1 | /* |
2 | * Copyright (c) 2015, Intel Corporation |
3 | * |
4 | * Redistribution and use in source and binary forms, with or without |
5 | * modification, are permitted provided that the following conditions are met: |
6 | * |
7 | * * Redistributions of source code must retain the above copyright notice, |
8 | * this list of conditions and the following disclaimer. |
9 | * * Redistributions in binary form must reproduce the above copyright |
10 | * notice, this list of conditions and the following disclaimer in the |
11 | * documentation and/or other materials provided with the distribution. |
12 | * * Neither the name of Intel Corporation nor the names of its contributors |
13 | * may be used to endorse or promote products derived from this software |
14 | * without specific prior written permission. |
15 | * |
16 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" |
17 | * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
18 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
19 | * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE |
20 | * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
21 | * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
22 | * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
23 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
24 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
25 | * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
26 | * POSSIBILITY OF SUCH DAMAGE. |
27 | */ |
28 | |
29 | #ifndef PQUEUE_H |
30 | #define PQUEUE_H |
31 | |
32 | #include "ue2common.h" |
33 | |
34 | static really_inline u32 |
35 | pq_left(u32 i) { |
36 | return (i << 1) + 1; |
37 | } |
38 | |
39 | static really_inline u32 |
40 | pq_right(u32 i) { |
41 | return (i << 1) + 2; |
42 | } |
43 | |
44 | static really_inline |
45 | u32 pq_parent(u32 i) { |
46 | return (i - 1) >> 1; |
47 | } |
48 | |
49 | static really_inline |
50 | void pq_sift(PQ_T *items, u32 start, u32 end) { |
51 | u32 j = start; |
52 | PQ_T j_temp = items[j]; |
53 | |
54 | while (pq_left(j) < end) { |
55 | u32 max_child; |
56 | |
57 | if (pq_right(j) < end && PQ_COMP(items, pq_right(j), pq_left(j))) { |
58 | max_child = pq_right(j); |
59 | } else { |
60 | max_child = pq_left(j); |
61 | } |
62 | |
63 | if (PQ_COMP_B(items, max_child, j_temp)) { |
64 | items[j] = items[max_child]; |
65 | j = max_child; |
66 | } else { |
67 | /* j is already less than its children. We know heap property |
68 | * is already maintained for children we are done */ |
69 | break; |
70 | } |
71 | } |
72 | items[j] = j_temp; |
73 | } |
74 | |
75 | static really_inline |
76 | PQ_T *pq_top(PQ_T *items) { |
77 | return items; |
78 | } |
79 | |
80 | static really_inline |
81 | void pq_pop(PQ_T *items, u32 item_count) { |
82 | item_count--; |
83 | items[0] = items[item_count]; |
84 | pq_sift(items, 0, item_count); |
85 | } |
86 | |
87 | static really_inline |
88 | void pq_insert(PQ_T *items, u32 item_count, PQ_T new_item) { |
89 | u32 pos = item_count; |
90 | while (pos) { |
91 | u32 parent = pq_parent(pos); |
92 | if (!PQ_COMP_B(items, parent, new_item)) { |
93 | items[pos] = items[parent]; |
94 | pos = parent; |
95 | } else { |
96 | break; |
97 | } |
98 | } |
99 | items[pos] = new_item; |
100 | } |
101 | |
102 | static really_inline |
103 | void pq_replace_top(PQ_T *items, u32 item_count, PQ_T new_item) { |
104 | items[0] = new_item; |
105 | pq_sift(items, 0, item_count); |
106 | } |
107 | |
108 | #endif |
109 | |
110 | |