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32 #include "core/inspector/DOMPatchSupport.h"
34 #include "bindings/v8/ExceptionState.h"
35 #include "bindings/v8/ExceptionStatePlaceholder.h"
36 #include "core/dom/Attribute.h"
37 #include "core/dom/ContextFeatures.h"
38 #include "core/dom/Document.h"
39 #include "core/dom/DocumentFragment.h"
40 #include "core/dom/Node.h"
41 #include "core/dom/XMLDocument.h"
42 #include "core/html/HTMLBodyElement.h"
43 #include "core/html/HTMLDocument.h"
44 #include "core/html/HTMLHeadElement.h"
45 #include "core/html/parser/HTMLDocumentParser.h"
46 #include "core/inspector/DOMEditor.h"
47 #include "core/inspector/InspectorHistory.h"
48 #include "core/xml/parser/XMLDocumentParser.h"
49 #include "platform/Crypto.h"
50 #include "public/platform/Platform.h"
51 #include "wtf/Deque.h"
52 #include "wtf/HashTraits.h"
53 #include "wtf/RefPtr.h"
54 #include "wtf/text/Base64.h"
55 #include "wtf/text/CString.h"
61 struct DOMPatchSupport::Digest {
62 explicit Digest(Node* node) : m_node(node) { }
67 Vector<OwnPtr<Digest> > m_children;
70 void DOMPatchSupport::patchDocument(Document& document, const String& markup)
72 InspectorHistory history;
73 DOMEditor domEditor(&history);
74 DOMPatchSupport patchSupport(&domEditor, document);
75 patchSupport.patchDocument(markup);
78 DOMPatchSupport::DOMPatchSupport(DOMEditor* domEditor, Document& document)
79 : m_domEditor(domEditor)
80 , m_document(document)
84 void DOMPatchSupport::patchDocument(const String& markup)
86 RefPtr<Document> newDocument;
87 if (m_document.isHTMLDocument())
88 newDocument = HTMLDocument::create();
89 else if (m_document.isXHTMLDocument())
90 newDocument = XMLDocument::createXHTML();
91 else if (m_document.isXMLDocument())
92 newDocument = XMLDocument::create();
95 newDocument->setContextFeatures(m_document.contextFeatures());
96 RefPtr<DocumentParser> parser;
97 if (m_document.isHTMLDocument())
98 parser = HTMLDocumentParser::create(toHTMLDocument(newDocument.get()), false);
100 parser = XMLDocumentParser::create(newDocument.get(), 0);
101 parser->insert(markup); // Use insert() so that the parser will not yield.
105 OwnPtr<Digest> oldInfo = createDigest(m_document.documentElement(), 0);
106 OwnPtr<Digest> newInfo = createDigest(newDocument->documentElement(), &m_unusedNodesMap);
108 if (!innerPatchNode(oldInfo.get(), newInfo.get(), IGNORE_EXCEPTION)) {
109 // Fall back to rewrite.
110 m_document.write(markup);
115 Node* DOMPatchSupport::patchNode(Node* node, const String& markup, ExceptionState& exceptionState)
117 // Don't parse <html> as a fragment.
118 if (node->isDocumentNode() || (node->parentNode() && node->parentNode()->isDocumentNode())) {
119 patchDocument(markup);
123 Node* previousSibling = node->previousSibling();
124 RefPtr<DocumentFragment> fragment = DocumentFragment::create(m_document);
125 Node* targetNode = node->parentElementOrShadowRoot() ? node->parentElementOrShadowRoot() : m_document.documentElement();
127 // Use the document BODY as the context element when editing immediate shadow root children,
128 // as it provides an equivalent parsing context.
129 if (targetNode->isShadowRoot())
130 targetNode = m_document.body();
131 Element* targetElement = toElement(targetNode);
133 // FIXME: This code should use one of createFragment* in markup.h
134 if (m_document.isHTMLDocument())
135 fragment->parseHTML(markup, targetElement);
137 fragment->parseXML(markup, targetElement);
139 // Compose the old list.
140 ContainerNode* parentNode = node->parentNode();
141 Vector<OwnPtr<Digest> > oldList;
142 for (Node* child = parentNode->firstChild(); child; child = child->nextSibling())
143 oldList.append(createDigest(child, 0));
145 // Compose the new list.
146 String markupCopy = markup.lower();
147 Vector<OwnPtr<Digest> > newList;
148 for (Node* child = parentNode->firstChild(); child != node; child = child->nextSibling())
149 newList.append(createDigest(child, 0));
150 for (Node* child = fragment->firstChild(); child; child = child->nextSibling()) {
151 if (isHTMLHeadElement(*child) && !child->firstChild() && markupCopy.find("</head>") == kNotFound)
152 continue; // HTML5 parser inserts empty <head> tag whenever it parses <body>
153 if (isHTMLBodyElement(*child) && !child->firstChild() && markupCopy.find("</body>") == kNotFound)
154 continue; // HTML5 parser inserts empty <body> tag whenever it parses </head>
155 newList.append(createDigest(child, &m_unusedNodesMap));
157 for (Node* child = node->nextSibling(); child; child = child->nextSibling())
158 newList.append(createDigest(child, 0));
160 if (!innerPatchChildren(parentNode, oldList, newList, exceptionState)) {
161 // Fall back to total replace.
162 if (!m_domEditor->replaceChild(parentNode, fragment.release(), node, exceptionState))
165 return previousSibling ? previousSibling->nextSibling() : parentNode->firstChild();
168 bool DOMPatchSupport::innerPatchNode(Digest* oldDigest, Digest* newDigest, ExceptionState& exceptionState)
170 if (oldDigest->m_sha1 == newDigest->m_sha1)
173 Node* oldNode = oldDigest->m_node;
174 Node* newNode = newDigest->m_node;
176 if (newNode->nodeType() != oldNode->nodeType() || newNode->nodeName() != oldNode->nodeName())
177 return m_domEditor->replaceChild(oldNode->parentNode(), newNode, oldNode, exceptionState);
179 if (oldNode->nodeValue() != newNode->nodeValue()) {
180 if (!m_domEditor->setNodeValue(oldNode, newNode->nodeValue(), exceptionState))
184 if (oldNode->nodeType() != Node::ELEMENT_NODE)
188 Element* oldElement = toElement(oldNode);
189 Element* newElement = toElement(newNode);
190 if (oldDigest->m_attrsSHA1 != newDigest->m_attrsSHA1) {
191 // FIXME: Create a function in Element for removing all properties. Take in account whether did/willModifyAttribute are important.
192 if (oldElement->hasAttributesWithoutUpdate()) {
193 while (oldElement->attributeCount()) {
194 const Attribute& attribute = oldElement->attributeItem(0);
195 if (!m_domEditor->removeAttribute(oldElement, attribute.localName(), exceptionState))
200 // FIXME: Create a function in Element for copying properties. cloneDataFromElement() is close but not enough for this case.
201 if (newElement->hasAttributesWithoutUpdate()) {
202 size_t numAttrs = newElement->attributeCount();
203 for (size_t i = 0; i < numAttrs; ++i) {
204 const Attribute& attribute = newElement->attributeItem(i);
205 if (!m_domEditor->setAttribute(oldElement, attribute.name().localName(), attribute.value(), exceptionState))
211 bool result = innerPatchChildren(oldElement, oldDigest->m_children, newDigest->m_children, exceptionState);
212 m_unusedNodesMap.remove(newDigest->m_sha1);
216 pair<DOMPatchSupport::ResultMap, DOMPatchSupport::ResultMap>
217 DOMPatchSupport::diff(const Vector<OwnPtr<Digest> >& oldList, const Vector<OwnPtr<Digest> >& newList)
219 ResultMap newMap(newList.size());
220 ResultMap oldMap(oldList.size());
222 for (size_t i = 0; i < oldMap.size(); ++i) {
224 oldMap[i].second = 0;
227 for (size_t i = 0; i < newMap.size(); ++i) {
229 newMap[i].second = 0;
232 // Trim head and tail.
233 for (size_t i = 0; i < oldList.size() && i < newList.size() && oldList[i]->m_sha1 == newList[i]->m_sha1; ++i) {
234 oldMap[i].first = oldList[i].get();
235 oldMap[i].second = i;
236 newMap[i].first = newList[i].get();
237 newMap[i].second = i;
239 for (size_t i = 0; i < oldList.size() && i < newList.size() && oldList[oldList.size() - i - 1]->m_sha1 == newList[newList.size() - i - 1]->m_sha1; ++i) {
240 size_t oldIndex = oldList.size() - i - 1;
241 size_t newIndex = newList.size() - i - 1;
242 oldMap[oldIndex].first = oldList[oldIndex].get();
243 oldMap[oldIndex].second = newIndex;
244 newMap[newIndex].first = newList[newIndex].get();
245 newMap[newIndex].second = oldIndex;
248 typedef HashMap<String, Vector<size_t> > DiffTable;
252 for (size_t i = 0; i < newList.size(); ++i) {
253 newTable.add(newList[i]->m_sha1, Vector<size_t>()).storedValue->value.append(i);
256 for (size_t i = 0; i < oldList.size(); ++i) {
257 oldTable.add(oldList[i]->m_sha1, Vector<size_t>()).storedValue->value.append(i);
260 for (DiffTable::iterator newIt = newTable.begin(); newIt != newTable.end(); ++newIt) {
261 if (newIt->value.size() != 1)
264 DiffTable::iterator oldIt = oldTable.find(newIt->key);
265 if (oldIt == oldTable.end() || oldIt->value.size() != 1)
268 newMap[newIt->value[0]] = make_pair(newList[newIt->value[0]].get(), oldIt->value[0]);
269 oldMap[oldIt->value[0]] = make_pair(oldList[oldIt->value[0]].get(), newIt->value[0]);
272 for (size_t i = 0; newList.size() > 0 && i < newList.size() - 1; ++i) {
273 if (!newMap[i].first || newMap[i + 1].first)
276 size_t j = newMap[i].second + 1;
277 if (j < oldMap.size() && !oldMap[j].first && newList[i + 1]->m_sha1 == oldList[j]->m_sha1) {
278 newMap[i + 1] = make_pair(newList[i + 1].get(), j);
279 oldMap[j] = make_pair(oldList[j].get(), i + 1);
283 for (size_t i = newList.size() - 1; newList.size() > 0 && i > 0; --i) {
284 if (!newMap[i].first || newMap[i - 1].first || newMap[i].second <= 0)
287 size_t j = newMap[i].second - 1;
288 if (!oldMap[j].first && newList[i - 1]->m_sha1 == oldList[j]->m_sha1) {
289 newMap[i - 1] = make_pair(newList[i - 1].get(), j);
290 oldMap[j] = make_pair(oldList[j].get(), i - 1);
294 #ifdef DEBUG_DOM_PATCH_SUPPORT
295 dumpMap(oldMap, "OLD");
296 dumpMap(newMap, "NEW");
299 return make_pair(oldMap, newMap);
302 bool DOMPatchSupport::innerPatchChildren(ContainerNode* parentNode, const Vector<OwnPtr<Digest> >& oldList, const Vector<OwnPtr<Digest> >& newList, ExceptionState& exceptionState)
304 pair<ResultMap, ResultMap> resultMaps = diff(oldList, newList);
305 ResultMap& oldMap = resultMaps.first;
306 ResultMap& newMap = resultMaps.second;
311 // 1. First strip everything except for the nodes that retain. Collect pending merges.
312 HashMap<Digest*, Digest*> merges;
313 HashSet<size_t, WTF::IntHash<size_t>, WTF::UnsignedWithZeroKeyHashTraits<size_t> > usedNewOrdinals;
314 for (size_t i = 0; i < oldList.size(); ++i) {
315 if (oldMap[i].first) {
316 if (usedNewOrdinals.add(oldMap[i].second).isNewEntry)
319 oldMap[i].second = 0;
322 // Always match <head> and <body> tags with each other - we can't remove them from the DOM
324 if (isHTMLHeadElement(*oldList[i]->m_node)) {
325 oldHead = oldList[i].get();
328 if (isHTMLBodyElement(*oldList[i]->m_node)) {
329 oldBody = oldList[i].get();
333 // Check if this change is between stable nodes. If it is, consider it as "modified".
334 if (!m_unusedNodesMap.contains(oldList[i]->m_sha1) && (!i || oldMap[i - 1].first) && (i == oldMap.size() - 1 || oldMap[i + 1].first)) {
335 size_t anchorCandidate = i ? oldMap[i - 1].second + 1 : 0;
336 size_t anchorAfter = (i == oldMap.size() - 1) ? anchorCandidate + 1 : oldMap[i + 1].second;
337 if (anchorAfter - anchorCandidate == 1 && anchorCandidate < newList.size())
338 merges.set(newList[anchorCandidate].get(), oldList[i].get());
340 if (!removeChildAndMoveToNew(oldList[i].get(), exceptionState))
344 if (!removeChildAndMoveToNew(oldList[i].get(), exceptionState))
349 // Mark retained nodes as used, do not reuse node more than once.
350 HashSet<size_t, WTF::IntHash<size_t>, WTF::UnsignedWithZeroKeyHashTraits<size_t> > usedOldOrdinals;
351 for (size_t i = 0; i < newList.size(); ++i) {
352 if (!newMap[i].first)
354 size_t oldOrdinal = newMap[i].second;
355 if (usedOldOrdinals.contains(oldOrdinal)) {
356 // Do not map node more than once
358 newMap[i].second = 0;
361 usedOldOrdinals.add(oldOrdinal);
362 markNodeAsUsed(newMap[i].first);
365 // Mark <head> and <body> nodes for merge.
366 if (oldHead || oldBody) {
367 for (size_t i = 0; i < newList.size(); ++i) {
368 if (oldHead && isHTMLHeadElement(*newList[i]->m_node))
369 merges.set(newList[i].get(), oldHead);
370 if (oldBody && isHTMLBodyElement(*newList[i]->m_node))
371 merges.set(newList[i].get(), oldBody);
375 // 2. Patch nodes marked for merge.
376 for (HashMap<Digest*, Digest*>::iterator it = merges.begin(); it != merges.end(); ++it) {
377 if (!innerPatchNode(it->value, it->key, exceptionState))
381 // 3. Insert missing nodes.
382 for (size_t i = 0; i < newMap.size(); ++i) {
383 if (newMap[i].first || merges.contains(newList[i].get()))
385 if (!insertBeforeAndMarkAsUsed(parentNode, newList[i].get(), parentNode->traverseToChildAt(i), exceptionState))
389 // 4. Then put all nodes that retained into their slots (sort by new index).
390 for (size_t i = 0; i < oldMap.size(); ++i) {
391 if (!oldMap[i].first)
393 RefPtr<Node> node = oldMap[i].first->m_node;
394 Node* anchorNode = parentNode->traverseToChildAt(oldMap[i].second);
395 if (node == anchorNode)
397 if (isHTMLBodyElement(*node) || isHTMLHeadElement(*node))
398 continue; // Never move head or body, move the rest of the nodes around them.
400 if (!m_domEditor->insertBefore(parentNode, node.release(), anchorNode, exceptionState))
406 static void addStringToDigestor(blink::WebCryptoDigestor* digestor, const String& string)
408 digestor->consume(reinterpret_cast<const unsigned char*>(string.utf8().data()), string.length());
411 PassOwnPtr<DOMPatchSupport::Digest> DOMPatchSupport::createDigest(Node* node, UnusedNodesMap* unusedNodesMap)
413 Digest* digest = new Digest(node);
415 OwnPtr<blink::WebCryptoDigestor> digestor = createDigestor(HashAlgorithmSha1);
416 DigestValue digestResult;
418 Node::NodeType nodeType = node->nodeType();
419 digestor->consume(reinterpret_cast<const unsigned char*>(&nodeType), sizeof(nodeType));
420 addStringToDigestor(digestor.get(), node->nodeName());
421 addStringToDigestor(digestor.get(), node->nodeValue());
423 if (node->nodeType() == Node::ELEMENT_NODE) {
424 Node* child = node->firstChild();
426 OwnPtr<Digest> childInfo = createDigest(child, unusedNodesMap);
427 addStringToDigestor(digestor.get(), childInfo->m_sha1);
428 child = child->nextSibling();
429 digest->m_children.append(childInfo.release());
431 Element* element = toElement(node);
433 if (element->hasAttributesWithoutUpdate()) {
434 size_t numAttrs = element->attributeCount();
435 OwnPtr<blink::WebCryptoDigestor> attrsDigestor = createDigestor(HashAlgorithmSha1);
436 for (size_t i = 0; i < numAttrs; ++i) {
437 const Attribute& attribute = element->attributeItem(i);
438 addStringToDigestor(attrsDigestor.get(), attribute.name().toString());
439 addStringToDigestor(attrsDigestor.get(), attribute.value().string());
441 finishDigestor(attrsDigestor.get(), digestResult);
442 digest->m_attrsSHA1 = base64Encode(reinterpret_cast<const char*>(digestResult.data()), 10);
443 addStringToDigestor(digestor.get(), digest->m_attrsSHA1);
444 digestResult.clear();
447 finishDigestor(digestor.get(), digestResult);
448 digest->m_sha1 = base64Encode(reinterpret_cast<const char*>(digestResult.data()), 10);
451 unusedNodesMap->add(digest->m_sha1, digest);
452 return adoptPtr(digest);
455 bool DOMPatchSupport::insertBeforeAndMarkAsUsed(ContainerNode* parentNode, Digest* digest, Node* anchor, ExceptionState& exceptionState)
457 bool result = m_domEditor->insertBefore(parentNode, digest->m_node, anchor, exceptionState);
458 markNodeAsUsed(digest);
462 bool DOMPatchSupport::removeChildAndMoveToNew(Digest* oldDigest, ExceptionState& exceptionState)
464 RefPtr<Node> oldNode = oldDigest->m_node;
465 if (!m_domEditor->removeChild(oldNode->parentNode(), oldNode.get(), exceptionState))
468 // Diff works within levels. In order not to lose the node identity when user
469 // prepends his HTML with "<div>" (i.e. all nodes are shifted to the next nested level),
470 // prior to dropping the original node on the floor, check whether new DOM has a digest
471 // with matching sha1. If it does, replace it with the original DOM chunk. Chances are
472 // high that it will get merged back into the original DOM during the further patching.
473 UnusedNodesMap::iterator it = m_unusedNodesMap.find(oldDigest->m_sha1);
474 if (it != m_unusedNodesMap.end()) {
475 Digest* newDigest = it->value;
476 Node* newNode = newDigest->m_node;
477 if (!m_domEditor->replaceChild(newNode->parentNode(), oldNode, newNode, exceptionState))
479 newDigest->m_node = oldNode.get();
480 markNodeAsUsed(newDigest);
484 for (size_t i = 0; i < oldDigest->m_children.size(); ++i) {
485 if (!removeChildAndMoveToNew(oldDigest->m_children[i].get(), exceptionState))
491 void DOMPatchSupport::markNodeAsUsed(Digest* digest)
493 Deque<Digest*> queue;
494 queue.append(digest);
495 while (!queue.isEmpty()) {
496 Digest* first = queue.takeFirst();
497 m_unusedNodesMap.remove(first->m_sha1);
498 for (size_t i = 0; i < first->m_children.size(); ++i)
499 queue.append(first->m_children[i].get());
503 #ifdef DEBUG_DOM_PATCH_SUPPORT
504 static String nodeName(Node* node)
506 if (node->document().isXHTMLDocument())
507 return node->nodeName();
508 return node->nodeName().lower();
511 void DOMPatchSupport::dumpMap(const ResultMap& map, const String& name)
513 fprintf(stderr, "\n\n");
514 for (size_t i = 0; i < map.size(); ++i)
515 fprintf(stderr, "%s[%lu]: %s (%p) - [%lu]\n", name.utf8().data(), i, map[i].first ? nodeName(map[i].first->m_node).utf8().data() : "", map[i].first, map[i].second);
519 } // namespace WebCore