summaryrefslogtreecommitdiffstats
path: root/src/H5HFcache.c
blob: f8829f2d043e4b4f8b8d9dab4f7346e76752cf0f (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
/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
 * 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 files COPYING and Copyright.html.  COPYING can be found at the root   *
 * of the source code distribution tree; Copyright.html can be found at the  *
 * root level of an installed copy of the electronic HDF5 document set and   *
 * is linked from the top-level documents page.  It can also be found at     *
 * http://hdfgroup.org/HDF5/doc/Copyright.html.  If you do not have          *
 * access to either file, you may request a copy from help@hdfgroup.org.     *
 * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */

/*-------------------------------------------------------------------------
 *
 * Created:		H5HFcache.c
 *			Feb 24 2006
 *			Quincey Koziol <koziol@ncsa.uiuc.edu>
 *
 * Purpose:		Implement fractal heap metadata cache methods.
 *
 *-------------------------------------------------------------------------
 */

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

#define H5HF_PACKAGE		/*suppress error about including H5HFpkg  */


/***********/
/* Headers */
/***********/
#include "H5private.h"		/* Generic Functions			*/
#include "H5ACprivate.h"	/* Metadata cache			*/
#include "H5Eprivate.h"		/* Error handling		  	*/
#include "H5HFpkg.h"		/* Fractal heaps			*/
#include "H5MFprivate.h"	/* File memory management		*/
#include "H5MMprivate.h"	/* Memory management			*/
#include "H5Vprivate.h"		/* Vectors and arrays 			*/
#include "H5WBprivate.h"        /* Wrapped Buffers                      */


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

/* Fractal heap format version #'s */
#define H5HF_HDR_VERSION        0               /* Header */
#define H5HF_DBLOCK_VERSION     0               /* Direct block */
#define H5HF_IBLOCK_VERSION     0               /* Indirect block */

/* Size of stack buffer for serialized headers */
#define H5HF_HDR_BUF_SIZE       512

/* Size of stack buffer for serialized indirect blocks */
#define H5HF_IBLOCK_BUF_SIZE    4096


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


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


/********************/
/* Local Prototypes */
/********************/

/* Local encode/decode routines */
static herr_t H5HF_dtable_encode(H5F_t *f, uint8_t **pp, const H5HF_dtable_t *dtable);
static herr_t H5HF_dtable_decode(H5F_t *f, const uint8_t **pp, H5HF_dtable_t *dtable);

/* Metadata cache (H5AC) callbacks */
static H5HF_hdr_t *H5HF_cache_hdr_load(H5F_t *f, hid_t dxpl_id, haddr_t addr, void *udata);
static herr_t H5HF_cache_hdr_flush(H5F_t *f, hid_t dxpl_id, hbool_t destroy, haddr_t addr, H5HF_hdr_t *hdr, unsigned UNUSED * flags_ptr);
static herr_t H5HF_cache_hdr_dest(H5F_t *f, H5HF_hdr_t *hdr);
static herr_t H5HF_cache_hdr_clear(H5F_t *f, H5HF_hdr_t *hdr, hbool_t destroy);
static herr_t H5HF_cache_hdr_size(const H5F_t *f, const H5HF_hdr_t *hdr, size_t *size_ptr);
static H5HF_indirect_t *H5HF_cache_iblock_load(H5F_t *f, hid_t dxpl_id, haddr_t addr, void *udata);
static herr_t H5HF_cache_iblock_flush(H5F_t *f, hid_t dxpl_id, hbool_t destroy, haddr_t addr, H5HF_indirect_t *iblock, unsigned UNUSED * flags_ptr);
static herr_t H5HF_cache_iblock_dest(H5F_t *f, H5HF_indirect_t *iblock);
static herr_t H5HF_cache_iblock_clear(H5F_t *f, H5HF_indirect_t *iblock, hbool_t destroy);
static herr_t H5HF_cache_iblock_size(const H5F_t *f, const H5HF_indirect_t *iblock, size_t *size_ptr);
static H5HF_direct_t *H5HF_cache_dblock_load(H5F_t *f, hid_t dxpl_id, haddr_t addr, void *udata);
static herr_t H5HF_cache_dblock_flush(H5F_t *f, hid_t dxpl_id, hbool_t destroy, haddr_t addr, H5HF_direct_t *dblock, unsigned UNUSED * flags_ptr);
static herr_t H5HF_cache_dblock_dest(H5F_t *f, H5HF_direct_t *dblock);
static herr_t H5HF_cache_dblock_clear(H5F_t *f, H5HF_direct_t *dblock, hbool_t destroy);
static herr_t H5HF_cache_dblock_size(const H5F_t *f, const H5HF_direct_t *dblock, size_t *size_ptr);


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

/* H5HF header inherits cache-like properties from H5AC */
const H5AC_class_t H5AC_FHEAP_HDR[1] = {{
    H5AC_FHEAP_HDR_ID,
    (H5AC_load_func_t)H5HF_cache_hdr_load,
    (H5AC_flush_func_t)H5HF_cache_hdr_flush,
    (H5AC_dest_func_t)H5HF_cache_hdr_dest,
    (H5AC_clear_func_t)H5HF_cache_hdr_clear,
    (H5AC_notify_func_t)NULL,
    (H5AC_size_func_t)H5HF_cache_hdr_size,
}};

/* H5HF indirect block inherits cache-like properties from H5AC */
const H5AC_class_t H5AC_FHEAP_IBLOCK[1] = {{
    H5AC_FHEAP_IBLOCK_ID,
    (H5AC_load_func_t)H5HF_cache_iblock_load,
    (H5AC_flush_func_t)H5HF_cache_iblock_flush,
    (H5AC_dest_func_t)H5HF_cache_iblock_dest,
    (H5AC_clear_func_t)H5HF_cache_iblock_clear,
    (H5AC_notify_func_t)NULL,
    (H5AC_size_func_t)H5HF_cache_iblock_size,
}};

/* H5HF direct block inherits cache-like properties from H5AC */
const H5AC_class_t H5AC_FHEAP_DBLOCK[1] = {{
    H5AC_FHEAP_DBLOCK_ID,
    (H5AC_load_func_t)H5HF_cache_dblock_load,
    (H5AC_flush_func_t)H5HF_cache_dblock_flush,
    (H5AC_dest_func_t)H5HF_cache_dblock_dest,
    (H5AC_clear_func_t)H5HF_cache_dblock_clear,
    (H5AC_notify_func_t)NULL,
    (H5AC_size_func_t)H5HF_cache_dblock_size,
}};


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


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

/* Declare a free list to manage heap direct block data to/from disk */
H5FL_BLK_DEFINE(direct_block);



/*-------------------------------------------------------------------------
 * Function:	H5HF_dtable_decode
 *
 * Purpose:	Decodes the metadata for a doubling table
 *
 * Return:	Success:	Pointer to a new fractal heap
 *
 *		Failure:	NULL
 *
 * Programmer:	Quincey Koziol
 *		koziol@ncsa.uiuc.edu
 *		Feb 27 2006
 *
 *-------------------------------------------------------------------------
 */
static herr_t
H5HF_dtable_decode(H5F_t *f, const uint8_t **pp, H5HF_dtable_t *dtable)
{
    FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5HF_dtable_decode)

    /* Check arguments */
    HDassert(f);
    HDassert(pp && *pp);
    HDassert(dtable);

    /* Table width */
    UINT16DECODE(*pp, dtable->cparam.width);

    /* Starting block size */
    H5F_DECODE_LENGTH(f, *pp, dtable->cparam.start_block_size);

    /* Maximum direct block size */
    H5F_DECODE_LENGTH(f, *pp, dtable->cparam.max_direct_size);

    /* Maximum heap size (as # of bits) */
    UINT16DECODE(*pp, dtable->cparam.max_index);

    /* Starting # of rows in root indirect block */
    UINT16DECODE(*pp, dtable->cparam.start_root_rows);

    /* Address of table */
    H5F_addr_decode(f, pp, &(dtable->table_addr));

    /* Current # of rows in root indirect block */
    UINT16DECODE(*pp, dtable->curr_root_rows);

    FUNC_LEAVE_NOAPI(SUCCEED)
} /* end H5HF_dtable_decode() */


/*-------------------------------------------------------------------------
 * Function:	H5HF_dtable_encode
 *
 * Purpose:	Encodes the metadata for a doubling table
 *
 * Return:	Success:	Pointer to a new fractal heap
 *
 *		Failure:	NULL
 *
 * Programmer:	Quincey Koziol
 *		koziol@ncsa.uiuc.edu
 *		Feb 27 2006
 *
 *-------------------------------------------------------------------------
 */
static herr_t
H5HF_dtable_encode(H5F_t *f, uint8_t **pp, const H5HF_dtable_t *dtable)
{
    FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5HF_dtable_encode)

    /* Check arguments */
    HDassert(f);
    HDassert(pp && *pp);
    HDassert(dtable);

    /* Table width */
    UINT16ENCODE(*pp, dtable->cparam.width);

    /* Starting block size */
    H5F_ENCODE_LENGTH(f, *pp, dtable->cparam.start_block_size);

    /* Maximum direct block size */
    H5F_ENCODE_LENGTH(f, *pp, dtable->cparam.max_direct_size);

    /* Maximum heap size (as # of bits) */
    UINT16ENCODE(*pp, dtable->cparam.max_index);

    /* Starting # of rows in root indirect block */
    UINT16ENCODE(*pp, dtable->cparam.start_root_rows);

    /* Address of root direct/indirect block */
    H5F_addr_encode(f, pp, dtable->table_addr);

    /* Current # of rows in root indirect block */
    UINT16ENCODE(*pp, dtable->curr_root_rows);

    FUNC_LEAVE_NOAPI(SUCCEED)
} /* end H5HF_dtable_encode() */


/*-------------------------------------------------------------------------
 * Function:	H5HF_cache_hdr_load
 *
 * Purpose:	Loads a fractal heap header from the disk.
 *
 * Return:	Success:	Pointer to a new fractal heap
 *		Failure:	NULL
 *
 * Programmer:	Quincey Koziol
 *		koziol@ncsa.uiuc.edu
 *		Feb 24 2006
 *
 *-------------------------------------------------------------------------
 */
static H5HF_hdr_t *
H5HF_cache_hdr_load(H5F_t *f, hid_t dxpl_id, haddr_t addr, void *_udata)
{
    H5HF_hdr_t		*hdr = NULL;     /* Fractal heap info */
    H5HF_hdr_cache_ud_t *udata = (H5HF_hdr_cache_ud_t *)_udata;
    size_t		size;           /* Header size */
    H5WB_t              *wb = NULL;     /* Wrapped buffer for header data */
    uint8_t             hdr_buf[H5HF_HDR_BUF_SIZE]; /* Buffer for header */
    uint8_t		*buf;           /* Pointer to header buffer */
    const uint8_t	*p;             /* Pointer into raw data buffer */
    uint32_t            stored_chksum;  /* Stored metadata checksum value */
    uint32_t            computed_chksum; /* Computed metadata checksum value */
    uint8_t             heap_flags;     /* Status flags for heap */
    H5HF_hdr_t		*ret_value;     /* Return value */

    FUNC_ENTER_NOAPI_NOINIT(H5HF_cache_hdr_load)

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

    /* Allocate space for the fractal heap data structure */
    if(NULL == (hdr = H5HF_hdr_alloc(udata->f)))
	HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL, "memory allocation failed")

    /* Wrap the local buffer for serialized header info */
    if(NULL == (wb = H5WB_wrap(hdr_buf, sizeof(hdr_buf))))
        HGOTO_ERROR(H5E_HEAP, H5E_CANTINIT, NULL, "can't wrap buffer")

    /* Compute the 'base' size of the fractal heap header on disk */
    size = (size_t)H5HF_HEADER_SIZE(hdr);

    /* Get a pointer to a buffer that's large enough for serialized header */
    if(NULL == (buf = (uint8_t *)H5WB_actual(wb, size)))
        HGOTO_ERROR(H5E_HEAP, H5E_NOSPACE, NULL, "can't get actual buffer")

    /* Read header from disk */
    if(H5F_block_read(f, H5FD_MEM_FHEAP_HDR, addr, size, dxpl_id, buf) < 0)
	HGOTO_ERROR(H5E_HEAP, H5E_READERROR, NULL, "can't read fractal heap header")

    /* Get temporary pointer to serialized header */
    p = buf;

    /* Magic number */
    if(HDmemcmp(p, H5HF_HDR_MAGIC, (size_t)H5_SIZEOF_MAGIC))
	HGOTO_ERROR(H5E_HEAP, H5E_CANTLOAD, NULL, "wrong fractal heap header signature")
    p += H5_SIZEOF_MAGIC;

    /* Version */
    if(*p++ != H5HF_HDR_VERSION)
	HGOTO_ERROR(H5E_HEAP, H5E_VERSION, NULL, "wrong fractal heap header version")

    /* General heap information */
    UINT16DECODE(p, hdr->id_len);               /* Heap ID length */
    UINT16DECODE(p, hdr->filter_len);           /* I/O filters' encoded length */

    /* Heap status flags */
    /* (bit 0: "huge" object IDs have wrapped) */
    /* (bit 1: checksum direct blocks) */
    heap_flags = *p++;
    hdr->huge_ids_wrapped = heap_flags & H5HF_HDR_FLAGS_HUGE_ID_WRAPPED;
    hdr->checksum_dblocks = heap_flags & H5HF_HDR_FLAGS_CHECKSUM_DBLOCKS;

    /* "Huge" object information */
    UINT32DECODE(p, hdr->max_man_size);         /* Max. size of "managed" objects */
    H5F_DECODE_LENGTH(udata->f, p, hdr->huge_next_id); /* Next ID to use for "huge" object */
    H5F_addr_decode(udata->f, &p, &hdr->huge_bt2_addr); /* Address of "huge" object tracker B-tree */

    /* "Managed" object free space information */
    H5F_DECODE_LENGTH(udata->f, p, hdr->total_man_free); /* Internal free space in managed direct blocks */
    H5F_addr_decode(udata->f, &p, &hdr->fs_addr);      /* Address of free section header */

    /* Heap statistics */
    H5F_DECODE_LENGTH(udata->f, p, hdr->man_size);
    H5F_DECODE_LENGTH(udata->f, p, hdr->man_alloc_size);
    H5F_DECODE_LENGTH(udata->f, p, hdr->man_iter_off);
    H5F_DECODE_LENGTH(udata->f, p, hdr->man_nobjs);
    H5F_DECODE_LENGTH(udata->f, p, hdr->huge_size);
    H5F_DECODE_LENGTH(udata->f, p, hdr->huge_nobjs);
    H5F_DECODE_LENGTH(udata->f, p, hdr->tiny_size);
    H5F_DECODE_LENGTH(udata->f, p, hdr->tiny_nobjs);

    /* Managed objects' doubling-table info */
    if(H5HF_dtable_decode(hdr->f, &p, &(hdr->man_dtable)) < 0)
        HGOTO_ERROR(H5E_HEAP, H5E_CANTENCODE, NULL, "unable to encode managed obj. doubling table info")

    /* Sanity check */
    /* (allow for checksum not decoded yet) */
    HDassert((size_t)(p - (const uint8_t *)buf) == (size - H5HF_SIZEOF_CHKSUM));

    /* Check for I/O filter information to decode */
    if(hdr->filter_len > 0) {
        size_t filter_info_off;     /* Offset in header of filter information */
        size_t filter_info_size;    /* Size of filter information */
        H5O_pline_t *pline;         /* Pipeline information from the header on disk */

        /* Compute the offset of the filter info in the header */
        filter_info_off = (size_t)(p - (const uint8_t *)buf);

        /* Compute the size of the extra filter information */
        filter_info_size = (size_t)(hdr->sizeof_size     /* Size of size for filtered root direct block */
            + (unsigned)4                       /* Size of filter mask for filtered root direct block */
            + hdr->filter_len);                 /* Size of encoded I/O filter info */

        /* Compute the heap header's size */
        hdr->heap_size = size + filter_info_size;

        /* Re-size current buffer */
        if(NULL == (buf = (uint8_t *)H5WB_actual(wb, hdr->heap_size)))
            HGOTO_ERROR(H5E_HEAP, H5E_NOSPACE, NULL, "can't get actual buffer")

        /* Read in I/O filter information */
        /* (and the checksum) */
        if(H5F_block_read(f, H5FD_MEM_FHEAP_HDR, (addr + filter_info_off), (filter_info_size + H5HF_SIZEOF_CHKSUM), dxpl_id, (buf + filter_info_off)) < 0)
            HGOTO_ERROR(H5E_HEAP, H5E_READERROR, NULL, "can't read fractal heap header's I/O pipeline filter info")

        /* Point at correct offset in header for the filter information */
        p = buf + filter_info_off;

        /* Decode the size of a filtered root direct block */
        H5F_DECODE_LENGTH(udata->f, p, hdr->pline_root_direct_size);

        /* Decode the filter mask for a filtered root direct block */
        UINT32DECODE(p, hdr->pline_root_direct_filter_mask);

        /* Decode I/O filter information */
        if(NULL == (pline = (H5O_pline_t *)H5O_msg_decode(hdr->f, udata->dxpl_id, NULL, H5O_PLINE_ID, p)))
            HGOTO_ERROR(H5E_HEAP, H5E_CANTDECODE, NULL, "can't decode I/O pipeline filters")
        p += hdr->filter_len;

        /* Copy the information into the header's I/O pipeline structure */
        if(NULL == H5O_msg_copy(H5O_PLINE_ID, pline, &(hdr->pline)))
            HGOTO_ERROR(H5E_HEAP, H5E_CANTCOPY, NULL, "can't copy I/O filter pipeline")

        /* Release the space allocated for the I/O pipeline filters */
        H5O_msg_free(H5O_PLINE_ID, pline);
    } /* end if */
    else
        /* Set the heap header's size */
        hdr->heap_size = size;

    /* Compute checksum on entire header */
    /* (including the filter information, if present) */
    computed_chksum = H5_checksum_metadata(buf, (size_t)(p - (const uint8_t *)buf), 0);

    /* Metadata checksum */
    UINT32DECODE(p, stored_chksum);

    /* Sanity check */
    HDassert((size_t)(p - (const uint8_t *)buf) == hdr->heap_size);

    /* Verify checksum */
    if(stored_chksum != computed_chksum)
	HGOTO_ERROR(H5E_HEAP, H5E_BADVALUE, NULL, "incorrect metadata checksum for fractal heap header")

    /* Finish initialization of heap header */
    if(H5HF_hdr_finish_init(hdr) < 0)
	HGOTO_ERROR(H5E_RESOURCE, H5E_CANTINIT, NULL, "can't finish initializing shared fractal heap header")

    /* Set return value */
    ret_value = hdr;

done:
    /* Release resources */
    if(wb && H5WB_unwrap(wb) < 0)
        HDONE_ERROR(H5E_HEAP, H5E_CLOSEERROR, NULL, "can't close wrapped buffer")
    if(!ret_value && hdr)
        if(H5HF_hdr_free(hdr) < 0)
            HDONE_ERROR(H5E_HEAP, H5E_CANTRELEASE, NULL, "unable to release fractal heap header")

    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5HF_cache_hdr_load() */ /*lint !e818 Can't make udata a pointer to const */


/*-------------------------------------------------------------------------
 * Function:	H5HF_cache_hdr_flush
 *
 * Purpose:	Flushes a dirty fractal heap header to disk.
 *
 * Return:	Non-negative on success/Negative on failure
 *
 * Programmer:	Quincey Koziol
 *		koziol@ncsa.uiuc.edu
 *		Feb 24 2006
 *
 *-------------------------------------------------------------------------
 */
static herr_t
H5HF_cache_hdr_flush(H5F_t *f, hid_t dxpl_id, hbool_t destroy, haddr_t addr, H5HF_hdr_t *hdr, unsigned UNUSED * flags_ptr)
{
    H5WB_t *wb = NULL;                  /* Wrapped buffer for header data */
    uint8_t hdr_buf[H5HF_HDR_BUF_SIZE]; /* Buffer for header */
    herr_t ret_value = SUCCEED;         /* Return value */

    FUNC_ENTER_NOAPI_NOINIT(H5HF_cache_hdr_flush)

    /* check arguments */
    HDassert(f);
    HDassert(H5F_addr_defined(addr));
    HDassert(hdr);

    if(hdr->cache_info.is_dirty) {
        uint8_t	*buf;           /* Temporary raw data buffer */
        uint8_t *p;             /* Pointer into raw data buffer */
        size_t	size;           /* Header size on disk */
        uint8_t heap_flags;     /* Status flags for heap */
        uint32_t metadata_chksum; /* Computed metadata checksum value */

        /* Set the shared heap header's file context for this operation */
        hdr->f = f;

        /* Wrap the local buffer for serialized header info */
        if(NULL == (wb = H5WB_wrap(hdr_buf, sizeof(hdr_buf))))
            HGOTO_ERROR(H5E_HEAP, H5E_CANTINIT, FAIL, "can't wrap buffer")

        /* Compute the size of the heap header on disk */
        size = hdr->heap_size;

        /* Get a pointer to a buffer that's large enough for serialized header */
        if(NULL == (buf = (uint8_t *)H5WB_actual(wb, size)))
            HGOTO_ERROR(H5E_HEAP, H5E_NOSPACE, FAIL, "can't get actual buffer")

        /* Get temporary pointer to serialized header */
        p = buf;

        /* Magic number */
        HDmemcpy(p, H5HF_HDR_MAGIC, (size_t)H5_SIZEOF_MAGIC);
        p += H5_SIZEOF_MAGIC;

        /* Version # */
        *p++ = H5HF_HDR_VERSION;

        /* General heap information */
        UINT16ENCODE(p, hdr->id_len);           /* Heap ID length */
        UINT16ENCODE(p, hdr->filter_len);       /* I/O filters' encoded length */

        /* Heap status flags */
        /* (bit 0: "huge" object IDs have wrapped) */
        /* (bit 1: checksum direct blocks) */
        heap_flags = 0;
        heap_flags |= (hdr->huge_ids_wrapped ?  H5HF_HDR_FLAGS_HUGE_ID_WRAPPED : 0);
        heap_flags |= (hdr->checksum_dblocks ?  H5HF_HDR_FLAGS_CHECKSUM_DBLOCKS : 0);
        *p++ = heap_flags;

        /* "Huge" object information */
        UINT32ENCODE(p, hdr->max_man_size);             /* Max. size of "managed" objects */
        H5F_ENCODE_LENGTH(f, p, hdr->huge_next_id);     /* Next ID to use for "huge" object */
        H5F_addr_encode(f, &p, hdr->huge_bt2_addr);     /* Address of "huge" object tracker B-tree */

        /* "Managed" object free space information */
        H5F_ENCODE_LENGTH(f, p, hdr->total_man_free);   /* Internal free space in managed direct blocks */
        H5F_addr_encode(f, &p, hdr->fs_addr);           /* Address of free section header */

        /* Heap statistics */
        H5F_ENCODE_LENGTH(f, p, hdr->man_size);
        H5F_ENCODE_LENGTH(f, p, hdr->man_alloc_size);
        H5F_ENCODE_LENGTH(f, p, hdr->man_iter_off);
        H5F_ENCODE_LENGTH(f, p, hdr->man_nobjs);
        H5F_ENCODE_LENGTH(f, p, hdr->huge_size);
        H5F_ENCODE_LENGTH(f, p, hdr->huge_nobjs);
        H5F_ENCODE_LENGTH(f, p, hdr->tiny_size);
        H5F_ENCODE_LENGTH(f, p, hdr->tiny_nobjs);

        /* Managed objects' doubling-table info */
        if(H5HF_dtable_encode(hdr->f, &p, &(hdr->man_dtable)) < 0)
	    HGOTO_ERROR(H5E_HEAP, H5E_CANTENCODE, FAIL, "unable to encode managed obj. doubling table info")

        /* Check for I/O filter information to encode */
        if(hdr->filter_len > 0) {
            /* Encode the size of a filtered root direct block */
            H5F_ENCODE_LENGTH(f, p, hdr->pline_root_direct_size);

            /* Encode the filter mask for a filtered root direct block */
            UINT32ENCODE(p, hdr->pline_root_direct_filter_mask);

            /* Encode I/O filter information */
            if(H5O_msg_encode(hdr->f, H5O_PLINE_ID, FALSE, p, &(hdr->pline)) < 0)
                HGOTO_ERROR(H5E_HEAP, H5E_CANTENCODE, FAIL, "can't encode I/O pipeline fiters")
            p += hdr->filter_len;
        } /* end if */

        /* Compute metadata checksum */
        metadata_chksum = H5_checksum_metadata(buf, (size_t)(p - buf), 0);

        /* Metadata checksum */
        UINT32ENCODE(p, metadata_chksum);

	/* Write the heap header. */
        HDassert((size_t)(p - buf) == size);
	if(H5F_block_write(f, H5FD_MEM_FHEAP_HDR, addr, size, dxpl_id, buf) < 0)
	    HGOTO_ERROR(H5E_HEAP, H5E_CANTFLUSH, FAIL, "unable to save fractal heap header to disk")

	hdr->cache_info.is_dirty = FALSE;
    } /* end if */

    if(destroy)
        if(H5HF_cache_hdr_dest(f, hdr) < 0)
	    HGOTO_ERROR(H5E_HEAP, H5E_CANTFREE, FAIL, "unable to destroy fractal heap header")

done:
    /* Release resources */
    if(wb && H5WB_unwrap(wb) < 0)
        HDONE_ERROR(H5E_HEAP, H5E_CLOSEERROR, FAIL, "can't close wrapped buffer")

    FUNC_LEAVE_NOAPI(ret_value)
} /* H5HF_cache_hdr_flush() */


/*-------------------------------------------------------------------------
 * Function:	H5HF_cache_hdr_dest
 *
 * Purpose:	Destroys a fractal heap header in memory.
 *
 * Return:	Non-negative on success/Negative on failure
 *
 * Programmer:	Quincey Koziol
 *		koziol@ncsa.uiuc.edu
 *		Feb 24 2006
 *
 *-------------------------------------------------------------------------
 */
static herr_t
H5HF_cache_hdr_dest(H5F_t *f, H5HF_hdr_t *hdr)
{
    herr_t      ret_value = SUCCEED;    /* Return value */

    FUNC_ENTER_NOAPI_NOINIT(H5HF_cache_hdr_dest)

    /*
     * Check arguments.
     */
    HDassert(hdr);
    HDassert(hdr->rc == 0);

    /* If we're going to free the space on disk, the address must be valid */
    HDassert(!hdr->cache_info.free_file_space_on_destroy || H5F_addr_defined(hdr->cache_info.addr));

    /* Check for freeing file space for heap header */
    if(hdr->cache_info.free_file_space_on_destroy) {
        /* Release the space on disk */
        /* (XXX: Nasty usage of internal DXPL value! -QAK) */
        if(H5MF_xfree(f, H5FD_MEM_FHEAP_HDR, H5AC_dxpl_id, hdr->cache_info.addr, (hsize_t)hdr->heap_size) < 0)
            HGOTO_ERROR(H5E_HEAP, H5E_CANTFREE, FAIL, "unable to free fractal heap header")
    } /* end if */

    /* Free the shared info itself */
    if(H5HF_hdr_free(hdr) < 0)
        HGOTO_ERROR(H5E_HEAP, H5E_CANTRELEASE, FAIL, "unable to release fractal heap header")

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5HF_cache_hdr_dest() */


/*-------------------------------------------------------------------------
 * Function:	H5HF_cache_hdr_clear
 *
 * Purpose:	Mark a fractal heap header in memory as non-dirty.
 *
 * Return:	Non-negative on success/Negative on failure
 *
 * Programmer:	Quincey Koziol
 *		koziol@ncsa.uiuc.edu
 *		Feb 24 2006
 *
 *-------------------------------------------------------------------------
 */
static herr_t
H5HF_cache_hdr_clear(H5F_t *f, H5HF_hdr_t *hdr, hbool_t destroy)
{
    herr_t ret_value = SUCCEED;         /* Return value */

    FUNC_ENTER_NOAPI_NOINIT(H5HF_cache_hdr_clear)

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

    /* Reset the dirty flag.  */
    hdr->cache_info.is_dirty = FALSE;

    if(destroy)
        if(H5HF_cache_hdr_dest(f, hdr) < 0)
	    HGOTO_ERROR(H5E_HEAP, H5E_CANTFREE, FAIL, "unable to destroy fractal heap header")

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5HF_cache_hdr_clear() */


/*-------------------------------------------------------------------------
 * Function:	H5HF_cache_hdr_size
 *
 * Purpose:	Compute the size in bytes of a fractal heap header
 *		on disk, and return it in *size_ptr.  On failure,
 *		the value of *size_ptr is undefined.
 *
 * Return:	Non-negative on success/Negative on failure
 *
 * Programmer:	Quincey Koziol
 *		koziol@ncsa.uiuc.edu
 *		Feb 24 2006
 *
 *-------------------------------------------------------------------------
 */
static herr_t
H5HF_cache_hdr_size(const H5F_t UNUSED *f, const H5HF_hdr_t *hdr, size_t *size_ptr)
{
    FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5HF_cache_hdr_size)

    /* Check arguments */
    HDassert(f);
    HDassert(hdr);
    HDassert(size_ptr);

    /* Set size value */
    *size_ptr = hdr->heap_size;

    FUNC_LEAVE_NOAPI(SUCCEED)
} /* H5HF_cache_hdr_size() */


/*-------------------------------------------------------------------------
 * Function:	H5HF_cache_iblock_load
 *
 * Purpose:	Loads a fractal heap indirect block from the disk.
 *
 * Return:	Success:	Pointer to a new fractal heap indirect block
 *
 *		Failure:	NULL
 *
 * Programmer:	Quincey Koziol
 *		koziol@ncsa.uiuc.edu
 *		Feb 27 2006
 *
 *-------------------------------------------------------------------------
 */
static H5HF_indirect_t *
H5HF_cache_iblock_load(H5F_t *f, hid_t dxpl_id, haddr_t addr, void *_udata)
{
    H5HF_hdr_t          *hdr;           /* Shared fractal heap information */
    H5HF_iblock_cache_ud_t *udata = (H5HF_iblock_cache_ud_t *)_udata; /* user data for callback */
    H5HF_indirect_t	*iblock = NULL; /* Indirect block info */
    H5WB_t              *wb = NULL;     /* Wrapped buffer for indirect block data */
    uint8_t             iblock_buf[H5HF_IBLOCK_BUF_SIZE]; /* Buffer for indirect block */
    uint8_t		*buf;           /* Temporary buffer */
    const uint8_t	*p;             /* Pointer into raw data buffer */
    haddr_t             heap_addr;      /* Address of heap header in the file */
    uint32_t            stored_chksum;  /* Stored metadata checksum value */
    uint32_t            computed_chksum; /* Computed metadata checksum value */
    unsigned            u;              /* Local index variable */
    H5HF_indirect_t	*ret_value;     /* Return value */

    FUNC_ENTER_NOAPI_NOINIT(H5HF_cache_iblock_load)

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

    /* Allocate space for the fractal heap indirect block */
    if(NULL == (iblock = H5FL_CALLOC(H5HF_indirect_t)))
	HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL, "memory allocation failed")

    /* Get the pointer to the shared heap header */
    hdr = udata->par_info->hdr;

    /* Set the shared heap header's file context for this operation */
    hdr->f = udata->f;

    /* Share common heap information */
    iblock->hdr = hdr;
    if(H5HF_hdr_incr(hdr) < 0)
	HGOTO_ERROR(H5E_HEAP, H5E_CANTINC, NULL, "can't increment reference count on shared heap header")

    /* Set block's internal information */
    iblock->rc = 0;
    iblock->nrows = *udata->nrows;
    iblock->nchildren = 0;

    /* Wrap the local buffer for serialized indirect block */
    if(NULL == (wb = H5WB_wrap(iblock_buf, sizeof(iblock_buf))))
        HGOTO_ERROR(H5E_HEAP, H5E_CANTINIT, NULL, "can't wrap buffer")

    /* Compute size of indirect block */
    iblock->size = H5HF_MAN_INDIRECT_SIZE(hdr, iblock->nrows);

    /* Get a pointer to a buffer that's large enough for serialized indirect block */
    if(NULL == (buf = (uint8_t *)H5WB_actual(wb, iblock->size)))
        HGOTO_ERROR(H5E_HEAP, H5E_NOSPACE, NULL, "can't get actual buffer")

    /* Read indirect block from disk */
    if(H5F_block_read(f, H5FD_MEM_FHEAP_IBLOCK, addr, iblock->size, dxpl_id, buf) < 0)
	HGOTO_ERROR(H5E_HEAP, H5E_READERROR, NULL, "can't read fractal heap indirect block")

    /* Get temporary pointer to serialized indirect block */
    p = buf;

    /* Magic number */
    if(HDmemcmp(p, H5HF_IBLOCK_MAGIC, (size_t)H5_SIZEOF_MAGIC))
	HGOTO_ERROR(H5E_HEAP, H5E_CANTLOAD, NULL, "wrong fractal heap indirect block signature")
    p += H5_SIZEOF_MAGIC;

    /* Version */
    if(*p++ != H5HF_IBLOCK_VERSION)
	HGOTO_ERROR(H5E_HEAP, H5E_VERSION, NULL, "wrong fractal heap direct block version")

    /* Address of heap that owns this block */
    H5F_addr_decode(udata->f, &p, &heap_addr);
    if(H5F_addr_ne(heap_addr, hdr->heap_addr))
	HGOTO_ERROR(H5E_HEAP, H5E_CANTLOAD, NULL, "incorrect heap header address for direct block")

    /* Address of parent block */
    iblock->parent = udata->par_info->iblock;
    iblock->par_entry = udata->par_info->entry;
    if(iblock->parent) {
        /* Share parent block */
        if(H5HF_iblock_incr(iblock->parent) < 0)
            HGOTO_ERROR(H5E_HEAP, H5E_CANTINC, NULL, "can't increment reference count on shared indirect block")

        /* Set max. # of rows in this block */
        iblock->max_rows = iblock->nrows;
    } /* end if */
    else {
        /* Set max. # of rows in this block */
        iblock->max_rows = hdr->man_dtable.max_root_rows;
    } /* end else */

    /* Offset of heap within the heap's address space */
    UINT64DECODE_VAR(p, iblock->block_off, hdr->heap_off_size);

    /* Allocate & decode child block entry tables */
    HDassert(iblock->nrows > 0);
    if(NULL == (iblock->ents = H5FL_SEQ_MALLOC(H5HF_indirect_ent_t, (size_t)(iblock->nrows * hdr->man_dtable.cparam.width))))
	HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL, "memory allocation failed for direct entries")
    if(hdr->filter_len > 0) {
        unsigned dir_rows;      /* Number of direct rows in this indirect block */

        /* Compute the number of direct rows for this indirect block */
        dir_rows = MIN(iblock->nrows, hdr->man_dtable.max_direct_rows);

        /* Allocate indirect block filtered entry array */
        if(NULL == (iblock->filt_ents = H5FL_SEQ_MALLOC(H5HF_indirect_filt_ent_t, (size_t)(dir_rows * hdr->man_dtable.cparam.width))))
            HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL, "memory allocation failed for block entries")
    } /* end if */
    else
        iblock->filt_ents = NULL;
    for(u = 0; u < (iblock->nrows * hdr->man_dtable.cparam.width); u++) {
        /* Decode child block address */
        H5F_addr_decode(udata->f, &p, &(iblock->ents[u].addr));

        /* Check for heap with I/O filters */
        if(hdr->filter_len > 0) {
            /* Sanity check */
            HDassert(iblock->filt_ents);

            /* Decode extra information for direct blocks */
            if(u < (hdr->man_dtable.max_direct_rows * hdr->man_dtable.cparam.width)) {
                /* Size of filtered direct block */
                H5F_DECODE_LENGTH(udata->f, p, iblock->filt_ents[u].size);

                /* Sanity check */
                /* (either both the address & size are defined or both are
                 *  not defined)
                 */
                HDassert((H5F_addr_defined(iblock->ents[u].addr) && iblock->filt_ents[u].size)
                    || (!H5F_addr_defined(iblock->ents[u].addr) && iblock->filt_ents[u].size == 0));

                /* I/O filter mask for filtered direct block */
                UINT32DECODE(p, iblock->filt_ents[u].filter_mask);
            } /* end if */
        } /* end if */

        /* Count child blocks */
        if(H5F_addr_defined(iblock->ents[u].addr)) {
            iblock->nchildren++;
            iblock->max_child = u;
        } /* end if */
    } /* end for */

    /* Sanity check */
    HDassert(iblock->nchildren);        /* indirect blocks w/no children should have been deleted */

    /* Compute checksum on indirect block */
    computed_chksum = H5_checksum_metadata(buf, (size_t)(p - (const uint8_t *)buf), 0);

    /* Metadata checksum */
    UINT32DECODE(p, stored_chksum);

    /* Sanity check */
    HDassert((size_t)(p - (const uint8_t *)buf) == iblock->size);

    /* Verify checksum */
    if(stored_chksum != computed_chksum)
	HGOTO_ERROR(H5E_HEAP, H5E_BADVALUE, NULL, "incorrect metadata checksum for fractal heap indirect block")

    /* Check if we have any indirect block children */
    if(iblock->nrows > hdr->man_dtable.max_direct_rows) {
        unsigned indir_rows;      /* Number of indirect rows in this indirect block */

        /* Compute the number of indirect rows for this indirect block */
        indir_rows = iblock->nrows - hdr->man_dtable.max_direct_rows;

        /* Allocate & initialize child indirect block pointer array */
        if(NULL == (iblock->child_iblocks = H5FL_SEQ_CALLOC(H5HF_indirect_ptr_t, (size_t)(indir_rows * hdr->man_dtable.cparam.width))))
            HGOTO_ERROR(H5E_HEAP, H5E_NOSPACE, NULL, "memory allocation failed for block entries")
    } /* end if */
    else
        iblock->child_iblocks = NULL;

    /* Set return value */
    ret_value = iblock;

done:
    /* Release resources */
    if(wb && H5WB_unwrap(wb) < 0)
        HDONE_ERROR(H5E_HEAP, H5E_CLOSEERROR, NULL, "can't close wrapped buffer")
    if(!ret_value && iblock)
        if(H5HF_man_iblock_dest(iblock) < 0)
            HDONE_ERROR(H5E_HEAP, H5E_CANTFREE, NULL, "unable to destroy fractal heap indirect block")

    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5HF_cache_iblock_load() */


/*-------------------------------------------------------------------------
 * Function:	H5HF_cache_iblock_flush
 *
 * Purpose:	Flushes a dirty fractal heap indirect block to disk.
 *
 * Return:	Non-negative on success/Negative on failure
 *
 * Programmer:	Quincey Koziol
 *		koziol@ncsa.uiuc.edu
 *		Mar  6 2006
 *
 *-------------------------------------------------------------------------
 */
static herr_t
H5HF_cache_iblock_flush(H5F_t *f, hid_t dxpl_id, hbool_t destroy, haddr_t addr, H5HF_indirect_t *iblock, unsigned UNUSED * flags_ptr)
{
    H5WB_t      *wb = NULL;             /* Wrapped buffer for indirect block data */
    uint8_t     iblock_buf[H5HF_IBLOCK_BUF_SIZE]; /* Buffer for indirect block */
    herr_t      ret_value = SUCCEED;    /* Return value */

    FUNC_ENTER_NOAPI_NOINIT(H5HF_cache_iblock_flush)

    /* check arguments */
    HDassert(f);
    HDassert(H5F_addr_defined(addr));
    HDassert(iblock);

    if(iblock->cache_info.is_dirty) {
        H5HF_hdr_t *hdr;                /* Shared fractal heap information */
        uint8_t	*buf;                   /* Temporary buffer */
        uint8_t *p;                     /* Pointer into raw data buffer */
#ifndef NDEBUG
        unsigned nchildren = 0;         /* Track # of children */
        unsigned max_child = 0;         /* Track max. child entry used */
#endif /* NDEBUG */
        uint32_t metadata_chksum;       /* Computed metadata checksum value */
        size_t u;                       /* Local index variable */

        /* Get the pointer to the shared heap header */
        hdr = iblock->hdr;

        /* Set the shared heap header's file context for this operation */
        hdr->f = f;

        /* Wrap the local buffer for serialized indirect block */
        if(NULL == (wb = H5WB_wrap(iblock_buf, sizeof(iblock_buf))))
            HGOTO_ERROR(H5E_HEAP, H5E_CANTINIT, FAIL, "can't wrap buffer")

        /* Get a pointer to a buffer that's large enough for serialized indirect block */
        if(NULL == (buf = (uint8_t *)H5WB_actual(wb, iblock->size)))
            HGOTO_ERROR(H5E_HEAP, H5E_NOSPACE, FAIL, "can't get actual buffer")

        /* Get temporary pointer to buffer for serialized indirect block */
        p = buf;

        /* Magic number */
        HDmemcpy(p, H5HF_IBLOCK_MAGIC, (size_t)H5_SIZEOF_MAGIC);
        p += H5_SIZEOF_MAGIC;

        /* Version # */
        *p++ = H5HF_IBLOCK_VERSION;

        /* Address of heap header for heap which owns this block */
        H5F_addr_encode(f, &p, hdr->heap_addr);

        /* Offset of block in heap */
        UINT64ENCODE_VAR(p, iblock->block_off, hdr->heap_off_size);

        /* Encode indirect block-specific fields */
        for(u = 0; u < (iblock->nrows * hdr->man_dtable.cparam.width); u++) {
            /* Encode child block address */
            H5F_addr_encode(f, &p, iblock->ents[u].addr);

            /* Check for heap with I/O filters */
            if(hdr->filter_len > 0) {
                /* Sanity check */
                HDassert(iblock->filt_ents);

                /* Encode extra information for direct blocks */
                if(u < (hdr->man_dtable.max_direct_rows * hdr->man_dtable.cparam.width)) {
                    /* Sanity check */
                    /* (either both the address & size are defined or both are
                     *  not defined)
                     */
                    HDassert((H5F_addr_defined(iblock->ents[u].addr) && iblock->filt_ents[u].size)
                        || (!H5F_addr_defined(iblock->ents[u].addr) && iblock->filt_ents[u].size == 0));

                    /* Size of filtered direct block */
                    H5F_ENCODE_LENGTH(f, p, iblock->filt_ents[u].size);

                    /* I/O filter mask for filtered direct block */
                    UINT32ENCODE(p, iblock->filt_ents[u].filter_mask);
                } /* end if */
            } /* end if */

#ifndef NDEBUG
            /* Count child blocks */
            if(H5F_addr_defined(iblock->ents[u].addr)) {
                nchildren++;
                if(u > max_child)
                    max_child = u;
            } /* end if */
#endif /* NDEBUG */
        } /* end for */

        /* Compute checksum */
        metadata_chksum = H5_checksum_metadata(buf, (size_t)(p - buf), 0);

        /* Metadata checksum */
        UINT32ENCODE(p, metadata_chksum);

        /* Sanity check */
        HDassert((size_t)(p - buf) == iblock->size);
#ifndef NDEBUG
        HDassert(nchildren == iblock->nchildren);
        HDassert(max_child == iblock->max_child);
#endif /* NDEBUG */

        /* Check for needing to re-allocate indirect block from 'temp.' to 'normal' file space */
        if(H5F_IS_TMP_ADDR(f, addr)) {
            /* Sanity check */
            HDassert(H5F_addr_eq(iblock->addr, addr));

            /* Allocate 'normal' space for the new indirect block on disk */
            if(HADDR_UNDEF == (addr = H5MF_alloc(f, H5FD_MEM_FHEAP_IBLOCK, dxpl_id, (hsize_t)iblock->size)))
                HGOTO_ERROR(H5E_HEAP, H5E_NOSPACE, FAIL, "file allocation failed for fractal heap indirect block")

            /* Sanity check */
            HDassert(!H5F_addr_eq(iblock->addr, addr));

            /* Let the metadata cache know the block moved */
            if(H5AC_move_entry(f, H5AC_FHEAP_IBLOCK, iblock->addr, addr) < 0)
                HGOTO_ERROR(H5E_HEAP, H5E_CANTMOVE, FAIL, "unable to move indirect block")

            /* Update the internal address for the block */
            iblock->addr = addr;

            /* Check for root indirect block */
            if(NULL == iblock->parent) {
                /* Update information about indirect block's location */
                hdr->man_dtable.table_addr = addr;

                /* Mark that heap header was modified */
                if(H5HF_hdr_dirty(hdr) < 0)
                    HGOTO_ERROR(H5E_HEAP, H5E_CANTDIRTY, FAIL, "can't mark heap header as dirty")
            } /* end if */
            else {
                H5HF_indirect_t *par_iblock;    /* Parent indirect block */
                unsigned par_entry;             /* Entry in parent indirect block */

                /* Get parent information */
                par_iblock = iblock->parent;
                par_entry = iblock->par_entry;

                /* Update information about indirect block's location */
                par_iblock->ents[par_entry].addr = addr;

                /* Mark that parent was modified */
                if(H5HF_iblock_dirty(par_iblock) < 0)
                    HGOTO_ERROR(H5E_HEAP, H5E_CANTDIRTY, FAIL, "can't mark heap header as dirty")
            } /* end if */
        } /* end if */

        /* Indirect block must be in 'normal' file space now */
        HDassert(!H5F_IS_TMP_ADDR(f, addr));

	/* Write the indirect block */
	if(H5F_block_write(f, H5FD_MEM_FHEAP_IBLOCK, addr, iblock->size, dxpl_id, buf) < 0)
	    HGOTO_ERROR(H5E_HEAP, H5E_CANTFLUSH, FAIL, "unable to save fractal heap indirect block to disk")

        /* Reset dirty flags */
	iblock->cache_info.is_dirty = FALSE;
    } /* end if */

    if(destroy)
        if(H5HF_cache_iblock_dest(f, iblock) < 0)
	    HGOTO_ERROR(H5E_HEAP, H5E_CANTFREE, FAIL, "unable to destroy fractal heap indirect block")

done:
    /* Release resources */
    if(wb && H5WB_unwrap(wb) < 0)
        HDONE_ERROR(H5E_HEAP, H5E_CLOSEERROR, FAIL, "can't close wrapped buffer")

    FUNC_LEAVE_NOAPI(ret_value)
} /* H5HF_cache_iblock_flush() */


/*-------------------------------------------------------------------------
 * Function:	H5HF_cache_iblock_dest
 *
 * Purpose:	Destroys a fractal heap indirect block in memory.
 *
 * Return:	Non-negative on success/Negative on failure
 *
 * Programmer:	Quincey Koziol
 *		koziol@ncsa.uiuc.edu
 *		Mar  6 2006
 *
 *-------------------------------------------------------------------------
 */
static herr_t
H5HF_cache_iblock_dest(H5F_t *f, H5HF_indirect_t *iblock)
{
    herr_t      ret_value = SUCCEED;    /* Return value */

    FUNC_ENTER_NOAPI_NOINIT(H5HF_cache_iblock_dest)

    /*
     * Check arguments.
     */
    HDassert(iblock);
    HDassert(iblock->rc == 0);
    HDassert(iblock->hdr);

    /* If we're going to free the space on disk, the address must be valid */
    HDassert(!iblock->cache_info.free_file_space_on_destroy || H5F_addr_defined(iblock->cache_info.addr));

    /* Check for freeing file space for indirect block */
    if(iblock->cache_info.free_file_space_on_destroy) {
        /* Check if the indirect block is NOT currently allocated in temp. file space */
        /* (temp. file space does not need to be freed) */
        if(!H5F_IS_TMP_ADDR(f, iblock->cache_info.addr)) {
            /* Release the space on disk */
            /* (XXX: Nasty usage of internal DXPL value! -QAK) */
            if(H5MF_xfree(f, H5FD_MEM_FHEAP_IBLOCK, H5AC_dxpl_id, iblock->cache_info.addr, (hsize_t)iblock->size) < 0)
                HGOTO_ERROR(H5E_HEAP, H5E_CANTFREE, FAIL, "unable to free fractal heap indirect block")
        } /* end if */
    } /* end if */

    /* Destroy fractal heap indirect block */
    if(H5HF_man_iblock_dest(iblock) < 0)
        HGOTO_ERROR(H5E_HEAP, H5E_CANTFREE, FAIL, "unable to destroy fractal heap indirect block")

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5HF_cache_iblock_dest() */


/*-------------------------------------------------------------------------
 * Function:	H5HF_cache_iblock_clear
 *
 * Purpose:	Mark a fractal heap indirect block in memory as non-dirty.
 *
 * Return:	Non-negative on success/Negative on failure
 *
 * Programmer:	Quincey Koziol
 *		koziol@ncsa.uiuc.edu
 *		Mar  6 2006
 *
 *-------------------------------------------------------------------------
 */
static herr_t
H5HF_cache_iblock_clear(H5F_t *f, H5HF_indirect_t *iblock, hbool_t destroy)
{
    herr_t ret_value = SUCCEED;         /* Return value */

    FUNC_ENTER_NOAPI_NOINIT(H5HF_cache_iblock_clear)

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

    /* Reset the dirty flag.  */
    iblock->cache_info.is_dirty = FALSE;

    if(destroy)
        if(H5HF_cache_iblock_dest(f, iblock) < 0)
	    HGOTO_ERROR(H5E_HEAP, H5E_CANTFREE, FAIL, "unable to destroy fractal heap indirect block")

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5HF_cache_iblock_clear() */


/*-------------------------------------------------------------------------
 * Function:	H5HF_cache_iblock_size
 *
 * Purpose:	Compute the size in bytes of a fractal heap indirect block
 *		on disk, and return it in *size_ptr.  On failure,
 *		the value of *size_ptr is undefined.
 *
 * Return:	Non-negative on success/Negative on failure
 *
 * Programmer:	Quincey Koziol
 *		koziol@ncsa.uiuc.edu
 *		Mar  6 2006
 *
 *-------------------------------------------------------------------------
 */
static herr_t
H5HF_cache_iblock_size(const H5F_t UNUSED *f, const H5HF_indirect_t *iblock, size_t *size_ptr)
{
    FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5HF_cache_iblock_size)

    /* Check arguments */
    HDassert(iblock);
    HDassert(size_ptr);

    /* Set size value */
    *size_ptr = iblock->size;

    FUNC_LEAVE_NOAPI(SUCCEED)
} /* H5HF_cache_iblock_size() */


/*-------------------------------------------------------------------------
 * Function:	H5HF_cache_dblock_load
 *
 * Purpose:	Loads a fractal heap direct block from the disk.
 *
 * Return:	Success:	Pointer to a new fractal heap direct block
 *
 *		Failure:	NULL
 *
 * Programmer:	Quincey Koziol
 *		koziol@ncsa.uiuc.edu
 *		Feb 27 2006
 *
 *-------------------------------------------------------------------------
 */
static H5HF_direct_t *
H5HF_cache_dblock_load(H5F_t *f, hid_t dxpl_id, haddr_t addr, void *_udata)
{
    H5HF_dblock_cache_ud_t *udata = (H5HF_dblock_cache_ud_t *)_udata; /* pointer to user data */
    H5HF_hdr_t          *hdr;           /* Shared fractal heap information */
    H5HF_parent_t       *par_info;      /* Pointer to parent information */
    H5HF_direct_t	*dblock = NULL; /* Direct block info */
    const uint8_t	*p;             /* Pointer into raw data buffer */
    haddr_t             heap_addr;      /* Address of heap header in the file */
    H5HF_direct_t	*ret_value;     /* Return value */

    FUNC_ENTER_NOAPI_NOINIT(H5HF_cache_dblock_load)

    /* Check arguments */
    HDassert(f);
    HDassert(H5F_addr_defined(addr));
    HDassert(udata != NULL);
    HDassert(udata->f != NULL);
    HDassert(udata->dblock_size > 0);

    /* Allocate space for the fractal heap direct block */
    if(NULL == (dblock = H5FL_MALLOC(H5HF_direct_t)))
	HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL, "memory allocation failed")
    HDmemset(&dblock->cache_info, 0, sizeof(H5AC_info_t));

    /* Get the pointer to the shared heap header */
    par_info = (H5HF_parent_t *)(&(udata->par_info));
    hdr = par_info->hdr;

    /* Set the shared heap header's file context for this operation */
    hdr->f = udata->f;

    /* Share common heap information */
    dblock->hdr = hdr;
    if(H5HF_hdr_incr(hdr) < 0)
	HGOTO_ERROR(H5E_HEAP, H5E_CANTINC, NULL, "can't increment reference count on shared heap header")

    /* Set block's internal information */
    dblock->size = udata->dblock_size;
    dblock->file_size = 0;

    /* Allocate block buffer */
/* XXX: Change to using free-list factories */
    if(NULL == (dblock->blk = H5FL_BLK_MALLOC(direct_block, (size_t)dblock->size)))
        HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL, "memory allocation failed")

    /* Check for I/O filters on this heap */
    if(hdr->filter_len > 0) {
        H5Z_cb_t filter_cb = {NULL, NULL};  /* Filter callback structure */
        size_t nbytes;          /* Number of bytes used in buffer, after applying reverse filters */
        void *read_buf;         /* Pointer to buffer to read in */
        size_t read_size;       /* Size of filtered direct block to read */
        unsigned filter_mask;	/* Excluded filters for direct block */

        /* Check for root direct block */
        if(par_info->iblock == NULL) {
            /* Sanity check */
            HDassert(H5F_addr_eq(hdr->man_dtable.table_addr, addr));

            /* Set up parameters to read filtered direct block */
            read_size = hdr->pline_root_direct_size;
        } /* end if */
        else {
            /* Sanity check */
            HDassert(H5F_addr_eq(par_info->iblock->ents[par_info->entry].addr, addr));

            /* Set up parameters to read filtered direct block */
            read_size = par_info->iblock->filt_ents[par_info->entry].size;
        } /* end else */

        /* Allocate buffer to perform I/O filtering on */
        if(NULL == (read_buf = H5MM_malloc(read_size)))
            HGOTO_ERROR(H5E_HEAP, H5E_NOSPACE, NULL, "memory allocation failed for pipeline buffer")

        /* Read filtered direct block from disk */
        if(H5F_block_read(f, H5FD_MEM_FHEAP_DBLOCK, addr, read_size, dxpl_id, read_buf) < 0)
            HGOTO_ERROR(H5E_HEAP, H5E_READERROR, NULL, "can't read fractal heap direct block")

        /* Push direct block data through I/O filter pipeline */
        nbytes = read_size;
        filter_mask = udata->filter_mask;
        if(H5Z_pipeline(&(hdr->pline), H5Z_FLAG_REVERSE, &filter_mask, H5Z_ENABLE_EDC, filter_cb, &nbytes, &read_size, &read_buf) < 0)
            HGOTO_ERROR(H5E_HEAP, H5E_CANTFILTER, NULL, "output pipeline failed")

        /* Sanity check */
        HDassert(nbytes == dblock->size);

        /* Copy un-filtered data into block's buffer */
        HDmemcpy(dblock->blk, read_buf, dblock->size);

        /* Release the read buffer */
        H5MM_xfree(read_buf);
    } /* end if */
    else {
        /* Read direct block from disk */
        if(H5F_block_read(f, H5FD_MEM_FHEAP_DBLOCK, addr, dblock->size, dxpl_id, dblock->blk) < 0)
            HGOTO_ERROR(H5E_HEAP, H5E_READERROR, NULL, "can't read fractal heap direct block")
    } /* end else */

    /* Start decoding direct block */
    p = dblock->blk;

    /* Magic number */
    if(HDmemcmp(p, H5HF_DBLOCK_MAGIC, (size_t)H5_SIZEOF_MAGIC))
	HGOTO_ERROR(H5E_HEAP, H5E_CANTLOAD, NULL, "wrong fractal heap direct block signature")
    p += H5_SIZEOF_MAGIC;

    /* Version */
    if(*p++ != H5HF_DBLOCK_VERSION)
	HGOTO_ERROR(H5E_HEAP, H5E_VERSION, NULL, "wrong fractal heap direct block version")

    /* Address of heap that owns this block (just for file integrity checks) */
    H5F_addr_decode(udata->f, &p, &heap_addr);
    if(H5F_addr_ne(heap_addr, hdr->heap_addr))
	HGOTO_ERROR(H5E_HEAP, H5E_CANTLOAD, NULL, "incorrect heap header address for direct block")

    /* Address of parent block */
    dblock->parent = par_info->iblock;
    dblock->par_entry = par_info->entry;
    if(dblock->parent) {
        /* Share parent block */
        if(H5HF_iblock_incr(dblock->parent) < 0)
            HGOTO_ERROR(H5E_HEAP, H5E_CANTINC, NULL, "can't increment reference count on shared indirect block")
    } /* end if */

    /* Offset of heap within the heap's address space */
    UINT64DECODE_VAR(p, dblock->block_off, hdr->heap_off_size);

    /* Decode checksum on direct block, if requested */
    if(hdr->checksum_dblocks) {
        uint32_t stored_chksum;         /* Metadata checksum value */
        uint32_t computed_chksum;       /* Computed metadata checksum value */

        /* Metadata checksum */
        UINT32DECODE(p, stored_chksum);

        /* Reset checksum field, for computing the checksum */
        /* (Casting away const OK - QAK) */
        HDmemset((uint8_t *)p - H5HF_SIZEOF_CHKSUM, 0, (size_t)H5HF_SIZEOF_CHKSUM);

        /* Compute checksum on entire direct block */
        computed_chksum = H5_checksum_metadata(dblock->blk, dblock->size, 0);

        /* Verify checksum */
        if(stored_chksum != computed_chksum)
            HGOTO_ERROR(H5E_HEAP, H5E_BADVALUE, NULL, "incorrect metadata checksum for fractal heap direct block")
    } /* end if */

    /* Sanity check */
    HDassert((size_t)(p - dblock->blk) == (size_t)H5HF_MAN_ABS_DIRECT_OVERHEAD(hdr));

    /* Set return value */
    ret_value = dblock;

done:
    if(!ret_value && dblock)
        if(H5HF_man_dblock_dest(dblock) < 0)
            HDONE_ERROR(H5E_HEAP, H5E_CANTFREE, NULL, "unable to destroy fractal heap direct block")

    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5HF_cache_dblock_load() */


/*-------------------------------------------------------------------------
 * Function:	H5HF_cache_dblock_flush
 *
 * Purpose:	Flushes a dirty fractal heap direct block to disk.
 *
 * Return:	Non-negative on success/Negative on failure
 *
 * Programmer:	Quincey Koziol
 *		koziol@ncsa.uiuc.edu
 *		Feb 27 2006
 *
 *-------------------------------------------------------------------------
 */
static herr_t
H5HF_cache_dblock_flush(H5F_t *f, hid_t dxpl_id, hbool_t destroy, haddr_t addr, H5HF_direct_t *dblock, unsigned UNUSED * flags_ptr)
{
    herr_t      ret_value = SUCCEED;    /* Return value */

    FUNC_ENTER_NOAPI_NOINIT(H5HF_cache_dblock_flush)

    /* check arguments */
    HDassert(f);
    HDassert(H5F_addr_defined(addr));
    HDassert(dblock);

    if(dblock->cache_info.is_dirty) {
        H5HF_hdr_t *hdr;        /* Shared fractal heap information */
        hbool_t at_tmp_addr = H5F_IS_TMP_ADDR(f, addr);     /* Flag to indicate direct block is at temporary address */
        void *write_buf;        /* Pointer to buffer to write out */
        size_t write_size;      /* Size of buffer to write out */
        uint8_t *p;             /* Pointer into raw data buffer */

        /* Get the pointer to the shared heap header */
        hdr = dblock->hdr;

        /* Set the shared heap header's file context for this operation */
        hdr->f = f;

        HDassert(dblock->blk);
        p = dblock->blk;

        /* Magic number */
        HDmemcpy(p, H5HF_DBLOCK_MAGIC, (size_t)H5_SIZEOF_MAGIC);
        p += H5_SIZEOF_MAGIC;

        /* Version # */
        *p++ = H5HF_DBLOCK_VERSION;

        /* Address of heap header for heap which owns this block */
        H5F_addr_encode(f, &p, hdr->heap_addr);

        /* Offset of block in heap */
        UINT64ENCODE_VAR(p, dblock->block_off, hdr->heap_off_size);

        /* Metadata checksum */
        if(hdr->checksum_dblocks) {
            uint32_t metadata_chksum;       /* Computed metadata checksum value */

            /* Clear the checksum field, to compute the checksum */
            HDmemset(p, 0, (size_t)H5HF_SIZEOF_CHKSUM);

            /* Compute checksum on entire direct block */
            metadata_chksum = H5_checksum_metadata(dblock->blk, dblock->size, 0);

            /* Metadata checksum */
            UINT32ENCODE(p, metadata_chksum);
        } /* end if */

        /* Sanity check */
        HDassert((size_t)(p - dblock->blk) == (size_t)H5HF_MAN_ABS_DIRECT_OVERHEAD(hdr));

        /* Check for I/O filters on this heap */
        if(hdr->filter_len > 0) {
            H5Z_cb_t filter_cb = {NULL, NULL};  /* Filter callback structure */
            size_t nbytes;                      /* Number of bytes used */
            unsigned filter_mask = 0;           /* Filter mask for block */

            /* Allocate buffer to perform I/O filtering on */
            write_size = dblock->size;
            if(NULL == (write_buf = H5MM_malloc(write_size)))
                HGOTO_ERROR(H5E_HEAP, H5E_NOSPACE, FAIL, "memory allocation failed for pipeline buffer")
            HDmemcpy(write_buf, dblock->blk, write_size);

            /* Push direct block data through I/O filter pipeline */
            nbytes = write_size;
            if(H5Z_pipeline(&(hdr->pline), 0, &filter_mask, H5Z_ENABLE_EDC, filter_cb, &nbytes, &write_size, &write_buf) < 0)
                HGOTO_ERROR(H5E_HEAP, H5E_WRITEERROR, FAIL, "output pipeline failed")

            /* Use the compressed number of bytes as the size to write */
            write_size = nbytes;

            /* Check for root direct block */
            if(dblock->parent == NULL) {
                hbool_t hdr_changed = FALSE;    /* Whether the header information changed */

                /* Sanity check */
                HDassert(H5F_addr_eq(hdr->man_dtable.table_addr, addr));
                HDassert(hdr->pline_root_direct_size > 0);

                /* Check if the filter mask changed */
                if(hdr->pline_root_direct_filter_mask != filter_mask) {
                    hdr->pline_root_direct_filter_mask = filter_mask;
                    hdr_changed = TRUE;
                } /* end if */

                /* Check if we need to re-size the block on disk */
                if(hdr->pline_root_direct_size != write_size || at_tmp_addr) {
                    /* Check if the direct block is NOT currently allocated in temp. file space */
                    /* (temp. file space does not need to be freed) */
                    if(!at_tmp_addr) {
                        /* Release direct block's current disk space */
                        if(H5MF_xfree(f, H5FD_MEM_FHEAP_DBLOCK, dxpl_id, addr, (hsize_t)hdr->pline_root_direct_size) < 0)
                            HGOTO_ERROR(H5E_HEAP, H5E_CANTFREE, FAIL, "unable to free fractal heap direct block")
                    } /* end if */

                    /* Allocate space for the compressed direct block */
                    if(HADDR_UNDEF == (addr = H5MF_alloc(f, H5FD_MEM_FHEAP_DBLOCK, dxpl_id, (hsize_t)write_size)))
                        HGOTO_ERROR(H5E_HEAP, H5E_NOSPACE, FAIL, "file allocation failed for fractal heap direct block")

                    /* Let the metadata cache know, if the block moved */
                    if(!H5F_addr_eq(hdr->man_dtable.table_addr, addr))
                        if(H5AC_move_entry(f, H5AC_FHEAP_DBLOCK, hdr->man_dtable.table_addr, addr) < 0)
                            HGOTO_ERROR(H5E_HEAP, H5E_CANTMOVE, FAIL, "unable to move direct block")

                    /* Update information about compressed direct block's location & size */
                    hdr->man_dtable.table_addr = addr;
                    hdr->pline_root_direct_size = write_size;

                    /* Note that heap header was modified */
                    hdr_changed = TRUE;
                } /* end if */

                /* Check if heap header was modified */
                if(hdr_changed)
                    if(H5HF_hdr_dirty(hdr) < 0)
                        HGOTO_ERROR(H5E_HEAP, H5E_CANTDIRTY, FAIL, "can't mark heap header as dirty")
            } /* end if */
            else {
                hbool_t par_changed = FALSE;    /* Whether the parent's information changed */
                H5HF_indirect_t *par_iblock;    /* Parent indirect block */
                unsigned par_entry;             /* Entry in parent indirect block */

                /* Get parent information */
                par_iblock = dblock->parent;
                par_entry = dblock->par_entry;

                /* Sanity check */
                HDassert(H5F_addr_eq(par_iblock->ents[par_entry].addr, addr));
                HDassert(par_iblock->filt_ents[par_entry].size > 0);

                /* Check if the filter mask changed */
                if(par_iblock->filt_ents[par_entry].filter_mask != filter_mask) {
                    par_iblock->filt_ents[par_entry].filter_mask = filter_mask;
                    par_changed = TRUE;
                } /* end if */

                /* Check if we need to re-size the block on disk */
                if(par_iblock->filt_ents[par_entry].size != write_size || at_tmp_addr) {
                    /* Check if the direct block is NOT currently allocated in temp. file space */
                    /* (temp. file space does not need to be freed) */
                    if(!at_tmp_addr) {
                        /* Release direct block's current disk space */
                        if(H5MF_xfree(f, H5FD_MEM_FHEAP_DBLOCK, dxpl_id, addr, (hsize_t)par_iblock->filt_ents[par_entry].size) < 0)
                            HGOTO_ERROR(H5E_HEAP, H5E_CANTFREE, FAIL, "unable to free fractal heap direct block")
                    } /* end if */

                    /* Allocate space for the compressed direct block */
                    if(HADDR_UNDEF == (addr = H5MF_alloc(f, H5FD_MEM_FHEAP_DBLOCK, dxpl_id, (hsize_t)write_size)))
                        HGOTO_ERROR(H5E_HEAP, H5E_NOSPACE, FAIL, "file allocation failed for fractal heap direct block")

                    /* Let the metadata cache know, if the block moved */
                    if(!H5F_addr_eq(par_iblock->ents[par_entry].addr, addr))
                        if(H5AC_move_entry(f, H5AC_FHEAP_DBLOCK, par_iblock->ents[par_entry].addr, addr) < 0)
                            HGOTO_ERROR(H5E_HEAP, H5E_CANTMOVE, FAIL, "unable to move direct block")

                    /* Update information about compressed direct block's location & size */
                    par_iblock->ents[par_entry].addr = addr;
                    par_iblock->filt_ents[par_entry].size = write_size;

                    /* Note that parent was modified */
                    par_changed = TRUE;
                } /* end if */

                /* Check if parent was modified */
                if(par_changed)
                    if(H5HF_iblock_dirty(par_iblock) < 0)
                        HGOTO_ERROR(H5E_HEAP, H5E_CANTDIRTY, FAIL, "can't mark heap header as dirty")
            } /* end else */
        } /* end if */
        else {
            write_buf = dblock->blk;
            write_size = dblock->size;

            /* Check for needing to re-allocate direct block from 'temp.' to 'normal' file space */
            if(at_tmp_addr) {
                /* Check for root direct block */
                if(NULL == dblock->parent) {
                    /* Sanity check */
                    HDassert(H5F_addr_eq(hdr->man_dtable.table_addr, addr));

                    /* Allocate 'normal' space for the direct block */
                    if(HADDR_UNDEF == (addr = H5MF_alloc(f, H5FD_MEM_FHEAP_DBLOCK, dxpl_id, (hsize_t)write_size)))
                        HGOTO_ERROR(H5E_HEAP, H5E_NOSPACE, FAIL, "file allocation failed for fractal heap direct block")

                    /* Sanity check */
                    HDassert(!H5F_addr_eq(hdr->man_dtable.table_addr, addr));

                    /* Let the metadata cache know the block moved */
                    if(H5AC_move_entry(f, H5AC_FHEAP_DBLOCK, hdr->man_dtable.table_addr, addr) < 0)
                        HGOTO_ERROR(H5E_HEAP, H5E_CANTMOVE, FAIL, "unable to move direct block")

                    /* Update information about direct block's location */
                    hdr->man_dtable.table_addr = addr;

                    /* Mark that heap header was modified */
                    if(H5HF_hdr_dirty(hdr) < 0)
                        HGOTO_ERROR(H5E_HEAP, H5E_CANTDIRTY, FAIL, "can't mark heap header as dirty")
                } /* end if */
                else {
                    H5HF_indirect_t *par_iblock;    /* Parent indirect block */
                    unsigned par_entry;             /* Entry in parent indirect block */

                    /* Get parent information */
                    par_iblock = dblock->parent;
                    par_entry = dblock->par_entry;

                    /* Sanity check */
                    HDassert(H5F_addr_eq(par_iblock->ents[par_entry].addr, addr));

                    /* Allocate 'normal' space for the direct block */
                    if(HADDR_UNDEF == (addr = H5MF_alloc(f, H5FD_MEM_FHEAP_DBLOCK, dxpl_id, (hsize_t)write_size)))
                        HGOTO_ERROR(H5E_HEAP, H5E_NOSPACE, FAIL, "file allocation failed for fractal heap direct block")

                    /* Sanity check */
                    HDassert(!H5F_addr_eq(par_iblock->ents[par_entry].addr, addr));

                    /* Let the metadata cache know the block moved */
                    if(H5AC_move_entry(f, H5AC_FHEAP_DBLOCK, par_iblock->ents[par_entry].addr, addr) < 0)
                        HGOTO_ERROR(H5E_HEAP, H5E_CANTMOVE, FAIL, "unable to move direct block")

                    /* Update information about direct block's location */
                    par_iblock->ents[par_entry].addr = addr;

                    /* Mark that parent was modified */
                    if(H5HF_iblock_dirty(par_iblock) < 0)
                        HGOTO_ERROR(H5E_HEAP, H5E_CANTDIRTY, FAIL, "can't mark heap header as dirty")
                } /* end else */
            } /* end if */
        } /* end else */

        /* Direct block must be in 'normal' file space now */
        HDassert(!H5F_IS_TMP_ADDR(f, addr));

	/* Write the direct block */
	if(H5F_block_write(f, H5FD_MEM_FHEAP_DBLOCK, addr, write_size, dxpl_id, write_buf) < 0)
	    HGOTO_ERROR(H5E_HEAP, H5E_CANTFLUSH, FAIL, "unable to save fractal heap direct block to disk")

        /* Release the write buffer, if it was allocated */
        if(write_buf != dblock->blk)
            H5MM_xfree(write_buf);

	dblock->cache_info.is_dirty = FALSE;
    } /* end if */

    if(destroy)
        if(H5HF_cache_dblock_dest(f, dblock) < 0)
	    HGOTO_ERROR(H5E_HEAP, H5E_CANTFREE, FAIL, "unable to destroy fractal heap direct block")

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* H5HF_cache_dblock_flush() */


/*-------------------------------------------------------------------------
 * Function:	H5HF_cache_dblock_dest
 *
 * Purpose:	Destroys a fractal heap direct block in memory.
 *
 * Return:	Non-negative on success/Negative on failure
 *
 * Programmer:	Quincey Koziol
 *		koziol@ncsa.uiuc.edu
 *		Feb 27 2006
 *
 *-------------------------------------------------------------------------
 */
static herr_t
H5HF_cache_dblock_dest(H5F_t *f, H5HF_direct_t *dblock)
{
    herr_t      ret_value = SUCCEED;    /* Return value */

    FUNC_ENTER_NOAPI_NOINIT(H5HF_cache_dblock_dest)

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

    /* If we're going to free the space on disk, the address must be valid */
    HDassert(!dblock->cache_info.free_file_space_on_destroy || H5F_addr_defined(dblock->cache_info.addr));

    /* Check for freeing file space for direct block */
    if(dblock->cache_info.free_file_space_on_destroy) {
        /* Sanity check */
        HDassert(dblock->file_size > 0);

        /* Check if the direct block is NOT currently allocated in temp. file space */
        /* (temp. file space does not need to be freed) */
        if(!H5F_IS_TMP_ADDR(f, dblock->cache_info.addr)) {
            /* Release the space on disk */
            /* (XXX: Nasty usage of internal DXPL value! -QAK) */
            if(H5MF_xfree(f, H5FD_MEM_FHEAP_DBLOCK, H5AC_dxpl_id, dblock->cache_info.addr, dblock->file_size) < 0)
                HGOTO_ERROR(H5E_HEAP, H5E_CANTFREE, FAIL, "unable to free fractal heap direct block")
        } /* end if */
    } /* end if */

    /* Destroy fractal heap direct block */
    if(H5HF_man_dblock_dest(dblock) < 0)
        HGOTO_ERROR(H5E_HEAP, H5E_CANTFREE, FAIL, "unable to destroy fractal heap direct block")

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5HF_cache_dblock_dest() */


/*-------------------------------------------------------------------------
 * Function:	H5HF_cache_dblock_clear
 *
 * Purpose:	Mark a fractal heap direct block in memory as non-dirty.
 *
 * Return:	Non-negative on success/Negative on failure
 *
 * Programmer:	Quincey Koziol
 *		koziol@ncsa.uiuc.edu
 *		Feb 27 2006
 *
 *-------------------------------------------------------------------------
 */
static herr_t
H5HF_cache_dblock_clear(H5F_t *f, H5HF_direct_t *dblock, hbool_t destroy)
{
    herr_t ret_value = SUCCEED;         /* Return value */

    FUNC_ENTER_NOAPI_NOINIT(H5HF_cache_dblock_clear)

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

    /* Reset the dirty flag.  */
    dblock->cache_info.is_dirty = FALSE;

    if(destroy)
        if(H5HF_cache_dblock_dest(f, dblock) < 0)
	    HGOTO_ERROR(H5E_HEAP, H5E_CANTFREE, FAIL, "unable to destroy fractal heap direct block")

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5HF_cache_dblock_clear() */


/*-------------------------------------------------------------------------
 * Function:	H5HF_cache_dblock_size
 *
 * Purpose:	Compute the size in bytes of a fractal heap direct block
 *		on disk, and return it in *size_ptr.  On failure,
 *		the value of *size_ptr is undefined.
 *
 * Return:	Non-negative on success/Negative on failure
 *
 * Programmer:	Quincey Koziol
 *		koziol@ncsa.uiuc.edu
 *		Feb 24 2006
 *
 *-------------------------------------------------------------------------
 */
static herr_t
H5HF_cache_dblock_size(const H5F_t UNUSED *f, const H5HF_direct_t *dblock, size_t *size_ptr)
{
    FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5HF_cache_dblock_size)

    /* check arguments */
    HDassert(dblock);
    HDassert(size_ptr);

    /* Set size value */
    *size_ptr = dblock->size;

    FUNC_LEAVE_NOAPI(SUCCEED)
} /* H5HF_cache_dblock_size() */