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nuclear@68
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1 #include <stdio.h>
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nuclear@68
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2 #include <stdlib.h>
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nuclear@68
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3 #include <string.h>
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nuclear@68
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4 #include "rbtree.h"
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nuclear@69
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5 #include "panic.h"
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6
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7 #define INT2PTR(x) ((void*)(x))
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nuclear@68
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8 #define PTR2INT(x) ((int)(x))
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9
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nuclear@68
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10 static int cmpaddr(void *ap, void *bp);
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nuclear@68
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11 static int cmpint(void *ap, void *bp);
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12
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13 static int count_nodes(struct rbnode *node);
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14 static void del_tree(struct rbnode *node, void (*delfunc)(struct rbnode*, void*), void *cls);
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nuclear@68
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15 static struct rbnode *insert(struct rbtree *rb, struct rbnode *tree, void *key, void *data);
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16 static struct rbnode *delete(struct rbtree *rb, struct rbnode *tree, void *key);
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nuclear@68
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17 static void traverse(struct rbnode *node, void (*func)(struct rbnode*, void*), void *cls);
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18
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19 struct rbtree *rb_create(rb_cmp_func_t cmp_func)
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20 {
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nuclear@68
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21 struct rbtree *rb;
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22
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23 if(!(rb = malloc(sizeof *rb))) {
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24 return 0;
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25 }
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26 if(rb_init(rb, cmp_func) == -1) {
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27 free(rb);
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28 return 0;
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nuclear@68
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29 }
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nuclear@68
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30 return rb;
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31 }
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32
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nuclear@68
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33 void rb_free(struct rbtree *rb)
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34 {
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35 rb_destroy(rb);
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36 free(rb);
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37 }
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38
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39
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40 int rb_init(struct rbtree *rb, rb_cmp_func_t cmp_func)
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41 {
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42 memset(rb, 0, sizeof *rb);
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43
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nuclear@68
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44 if(cmp_func == RB_KEY_INT) {
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45 rb->cmp = cmpint;
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nuclear@68
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46 } else if(cmp_func == RB_KEY_STRING) {
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47 rb->cmp = (rb_cmp_func_t)strcmp;
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nuclear@68
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48 } else {
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49 rb->cmp = cmpaddr;
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50 }
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51
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52 rb->alloc = malloc;
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53 rb->free = free;
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54 return 0;
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55 }
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56
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nuclear@68
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57 void rb_destroy(struct rbtree *rb)
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58 {
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59 del_tree(rb->root, rb->del, rb->del_cls);
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60 }
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61
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nuclear@69
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62 void rb_clear(struct rbtree *rb)
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nuclear@69
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63 {
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64 del_tree(rb->root, rb->del, rb->del_cls);
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65 rb->root = 0;
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66 }
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67
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68 int rb_copy(struct rbtree *dest, struct rbtree *src)
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69 {
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70 struct rbnode *node;
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71
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72 rb_clear(dest);
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73
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74 rb_begin(src);
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75 while((node = rb_next(src))) {
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76 if(rb_insert(dest, node->key, node->data) == -1) {
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77 return -1;
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nuclear@69
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78 }
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nuclear@69
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79 }
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nuclear@69
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80 return 0;
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nuclear@69
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81 }
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82
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83 void rb_set_allocator(struct rbtree *rb, rb_alloc_func_t alloc, rb_free_func_t free)
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84 {
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85 rb->alloc = alloc;
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86 rb->free = free;
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nuclear@68
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87 }
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88
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89
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90 void rb_set_compare_func(struct rbtree *rb, rb_cmp_func_t func)
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91 {
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92 rb->cmp = func;
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93 }
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94
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95 void rb_set_delete_func(struct rbtree *rb, rb_del_func_t func, void *cls)
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96 {
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97 rb->del = func;
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98 rb->del_cls = cls;
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99 }
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100
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101 int rb_size(struct rbtree *rb)
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102 {
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103 return count_nodes(rb->root);
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104 }
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105
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106 int rb_insert(struct rbtree *rb, void *key, void *data)
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107 {
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108 rb->root = insert(rb, rb->root, key, data);
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109 rb->root->red = 0;
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110 return 0;
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111 }
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112
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113 int rb_inserti(struct rbtree *rb, int key, void *data)
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114 {
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115 rb->root = insert(rb, rb->root, INT2PTR(key), data);
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116 rb->root->red = 0;
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117 return 0;
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118 }
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119
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120
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121 int rb_delete(struct rbtree *rb, void *key)
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122 {
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123 rb->root = delete(rb, rb->root, key);
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124 rb->root->red = 0;
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125 return 0;
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126 }
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127
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128 int rb_deletei(struct rbtree *rb, int key)
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129 {
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130 rb->root = delete(rb, rb->root, INT2PTR(key));
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131 rb->root->red = 0;
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132 return 0;
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133 }
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134
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135
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136 void *rb_find(struct rbtree *rb, void *key)
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137 {
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138 struct rbnode *node = rb->root;
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139
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nuclear@68
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140 while(node) {
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141 int cmp = rb->cmp(key, node->key);
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142 if(cmp == 0) {
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143 return node;
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144 }
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145 node = cmp < 0 ? node->left : node->right;
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nuclear@68
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146 }
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nuclear@68
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147 return 0;
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148 }
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149
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150 void *rb_findi(struct rbtree *rb, int key)
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nuclear@68
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151 {
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152 return rb_find(rb, INT2PTR(key));
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153 }
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154
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155
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156 void rb_foreach(struct rbtree *rb, void (*func)(struct rbnode*, void*), void *cls)
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157 {
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158 traverse(rb->root, func, cls);
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nuclear@68
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159 }
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160
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161
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162 struct rbnode *rb_root(struct rbtree *rb)
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nuclear@68
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163 {
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164 return rb->root;
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nuclear@68
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165 }
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166
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nuclear@68
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167 void rb_begin(struct rbtree *rb)
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168 {
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169 rb->rstack = 0;
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170 rb->iter = rb->root;
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nuclear@68
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171 }
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172
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173 #define push(sp, x) ((x)->next = (sp), (sp) = (x))
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174 #define pop(sp) ((sp) = (sp)->next)
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175 #define top(sp) (sp)
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176
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177 struct rbnode *rb_next(struct rbtree *rb)
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178 {
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179 struct rbnode *res = 0;
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180
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nuclear@68
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181 while(rb->rstack || rb->iter) {
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182 if(rb->iter) {
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183 push(rb->rstack, rb->iter);
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184 rb->iter = rb->iter->left;
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nuclear@68
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185 } else {
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186 rb->iter = top(rb->rstack);
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187 pop(rb->rstack);
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188 res = rb->iter;
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189 rb->iter = rb->iter->right;
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190 break;
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nuclear@68
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191 }
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nuclear@68
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192 }
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nuclear@68
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193 return res;
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194 }
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195
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196 void *rb_node_key(struct rbnode *node)
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197 {
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198 return node ? node->key : 0;
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199 }
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200
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201 int rb_node_keyi(struct rbnode *node)
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nuclear@68
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202 {
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203 return node ? PTR2INT(node->key) : 0;
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204 }
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205
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206 void *rb_node_data(struct rbnode *node)
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207 {
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208 return node ? node->data : 0;
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209 }
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210
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211 static int cmpaddr(void *ap, void *bp)
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212 {
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213 return ap < bp ? -1 : (ap > bp ? 1 : 0);
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214 }
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215
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nuclear@68
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216 static int cmpint(void *ap, void *bp)
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217 {
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218 return PTR2INT(ap) - PTR2INT(bp);
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219 }
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220
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221
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nuclear@68
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222 /* ---- left-leaning 2-3 red-black implementation ---- */
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223
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224 /* helper prototypes */
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225 static int is_red(struct rbnode *tree);
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226 static void color_flip(struct rbnode *tree);
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227 static struct rbnode *rot_left(struct rbnode *a);
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228 static struct rbnode *rot_right(struct rbnode *a);
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229 static struct rbnode *find_min(struct rbnode *tree);
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230 static struct rbnode *del_min(struct rbtree *rb, struct rbnode *tree);
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nuclear@68
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231 /*static struct rbnode *move_red_right(struct rbnode *tree);*/
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232 static struct rbnode *move_red_left(struct rbnode *tree);
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233 static struct rbnode *fix_up(struct rbnode *tree);
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234
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235 static int count_nodes(struct rbnode *node)
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236 {
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nuclear@68
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237 if(!node)
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238 return 0;
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239
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240 return 1 + count_nodes(node->left) + count_nodes(node->right);
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241 }
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242
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nuclear@68
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243 static void del_tree(struct rbnode *node, rb_del_func_t delfunc, void *cls)
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244 {
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nuclear@68
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245 if(!node)
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246 return;
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247
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248 del_tree(node->left, delfunc, cls);
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249 del_tree(node->right, delfunc, cls);
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250
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251 delfunc(node, cls);
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252 free(node);
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nuclear@68
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253 }
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254
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nuclear@68
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255 static struct rbnode *insert(struct rbtree *rb, struct rbnode *tree, void *key, void *data)
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256 {
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257 int cmp;
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258
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nuclear@68
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259 if(!tree) {
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260 struct rbnode *node = rb->alloc(sizeof *node);
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nuclear@69
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261 if(!node) {
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nuclear@69
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262 panic("failed to allocate tree node\n");
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nuclear@69
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263 }
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264 node->red = 1;
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265 node->key = key;
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266 node->data = data;
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267 node->left = node->right = 0;
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268 return node;
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269 }
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270
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271 cmp = rb->cmp(key, tree->key);
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272
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nuclear@68
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273 if(cmp < 0) {
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274 tree->left = insert(rb, tree->left, key, data);
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275 } else if(cmp > 0) {
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276 tree->right = insert(rb, tree->right, key, data);
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277 } else {
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278 tree->data = data;
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nuclear@68
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279 }
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280
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nuclear@68
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281 /* fix right-leaning reds */
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282 if(is_red(tree->right)) {
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283 tree = rot_left(tree);
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nuclear@68
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284 }
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nuclear@68
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285 /* fix two reds in a row */
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286 if(is_red(tree->left) && is_red(tree->left->left)) {
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287 tree = rot_right(tree);
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nuclear@68
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288 }
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289
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nuclear@68
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290 /* if 4-node, split it by color inversion */
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nuclear@68
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291 if(is_red(tree->left) && is_red(tree->right)) {
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nuclear@68
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292 color_flip(tree);
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nuclear@68
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293 }
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294
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295 return tree;
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nuclear@68
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296 }
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nuclear@68
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297
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nuclear@68
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298 static struct rbnode *delete(struct rbtree *rb, struct rbnode *tree, void *key)
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nuclear@68
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299 {
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nuclear@68
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300 int cmp;
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301
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nuclear@68
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302 if(!tree) {
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303 return 0;
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nuclear@68
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304 }
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305
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nuclear@68
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306 cmp = rb->cmp(key, tree->key);
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307
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nuclear@68
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308 if(cmp < 0) {
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nuclear@68
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309 if(!is_red(tree->left) && !is_red(tree->left->left)) {
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nuclear@68
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310 tree = move_red_left(tree);
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nuclear@68
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311 }
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nuclear@68
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312 tree->left = delete(rb, tree->left, key);
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nuclear@68
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313 } else {
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nuclear@68
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314 /* need reds on the right */
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nuclear@68
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315 if(is_red(tree->left)) {
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nuclear@68
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316 tree = rot_right(tree);
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nuclear@68
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317 }
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318
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nuclear@68
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319 /* found it at the bottom (XXX what certifies left is null?) */
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320 if(cmp == 0 && !tree->right) {
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nuclear@68
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321 if(rb->del) {
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nuclear@68
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322 rb->del(tree, rb->del_cls);
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nuclear@68
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323 }
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nuclear@68
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324 rb->free(tree);
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nuclear@68
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325 return 0;
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nuclear@68
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326 }
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nuclear@68
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327
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nuclear@68
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328 if(!is_red(tree->right) && !is_red(tree->right->left)) {
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nuclear@68
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329 tree = move_red_left(tree);
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nuclear@68
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330 }
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nuclear@68
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331
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nuclear@68
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332 if(key == tree->key) {
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333 struct rbnode *rmin = find_min(tree->right);
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nuclear@68
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334 tree->key = rmin->key;
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nuclear@68
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335 tree->data = rmin->data;
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nuclear@68
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336 tree->right = del_min(rb, tree->right);
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nuclear@68
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337 } else {
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nuclear@68
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338 tree->right = delete(rb, tree->right, key);
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nuclear@68
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339 }
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nuclear@68
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340 }
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nuclear@68
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341
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nuclear@68
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342 return fix_up(tree);
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nuclear@68
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343 }
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nuclear@68
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344
|
nuclear@68
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345 /*static struct rbnode *find(struct rbtree *rb, struct rbnode *node, void *key)
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nuclear@68
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346 {
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nuclear@68
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347 int cmp;
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nuclear@68
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348
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nuclear@68
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349 if(!node)
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350 return 0;
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nuclear@68
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351
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nuclear@68
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352 if((cmp = rb->cmp(key, node->key)) == 0) {
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nuclear@68
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353 return node;
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nuclear@68
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354 }
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nuclear@68
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355 return find(rb, cmp < 0 ? node->left : node->right, key);
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nuclear@68
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356 }*/
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357
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nuclear@68
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358 static void traverse(struct rbnode *node, void (*func)(struct rbnode*, void*), void *cls)
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nuclear@68
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359 {
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nuclear@68
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360 if(!node)
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nuclear@68
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361 return;
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nuclear@68
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362
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nuclear@68
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363 traverse(node->left, func, cls);
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nuclear@68
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364 func(node, cls);
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nuclear@68
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365 traverse(node->right, func, cls);
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nuclear@68
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366 }
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nuclear@68
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367
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nuclear@68
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368 /* helpers */
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369
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nuclear@68
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370 static int is_red(struct rbnode *tree)
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nuclear@68
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371 {
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nuclear@68
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372 return tree && tree->red;
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nuclear@68
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373 }
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nuclear@68
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374
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nuclear@68
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375 static void color_flip(struct rbnode *tree)
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nuclear@68
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376 {
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nuclear@68
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377 tree->red = !tree->red;
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nuclear@68
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378 tree->left->red = !tree->left->red;
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nuclear@68
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379 tree->right->red = !tree->right->red;
|
nuclear@68
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380 }
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nuclear@68
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381
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nuclear@68
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382 static struct rbnode *rot_left(struct rbnode *a)
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nuclear@68
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383 {
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nuclear@68
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384 struct rbnode *b = a->right;
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nuclear@68
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385 a->right = b->left;
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nuclear@68
|
386 b->left = a;
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nuclear@68
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387 b->red = a->red;
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nuclear@68
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388 a->red = 1;
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nuclear@68
|
389 return b;
|
nuclear@68
|
390 }
|
nuclear@68
|
391
|
nuclear@68
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392 static struct rbnode *rot_right(struct rbnode *a)
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nuclear@68
|
393 {
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nuclear@68
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394 struct rbnode *b = a->left;
|
nuclear@68
|
395 a->left = b->right;
|
nuclear@68
|
396 b->right = a;
|
nuclear@68
|
397 b->red = a->red;
|
nuclear@68
|
398 a->red = 1;
|
nuclear@68
|
399 return b;
|
nuclear@68
|
400 }
|
nuclear@68
|
401
|
nuclear@68
|
402 static struct rbnode *find_min(struct rbnode *tree)
|
nuclear@68
|
403 {
|
nuclear@68
|
404 struct rbnode *node;
|
nuclear@68
|
405
|
nuclear@68
|
406 if(!tree)
|
nuclear@68
|
407 return 0;
|
nuclear@68
|
408
|
nuclear@68
|
409 while(node->left) {
|
nuclear@68
|
410 node = node->left;
|
nuclear@68
|
411 }
|
nuclear@68
|
412 return node;
|
nuclear@68
|
413 }
|
nuclear@68
|
414
|
nuclear@68
|
415 static struct rbnode *del_min(struct rbtree *rb, struct rbnode *tree)
|
nuclear@68
|
416 {
|
nuclear@68
|
417 if(!tree->left) {
|
nuclear@68
|
418 if(rb->del) {
|
nuclear@68
|
419 rb->del(tree->left, rb->del_cls);
|
nuclear@68
|
420 }
|
nuclear@68
|
421 rb->free(tree->left);
|
nuclear@68
|
422 return 0;
|
nuclear@68
|
423 }
|
nuclear@68
|
424
|
nuclear@68
|
425 /* make sure we've got red (3/4-nodes) at the left side so we can delete at the bottom */
|
nuclear@68
|
426 if(!is_red(tree->left) && !is_red(tree->left->left)) {
|
nuclear@68
|
427 tree = move_red_left(tree);
|
nuclear@68
|
428 }
|
nuclear@68
|
429 tree->left = del_min(rb, tree->left);
|
nuclear@68
|
430
|
nuclear@68
|
431 /* fix right-reds, red-reds, and split 4-nodes on the way up */
|
nuclear@68
|
432 return fix_up(tree);
|
nuclear@68
|
433 }
|
nuclear@68
|
434
|
nuclear@68
|
435 #if 0
|
nuclear@68
|
436 /* push a red link on this node to the right */
|
nuclear@68
|
437 static struct rbnode *move_red_right(struct rbnode *tree)
|
nuclear@68
|
438 {
|
nuclear@68
|
439 /* flipping it makes both children go red, so we have a red to the right */
|
nuclear@68
|
440 color_flip(tree);
|
nuclear@68
|
441
|
nuclear@68
|
442 /* if after the flip we've got a red-red situation to the left, fix it */
|
nuclear@68
|
443 if(is_red(tree->left->left)) {
|
nuclear@68
|
444 tree = rot_right(tree);
|
nuclear@68
|
445 color_flip(tree);
|
nuclear@68
|
446 }
|
nuclear@68
|
447 return tree;
|
nuclear@68
|
448 }
|
nuclear@68
|
449 #endif
|
nuclear@68
|
450
|
nuclear@68
|
451 /* push a red link on this node to the left */
|
nuclear@68
|
452 static struct rbnode *move_red_left(struct rbnode *tree)
|
nuclear@68
|
453 {
|
nuclear@68
|
454 /* flipping it makes both children go red, so we have a red to the left */
|
nuclear@68
|
455 color_flip(tree);
|
nuclear@68
|
456
|
nuclear@68
|
457 /* if after the flip we've got a red-red on the right-left, fix it */
|
nuclear@68
|
458 if(is_red(tree->right->left)) {
|
nuclear@68
|
459 tree->right = rot_right(tree->right);
|
nuclear@68
|
460 tree = rot_left(tree);
|
nuclear@68
|
461 color_flip(tree);
|
nuclear@68
|
462 }
|
nuclear@68
|
463 return tree;
|
nuclear@68
|
464 }
|
nuclear@68
|
465
|
nuclear@68
|
466 static struct rbnode *fix_up(struct rbnode *tree)
|
nuclear@68
|
467 {
|
nuclear@68
|
468 /* fix right-leaning */
|
nuclear@68
|
469 if(is_red(tree->right)) {
|
nuclear@68
|
470 tree = rot_left(tree);
|
nuclear@68
|
471 }
|
nuclear@68
|
472 /* change invalid red-red pairs into a proper 4-node */
|
nuclear@68
|
473 if(is_red(tree->left) && is_red(tree->left->left)) {
|
nuclear@68
|
474 tree = rot_right(tree);
|
nuclear@68
|
475 }
|
nuclear@68
|
476 /* split 4-nodes */
|
nuclear@68
|
477 if(is_red(tree->left) && is_red(tree->right)) {
|
nuclear@68
|
478 color_flip(tree);
|
nuclear@68
|
479 }
|
nuclear@68
|
480 return tree;
|
nuclear@68
|
481 }
|
nuclear@69
|
482
|
nuclear@69
|
483 void rb_dbg_print_tree(struct rbtree *tree)
|
nuclear@69
|
484 {
|
nuclear@69
|
485 struct rbnode *node;
|
nuclear@69
|
486
|
nuclear@69
|
487 rb_begin(tree);
|
nuclear@69
|
488 while((node = rb_next(tree))) {
|
nuclear@69
|
489 printf("%d ", rb_node_keyi(node));
|
nuclear@69
|
490 }
|
nuclear@69
|
491 printf("\n");
|
nuclear@69
|
492 }
|