| /* |
| * Copyright (C) 2012,2013 Google Inc. All rights reserved. |
| * Copyright (C) 2014 Apple Inc. 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 |
| * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| */ |
| |
| #ifndef THIRD_PARTY_BLINK_RENDERER_CORE_HTML_COLLECTION_ITEMS_CACHE_H_ |
| #define THIRD_PARTY_BLINK_RENDERER_CORE_HTML_COLLECTION_ITEMS_CACHE_H_ |
| |
| #include "third_party/blink/renderer/core/dom/collection_index_cache.h" |
| #include "third_party/blink/renderer/platform/wtf/vector.h" |
| |
| namespace blink { |
| |
| template <typename Collection, typename NodeType> |
| class CollectionItemsCache : public CollectionIndexCache<Collection, NodeType> { |
| DISALLOW_NEW(); |
| |
| typedef CollectionIndexCache<Collection, NodeType> Base; |
| |
| public: |
| CollectionItemsCache(); |
| ~CollectionItemsCache(); |
| |
| void Trace(blink::Visitor* visitor) override { |
| visitor->Trace(cached_list_); |
| Base::Trace(visitor); |
| } |
| |
| unsigned NodeCount(const Collection&); |
| NodeType* NodeAt(const Collection&, unsigned index); |
| void Invalidate(); |
| |
| private: |
| bool list_valid_; |
| HeapVector<Member<NodeType>> cached_list_; |
| }; |
| |
| template <typename Collection, typename NodeType> |
| CollectionItemsCache<Collection, NodeType>::CollectionItemsCache() |
| : list_valid_(false) {} |
| |
| template <typename Collection, typename NodeType> |
| CollectionItemsCache<Collection, NodeType>::~CollectionItemsCache() = default; |
| |
| template <typename Collection, typename NodeType> |
| void CollectionItemsCache<Collection, NodeType>::Invalidate() { |
| Base::Invalidate(); |
| if (list_valid_) { |
| cached_list_.Shrink(0); |
| list_valid_ = false; |
| } |
| } |
| |
| template <class Collection, class NodeType> |
| unsigned CollectionItemsCache<Collection, NodeType>::NodeCount( |
| const Collection& collection) { |
| if (this->IsCachedNodeCountValid()) |
| return this->CachedNodeCount(); |
| |
| NodeType* current_node = collection.TraverseToFirst(); |
| unsigned current_index = 0; |
| while (current_node) { |
| cached_list_.push_back(current_node); |
| current_node = collection.TraverseForwardToOffset( |
| current_index + 1, *current_node, current_index); |
| } |
| |
| this->SetCachedNodeCount(cached_list_.size()); |
| list_valid_ = true; |
| return this->CachedNodeCount(); |
| } |
| |
| template <typename Collection, typename NodeType> |
| inline NodeType* CollectionItemsCache<Collection, NodeType>::NodeAt( |
| const Collection& collection, |
| unsigned index) { |
| if (list_valid_) { |
| DCHECK(this->IsCachedNodeCountValid()); |
| return index < this->CachedNodeCount() ? cached_list_[index] : nullptr; |
| } |
| return Base::NodeAt(collection, index); |
| } |
| |
| } // namespace blink |
| |
| #endif // THIRD_PARTY_BLINK_RENDERER_CORE_HTML_COLLECTION_ITEMS_CACHE_H_ |