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
|
/* -*- Mode:C++; c-basic-offset:8; tab-width:8; indent-tabs-mode:t -*- */
/*
* Copyright (C) 1997 by the University of Southern California
* $Id: heap.h,v 1.9 2005/08/25 18:58:02 johnh Exp $
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA.
*
*
* The copyright of this module includes the following
* linking-with-specific-other-licenses addition:
*
* In addition, as a special exception, the copyright holders of
* this module give you permission to combine (via static or
* dynamic linking) this module with free software programs or
* libraries that are released under the GNU LGPL and with code
* included in the standard release of ns-2 under the Apache 2.0
* license or under otherwise-compatible licenses with advertising
* requirements (or modified versions of such code, with unchanged
* license). You may copy and distribute such a system following the
* terms of the GNU GPL for this module and the licenses of the
* other code concerned, provided that you include the source code of
* that other code when and as the GNU GPL requires distribution of
* source code.
*
* Note that people who make modified versions of this module
* are not obligated to grant this special exception for their
* modified versions; it is their choice whether to do so. The GNU
* General Public License gives permission to release a modified
* version without this exception; this exception also makes it
* possible to release a modified version which carries forward this
* exception.
*
*/
/*
* @(#) $Header: /cvsroot/nsnam/ns-2/common/heap.h,v 1.9 2005/08/25 18:58:02 johnh Exp $ (USC/ISI)
*/
#ifndef ns_heap_h
#define ns_heap_h
#define HEAP_DEFAULT_SIZE 32
// This code has a long and rich history. It was stolen from the MaRS-2.0
// distribution, that had in its turn acquired it from the NetSim
// distribution (or so I have been told). It has been customised for
// event queue handling. I, Kannan, added prolific comments to it in order
// to better understand the data structure for myself, and turned into
// a standalone C++ class that you see in this version now.
typedef double heap_key_t;
typedef unsigned long heap_secondary_key_t;
// This code has (atleast?) one flaw: It does not check for memory allocated,
// especially in the constructor, and in heap_insert() when trying
// to resize the h_elems[] array.
class Heap
{
struct Heap_elem {
heap_key_t he_key;
heap_secondary_key_t he_s_key;
void* he_elem;
} *h_elems;
unsigned int h_s_key;
unsigned int h_size;
unsigned int h_maxsize;
unsigned int h_iter;
unsigned int parent(unsigned int i) { return ((i - 1) / 2); }
unsigned int left(unsigned int i) { return ((i * 2) + 1); }
unsigned int right(unsigned int i) { return ((i + 1) * 2); }
void swap(unsigned int i, unsigned int j) {
// swap elems[i] with elems[j] in this
Heap_elem __he = h_elems[i];
h_elems[i] = h_elems[j];
h_elems[j] = __he;
return;
};
unsigned int KEY_LESS_THAN(heap_key_t k1, heap_secondary_key_t ks1,
heap_key_t k2, heap_secondary_key_t ks2) {
return (k1 < k2) || ((k1==k2)&&(ks1<ks2));
};
unsigned int KEY_LESS_OR_EQUAL_THAN(heap_key_t k1, heap_key_t k2) {
return (k1 <= k2);
};
public:
Heap(int size=HEAP_DEFAULT_SIZE);
~Heap();
/*
* int heap_member(Heap *h, void *elem): O(n) algorithm.
*/
int heap_member(void* elem);
/*
* int heap_delete(Heap *h, void *elem): O(n) algorithm
*
* Returns 1 for success, 0 otherwise.
*/
int heap_delete(void* elem);
/*
* Couple of functions to support iterating through all things on the
* heap without having to know what a heap looks like. To be used as
* follows:
*
* for (elem = heap_iter_init(h); elem; elem = heap_iter(h))
* Do whatever to the elem.
*
* You cannot use heap_iter to do anything but inspect the heap. If
* heap_insert(), heap_extract_min(), or heap_delete() are called
* while iterating through the heap, all bets are off.
*
* Tue Nov 14 20:17:59 PST 1995 -- kva
* Actually now, heap_create() initialises h_iter correctly,
* and heap_iter() correctly resets h_iter
* when the heap is traversed, So, we do not really need
* heap_iter_init() anymore, except to break off a current
* iteration and restart.
*/
void* heap_iter_init() {
h_iter = 1;
return heap_min();
};
void* heap_iter() {
if (h_iter >= h_size) {
h_iter = 0;
return 0;
} else {
return h_elems[h_iter++].he_elem;
}
};
/*
* void heap_insert(Heap *h, heap_key_t *key, void *elem)
*
* Insert <key, elem> into heap h.
* Adjust heap_size if we hit the limit.
*/
void heap_insert(heap_key_t key, void* elem);
/*
* void *heap_min(Heap *h)
*
* Returns the smallest element in the heap, if it exists,
* NULL otherwise. The element is still in the heap.
*/
void* heap_min() {
return (h_size > 0 ? h_elems[0].he_elem : 0);
};
/*
* void *heap_extract_min(Heap *h)
*
* Returns the smallest element in the heap, if it exists.
* NULL otherwise.
*/
void* heap_extract_min();
};
#endif /* ns_heap_h */
|
