summaryrefslogtreecommitdiffstats
path: root/src/H5HP.c
blob: d62bd4e661d35a651aa3262d8b3d1f9d2a6ecd3d (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
/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
 * 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://hdf.ncsa.uiuc.edu/HDF5/doc/Copyright.html.  If you do not have     *
 * access to either file, you may request a copy from hdfhelp@ncsa.uiuc.edu. *
 * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */

/*
 * Purpose:	Provides a heap abstract data type.
 *
 *              (See chapter 11 - "Priority Queues" of _Algorithms_, by
 *              Sedgewick for additional information)
 *
 */

/* Private headers needed */
#include "H5private.h"		/* Generic Functions			*/
#include "H5Eprivate.h"		/* Error handling		  	*/
#include "H5HPprivate.h"	/* Heap routines			*/
#include "H5FLprivate.h"	/* Memory management functions		*/

/* Pablo information */
#define PABLO_MASK	H5HP_mask

/* Interface initialization? */
static int		interface_initialize_g = 0;
#define INTERFACE_INIT NULL

/* Local Macros */
#define H5HP_START_SIZE 16      /* Initial number of entries for heaps */

/* Private typedefs & structs */

/* Data structure for entries in the internal heap array */
typedef struct {
    int val;            /* Value to be used for heap condition */
    H5HP_info_t *obj;   /* Pointer to object stored in heap */
}H5HP_ent_t;

/* Main heap data structure */
struct H5HP_t {
    H5HP_type_t type;   /* Type of heap (minimum or maximum value at "top") */
    size_t nobjs;       /* Number of active objects in heap array */
    size_t nalloc;      /* Number of allocated locations in heap array */
    H5HP_ent_t *heap;   /* Pointer to array containing heap entries */
};

/* Static functions */
static herr_t H5HP_swim_max(H5HP_t *heap, size_t loc);
static herr_t H5HP_swim_min(H5HP_t *heap, size_t loc);
static herr_t H5HP_sink_max(H5HP_t *heap, size_t loc);
static herr_t H5HP_sink_min(H5HP_t *heap, size_t loc);

/* Declare a free list to manage the H5HP_t struct */
H5FL_DEFINE_STATIC(H5HP_t);

/* Declare a free list to manage arrays of H5HP_ent_t */
H5FL_ARR_DEFINE_STATIC(H5HP_ent_t,-1);


/*--------------------------------------------------------------------------
 NAME
    H5HP_swim_max
 PURPOSE
    Restore heap condition by moving an object upward
 USAGE
    herr_t H5HP_swim_max(heap, loc)
        H5HP_t *heap;           IN/OUT: Pointer to heap to modify
        size_t loc;             IN: Location to start from

 RETURNS
    Returns non-negative on success, negative on failure.
 DESCRIPTION
    Restore the heap condition for the heap's array by "swimming" the object
    at a location upward.
 GLOBAL VARIABLES
 COMMENTS, BUGS, ASSUMPTIONS
    This routine is for "maximum" value heaps.
 EXAMPLES
 REVISION LOG
--------------------------------------------------------------------------*/
static herr_t
H5HP_swim_max(H5HP_t *heap, size_t loc)
{
    int val;                    /* Temporary copy value of object to move in heap */
    H5HP_info_t *obj;           /* Temporary pointer to object to move in heap */
    herr_t ret_value=SUCCEED;   /* Return value */

    FUNC_ENTER_NOINIT(H5HP_swim_max);

    /* Get copies of the information about the object to move in the heap */
    val=heap->heap[loc].val;
    obj=heap->heap[loc].obj;

    /* Move object up in heap until it's reached the maximum location possible */
    while(heap->heap[loc/2].val < val) {
        /* Move object "above" current location in heap down */
        heap->heap[loc].val=heap->heap[loc/2].val;
        heap->heap[loc].obj=heap->heap[loc/2].obj;

        /* Update heap location for object which moved */
        heap->heap[loc].obj->heap_loc=loc;

        /* Move to location "above" current location */
        loc=loc/2;
    } /* end while */

    /* Put object into heap at correct location */
    heap->heap[loc].val=val;
    heap->heap[loc].obj=obj;

    /* Update heap location for object */
    heap->heap[loc].obj->heap_loc=loc;

    FUNC_LEAVE_NOAPI(ret_value);
} /* end H5HP_swim_max() */


/*--------------------------------------------------------------------------
 NAME
    H5HP_swim_min
 PURPOSE
    Restore heap condition by moving an object upward
 USAGE
    herr_t H5HP_swim_min(heap, loc)
        H5HP_t *heap;           IN/OUT: Pointer to heap to modify
        size_t loc;             IN: Location to start from

 RETURNS
    Returns non-negative on success, negative on failure.
 DESCRIPTION
    Restore the heap condition for the heap's array by "swimming" the object
    at a location upward.
 GLOBAL VARIABLES
 COMMENTS, BUGS, ASSUMPTIONS
    This routine is for "minimum" value heaps.
 EXAMPLES
 REVISION LOG
--------------------------------------------------------------------------*/
static herr_t
H5HP_swim_min(H5HP_t *heap, size_t loc)
{
    int val;                    /* Temporary copy value of object to move in heap */
    H5HP_info_t *obj;           /* Temporary pointer to object to move in heap */
    herr_t ret_value=SUCCEED;   /* Return value */

    FUNC_ENTER_NOINIT(H5HP_swim_min);

    /* Get copies of the information about the object to move in the heap */
    val=heap->heap[loc].val;
    obj=heap->heap[loc].obj;

    /* Move object up in heap until it's reached the minimum location possible */
    while(heap->heap[loc/2].val > val) {
        /* Move object "above" current location in heap down */
        heap->heap[loc].val=heap->heap[loc/2].val;
        heap->heap[loc].obj=heap->heap[loc/2].obj;

        /* Update heap location for object which moved */
        heap->heap[loc].obj->heap_loc=loc;

        /* Move to location "above" current location */
        loc=loc/2;
    } /* end while */

    /* Put object into heap at correct location */
    heap->heap[loc].val=val;
    heap->heap[loc].obj=obj;

    /* Update heap location for object */
    heap->heap[loc].obj->heap_loc=loc;

    FUNC_LEAVE_NOAPI(ret_value);
} /* end H5HP_swim_min() */


/*--------------------------------------------------------------------------
 NAME
    H5HP_sink_max
 PURPOSE
    Restore heap condition by moving an object downward
 USAGE
    herr_t H5HP_sink_max(heap, loc)
        H5HP_t *heap;           IN/OUT: Pointer to heap to modify
        size_t loc;             IN: Location to start from

 RETURNS
    Returns non-negative on success, negative on failure.
 DESCRIPTION
    Restore the heap condition for the heap's array by "sinking" the object
    at a location downward.
 GLOBAL VARIABLES
 COMMENTS, BUGS, ASSUMPTIONS
    This routine is for "maximum" value heaps.
 EXAMPLES
 REVISION LOG
--------------------------------------------------------------------------*/
static herr_t
H5HP_sink_max(H5HP_t *heap, size_t loc)
{
    int val;                    /* Temporary copy value of object to move in heap */
    void *obj;                  /* Temporary pointer to object to move in heap */
    herr_t ret_value=SUCCEED;   /* Return value */

    FUNC_ENTER_NOINIT(H5HP_sink_max);

    /* Get copies of the information about the object to move in the heap */
    val=heap->heap[loc].val;
    obj=heap->heap[loc].obj;

    /* Move object up in heap until it's reached the maximum location possible */
    while((2*loc)<=heap->nobjs) {
        size_t new_loc=loc*2;   /* New object's potential location area */

        /* Get the greater of the two objects below the location in heap */
        if(new_loc<heap->nobjs && (heap->heap[new_loc].val < heap->heap[new_loc+1].val))
            new_loc++;

        /* Check if the object is smaller than the larger of the objects below it */
        /* If so, its in the correct location now, and we can get out */
        if(val >= heap->heap[new_loc].val)
            break;

        /* Move the greater of the two objects below the current location up */
        heap->heap[loc].val=heap->heap[new_loc].val;
        heap->heap[loc].obj=heap->heap[new_loc].obj;

        /* Update heap location for object which moved */
        heap->heap[loc].obj->heap_loc=loc;

        /* Move to location "below" current location */
        loc=new_loc;
    } /* end while */

    /* Put object into heap at correct location */
    heap->heap[loc].val=val;
    heap->heap[loc].obj=obj;

    /* Update heap location for object */
    heap->heap[loc].obj->heap_loc=loc;

    FUNC_LEAVE_NOAPI(ret_value);
} /* end H5HP_sink_max() */


/*--------------------------------------------------------------------------
 NAME
    H5HP_sink_min
 PURPOSE
    Restore heap condition by moving an object downward
 USAGE
    herr_t H5HP_sink_min(heap, loc)
        H5HP_t *heap;           IN/OUT: Pointer to heap to modify
        size_t loc;             IN: Location to start from

 RETURNS
    Returns non-negative on success, negative on failure.
 DESCRIPTION
    Restore the heap condition for the heap's array by "sinking" the object
    at a location downward.
 GLOBAL VARIABLES
 COMMENTS, BUGS, ASSUMPTIONS
    This routine is for "minimum" value heaps.
 EXAMPLES
 REVISION LOG
--------------------------------------------------------------------------*/
static herr_t
H5HP_sink_min(H5HP_t *heap, size_t loc)
{
    int val;                    /* Temporary copy value of object to move in heap */
    void *obj;                  /* Temporary pointer to object to move in heap */
    herr_t ret_value=SUCCEED;   /* Return value */

    FUNC_ENTER_NOINIT(H5HP_sink_min);

    /* Get copies of the information about the object to move in the heap */
    val=heap->heap[loc].val;
    obj=heap->heap[loc].obj;

    /* Move object up in heap until it's reached the maximum location possible */
    while((2*loc)<=heap->nobjs) {
        size_t new_loc=loc*2;   /* New object's potential location area */

        /* Get the lesser of the two objects below the location in heap */
        if(new_loc<heap->nobjs && (heap->heap[new_loc].val > heap->heap[new_loc+1].val))
            new_loc++;

        /* Check if the object is greater than the larger of the objects below it */
        /* If so, its in the correct location now, and we can get out */
        if(val <= heap->heap[new_loc].val)
            break;

        /* Move the greater of the two objects below the current location up */
        heap->heap[loc].val=heap->heap[new_loc].val;
        heap->heap[loc].obj=heap->heap[new_loc].obj;

        /* Update heap location for object which moved */
        heap->heap[loc].obj->heap_loc=loc;

        /* Move to location "below" current location */
        loc=new_loc;
    } /* end while */

    /* Put object into heap at correct location */
    heap->heap[loc].val=val;
    heap->heap[loc].obj=obj;

    /* Update heap location for object */
    heap->heap[loc].obj->heap_loc=loc;

    FUNC_LEAVE_NOAPI(ret_value);
} /* end H5HP_sink_min() */


/*--------------------------------------------------------------------------
 NAME
    H5HP_create
 PURPOSE
    Create a heap
 USAGE
    H5HP_t *H5HP_create(heap_type)
        H5HP_type_t heap_type;          IN: Type of heap to create

 RETURNS
    Returns a pointer to a heap on success, NULL on failure.
 DESCRIPTION
    Create a priority queue.  The SIZE is used to set the initial number of
    entries allocated.
 GLOBAL VARIABLES
 COMMENTS, BUGS, ASSUMPTIONS
 EXAMPLES
 REVISION LOG
--------------------------------------------------------------------------*/
H5HP_t *
H5HP_create(H5HP_type_t heap_type)
{
    H5HP_t *new_heap=NULL;      /* Pointer to new heap object created */
    H5HP_t *ret_value;          /* Return value */

    FUNC_ENTER_NOAPI(H5HP_create,NULL);

    /* Check args */
    assert(heap_type==H5HP_MIN_HEAP || heap_type==H5HP_MAX_HEAP);

    /* Allocate ref-counted string structure */
    if((new_heap=H5FL_MALLOC(H5HP_t))==NULL)
        HGOTO_ERROR(H5E_HEAP,H5E_NOSPACE,NULL,"memory allocation failed");

    /* Allocate the array to store the heap entries */
    if((new_heap->heap=H5FL_ARR_MALLOC(H5HP_ent_t, H5HP_START_SIZE+1))==NULL)
        HGOTO_ERROR(H5E_HEAP,H5E_NOSPACE,NULL,"memory allocation failed");

    /* Set the internal fields */
    new_heap->type=heap_type;
    new_heap->nobjs=0;
    new_heap->nalloc=H5HP_START_SIZE+1;

    /* Set the information in the 0'th location based on the type of heap */
    if(heap_type==H5HP_MIN_HEAP) {
        /* Set the value in the '0' location to be the minimum value, to
         * simplify the algorithms
         */
        new_heap->heap[0].val=INT_MIN;
        new_heap->heap[0].obj=NULL;
    } /* end if */
    else {
        /* Set the value in the '0' location to be the maximum value, to
         * simplify the algorithms
         */
        new_heap->heap[0].val=INT_MAX;
        new_heap->heap[0].obj=NULL;
    } /* end else */

    /* Set the return value */
    ret_value=new_heap;

done:
    /* Error cleanup */
    if(ret_value==NULL) {
        if(new_heap!=NULL) {
            if(new_heap->heap!=NULL)
                H5FL_ARR_FREE(H5HP_ent_t,new_heap->heap);
            H5FL_FREE(H5HP_t,new_heap);
        } /* end if */
    } /* end if */

    FUNC_LEAVE_NOAPI(ret_value);
} /* end H5HP_create() */


/*--------------------------------------------------------------------------
 NAME
    H5HP_count
 PURPOSE
    Check the number of elements in a heap
 USAGE
    ssize_t H5HP_count(heap)
        const H5HP_t *heap;     IN: Pointer to heap to query

 RETURNS
    Returns non-negative on success, negative on failure.
 DESCRIPTION
    Checks the number of elements in heap
 GLOBAL VARIABLES
 COMMENTS, BUGS, ASSUMPTIONS
 EXAMPLES
 REVISION LOG
--------------------------------------------------------------------------*/
ssize_t
H5HP_count(const H5HP_t *heap)
{
    ssize_t ret_value;   /* Return value */

    FUNC_ENTER_NOAPI(H5HP_count,FAIL);

    /* Check args */
    assert(heap);

    /* Check internal consistency */
    /* (Pre-condition) */
    assert(heap->nobjs<heap->nalloc);
    assert(heap->heap);
    assert((heap->type==H5HP_MAX_HEAP && heap->heap[0].val==INT_MAX) ||
        (heap->type==H5HP_MIN_HEAP && heap->heap[0].val==INT_MIN));
    assert(heap->heap[0].obj==NULL);

    /* Return the number of objects in the heap */
    H5_CHECK_OVERFLOW(heap->nobjs,size_t,ssize_t);
    ret_value=(ssize_t)heap->nobjs;

done:
    /* No post-condition check necessary, since heap is constant */

    FUNC_LEAVE_NOAPI(ret_value);
} /* end H5HP_count() */


/*--------------------------------------------------------------------------
 NAME
    H5HP_insert
 PURPOSE
    Insert an object into a heap, with an initial value
 USAGE
    herr_t H5HP_insert(heap, val, obj)
        H5HP_t *heap;           IN/OUT: Pointer to heap to modify
        int val;                IN: Initial value for object in heap
        void *obj;              IN: Pointer to object to insert into heap

 RETURNS
    Returns non-negative on success, negative on failure.
 DESCRIPTION
    Inserts a OBJ into a HEAP, with an initial VALue.
 GLOBAL VARIABLES
 COMMENTS, BUGS, ASSUMPTIONS
 EXAMPLES
 REVISION LOG
--------------------------------------------------------------------------*/
herr_t
H5HP_insert(H5HP_t *heap, int val, void *obj)
{
    herr_t ret_value=SUCCEED;   /* Return value */

    FUNC_ENTER_NOAPI(H5HP_insert,FAIL);

    /* Check args */
    assert(heap);
    assert(obj);

    /* Check internal consistency */
    /* (Pre-condition) */
    assert(heap->nobjs<heap->nalloc);
    assert(heap->heap);
    assert((heap->type==H5HP_MAX_HEAP && heap->heap[0].val==INT_MAX) ||
        (heap->type==H5HP_MIN_HEAP && heap->heap[0].val==INT_MIN));
    assert(heap->heap[0].obj==NULL);

    /* Increment number of objects in heap */
    heap->nobjs++;

    /* Check if we need to allocate more room for heap array */
    if(heap->nobjs>=heap->nalloc) {
        size_t n = MAX(H5HP_START_SIZE, 2*(heap->nalloc-1)) + 1;
        H5HP_ent_t *new_heap = H5FL_ARR_REALLOC(H5HP_ent_t,heap->heap, n);

        if (!new_heap)
            HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL, "unable to extend heap array");
        heap->heap = new_heap;
        heap->nalloc = n;
    } /* end if */

    /* Insert new object at end of heap */
    heap->heap[heap->nobjs].val=val;
    heap->heap[heap->nobjs].obj=obj;
    heap->heap[heap->nobjs].obj->heap_loc=heap->nobjs;

    /* Restore heap condition */
    if(heap->type==H5HP_MAX_HEAP) {
        if(H5HP_swim_max(heap,heap->nobjs)<0)
            HGOTO_ERROR(H5E_HEAP, H5E_CANTINSERT, FAIL, "unable to restore heap condition");
    } /* end if */
    else {
        if(H5HP_swim_min(heap,heap->nobjs)<0)
            HGOTO_ERROR(H5E_HEAP, H5E_CANTINSERT, FAIL, "unable to restore heap condition");
    } /* end else */

done:

    /* Check internal consistency */
    /* (Post-condition) */
    assert(heap->nobjs<heap->nalloc);
    assert(heap->heap);
    assert((heap->type==H5HP_MAX_HEAP && heap->heap[0].val==INT_MAX) ||
        (heap->type==H5HP_MIN_HEAP && heap->heap[0].val==INT_MIN));
    assert(heap->heap[0].obj==NULL);

    FUNC_LEAVE_NOAPI(ret_value);
} /* end H5HP_insert() */


/*--------------------------------------------------------------------------
 NAME
    H5HP_top
 PURPOSE
    Check the value of the top object in the heap
 USAGE
    herr_t H5HP_top(heap, val)
        const H5HP_t *heap;     IN: Pointer to heap to modify
        int val;                IN/OUT: Initial value for object in heap

 RETURNS
    Returns non-negative on success, negative on failure.
 DESCRIPTION
    Checks the value of the top object in a heap
 GLOBAL VARIABLES
 COMMENTS, BUGS, ASSUMPTIONS
 EXAMPLES
 REVISION LOG
--------------------------------------------------------------------------*/
herr_t
H5HP_top(const H5HP_t *heap, int *val)
{
    herr_t ret_value=SUCCEED;   /* Return value */

    FUNC_ENTER_NOAPI(H5HP_top,FAIL);

    /* Check args */
    assert(heap);
    assert(val);

    /* Check internal consistency */
    /* (Pre-condition) */
    assert(heap->nobjs<heap->nalloc);
    assert(heap->heap);
    assert((heap->type==H5HP_MAX_HEAP && heap->heap[0].val==INT_MAX) ||
        (heap->type==H5HP_MIN_HEAP && heap->heap[0].val==INT_MIN));
    assert(heap->heap[0].obj==NULL);

    /* Get value of the top object in the heap */
    *val=heap->heap[1].val;

done:

    /* No post-condition check necessary, since heap is constant */

    FUNC_LEAVE_NOAPI(ret_value);
} /* end H5HP_top() */


/*--------------------------------------------------------------------------
 NAME
    H5HP_remove
 PURPOSE
    Remove an object into a heap
 USAGE
    herr_t H5HP_remove(heap, val, obj)
        H5HP_t *heap;           IN/OUT: Pointer to heap to modify
        int *val;               OUT: Pointer to value of object removed from heap
        void **obj;             OUT: Pointer to object removed from heap

 RETURNS
    Returns non-negative on success, negative on failure.
 DESCRIPTION
    Removes the top object on a heap, returning its value and object pointer
 GLOBAL VARIABLES
 COMMENTS, BUGS, ASSUMPTIONS
 EXAMPLES
 REVISION LOG
--------------------------------------------------------------------------*/
herr_t
H5HP_remove(H5HP_t *heap, int *val, void **obj)
{
    herr_t ret_value=SUCCEED;   /* Return value */

    FUNC_ENTER_NOAPI(H5HP_remove,FAIL);

    /* Check args */
    assert(heap);
    assert(val);
    assert(obj);

    /* Check internal consistency */
    /* (Pre-condition) */
    assert(heap->nobjs<heap->nalloc);
    assert(heap->heap);
    assert((heap->type==H5HP_MAX_HEAP && heap->heap[0].val==INT_MAX) ||
        (heap->type==H5HP_MIN_HEAP && heap->heap[0].val==INT_MIN));
    assert(heap->heap[0].obj==NULL);

    /* Check if there are any objects on the heap to remove */
    if(heap->nobjs==0)
        HGOTO_ERROR(H5E_HEAP, H5E_NOTFOUND, FAIL, "heap is empty");

    /* Get the information for the top object on the heap */
    assert(heap->heap[1].obj->heap_loc==1);
    *val=heap->heap[1].val;
    *obj=heap->heap[1].obj;

    /* Move the last element in the heap to the top */
    heap->heap[1].val=heap->heap[heap->nobjs].val;
    heap->heap[1].obj=heap->heap[heap->nobjs].obj;
    heap->heap[1].obj->heap_loc=1;

    /* Decrement number of objects in heap */
    heap->nobjs--;

    /* Restore heap condition, if there are objects on the heap */
    if(heap->nobjs>0) {
        if(heap->type==H5HP_MAX_HEAP) {
            if(H5HP_sink_max(heap,1)<0)
                HGOTO_ERROR(H5E_HEAP, H5E_CANTDELETE, FAIL, "unable to restore heap condition");
        } /* end if */
        else {
            if(H5HP_sink_min(heap,1)<0)
                HGOTO_ERROR(H5E_HEAP, H5E_CANTDELETE, FAIL, "unable to restore heap condition");
        } /* end else */
    } /* end if */

done:

    /* Check internal consistency */
    /* (Post-condition) */
    assert(heap->nobjs<heap->nalloc);
    assert(heap->heap);
    assert((heap->type==H5HP_MAX_HEAP && heap->heap[0].val==INT_MAX) ||
        (heap->type==H5HP_MIN_HEAP && heap->heap[0].val==INT_MIN));
    assert(heap->heap[0].obj==NULL);

    FUNC_LEAVE_NOAPI(ret_value);
} /* end H5HP_remove() */


/*--------------------------------------------------------------------------
 NAME
    H5HP_change
 PURPOSE
    Change the priority of an object on a heap
 USAGE
    herr_t H5HP_change(heap, val, obj)
        H5HP_t *heap;           IN/OUT: Pointer to heap to modify
        int val;                IN: New priority value for object
        void *obj;              IN: Pointer to object to modify

 RETURNS
    Returns non-negative on success, negative on failure.
 DESCRIPTION
    Changes the priority of an object on a heap.
 GLOBAL VARIABLES
 COMMENTS, BUGS, ASSUMPTIONS
 EXAMPLES
 REVISION LOG
--------------------------------------------------------------------------*/
herr_t
H5HP_change(H5HP_t *heap, int val, void *_obj)
{
    H5HP_info_t *obj=(H5HP_info_t *)_obj;       /* Alias for object */
    size_t obj_loc;             /* Location of object in heap */
    int old_val;                /* Object's old priority value */
    herr_t ret_value=SUCCEED;   /* Return value */

    FUNC_ENTER_NOAPI(H5HP_change,FAIL);

    /* Check args */
    assert(heap);
    assert(obj);

    /* Check internal consistency */
    /* (Pre-condition) */
    assert(heap->nobjs<heap->nalloc);
    assert(heap->heap);
    assert((heap->type==H5HP_MAX_HEAP && heap->heap[0].val==INT_MAX) ||
        (heap->type==H5HP_MIN_HEAP && heap->heap[0].val==INT_MIN));
    assert(heap->heap[0].obj==NULL);

    /* Get the location of the object in the heap */
    obj_loc=obj->heap_loc;
    assert(obj_loc>0 && obj_loc<=heap->nobjs);

    /* Change the heap object's priority */
    old_val=heap->heap[obj_loc].val;
    heap->heap[obj_loc].val=val;

    /* Restore heap condition */
    if(val<old_val) {
        if(heap->type==H5HP_MAX_HEAP) {
            if(H5HP_sink_max(heap,obj_loc)<0)
                HGOTO_ERROR(H5E_HEAP, H5E_CANTCHANGE, FAIL, "unable to restore heap condition");
        } /* end if */
        else {
            if(H5HP_swim_min(heap,obj_loc)<0)
                HGOTO_ERROR(H5E_HEAP, H5E_CANTCHANGE, FAIL, "unable to restore heap condition");
        } /* end else */
    } /* end if */
    else {
        if(heap->type==H5HP_MAX_HEAP) {
            if(H5HP_swim_max(heap,obj_loc)<0)
                HGOTO_ERROR(H5E_HEAP, H5E_CANTCHANGE, FAIL, "unable to restore heap condition");
        } /* end if */
        else {
            if(H5HP_sink_min(heap,obj_loc)<0)
                HGOTO_ERROR(H5E_HEAP, H5E_CANTCHANGE, FAIL, "unable to restore heap condition");
        } /* end else */
    } /* end else */

done:

    /* Check internal consistency */
    /* (Post-condition) */
    assert(heap->nobjs<heap->nalloc);
    assert(heap->heap);
    assert((heap->type==H5HP_MAX_HEAP && heap->heap[0].val==INT_MAX) ||
        (heap->type==H5HP_MIN_HEAP && heap->heap[0].val==INT_MIN));
    assert(heap->heap[0].obj==NULL);

    FUNC_LEAVE_NOAPI(ret_value);
} /* end H5HP_change() */


/*--------------------------------------------------------------------------
 NAME
    H5HP_incr
 PURPOSE
    Increment the priority of an object on a heap
 USAGE
    herr_t H5HP_incr(heap, amt, obj)
        H5HP_t *heap;           IN/OUT: Pointer to heap to modify
        unsigned amt;           IN: Amount to increase priority by
        void *obj;              IN: Pointer to object to modify

 RETURNS
    Returns non-negative on success, negative on failure.
 DESCRIPTION
    Increments the priority of an object on a heap by one.
 GLOBAL VARIABLES
 COMMENTS, BUGS, ASSUMPTIONS
 EXAMPLES
 REVISION LOG
--------------------------------------------------------------------------*/
herr_t
H5HP_incr(H5HP_t *heap, unsigned amt, void *_obj)
{
    H5HP_info_t *obj=(H5HP_info_t *)_obj;       /* Alias for object */
    size_t obj_loc;             /* Location of object in heap */
    herr_t ret_value=SUCCEED;   /* Return value */

    FUNC_ENTER_NOAPI(H5HP_incr,FAIL);

    /* Check args */
    assert(heap);
    assert(obj);

    /* Check internal consistency */
    /* (Pre-condition) */
    assert(heap->nobjs<heap->nalloc);
    assert(heap->heap);
    assert((heap->type==H5HP_MAX_HEAP && heap->heap[0].val==INT_MAX) ||
        (heap->type==H5HP_MIN_HEAP && heap->heap[0].val==INT_MIN));
    assert(heap->heap[0].obj==NULL);

    /* Get the location of the object in the heap */
    obj_loc=obj->heap_loc;
    assert(obj_loc>0 && obj_loc<=heap->nobjs);

    /* Change the heap object's priority */
    heap->heap[obj_loc].val+=amt;

    /* Restore heap condition */
    if(heap->type==H5HP_MAX_HEAP) {
        if(H5HP_swim_max(heap,obj_loc)<0)
            HGOTO_ERROR(H5E_HEAP, H5E_CANTCHANGE, FAIL, "unable to restore heap condition");
    } /* end if */
    else {
        if(H5HP_sink_min(heap,obj_loc)<0)
            HGOTO_ERROR(H5E_HEAP, H5E_CANTCHANGE, FAIL, "unable to restore heap condition");
    } /* end else */

done:

    /* Check internal consistency */
    /* (Post-condition) */
    assert(heap->nobjs<heap->nalloc);
    assert(heap->heap);
    assert((heap->type==H5HP_MAX_HEAP && heap->heap[0].val==INT_MAX) ||
        (heap->type==H5HP_MIN_HEAP && heap->heap[0].val==INT_MIN));
    assert(heap->heap[0].obj==NULL);

    FUNC_LEAVE_NOAPI(ret_value);
} /* end H5HP_incr() */


/*--------------------------------------------------------------------------
 NAME
    H5HP_decr
 PURPOSE
    Decrement the priority of an object on a heap
 USAGE
    herr_t H5HP_dec(heap, amt, obj)
        H5HP_t *heap;           IN/OUT: Pointer to heap to modify
        unsigned amt;           IN: Amount to decrease priority by
        void *obj;              IN: Pointer to object to modify

 RETURNS
    Returns non-negative on success, negative on failure.
 DESCRIPTION
    Decrements the priority of an object on a heap by one.
 GLOBAL VARIABLES
 COMMENTS, BUGS, ASSUMPTIONS
 EXAMPLES
 REVISION LOG
--------------------------------------------------------------------------*/
herr_t
H5HP_decr(H5HP_t *heap, unsigned amt, void *_obj)
{
    H5HP_info_t *obj=(H5HP_info_t *)_obj;       /* Alias for object */
    size_t obj_loc;             /* Location of object in heap */
    herr_t ret_value=SUCCEED;   /* Return value */

    FUNC_ENTER_NOAPI(H5HP_decr,FAIL);

    /* Check args */
    assert(heap);
    assert(obj);

    /* Check internal consistency */
    /* (Pre-condition) */
    assert(heap->nobjs<heap->nalloc);
    assert(heap->heap);
    assert((heap->type==H5HP_MAX_HEAP && heap->heap[0].val==INT_MAX) ||
        (heap->type==H5HP_MIN_HEAP && heap->heap[0].val==INT_MIN));
    assert(heap->heap[0].obj==NULL);

    /* Get the location of the object in the heap */
    obj_loc=obj->heap_loc;
    assert(obj_loc>0 && obj_loc<=heap->nobjs);

    /* Change the heap object's priority */
    heap->heap[obj_loc].val-=amt;

    /* Restore heap condition */
    if(heap->type==H5HP_MAX_HEAP) {
        if(H5HP_sink_max(heap,obj_loc)<0)
            HGOTO_ERROR(H5E_HEAP, H5E_CANTCHANGE, FAIL, "unable to restore heap condition");
    } /* end if */
    else {
        if(H5HP_swim_min(heap,obj_loc)<0)
            HGOTO_ERROR(H5E_HEAP, H5E_CANTCHANGE, FAIL, "unable to restore heap condition");
    } /* end else */

done:

    /* Check internal consistency */
    /* (Post-condition) */
    assert(heap->nobjs<heap->nalloc);
    assert(heap->heap);
    assert((heap->type==H5HP_MAX_HEAP && heap->heap[0].val==INT_MAX) ||
        (heap->type==H5HP_MIN_HEAP && heap->heap[0].val==INT_MIN));
    assert(heap->heap[0].obj==NULL);

    FUNC_LEAVE_NOAPI(ret_value);
} /* end H5HP_decr() */


/*--------------------------------------------------------------------------
 NAME
    H5HP_close
 PURPOSE
    Close a heap, deallocating it.
 USAGE
    herr_t H5HP_close(heap)
        H5HP_t *heap;            IN/OUT: Pointer to heap to close

 RETURNS
    Returns non-negative on success, negative on failure.
 DESCRIPTION
    Close a heap, freeing all internal information.  Any objects left in
    the heap are not deallocated.
 GLOBAL VARIABLES
 COMMENTS, BUGS, ASSUMPTIONS
 EXAMPLES
 REVISION LOG
--------------------------------------------------------------------------*/
herr_t
H5HP_close(H5HP_t *heap)
{
    herr_t ret_value=SUCCEED;   /* Return value */

    FUNC_ENTER_NOAPI(H5HP_close,FAIL);

    /* Check args */
    assert(heap);

    /* Check internal consistency */
    /* (Pre-condition) */
    assert(heap->nobjs<heap->nalloc);
    assert(heap->heap);
    assert((heap->type==H5HP_MAX_HEAP && heap->heap[0].val==INT_MAX) ||
        (heap->type==H5HP_MIN_HEAP && heap->heap[0].val==INT_MIN));
    assert(heap->heap[0].obj==NULL);

    /* Free internal structures for heap */
    H5FL_ARR_FREE(H5HP_ent_t,heap->heap);

    /* Free actual heap object */
    H5FL_FREE(H5HP_t,heap);

done:
    FUNC_LEAVE_NOAPI(ret_value);
} /* end H5HP_close() */