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Rev | Author | Line No. | Line |
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3243 | Serge | 1 | /* |
2 | Red Black Trees |
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3 | (C) 1999 Andrea Arcangeli |
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4 | |||
5 | This program is free software; you can redistribute it and/or modify |
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6 | it under the terms of the GNU General Public License as published by |
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7 | the Free Software Foundation; either version 2 of the License, or |
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8 | (at your option) any later version. |
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9 | |||
10 | This program is distributed in the hope that it will be useful, |
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11 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
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12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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13 | GNU General Public License for more details. |
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14 | |||
15 | You should have received a copy of the GNU General Public License |
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16 | along with this program; if not, write to the Free Software |
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17 | Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
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18 | |||
19 | linux/include/linux/rbtree.h |
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20 | |||
21 | To use rbtrees you'll have to implement your own insert and search cores. |
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22 | This will avoid us to use callbacks and to drop drammatically performances. |
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23 | I know it's not the cleaner way, but in C (not in C++) to get |
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24 | performances and genericity... |
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25 | |||
26 | See Documentation/rbtree.txt for documentation and samples. |
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27 | */ |
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28 | |||
29 | #ifndef _LINUX_RBTREE_H |
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30 | #define _LINUX_RBTREE_H |
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31 | |||
32 | #include |
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33 | #include |
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6102 | serge | 34 | #include |
3243 | Serge | 35 | |
36 | struct rb_node { |
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37 | unsigned long __rb_parent_color; |
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38 | struct rb_node *rb_right; |
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39 | struct rb_node *rb_left; |
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40 | } __attribute__((aligned(sizeof(long)))); |
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41 | /* The alignment might seem pointless, but allegedly CRIS needs it */ |
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42 | |||
43 | struct rb_root { |
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44 | struct rb_node *rb_node; |
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45 | }; |
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46 | |||
47 | |||
48 | #define rb_parent(r) ((struct rb_node *)((r)->__rb_parent_color & ~3)) |
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49 | |||
50 | #define RB_ROOT (struct rb_root) { NULL, } |
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51 | #define rb_entry(ptr, type, member) container_of(ptr, type, member) |
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52 | |||
6936 | serge | 53 | #define RB_EMPTY_ROOT(root) (READ_ONCE((root)->rb_node) == NULL) |
3243 | Serge | 54 | |
6082 | serge | 55 | /* 'empty' nodes are nodes that are known not to be inserted in an rbtree */ |
3243 | Serge | 56 | #define RB_EMPTY_NODE(node) \ |
57 | ((node)->__rb_parent_color == (unsigned long)(node)) |
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58 | #define RB_CLEAR_NODE(node) \ |
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59 | ((node)->__rb_parent_color = (unsigned long)(node)) |
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60 | |||
61 | |||
62 | extern void rb_insert_color(struct rb_node *, struct rb_root *); |
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63 | extern void rb_erase(struct rb_node *, struct rb_root *); |
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64 | |||
65 | |||
66 | /* Find logical next and previous nodes in a tree */ |
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67 | extern struct rb_node *rb_next(const struct rb_node *); |
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68 | extern struct rb_node *rb_prev(const struct rb_node *); |
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69 | extern struct rb_node *rb_first(const struct rb_root *); |
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70 | extern struct rb_node *rb_last(const struct rb_root *); |
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71 | |||
4103 | Serge | 72 | /* Postorder iteration - always visit the parent after its children */ |
73 | extern struct rb_node *rb_first_postorder(const struct rb_root *); |
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74 | extern struct rb_node *rb_next_postorder(const struct rb_node *); |
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75 | |||
3243 | Serge | 76 | /* Fast replacement of a single node without remove/rebalance/add/rebalance */ |
6082 | serge | 77 | extern void rb_replace_node(struct rb_node *victim, struct rb_node *new, |
3243 | Serge | 78 | struct rb_root *root); |
79 | |||
6082 | serge | 80 | static inline void rb_link_node(struct rb_node *node, struct rb_node *parent, |
81 | struct rb_node **rb_link) |
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3243 | Serge | 82 | { |
83 | node->__rb_parent_color = (unsigned long)parent; |
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84 | node->rb_left = node->rb_right = NULL; |
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85 | |||
86 | *rb_link = node; |
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87 | } |
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88 | |||
6082 | serge | 89 | static inline void rb_link_node_rcu(struct rb_node *node, struct rb_node *parent, |
90 | struct rb_node **rb_link) |
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91 | { |
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92 | node->__rb_parent_color = (unsigned long)parent; |
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93 | node->rb_left = node->rb_right = NULL; |
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94 | |||
95 | rcu_assign_pointer(*rb_link, node); |
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96 | } |
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97 | |||
5056 | serge | 98 | #define rb_entry_safe(ptr, type, member) \ |
99 | ({ typeof(ptr) ____ptr = (ptr); \ |
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100 | ____ptr ? rb_entry(____ptr, type, member) : NULL; \ |
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101 | }) |
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102 | |||
4103 | Serge | 103 | /** |
6082 | serge | 104 | * rbtree_postorder_for_each_entry_safe - iterate in post-order over rb_root of |
105 | * given type allowing the backing memory of @pos to be invalidated |
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4103 | Serge | 106 | * |
107 | * @pos: the 'type *' to use as a loop cursor. |
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108 | * @n: another 'type *' to use as temporary storage |
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109 | * @root: 'rb_root *' of the rbtree. |
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110 | * @field: the name of the rb_node field within 'type'. |
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6082 | serge | 111 | * |
112 | * rbtree_postorder_for_each_entry_safe() provides a similar guarantee as |
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113 | * list_for_each_entry_safe() and allows the iteration to continue independent |
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114 | * of changes to @pos by the body of the loop. |
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115 | * |
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116 | * Note, however, that it cannot handle other modifications that re-order the |
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117 | * rbtree it is iterating over. This includes calling rb_erase() on @pos, as |
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118 | * rb_erase() may rebalance the tree, causing us to miss some nodes. |
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4103 | Serge | 119 | */ |
120 | #define rbtree_postorder_for_each_entry_safe(pos, n, root, field) \ |
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5056 | serge | 121 | for (pos = rb_entry_safe(rb_first_postorder(root), typeof(*pos), field); \ |
122 | pos && ({ n = rb_entry_safe(rb_next_postorder(&pos->field), \ |
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123 | typeof(*pos), field); 1; }); \ |
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124 | pos = n) |
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4103 | Serge | 125 | |
3243 | Serge | 126 | #endif /* _LINUX_RBTREE_H */ |