Split an allocation policy into an allocator and a deallocator.

src/splay-tree-inl.h

 // Copyright 2010 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 16 matching lines @@
 
 #ifndef V8_SPLAY_TREE_INL_H_
 #define V8_SPLAY_TREE_INL_H_
 
 #include "splay-tree.h"
 
 namespace v8 {
 namespace internal {
 
 
-template<typename Config, class Allocator>
-SplayTree<Config, Allocator>::~SplayTree() {
-  NodeDeleter deleter;
+template<typename Config, class AllocationPolicy>
+SplayTree<Config, AllocationPolicy>::~SplayTree() {
+  NodeDeleter deleter(deallocator_);
   ForEachNode(&deleter);
 }
 
 
-template<typename Config, class Allocator>
-bool SplayTree<Config, Allocator>::Insert(const Key& key, Locator* locator) {
+template<typename Config, class AllocationPolicy>
+bool SplayTree<Config, AllocationPolicy>::Insert(const Key& key,
+                                                 Locator* locator,
+                                                 Allocator allocator) {
   if (is_empty()) {
     // If the tree is empty, insert the new node.
-    root_ = new Node(key, Config::NoValue());
+    root_ = new(allocator) Node(key, Config::NoValue());
   } else {
     // Splay on the key to move the last node on the search path
     // for the key to the root of the tree.
     Splay(key);
     // Ignore repeated insertions with the same key.
     int cmp = Config::Compare(key, root_->key_);
     if (cmp == 0) {
       locator->bind(root_);
       return false;
     }
     // Insert the new node.
-    Node* node = new Node(key, Config::NoValue());
+    Node* node = new(allocator) Node(key, Config::NoValue());
     InsertInternal(cmp, node);
   }
   locator->bind(root_);
   return true;
 }
 
 
-template<typename Config, class Allocator>
-void SplayTree<Config, Allocator>::InsertInternal(int cmp, Node* node) {
+template<typename Config, class AllocationPolicy>
+void SplayTree<Config, AllocationPolicy>::InsertInternal(int cmp, Node* node) {
   if (cmp > 0) {
     node->left_ = root_;
     node->right_ = root_->right_;
     root_->right_ = NULL;
   } else {
     node->right_ = root_;
     node->left_ = root_->left_;
     root_->left_ = NULL;
   }
   root_ = node;
 }
 
 
-template<typename Config, class Allocator>
-bool SplayTree<Config, Allocator>::FindInternal(const Key& key) {
+template<typename Config, class AllocationPolicy>
+bool SplayTree<Config, AllocationPolicy>::FindInternal(const Key& key) {
   if (is_empty())
     return false;
   Splay(key);
   return Config::Compare(key, root_->key_) == 0;
 }
 
 
-template<typename Config, class Allocator>
-bool SplayTree<Config, Allocator>::Find(const Key& key, Locator* locator) {
+template<typename Config, class AllocationPolicy>
+bool SplayTree<Config, AllocationPolicy>::Find(const Key& key,
+                                               Locator* locator) {
   if (FindInternal(key)) {
     locator->bind(root_);
     return true;
   } else {
     return false;
   }
 }
 
 
-template<typename Config, class Allocator>
-bool SplayTree<Config, Allocator>::FindGreatestLessThan(const Key& key,
-                                                        Locator* locator) {
+template<typename Config, class AllocationPolicy>
+bool SplayTree<Config, AllocationPolicy>::FindGreatestLessThan(
+    const Key& key, Locator* locator) {
   if (is_empty())
     return false;
   // Splay on the key to move the node with the given key or the last
   // node on the search path to the top of the tree.
   Splay(key);
   // Now the result is either the root node or the greatest node in
   // the left subtree.
   int cmp = Config::Compare(root_->key_, key);
   if (cmp <= 0) {
     locator->bind(root_);
     return true;
   } else {
     Node* temp = root_;
     root_ = root_->left_;
     bool result = FindGreatest(locator);
     root_ = temp;
     return result;
   }
 }
 
 
-template<typename Config, class Allocator>
-bool SplayTree<Config, Allocator>::FindLeastGreaterThan(const Key& key,
-                                                        Locator* locator) {
+template<typename Config, class AllocationPolicy>
+bool SplayTree<Config, AllocationPolicy>::FindLeastGreaterThan(
+    const Key& key, Locator* locator) {
   if (is_empty())
     return false;
   // Splay on the key to move the node with the given key or the last
   // node on the search path to the top of the tree.
   Splay(key);
   // Now the result is either the root node or the least node in
   // the right subtree.
   int cmp = Config::Compare(root_->key_, key);
   if (cmp >= 0) {
     locator->bind(root_);
     return true;
   } else {
     Node* temp = root_;
     root_ = root_->right_;
     bool result = FindLeast(locator);
     root_ = temp;
     return result;
   }
 }
 
 
-template<typename Config, class Allocator>
-bool SplayTree<Config, Allocator>::FindGreatest(Locator* locator) {
+template<typename Config, class AllocationPolicy>
+bool SplayTree<Config, AllocationPolicy>::FindGreatest(Locator* locator) {
   if (is_empty())
     return false;
   Node* current = root_;
   while (current->right_ != NULL)
     current = current->right_;
   locator->bind(current);
   return true;
 }
 
 
-template<typename Config, class Allocator>
-bool SplayTree<Config, Allocator>::FindLeast(Locator* locator) {
+template<typename Config, class AllocationPolicy>
+bool SplayTree<Config, AllocationPolicy>::FindLeast(Locator* locator) {
   if (is_empty())
     return false;
   Node* current = root_;
   while (current->left_ != NULL)
     current = current->left_;
   locator->bind(current);
   return true;
 }
 
 
-template<typename Config, class Allocator>
-bool SplayTree<Config, Allocator>::Move(const Key& old_key,
-                                        const Key& new_key) {
+template<typename Config, class AllocationPolicy>
+bool SplayTree<Config, AllocationPolicy>::Move(const Key& old_key,
+                                               const Key& new_key) {
   if (!FindInternal(old_key))
     return false;
   Node* node_to_move = root_;
   RemoveRootNode(old_key);
   Splay(new_key);
   int cmp = Config::Compare(new_key, root_->key_);
   if (cmp == 0) {
     // A node with the target key already exists.
-    delete node_to_move;
+    deallocator_.Delete(node_to_move);

[danno, 2012/05/31 11:03:36]

Yikes! You never call the node's destructor this way. I think you need to have
the node contain the deallocator, too, for symmetry.

     return false;
   }
   node_to_move->key_ = new_key;
   InsertInternal(cmp, node_to_move);
   return true;
 }
 
 
-template<typename Config, class Allocator>
-bool SplayTree<Config, Allocator>::Remove(const Key& key) {
+template<typename Config, class AllocationPolicy>
+bool SplayTree<Config, AllocationPolicy>::Remove(const Key& key) {
   if (!FindInternal(key))
     return false;
   Node* node_to_remove = root_;
   RemoveRootNode(key);
   delete node_to_remove;
   return true;
 }
 
 
-template<typename Config, class Allocator>
-void SplayTree<Config, Allocator>::RemoveRootNode(const Key& key) {
+template<typename Config, class AllocationPolicy>
+void SplayTree<Config, AllocationPolicy>::RemoveRootNode(const Key& key) {
   if (root_->left_ == NULL) {
     // No left child, so the new tree is just the right child.
     root_ = root_->right_;
   } else {
     // Left child exists.
     Node* right = root_->right_;
     // Make the original left child the new root.
     root_ = root_->left_;
     // Splay to make sure that the new root has an empty right child.
     Splay(key);
     // Insert the original right child as the right child of the new
     // root.
     root_->right_ = right;
   }
 }
 
 
-template<typename Config, class Allocator>
-void SplayTree<Config, Allocator>::Splay(const Key& key) {
+template<typename Config, class AllocationPolicy>
+void SplayTree<Config, AllocationPolicy>::Splay(const Key& key) {
   if (is_empty())
     return;
   Node dummy_node(Config::kNoKey, Config::NoValue());
   // Create a dummy node.  The use of the dummy node is a bit
   // counter-intuitive: The right child of the dummy node will hold
   // the L tree of the algorithm.  The left child of the dummy node
   // will hold the R tree of the algorithm.  Using a dummy node, left
   // and right will always be nodes and we avoid special cases.
   Node* dummy = &dummy_node;
   Node* left = dummy;
@@ skipping 39 matching lines @@
   }
   // Assemble.
   left->right_ = current->left_;
   right->left_ = current->right_;
   current->left_ = dummy->right_;
   current->right_ = dummy->left_;
   root_ = current;
 }
 
 
-template <typename Config, class Allocator> template <class Callback>
-void SplayTree<Config, Allocator>::ForEach(Callback* callback) {
+template <typename Config, class AllocationPolicy> template <class Callback>
+void SplayTree<Config, AllocationPolicy>::ForEach(Callback* callback) {
   NodeToPairAdaptor<Callback> callback_adaptor(callback);
   ForEachNode(&callback_adaptor);
 }
 
 
-template <typename Config, class Allocator> template <class Callback>
-void SplayTree<Config, Allocator>::ForEachNode(Callback* callback) {
+template <typename Config, class AllocationPolicy> template <class Callback>
+void SplayTree<Config, AllocationPolicy>::ForEachNode(Callback* callback,
+                                                      Allocator allocator) {
   // Pre-allocate some space for tiny trees.
-  List<Node*, Allocator> nodes_to_visit(10);
-  if (root_ != NULL) nodes_to_visit.Add(root_);
+  List<Node*, AllocationPolicy> nodes_to_visit(10);
+  if (root_ != NULL) nodes_to_visit.Add(root_, allocator);
   int pos = 0;
   while (pos < nodes_to_visit.length()) {
     Node* node = nodes_to_visit[pos++];
-    if (node->left() != NULL) nodes_to_visit.Add(node->left());
-    if (node->right() != NULL) nodes_to_visit.Add(node->right());
+    if (node->left() != NULL) nodes_to_visit.Add(node->left(), allocator);
+    if (node->right() != NULL) nodes_to_visit.Add(node->right(), allocator);
     callback->Call(node);
   }
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_SPLAY_TREE_INL_H_