| /* |
| * Copyright (C) 2013 Google 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: |
| * |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * 2. 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. |
| * 3. 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_CUSTOM_V0_CUSTOM_ELEMENT_PROCESSING_STACK_H_ |
| #define THIRD_PARTY_BLINK_RENDERER_CORE_HTML_CUSTOM_V0_CUSTOM_ELEMENT_PROCESSING_STACK_H_ |
| |
| #include "base/macros.h" |
| #include "third_party/blink/renderer/core/core_export.h" |
| #include "third_party/blink/renderer/core/html/custom/v0_custom_element_callback_queue.h" |
| #include "third_party/blink/renderer/platform/wtf/vector.h" |
| |
| namespace blink { |
| |
| class CORE_EXPORT V0CustomElementProcessingStack |
| : public GarbageCollected<V0CustomElementProcessingStack> { |
| public: |
| // This is stack allocated in many DOM callbacks. Make it cheap. |
| class CallbackDeliveryScope { |
| STACK_ALLOCATED(); |
| |
| public: |
| CallbackDeliveryScope() : saved_element_queue_start_(element_queue_start_) { |
| element_queue_start_ = element_queue_end_; |
| } |
| |
| ~CallbackDeliveryScope() { |
| if (element_queue_start_ != element_queue_end_) |
| ProcessElementQueueAndPop(); |
| element_queue_start_ = saved_element_queue_start_; |
| } |
| |
| private: |
| wtf_size_t saved_element_queue_start_; |
| }; |
| |
| static bool InCallbackDeliveryScope() { return element_queue_start_; } |
| |
| static V0CustomElementProcessingStack& Instance(); |
| void Enqueue(V0CustomElementCallbackQueue*); |
| |
| void Trace(blink::Visitor*); |
| |
| private: |
| V0CustomElementProcessingStack() { |
| // Add a null element as a sentinel. This makes it possible to |
| // identify elements queued when there is no |
| // CallbackDeliveryScope active. Also, if the processing stack |
| // is popped when empty, this sentinel will cause a null deref |
| // crash. |
| V0CustomElementCallbackQueue* sentinel = nullptr; |
| for (wtf_size_t i = 0; i < kNumSentinels; i++) |
| flattened_processing_stack_.push_back(sentinel); |
| DCHECK_EQ(element_queue_end_, flattened_processing_stack_.size()); |
| } |
| |
| // The start of the element queue on the top of the processing |
| // stack. An offset into Instance().flattened_processing_stack_. |
| static wtf_size_t element_queue_start_; |
| |
| // The end of the element queue on the top of the processing |
| // stack. A cache of Instance().flattened_processing_stack_.size(). |
| static wtf_size_t element_queue_end_; |
| |
| static V0CustomElementCallbackQueue::ElementQueueId CurrentElementQueue() { |
| return V0CustomElementCallbackQueue::ElementQueueId(element_queue_start_); |
| } |
| |
| static void ProcessElementQueueAndPop(); |
| void ProcessElementQueueAndPop(wtf_size_t start, wtf_size_t end); |
| |
| // The processing stack, flattened. Element queues lower in the |
| // stack appear toward the head of the vector. The first element |
| // is a null sentinel value. |
| static const wtf_size_t kNumSentinels = 1; |
| HeapVector<Member<V0CustomElementCallbackQueue>> flattened_processing_stack_; |
| |
| DISALLOW_COPY_AND_ASSIGN(V0CustomElementProcessingStack); |
| }; |
| |
| } // namespace blink |
| |
| #endif // THIRD_PARTY_BLINK_RENDERER_CORE_HTML_CUSTOM_V0_CUSTOM_ELEMENT_PROCESSING_STACK_H_ |