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| 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_H_ |
| 29 #define V8_SPLAY_TREE_H_ |
| 30 |
| 31 namespace v8 { |
| 32 namespace internal { |
| 33 |
| 34 |
| 35 // A splay tree. The config type parameter encapsulates the different |
| 36 // configurations of a concrete splay tree: |
| 37 // |
| 38 // typedef Key: the key type |
| 39 // typedef Value: the value type |
| 40 // static const kNoKey: the dummy key used when no key is set |
| 41 // static const kNoValue: the dummy value used to initialize nodes |
| 42 // int (Compare)(Key& a, Key& b) -> {-1, 0, 1}: comparison function |
| 43 // |
| 44 // The tree is also parameterized by an allocation policy |
| 45 // (Allocator). The policy is used for allocating lists in the C free |
| 46 // store or the zone; see zone.h. |
| 47 |
| 48 // Forward defined as |
| 49 // template <typename Config, class Allocator = FreeStoreAllocationPolicy> |
| 50 // class SplayTree; |
| 51 template <typename Config, class Allocator> |
| 52 class SplayTree { |
| 53 public: |
| 54 typedef typename Config::Key Key; |
| 55 typedef typename Config::Value Value; |
| 56 |
| 57 class Locator; |
| 58 |
| 59 SplayTree() : root_(NULL) { } |
| 60 ~SplayTree(); |
| 61 |
| 62 INLINE(void* operator new(size_t size)) { |
| 63 return Allocator::New(static_cast<int>(size)); |
| 64 } |
| 65 INLINE(void operator delete(void* p, size_t)) { return Allocator::Delete(p); } |
| 66 |
| 67 // Inserts the given key in this tree with the given value. Returns |
| 68 // true if a node was inserted, otherwise false. If found the locator |
| 69 // is enabled and provides access to the mapping for the key. |
| 70 bool Insert(const Key& key, Locator* locator); |
| 71 |
| 72 // Looks up the key in this tree and returns true if it was found, |
| 73 // otherwise false. If the node is found the locator is enabled and |
| 74 // provides access to the mapping for the key. |
| 75 bool Find(const Key& key, Locator* locator); |
| 76 |
| 77 // Finds the mapping with the greatest key less than or equal to the |
| 78 // given key. |
| 79 bool FindGreatestLessThan(const Key& key, Locator* locator); |
| 80 |
| 81 // Find the mapping with the greatest key in this tree. |
| 82 bool FindGreatest(Locator* locator); |
| 83 |
| 84 // Finds the mapping with the least key greater than or equal to the |
| 85 // given key. |
| 86 bool FindLeastGreaterThan(const Key& key, Locator* locator); |
| 87 |
| 88 // Find the mapping with the least key in this tree. |
| 89 bool FindLeast(Locator* locator); |
| 90 |
| 91 // Remove the node with the given key from the tree. |
| 92 bool Remove(const Key& key); |
| 93 |
| 94 bool is_empty() { return root_ == NULL; } |
| 95 |
| 96 // Perform the splay operation for the given key. Moves the node with |
| 97 // the given key to the top of the tree. If no node has the given |
| 98 // key, the last node on the search path is moved to the top of the |
| 99 // tree. |
| 100 void Splay(const Key& key); |
| 101 |
| 102 class Node { |
| 103 public: |
| 104 Node(const Key& key, const Value& value) |
| 105 : key_(key), |
| 106 value_(value), |
| 107 left_(NULL), |
| 108 right_(NULL) { } |
| 109 |
| 110 INLINE(void* operator new(size_t size)) { |
| 111 return Allocator::New(static_cast<int>(size)); |
| 112 } |
| 113 INLINE(void operator delete(void* p, size_t)) { |
| 114 return Allocator::Delete(p); |
| 115 } |
| 116 |
| 117 Key key() { return key_; } |
| 118 Value value() { return value_; } |
| 119 Node* left() { return left_; } |
| 120 Node* right() { return right_; } |
| 121 private: |
| 122 |
| 123 friend class SplayTree; |
| 124 friend class Locator; |
| 125 Key key_; |
| 126 Value value_; |
| 127 Node* left_; |
| 128 Node* right_; |
| 129 }; |
| 130 |
| 131 // A locator provides access to a node in the tree without actually |
| 132 // exposing the node. |
| 133 class Locator BASE_EMBEDDED { |
| 134 public: |
| 135 explicit Locator(Node* node) : node_(node) { } |
| 136 Locator() : node_(NULL) { } |
| 137 const Key& key() { return node_->key_; } |
| 138 Value& value() { return node_->value_; } |
| 139 void set_value(const Value& value) { node_->value_ = value; } |
| 140 inline void bind(Node* node) { node_ = node; } |
| 141 private: |
| 142 Node* node_; |
| 143 }; |
| 144 |
| 145 template <class Callback> |
| 146 void ForEach(Callback* callback); |
| 147 |
| 148 protected: |
| 149 |
| 150 // Resets tree root. Existing nodes become unreachable. |
| 151 void ResetRoot() { root_ = NULL; } |
| 152 |
| 153 private: |
| 154 |
| 155 template<class Callback> |
| 156 class NodeToPairAdaptor BASE_EMBEDDED { |
| 157 public: |
| 158 explicit NodeToPairAdaptor(Callback* callback) |
| 159 : callback_(callback) { } |
| 160 void Call(Node* node) { |
| 161 callback_->Call(node->key(), node->value()); |
| 162 } |
| 163 |
| 164 private: |
| 165 Callback* callback_; |
| 166 |
| 167 DISALLOW_COPY_AND_ASSIGN(NodeToPairAdaptor); |
| 168 }; |
| 169 |
| 170 class NodeDeleter BASE_EMBEDDED { |
| 171 public: |
| 172 NodeDeleter() { } |
| 173 void Call(Node* node) { delete node; } |
| 174 |
| 175 private: |
| 176 |
| 177 DISALLOW_COPY_AND_ASSIGN(NodeDeleter); |
| 178 }; |
| 179 |
| 180 template <class Callback> |
| 181 void ForEachNode(Callback* callback); |
| 182 |
| 183 Node* root_; |
| 184 |
| 185 DISALLOW_COPY_AND_ASSIGN(SplayTree); |
| 186 }; |
| 187 |
| 188 |
| 189 } } // namespace v8::internal |
| 190 |
| 191 #endif // V8_SPLAY_TREE_H_ |
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