2
* Copyright (c) 2006 Maxim Yegorushkin <maxim.yegorushkin@gmail.com>
5
* Redistribution and use in source and binary forms, with or without
6
* modification, are permitted provided that the following conditions
8
* 1. Redistributions of source code must retain the above copyright
9
* notice, this list of conditions and the following disclaimer.
10
* 2. Redistributions in binary form must reproduce the above copyright
11
* notice, this list of conditions and the following disclaimer in the
12
* documentation and/or other materials provided with the distribution.
13
* 3. The name of the author may not be used to endorse or promote products
14
* derived from this software without specific prior written permission.
16
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32
typedef struct min_heap
38
static inline void min_heap_ctor(min_heap_t* s);
39
static inline void min_heap_dtor(min_heap_t* s);
40
static inline void min_heap_elem_init(struct event* e);
41
static inline int min_heap_elem_greater(struct event *a, struct event *b);
42
static inline int min_heap_empty(min_heap_t* s);
43
static inline unsigned min_heap_size(min_heap_t* s);
44
static inline struct event* min_heap_top(min_heap_t* s);
45
static inline int min_heap_reserve(min_heap_t* s, unsigned n);
46
static inline int min_heap_push(min_heap_t* s, struct event* e);
47
static inline struct event* min_heap_pop(min_heap_t* s);
48
static inline int min_heap_erase(min_heap_t* s, struct event* e);
49
static inline void min_heap_shift_up_(min_heap_t* s, unsigned hole_index, struct event* e);
50
static inline void min_heap_shift_down_(min_heap_t* s, unsigned hole_index, struct event* e);
52
int min_heap_elem_greater(struct event *a, struct event *b)
54
return timercmp(&a->ev_timeout, &b->ev_timeout, >);
57
void min_heap_ctor(min_heap_t* s) { s->p = 0; s->n = 0; s->a = 0; }
58
void min_heap_dtor(min_heap_t* s) { free(s->p); }
59
void min_heap_elem_init(struct event* e) { e->min_heap_idx = -1; }
60
int min_heap_empty(min_heap_t* s) { return 0u == s->n; }
61
unsigned min_heap_size(min_heap_t* s) { return s->n; }
62
struct event* min_heap_top(min_heap_t* s) { return s->n ? *s->p : 0; }
64
int min_heap_push(min_heap_t* s, struct event* e)
66
if(min_heap_reserve(s, s->n + 1))
68
min_heap_shift_up_(s, s->n++, e);
72
struct event* min_heap_pop(min_heap_t* s)
76
struct event* e = *s->p;
78
min_heap_shift_down_(s, 0u, s->p[--s->n]);
84
int min_heap_erase(min_heap_t* s, struct event* e)
86
if(((unsigned int)-1) != e->min_heap_idx)
88
min_heap_shift_down_(s, e->min_heap_idx, s->p[--s->n]);
95
int min_heap_reserve(min_heap_t* s, unsigned n)
100
unsigned a = s->a ? s->a * 2 : 8;
103
if(!(p = (struct event**)realloc(s->p, a * sizeof *p)))
111
void min_heap_shift_up_(min_heap_t* s, unsigned hole_index, struct event* e)
113
unsigned parent = (hole_index - 1) / 2;
114
while(hole_index && min_heap_elem_greater(s->p[parent], e))
116
(s->p[hole_index] = s->p[parent])->min_heap_idx = hole_index;
118
parent = (hole_index - 1) / 2;
120
(s->p[hole_index] = e)->min_heap_idx = hole_index;
123
void min_heap_shift_down_(min_heap_t* s, unsigned hole_index, struct event* e)
125
unsigned min_child = 2 * (hole_index + 1);
126
while(min_child <= s->n)
128
min_child -= min_child == s->n || min_heap_elem_greater(s->p[min_child], s->p[min_child - 1]);
129
if(!(min_heap_elem_greater(e, s->p[min_child])))
131
(s->p[hole_index] = s->p[min_child])->min_heap_idx = hole_index;
132
hole_index = min_child;
133
min_child = 2 * (hole_index + 1);
135
min_heap_shift_up_(s, hole_index, e);
138
#endif /* _MIN_HEAP_H_ */