Niranjan Yadla | 19336af | 2018-04-19 12:19:27 -0700 | [diff] [blame^] | 1 | /******************************************************************************* |
| 2 | * Copyright (C) 2018 Cadence Design Systems, Inc. |
| 3 | * |
| 4 | * Permission is hereby granted, free of charge, to any person obtaining |
| 5 | * a copy of this software and associated documentation files (the |
| 6 | * "Software"), to use this Software with Cadence processor cores only and |
| 7 | * not with any other processors and platforms, subject to |
| 8 | * the following conditions: |
| 9 | * |
| 10 | * The above copyright notice and this permission notice shall be included |
| 11 | * in all copies or substantial portions of the Software. |
| 12 | * |
| 13 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, |
| 14 | * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF |
| 15 | * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. |
| 16 | * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY |
| 17 | * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, |
| 18 | * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE |
| 19 | * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. |
| 20 | |
| 21 | ******************************************************************************/ |
| 22 | |
| 23 | /******************************************************************************* |
| 24 | * rbtree.h |
| 25 | * |
| 26 | * Generic implmentation of red-black trees |
| 27 | * |
| 28 | *******************************************************************************/ |
| 29 | |
| 30 | #ifndef __RBTREE_H |
| 31 | #define __RBTREE_H |
| 32 | |
| 33 | /******************************************************************************* |
| 34 | * Red-black tree node definition |
| 35 | ******************************************************************************/ |
| 36 | |
| 37 | /* ...reference to rb-tree node */ |
| 38 | typedef struct rb_node *rb_idx_t; |
| 39 | |
| 40 | /* ...rb-tree node */ |
| 41 | typedef struct rb_node |
| 42 | { |
| 43 | /* ...pointers to parent and two children */ |
| 44 | rb_idx_t parent, left, right; |
| 45 | |
| 46 | /* ...node color (least-significant-bit only) */ |
| 47 | u32 color; |
| 48 | |
| 49 | } rb_node_t; |
| 50 | |
| 51 | /* ...rb-tree data */ |
| 52 | typedef struct rb_tree_t |
| 53 | { |
| 54 | /* ...tree sentinel node */ |
| 55 | rb_node_t root; |
| 56 | |
| 57 | } rb_tree_t; |
| 58 | |
| 59 | /******************************************************************************* |
| 60 | * Helpers |
| 61 | ******************************************************************************/ |
| 62 | |
| 63 | /* ...left child accessor */ |
| 64 | static inline rb_idx_t rb_left(rb_tree_t *tree, rb_idx_t n_idx) |
| 65 | { |
| 66 | return n_idx->left; |
| 67 | } |
| 68 | |
| 69 | /* ...right child accessor */ |
| 70 | static inline rb_idx_t rb_right(rb_tree_t *tree, rb_idx_t n_idx) |
| 71 | { |
| 72 | return n_idx->right; |
| 73 | } |
| 74 | |
| 75 | /* ...parent node accessor */ |
| 76 | static inline rb_idx_t rb_parent(rb_tree_t *tree, rb_idx_t n_idx) |
| 77 | { |
| 78 | return n_idx->parent; |
| 79 | } |
| 80 | |
| 81 | /* ...tree root node accessor */ |
| 82 | static inline rb_idx_t rb_root(rb_tree_t *tree) |
| 83 | { |
| 84 | return rb_left(tree, &tree->root); |
| 85 | } |
| 86 | |
| 87 | /* ...tree data pointer accessor */ |
| 88 | static inline rb_idx_t rb_cache(rb_tree_t *tree) |
| 89 | { |
| 90 | return rb_right(tree, &tree->root); |
| 91 | } |
| 92 | |
| 93 | /* ...tree null node */ |
| 94 | static inline rb_idx_t rb_null(rb_tree_t *tree) |
| 95 | { |
| 96 | return &tree->root; |
| 97 | } |
| 98 | |
| 99 | /* ...get user-bits stored in node color */ |
| 100 | static inline u32 rb_node_data(rb_tree_t *tree, rb_idx_t n_idx) |
| 101 | { |
| 102 | return (n_idx->color >> 1); |
| 103 | } |
| 104 | |
| 105 | /* ...left child assignment */ |
| 106 | static inline void rb_set_left(rb_tree_t *tree, rb_idx_t n_idx, rb_node_t *child) |
| 107 | { |
| 108 | n_idx->left = child; |
| 109 | } |
| 110 | |
| 111 | /* ...right child assignment */ |
| 112 | static inline void rb_set_right(rb_tree_t *tree, rb_idx_t n_idx, rb_node_t *child) |
| 113 | { |
| 114 | n_idx->right = child; |
| 115 | } |
| 116 | |
| 117 | /* ...cache tree client index */ |
| 118 | static inline void rb_set_cache(rb_tree_t *tree, rb_idx_t c_idx) |
| 119 | { |
| 120 | tree->root.right = c_idx; |
| 121 | } |
| 122 | |
| 123 | /* ...get user-bits stored in node color */ |
| 124 | static inline void rb_set_node_data(rb_tree_t *tree, rb_idx_t n_idx, u32 data) |
| 125 | { |
| 126 | n_idx->color = (n_idx->color & 0x1) | (data << 1); |
| 127 | } |
| 128 | |
| 129 | /******************************************************************************* |
| 130 | * API functions |
| 131 | ******************************************************************************/ |
| 132 | |
| 133 | /* ...initialize rb-tree */ |
| 134 | extern void rb_init(rb_tree_t *tree); |
| 135 | |
| 136 | /* ...insert node into tree as a child of p */ |
| 137 | extern void rb_insert(rb_tree_t *tree, rb_idx_t n_idx, rb_idx_t p_idx); |
| 138 | |
| 139 | /* ...replace the node with same-key value and fixup tree pointers */ |
| 140 | extern void rb_replace(rb_tree_t *tree, rb_idx_t n_idx, rb_idx_t t_idx); |
| 141 | |
| 142 | /* ...delete node from the tree and return its in-order predecessor/successor */ |
| 143 | extern rb_idx_t rb_delete(rb_tree_t *tree, rb_idx_t n_idx); |
| 144 | |
| 145 | /* ...first in-order item in the tree */ |
| 146 | extern rb_idx_t rb_first(rb_tree_t *tree); |
| 147 | |
| 148 | /* ...last in-order item in the tree */ |
| 149 | extern rb_idx_t rb_last(rb_tree_t *tree); |
| 150 | |
| 151 | /* ...forward tree iterator */ |
| 152 | extern rb_idx_t rb_next(rb_tree_t *tree, rb_idx_t n_idx); |
| 153 | |
| 154 | /* ...backward tree iterator */ |
| 155 | extern rb_idx_t rb_prev(rb_tree_t *tree, rb_idx_t n_idx); |
| 156 | |
| 157 | #endif /* __RBTREE_H */ |