[93fb3cb0] | 1 | /** |
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| 2 | * @file |
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| 3 | * |
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| 4 | * @brief Inlined Routines Associated with Red-Black Trees |
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| 5 | * |
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| 6 | * This include file contains the bodies of the routines which are |
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| 7 | * associated with Red-Black Trees and inlined. |
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| 8 | * |
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| 9 | * @note The routines in this file are ordered from simple |
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| 10 | * to complex. No other RBTree Handler routine is referenced |
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| 11 | * unless it has already been defined. |
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| 12 | */ |
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| 13 | |
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| 14 | /* |
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| 15 | * Copyright (c) 2010-2012 Gedare Bloom. |
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| 16 | * |
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| 17 | * The license and distribution terms for this file may be |
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| 18 | * found in the file LICENSE in this distribution or at |
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[c499856] | 19 | * http://www.rtems.org/license/LICENSE. |
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[93fb3cb0] | 20 | */ |
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| 21 | |
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| 22 | #ifndef _RTEMS_SCORE_RBTREEIMPL_H |
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| 23 | #define _RTEMS_SCORE_RBTREEIMPL_H |
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| 24 | |
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| 25 | #include <rtems/score/rbtree.h> |
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| 26 | |
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| 27 | #ifdef __cplusplus |
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| 28 | extern "C" { |
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| 29 | #endif |
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| 30 | |
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| 31 | /** |
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| 32 | * @addtogroup ScoreRBTree |
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| 33 | */ |
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| 34 | /**@{**/ |
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| 35 | |
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| 36 | /** |
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| 37 | * @brief Red-black tree visitor. |
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| 38 | * |
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| 39 | * @param[in] node The node. |
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| 40 | * @param[in] dir The direction. |
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| 41 | * @param[in] visitor_arg The visitor argument. |
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| 42 | * |
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| 43 | * @retval true Stop the iteration. |
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| 44 | * @retval false Continue the iteration. |
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| 45 | * |
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[4ea97d24] | 46 | * @see _RBTree_Iterate(). |
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[93fb3cb0] | 47 | */ |
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| 48 | typedef bool (*RBTree_Visitor)( |
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| 49 | const RBTree_Node *node, |
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| 50 | RBTree_Direction dir, |
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| 51 | void *visitor_arg |
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| 52 | ); |
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| 53 | |
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| 54 | /** |
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| 55 | * @brief Red-black tree iteration. |
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| 56 | * |
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| 57 | * @param[in] rbtree The red-black tree. |
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| 58 | * @param[in] dir The direction. |
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| 59 | * @param[in] visitor The visitor. |
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| 60 | * @param[in] visitor_arg The visitor argument. |
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| 61 | */ |
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[4ea97d24] | 62 | void _RBTree_Iterate( |
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[93fb3cb0] | 63 | const RBTree_Control *rbtree, |
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| 64 | RBTree_Direction dir, |
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| 65 | RBTree_Visitor visitor, |
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| 66 | void *visitor_arg |
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| 67 | ); |
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| 68 | |
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| 69 | /** |
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| 70 | * @brief Get the direction opposite to @a the_dir. |
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| 71 | */ |
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| 72 | RTEMS_INLINE_ROUTINE RBTree_Direction _RBTree_Opposite_direction( |
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| 73 | RBTree_Direction the_dir |
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| 74 | ) |
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| 75 | { |
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| 76 | return (RBTree_Direction) !((int) the_dir); |
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| 77 | } |
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| 78 | |
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[4752550f] | 79 | /** |
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| 80 | * @brief Returns the direction of the node. |
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| 81 | * |
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| 82 | * @param[in] the_node The node of interest. |
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| 83 | * @param[in] parent The parent of the node. The parent must exist, thus it is |
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| 84 | * invalid to use this function for the root node. |
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| 85 | */ |
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| 86 | RTEMS_INLINE_ROUTINE RBTree_Direction _RBTree_Direction( |
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| 87 | const RBTree_Node *the_node, |
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| 88 | const RBTree_Node *parent |
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| 89 | ) |
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| 90 | { |
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| 91 | return (RBTree_Direction) ( the_node != parent->child[ 0 ] ); |
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| 92 | } |
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| 93 | |
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[93fb3cb0] | 94 | /** |
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| 95 | * @brief Is this node red. |
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| 96 | * |
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| 97 | * This function returns true if @a the_node is red and false otherwise. |
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| 98 | * |
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| 99 | * @retval true @a the_node is red. |
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| 100 | * @retval false @a the_node in not red. |
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| 101 | */ |
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| 102 | RTEMS_INLINE_ROUTINE bool _RBTree_Is_red( |
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| 103 | const RBTree_Node *the_node |
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| 104 | ) |
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| 105 | { |
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| 106 | return (the_node && the_node->color == RBT_RED); |
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| 107 | } |
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| 108 | |
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| 109 | /** |
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| 110 | * @brief Return a pointer to node's grandparent. |
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| 111 | * |
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| 112 | * This function returns a pointer to the grandparent of @a the_node if it |
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| 113 | * exists, and NULL if not. |
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| 114 | */ |
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| 115 | RTEMS_INLINE_ROUTINE RBTree_Node *_RBTree_Grandparent( |
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| 116 | const RBTree_Node *the_node |
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| 117 | ) |
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| 118 | { |
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| 119 | if(!the_node) return NULL; |
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| 120 | if(!(the_node->parent)) return NULL; |
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| 121 | if(!(the_node->parent->parent)) return NULL; |
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| 122 | if(!(the_node->parent->parent->parent)) return NULL; |
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| 123 | return(the_node->parent->parent); |
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| 124 | } |
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| 125 | |
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| 126 | /** |
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| 127 | * @brief Return a pointer to node's sibling. |
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| 128 | * |
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| 129 | * This function returns a pointer to the sibling of @a the_node if it |
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| 130 | * exists, and NULL if not. |
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| 131 | */ |
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| 132 | RTEMS_INLINE_ROUTINE RBTree_Node *_RBTree_Sibling( |
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| 133 | const RBTree_Node *the_node |
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| 134 | ) |
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| 135 | { |
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| 136 | if(!the_node) return NULL; |
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| 137 | if(!(the_node->parent)) return NULL; |
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| 138 | if(!(the_node->parent->parent)) return NULL; |
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| 139 | |
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| 140 | if(the_node == the_node->parent->child[RBT_LEFT]) |
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| 141 | return the_node->parent->child[RBT_RIGHT]; |
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| 142 | else |
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| 143 | return the_node->parent->child[RBT_LEFT]; |
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| 144 | } |
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| 145 | |
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| 146 | /** |
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| 147 | * @brief Return a pointer to node's parent's sibling. |
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| 148 | * |
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| 149 | * This function returns a pointer to the sibling of the parent of |
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| 150 | * @a the_node if it exists, and NULL if not. |
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| 151 | */ |
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| 152 | RTEMS_INLINE_ROUTINE RBTree_Node *_RBTree_Parent_sibling( |
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| 153 | const RBTree_Node *the_node |
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| 154 | ) |
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| 155 | { |
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| 156 | if(!the_node) return NULL; |
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| 157 | if(_RBTree_Grandparent(the_node) == NULL) return NULL; |
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| 158 | |
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| 159 | return _RBTree_Sibling(the_node->parent); |
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| 160 | } |
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| 161 | |
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[60fe374] | 162 | RTEMS_INLINE_ROUTINE bool _RBTree_Is_equal( |
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| 163 | RBTree_Compare_result compare_result |
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| 164 | ) |
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[93fb3cb0] | 165 | { |
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| 166 | return compare_result == 0; |
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| 167 | } |
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| 168 | |
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| 169 | RTEMS_INLINE_ROUTINE bool _RBTree_Is_greater( |
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[60fe374] | 170 | RBTree_Compare_result compare_result |
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[93fb3cb0] | 171 | ) |
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| 172 | { |
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| 173 | return compare_result > 0; |
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| 174 | } |
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| 175 | |
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| 176 | RTEMS_INLINE_ROUTINE bool _RBTree_Is_lesser( |
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[60fe374] | 177 | RBTree_Compare_result compare_result |
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[93fb3cb0] | 178 | ) |
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| 179 | { |
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| 180 | return compare_result < 0; |
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| 181 | } |
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| 182 | |
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| 183 | /** |
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[4752550f] | 184 | * @brief Rotates the node in the specified direction. |
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[93fb3cb0] | 185 | * |
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[4752550f] | 186 | * The node is swapped with its child in the opposite direction if it exists. |
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| 187 | * |
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| 188 | * Sub-tree before rotation: |
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| 189 | * @dot |
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| 190 | * digraph state { |
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| 191 | * parent -> the_node; |
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| 192 | * the_node -> sibling [label="dir"]; |
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| 193 | * the_node -> child [label="opp_dir"]; |
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| 194 | * child -> grandchild [label="dir"]; |
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| 195 | * child -> grandchildsibling [label="opp_dir"]; |
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| 196 | * } |
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| 197 | * @enddot |
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| 198 | * |
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| 199 | * Sub-tree after rotation: |
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| 200 | * @dot |
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| 201 | * digraph state { |
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| 202 | * parent -> child; |
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| 203 | * the_node -> sibling [label="dir"]; |
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| 204 | * the_node -> grandchild [label="opp_dir"]; |
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| 205 | * child -> the_node [label="dir"]; |
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| 206 | * child -> grandchildsibling [label="opp_dir"]; |
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| 207 | * } |
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| 208 | * @enddot |
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| 209 | * |
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| 210 | * @param[in] the_node The node to rotate. |
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| 211 | * @param[in] dir The rotation direction. |
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[93fb3cb0] | 212 | */ |
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| 213 | RTEMS_INLINE_ROUTINE void _RBTree_Rotate( |
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[4752550f] | 214 | RBTree_Node *the_node, |
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| 215 | RBTree_Direction dir |
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| 216 | ) |
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[93fb3cb0] | 217 | { |
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[4752550f] | 218 | RBTree_Direction opp_dir = _RBTree_Opposite_direction( dir ); |
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| 219 | RBTree_Node *child = the_node->child[ opp_dir ]; |
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| 220 | RBTree_Node *grandchild; |
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| 221 | RBTree_Node *parent; |
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| 222 | |
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| 223 | if ( child == NULL) |
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| 224 | return; |
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[93fb3cb0] | 225 | |
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[4752550f] | 226 | grandchild = child->child[ dir ]; |
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| 227 | the_node->child[ opp_dir ] = grandchild; |
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[93fb3cb0] | 228 | |
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[4752550f] | 229 | if ( grandchild != NULL ) |
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| 230 | grandchild->parent = the_node; |
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[93fb3cb0] | 231 | |
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[4752550f] | 232 | child->child[ dir ] = the_node; |
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[93fb3cb0] | 233 | |
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[4752550f] | 234 | parent = _RBTree_Parent( the_node ); |
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| 235 | parent->child[ _RBTree_Direction( the_node, parent ) ] = child; |
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[93fb3cb0] | 236 | |
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[4752550f] | 237 | child->parent = parent; |
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| 238 | the_node->parent = child; |
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[93fb3cb0] | 239 | } |
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| 240 | |
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| 241 | /** @} */ |
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| 242 | |
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| 243 | #ifdef __cplusplus |
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| 244 | } |
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| 245 | #endif |
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| 246 | |
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| 247 | #endif |
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| 248 | /* end of include file */ |
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