OLD | NEW |
| (Empty) |
1 /* | |
2 * Copyright (C) 2013 Google Inc. All rights reserved. | |
3 * | |
4 * Redistribution and use in source and binary forms, with or without | |
5 * modification, are permitted provided that the following conditions | |
6 * are met: | |
7 * | |
8 * 1. Redistributions of source code must retain the above copyright | |
9 * notice, this list of conditions and the following disclaimer. | |
10 * 2. Redistributions in binary form must reproduce the above copyright | |
11 * notice, this list of conditions and the following disclaimer | |
12 * in the documentation and/or other materials provided with the | |
13 * distribution. | |
14 * 3. Neither the name of Google Inc. nor the names of its contributors | |
15 * may be used to endorse or promote products derived from this | |
16 * software without specific prior written permission. | |
17 * | |
18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS | |
19 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT | |
20 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR | |
21 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT | |
22 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, | |
23 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT | |
24 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, | |
25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY | |
26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT | |
27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE | |
28 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | |
29 */ | |
30 | |
31 #ifndef CustomElementProcessingStack_h | |
32 #define CustomElementProcessingStack_h | |
33 | |
34 #include "core/CoreExport.h" | |
35 #include "core/dom/custom/CustomElementCallbackQueue.h" | |
36 #include "wtf/Vector.h" | |
37 | |
38 namespace blink { | |
39 | |
40 class CORE_EXPORT CustomElementProcessingStack : public GarbageCollectedFinalize
d<CustomElementProcessingStack> { | |
41 WTF_MAKE_NONCOPYABLE(CustomElementProcessingStack); | |
42 public: | |
43 // This is stack allocated in many DOM callbacks. Make it cheap. | |
44 class CallbackDeliveryScope { | |
45 STACK_ALLOCATED(); | |
46 public: | |
47 CallbackDeliveryScope() | |
48 : m_savedElementQueueStart(s_elementQueueStart) | |
49 { | |
50 s_elementQueueStart = s_elementQueueEnd; | |
51 } | |
52 | |
53 ~CallbackDeliveryScope() | |
54 { | |
55 if (s_elementQueueStart != s_elementQueueEnd) | |
56 processElementQueueAndPop(); | |
57 s_elementQueueStart = m_savedElementQueueStart; | |
58 } | |
59 | |
60 private: | |
61 size_t m_savedElementQueueStart; | |
62 }; | |
63 | |
64 static bool inCallbackDeliveryScope() { return s_elementQueueStart; } | |
65 | |
66 static CustomElementProcessingStack& instance(); | |
67 void enqueue(CustomElementCallbackQueue*); | |
68 | |
69 DECLARE_TRACE(); | |
70 | |
71 private: | |
72 CustomElementProcessingStack() | |
73 { | |
74 // Add a null element as a sentinel. This makes it possible to | |
75 // identify elements queued when there is no | |
76 // CallbackDeliveryScope active. Also, if the processing stack | |
77 // is popped when empty, this sentinel will cause a null deref | |
78 // crash. | |
79 CustomElementCallbackQueue* sentinel = 0; | |
80 for (size_t i = 0; i < kNumSentinels; i++) | |
81 m_flattenedProcessingStack.append(sentinel); | |
82 DCHECK_EQ(s_elementQueueEnd, m_flattenedProcessingStack.size()); | |
83 } | |
84 | |
85 // The start of the element queue on the top of the processing | |
86 // stack. An offset into instance().m_flattenedProcessingStack. | |
87 static size_t s_elementQueueStart; | |
88 | |
89 // The end of the element queue on the top of the processing | |
90 // stack. A cache of instance().m_flattenedProcessingStack.size(). | |
91 static size_t s_elementQueueEnd; | |
92 | |
93 static CustomElementCallbackQueue::ElementQueueId currentElementQueue() { re
turn CustomElementCallbackQueue::ElementQueueId(s_elementQueueStart); } | |
94 | |
95 static void processElementQueueAndPop(); | |
96 void processElementQueueAndPop(size_t start, size_t end); | |
97 | |
98 // The processing stack, flattened. Element queues lower in the | |
99 // stack appear toward the head of the vector. The first element | |
100 // is a null sentinel value. | |
101 static const size_t kNumSentinels = 1; | |
102 HeapVector<Member<CustomElementCallbackQueue>> m_flattenedProcessingStack; | |
103 }; | |
104 | |
105 } // namespace blink | |
106 | |
107 #endif // CustomElementProcessingStack_h | |
OLD | NEW |