key_changed);
    HDassert(split_bt_ud);
    HDassert(!split_bt_ud->bt);
    HDassert(!H5F_addr_defined(split_bt_ud->addr));
    HDassert(split_bt_ud->cache_flags == H5AC__NO_FLAGS_SET);

    bt = bt_ud->bt;

    *lt_key_changed = FALSE;
    *rt_key_changed = FALSE;

    /* Get shared info for B-tree */
    if(NULL == (rc_shared = (type->get_shared)(f, udata)))
	HGOTO_ERROR(H5E_BTREE, H5E_CANTGET, H5B_INS_ERROR, "can't retrieve B-tree's shared ref. count object")
    shared = (H5B_shared_t *)H5UC_GET_OBJ(rc_shared);
    HDassert(shared);

    /*
     * Use a binary search to find the child that will receive the new
     * data.  When the search completes IDX points to the child that
     * should get the new data.
     */
    rt = bt->nchildren;

    while(lt < rt && cmp) {
	idx = (lt + rt) / 2;
	if((cmp = (type->cmp3)(H5B_NKEY(bt, shared, idx), udata, H5B_NKEY(bt, shared, idx + 1))) < 0)
	    rt = idx;
	else
	    lt = idx + 1;
    } /* end while */

    /* Set up user data for cache callbacks */
    cache_udata.f = f;
    cache_udata.type = type;
    cache_udata.rc_shared = rc_shared;

    if(0 == bt->nchildren) {
	/*
	 * The value being inserted will be the only value in this tree. We
	 * must necessarily be at level zero.
	 */
	HDassert(0 == bt->level);
	if((type->new_node)(f, H5B_INS_FIRST, H5B_NKEY(bt, shared, 0), udata,
			     H5B_NKEY(bt, shared, 1), bt->child + 0/*out*/) < 0)
	    HGOTO_ERROR(H5E_BTREE, H5E_CANTINIT, H5B_INS_ERROR, "unable to create leaf node")
	bt->nchildren = 1;
        bt_ud->cache_flags |= H5AC__DIRTIED_FLAG;
	idx = 0;

	if(type->follow_min) {
	    if((int)(my_ins = (type->insert)(f, bt->child[idx], H5B_NKEY(bt, shared, idx),
                     lt_key_changed, md_key, udata, H5B_NKEY(bt, shared, idx + 1),
                     rt_key_changed, &new_child_bt_ud.addr/*out*/)) < 0)
		HGOTO_ERROR(H5E_BTREE, H5E_CANTINSERT, H5B_INS_ERROR, "unable to insert first leaf node")
	} /* end if */
        else
	    my_ins = H5B_INS_NOOP;
    } else if(cmp < 0 && idx == 0) {
        if(bt->level > 0) {
            /*
             * The value being inserted is less than any value in this tree.
             * Follow the minimum branch out of this node to a subtree.
             */
            child_bt_ud.addr = bt->child[idx];
            if(NULL == (child_bt_ud.bt = (H5B_t *)H5AC_protect(f, H5AC_BT, child_bt_ud.addr, &cache_udata, H5AC__NO_FLAGS_SET)))
                HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, H5B_INS_ERROR, "unable to load node")

            if((int)(my_ins = H5B__insert_helper(f, &child_bt_ud, type,
                    H5B_NKEY(bt,shared,idx), lt_key_changed, md_key,
                    udata, H5B_NKEY(bt, shared, idx + 1), rt_key_changed,
                    &new_child_bt_ud/*out*/)) < 0)
                HGOTO_ERROR(H5E_BTREE, H5E_CANTINSERT, H5B_INS_ERROR, "can't insert minimum subtree")
        } else if(type->follow_min) {
            /*
             * The value being inserted is less than any leaf node out of this
             * current node.  Follow the minimum branch to a leaf node and let
             * the subclass handle the problem.
             */
            if((int)(my_ins = (type->insert)(f, bt->child[idx], H5B_NKEY(bt, shared, idx),
                    lt_key_changed, md_key, udata, H5B_NKEY(bt, shared, idx + 1),
                    rt_key_changed, &new_child_bt_ud.addr/*out*/)) < 0)
                HGOTO_ERROR(H5E_BTREE, H5E_CANTINSERT, H5B_INS_ERROR, "can't insert minimum leaf node")
        } else {
            /*
             * The value being inserted is less than any leaf node out of the
             * current node. Create a new minimum leaf node out of this B-tree
             * node. This node is not empty (handled above).
             */
            my_ins = H5B_INS_LEFT;
            HDmemcpy(md_key, H5B_NKEY(bt,shared,idx), type->sizeof_nkey);
            if((type->new_node)(f, H5B_INS_LEFT, H5B_NKEY(bt, shared, idx), udata,
                    md_key, &new_child_bt_ud.addr/*out*/) < 0)
                HGOTO_ERROR(H5E_BTREE, H5E_CANTINSERT, H5B_INS_ERROR, "can't insert minimum leaf node")
            *lt_key_changed = TRUE;
        } /* end else */

#ifdef H5_STRICT_FORMAT_CHECKS
        /* Since we are to the left of the leftmost key there must not be a left
         * sibling */
        if(H5F_addr_defined(bt->left))
            HGOTO_ERROR(H5E_BTREE, H5E_CANTINSERT, H5B_INS_ERROR, "internal error: likely corrupt key values")
#endif /* H5_STRICT_FORMAT_CHECKS */
    } else if(cmp > 0 && idx + 1 >= bt->nchildren) {
        if (bt->level > 0) {
            /*
            * The value being inserted is larger than any value in this tree.
            * Follow the maximum branch out of this node to a subtree.
            */
            idx = bt->nchildren - 1;
            child_bt_ud.addr = bt->child[idx];
            if(NULL == (child_bt_ud.bt = (H5B_t *)H5AC_protect(f, H5AC_BT, child_bt_ud.addr, &cache_udata, H5AC__NO_FLAGS_SET)))
                HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, H5B_INS_ERROR, "unable to load node")

            if((int)(my_ins = H5B__insert_helper(f, &child_bt_ud, type,
                    H5B_NKEY(bt, shared, idx), lt_key_changed, md_key, udata,
                    H5B_NKEY(bt, shared, idx + 1), rt_key_changed,
                    &new_child_bt_ud/*out*/)) < 0)
                HGOTO_ERROR(H5E_BTREE, H5E_CANTINSERT, H5B_INS_ERROR, "can't insert maximum subtree")
        } else if(type->follow_max) {
            /*
             * The value being inserted is larger than any leaf node out of the
             * current node.  Follow the maximum branch to a leaf node and let
             * the subclass handle the problem.
             */
            idx = bt->nchildren - 1;
            if((int)(my_ins = (type->insert)(f, bt->child[idx], H5B_NKEY(bt, shared, idx),
                    lt_key_changed, md_key, udata, H5B_NKEY(bt, shared, idx + 1),
                    rt_key_changed, &new_child_bt_ud.addr/*out*/)) < 0)
                HGOTO_ERROR(H5E_BTREE, H5E_CANTINSERT, H5B_INS_ERROR, "can't insert maximum leaf node")
        } else {
            /*
             * The value being inserted is larger than any leaf node out of the
             * current node.  Create a new maximum leaf node out of this B-tree
             * node.
             */
            idx = bt->nchildren - 1;
            my_ins = H5B_INS_RIGHT;
            HDmemcpy(md_key, H5B_NKEY(bt, shared, idx + 1), type->sizeof_nkey);
            if((type->new_node)(f, H5B_INS_RIGHT, md_key, udata,
                    H5B_NKEY(bt, shared, idx + 1), &new_child_bt_ud.addr/*out*/) < 0)
                HGOTO_ERROR(H5E_BTREE, H5E_CANTINSERT, H5B_INS_ERROR, "can't insert maximum leaf node")
            *rt_key_changed = TRUE;
        } /* end else */

#ifdef H5_STRICT_FORMAT_CHECKS
        /* Since we are to the right of the rightmost key there must not be a
         * right sibling */
        if(H5F_addr_defined(bt->right))
            HGOTO_ERROR(H5E_BTREE, H5E_CANTINSERT, H5B_INS_ERROR, "internal error: likely corrupt key values")
#endif /* H5_STRICT_FORMAT_CHECKS */
    } else if(cmp) {
	/*
	 * We couldn't figure out which branch to follow out of this node. THIS
	 * IS A MAJOR PROBLEM THAT NEEDS TO BE FIXED --rpm.
	 */
	HDassert("INTERNAL HDF5 ERROR (contact rpm)" && 0);
#ifdef NDEBUG
	HDabort();
#endif /* NDEBUG */
    } else if(bt->level > 0) {
	/*
	 * Follow a branch out of this node to another subtree.
	 */
	HDassert(idx < bt->nchildren);
	child_bt_ud.addr = bt->child[idx];
        if(NULL == (child_bt_ud.bt = (H5B_t *)H5AC_protect(f, H5AC_BT, child_bt_ud.addr, &cache_udata, H5AC__NO_FLAGS_SET)))
            HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, H5B_INS_ERROR, "unable to load node")

	if((int)(my_ins = H5B__insert_helper(f, &child_bt_ud, type,
                H5B_NKEY(bt, shared, idx), lt_key_changed, md_key, udata,
                H5B_NKEY(bt, shared, idx + 1), rt_key_changed, &new_child_bt_ud/*out*/)) < 0)
	    HGOTO_ERROR(H5E_BTREE, H5E_CANTINSERT, H5B_INS_ERROR, "can't insert subtree")
    } else {
	/*
	 * Follow a branch out of this node to a leaf node of some other type.
	 */
	HDassert(idx < bt->nchildren);
	if((int)(my_ins = (type->insert)(f, bt->child[idx], H5B_NKEY(bt, shared, idx),
                  lt_key_changed, md_key, udata, H5B_NKEY(bt, shared, idx + 1),
                  rt_key_changed, &new_child_bt_ud.addr/*out*/)) < 0)
	    HGOTO_ERROR(H5E_BTREE, H5E_CANTINSERT, H5B_INS_ERROR, "can't insert leaf node")
    }
    HDassert((int)my_ins >= 0);

    /*
     * Update the left and right keys of the current node.
     */
    if(*lt_key_changed) {
        bt_ud->cache_flags |= H5AC__DIRTIED_FLAG;
        if(idx > 0) {
            HDassert(type->critical_key == H5B_LEFT);
            HDassert(!(H5B_INS_LEFT == my_ins || H5B_INS_RIGHT == my_ins));
            *lt_key_changed = FALSE;
        } /* end if */
        else
            HDmemcpy(lt_key, H5B_NKEY(bt, shared, idx), type->sizeof_nkey);
    } /* end if */
    if(*rt_key_changed) {
        bt_ud->cache_flags |= H5AC__DIRTIED_FLAG;
        if(idx + 1 < bt->nchildren) {
            HDassert(type->critical_key == H5B_RIGHT);
            HDassert(!(H5B_INS_LEFT == my_ins || H5B_INS_RIGHT == my_ins));
            *rt_key_changed = FALSE;
        } /* end if */
        else
            HDmemcpy(rt_key, H5B_NKEY(bt, shared, idx + 1), type->sizeof_nkey);
    } /* end if */

    /*
     * Handle changes/additions to children
     */
    HDassert(!(bt->level == 0) != !(child_bt_ud.bt));
    if(H5B_INS_CHANGE == my_ins) {
	/*
	 * The insertion simply changed the address for the child.
	 */
	HDassert(!child_bt_ud.bt);
	HDassert(bt->level == 0);
	bt->child[idx] = new_child_bt_ud.addr;
        bt_ud->cache_flags |= H5AC__DIRTIED_FLAG;
    } else if(H5B_INS_LEFT == my_ins || H5B_INS_RIGHT == my_ins) {
        unsigned *tmp_bt_flags_ptr = NULL;
        H5B_t	*tmp_bt;

	/*
	 * If this node is full then split it before inserting the new child.
	 */
	if(bt->nchildren == shared->two_k) {
	    if(H5B__split(f, bt_ud, idx, udata, split_bt_ud/*out*/) < 0)
		HGOTO_ERROR(H5E_BTREE, H5E_CANTSPLIT, H5B_INS_ERROR, "unable to split node")
	    if(idx < bt->nchildren) {
		tmp_bt = bt;
                tmp_bt_flags_ptr = &bt_ud->cache_flags;
	    } else {
		idx -= bt->nchildren;
		tmp_bt = split_bt_ud->bt;
                tmp_bt_flags_ptr = &split_bt_ud->cache_flags;
	    }
	} /* end if */
        else {
	    tmp_bt = bt;
            tmp_bt_flags_ptr = &bt_ud->cache_flags;
	} /* end else */

	/* Insert the child */
	if(H5B__insert_child(tmp_bt, tmp_bt_flags_ptr, idx, new_child_bt_ud.addr, my_ins, md_key) < 0)
	    HGOTO_ERROR(H5E_BTREE, H5E_CANTINSERT, H5B_INS_ERROR, "can't insert child")
    } /* end else-if */

    /*
     * If this node split, return the mid key (the one that is shared
     * by the left and right node).
     */
    if(split_bt_ud->bt) {
	HDmemcpy(md_key, H5B_NKEY(split_bt_ud->bt, shared, 0), type->sizeof_nkey);
	ret_value = H5B_INS_RIGHT;
#ifdef H5B_DEBUG
	/*
	 * The max key in the original left node must be equal to the min key
	 * in the new node.
	 */
	cmp = (type->cmp2)(H5B_NKEY(bt, shared, bt->nchildren), udata,
			    H5B_NKEY(split_bt_ud->bt, shared, 0));
	HDassert(0 == cmp);
#endif
    } /* end if */
    else
	ret_value = H5B_INS_NOOP;

done:
    if(child_bt_ud.bt)
        if(H5AC_unprotect(f, H5AC_BT, child_bt_ud.addr, child_bt_ud.bt, child_bt_ud.cache_flags) < 0)
            HDONE_ERROR(H5E_BTREE, H5E_CANTUNPROTECT, H5B_INS_ERROR, "unable to unprotect child")

    if(new_child_bt_ud.bt)
        if(H5AC_unprotect(f, H5AC_BT, new_child_bt_ud.addr, new_child_bt_ud.bt, new_child_bt_ud.cache_flags) < 0)
            HDONE_ERROR(H5E_BTREE, H5E_CANTUNPROTECT, H5B_INS_ERROR, "unable to unprotect new child")

    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5B_insert_helper() */


/*-------------------------------------------------------------------------
 * Function:	H5B__iterate_helper
 *
 * Purpose:	Calls the list callback for each leaf node of the
 *		B-tree, passing it the caller's UDATA structure.
 *
 * Return:	Non-negative on success/Negative on failure
 *
 * Programmer:	Robb Matzke
 *		matzke@llnl.gov
 *		Jun 23 1997
 *
 *-------------------------------------------------------------------------
 */
static herr_t
H5B__iterate_helper(H5F_t *f, const H5B_class_t *type, haddr_t addr,
    H5B_operator_t op, void *udata)
{
    H5B_t               *bt = NULL;     /* Pointer to current B-tree node */
    H5UC_t	        *rc_shared;     /* Ref-counted shared info */
    H5B_shared_t        *shared;        /* Pointer to shared B-tree info */
    H5B_cache_ud_t      cache_udata;    /* User-data for metadata cache callback */
    unsigned            u;              /* Local index variable */
    herr_t              ret_value = H5_ITER_CONT; /* Return value */

    FUNC_ENTER_STATIC

    /*
     * Check arguments.
     */
    HDassert(f);
    HDassert(type);
    HDassert(H5F_addr_defined(addr));
    HDassert(op);
    HDassert(udata);

    /* Get shared info for B-tree */
    if(NULL == (rc_shared = (type->get_shared)(f, udata)))
        HGOTO_ERROR(H5E_BTREE, H5E_CANTGET, FAIL, "can't retrieve B-tree's shared ref. count object")
    shared = (H5B_shared_t *)H5UC_GET_OBJ(rc_shared);
    HDassert(shared);

    /* Protect the initial/current node */
    cache_udata.f = f;
    cache_udata.type = type;
    cache_udata.rc_shared = rc_shared;
    if(NULL == (bt = (H5B_t *)H5AC_protect(f, H5AC_BT, addr, &cache_udata, H5AC__READ_ONLY_FLAG)))
        HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, H5_ITER_ERROR, "unable to load B-tree node")

    /* Iterate over node's children */
    for(u = 0; u < bt->nchildren && ret_value == H5_ITER_CONT; u++) {
        if(bt->level > 0)
            ret_value = H5B__iterate_helper(f, type, bt->child[u], op, udata);
        else
            ret_value = (*op)(f, H5B_NKEY(bt, shared, u), bt->child[u], H5B_NKEY(bt, shared, u + 1), udata);
        if(ret_value < 0)
            HERROR(H5E_BTREE, H5E_BADITER, "B-tree iteration failed");
    } /* end for */

done:
    if(bt && H5AC_unprotect(f, H5AC_BT, addr, bt, H5AC__NO_FLAGS_SET) < 0)
        HDONE_ERROR(H5E_BTREE, H5E_CANTUNPROTECT, H5_ITER_ERROR, "unable to release B-tree node")

    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5B__iterate_helper() */


/*-------------------------------------------------------------------------
 * Function:	H5B_iterate
 *
 * Purpose:	Calls the list callback for each leaf node of the
 *		B-tree, passing it the UDATA structure.
 *
 * Return:	Non-negative on success/Negative on failure
 *
 * Programmer:	Robb Matzke
 *		matzke@llnl.gov
 *		Jun 23 1997
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5B_iterate(H5F_t *f, const H5B_class_t *type, haddr_t addr,
    H5B_operator_t op, void *udata)
{
    herr_t ret_value = FAIL;            /* Return value */

    FUNC_ENTER_NOAPI_NOERR

    /*
     * Check arguments.
     */
    HDassert(f);
    HDassert(type);
    HDassert(H5F_addr_defined(addr));
    HDassert(op);
    HDassert(udata);

    /* Iterate over the B-tree records */
    if((ret_value = H5B__iterate_helper(f, type, addr, op, udata)) < 0)
        HERROR(H5E_BTREE, H5E_BADITER, "B-tree iteration failed");

    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5B_iterate() */


/*-------------------------------------------------------------------------
 * Function:	H5B__remove_helper
 *
 * Purpose:	The recursive part of removing an item from a B-tree.  The
 *		sub B-tree that is being considered is located at ADDR and
 *		the item to remove is described by UDATA.  If the removed
 *		item falls at the left or right end of the current level then
 *		it might be necessary to adjust the left and/or right keys
 *		(LT_KEY and/or RT_KEY) to to indicate that they changed by
 * 		setting LT_KEY_CHANGED and/or RT_KEY_CHANGED.
 *
 * Return:	Success:	A B-tree operation, see comments for
 *				H5B_ins_t declaration.  This function is
 *				called recursively and the return value
 *				influences the actions of the caller. It is
 *				also called by H5B_remove().
 *
 *		Failure:	H5B_INS_ERROR, a negative value.
 *
 * Programmer:	Robb Matzke
 *              Wednesday, September 16, 1998
 *
 *-------------------------------------------------------------------------
 */
static H5B_ins_t
H5B__remove_helper(H5F_t *f, haddr_t addr, const H5B_class_t *type, int level,
    uint8_t *lt_key/*out*/, hbool_t *lt_key_changed/*out*/, void *udata,
    uint8_t *rt_key/*out*/, hbool_t *rt_key_changed/*out*/)
{
    H5B_t	*bt = NULL, *sibling = NULL;
    unsigned	bt_flags = H5AC__NO_FLAGS_SET;
    H5UC_t	*rc_shared;             /* Ref-counted shared info */
    H5B_shared_t *shared;               /* Pointer to shared B-tree info */
    H5B_cache_ud_t cache_udata;         /* User-data for metadata cache callback */
    unsigned    idx = 0, lt = 0, rt;    /* Final, left & right indices */
    int         cmp = 1;                /* Key comparison value */
    H5B_ins_t	ret_value = H5B_INS_ERROR;

    FUNC_ENTER_STATIC

    HDassert(f);
    HDassert(H5F_addr_defined(addr));
    HDassert(type);
    HDassert(type->decode);
    HDassert(type->cmp3);
    HDassert(lt_key && lt_key_changed);
    HDassert(udata);
    HDassert(rt_key && rt_key_changed);

    /* Get shared info for B-tree */
    if(NULL == (rc_shared = (type->get_shared)(f, udata)))
	HGOTO_ERROR(H5E_BTREE, H5E_CANTGET, H5B_INS_ERROR, "can't retrieve B-tree's shared ref. count object")
    shared = (H5B_shared_t *)H5UC_GET_OBJ(rc_shared);
    HDassert(shared);

    /*
     * Perform a binary search to locate the child which contains the thing
     * for which we're searching.
     */
    cache_udata.f = f;
    cache_udata.type = type;
    cache_udata.rc_shared = rc_shared;
    if(NULL == (bt = (H5B_t *)H5AC_protect(f, H5AC_BT, addr, &cache_udata, H5AC__NO_FLAGS_SET)))
	HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, H5B_INS_ERROR, "unable to load B-tree node")

    rt = bt->nchildren;
    while(lt < rt && cmp) {
	idx = (lt + rt) / 2;
	if((cmp = (type->cmp3)(H5B_NKEY(bt, shared, idx), udata, H5B_NKEY(bt, shared, idx + 1))) < 0)
	    rt = idx;
	else
	    lt = idx + 1;
    } /* end while */
    if(cmp)
	HGOTO_ERROR(H5E_BTREE, H5E_NOTFOUND, H5B_INS_ERROR, "B-tree key not found")

    /*
     * Follow the link to the subtree or to the data node.  The return value
     * will be one of H5B_INS_ERROR, H5B_INS_NOOP, or H5B_INS_REMOVE.
     */
    HDassert(idx < bt->nchildren);
    if(bt->level > 0) {
	/* We're at an internal node -- call recursively */
	if((int)(ret_value = H5B__remove_helper(f, bt->child[idx], type,
                level + 1, H5B_NKEY(bt, shared, idx)/*out*/,
                lt_key_changed/*out*/, udata, H5B_NKEY(bt, shared, idx + 1)/*out*/,
                rt_key_changed/*out*/)) < 0)
	    HGOTO_ERROR(H5E_BTREE, H5E_NOTFOUND, H5B_INS_ERROR, "key not found in subtree")
    } else if(type->remove) {
	/*
	 * We're at a leaf node but the leaf node points to an object that
	 * has a removal method.  Pass the removal request to the pointed-to
	 * object and let it decide how to progress.
	 */
	if((int)(ret_value = (type->remove)(f, bt->child[idx],
                H5B_NKEY(bt, shared, idx), lt_key_changed, udata,
                H5B_NKEY(bt, shared, idx + 1), rt_key_changed)) < 0)
	    HGOTO_ERROR(H5E_BTREE, H5E_NOTFOUND, H5B_INS_ERROR, "key not found in leaf node")
    } else {
	/*
	 * We're at a leaf node which points to an object that has no removal
	 * method.  The best we can do is to leave the object alone but
	 * remove the B-tree reference to the object.
	 */
	*lt_key_changed = FALSE;
	*rt_key_changed = FALSE;
	ret_value = H5B_INS_REMOVE;
    }

    /*
     * Update left and right key dirty bits if the subtree indicates that they
     * have changed.  If the subtree's left key changed and the subtree is the
     * left-most child of the current node then we must update the key in our
     * parent and indicate that it changed.  Similarly, if the right subtree
     * key changed and it's the right most key of this node we must update
     * our right key and indicate that it changed.
     */
    if(*lt_key_changed) {
        HDassert(type->critical_key == H5B_LEFT);
        bt_flags |= H5AC__DIRTIED_FLAG;

        if(idx > 0)
            /* Don't propagate change out of this B-tree node */
            *lt_key_changed = FALSE;
        else
            HDmemcpy(lt_key, H5B_NKEY(bt, shared, idx), type->sizeof_nkey);
    } /* end if */
    if(*rt_key_changed) {
        HDassert(type->critical_key == H5B_RIGHT);
        bt_flags |= H5AC__DIRTIED_FLAG;
        if(idx + 1 < bt->nchildren)
            /* Don't propagate change out of this B-tree node */
            *rt_key_changed = FALSE;
        else
            HDmemcpy(rt_key, H5B_NKEY(bt, shared, idx + 1), type->sizeof_nkey);
    } /* end if */

    /*
     * If the subtree returned H5B_INS_REMOVE then we should remove the
     * subtree entry from the current node.  There are four cases:
     */
    if(H5B_INS_REMOVE == ret_value) {
        /* Clients should not change keys when a node is removed.  This function
         * will handle it as appropriate, based on the value of bt->critical_key
         */
        HDassert(!(*lt_key_changed));
        HDassert(!(*rt_key_changed));

        if(1 == bt->nchildren) {
            /*
             * The subtree is the only child of this node.  Discard both
             * keys and the subtree pointer. Free this node (unless it's the
             * root node) and return H5B_INS_REMOVE.
             */
            /* Only delete the node if it is not the root node.  Note that this
             * "level" is the opposite of bt->level */
            if(level > 0) {
                /* Fix siblings, making sure that the keys remain consistent
                 * between siblings.  Overwrite the key that that is not
                 * "critical" for any child in its node to maintain this
                 * consistency (and avoid breaking key/child consistency) */
                if(H5F_addr_defined(bt->left)) {
                    if(NULL == (sibling = (H5B_t *)H5AC_protect(f, H5AC_BT, bt->left, &cache_udata, H5AC__NO_FLAGS_SET)))
                        HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, H5B_INS_ERROR, "unable to load node from tree")

                    /* Copy right-most key from deleted node to right-most key
                     * in its left neighbor, but only if it is not the critical
                     * key for the right-most child of the left neighbor */
                    if(type->critical_key == H5B_LEFT)
                        HDmemcpy(H5B_NKEY(sibling, shared, sibling->nchildren),
                                H5B_NKEY(bt, shared, 1), type->sizeof_nkey);

                    sibling->right = bt->right;

                    if(H5AC_unprotect(f, H5AC_BT, bt->left, sibling, H5AC__DIRTIED_FLAG) < 0)
                        HGOTO_ERROR(H5E_BTREE, H5E_CANTUNPROTECT, H5B_INS_ERROR, "unable to release node from tree")
                    sibling = NULL;   /* Make certain future references will be caught */
                } /* end if */
                if(H5F_addr_defined(bt->right)) {
                    if(NULL == (sibling = (H5B_t *)H5AC_protect(f, H5AC_BT, bt->right, &cache_udata, H5AC__NO_FLAGS_SET)))
                        HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, H5B_INS_ERROR, "unable to unlink node from tree")

                    /* Copy left-most key from deleted node to left-most key in
                     * its right neighbor, but only if it is not the critical
                     * key for the left-most child of the right neighbor */
                    if(type->critical_key == H5B_RIGHT)
                        HDmemcpy(H5B_NKEY(sibling, shared, 0),
                                H5B_NKEY(bt, shared, 0), type->sizeof_nkey);

                    sibling->left = bt->left;

                    if(H5AC_unprotect(f, H5AC_BT, bt->right, sibling, H5AC__DIRTIED_FLAG) < 0)
                        HGOTO_ERROR(H5E_BTREE, H5E_CANTUNPROTECT, H5B_INS_ERROR, "unable to release node from tree")
                    sibling = NULL;   /* Make certain future references will be caught */
                } /* end if */

                /* Update bt struct */
                bt->left = HADDR_UNDEF;
                bt->right = HADDR_UNDEF;
                bt->nchildren = 0;

                /* Delete the node from disk (via the metadata cache) */
		bt_flags |= H5AC__DIRTIED_FLAG | H5AC__FREE_FILE_SPACE_FLAG;
                H5_CHECK_OVERFLOW(shared->sizeof_rnode, size_t, hsize_t);
                if(H5AC_unprotect(f, H5AC_BT, addr, bt, bt_flags | H5AC__DELETED_FLAG) < 0) {
                    bt = NULL;
                    bt_flags = H5AC__NO_FLAGS_SET;
                    HGOTO_ERROR(H5E_BTREE, H5E_CANTUNPROTECT, H5B_INS_ERROR, "unable to free B-tree node")
                } /* end if */
                bt = NULL;
                bt_flags = H5AC__NO_FLAGS_SET;
            } else {
                /* We removed the last child in the root node, set the level
                 * back to 0 (as well as nchildren) */
                bt->nchildren = 0;
                bt->level = 0;
                bt_flags |= H5AC__DIRTIED_FLAG;
            } /* end else */
        } else if(0 == idx) {
            /*
             * The subtree is the left-most child of this node. We update the
             * key and child arrays and lt_key as appropriate, depending on the
             * status of bt->critical_key.  Return H5B_INS_NOOP.
             */
            if(type->critical_key == H5B_LEFT) {
                /* Slide all keys down 1, update lt_key */
                HDmemmove(H5B_NKEY(bt, shared, 0), H5B_NKEY(bt, shared, 1),
                        bt->nchildren * type->sizeof_nkey);
                HDmemcpy(lt_key, H5B_NKEY(bt, shared, 0), type->sizeof_nkey);
                *lt_key_changed = TRUE;
            } else
                /* Slide all but the leftmost 2 keys down, leaving the leftmost
                 * key intact (the right key of the leftmost child is
                 * overwritten) */
                HDmemmove(H5B_NKEY(bt, shared, 1), H5B_NKEY(bt, shared, 2),
                        (bt->nchildren - 1) * type->sizeof_nkey);

            HDmemmove(bt->child,
                    bt->child + 1,
                    (bt->nchildren - 1) * sizeof(haddr_t));

            bt->nchildren -= 1;
            bt_flags |= H5AC__DIRTIED_FLAG;
            ret_value = H5B_INS_NOOP;
        } else if(idx + 1 == bt->nchildren) {
            /*
             * The subtree is the right-most child of this node. We update the
             * key and child arrays and rt_key as appropriate, depending on the
             * status of bt->critical_key.  Return H5B_INS_NOOP.
             */
            if(type->critical_key == H5B_LEFT)
                /* Slide the rightmost key down one, overwriting the left key of
                 * the deleted (righmost) child */
                HDmemmove(H5B_NKEY(bt, shared, bt->nchildren - 1),
                        H5B_NKEY(bt, shared, bt->nchildren), type->sizeof_nkey);
            else {
                /* Just update rt_key */
                HDmemcpy(rt_key, H5B_NKEY(bt, shared, bt->nchildren - 1),
                        type->sizeof_nkey);
                *rt_key_changed = TRUE;
            } /* end else */

            bt->nchildren -= 1;
            bt_flags |= H5AC__DIRTIED_FLAG;
            ret_value = H5B_INS_NOOP;
        } else {
            /*
             * There are subtrees out of this node to both the left and right of
             * the subtree being removed.  The subtree and its critical key are
             * removed from this node and all keys and nodes to the right are
             * shifted left by one place.  The subtree has already been freed.
             * Return H5B_INS_NOOP.
             */
            if(type->critical_key == H5B_LEFT)
                HDmemmove(H5B_NKEY(bt, shared, idx),
                        H5B_NKEY(bt, shared, idx + 1),
                        (bt->nchildren - idx) * type->sizeof_nkey);
            else
                HDmemmove(H5B_NKEY(bt, shared, idx + 1),
                        H5B_NKEY(bt, shared, idx + 2),
                        (bt->nchildren - 1 - idx) * type->sizeof_nkey);

            HDmemmove(bt->child + idx,
                    bt->child + idx + 1,
                    (bt->nchildren - 1 - idx) * sizeof(haddr_t));

            bt->nchildren -= 1;
            bt_flags |= H5AC__DIRTIED_FLAG;
            ret_value = H5B_INS_NOOP;
        } /* end else */
    } else /* H5B_INS_REMOVE != ret_value */
        ret_value = H5B_INS_NOOP;

    /* Patch keys in neighboring trees if necessary */
    if(*lt_key_changed && H5F_addr_defined(bt->left)) {
        HDassert(type->critical_key == H5B_LEFT);
        HDassert(level > 0);

        /* Update the rightmost key in the left sibling */
        if(NULL == (sibling = (H5B_t *)H5AC_protect(f, H5AC_BT, bt->left, &cache_udata, H5AC__NO_FLAGS_SET)))
            HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, H5B_INS_ERROR, "unable to protect node")

        HDmemcpy(H5B_NKEY(sibling, shared, sibling->nchildren),
                H5B_NKEY(bt, shared, 0), type->sizeof_nkey);

        if(H5AC_unprotect(f, H5AC_BT, bt->left, sibling, H5AC__DIRTIED_FLAG) < 0)
            HGOTO_ERROR(H5E_BTREE, H5E_CANTUNPROTECT, H5B_INS_ERROR, "unable to release node from tree")
        sibling = NULL;   /* Make certain future references will be caught */
    } /* end if */
    else if(*rt_key_changed && H5F_addr_defined(bt->right)) {
        HDassert(type->critical_key == H5B_RIGHT);
        HDassert(level > 0);

        /* Update the lefttmost key in the right sibling */
        if(NULL == (sibling = (H5B_t *)H5AC_protect(f, H5AC_BT, bt->right, &cache_udata, H5AC__NO_FLAGS_SET)))
            HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, H5B_INS_ERROR, "unable to protect node")

        HDmemcpy(H5B_NKEY(sibling, shared, 0),
                H5B_NKEY(bt, shared, bt->nchildren), type->sizeof_nkey);

        if(H5AC_unprotect(f, H5AC_BT, bt->right, sibling, H5AC__DIRTIED_FLAG) < 0)
            HGOTO_ERROR(H5E_BTREE, H5E_CANTUNPROTECT, H5B_INS_ERROR, "unable to release node from tree")
        sibling = NULL;   /* Make certain future references will be caught */
    } /* end else */

done:
    if(bt && H5AC_unprotect(f, H5AC_BT, addr, bt, bt_flags) < 0)
	HDONE_ERROR(H5E_BTREE, H5E_CANTUNPROTECT, H5B_INS_ERROR, "unable to release node")

    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5B__remove_helper() */


/*-------------------------------------------------------------------------
 * Function:	H5B_remove
 *
 * Purpose:	Removes an item from a B-tree.
 *
 * Note:	The current version does not attempt to rebalance the tree.
 *              (Read the paper Yao & Lehman paper for details on why)
 *
 * Return:	Non-negative on success/Negative on failure (failure includes
 *		not being able to find the object which is to be removed).
 *
 * Programmer:	Robb Matzke
 *              Wednesday, September 16, 1998
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5B_remove(H5F_t *f, const H5B_class_t *type, haddr_t addr, void *udata)
{
    /* These are defined this way to satisfy alignment constraints */
    uint64_t	_lt_key[128], _rt_key[128];
    uint8_t	*lt_key = (uint8_t*)_lt_key;	/*left key*/
    uint8_t	*rt_key = (uint8_t*)_rt_key;	/*right key*/
    hbool_t	lt_key_changed = FALSE;		/*left key changed?*/
    hbool_t	rt_key_changed = FALSE;		/*right key changed?*/
    herr_t      ret_value = SUCCEED;            /* Return value */

    FUNC_ENTER_NOAPI(FAIL)

    /* Check args */
    HDassert(f);
    HDassert(type);
    HDassert(type->sizeof_nkey <= sizeof _lt_key);
    HDassert(H5F_addr_defined(addr));

    /* The actual removal */
    if(H5B_INS_ERROR == H5B__remove_helper(f, addr, type, 0, lt_key, &lt_key_changed, udata, rt_key, &rt_key_changed))
	HGOTO_ERROR(H5E_BTREE, H5E_CANTINIT, FAIL, "unable to remove entry from B-tree")

#ifdef H5B_DEBUG
    H5B__assert(f, addr, type, udata);
#endif
done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5B_remove() */


/*-------------------------------------------------------------------------
 * Function:	H5B_delete
 *
 * Purpose:	Deletes an entire B-tree from the file, calling the 'remove'
 *              callbacks for each node.
 *
 * Return:	Non-negative on success/Negative on failure
 *
 * Programmer:	Quincey Koziol
 *              Thursday, March 20, 2003
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5B_delete(H5F_t *f, const H5B_class_t *type, haddr_t addr, void *udata)
{
    H5B_t	*bt = NULL;             /* B-tree node being operated on */
    H5UC_t	*rc_shared;             /* Ref-counted shared info */
    H5B_shared_t *shared;               /* Pointer to shared B-tree info */
    H5B_cache_ud_t cache_udata;         /* User-data for metadata cache callback */
    unsigned    u;                      /* Local index variable */
    herr_t      ret_value = SUCCEED;    /* Return value */

    FUNC_ENTER_NOAPI(FAIL)

    /* Check args */
    HDassert(f);
    HDassert(type);
    HDassert(H5F_addr_defined(addr));

    /* Get shared info for B-tree */
    if(NULL == (rc_shared = (type->get_shared)(f, udata)))
        HGOTO_ERROR(H5E_BTREE, H5E_CANTGET, FAIL, "can't retrieve B-tree's shared ref. count object")
    shared = (H5B_shared_t *)H5UC_GET_OBJ(rc_shared);
    HDassert(shared);

    /* Lock this B-tree node into memory for now */
    cache_udata.f = f;
    cache_udata.type = type;
    cache_udata.rc_shared = rc_shared;
    if(NULL == (bt = (H5B_t *)H5AC_protect(f, H5AC_BT, addr, &cache_udata, H5AC__NO_FLAGS_SET)))
        HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to load B-tree node")

    /* Iterate over all children in tree, deleting them */
    if(bt->level > 0) {
        /* Iterate over all children in node, deleting them */
        for(u = 0; u < bt->nchildren; u++)
            if(H5B_delete(f, type, bt->child[u], udata) < 0)
                HGOTO_ERROR(H5E_BTREE, H5E_CANTLIST, FAIL, "unable to delete B-tree node")

    } /* end if */
    else {
        hbool_t lt_key_changed, rt_key_changed; /* Whether key changed (unused here, just for callback) */

        /* Check for removal callback */
        if(type->remove) {
            /* Iterate over all entries in node, calling callback */
            for(u = 0; u < bt->nchildren; u++) {
                /* Call user's callback for each entry */
                if((type->remove)(f, bt->child[u], H5B_NKEY(bt, shared, u),
                        &lt_key_changed, udata, H5B_NKEY(bt, shared, u + 1),
                        &rt_key_changed) < H5B_INS_NOOP)
                    HGOTO_ERROR(H5E_BTREE, H5E_NOTFOUND, FAIL, "can't remove B-tree node")
            } /* end for */
        } /* end if */
    } /* end else */

done:
    if(bt && H5AC_unprotect(f, H5AC_BT, addr, bt, H5AC__DELETED_FLAG | H5AC__FREE_FILE_SPACE_FLAG) < 0)
        HDONE_ERROR(H5E_BTREE, H5E_CANTUNPROTECT, FAIL, "unable to release B-tree node in cache")

    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5B_delete() */


/*-------------------------------------------------------------------------
 * Function:	H5B_shared_new
 *
 * Purpose:	Allocates & constructs a shared v1 B-tree struct for client.
 *
 * Return:	Success:	non-NULL pointer to struct allocated
 *		Failure:	NULL
 *
 * Programmer:	Quincey Koziol
 *		koziol@hdfgroup.org
 *		May 27 2008
 *
 *-------------------------------------------------------------------------
 */
H5B_shared_t *
H5B_shared_new(const H5F_t *f, const H5B_class_t *type, size_t sizeof_rkey)
{
    H5B_shared_t *shared = NULL;        /* New shared B-tree struct */
    size_t	u;                      /* Local index variable */
    H5B_shared_t *ret_value = NULL;     /* Return value */

    FUNC_ENTER_NOAPI(NULL)

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

    /* Allocate space for the shared structure */
    if(NULL == (shared = H5FL_CALLOC(H5B_shared_t)))
	HGOTO_ERROR(H5E_BTREE, H5E_CANTALLOC, NULL, "memory allocation failed for shared B-tree info")

    /* Set up the "global" information for this file's groups */
    shared->type = type;
    shared->two_k = 2 * H5F_KVALUE(f, type);
    shared->sizeof_addr = H5F_SIZEOF_ADDR(f);
    shared->sizeof_len = H5F_SIZEOF_SIZE(f);
    shared->sizeof_rkey = sizeof_rkey;
    HDassert(shared->sizeof_rkey);
    shared->sizeof_keys = (shared->two_k + 1) * type->sizeof_nkey;
    shared->sizeof_rnode = ((size_t)H5B_SIZEOF_HDR(f) + /*node header	*/
	    shared->two_k * H5F_SIZEOF_ADDR(f) +	/*child pointers */
	    (shared->two_k + 1) * shared->sizeof_rkey);	/*keys		*/
    HDassert(shared->sizeof_rnode);

    /* Allocate and clear shared buffers */
    if(NULL == (shared->page = H5FL_BLK_MALLOC(page, shared->sizeof_rnode)))
        HGOTO_ERROR(H5E_BTREE, H5E_CANTALLOC, NULL, "memory allocation failed for B-tree page")
    HDmemset(shared->page, 0, shared->sizeof_rnode);

    if(NULL == (shared->nkey = H5FL_SEQ_MALLOC(size_t, (size_t)(shared->two_k + 1))))
        HGOTO_ERROR(H5E_BTREE, H5E_CANTALLOC, NULL, "memory allocation failed for B-tree native keys")

    /* Initialize the offsets into the native key buffer */
    for(u = 0; u < (shared->two_k + 1); u++)
        shared->nkey[u] = u * type->sizeof_nkey;

    /* Set return value */
    ret_value = shared;

done:
    if(NULL == ret_value)
        if(shared) {
            if(shared->page)
                shared->page = H5FL_BLK_FREE(page, shared->page);
            if(shared->nkey)
                shared->nkey = H5FL_SEQ_FREE(size_t, shared->nkey);
            shared = H5FL_FREE(H5B_shared_t, shared);
        } /* end if */

    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5B_shared_new() */


/*-------------------------------------------------------------------------
 * Function:	H5B_shared_free
 *
 * Purpose:	Free B-tree shared info
 *
 * Return:	Non-negative on success/Negative on failure
 *
 * Programmer:	Quincey Koziol
 *              Tuesday, May 27, 2008
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5B_shared_free(void *_shared)
{
    H5B_shared_t *shared = (H5B_shared_t *)_shared;

    FUNC_ENTER_NOAPI_NOINIT_NOERR

    /* Free the raw B-tree node buffer */
    shared->page = H5FL_BLK_FREE(page, shared->page);

    /* Free the B-tree native key offsets buffer */
    shared->nkey = H5FL_SEQ_FREE(size_t, shared->nkey);

    /* Free the shared B-tree info */
    shared = H5FL_FREE(H5B_shared_t, shared);

    FUNC_LEAVE_NOAPI(SUCCEED)
} /* end H5B_shared_free() */


/*-------------------------------------------------------------------------
 * Function:	H5B__copy
 *
 * Purpose:	Deep copies an existing H5B_t node.
 *
 * Return:	Success:	Pointer to H5B_t object.
 *
 * 		Failure:	NULL
 *
 * Programmer:	Quincey Koziol
 *		koziol@ncsa.uiuc.edu
 *		Apr 18 2000
 *
 *-------------------------------------------------------------------------
 */
static H5B_t *
H5B__copy(const H5B_t *old_bt)
{
    H5B_t		*new_node = NULL;
    H5B_shared_t        *shared;        /* Pointer to shared B-tree info */
    H5B_t		*ret_value = NULL;      /* Return value */

    FUNC_ENTER_STATIC

    /*
     * Check arguments.
     */
    HDassert(old_bt);
    shared = (H5B_shared_t *)H5UC_GET_OBJ(old_bt->rc_shared);
    HDassert(shared);

    /* Allocate memory for the new H5B_t object */
    if(NULL == (new_node = H5FL_MALLOC(H5B_t)))
        HGOTO_ERROR(H5E_BTREE, H5E_CANTALLOC, NULL, "memory allocation failed for B-tree root node")

    /* Copy the main structure */
    HDmemcpy(new_node, old_bt, sizeof(H5B_t));

    /* Reset cache info */
    HDmemset(&new_node->cache_info, 0, sizeof(H5AC_info_t));

    if(NULL == (new_node->native = H5FL_BLK_MALLOC(native_block, shared->sizeof_keys)) ||
            NULL == (new_node->child = H5FL_SEQ_MALLOC(haddr_t, (size_t)shared->two_k)))
        HGOTO_ERROR(H5E_BTREE, H5E_CANTALLOC, NULL, "memory allocation failed for B-tree root node")

    /* Copy the other structures */
    HDmemcpy(new_node->native, old_bt->native, shared->sizeof_keys);
    HDmemcpy(new_node->child, old_bt->child, (sizeof(haddr_t) * shared->two_k));

    /* Increment the ref-count on the raw page */
    H5UC_INC(new_node->rc_shared);

    /* Set return value */
    ret_value = new_node;

done:
    if(NULL == ret_value) {
        if(new_node) {
	    new_node->native = H5FL_BLK_FREE(native_block, new_node->native);
	    new_node->child = H5FL_SEQ_FREE(haddr_t, new_node->child);
	    new_node = H5FL_FREE(H5B_t, new_node);
        } /* end if */
    } /* end if */

    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5B__copy() */


/*-------------------------------------------------------------------------
 * Function:	H5B__get_info_helper
 *
 * Purpose:	Walks the B-tree nodes, getting information for all of them.
 *
 * Return:	Non-negative on success/Negative on failure
 *
 * Programmer:	Quincey Koziol
 *		koziol@hdfgroup.org
 *		Jun  3 2008
 *
 *-------------------------------------------------------------------------
 */
static herr_t
H5B__get_info_helper(H5F_t *f, const H5B_class_t *type, haddr_t addr,
    const H5B_info_ud_t *info_udata)
{
    H5B_t *bt = NULL;           /* Pointer to current B-tree node */
    H5UC_t *rc_shared;          /* Ref-counted shared info */
    H5B_shared_t *shared;       /* Pointer to shared B-tree info */
    H5B_cache_ud_t cache_udata; /* User-data for metadata cache callback */
    unsigned level;		/* Node level			     */
    size_t sizeof_rnode;	/* Size of raw (disk) node	     */
    haddr_t next_addr;          /* Address of next node to the right */
    haddr_t left_child;         /* Address of left-most child in node */
    herr_t ret_value = SUCCEED; /* Return value */

    FUNC_ENTER_STATIC

    /*
     * Check arguments.
     */
    HDassert(f);
    HDassert(type);
    HDassert(H5F_addr_defined(addr));
    HDassert(info_udata);
    HDassert(info_udata->bt_info);
    HDassert(info_udata->udata);

    /* Get shared info for B-tree */
    if(NULL == (rc_shared = (type->get_shared)(f, info_udata->udata)))
	HGOTO_ERROR(H5E_BTREE, H5E_CANTGET, FAIL, "can't retrieve B-tree's shared ref. count object")
    shared = (H5B_shared_t *)H5UC_GET_OBJ(rc_shared);
    HDassert(shared);

    /* Get the raw node size for iteration */
    sizeof_rnode = shared->sizeof_rnode;

    /* Protect the initial/current node */
    cache_udata.f = f;
    cache_udata.type = type;
    cache_udata.rc_shared = rc_shared;
    if(NULL == (bt = (H5B_t *)H5AC_protect(f, H5AC_BT, addr, &cache_udata, H5AC__READ_ONLY_FLAG)))
	HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to load B-tree node")

    /* Cache information from this node */
    left_child = bt->child[0];
    next_addr = bt->right;
    level = bt->level;

    /* Update B-tree info */
    info_udata->bt_info->size += sizeof_rnode;
    info_udata->bt_info->num_nodes++;

    /* Release current node */
    if(H5AC_unprotect(f, H5AC_BT, addr, bt, H5AC__NO_FLAGS_SET) < 0)
        HGOTO_ERROR(H5E_BTREE, H5E_CANTUNPROTECT, FAIL, "unable to release B-tree node")
    bt = NULL;

    /*
     * Follow the right-sibling pointer from node to node until we've
     *      processed all nodes.
     */
    while(H5F_addr_defined(next_addr)) {
        /* Protect the next node to the right */
        addr = next_addr;
        if(NULL == (bt = (H5B_t *)H5AC_protect(f, H5AC_BT, addr, &cache_udata, H5AC__READ_ONLY_FLAG)))
            HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "B-tree node")

        /* Cache information from this node */
        next_addr = bt->right;

        /* Update B-tree info */
        info_udata->bt_info->size += sizeof_rnode;
        info_udata->bt_info->num_nodes++;

        /* Unprotect node */
        if(H5AC_unprotect(f, H5AC_BT, addr, bt, H5AC__NO_FLAGS_SET) < 0)
            HGOTO_ERROR(H5E_BTREE, H5E_CANTUNPROTECT, FAIL, "unable to release B-tree node")
        bt = NULL;
    } /* end while */

    /* Check for another "row" of B-tree nodes to iterate over */
    if(level > 0) {
	/* Keep following the left-most child until we reach a leaf node. */
	if(H5B__get_info_helper(f, type, left_child, info_udata) < 0)
	    HGOTO_ERROR(H5E_BTREE, H5E_CANTLIST, FAIL, "unable to list B-tree node")
    } /* end if */

done:
    if(bt && H5AC_unprotect(f, H5AC_BT, addr, bt, H5AC__NO_FLAGS_SET) < 0)
        HDONE_ERROR(H5E_BTREE, H5E_CANTUNPROTECT, FAIL, "unable to release B-tree node")

    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5B__get_info_helper() */


/*-------------------------------------------------------------------------
 * Function:    H5B_get_info
 *
 * Purpose:     Return the amount of storage used for the btree.
 *
 * Return:      Non-negative on success/Negative on failure
 *
 * Programmer:  Vailin Choi
 *              June 19, 2007
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5B_get_info(H5F_t *f, const H5B_class_t *type, haddr_t addr,
    H5B_info_t *bt_info, H5B_operator_t op, void *udata)
{
    H5B_info_ud_t       info_udata;     /* User-data for B-tree size iteration */
    herr_t		ret_value = SUCCEED;      /* Return value */

    FUNC_ENTER_NOAPI(FAIL)

    /*
     * Check arguments.
     */
    HDassert(f);
    HDassert(type);
    HDassert(bt_info);
    HDassert(H5F_addr_defined(addr));
    HDassert(udata);

    /* Portably initialize B-tree info struct */
    HDmemset(bt_info, 0, sizeof(*bt_info));

    /* Set up internal user-data for the B-tree 'get info' helper routine */
    info_udata.bt_info = bt_info;
    info_udata.udata = udata;

    /* Iterate over the B-tree nodes */
    if(H5B__get_info_helper(f, type, addr, &info_udata) < 0)
        HGOTO_ERROR(H5E_BTREE, H5E_BADITER, FAIL, "B-tree iteration failed")

    /* Iterate over the B-tree records, making any "leaf" callbacks */
    /* (Only if operator defined) */
    if(op)
        if((ret_value = H5B__iterate_helper(f, type, addr, op, udata)) < 0)
            HERROR(H5E_BTREE, H5E_BADITER, "B-tree iteration failed");

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5B_get_info() */


/*-------------------------------------------------------------------------
 * Function:    H5B_valid
 *
 * Purpose:     Attempt to load a B-tree node.
 *
 * Return:      Non-negative on success/Negative on failure
 *
 * Programmer:  Neil Fortner
 *              March 17, 2009
 *
 *-------------------------------------------------------------------------
 */
htri_t
H5B_valid(H5F_t *f, const H5B_class_t *type, haddr_t addr)
{
    H5B_t               *bt = NULL;             /* The B-tree */
    H5UC_t              *rc_shared;             /* Ref-counted shared info */
    H5B_shared_t        *shared;                /* Pointer to shared B-tree info */
    H5B_cache_ud_t      cache_udata;            /* User-data for metadata cache callback */
    htri_t		ret_value = SUCCEED;    /* Return value */

    FUNC_ENTER_NOAPI(FAIL)

    /*
     * Check arguments.
     */
    HDassert(f);
    HDassert(type);

    if(!H5F_addr_defined(addr))
        HGOTO_ERROR(H5E_BTREE, H5E_BADVALUE, FAIL, "address is undefined")

    /* Get shared info for B-tree */
    if(NULL == (rc_shared = (type->get_shared)(f, NULL)))
	HGOTO_ERROR(H5E_BTREE, H5E_CANTGET, FAIL, "can't retrieve B-tree's shared ref. count object")
    shared = (H5B_shared_t *)H5UC_GET_OBJ(rc_shared);
    HDassert(shared);

    /*
     * Load the tree node.
     */
    cache_udata.f = f;
    cache_udata.type = type;
    cache_udata.rc_shared = rc_shared;
    if(NULL == (bt = (H5B_t *)H5AC_protect(f, H5AC_BT, addr, &cache_udata, H5AC__READ_ONLY_FLAG)))
	HGOTO_ERROR(H5E_BTREE, H5E_CANTPROTECT, FAIL, "unable to protect B-tree node")

done:
    /* Release the node */
    if(bt && H5AC_unprotect(f, H5AC_BT, addr, bt, H5AC__NO_FLAGS_SET) < 0)
        HDONE_ERROR(H5E_BTREE, H5E_CANTUNPROTECT, FAIL, "unable to release B-tree node")

    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5B_valid() */


/*-------------------------------------------------------------------------
 * Function:    H5B__node_dest
 *
 * Purpose:     Destroy/release a B-tree node
 *
 * Return:      Success:        SUCCEED
 *              Failure:        FAIL
 *
 * Programmer:  Quincey Koziol
 *              koziol@hdfgroup.org
 *              Mar 26, 2008
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5B__node_dest(H5B_t *bt)
{
    FUNC_ENTER_PACKAGE_NOERR

    /* check arguments */
    HDassert(bt);
    HDassert(bt->rc_shared);

    bt->child = H5FL_SEQ_FREE(haddr_t, bt->child);
    bt->native = H5FL_BLK_FREE(native_block, bt->native);
    H5UC_DEC(bt->rc_shared);
    bt = H5FL_FREE(H5B_t, bt);

    FUNC_LEAVE_NOAPI(SUCCEED)
} /* end H5B__node_dest() */