// Copyright 2006-2008 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
// with the distribution.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived
// from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#ifndef V8_ZONE_INL_H_
#define V8_ZONE_INL_H_
#include "zone.h"
#include "v8-counters.h"
namespace v8 {
namespace internal {
inline void* Zone::New(int size) {
ASSERT(AssertNoZoneAllocation::allow_allocation());
ASSERT(ZoneScope::nesting() > 0);
// Round up the requested size to fit the alignment.
size = RoundUp(size, kAlignment);
// Check if the requested size is available without expanding.
Address result = position_;
if ((position_ += size) > limit_) result = NewExpand(size);
// Check that the result has the proper alignment and return it.
ASSERT(IsAddressAligned(result, kAlignment, 0));
return reinterpret_cast<void*>(result);
}
template <typename T>
T* Zone::NewArray(int length) {
return static_cast<T*>(Zone::New(length * sizeof(T)));
}
bool Zone::excess_allocation() {
return segment_bytes_allocated_ > zone_excess_limit_;
}
void Zone::adjust_segment_bytes_allocated(int delta) {
segment_bytes_allocated_ += delta;
Counters::zone_segment_bytes.Set(segment_bytes_allocated_);
}
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());
}
}
} } // namespace v8::internal
#endif // V8_ZONE_INL_H_