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
|
/*
* Copyright (C) 2004-2007 Internet Systems Consortium, Inc. ("ISC")
* Copyright (C) 1997-2001 Internet Software Consortium.
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
* REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
* AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
* INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
* LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
* OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
* PERFORMANCE OF THIS SOFTWARE.
*/
/* $Id: heap.h,v 1.3 2007-05-19 19:16:25 dhankins Exp $ */
#ifndef ISC_HEAP_H
#define ISC_HEAP_H 1
/*! \file isc/heap.h */
/*%
* The comparision function returns ISC_TRUE if the first argument has
* higher priority than the second argument, and ISC_FALSE otherwise.
*/
typedef isc_boolean_t (*isc_heapcompare_t)(void *, void *);
/*%
* The index function allows the client of the heap to receive a callback
* when an item's index number changes. This allows it to maintain
* sync with its external state, but still delete itself, since deletions
* from the heap require the index be provided.
*/
typedef void (*isc_heapindex_t)(void *, unsigned int);
/*%
* The heapaction function is used when iterating over the heap.
*
* NOTE: The heap structure CANNOT BE MODIFIED during the call to
* isc_heap_foreach().
*/
typedef void (*isc_heapaction_t)(void *, void *);
typedef struct isc_heap isc_heap_t;
isc_result_t
isc_heap_create(isc_heapcompare_t compare,
isc_heapindex_t index, unsigned int size_increment,
isc_heap_t **heapp);
/*!<
* \brief Create a new heap. The heap is implemented using a space-efficient
* storage method. When the heap elements are deleted space is not freed
* but will be reused when new elements are inserted.
*
* Requires:
*\li "mctx" is valid.
*\li "compare" is a function which takes two void * arguments and
* returns ISC_TRUE if the first argument has a higher priority than
* the second, and ISC_FALSE otherwise.
*\li "index" is a function which takes a void *, and an unsigned int
* argument. This function will be called whenever an element's
* index value changes, so it may continue to delete itself from the
* heap. This option may be NULL if this functionality is unneeded.
*\li "size_increment" is a hint about how large the heap should grow
* when resizing is needed. If this is 0, a default size will be
* used, which is currently 1024, allowing space for an additional 1024
* heap elements to be inserted before adding more space.
*\li "heapp" is not NULL, and "*heap" is NULL.
*
* Returns:
*\li ISC_R_SUCCESS - success
*\li ISC_R_NOMEMORY - insufficient memory
*/
void
isc_heap_destroy(isc_heap_t **heapp);
/*!<
* \brief Destroys a heap.
*
* Requires:
*\li "heapp" is not NULL and "*heap" points to a valid isc_heap_t.
*/
isc_result_t
isc_heap_insert(isc_heap_t *heap, void *elt);
/*!<
* \brief Inserts a new element into a heap.
*
* Requires:
*\li "heapp" is not NULL and "*heap" points to a valid isc_heap_t.
*/
void
isc_heap_delete(isc_heap_t *heap, unsigned int index);
/*!<
* \brief Deletes an element from a heap, by element index.
*
* Requires:
*\li "heapp" is not NULL and "*heap" points to a valid isc_heap_t.
*\li "index" is a valid element index, as provided by the "index" callback
* provided during heap creation.
*/
void
isc_heap_increased(isc_heap_t *heap, unsigned int index);
/*!<
* \brief Indicates to the heap that an element's priority has increased.
* This function MUST be called whenever an element has increased in priority.
*
* Requires:
*\li "heapp" is not NULL and "*heap" points to a valid isc_heap_t.
*\li "index" is a valid element index, as provided by the "index" callback
* provided during heap creation.
*/
void
isc_heap_decreased(isc_heap_t *heap, unsigned int index);
/*!<
* \brief Indicates to the heap that an element's priority has decreased.
* This function MUST be called whenever an element has decreased in priority.
*
* Requires:
*\li "heapp" is not NULL and "*heap" points to a valid isc_heap_t.
*\li "index" is a valid element index, as provided by the "index" callback
* provided during heap creation.
*/
void *
isc_heap_element(isc_heap_t *heap, unsigned int index);
/*!<
* \brief Returns the element for a specific element index.
*
* Requires:
*\li "heapp" is not NULL and "*heap" points to a valid isc_heap_t.
*\li "index" is a valid element index, as provided by the "index" callback
* provided during heap creation.
*
* Returns:
*\li A pointer to the element for the element index.
*/
void
isc_heap_foreach(isc_heap_t *heap, isc_heapaction_t action, void *uap);
/*!<
* \brief Iterate over the heap, calling an action for each element. The
* order of iteration is not sorted.
*
* Requires:
*\li "heapp" is not NULL and "*heap" points to a valid isc_heap_t.
*\li "action" is not NULL, and is a function which takes two arguments.
* The first is a void *, representing the element, and the second is
* "uap" as provided to isc_heap_foreach.
*\li "uap" is a caller-provided argument, and may be NULL.
*
* Note:
*\li The heap structure CANNOT be modified during this iteration. The only
* safe function to call while iterating the heap is isc_heap_element().
*/
#endif /* ISC_HEAP_H */
|
