Parametrize C++ splay tree with allocator.

src/zone-inl.h

Index: src/zone-inl.h
diff --git a/src/zone-inl.h b/src/zone-inl.h
index 121ba19b12e2cf08ece1e703540d2bc4c3453171..5893a2f80ebbe97178e199a127049d53ae4eac77 100644
--- a/src/zone-inl.h
+++ b/src/zone-inl.h
@@ -68,227 +68,12 @@ void Zone::adjust_segment_bytes_allocated(int delta) {
 }
 
 
-template <typename C>
-bool ZoneSplayTree<C>::Insert(const Key& key, Locator* locator) {
-  if (is_empty()) {
-    // If the tree is empty, insert the new node.
-    root_ = new Node(key, C::kNoValue);
-  } 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 = C::Compare(key, root_->key_);
-    if (cmp == 0) {
-      locator->bind(root_);
-      return false;
-    }
-    // Insert the new node.
-    Node* node = new Node(key, C::kNoValue);
-    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;
-  }
-  locator->bind(root_);
-  return true;
-}
-
-
-template <typename C>
-bool ZoneSplayTree<C>::Find(const Key& key, Locator* locator) {
-  if (is_empty())
-    return false;
-  Splay(key);
-  if (C::Compare(key, root_->key_) == 0) {
-    locator->bind(root_);
-    return true;
-  } else {
-    return false;
-  }
-}
-
-
-template <typename C>
-bool ZoneSplayTree<C>::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 = C::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 C>
-bool ZoneSplayTree<C>::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 = C::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 C>
-bool ZoneSplayTree<C>::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 C>
-bool ZoneSplayTree<C>::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 C>
-bool ZoneSplayTree<C>::Remove(const Key& key) {
-  // Bail if the tree is empty
-  if (is_empty())
-    return false;
-  // Splay on the key to move the node with the given key to the top.
-  Splay(key);
-  // Bail if the key is not in the tree
-  if (C::Compare(key, root_->key_) != 0)
-    return false;
-  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;
-  }
-  return true;
-}
-
-
-template <typename C>
-void ZoneSplayTree<C>::Splay(const Key& key) {
-  if (is_empty())
-    return;
-  Node dummy_node(C::kNoKey, C::kNoValue);
-  // 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;
-  Node* right = dummy;
-  Node* current = root_;
-  while (true) {
-    int cmp = C::Compare(key, current->key_);
-    if (cmp < 0) {
-      if (current->left_ == NULL)
-        break;
-      if (C::Compare(key, current->left_->key_) < 0) {
-        // Rotate right.
-        Node* temp = current->left_;
-        current->left_ = temp->right_;
-        temp->right_ = current;
-        current = temp;
-        if (current->left_ == NULL)
-          break;
-      }
-      // Link right.
-      right->left_ = current;
-      right = current;
-      current = current->left_;
-    } else if (cmp > 0) {
-      if (current->right_ == NULL)
-        break;
-      if (C::Compare(key, current->right_->key_) > 0) {
-        // Rotate left.
-        Node* temp = current->right_;
-        current->right_ = temp->left_;
-        temp->left_ = current;
-        current = temp;
-        if (current->right_ == NULL)
-          break;
-      }
-      // Link left.
-      left->right_ = current;
-      left = current;
-      current = current->right_;
-    } else {
-      break;
-    }
-  }
-  // Assemble.
-  left->right_ = current->left_;
-  right->left_ = current->right_;
-  current->left_ = dummy->right_;
-  current->right_ = dummy->left_;
-  root_ = current;
-}
-
-
-template <typename Config> template <class Callback>
-void ZoneSplayTree<Config>::ForEach(Callback* callback) {
-  // Pre-allocate some space for tiny trees.
-  ZoneList<Node*> nodes_to_visit(10);
-  nodes_to_visit.Add(root_);
-  int pos = 0;
-  while (pos < nodes_to_visit.length()) {
-    Node* node = nodes_to_visit[pos++];
-    if (node == NULL) continue;
-    callback->Call(node->key(), node->value());
-    nodes_to_visit.Add(node->left());
-    nodes_to_visit.Add(node->right());
-  }
+template <typename Config>
+ZoneSplayTree<Config>::~ZoneSplayTree() {
+  // Reset the root to avoid unneeded iteration over all tree nodes
+  // in the destructor.  For a zone-allocated tree, nodes will be
+  // freed by the Zone.
+  SplayTree<Config, ZoneListAllocationPolicy>::ResetRoot();
 }