| // Copyright 2010 the V8 project authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #ifndef V8_SPLAY_TREE_H_ |
| #define V8_SPLAY_TREE_H_ |
| |
| #include "src/allocation.h" |
| |
| namespace v8 { |
| namespace internal { |
| |
| |
| // A splay tree. The config type parameter encapsulates the different |
| // configurations of a concrete splay tree: |
| // |
| // typedef Key: the key type |
| // typedef Value: the value type |
| // static const Key kNoKey: the dummy key used when no key is set |
| // static Value kNoValue(): the dummy value used to initialize nodes |
| // static int (Compare)(Key& a, Key& b) -> {-1, 0, 1}: comparison function |
| // |
| // The tree is also parameterized by an allocation policy |
| // (Allocator). The policy is used for allocating lists in the C free |
| // store or the zone; see zone.h. |
| |
| // Forward defined as |
| // template <typename Config, class Allocator = FreeStoreAllocationPolicy> |
| // class SplayTree; |
| template <typename Config, class AllocationPolicy> |
| class SplayTree { |
| public: |
| typedef typename Config::Key Key; |
| typedef typename Config::Value Value; |
| |
| class Locator; |
| |
| explicit SplayTree(AllocationPolicy allocator = AllocationPolicy()) |
| : root_(nullptr), allocator_(allocator) {} |
| ~SplayTree(); |
| |
| INLINE(void* operator new(size_t size, |
| AllocationPolicy allocator = AllocationPolicy())) { |
| return allocator.New(static_cast<int>(size)); |
| } |
| INLINE(void operator delete(void* p)) { |
| AllocationPolicy::Delete(p); |
| } |
| // Please the MSVC compiler. We should never have to execute this. |
| INLINE(void operator delete(void* p, AllocationPolicy policy)) { |
| UNREACHABLE(); |
| } |
| |
| AllocationPolicy allocator() { return allocator_; } |
| |
| // Checks if there is a mapping for the key. |
| bool Contains(const Key& key); |
| |
| // Inserts the given key in this tree with the given value. Returns |
| // true if a node was inserted, otherwise false. If found the locator |
| // is enabled and provides access to the mapping for the key. |
| bool Insert(const Key& key, Locator* locator); |
| |
| // Looks up the key in this tree and returns true if it was found, |
| // otherwise false. If the node is found the locator is enabled and |
| // provides access to the mapping for the key. |
| bool Find(const Key& key, Locator* locator); |
| |
| // Finds the mapping with the greatest key less than or equal to the |
| // given key. |
| bool FindGreatestLessThan(const Key& key, Locator* locator); |
| |
| // Find the mapping with the greatest key in this tree. |
| bool FindGreatest(Locator* locator); |
| |
| // Finds the mapping with the least key greater than or equal to the |
| // given key. |
| bool FindLeastGreaterThan(const Key& key, Locator* locator); |
| |
| // Find the mapping with the least key in this tree. |
| bool FindLeast(Locator* locator); |
| |
| // Move the node from one key to another. |
| bool Move(const Key& old_key, const Key& new_key); |
| |
| // Remove the node with the given key from the tree. |
| bool Remove(const Key& key); |
| |
| // Remove all keys from the tree. |
| void Clear() { ResetRoot(); } |
| |
| bool is_empty() { return root_ == nullptr; } |
| |
| // Perform the splay operation for the given key. Moves the node with |
| // the given key to the top of the tree. If no node has the given |
| // key, the last node on the search path is moved to the top of the |
| // tree. |
| void Splay(const Key& key); |
| |
| class Node { |
| public: |
| Node(const Key& key, const Value& value) |
| : key_(key), value_(value), left_(nullptr), right_(nullptr) {} |
| |
| INLINE(void* operator new(size_t size, AllocationPolicy allocator)) { |
| return allocator.New(static_cast<int>(size)); |
| } |
| INLINE(void operator delete(void* p)) { |
| return AllocationPolicy::Delete(p); |
| } |
| // Please the MSVC compiler. We should never have to execute |
| // this. |
| INLINE(void operator delete(void* p, AllocationPolicy allocator)) { |
| UNREACHABLE(); |
| } |
| |
| Key key() { return key_; } |
| Value value() { return value_; } |
| Node* left() { return left_; } |
| Node* right() { return right_; } |
| |
| private: |
| friend class SplayTree; |
| friend class Locator; |
| Key key_; |
| Value value_; |
| Node* left_; |
| Node* right_; |
| }; |
| |
| // A locator provides access to a node in the tree without actually |
| // exposing the node. |
| class Locator BASE_EMBEDDED { |
| public: |
| explicit Locator(Node* node) : node_(node) { } |
| Locator() : node_(nullptr) {} |
| const Key& key() { return node_->key_; } |
| Value& value() { return node_->value_; } |
| void set_value(const Value& value) { node_->value_ = value; } |
| inline void bind(Node* node) { node_ = node; } |
| |
| private: |
| Node* node_; |
| }; |
| |
| template <class Callback> |
| void ForEach(Callback* callback); |
| |
| protected: |
| // Resets tree root. Existing nodes become unreachable. |
| void ResetRoot() { root_ = nullptr; } |
| |
| private: |
| // Search for a node with a given key. If found, root_ points |
| // to the node. |
| bool FindInternal(const Key& key); |
| |
| // Inserts a node assuming that root_ is already set up. |
| void InsertInternal(int cmp, Node* node); |
| |
| // Removes root_ node. |
| void RemoveRootNode(const Key& key); |
| |
| template<class Callback> |
| class NodeToPairAdaptor BASE_EMBEDDED { |
| public: |
| explicit NodeToPairAdaptor(Callback* callback) |
| : callback_(callback) { } |
| void Call(Node* node) { |
| callback_->Call(node->key(), node->value()); |
| } |
| |
| private: |
| Callback* callback_; |
| |
| DISALLOW_COPY_AND_ASSIGN(NodeToPairAdaptor); |
| }; |
| |
| class NodeDeleter BASE_EMBEDDED { |
| public: |
| NodeDeleter() { } |
| void Call(Node* node) { AllocationPolicy::Delete(node); } |
| |
| private: |
| DISALLOW_COPY_AND_ASSIGN(NodeDeleter); |
| }; |
| |
| template <class Callback> |
| void ForEachNode(Callback* callback); |
| |
| Node* root_; |
| AllocationPolicy allocator_; |
| |
| DISALLOW_COPY_AND_ASSIGN(SplayTree); |
| }; |
| |
| |
| } // namespace internal |
| } // namespace v8 |
| |
| #endif // V8_SPLAY_TREE_H_ |