1 | /** |
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2 | * @file rtems/score/rbtree.inl |
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3 | * |
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4 | * This include file contains the bodies of the routines which are |
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5 | * associated with Red-Black Trees and inlined. |
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6 | * |
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7 | * @note The routines in this file are ordered from simple |
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8 | * to complex. No other RBTree Handler routine is referenced |
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9 | * unless it has already been defined. |
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10 | */ |
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11 | |
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12 | /* |
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13 | * Copyright (c) 2010 Gedare Bloom. |
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14 | * |
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15 | * The license and distribution terms for this file may be |
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16 | * found in the file LICENSE in this distribution or at |
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17 | * http://www.rtems.com/license/LICENSE. |
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18 | * |
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19 | * $Id$ |
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20 | */ |
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21 | |
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22 | #ifndef _RTEMS_SCORE_RBTREE_H |
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23 | # error "Never use <rtems/score/rbtree.inl> directly; include <rtems/score/rbtree.h> instead." |
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24 | #endif |
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25 | |
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26 | #ifndef _RTEMS_SCORE_RBTREE_INL |
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27 | #define _RTEMS_SCORE_RBTREE_INL |
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28 | |
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29 | /** |
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30 | * @addtogroup ScoreRBTree |
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31 | * @{ |
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32 | */ |
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33 | |
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34 | /** |
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35 | * @brief Get the direction opposite to @a the_dir |
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36 | */ |
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37 | RTEMS_INLINE_ROUTINE RBTree_Direction _RBTree_Opposite_direction( |
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38 | RBTree_Direction the_dir |
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39 | ) |
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40 | { |
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41 | return (RBTree_Direction) !((int) the_dir); |
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42 | } |
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43 | |
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44 | /** @brief Set off rbtree |
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45 | * |
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46 | * This function sets the parent and child fields of the @a node to NULL |
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47 | * indicating the @a node is not part of a rbtree. |
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48 | * |
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49 | */ |
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50 | RTEMS_INLINE_ROUTINE void _RBTree_Set_off_rbtree( |
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51 | RBTree_Node *node |
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52 | ) |
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53 | { |
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54 | node->parent = node->child[RBT_LEFT] = node->child[RBT_RIGHT] = NULL; |
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55 | } |
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56 | |
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57 | /** @brief Is the Node off RBTree |
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58 | * |
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59 | * This function returns true if the @a node is not on a rbtree. A @a node is |
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60 | * off rbtree if the parent and child fields are set to NULL. |
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61 | */ |
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62 | RTEMS_INLINE_ROUTINE bool _RBTree_Is_node_off_rbtree( |
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63 | const RBTree_Node *node |
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64 | ) |
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65 | { |
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66 | return (node->parent == NULL) && (node->child[RBT_LEFT] == NULL) && (node->child[RBT_RIGHT] == NULL); |
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67 | } |
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68 | |
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69 | /** @brief Are Two Nodes Equal |
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70 | * |
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71 | * This function returns true if @a left and @a right are equal, |
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72 | * and false otherwise. |
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73 | */ |
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74 | RTEMS_INLINE_ROUTINE bool _RBTree_Are_nodes_equal( |
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75 | const RBTree_Node *left, |
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76 | const RBTree_Node *right |
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77 | ) |
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78 | { |
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79 | return left == right; |
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80 | } |
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81 | |
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82 | /** @brief Is this RBTree Control Pointer Null |
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83 | * |
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84 | * This function returns true if @a the_rbtree is NULL and false otherwise. |
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85 | */ |
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86 | RTEMS_INLINE_ROUTINE bool _RBTree_Is_null( |
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87 | const RBTree_Control *the_rbtree |
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88 | ) |
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89 | { |
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90 | return (the_rbtree == NULL); |
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91 | } |
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92 | |
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93 | /** @brief Is the RBTree Node Pointer NULL |
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94 | * |
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95 | * This function returns true if @a the_node is NULL and false otherwise. |
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96 | */ |
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97 | RTEMS_INLINE_ROUTINE bool _RBTree_Is_null_node( |
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98 | const RBTree_Node *the_node |
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99 | ) |
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100 | { |
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101 | return (the_node == NULL); |
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102 | } |
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103 | |
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104 | |
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105 | /** @brief Return pointer to RBTree's root node |
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106 | * |
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107 | * This function returns a pointer to the root node of @a the_rbtree. |
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108 | */ |
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109 | RTEMS_INLINE_ROUTINE RBTree_Node *_RBTree_Root( |
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110 | const RBTree_Control *the_rbtree |
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111 | ) |
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112 | { |
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113 | return the_rbtree->root; |
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114 | } |
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115 | |
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116 | /** @brief Return pointer to RBTree's First node |
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117 | * |
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118 | * This function returns a pointer to the first node on @a the_rbtree, |
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119 | * where @a dir specifies whether to return the minimum (0) or maximum (1). |
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120 | */ |
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121 | RTEMS_INLINE_ROUTINE RBTree_Node *_RBTree_First( |
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122 | const RBTree_Control *the_rbtree, |
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123 | RBTree_Direction dir |
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124 | ) |
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125 | { |
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126 | return the_rbtree->first[dir]; |
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127 | } |
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128 | |
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129 | /** @brief Return pointer to the parent of this node |
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130 | * |
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131 | * This function returns a pointer to the parent node of @a the_node. |
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132 | */ |
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133 | RTEMS_INLINE_ROUTINE RBTree_Node *_RBTree_Parent( |
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134 | const RBTree_Node *the_node |
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135 | ) |
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136 | { |
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137 | if (!the_node->parent->parent) return NULL; |
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138 | return the_node->parent; |
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139 | } |
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140 | |
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141 | /** @brief Return pointer to the left of this node |
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142 | * |
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143 | * This function returns a pointer to the left node of this node. |
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144 | * |
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145 | * @param[in] the_node is the node to be operated upon. |
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146 | * |
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147 | * @return This method returns the left node on the rbtree. |
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148 | */ |
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149 | RTEMS_INLINE_ROUTINE RBTree_Node *_RBTree_Left( |
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150 | const RBTree_Node *the_node |
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151 | ) |
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152 | { |
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153 | return the_node->child[RBT_LEFT]; |
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154 | } |
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155 | |
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156 | /** @brief Return pointer to the right of this node |
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157 | * |
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158 | * This function returns a pointer to the right node of this node. |
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159 | * |
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160 | * @param[in] the_node is the node to be operated upon. |
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161 | * |
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162 | * @return This method returns the right node on the rbtree. |
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163 | */ |
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164 | RTEMS_INLINE_ROUTINE RBTree_Node *_RBTree_Right( |
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165 | const RBTree_Node *the_node |
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166 | ) |
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167 | { |
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168 | return the_node->child[RBT_RIGHT]; |
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169 | } |
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170 | |
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171 | /** @brief Is the RBTree Empty |
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172 | * |
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173 | * This function returns true if there are no nodes on @a the_rbtree and |
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174 | * false otherwise. |
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175 | * |
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176 | * @param[in] the_rbtree is the rbtree to be operated upon. |
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177 | * |
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178 | * @return This function returns true if there are no nodes on |
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179 | * @a the_rbtree and false otherwise. |
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180 | */ |
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181 | RTEMS_INLINE_ROUTINE bool _RBTree_Is_empty( |
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182 | const RBTree_Control *the_rbtree |
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183 | ) |
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184 | { |
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185 | return (the_rbtree->root == NULL); |
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186 | } |
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187 | |
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188 | /** @brief Is this the First Node on the RBTree |
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189 | * |
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190 | * This function returns true if @a the_node is the first node on |
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191 | * @a the_rbtree and false otherwise. @a dir specifies whether first means |
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192 | * minimum (0) or maximum (1). |
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193 | * |
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194 | */ |
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195 | RTEMS_INLINE_ROUTINE bool _RBTree_Is_first( |
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196 | const RBTree_Control *the_rbtree, |
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197 | const RBTree_Node *the_node, |
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198 | RBTree_Direction dir |
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199 | ) |
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200 | { |
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201 | return (the_node == _RBTree_First(the_rbtree, dir)); |
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202 | } |
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203 | |
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204 | /** @brief Is this node red? |
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205 | * |
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206 | * This function returns true if @a the_node is red and false otherwise. |
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207 | */ |
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208 | RTEMS_INLINE_ROUTINE bool _RBTree_Is_red( |
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209 | const RBTree_Node *the_node |
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210 | ) |
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211 | { |
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212 | return (the_node && the_node->color == RBT_RED); |
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213 | } |
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214 | |
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215 | |
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216 | /** @brief Does this RBTree have only One Node |
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217 | * |
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218 | * This function returns true if there is only one node on @a the_rbtree and |
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219 | * false otherwise. |
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220 | * |
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221 | */ |
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222 | RTEMS_INLINE_ROUTINE bool _RBTree_Has_only_one_node( |
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223 | const RBTree_Control *the_rbtree |
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224 | ) |
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225 | { |
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226 | if(!the_rbtree) return NULL; /* TODO: expected behavior? */ |
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227 | return (the_rbtree->root->child[RBT_LEFT] == NULL && the_rbtree->root->child[RBT_RIGHT] == NULL); |
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228 | } |
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229 | |
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230 | /** @brief Is this Node the RBTree root |
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231 | * |
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232 | * This function returns true if @a the_node is the root of @a the_rbtree and |
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233 | * false otherwise. |
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234 | */ |
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235 | RTEMS_INLINE_ROUTINE bool _RBTree_Is_root( |
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236 | const RBTree_Control *the_rbtree, |
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237 | const RBTree_Node *the_node |
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238 | ) |
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239 | { |
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240 | return (the_node == _RBTree_Root(the_rbtree)); |
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241 | } |
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242 | |
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243 | /** @brief Initialize this RBTree as Empty |
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244 | * |
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245 | * This routine initializes @a the_rbtree to contain zero nodes. |
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246 | */ |
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247 | RTEMS_INLINE_ROUTINE void _RBTree_Initialize_empty( |
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248 | RBTree_Control *the_rbtree, |
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249 | RBTree_Compare_function compare_function, |
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250 | bool is_unique |
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251 | ) |
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252 | { |
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253 | the_rbtree->permanent_null = NULL; |
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254 | the_rbtree->root = NULL; |
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255 | the_rbtree->first[0] = NULL; |
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256 | the_rbtree->first[1] = NULL; |
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257 | the_rbtree->compare_function = compare_function; |
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258 | the_rbtree->is_unique = is_unique; |
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259 | } |
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260 | |
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261 | /** @brief Return a pointer to node's grandparent |
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262 | * |
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263 | * This function returns a pointer to the grandparent of @a the_node if it |
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264 | * exists, and NULL if not. |
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265 | * |
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266 | */ |
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267 | RTEMS_INLINE_ROUTINE RBTree_Node *_RBTree_Grandparent( |
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268 | const RBTree_Node *the_node |
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269 | ) |
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270 | { |
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271 | if(!the_node) return NULL; |
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272 | if(!(the_node->parent)) return NULL; |
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273 | if(!(the_node->parent->parent)) return NULL; |
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274 | if(!(the_node->parent->parent->parent)) return NULL; |
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275 | return(the_node->parent->parent); |
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276 | } |
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277 | |
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278 | /** @brief Return a pointer to node's sibling |
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279 | * |
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280 | * This function returns a pointer to the sibling of @a the_node if it |
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281 | * exists, and NULL if not. |
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282 | */ |
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283 | RTEMS_INLINE_ROUTINE RBTree_Node *_RBTree_Sibling( |
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284 | const RBTree_Node *the_node |
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285 | ) |
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286 | { |
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287 | if(!the_node) return NULL; |
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288 | if(!(the_node->parent)) return NULL; |
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289 | if(!(the_node->parent->parent)) return NULL; |
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290 | |
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291 | if(the_node == the_node->parent->child[RBT_LEFT]) |
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292 | return the_node->parent->child[RBT_RIGHT]; |
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293 | else |
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294 | return the_node->parent->child[RBT_LEFT]; |
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295 | } |
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296 | |
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297 | /** @brief Return a pointer to node's parent's sibling |
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298 | * |
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299 | * This function returns a pointer to the sibling of the parent of |
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300 | * @a the_node if it exists, and NULL if not. |
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301 | */ |
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302 | RTEMS_INLINE_ROUTINE RBTree_Node *_RBTree_Parent_sibling( |
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303 | const RBTree_Node *the_node |
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304 | ) |
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305 | { |
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306 | if(!the_node) return NULL; |
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307 | if(_RBTree_Grandparent(the_node) == NULL) return NULL; |
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308 | |
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309 | return _RBTree_Sibling(the_node->parent); |
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310 | } |
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311 | |
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312 | /** @brief Find the RBTree_Control header given a node in the tree |
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313 | * |
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314 | * This function returns a pointer to the header of the Red Black |
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315 | * Tree containing @a the_node if it exists, and NULL if not. |
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316 | */ |
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317 | RTEMS_INLINE_ROUTINE RBTree_Control *_RBTree_Find_header_unprotected( |
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318 | RBTree_Node *the_node |
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319 | ) |
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320 | { |
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321 | if(!the_node) return NULL; |
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322 | if(!(the_node->parent)) return NULL; |
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323 | while(the_node->parent) the_node = the_node->parent; |
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324 | return (RBTree_Control*)the_node; |
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325 | } |
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326 | |
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327 | RTEMS_INLINE_ROUTINE bool _RBTree_Is_equal( int compare_result ) |
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328 | { |
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329 | return compare_result == 0; |
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330 | } |
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331 | |
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332 | RTEMS_INLINE_ROUTINE bool _RBTree_Is_greater( |
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333 | int compare_result |
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334 | ) |
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335 | { |
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336 | return compare_result > 0; |
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337 | } |
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338 | |
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339 | RTEMS_INLINE_ROUTINE bool _RBTree_Is_lesser( |
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340 | int compare_result |
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341 | ) |
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342 | { |
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343 | return compare_result < 0; |
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344 | } |
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345 | |
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346 | /** @brief Find the node with given key in the tree |
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347 | * |
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348 | * This function returns a pointer to the node in @a the_rbtree |
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349 | * having key equal to key of @a the_node if it exists, |
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350 | * and NULL if not. @a the_node has to be made up before a search. |
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351 | * |
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352 | * @note If the tree is not unique and contains duplicate keys, the set |
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353 | * of duplicate keys acts as FIFO. |
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354 | */ |
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355 | RTEMS_INLINE_ROUTINE RBTree_Node *_RBTree_Find_unprotected( |
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356 | RBTree_Control *the_rbtree, |
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357 | RBTree_Node *the_node |
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358 | ) |
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359 | { |
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360 | RBTree_Node* iter_node = the_rbtree->root; |
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361 | RBTree_Node* found = NULL; |
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362 | int compare_result; |
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363 | while (iter_node) { |
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364 | compare_result = the_rbtree->compare_function(the_node, iter_node); |
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365 | if ( _RBTree_Is_equal( compare_result ) ) { |
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366 | found = iter_node; |
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367 | if ( the_rbtree->is_unique ) |
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368 | break; |
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369 | } |
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370 | |
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371 | RBTree_Direction dir = |
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372 | (RBTree_Direction) _RBTree_Is_greater( compare_result ); |
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373 | iter_node = iter_node->child[dir]; |
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374 | } /* while(iter_node) */ |
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375 | |
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376 | return found; |
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377 | } |
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378 | |
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379 | /** |
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380 | * @brief Returns the predecessor of a node. |
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381 | * |
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382 | * @param[in] rbtree The red-black tree. |
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383 | * @param[in] node The node. |
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384 | * |
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385 | * @retval NULL The predecessor does not exist. |
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386 | * @retval otherwise The predecessor node. |
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387 | */ |
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388 | RTEMS_INLINE_ROUTINE RBTree_Node *_RBTree_Predecessor_unprotected( |
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389 | const RBTree_Control *rbtree, |
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390 | const RBTree_Node *node |
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391 | ) |
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392 | { |
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393 | return _RBTree_Next_unprotected( rbtree, node, RBT_LEFT ); |
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394 | } |
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395 | |
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396 | /** |
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397 | * @copydoc _RBTree_Predecessor_unprotected() |
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398 | * |
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399 | * The function disables the interrupts protect the operation. |
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400 | */ |
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401 | RTEMS_INLINE_ROUTINE RBTree_Node *_RBTree_Predecessor( |
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402 | const RBTree_Control *rbtree, |
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403 | const RBTree_Node *node |
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404 | ) |
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405 | { |
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406 | return _RBTree_Next( rbtree, node, RBT_LEFT ); |
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407 | } |
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408 | |
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409 | /** |
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410 | * @brief Returns the successor of a node. |
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411 | * |
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412 | * @param[in] rbtree The red-black tree. |
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413 | * @param[in] node The node. |
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414 | * |
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415 | * @retval NULL The successor does not exist. |
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416 | * @retval otherwise The successor node. |
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417 | */ |
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418 | RTEMS_INLINE_ROUTINE RBTree_Node *_RBTree_Successor_unprotected( |
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419 | const RBTree_Control *rbtree, |
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420 | const RBTree_Node *node |
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421 | ) |
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422 | { |
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423 | return _RBTree_Next_unprotected( rbtree, node, RBT_RIGHT ); |
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424 | } |
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425 | |
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426 | /** |
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427 | * @copydoc _RBTree_Successor_unprotected() |
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428 | * |
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429 | * The function disables the interrupts protect the operation. |
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430 | */ |
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431 | RTEMS_INLINE_ROUTINE RBTree_Node *_RBTree_Successor( |
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432 | const RBTree_Control *rbtree, |
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433 | const RBTree_Node *node |
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434 | ) |
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435 | { |
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436 | return _RBTree_Next( rbtree, node, RBT_RIGHT ); |
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437 | } |
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438 | |
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439 | /** @brief Get the First Node (unprotected) |
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440 | * |
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441 | * This function removes the minimum or maximum node from the_rbtree and |
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442 | * returns a pointer to that node. It does NOT disable interrupts to ensure |
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443 | * the atomicity of the get operation. |
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444 | * |
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445 | * @param[in] the_rbtree is the rbtree to attempt to get the min node from. |
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446 | * @param[in] dir specifies whether to get minimum (0) or maximum (1) |
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447 | * |
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448 | * @return This method returns the min or max node on the rbtree, or NULL. |
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449 | * |
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450 | * @note This routine may return NULL if the RBTree is empty. |
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451 | */ |
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452 | RTEMS_INLINE_ROUTINE RBTree_Node *_RBTree_Get_unprotected( |
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453 | RBTree_Control *the_rbtree, |
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454 | RBTree_Direction dir |
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455 | ) |
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456 | { |
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457 | RBTree_Node *the_node = the_rbtree->first[dir]; |
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458 | _RBTree_Extract_unprotected(the_rbtree, the_node); |
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459 | return the_node; |
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460 | } |
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461 | |
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462 | /** @brief Peek at the First Node (unprotected) |
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463 | * |
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464 | * This function returns a pointer to the first node, minimum if @a dir is 0 |
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465 | * or maximum if @a dir is 1, from @a the_rbtree without extracting it. |
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466 | * It does NOT disable interrupts to ensure the atomicity of the peek. |
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467 | * |
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468 | * @retval NULL if @a the_rbtree is empty. |
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469 | */ |
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470 | RTEMS_INLINE_ROUTINE RBTree_Node *_RBTree_Peek_unprotected( |
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471 | const RBTree_Control *the_rbtree, |
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472 | RBTree_Direction dir |
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473 | ) |
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474 | { |
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475 | return(the_rbtree->first[dir]); |
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476 | } |
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477 | |
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478 | /** @brief Rotate the_node in the direction passed as second argument |
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479 | * |
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480 | * This routine rotates @a the_node to the direction @a dir, swapping |
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481 | * @a the_node with its child\[@a dir\]. |
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482 | */ |
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483 | RTEMS_INLINE_ROUTINE void _RBTree_Rotate( |
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484 | RBTree_Node *the_node, |
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485 | RBTree_Direction dir |
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486 | ) |
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487 | { |
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488 | RBTree_Node *c; |
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489 | if (the_node == NULL) return; |
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490 | if (the_node->child[_RBTree_Opposite_direction(dir)] == NULL) return; |
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491 | |
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492 | c = the_node->child[_RBTree_Opposite_direction(dir)]; |
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493 | the_node->child[_RBTree_Opposite_direction(dir)] = c->child[dir]; |
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494 | |
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495 | if (c->child[dir]) |
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496 | c->child[dir]->parent = the_node; |
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497 | |
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498 | c->child[dir] = the_node; |
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499 | |
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500 | the_node->parent->child[the_node != the_node->parent->child[0]] = c; |
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501 | |
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502 | c->parent = the_node->parent; |
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503 | the_node->parent = c; |
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504 | } |
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505 | |
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506 | /** @brief Determines whether the tree is unique |
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507 | */ |
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508 | RTEMS_INLINE_ROUTINE bool _RBTree_Is_unique( |
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509 | const RBTree_Control *the_rbtree |
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510 | ) |
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511 | { |
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512 | return( the_rbtree && the_rbtree->is_unique ); |
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513 | } |
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514 | /**@}*/ |
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515 | |
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516 | #endif |
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517 | /* end of include file */ |
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