third_party/WebKit/Source/core/dom/MutationObserver.cpp

   1 /*
   2  * Copyright (C) 2011 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 are
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   7  *
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   9  * notice, this list of conditions and the following disclaimer.
  10  *     * Redistributions in binary form must reproduce the above
  11  * copyright notice, this list of conditions and the following disclaimer
  12  * in the documentation and/or other materials provided with the
  13  * distribution.
  14  *     * Neither the name of Google Inc. nor the names of its
  15  * contributors may be used to endorse or promote products derived from
  16  * this 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,
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  26  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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  28  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  29  */
  30
  31 #include "config.h"
  32 #include "core/dom/MutationObserver.h"
  33
  34 #include "bindings/core/v8/ExceptionState.h"
  35 #include "core/dom/ExceptionCode.h"
  36 #include "core/dom/Microtask.h"
  37 #include "core/dom/MutationCallback.h"
  38 #include "core/dom/MutationObserverInit.h"
  39 #include "core/dom/MutationObserverRegistration.h"
  40 #include "core/dom/MutationRecord.h"
  41 #include "core/dom/Node.h"
  42 #include "core/inspector/InspectorInstrumentation.h"
  43 #include "wtf/MainThread.h"
  44 #include <algorithm>
  45
  46 namespace blink {
  47
  48 static unsigned s_observerPriority = 0;
  49
  50 struct MutationObserver::ObserverLessThan {
  51     bool operator()(const RefPtrWillBeMember<MutationObserver>& lhs, const RefPtrWillBeMember<MutationObserver>& rhs)
  52     {
  53         return lhs->m_priority < rhs->m_priority;
  54     }
  55 };
  56
  57 PassRefPtrWillBeRawPtr<MutationObserver> MutationObserver::create(PassOwnPtrWillBeRawPtr<MutationCallback> callback)
  58 {
  59     ASSERT(isMainThread());
  60     return adoptRefWillBeNoop(new MutationObserver(callback));
  61 }
  62
  63 MutationObserver::MutationObserver(PassOwnPtrWillBeRawPtr<MutationCallback> callback)
  64     : m_callback(callback)
  65     , m_priority(s_observerPriority++)
  66 {
  67 }
  68
  69 MutationObserver::~MutationObserver()
  70 {
  71 #if !ENABLE(OILPAN)
  72     ASSERT(m_registrations.isEmpty());
  73 #endif
  74     if (!m_records.isEmpty())
  75         InspectorInstrumentation::didClearAllMutationRecords(m_callback->executionContext(), this);
  76 }
  77
  78 void MutationObserver::observe(Node* node, const MutationObserverInit& observerInit, ExceptionState& exceptionState)
  79 {
  80     if (!node) {
  81         exceptionState.throwDOMException(NotFoundError, "The provided node was null.");
  82         return;
  83     }
  84
  85     MutationObserverOptions options = 0;
  86
  87     if (observerInit.hasAttributeOldValue() && observerInit.attributeOldValue())
  88         options |= AttributeOldValue;
  89
  90     HashSet<AtomicString> attributeFilter;
  91     if (observerInit.hasAttributeFilter()) {
  92         const Vector<String>& sequence = observerInit.attributeFilter();
  93         for (unsigned i = 0; i < sequence.size(); ++i)
  94             attributeFilter.add(AtomicString(sequence[i]));
  95         options |= AttributeFilter;
  96     }
  97
  98     bool attributes = observerInit.hasAttributes() && observerInit.attributes();
  99     if (attributes || (!observerInit.hasAttributes() && (observerInit.hasAttributeOldValue() || observerInit.hasAttributeFilter())))
 100         options |= Attributes;
 101
 102     if (observerInit.hasCharacterDataOldValue() && observerInit.characterDataOldValue())
 103         options |= CharacterDataOldValue;
 104
 105     bool characterData = observerInit.hasCharacterData() && observerInit.characterData();
 106     if (characterData || (!observerInit.hasCharacterData() && observerInit.hasCharacterDataOldValue()))
 107         options |= CharacterData;
 108
 109     if (observerInit.childList())
 110         options |= ChildList;
 111
 112     if (observerInit.subtree())
 113         options |= Subtree;
 114
 115     if (!(options & Attributes)) {
 116         if (options & AttributeOldValue) {
 117             exceptionState.throwTypeError("The options object may only set 'attributeOldValue' to true when 'attributes' is true or not present.");
 118             return;
 119         }
 120         if (options & AttributeFilter) {
 121             exceptionState.throwTypeError("The options object may only set 'attributeFilter' when 'attributes' is true or not present.");
 122             return;
 123         }
 124     }
 125     if (!((options & CharacterData) || !(options & CharacterDataOldValue))) {
 126         exceptionState.throwTypeError("The options object may only set 'characterDataOldValue' to true when 'characterData' is true or not present.");
 127         return;
 128     }
 129
 130     if (!(options & (Attributes | CharacterData | ChildList))) {
 131         exceptionState.throwTypeError("The options object must set at least one of 'attributes', 'characterData', or 'childList' to true.");
 132         return;
 133     }
 134
 135     node->registerMutationObserver(*this, options, attributeFilter);
 136 }
 137
 138 MutationRecordVector MutationObserver::takeRecords()
 139 {
 140     MutationRecordVector records;
 141     records.swap(m_records);
 142     InspectorInstrumentation::didClearAllMutationRecords(m_callback->executionContext(), this);
 143     return records;
 144 }
 145
 146 void MutationObserver::disconnect()
 147 {
 148     m_records.clear();
 149     InspectorInstrumentation::didClearAllMutationRecords(m_callback->executionContext(), this);
 150     MutationObserverRegistrationSet registrations(m_registrations);
 151     for (auto& registration : registrations) {
 152         // The registration may be already unregistered while iteration.
 153         // Only call unregister if it is still in the original set.
 154         if (m_registrations.contains(registration))
 155             registration->unregister();
 156     }
 157     ASSERT(m_registrations.isEmpty());
 158 }
 159
 160 void MutationObserver::observationStarted(MutationObserverRegistration* registration)
 161 {
 162     ASSERT(!m_registrations.contains(registration));
 163     m_registrations.add(registration);
 164 }
 165
 166 void MutationObserver::observationEnded(MutationObserverRegistration* registration)
 167 {
 168     ASSERT(m_registrations.contains(registration));
 169     m_registrations.remove(registration);
 170 }
 171
 172 static MutationObserverSet& activeMutationObservers()
 173 {
 174     DEFINE_STATIC_LOCAL(OwnPtrWillBePersistent<MutationObserverSet>, activeObservers, (adoptPtrWillBeNoop(new MutationObserverSet())));
 175     return *activeObservers;
 176 }
 177
 178 static MutationObserverSet& suspendedMutationObservers()
 179 {
 180     DEFINE_STATIC_LOCAL(OwnPtrWillBePersistent<MutationObserverSet>, suspendedObservers, (adoptPtrWillBeNoop(new MutationObserverSet())));
 181     return *suspendedObservers;
 182 }
 183
 184 static void activateObserver(PassRefPtrWillBeRawPtr<MutationObserver> observer)
 185 {
 186     if (activeMutationObservers().isEmpty())
 187         Microtask::enqueueMicrotask(WTF::bind(&MutationObserver::deliverMutations));
 188
 189     activeMutationObservers().add(observer);
 190 }
 191
 192 void MutationObserver::enqueueMutationRecord(PassRefPtrWillBeRawPtr<MutationRecord> mutation)
 193 {
 194     ASSERT(isMainThread());
 195     m_records.append(mutation);
 196     activateObserver(this);
 197     InspectorInstrumentation::didEnqueueMutationRecord(m_callback->executionContext(), this);
 198 }
 199
 200 void MutationObserver::setHasTransientRegistration()
 201 {
 202     ASSERT(isMainThread());
 203     activateObserver(this);
 204 }
 205
 206 WillBeHeapHashSet<RawPtrWillBeMember<Node>> MutationObserver::getObservedNodes() const
 207 {
 208     WillBeHeapHashSet<RawPtrWillBeMember<Node>> observedNodes;
 209     for (const auto& registration : m_registrations)
 210         registration->addRegistrationNodesToSet(observedNodes);
 211     return observedNodes;
 212 }
 213
 214 bool MutationObserver::shouldBeSuspended() const
 215 {
 216     return m_callback->executionContext() && m_callback->executionContext()->activeDOMObjectsAreSuspended();
 217 }
 218
 219 void MutationObserver::deliver()
 220 {
 221     ASSERT(!shouldBeSuspended());
 222
 223     // Calling clearTransientRegistrations() can modify m_registrations, so it's necessary
 224     // to make a copy of the transient registrations before operating on them.
 225     WillBeHeapVector<RawPtrWillBeMember<MutationObserverRegistration>, 1> transientRegistrations;
 226     for (auto& registration : m_registrations) {
 227         if (registration->hasTransientRegistrations())
 228             transientRegistrations.append(registration);
 229     }
 230     for (size_t i = 0; i < transientRegistrations.size(); ++i)
 231         transientRegistrations[i]->clearTransientRegistrations();
 232
 233     if (m_records.isEmpty())
 234         return;
 235
 236     MutationRecordVector records;
 237     records.swap(m_records);
 238
 239     InspectorInstrumentation::willDeliverMutationRecords(m_callback->executionContext(), this);
 240     m_callback->call(records, this);
 241     InspectorInstrumentation::didDeliverMutationRecords(m_callback->executionContext());
 242 }
 243
 244 void MutationObserver::resumeSuspendedObservers()
 245 {
 246     ASSERT(isMainThread());
 247     if (suspendedMutationObservers().isEmpty())
 248         return;
 249
 250     MutationObserverVector suspended;
 251     copyToVector(suspendedMutationObservers(), suspended);
 252     for (size_t i = 0; i < suspended.size(); ++i) {
 253         if (!suspended[i]->shouldBeSuspended()) {
 254             suspendedMutationObservers().remove(suspended[i]);
 255             activateObserver(suspended[i]);
 256         }
 257     }
 258 }
 259
 260 void MutationObserver::deliverMutations()
 261 {
 262     ASSERT(isMainThread());
 263     MutationObserverVector observers;
 264     copyToVector(activeMutationObservers(), observers);
 265     activeMutationObservers().clear();
 266     std::sort(observers.begin(), observers.end(), ObserverLessThan());
 267     for (size_t i = 0; i < observers.size(); ++i) {
 268         if (observers[i]->shouldBeSuspended())
 269             suspendedMutationObservers().add(observers[i]);
 270         else
 271             observers[i]->deliver();
 272     }
 273 }
 274
 275 DEFINE_TRACE(MutationObserver)
 276 {
 277 #if ENABLE(OILPAN)
 278     visitor->trace(m_callback);
 279     visitor->trace(m_records);
 280     visitor->trace(m_registrations);
 281     visitor->trace(m_callback);
 282 #endif
 283 }
 284
 285 } // namespace blink