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111
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1 /* A typesafe wrapper around libiberty's splay-tree.h.
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145
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2 Copyright (C) 2015-2020 Free Software Foundation, Inc.
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111
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3
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4 This file is part of GCC.
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5
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6 GCC is free software; you can redistribute it and/or modify it under
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7 the terms of the GNU General Public License as published by the Free
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8 Software Foundation; either version 3, or (at your option) any later
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9 version.
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10
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11 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
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12 WARRANTY; without even the implied warranty of MERCHANTABILITY or
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13 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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14 for more details.
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15
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16 You should have received a copy of the GNU General Public License
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17 along with GCC; see the file COPYING3. If not see
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18 <http://www.gnu.org/licenses/>. */
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19
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20 #ifndef GCC_TYPED_SPLAY_TREE_H
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21 #define GCC_TYPED_SPLAY_TREE_H
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22
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23 /* Typesafe wrapper around libiberty's splay-tree.h. */
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24 template <typename KEY_TYPE, typename VALUE_TYPE>
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25 class typed_splay_tree
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26 {
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27 public:
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28 typedef KEY_TYPE key_type;
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29 typedef VALUE_TYPE value_type;
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30
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31 typedef int (*compare_fn) (key_type, key_type);
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32 typedef void (*delete_key_fn) (key_type);
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33 typedef void (*delete_value_fn) (value_type);
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34 typedef int (*foreach_fn) (key_type, value_type, void *);
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35
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36 typed_splay_tree (compare_fn,
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37 delete_key_fn,
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38 delete_value_fn);
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39 ~typed_splay_tree ();
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40
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41 value_type lookup (key_type k);
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42 value_type predecessor (key_type k);
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43 value_type successor (key_type k);
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44 void insert (key_type k, value_type v);
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131
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45 void remove (key_type k);
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46 value_type max ();
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47 value_type min ();
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48 int foreach (foreach_fn, void *);
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49
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50 private:
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131
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51 /* Copy and assignment ops are not supported. */
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52 typed_splay_tree (const typed_splay_tree &);
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53 typed_splay_tree & operator = (const typed_splay_tree &);
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54
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55 typedef key_type splay_tree_key;
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56 typedef value_type splay_tree_value;
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57
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58 /* The nodes in the splay tree. */
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59 struct splay_tree_node_s {
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60 /* The key. */
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61 splay_tree_key key;
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62
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63 /* The value. */
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64 splay_tree_value value;
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65
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66 /* The left and right children, respectively. */
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67 splay_tree_node_s *left, *right;
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68
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69 /* Used as temporary value for tree traversals. */
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70 splay_tree_node_s *back;
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71 };
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72 typedef splay_tree_node_s *splay_tree_node;
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73
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131
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74 inline void KDEL (splay_tree_key);
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75 inline void VDEL (splay_tree_value);
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76 void splay_tree_delete_helper (splay_tree_node);
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77 static inline void rotate_left (splay_tree_node *,
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78 splay_tree_node, splay_tree_node);
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79 static inline void rotate_right (splay_tree_node *,
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80 splay_tree_node, splay_tree_node);
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81 void splay_tree_splay (splay_tree_key);
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82 static int splay_tree_foreach_helper (splay_tree_node,
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83 foreach_fn, void*);
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84 splay_tree_node splay_tree_insert (splay_tree_key, splay_tree_value);
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85 void splay_tree_remove (splay_tree_key key);
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86 splay_tree_node splay_tree_lookup (splay_tree_key key);
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87 splay_tree_node splay_tree_predecessor (splay_tree_key);
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88 splay_tree_node splay_tree_successor (splay_tree_key);
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89 splay_tree_node splay_tree_max ();
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90 splay_tree_node splay_tree_min ();
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91
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92 static value_type node_to_value (splay_tree_node node);
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93
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131
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94 /* The root of the tree. */
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95 splay_tree_node root;
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96
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97 /* The comparision function. */
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98 compare_fn comp;
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99
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100 /* The deallocate-key function. NULL if no cleanup is necessary. */
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101 delete_key_fn delete_key;
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102
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103 /* The deallocate-value function. NULL if no cleanup is necessary. */
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104 delete_value_fn delete_value;
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105 };
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106
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107 /* Constructor for typed_splay_tree <K, V>. */
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108
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109 template <typename KEY_TYPE, typename VALUE_TYPE>
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110 inline typed_splay_tree<KEY_TYPE, VALUE_TYPE>::
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111 typed_splay_tree (compare_fn compare_fn,
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112 delete_key_fn delete_key_fn,
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113 delete_value_fn delete_value_fn)
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114 {
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131
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115 root = NULL;
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116 comp = compare_fn;
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117 delete_key = delete_key_fn;
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118 delete_value = delete_value_fn;
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111
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119 }
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120
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121 /* Destructor for typed_splay_tree <K, V>. */
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122
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123 template <typename KEY_TYPE, typename VALUE_TYPE>
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124 inline typed_splay_tree<KEY_TYPE, VALUE_TYPE>::
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125 ~typed_splay_tree ()
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126 {
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131
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127 splay_tree_delete_helper (root);
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128 }
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129
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130 /* Lookup KEY, returning a value if present, and NULL
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131 otherwise. */
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132
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133 template <typename KEY_TYPE, typename VALUE_TYPE>
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134 inline VALUE_TYPE
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135 typed_splay_tree<KEY_TYPE, VALUE_TYPE>::lookup (key_type key)
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136 {
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137 splay_tree_node node = splay_tree_lookup (key);
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138 return node_to_value (node);
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139 }
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140
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141 /* Return the immediate predecessor of KEY, or NULL if there is no
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142 predecessor. KEY need not be present in the tree. */
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143
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144 template <typename KEY_TYPE, typename VALUE_TYPE>
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145 inline VALUE_TYPE
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146 typed_splay_tree<KEY_TYPE, VALUE_TYPE>::predecessor (key_type key)
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147 {
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148 splay_tree_node node = splay_tree_predecessor (key);
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149 return node_to_value (node);
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150 }
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151
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152 /* Return the immediate successor of KEY, or NULL if there is no
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153 successor. KEY need not be present in the tree. */
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154
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155 template <typename KEY_TYPE, typename VALUE_TYPE>
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156 inline VALUE_TYPE
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157 typed_splay_tree<KEY_TYPE, VALUE_TYPE>::successor (key_type key)
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158 {
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159 splay_tree_node node = splay_tree_successor (key);
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160 return node_to_value (node);
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161 }
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162
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163 /* Insert a new node (associating KEY with VALUE). If a
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164 previous node with the indicated KEY exists, its data is replaced
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165 with the new value. */
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166
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167 template <typename KEY_TYPE, typename VALUE_TYPE>
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168 inline void
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169 typed_splay_tree<KEY_TYPE, VALUE_TYPE>::insert (key_type key,
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170 value_type value)
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171 {
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172 splay_tree_insert (key, value);
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173 }
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174
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175 /* Remove a node (associating KEY with VALUE). */
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176
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177 template <typename KEY_TYPE, typename VALUE_TYPE>
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178 inline void
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179 typed_splay_tree<KEY_TYPE, VALUE_TYPE>::remove (key_type key)
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180 {
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181 splay_tree_remove (key);
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182 }
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183
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184 /* Get the value with maximal key. */
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185
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186 template <typename KEY_TYPE, typename VALUE_TYPE>
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187 inline VALUE_TYPE
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188 typed_splay_tree<KEY_TYPE, VALUE_TYPE>::max ()
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189 {
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190 return node_to_value (splay_tree_max ());
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191 }
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192
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193 /* Get the value with minimal key. */
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194
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195 template <typename KEY_TYPE, typename VALUE_TYPE>
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196 inline VALUE_TYPE
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197 typed_splay_tree<KEY_TYPE, VALUE_TYPE>::min ()
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198 {
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199 return node_to_value (splay_tree_min ());
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200 }
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201
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202 /* Call OUTER_CB, passing it the OUTER_USER_DATA, for every node,
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203 following an in-order traversal. If OUTER_CB ever returns a non-zero
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204 value, the iteration ceases immediately, and the value is returned.
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205 Otherwise, this function returns 0. */
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206
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207 template <typename KEY_TYPE, typename VALUE_TYPE>
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208 inline int
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209 typed_splay_tree<KEY_TYPE, VALUE_TYPE>::foreach (foreach_fn foreach_fn,
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210 void *user_data)
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211 {
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212 return splay_tree_foreach_helper (root, foreach_fn, user_data);
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213 }
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214
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215 /* Internal function for converting from splay_tree_node to
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216 VALUE_TYPE. */
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217 template <typename KEY_TYPE, typename VALUE_TYPE>
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218 inline VALUE_TYPE
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219 typed_splay_tree<KEY_TYPE, VALUE_TYPE>::node_to_value (splay_tree_node node)
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220 {
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221 if (node)
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222 return node->value;
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223 else
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224 return 0;
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225 }
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226
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131
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227 template <typename KEY_TYPE, typename VALUE_TYPE>
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228 inline void
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229 typed_splay_tree<KEY_TYPE, VALUE_TYPE>::KDEL(splay_tree_key x)
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230 {
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231 if (delete_key)
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232 (*delete_key)(x);
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233 }
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234
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235 template <typename KEY_TYPE, typename VALUE_TYPE>
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236 inline void
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237 typed_splay_tree<KEY_TYPE, VALUE_TYPE>::VDEL(splay_tree_value x)
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238 {
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239 if (delete_value)
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240 (*delete_value)(x);
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241 }
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242
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243 /* Deallocate NODE (a member of SP), and all its sub-trees. */
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244
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245 template <typename KEY_TYPE, typename VALUE_TYPE>
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246 void
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247 typed_splay_tree<KEY_TYPE,
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248 VALUE_TYPE>::splay_tree_delete_helper (splay_tree_node node)
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249 {
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250 splay_tree_node pending = NULL;
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251 splay_tree_node active = NULL;
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252
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253 if (!node)
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254 return;
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255
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256 KDEL (node->key);
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257 VDEL (node->value);
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258
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259 /* We use the "back" field to hold the "next" pointer. */
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260 node->back = pending;
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261 pending = node;
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262
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263 /* Now, keep processing the pending list until there aren't any
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264 more. This is a little more complicated than just recursing, but
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265 it doesn't toast the stack for large trees. */
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266
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267 while (pending)
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268 {
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269 active = pending;
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270 pending = NULL;
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271 while (active)
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272 {
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273 splay_tree_node temp;
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274
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275 /* active points to a node which has its key and value
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276 deallocated, we just need to process left and right. */
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277
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278 if (active->left)
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279 {
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280 KDEL (active->left->key);
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281 VDEL (active->left->value);
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282 active->left->back = pending;
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283 pending = active->left;
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284 }
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285 if (active->right)
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286 {
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287 KDEL (active->right->key);
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288 VDEL (active->right->value);
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289 active->right->back = pending;
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290 pending = active->right;
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291 }
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292
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293 temp = active;
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294 active = temp->back;
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295 delete temp;
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296 }
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297 }
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298 }
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299
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300 /* Rotate the edge joining the left child N with its parent P. PP is the
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301 grandparents' pointer to P. */
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302
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303 template <typename KEY_TYPE, typename VALUE_TYPE>
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304 inline void
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305 typed_splay_tree<KEY_TYPE, VALUE_TYPE>::rotate_left (splay_tree_node *pp,
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306 splay_tree_node p,
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307 splay_tree_node n)
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308 {
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309 splay_tree_node tmp;
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310 tmp = n->right;
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311 n->right = p;
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312 p->left = tmp;
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313 *pp = n;
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314 }
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315
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316 /* Rotate the edge joining the right child N with its parent P. PP is the
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317 grandparents' pointer to P. */
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318
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319 template <typename KEY_TYPE, typename VALUE_TYPE>
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320 inline void
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321 typed_splay_tree<KEY_TYPE, VALUE_TYPE>::rotate_right (splay_tree_node *pp,
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322 splay_tree_node p,
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323 splay_tree_node n)
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324 {
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325 splay_tree_node tmp;
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326 tmp = n->left;
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327 n->left = p;
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328 p->right = tmp;
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329 *pp = n;
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330 }
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331
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332 /* Bottom up splay of key. */
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333
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334 template <typename KEY_TYPE, typename VALUE_TYPE>
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335 void
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336 typed_splay_tree<KEY_TYPE, VALUE_TYPE>::splay_tree_splay (splay_tree_key key)
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337 {
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338 if (root == NULL)
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339 return;
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340
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341 do {
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342 int cmp1, cmp2;
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343 splay_tree_node n, c;
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344
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345 n = root;
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346 cmp1 = (*comp) (key, n->key);
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347
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348 /* Found. */
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349 if (cmp1 == 0)
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350 return;
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351
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352 /* Left or right? If no child, then we're done. */
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353 if (cmp1 < 0)
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354 c = n->left;
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355 else
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356 c = n->right;
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357 if (!c)
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358 return;
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359
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360 /* Next one left or right? If found or no child, we're done
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361 after one rotation. */
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362 cmp2 = (*comp) (key, c->key);
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363 if (cmp2 == 0
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364 || (cmp2 < 0 && !c->left)
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365 || (cmp2 > 0 && !c->right))
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366 {
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367 if (cmp1 < 0)
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368 rotate_left (&root, n, c);
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369 else
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370 rotate_right (&root, n, c);
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371 return;
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372 }
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373
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374 /* Now we have the four cases of double-rotation. */
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375 if (cmp1 < 0 && cmp2 < 0)
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376 {
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377 rotate_left (&n->left, c, c->left);
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378 rotate_left (&root, n, n->left);
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379 }
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380 else if (cmp1 > 0 && cmp2 > 0)
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381 {
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382 rotate_right (&n->right, c, c->right);
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383 rotate_right (&root, n, n->right);
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384 }
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385 else if (cmp1 < 0 && cmp2 > 0)
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386 {
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387 rotate_right (&n->left, c, c->right);
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388 rotate_left (&root, n, n->left);
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389 }
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390 else if (cmp1 > 0 && cmp2 < 0)
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391 {
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392 rotate_left (&n->right, c, c->left);
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393 rotate_right (&root, n, n->right);
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394 }
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395 } while (1);
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396 }
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397
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398 /* Call FN, passing it the DATA, for every node below NODE, all of
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399 which are from SP, following an in-order traversal. If FN every
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400 returns a non-zero value, the iteration ceases immediately, and the
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401 value is returned. Otherwise, this function returns 0. */
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402
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403 template <typename KEY_TYPE, typename VALUE_TYPE>
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404 int
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405 typed_splay_tree<KEY_TYPE, VALUE_TYPE>::splay_tree_foreach_helper (
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406 splay_tree_node node,
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407 foreach_fn fn, void *data)
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408 {
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409 int val;
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410 splay_tree_node stack;
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411
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412 /* A non-recursive implementation is used to avoid filling the stack
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413 for large trees. Splay trees are worst case O(n) in the depth of
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414 the tree. */
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415
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416 stack = NULL;
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417 val = 0;
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418
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419 for (;;)
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420 {
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421 while (node != NULL)
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422 {
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423 node->back = stack;
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424 stack = node;
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425 node = node->left;
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426 }
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427
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428 if (stack == NULL)
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429 break;
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430
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431 node = stack;
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432 stack = stack->back;
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433
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434 val = (*fn) (node->key, node->value, data);
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435 if (val)
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436 break;
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437
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438 node = node->right;
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439 }
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440
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441 return val;
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442 }
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443
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444 /* Insert a new node (associating KEY with DATA) into SP. If a
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445 previous node with the indicated KEY exists, its data is replaced
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446 with the new value. Returns the new node. */
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447
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448 template <typename KEY_TYPE, typename VALUE_TYPE>
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449 typename typed_splay_tree<KEY_TYPE, VALUE_TYPE>::splay_tree_node
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450 typed_splay_tree<KEY_TYPE, VALUE_TYPE>::splay_tree_insert (
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451 splay_tree_key key,
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452 splay_tree_value value)
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453 {
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454 int comparison = 0;
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455
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456 splay_tree_splay (key);
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457
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458 if (root)
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459 comparison = (*comp)(root->key, key);
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460
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461 if (root && comparison == 0)
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462 {
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463 /* If the root of the tree already has the indicated KEY, just
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464 replace the value with VALUE. */
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465 VDEL(root->value);
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466 root->value = value;
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467 }
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468 else
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469 {
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470 /* Create a new node, and insert it at the root. */
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471 splay_tree_node node;
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472
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473 node = new splay_tree_node_s;
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474 node->key = key;
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475 node->value = value;
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476
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477 if (!root)
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478 node->left = node->right = 0;
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479 else if (comparison < 0)
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480 {
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481 node->left = root;
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482 node->right = node->left->right;
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|
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483 node->left->right = 0;
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484 }
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485 else
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486 {
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487 node->right = root;
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488 node->left = node->right->left;
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489 node->right->left = 0;
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490 }
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491
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492 root = node;
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493 }
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494
|
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495 return root;
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496 }
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497
|
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498 /* Remove KEY from SP. It is not an error if it did not exist. */
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499
|
|
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500 template <typename KEY_TYPE, typename VALUE_TYPE>
|
|
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501 void
|
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502 typed_splay_tree<KEY_TYPE, VALUE_TYPE>::splay_tree_remove (splay_tree_key key)
|
|
|
503 {
|
|
|
504 splay_tree_splay (key);
|
|
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505
|
|
|
506 if (root && (*comp) (root->key, key) == 0)
|
|
|
507 {
|
|
|
508 splay_tree_node left, right;
|
|
|
509
|
|
|
510 left = root->left;
|
|
|
511 right = root->right;
|
|
|
512
|
|
|
513 /* Delete the root node itself. */
|
|
|
514 VDEL (root->value);
|
|
|
515 delete root;
|
|
|
516
|
|
|
517 /* One of the children is now the root. Doesn't matter much
|
|
|
518 which, so long as we preserve the properties of the tree. */
|
|
|
519 if (left)
|
|
|
520 {
|
|
|
521 root = left;
|
|
|
522
|
|
|
523 /* If there was a right child as well, hang it off the
|
|
|
524 right-most leaf of the left child. */
|
|
|
525 if (right)
|
|
|
526 {
|
|
|
527 while (left->right)
|
|
|
528 left = left->right;
|
|
|
529 left->right = right;
|
|
|
530 }
|
|
|
531 }
|
|
|
532 else
|
|
|
533 root = right;
|
|
|
534 }
|
|
|
535 }
|
|
|
536
|
|
|
537 /* Lookup KEY in SP, returning VALUE if present, and NULL
|
|
|
538 otherwise. */
|
|
|
539
|
|
|
540 template <typename KEY_TYPE, typename VALUE_TYPE>
|
|
|
541 typename typed_splay_tree<KEY_TYPE, VALUE_TYPE>::splay_tree_node
|
|
|
542 typed_splay_tree<KEY_TYPE, VALUE_TYPE>::splay_tree_lookup (splay_tree_key key)
|
|
|
543 {
|
|
|
544 splay_tree_splay (key);
|
|
|
545
|
|
|
546 if (root && (*comp)(root->key, key) == 0)
|
|
|
547 return root;
|
|
|
548 else
|
|
|
549 return 0;
|
|
|
550 }
|
|
|
551
|
|
|
552 /* Return the node in SP with the greatest key. */
|
|
|
553
|
|
|
554 template <typename KEY_TYPE, typename VALUE_TYPE>
|
|
|
555 typename typed_splay_tree<KEY_TYPE, VALUE_TYPE>::splay_tree_node
|
|
|
556 typed_splay_tree<KEY_TYPE, VALUE_TYPE>::splay_tree_max ()
|
|
|
557 {
|
|
|
558 splay_tree_node n = root;
|
|
|
559
|
|
|
560 if (!n)
|
|
|
561 return NULL;
|
|
|
562
|
|
|
563 while (n->right)
|
|
|
564 n = n->right;
|
|
|
565
|
|
|
566 return n;
|
|
|
567 }
|
|
|
568
|
|
|
569 /* Return the node in SP with the smallest key. */
|
|
|
570
|
|
|
571 template <typename KEY_TYPE, typename VALUE_TYPE>
|
|
|
572 typename typed_splay_tree<KEY_TYPE, VALUE_TYPE>::splay_tree_node
|
|
|
573 typed_splay_tree<KEY_TYPE, VALUE_TYPE>::splay_tree_min ()
|
|
|
574 {
|
|
|
575 splay_tree_node n = root;
|
|
|
576
|
|
|
577 if (!n)
|
|
|
578 return NULL;
|
|
|
579
|
|
|
580 while (n->left)
|
|
|
581 n = n->left;
|
|
|
582
|
|
|
583 return n;
|
|
|
584 }
|
|
|
585
|
|
|
586 /* Return the immediate predecessor KEY, or NULL if there is no
|
|
|
587 predecessor. KEY need not be present in the tree. */
|
|
|
588
|
|
|
589 template <typename KEY_TYPE, typename VALUE_TYPE>
|
|
|
590 typename typed_splay_tree<KEY_TYPE, VALUE_TYPE>::splay_tree_node
|
|
|
591 typed_splay_tree<KEY_TYPE,
|
|
|
592 VALUE_TYPE>::splay_tree_predecessor (splay_tree_key key)
|
|
|
593 {
|
|
|
594 int comparison;
|
|
|
595 splay_tree_node node;
|
|
|
596
|
|
|
597 /* If the tree is empty, there is certainly no predecessor. */
|
|
|
598 if (!root)
|
|
|
599 return NULL;
|
|
|
600
|
|
|
601 /* Splay the tree around KEY. That will leave either the KEY
|
|
|
602 itself, its predecessor, or its successor at the root. */
|
|
|
603 splay_tree_splay (key);
|
|
|
604 comparison = (*comp)(root->key, key);
|
|
|
605
|
|
|
606 /* If the predecessor is at the root, just return it. */
|
|
|
607 if (comparison < 0)
|
|
|
608 return root;
|
|
|
609
|
|
|
610 /* Otherwise, find the rightmost element of the left subtree. */
|
|
|
611 node = root->left;
|
|
|
612 if (node)
|
|
|
613 while (node->right)
|
|
|
614 node = node->right;
|
|
|
615
|
|
|
616 return node;
|
|
|
617 }
|
|
|
618
|
|
|
619 /* Return the immediate successor KEY, or NULL if there is no
|
|
|
620 successor. KEY need not be present in the tree. */
|
|
|
621
|
|
|
622 template <typename KEY_TYPE, typename VALUE_TYPE>
|
|
|
623 typename typed_splay_tree<KEY_TYPE, VALUE_TYPE>::splay_tree_node
|
|
|
624 typed_splay_tree<KEY_TYPE,
|
|
|
625 VALUE_TYPE>::splay_tree_successor (splay_tree_key key)
|
|
|
626 {
|
|
|
627 int comparison;
|
|
|
628 splay_tree_node node;
|
|
|
629
|
|
|
630 /* If the tree is empty, there is certainly no successor. */
|
|
|
631 if (!root)
|
|
|
632 return NULL;
|
|
|
633
|
|
|
634 /* Splay the tree around KEY. That will leave either the KEY
|
|
|
635 itself, its predecessor, or its successor at the root. */
|
|
|
636 splay_tree_splay (key);
|
|
|
637 comparison = (*comp)(root->key, key);
|
|
|
638
|
|
|
639 /* If the successor is at the root, just return it. */
|
|
|
640 if (comparison > 0)
|
|
|
641 return root;
|
|
|
642
|
|
|
643 /* Otherwise, find the leftmost element of the right subtree. */
|
|
|
644 node = root->right;
|
|
|
645 if (node)
|
|
|
646 while (node->left)
|
|
|
647 node = node->left;
|
|
|
648
|
|
|
649 return node;
|
|
|
650 }
|
|
|
651
|
|
111
|
652 #endif /* GCC_TYPED_SPLAY_TREE_H */
|
