Steve Block | 6ded16b | 2010-05-10 14:33:55 +0100 | [diff] [blame] | 1 | // Copyright 2010 the V8 project authors. All rights reserved. |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 2 | // Use of this source code is governed by a BSD-style license that can be |
| 3 | // found in the LICENSE file. |
Steve Block | 6ded16b | 2010-05-10 14:33:55 +0100 | [diff] [blame] | 4 | |
| 5 | #ifndef V8_SPLAY_TREE_INL_H_ |
| 6 | #define V8_SPLAY_TREE_INL_H_ |
| 7 | |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 8 | #include "src/splay-tree.h" |
Steve Block | 6ded16b | 2010-05-10 14:33:55 +0100 | [diff] [blame] | 9 | |
| 10 | namespace v8 { |
| 11 | namespace internal { |
| 12 | |
| 13 | |
| 14 | template<typename Config, class Allocator> |
| 15 | SplayTree<Config, Allocator>::~SplayTree() { |
| 16 | NodeDeleter deleter; |
| 17 | ForEachNode(&deleter); |
| 18 | } |
| 19 | |
| 20 | |
| 21 | template<typename Config, class Allocator> |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 22 | bool SplayTree<Config, Allocator>::Insert(const Key& key, |
| 23 | Locator* locator) { |
Steve Block | 6ded16b | 2010-05-10 14:33:55 +0100 | [diff] [blame] | 24 | if (is_empty()) { |
| 25 | // If the tree is empty, insert the new node. |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 26 | root_ = new(allocator_) Node(key, Config::NoValue()); |
Steve Block | 6ded16b | 2010-05-10 14:33:55 +0100 | [diff] [blame] | 27 | } else { |
| 28 | // Splay on the key to move the last node on the search path |
| 29 | // for the key to the root of the tree. |
| 30 | Splay(key); |
| 31 | // Ignore repeated insertions with the same key. |
| 32 | int cmp = Config::Compare(key, root_->key_); |
| 33 | if (cmp == 0) { |
| 34 | locator->bind(root_); |
| 35 | return false; |
| 36 | } |
| 37 | // Insert the new node. |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 38 | Node* node = new(allocator_) Node(key, Config::NoValue()); |
Steve Block | 6ded16b | 2010-05-10 14:33:55 +0100 | [diff] [blame] | 39 | InsertInternal(cmp, node); |
| 40 | } |
| 41 | locator->bind(root_); |
| 42 | return true; |
| 43 | } |
| 44 | |
| 45 | |
| 46 | template<typename Config, class Allocator> |
| 47 | void SplayTree<Config, Allocator>::InsertInternal(int cmp, Node* node) { |
| 48 | if (cmp > 0) { |
| 49 | node->left_ = root_; |
| 50 | node->right_ = root_->right_; |
| 51 | root_->right_ = NULL; |
| 52 | } else { |
| 53 | node->right_ = root_; |
| 54 | node->left_ = root_->left_; |
| 55 | root_->left_ = NULL; |
| 56 | } |
| 57 | root_ = node; |
| 58 | } |
| 59 | |
| 60 | |
| 61 | template<typename Config, class Allocator> |
| 62 | bool SplayTree<Config, Allocator>::FindInternal(const Key& key) { |
| 63 | if (is_empty()) |
| 64 | return false; |
| 65 | Splay(key); |
| 66 | return Config::Compare(key, root_->key_) == 0; |
| 67 | } |
| 68 | |
| 69 | |
| 70 | template<typename Config, class Allocator> |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 71 | bool SplayTree<Config, Allocator>::Contains(const Key& key) { |
| 72 | return FindInternal(key); |
| 73 | } |
| 74 | |
| 75 | |
| 76 | template<typename Config, class Allocator> |
Steve Block | 6ded16b | 2010-05-10 14:33:55 +0100 | [diff] [blame] | 77 | bool SplayTree<Config, Allocator>::Find(const Key& key, Locator* locator) { |
| 78 | if (FindInternal(key)) { |
| 79 | locator->bind(root_); |
| 80 | return true; |
| 81 | } else { |
| 82 | return false; |
| 83 | } |
| 84 | } |
| 85 | |
| 86 | |
| 87 | template<typename Config, class Allocator> |
| 88 | bool SplayTree<Config, Allocator>::FindGreatestLessThan(const Key& key, |
| 89 | Locator* locator) { |
| 90 | if (is_empty()) |
| 91 | return false; |
| 92 | // Splay on the key to move the node with the given key or the last |
| 93 | // node on the search path to the top of the tree. |
| 94 | Splay(key); |
| 95 | // Now the result is either the root node or the greatest node in |
| 96 | // the left subtree. |
| 97 | int cmp = Config::Compare(root_->key_, key); |
| 98 | if (cmp <= 0) { |
| 99 | locator->bind(root_); |
| 100 | return true; |
| 101 | } else { |
| 102 | Node* temp = root_; |
| 103 | root_ = root_->left_; |
| 104 | bool result = FindGreatest(locator); |
| 105 | root_ = temp; |
| 106 | return result; |
| 107 | } |
| 108 | } |
| 109 | |
| 110 | |
| 111 | template<typename Config, class Allocator> |
| 112 | bool SplayTree<Config, Allocator>::FindLeastGreaterThan(const Key& key, |
| 113 | Locator* locator) { |
| 114 | if (is_empty()) |
| 115 | return false; |
| 116 | // Splay on the key to move the node with the given key or the last |
| 117 | // node on the search path to the top of the tree. |
| 118 | Splay(key); |
| 119 | // Now the result is either the root node or the least node in |
| 120 | // the right subtree. |
| 121 | int cmp = Config::Compare(root_->key_, key); |
| 122 | if (cmp >= 0) { |
| 123 | locator->bind(root_); |
| 124 | return true; |
| 125 | } else { |
| 126 | Node* temp = root_; |
| 127 | root_ = root_->right_; |
| 128 | bool result = FindLeast(locator); |
| 129 | root_ = temp; |
| 130 | return result; |
| 131 | } |
| 132 | } |
| 133 | |
| 134 | |
| 135 | template<typename Config, class Allocator> |
| 136 | bool SplayTree<Config, Allocator>::FindGreatest(Locator* locator) { |
| 137 | if (is_empty()) |
| 138 | return false; |
| 139 | Node* current = root_; |
| 140 | while (current->right_ != NULL) |
| 141 | current = current->right_; |
| 142 | locator->bind(current); |
| 143 | return true; |
| 144 | } |
| 145 | |
| 146 | |
| 147 | template<typename Config, class Allocator> |
| 148 | bool SplayTree<Config, Allocator>::FindLeast(Locator* locator) { |
| 149 | if (is_empty()) |
| 150 | return false; |
| 151 | Node* current = root_; |
| 152 | while (current->left_ != NULL) |
| 153 | current = current->left_; |
| 154 | locator->bind(current); |
| 155 | return true; |
| 156 | } |
| 157 | |
| 158 | |
| 159 | template<typename Config, class Allocator> |
| 160 | bool SplayTree<Config, Allocator>::Move(const Key& old_key, |
| 161 | const Key& new_key) { |
| 162 | if (!FindInternal(old_key)) |
| 163 | return false; |
| 164 | Node* node_to_move = root_; |
| 165 | RemoveRootNode(old_key); |
| 166 | Splay(new_key); |
| 167 | int cmp = Config::Compare(new_key, root_->key_); |
| 168 | if (cmp == 0) { |
| 169 | // A node with the target key already exists. |
| 170 | delete node_to_move; |
| 171 | return false; |
| 172 | } |
| 173 | node_to_move->key_ = new_key; |
| 174 | InsertInternal(cmp, node_to_move); |
| 175 | return true; |
| 176 | } |
| 177 | |
| 178 | |
| 179 | template<typename Config, class Allocator> |
| 180 | bool SplayTree<Config, Allocator>::Remove(const Key& key) { |
| 181 | if (!FindInternal(key)) |
| 182 | return false; |
| 183 | Node* node_to_remove = root_; |
| 184 | RemoveRootNode(key); |
| 185 | delete node_to_remove; |
| 186 | return true; |
| 187 | } |
| 188 | |
| 189 | |
| 190 | template<typename Config, class Allocator> |
| 191 | void SplayTree<Config, Allocator>::RemoveRootNode(const Key& key) { |
| 192 | if (root_->left_ == NULL) { |
| 193 | // No left child, so the new tree is just the right child. |
| 194 | root_ = root_->right_; |
| 195 | } else { |
| 196 | // Left child exists. |
| 197 | Node* right = root_->right_; |
| 198 | // Make the original left child the new root. |
| 199 | root_ = root_->left_; |
| 200 | // Splay to make sure that the new root has an empty right child. |
| 201 | Splay(key); |
| 202 | // Insert the original right child as the right child of the new |
| 203 | // root. |
| 204 | root_->right_ = right; |
| 205 | } |
| 206 | } |
| 207 | |
| 208 | |
| 209 | template<typename Config, class Allocator> |
| 210 | void SplayTree<Config, Allocator>::Splay(const Key& key) { |
| 211 | if (is_empty()) |
| 212 | return; |
Ben Murdoch | 3ef787d | 2012-04-12 10:51:47 +0100 | [diff] [blame] | 213 | Node dummy_node(Config::kNoKey, Config::NoValue()); |
Steve Block | 6ded16b | 2010-05-10 14:33:55 +0100 | [diff] [blame] | 214 | // Create a dummy node. The use of the dummy node is a bit |
| 215 | // counter-intuitive: The right child of the dummy node will hold |
| 216 | // the L tree of the algorithm. The left child of the dummy node |
| 217 | // will hold the R tree of the algorithm. Using a dummy node, left |
| 218 | // and right will always be nodes and we avoid special cases. |
| 219 | Node* dummy = &dummy_node; |
| 220 | Node* left = dummy; |
| 221 | Node* right = dummy; |
| 222 | Node* current = root_; |
| 223 | while (true) { |
| 224 | int cmp = Config::Compare(key, current->key_); |
| 225 | if (cmp < 0) { |
| 226 | if (current->left_ == NULL) |
| 227 | break; |
| 228 | if (Config::Compare(key, current->left_->key_) < 0) { |
| 229 | // Rotate right. |
| 230 | Node* temp = current->left_; |
| 231 | current->left_ = temp->right_; |
| 232 | temp->right_ = current; |
| 233 | current = temp; |
| 234 | if (current->left_ == NULL) |
| 235 | break; |
| 236 | } |
| 237 | // Link right. |
| 238 | right->left_ = current; |
| 239 | right = current; |
| 240 | current = current->left_; |
| 241 | } else if (cmp > 0) { |
| 242 | if (current->right_ == NULL) |
| 243 | break; |
| 244 | if (Config::Compare(key, current->right_->key_) > 0) { |
| 245 | // Rotate left. |
| 246 | Node* temp = current->right_; |
| 247 | current->right_ = temp->left_; |
| 248 | temp->left_ = current; |
| 249 | current = temp; |
| 250 | if (current->right_ == NULL) |
| 251 | break; |
| 252 | } |
| 253 | // Link left. |
| 254 | left->right_ = current; |
| 255 | left = current; |
| 256 | current = current->right_; |
| 257 | } else { |
| 258 | break; |
| 259 | } |
| 260 | } |
| 261 | // Assemble. |
| 262 | left->right_ = current->left_; |
| 263 | right->left_ = current->right_; |
| 264 | current->left_ = dummy->right_; |
| 265 | current->right_ = dummy->left_; |
| 266 | root_ = current; |
| 267 | } |
| 268 | |
| 269 | |
| 270 | template <typename Config, class Allocator> template <class Callback> |
| 271 | void SplayTree<Config, Allocator>::ForEach(Callback* callback) { |
| 272 | NodeToPairAdaptor<Callback> callback_adaptor(callback); |
| 273 | ForEachNode(&callback_adaptor); |
| 274 | } |
| 275 | |
| 276 | |
| 277 | template <typename Config, class Allocator> template <class Callback> |
| 278 | void SplayTree<Config, Allocator>::ForEachNode(Callback* callback) { |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 279 | if (root_ == NULL) return; |
Steve Block | 6ded16b | 2010-05-10 14:33:55 +0100 | [diff] [blame] | 280 | // Pre-allocate some space for tiny trees. |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 281 | List<Node*, Allocator> nodes_to_visit(10, allocator_); |
| 282 | nodes_to_visit.Add(root_, allocator_); |
Steve Block | 6ded16b | 2010-05-10 14:33:55 +0100 | [diff] [blame] | 283 | int pos = 0; |
| 284 | while (pos < nodes_to_visit.length()) { |
| 285 | Node* node = nodes_to_visit[pos++]; |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 286 | if (node->left() != NULL) nodes_to_visit.Add(node->left(), allocator_); |
| 287 | if (node->right() != NULL) nodes_to_visit.Add(node->right(), allocator_); |
Steve Block | 6ded16b | 2010-05-10 14:33:55 +0100 | [diff] [blame] | 288 | callback->Call(node); |
| 289 | } |
| 290 | } |
| 291 | |
| 292 | |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 293 | } // namespace internal |
| 294 | } // namespace v8 |
Steve Block | 6ded16b | 2010-05-10 14:33:55 +0100 | [diff] [blame] | 295 | |
| 296 | #endif // V8_SPLAY_TREE_INL_H_ |