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