1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/ipc/chromium/src/third_party/libevent/minheap-internal.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,160 @@
1.4 +/*
1.5 + * Copyright (c) 2007-2012 Niels Provos and Nick Mathewson
1.6 + *
1.7 + * Copyright (c) 2006 Maxim Yegorushkin <maxim.yegorushkin@gmail.com>
1.8 + *
1.9 + * Redistribution and use in source and binary forms, with or without
1.10 + * modification, are permitted provided that the following conditions
1.11 + * are met:
1.12 + * 1. Redistributions of source code must retain the above copyright
1.13 + * notice, this list of conditions and the following disclaimer.
1.14 + * 2. Redistributions in binary form must reproduce the above copyright
1.15 + * notice, this list of conditions and the following disclaimer in the
1.16 + * documentation and/or other materials provided with the distribution.
1.17 + * 3. The name of the author may not be used to endorse or promote products
1.18 + * derived from this software without specific prior written permission.
1.19 + *
1.20 + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
1.21 + * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
1.22 + * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
1.23 + * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
1.24 + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
1.25 + * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
1.26 + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
1.27 + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
1.28 + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
1.29 + * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
1.30 + */
1.31 +#ifndef _MIN_HEAP_H_
1.32 +#define _MIN_HEAP_H_
1.33 +
1.34 +#include "event2/event-config.h"
1.35 +#include "event2/event.h"
1.36 +#include "event2/event_struct.h"
1.37 +#include "event2/util.h"
1.38 +#include "util-internal.h"
1.39 +#include "mm-internal.h"
1.40 +
1.41 +typedef struct min_heap
1.42 +{
1.43 + struct event** p;
1.44 + unsigned n, a;
1.45 +} min_heap_t;
1.46 +
1.47 +static inline void min_heap_ctor(min_heap_t* s);
1.48 +static inline void min_heap_dtor(min_heap_t* s);
1.49 +static inline void min_heap_elem_init(struct event* e);
1.50 +static inline int min_heap_elt_is_top(const struct event *e);
1.51 +static inline int min_heap_elem_greater(struct event *a, struct event *b);
1.52 +static inline int min_heap_empty(min_heap_t* s);
1.53 +static inline unsigned min_heap_size(min_heap_t* s);
1.54 +static inline struct event* min_heap_top(min_heap_t* s);
1.55 +static inline int min_heap_reserve(min_heap_t* s, unsigned n);
1.56 +static inline int min_heap_push(min_heap_t* s, struct event* e);
1.57 +static inline struct event* min_heap_pop(min_heap_t* s);
1.58 +static inline int min_heap_erase(min_heap_t* s, struct event* e);
1.59 +static inline void min_heap_shift_up_(min_heap_t* s, unsigned hole_index, struct event* e);
1.60 +static inline void min_heap_shift_down_(min_heap_t* s, unsigned hole_index, struct event* e);
1.61 +
1.62 +int min_heap_elem_greater(struct event *a, struct event *b)
1.63 +{
1.64 + return evutil_timercmp(&a->ev_timeout, &b->ev_timeout, >);
1.65 +}
1.66 +
1.67 +void min_heap_ctor(min_heap_t* s) { s->p = 0; s->n = 0; s->a = 0; }
1.68 +void min_heap_dtor(min_heap_t* s) { if (s->p) mm_free(s->p); }
1.69 +void min_heap_elem_init(struct event* e) { e->ev_timeout_pos.min_heap_idx = -1; }
1.70 +int min_heap_empty(min_heap_t* s) { return 0u == s->n; }
1.71 +unsigned min_heap_size(min_heap_t* s) { return s->n; }
1.72 +struct event* min_heap_top(min_heap_t* s) { return s->n ? *s->p : 0; }
1.73 +
1.74 +int min_heap_push(min_heap_t* s, struct event* e)
1.75 +{
1.76 + if (min_heap_reserve(s, s->n + 1))
1.77 + return -1;
1.78 + min_heap_shift_up_(s, s->n++, e);
1.79 + return 0;
1.80 +}
1.81 +
1.82 +struct event* min_heap_pop(min_heap_t* s)
1.83 +{
1.84 + if (s->n)
1.85 + {
1.86 + struct event* e = *s->p;
1.87 + min_heap_shift_down_(s, 0u, s->p[--s->n]);
1.88 + e->ev_timeout_pos.min_heap_idx = -1;
1.89 + return e;
1.90 + }
1.91 + return 0;
1.92 +}
1.93 +
1.94 +int min_heap_elt_is_top(const struct event *e)
1.95 +{
1.96 + return e->ev_timeout_pos.min_heap_idx == 0;
1.97 +}
1.98 +
1.99 +int min_heap_erase(min_heap_t* s, struct event* e)
1.100 +{
1.101 + if (-1 != e->ev_timeout_pos.min_heap_idx)
1.102 + {
1.103 + struct event *last = s->p[--s->n];
1.104 + unsigned parent = (e->ev_timeout_pos.min_heap_idx - 1) / 2;
1.105 + /* we replace e with the last element in the heap. We might need to
1.106 + shift it upward if it is less than its parent, or downward if it is
1.107 + greater than one or both its children. Since the children are known
1.108 + to be less than the parent, it can't need to shift both up and
1.109 + down. */
1.110 + if (e->ev_timeout_pos.min_heap_idx > 0 && min_heap_elem_greater(s->p[parent], last))
1.111 + min_heap_shift_up_(s, e->ev_timeout_pos.min_heap_idx, last);
1.112 + else
1.113 + min_heap_shift_down_(s, e->ev_timeout_pos.min_heap_idx, last);
1.114 + e->ev_timeout_pos.min_heap_idx = -1;
1.115 + return 0;
1.116 + }
1.117 + return -1;
1.118 +}
1.119 +
1.120 +int min_heap_reserve(min_heap_t* s, unsigned n)
1.121 +{
1.122 + if (s->a < n)
1.123 + {
1.124 + struct event** p;
1.125 + unsigned a = s->a ? s->a * 2 : 8;
1.126 + if (a < n)
1.127 + a = n;
1.128 + if (!(p = (struct event**)mm_realloc(s->p, a * sizeof *p)))
1.129 + return -1;
1.130 + s->p = p;
1.131 + s->a = a;
1.132 + }
1.133 + return 0;
1.134 +}
1.135 +
1.136 +void min_heap_shift_up_(min_heap_t* s, unsigned hole_index, struct event* e)
1.137 +{
1.138 + unsigned parent = (hole_index - 1) / 2;
1.139 + while (hole_index && min_heap_elem_greater(s->p[parent], e))
1.140 + {
1.141 + (s->p[hole_index] = s->p[parent])->ev_timeout_pos.min_heap_idx = hole_index;
1.142 + hole_index = parent;
1.143 + parent = (hole_index - 1) / 2;
1.144 + }
1.145 + (s->p[hole_index] = e)->ev_timeout_pos.min_heap_idx = hole_index;
1.146 +}
1.147 +
1.148 +void min_heap_shift_down_(min_heap_t* s, unsigned hole_index, struct event* e)
1.149 +{
1.150 + unsigned min_child = 2 * (hole_index + 1);
1.151 + while (min_child <= s->n)
1.152 + {
1.153 + min_child -= min_child == s->n || min_heap_elem_greater(s->p[min_child], s->p[min_child - 1]);
1.154 + if (!(min_heap_elem_greater(e, s->p[min_child])))
1.155 + break;
1.156 + (s->p[hole_index] = s->p[min_child])->ev_timeout_pos.min_heap_idx = hole_index;
1.157 + hole_index = min_child;
1.158 + min_child = 2 * (hole_index + 1);
1.159 + }
1.160 + (s->p[hole_index] = e)->ev_timeout_pos.min_heap_idx = hole_index;
1.161 +}
1.162 +
1.163 +#endif /* _MIN_HEAP_H_ */
