Steve Block | 6ded16b | 2010-05-10 14:33:55 +0100 | [diff] [blame] | 1 | // Copyright 2010 the V8 project authors. All rights reserved. |
| 2 | // Redistribution and use in source and binary forms, with or without |
| 3 | // modification, are permitted provided that the following conditions are |
| 4 | // met: |
| 5 | // |
| 6 | // * Redistributions of source code must retain the above copyright |
| 7 | // notice, this list of conditions and the following disclaimer. |
| 8 | // * Redistributions in binary form must reproduce the above |
| 9 | // copyright notice, this list of conditions and the following |
| 10 | // disclaimer in the documentation and/or other materials provided |
| 11 | // with the distribution. |
| 12 | // * Neither the name of Google Inc. nor the names of its |
| 13 | // contributors may be used to endorse or promote products derived |
| 14 | // from this software without specific prior written permission. |
| 15 | // |
| 16 | // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| 17 | // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| 18 | // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| 19 | // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| 20 | // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| 21 | // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| 22 | // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| 23 | // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| 24 | // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| 25 | // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| 26 | // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| 27 | |
| 28 | #ifndef V8_SPLAY_TREE_INL_H_ |
| 29 | #define V8_SPLAY_TREE_INL_H_ |
| 30 | |
| 31 | #include "splay-tree.h" |
| 32 | |
| 33 | namespace v8 { |
| 34 | namespace internal { |
| 35 | |
| 36 | |
| 37 | template<typename Config, class Allocator> |
| 38 | SplayTree<Config, Allocator>::~SplayTree() { |
| 39 | NodeDeleter deleter; |
| 40 | ForEachNode(&deleter); |
| 41 | } |
| 42 | |
| 43 | |
| 44 | template<typename Config, class Allocator> |
| 45 | bool SplayTree<Config, Allocator>::Insert(const Key& key, Locator* locator) { |
| 46 | if (is_empty()) { |
| 47 | // If the tree is empty, insert the new node. |
Ben Murdoch | 85b7179 | 2012-04-11 18:30:58 +0100 | [diff] [blame^] | 48 | root_ = new Node(key, Config::kNoValue); |
Steve Block | 6ded16b | 2010-05-10 14:33:55 +0100 | [diff] [blame] | 49 | } else { |
| 50 | // Splay on the key to move the last node on the search path |
| 51 | // for the key to the root of the tree. |
| 52 | Splay(key); |
| 53 | // Ignore repeated insertions with the same key. |
| 54 | int cmp = Config::Compare(key, root_->key_); |
| 55 | if (cmp == 0) { |
| 56 | locator->bind(root_); |
| 57 | return false; |
| 58 | } |
| 59 | // Insert the new node. |
Ben Murdoch | 85b7179 | 2012-04-11 18:30:58 +0100 | [diff] [blame^] | 60 | Node* node = new Node(key, Config::kNoValue); |
Steve Block | 6ded16b | 2010-05-10 14:33:55 +0100 | [diff] [blame] | 61 | InsertInternal(cmp, node); |
| 62 | } |
| 63 | locator->bind(root_); |
| 64 | return true; |
| 65 | } |
| 66 | |
| 67 | |
| 68 | template<typename Config, class Allocator> |
| 69 | void SplayTree<Config, Allocator>::InsertInternal(int cmp, Node* node) { |
| 70 | if (cmp > 0) { |
| 71 | node->left_ = root_; |
| 72 | node->right_ = root_->right_; |
| 73 | root_->right_ = NULL; |
| 74 | } else { |
| 75 | node->right_ = root_; |
| 76 | node->left_ = root_->left_; |
| 77 | root_->left_ = NULL; |
| 78 | } |
| 79 | root_ = node; |
| 80 | } |
| 81 | |
| 82 | |
| 83 | template<typename Config, class Allocator> |
| 84 | bool SplayTree<Config, Allocator>::FindInternal(const Key& key) { |
| 85 | if (is_empty()) |
| 86 | return false; |
| 87 | Splay(key); |
| 88 | return Config::Compare(key, root_->key_) == 0; |
| 89 | } |
| 90 | |
| 91 | |
| 92 | template<typename Config, class Allocator> |
| 93 | bool SplayTree<Config, Allocator>::Find(const Key& key, Locator* locator) { |
| 94 | if (FindInternal(key)) { |
| 95 | locator->bind(root_); |
| 96 | return true; |
| 97 | } else { |
| 98 | return false; |
| 99 | } |
| 100 | } |
| 101 | |
| 102 | |
| 103 | template<typename Config, class Allocator> |
| 104 | bool SplayTree<Config, Allocator>::FindGreatestLessThan(const Key& key, |
| 105 | Locator* locator) { |
| 106 | if (is_empty()) |
| 107 | return false; |
| 108 | // Splay on the key to move the node with the given key or the last |
| 109 | // node on the search path to the top of the tree. |
| 110 | Splay(key); |
| 111 | // Now the result is either the root node or the greatest node in |
| 112 | // the left subtree. |
| 113 | int cmp = Config::Compare(root_->key_, key); |
| 114 | if (cmp <= 0) { |
| 115 | locator->bind(root_); |
| 116 | return true; |
| 117 | } else { |
| 118 | Node* temp = root_; |
| 119 | root_ = root_->left_; |
| 120 | bool result = FindGreatest(locator); |
| 121 | root_ = temp; |
| 122 | return result; |
| 123 | } |
| 124 | } |
| 125 | |
| 126 | |
| 127 | template<typename Config, class Allocator> |
| 128 | bool SplayTree<Config, Allocator>::FindLeastGreaterThan(const Key& key, |
| 129 | Locator* locator) { |
| 130 | if (is_empty()) |
| 131 | return false; |
| 132 | // Splay on the key to move the node with the given key or the last |
| 133 | // node on the search path to the top of the tree. |
| 134 | Splay(key); |
| 135 | // Now the result is either the root node or the least node in |
| 136 | // the right subtree. |
| 137 | int cmp = Config::Compare(root_->key_, key); |
| 138 | if (cmp >= 0) { |
| 139 | locator->bind(root_); |
| 140 | return true; |
| 141 | } else { |
| 142 | Node* temp = root_; |
| 143 | root_ = root_->right_; |
| 144 | bool result = FindLeast(locator); |
| 145 | root_ = temp; |
| 146 | return result; |
| 147 | } |
| 148 | } |
| 149 | |
| 150 | |
| 151 | template<typename Config, class Allocator> |
| 152 | bool SplayTree<Config, Allocator>::FindGreatest(Locator* locator) { |
| 153 | if (is_empty()) |
| 154 | return false; |
| 155 | Node* current = root_; |
| 156 | while (current->right_ != NULL) |
| 157 | current = current->right_; |
| 158 | locator->bind(current); |
| 159 | return true; |
| 160 | } |
| 161 | |
| 162 | |
| 163 | template<typename Config, class Allocator> |
| 164 | bool SplayTree<Config, Allocator>::FindLeast(Locator* locator) { |
| 165 | if (is_empty()) |
| 166 | return false; |
| 167 | Node* current = root_; |
| 168 | while (current->left_ != NULL) |
| 169 | current = current->left_; |
| 170 | locator->bind(current); |
| 171 | return true; |
| 172 | } |
| 173 | |
| 174 | |
| 175 | template<typename Config, class Allocator> |
| 176 | bool SplayTree<Config, Allocator>::Move(const Key& old_key, |
| 177 | const Key& new_key) { |
| 178 | if (!FindInternal(old_key)) |
| 179 | return false; |
| 180 | Node* node_to_move = root_; |
| 181 | RemoveRootNode(old_key); |
| 182 | Splay(new_key); |
| 183 | int cmp = Config::Compare(new_key, root_->key_); |
| 184 | if (cmp == 0) { |
| 185 | // A node with the target key already exists. |
| 186 | delete node_to_move; |
| 187 | return false; |
| 188 | } |
| 189 | node_to_move->key_ = new_key; |
| 190 | InsertInternal(cmp, node_to_move); |
| 191 | return true; |
| 192 | } |
| 193 | |
| 194 | |
| 195 | template<typename Config, class Allocator> |
| 196 | bool SplayTree<Config, Allocator>::Remove(const Key& key) { |
| 197 | if (!FindInternal(key)) |
| 198 | return false; |
| 199 | Node* node_to_remove = root_; |
| 200 | RemoveRootNode(key); |
| 201 | delete node_to_remove; |
| 202 | return true; |
| 203 | } |
| 204 | |
| 205 | |
| 206 | template<typename Config, class Allocator> |
| 207 | void SplayTree<Config, Allocator>::RemoveRootNode(const Key& key) { |
| 208 | if (root_->left_ == NULL) { |
| 209 | // No left child, so the new tree is just the right child. |
| 210 | root_ = root_->right_; |
| 211 | } else { |
| 212 | // Left child exists. |
| 213 | Node* right = root_->right_; |
| 214 | // Make the original left child the new root. |
| 215 | root_ = root_->left_; |
| 216 | // Splay to make sure that the new root has an empty right child. |
| 217 | Splay(key); |
| 218 | // Insert the original right child as the right child of the new |
| 219 | // root. |
| 220 | root_->right_ = right; |
| 221 | } |
| 222 | } |
| 223 | |
| 224 | |
| 225 | template<typename Config, class Allocator> |
| 226 | void SplayTree<Config, Allocator>::Splay(const Key& key) { |
| 227 | if (is_empty()) |
| 228 | return; |
Ben Murdoch | 85b7179 | 2012-04-11 18:30:58 +0100 | [diff] [blame^] | 229 | Node dummy_node(Config::kNoKey, Config::kNoValue); |
Steve Block | 6ded16b | 2010-05-10 14:33:55 +0100 | [diff] [blame] | 230 | // Create a dummy node. The use of the dummy node is a bit |
| 231 | // counter-intuitive: The right child of the dummy node will hold |
| 232 | // the L tree of the algorithm. The left child of the dummy node |
| 233 | // will hold the R tree of the algorithm. Using a dummy node, left |
| 234 | // and right will always be nodes and we avoid special cases. |
| 235 | Node* dummy = &dummy_node; |
| 236 | Node* left = dummy; |
| 237 | Node* right = dummy; |
| 238 | Node* current = root_; |
| 239 | while (true) { |
| 240 | int cmp = Config::Compare(key, current->key_); |
| 241 | if (cmp < 0) { |
| 242 | if (current->left_ == NULL) |
| 243 | break; |
| 244 | if (Config::Compare(key, current->left_->key_) < 0) { |
| 245 | // Rotate right. |
| 246 | Node* temp = current->left_; |
| 247 | current->left_ = temp->right_; |
| 248 | temp->right_ = current; |
| 249 | current = temp; |
| 250 | if (current->left_ == NULL) |
| 251 | break; |
| 252 | } |
| 253 | // Link right. |
| 254 | right->left_ = current; |
| 255 | right = current; |
| 256 | current = current->left_; |
| 257 | } else if (cmp > 0) { |
| 258 | if (current->right_ == NULL) |
| 259 | break; |
| 260 | if (Config::Compare(key, current->right_->key_) > 0) { |
| 261 | // Rotate left. |
| 262 | Node* temp = current->right_; |
| 263 | current->right_ = temp->left_; |
| 264 | temp->left_ = current; |
| 265 | current = temp; |
| 266 | if (current->right_ == NULL) |
| 267 | break; |
| 268 | } |
| 269 | // Link left. |
| 270 | left->right_ = current; |
| 271 | left = current; |
| 272 | current = current->right_; |
| 273 | } else { |
| 274 | break; |
| 275 | } |
| 276 | } |
| 277 | // Assemble. |
| 278 | left->right_ = current->left_; |
| 279 | right->left_ = current->right_; |
| 280 | current->left_ = dummy->right_; |
| 281 | current->right_ = dummy->left_; |
| 282 | root_ = current; |
| 283 | } |
| 284 | |
| 285 | |
| 286 | template <typename Config, class Allocator> template <class Callback> |
| 287 | void SplayTree<Config, Allocator>::ForEach(Callback* callback) { |
| 288 | NodeToPairAdaptor<Callback> callback_adaptor(callback); |
| 289 | ForEachNode(&callback_adaptor); |
| 290 | } |
| 291 | |
| 292 | |
| 293 | template <typename Config, class Allocator> template <class Callback> |
| 294 | void SplayTree<Config, Allocator>::ForEachNode(Callback* callback) { |
| 295 | // Pre-allocate some space for tiny trees. |
| 296 | List<Node*, Allocator> nodes_to_visit(10); |
| 297 | if (root_ != NULL) nodes_to_visit.Add(root_); |
| 298 | int pos = 0; |
| 299 | while (pos < nodes_to_visit.length()) { |
| 300 | Node* node = nodes_to_visit[pos++]; |
| 301 | if (node->left() != NULL) nodes_to_visit.Add(node->left()); |
| 302 | if (node->right() != NULL) nodes_to_visit.Add(node->right()); |
| 303 | callback->Call(node); |
| 304 | } |
| 305 | } |
| 306 | |
| 307 | |
| 308 | } } // namespace v8::internal |
| 309 | |
| 310 | #endif // V8_SPLAY_TREE_INL_H_ |