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 6 * met: 7 * 8 * * Redistributions of source code must retain the above copyright 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, 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#include "config.h" 32 33#include "MutationObserver.h" 34 35#include "Dictionary.h" 36#include "Document.h" 37#include "ExceptionCode.h" 38#include "MutationCallback.h" 39#include "MutationObserverRegistration.h" 40#include "MutationRecord.h" 41#include "Node.h" 42#include <algorithm> 43#include <wtf/HashSet.h> 44#include <wtf/MainThread.h> 45#include <wtf/Vector.h> 46 47namespace WebCore { 48 49static unsigned s_observerPriority = 0; 50 51struct MutationObserver::ObserverLessThan { 52 bool operator()(const RefPtr<MutationObserver>& lhs, const RefPtr<MutationObserver>& rhs) 53 { 54 return lhs->m_priority < rhs->m_priority; 55 } 56}; 57 58PassRefPtr<MutationObserver> MutationObserver::create(PassRefPtr<MutationCallback> callback) 59{ 60 ASSERT(isMainThread()); 61 return adoptRef(new MutationObserver(callback)); 62} 63 64MutationObserver::MutationObserver(PassRefPtr<MutationCallback> callback) 65 : m_callback(callback) 66 , m_priority(s_observerPriority++) 67{ 68} 69 70MutationObserver::~MutationObserver() 71{ 72 ASSERT(m_registrations.isEmpty()); 73} 74 75bool MutationObserver::validateOptions(MutationObserverOptions options) 76{ 77 return (options & (Attributes | CharacterData | ChildList)) 78 && ((options & Attributes) || !(options & AttributeOldValue)) 79 && ((options & Attributes) || !(options & AttributeFilter)) 80 && ((options & CharacterData) || !(options & CharacterDataOldValue)); 81} 82 83void MutationObserver::observe(Node* node, const Dictionary& optionsDictionary, ExceptionCode& ec) 84{ 85 if (!node) { 86 ec = NOT_FOUND_ERR; 87 return; 88 } 89 90 static const struct { 91 const char* name; 92 MutationObserverOptions value; 93 } booleanOptions[] = { 94 { "childList", ChildList }, 95 { "attributes", Attributes }, 96 { "characterData", CharacterData }, 97 { "subtree", Subtree }, 98 { "attributeOldValue", AttributeOldValue }, 99 { "characterDataOldValue", CharacterDataOldValue } 100 }; 101 MutationObserverOptions options = 0; 102 for (unsigned i = 0; i < sizeof(booleanOptions) / sizeof(booleanOptions[0]); ++i) { 103 bool value = false; 104 if (optionsDictionary.get(booleanOptions[i].name, value) && value) 105 options |= booleanOptions[i].value; 106 } 107 108 HashSet<AtomicString> attributeFilter; 109 if (optionsDictionary.get("attributeFilter", attributeFilter)) 110 options |= AttributeFilter; 111 112 if (!validateOptions(options)) { 113 ec = SYNTAX_ERR; 114 return; 115 } 116 117 node->registerMutationObserver(this, options, attributeFilter); 118} 119 120Vector<RefPtr<MutationRecord> > MutationObserver::takeRecords() 121{ 122 Vector<RefPtr<MutationRecord> > records; 123 records.swap(m_records); 124 return records; 125} 126 127void MutationObserver::disconnect() 128{ 129 m_records.clear(); 130 HashSet<MutationObserverRegistration*> registrations(m_registrations); 131 for (HashSet<MutationObserverRegistration*>::iterator iter = registrations.begin(); iter != registrations.end(); ++iter) 132 MutationObserverRegistration::unregisterAndDelete(*iter); 133} 134 135void MutationObserver::observationStarted(MutationObserverRegistration* registration) 136{ 137 ASSERT(!m_registrations.contains(registration)); 138 m_registrations.add(registration); 139} 140 141void MutationObserver::observationEnded(MutationObserverRegistration* registration) 142{ 143 ASSERT(m_registrations.contains(registration)); 144 m_registrations.remove(registration); 145} 146 147typedef HashSet<RefPtr<MutationObserver> > MutationObserverSet; 148 149static MutationObserverSet& activeMutationObservers() 150{ 151 DEFINE_STATIC_LOCAL(MutationObserverSet, activeObservers, ()); 152 return activeObservers; 153} 154 155static MutationObserverSet& suspendedMutationObservers() 156{ 157 DEFINE_STATIC_LOCAL(MutationObserverSet, suspendedObservers, ()); 158 return suspendedObservers; 159} 160 161void MutationObserver::enqueueMutationRecord(PassRefPtr<MutationRecord> mutation) 162{ 163 ASSERT(isMainThread()); 164 m_records.append(mutation); 165 activeMutationObservers().add(this); 166} 167 168void MutationObserver::setHasTransientRegistration() 169{ 170 ASSERT(isMainThread()); 171 activeMutationObservers().add(this); 172} 173 174HashSet<Node*> MutationObserver::getObservedNodes() const 175{ 176 HashSet<Node*> observedNodes; 177 for (HashSet<MutationObserverRegistration*>::const_iterator iter = m_registrations.begin(); iter != m_registrations.end(); ++iter) 178 (*iter)->addRegistrationNodesToSet(observedNodes); 179 return observedNodes; 180} 181 182bool MutationObserver::canDeliver() 183{ 184 return !m_callback->scriptExecutionContext()->activeDOMObjectsAreSuspended(); 185} 186 187void MutationObserver::deliver() 188{ 189 ASSERT(canDeliver()); 190 191 // Calling clearTransientRegistrations() can modify m_registrations, so it's necessary 192 // to make a copy of the transient registrations before operating on them. 193 Vector<MutationObserverRegistration*, 1> transientRegistrations; 194 for (HashSet<MutationObserverRegistration*>::iterator iter = m_registrations.begin(); iter != m_registrations.end(); ++iter) { 195 if ((*iter)->hasTransientRegistrations()) 196 transientRegistrations.append(*iter); 197 } 198 for (size_t i = 0; i < transientRegistrations.size(); ++i) 199 transientRegistrations[i]->clearTransientRegistrations(); 200 201 if (m_records.isEmpty()) 202 return; 203 204 Vector<RefPtr<MutationRecord> > records; 205 records.swap(m_records); 206 207 m_callback->call(records, this); 208} 209 210void MutationObserver::deliverAllMutations() 211{ 212 ASSERT(isMainThread()); 213 static bool deliveryInProgress = false; 214 if (deliveryInProgress) 215 return; 216 deliveryInProgress = true; 217 218 if (!suspendedMutationObservers().isEmpty()) { 219 Vector<RefPtr<MutationObserver> > suspended; 220 copyToVector(suspendedMutationObservers(), suspended); 221 for (size_t i = 0; i < suspended.size(); ++i) { 222 if (!suspended[i]->canDeliver()) 223 continue; 224 225 suspendedMutationObservers().remove(suspended[i]); 226 activeMutationObservers().add(suspended[i]); 227 } 228 } 229 230 while (!activeMutationObservers().isEmpty()) { 231 Vector<RefPtr<MutationObserver> > observers; 232 copyToVector(activeMutationObservers(), observers); 233 activeMutationObservers().clear(); 234 std::sort(observers.begin(), observers.end(), ObserverLessThan()); 235 for (size_t i = 0; i < observers.size(); ++i) { 236 if (observers[i]->canDeliver()) 237 observers[i]->deliver(); 238 else 239 suspendedMutationObservers().add(observers[i]); 240 } 241 } 242 243 deliveryInProgress = false; 244} 245 246} // namespace WebCore 247