2 * Copyright (C) 2012 Google Inc. All rights reserved.
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions are
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
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.
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.
32 #include "core/inspector/DOMPatchSupport.h"
34 #include "bindings/core/v8/ExceptionState.h"
35 #include "bindings/core/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/NodeTraversal.h"
42 #include "core/dom/XMLDocument.h"
43 #include "core/html/HTMLBodyElement.h"
44 #include "core/html/HTMLDocument.h"
45 #include "core/html/HTMLHeadElement.h"
46 #include "core/html/parser/HTMLDocumentParser.h"
47 #include "core/inspector/DOMEditor.h"
48 #include "core/inspector/InspectorHistory.h"
49 #include "core/xml/parser/XMLDocumentParser.h"
50 #include "platform/Crypto.h"
51 #include "public/platform/Platform.h"
52 #include "wtf/Deque.h"
53 #include "wtf/HashTraits.h"
54 #include "wtf/RefPtr.h"
55 #include "wtf/text/Base64.h"
56 #include "wtf/text/CString.h"
60 struct DOMPatchSupport::Digest {
61 explicit Digest(Node* node) : m_node(node) { }
66 Vector<OwnPtr<Digest> > m_children;
69 void DOMPatchSupport::patchDocument(Document& document, const String& markup)
71 InspectorHistory history;
72 DOMEditor domEditor(&history);
73 DOMPatchSupport patchSupport(&domEditor, document);
74 patchSupport.patchDocument(markup);
77 DOMPatchSupport::DOMPatchSupport(DOMEditor* domEditor, Document& document)
78 : m_domEditor(domEditor)
79 , m_document(document)
83 void DOMPatchSupport::patchDocument(const String& markup)
85 RefPtrWillBeRawPtr<Document> newDocument = nullptr;
86 if (document().isHTMLDocument())
87 newDocument = HTMLDocument::create();
88 else if (document().isXHTMLDocument())
89 newDocument = XMLDocument::createXHTML();
90 else if (document().isXMLDocument())
91 newDocument = XMLDocument::create();
94 newDocument->setContextFeatures(document().contextFeatures());
95 RefPtrWillBeRawPtr<DocumentParser> parser = nullptr;
96 if (document().isHTMLDocument())
97 parser = HTMLDocumentParser::create(toHTMLDocument(*newDocument), false);
99 parser = XMLDocumentParser::create(*newDocument, 0);
100 parser->insert(markup); // Use insert() so that the parser will not yield.
104 OwnPtr<Digest> oldInfo = createDigest(document().documentElement(), 0);
105 OwnPtr<Digest> newInfo = createDigest(newDocument->documentElement(), &m_unusedNodesMap);
107 if (!innerPatchNode(oldInfo.get(), newInfo.get(), IGNORE_EXCEPTION)) {
108 // Fall back to rewrite.
109 document().write(markup);
114 Node* DOMPatchSupport::patchNode(Node* node, const String& markup, ExceptionState& exceptionState)
116 // Don't parse <html> as a fragment.
117 if (node->isDocumentNode() || (node->parentNode() && node->parentNode()->isDocumentNode())) {
118 patchDocument(markup);
122 Node* previousSibling = node->previousSibling();
123 RefPtrWillBeRawPtr<DocumentFragment> fragment = DocumentFragment::create(document());
124 Node* targetNode = node->parentElementOrShadowRoot() ? node->parentElementOrShadowRoot() : document().documentElement();
126 // Use the document BODY as the context element when editing immediate shadow root children,
127 // as it provides an equivalent parsing context.
128 if (targetNode->isShadowRoot())
129 targetNode = document().body();
130 Element* targetElement = toElement(targetNode);
132 // FIXME: This code should use one of createFragment* in markup.h
133 if (document().isHTMLDocument())
134 fragment->parseHTML(markup, targetElement);
136 fragment->parseXML(markup, targetElement);
138 // Compose the old list.
139 ContainerNode* parentNode = node->parentNode();
140 Vector<OwnPtr<Digest> > oldList;
141 for (Node* child = parentNode->firstChild(); child; child = child->nextSibling())
142 oldList.append(createDigest(child, 0));
144 // Compose the new list.
145 String markupCopy = markup.lower();
146 Vector<OwnPtr<Digest> > newList;
147 for (Node* child = parentNode->firstChild(); child != node; child = child->nextSibling())
148 newList.append(createDigest(child, 0));
149 for (Node* child = fragment->firstChild(); child; child = child->nextSibling()) {
150 if (isHTMLHeadElement(*child) && !child->hasChildren() && markupCopy.find("</head>") == kNotFound)
151 continue; // HTML5 parser inserts empty <head> tag whenever it parses <body>
152 if (isHTMLBodyElement(*child) && !child->hasChildren() && markupCopy.find("</body>") == kNotFound)
153 continue; // HTML5 parser inserts empty <body> tag whenever it parses </head>
154 newList.append(createDigest(child, &m_unusedNodesMap));
156 for (Node* child = node->nextSibling(); child; child = child->nextSibling())
157 newList.append(createDigest(child, 0));
159 if (!innerPatchChildren(parentNode, oldList, newList, exceptionState)) {
160 // Fall back to total replace.
161 if (!m_domEditor->replaceChild(parentNode, fragment.release(), node, exceptionState))
164 return previousSibling ? previousSibling->nextSibling() : parentNode->firstChild();
167 bool DOMPatchSupport::innerPatchNode(Digest* oldDigest, Digest* newDigest, ExceptionState& exceptionState)
169 if (oldDigest->m_sha1 == newDigest->m_sha1)
172 Node* oldNode = oldDigest->m_node;
173 Node* newNode = newDigest->m_node;
175 if (newNode->nodeType() != oldNode->nodeType() || newNode->nodeName() != oldNode->nodeName())
176 return m_domEditor->replaceChild(oldNode->parentNode(), newNode, oldNode, exceptionState);
178 if (oldNode->nodeValue() != newNode->nodeValue()) {
179 if (!m_domEditor->setNodeValue(oldNode, newNode->nodeValue(), exceptionState))
183 if (!oldNode->isElementNode())
187 Element* oldElement = toElement(oldNode);
188 Element* newElement = toElement(newNode);
189 if (oldDigest->m_attrsSHA1 != newDigest->m_attrsSHA1) {
190 // FIXME: Create a function in Element for removing all properties. Take in account whether did/willModifyAttribute are important.
191 while (oldElement->attributesWithoutUpdate().size()) {
192 const Attribute& attribute = oldElement->attributesWithoutUpdate().at(0);
193 if (!m_domEditor->removeAttribute(oldElement, attribute.localName(), exceptionState))
197 // FIXME: Create a function in Element for copying properties. cloneDataFromElement() is close but not enough for this case.
198 AttributeCollection attributes = newElement->attributesWithoutUpdate();
199 AttributeCollection::iterator end = attributes.end();
200 for (AttributeCollection::iterator it = attributes.begin(); it != end; ++it) {
201 if (!m_domEditor->setAttribute(oldElement, it->name().localName(), it->value(), exceptionState))
206 bool result = innerPatchChildren(oldElement, oldDigest->m_children, newDigest->m_children, exceptionState);
207 m_unusedNodesMap.remove(newDigest->m_sha1);
211 pair<DOMPatchSupport::ResultMap, DOMPatchSupport::ResultMap>
212 DOMPatchSupport::diff(const Vector<OwnPtr<Digest> >& oldList, const Vector<OwnPtr<Digest> >& newList)
214 ResultMap newMap(newList.size());
215 ResultMap oldMap(oldList.size());
217 for (size_t i = 0; i < oldMap.size(); ++i) {
219 oldMap[i].second = 0;
222 for (size_t i = 0; i < newMap.size(); ++i) {
224 newMap[i].second = 0;
227 // Trim head and tail.
228 for (size_t i = 0; i < oldList.size() && i < newList.size() && oldList[i]->m_sha1 == newList[i]->m_sha1; ++i) {
229 oldMap[i].first = oldList[i].get();
230 oldMap[i].second = i;
231 newMap[i].first = newList[i].get();
232 newMap[i].second = i;
234 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) {
235 size_t oldIndex = oldList.size() - i - 1;
236 size_t newIndex = newList.size() - i - 1;
237 oldMap[oldIndex].first = oldList[oldIndex].get();
238 oldMap[oldIndex].second = newIndex;
239 newMap[newIndex].first = newList[newIndex].get();
240 newMap[newIndex].second = oldIndex;
243 typedef HashMap<String, Vector<size_t> > DiffTable;
247 for (size_t i = 0; i < newList.size(); ++i) {
248 newTable.add(newList[i]->m_sha1, Vector<size_t>()).storedValue->value.append(i);
251 for (size_t i = 0; i < oldList.size(); ++i) {
252 oldTable.add(oldList[i]->m_sha1, Vector<size_t>()).storedValue->value.append(i);
255 for (DiffTable::iterator newIt = newTable.begin(); newIt != newTable.end(); ++newIt) {
256 if (newIt->value.size() != 1)
259 DiffTable::iterator oldIt = oldTable.find(newIt->key);
260 if (oldIt == oldTable.end() || oldIt->value.size() != 1)
263 newMap[newIt->value[0]] = std::make_pair(newList[newIt->value[0]].get(), oldIt->value[0]);
264 oldMap[oldIt->value[0]] = std::make_pair(oldList[oldIt->value[0]].get(), newIt->value[0]);
267 for (size_t i = 0; newList.size() > 0 && i < newList.size() - 1; ++i) {
268 if (!newMap[i].first || newMap[i + 1].first)
271 size_t j = newMap[i].second + 1;
272 if (j < oldMap.size() && !oldMap[j].first && newList[i + 1]->m_sha1 == oldList[j]->m_sha1) {
273 newMap[i + 1] = std::make_pair(newList[i + 1].get(), j);
274 oldMap[j] = std::make_pair(oldList[j].get(), i + 1);
278 for (size_t i = newList.size() - 1; newList.size() > 0 && i > 0; --i) {
279 if (!newMap[i].first || newMap[i - 1].first || newMap[i].second <= 0)
282 size_t j = newMap[i].second - 1;
283 if (!oldMap[j].first && newList[i - 1]->m_sha1 == oldList[j]->m_sha1) {
284 newMap[i - 1] = std::make_pair(newList[i - 1].get(), j);
285 oldMap[j] = std::make_pair(oldList[j].get(), i - 1);
289 #ifdef DEBUG_DOM_PATCH_SUPPORT
290 dumpMap(oldMap, "OLD");
291 dumpMap(newMap, "NEW");
294 return std::make_pair(oldMap, newMap);
297 bool DOMPatchSupport::innerPatchChildren(ContainerNode* parentNode, const Vector<OwnPtr<Digest> >& oldList, const Vector<OwnPtr<Digest> >& newList, ExceptionState& exceptionState)
299 pair<ResultMap, ResultMap> resultMaps = diff(oldList, newList);
300 ResultMap& oldMap = resultMaps.first;
301 ResultMap& newMap = resultMaps.second;
306 // 1. First strip everything except for the nodes that retain. Collect pending merges.
307 HashMap<Digest*, Digest*> merges;
308 HashSet<size_t, WTF::IntHash<size_t>, WTF::UnsignedWithZeroKeyHashTraits<size_t> > usedNewOrdinals;
309 for (size_t i = 0; i < oldList.size(); ++i) {
310 if (oldMap[i].first) {
311 if (usedNewOrdinals.add(oldMap[i].second).isNewEntry)
314 oldMap[i].second = 0;
317 // Always match <head> and <body> tags with each other - we can't remove them from the DOM
319 if (isHTMLHeadElement(*oldList[i]->m_node)) {
320 oldHead = oldList[i].get();
323 if (isHTMLBodyElement(*oldList[i]->m_node)) {
324 oldBody = oldList[i].get();
328 // Check if this change is between stable nodes. If it is, consider it as "modified".
329 if (!m_unusedNodesMap.contains(oldList[i]->m_sha1) && (!i || oldMap[i - 1].first) && (i == oldMap.size() - 1 || oldMap[i + 1].first)) {
330 size_t anchorCandidate = i ? oldMap[i - 1].second + 1 : 0;
331 size_t anchorAfter = (i == oldMap.size() - 1) ? anchorCandidate + 1 : oldMap[i + 1].second;
332 if (anchorAfter - anchorCandidate == 1 && anchorCandidate < newList.size())
333 merges.set(newList[anchorCandidate].get(), oldList[i].get());
335 if (!removeChildAndMoveToNew(oldList[i].get(), exceptionState))
339 if (!removeChildAndMoveToNew(oldList[i].get(), exceptionState))
344 // Mark retained nodes as used, do not reuse node more than once.
345 HashSet<size_t, WTF::IntHash<size_t>, WTF::UnsignedWithZeroKeyHashTraits<size_t> > usedOldOrdinals;
346 for (size_t i = 0; i < newList.size(); ++i) {
347 if (!newMap[i].first)
349 size_t oldOrdinal = newMap[i].second;
350 if (usedOldOrdinals.contains(oldOrdinal)) {
351 // Do not map node more than once
353 newMap[i].second = 0;
356 usedOldOrdinals.add(oldOrdinal);
357 markNodeAsUsed(newMap[i].first);
360 // Mark <head> and <body> nodes for merge.
361 if (oldHead || oldBody) {
362 for (size_t i = 0; i < newList.size(); ++i) {
363 if (oldHead && isHTMLHeadElement(*newList[i]->m_node))
364 merges.set(newList[i].get(), oldHead);
365 if (oldBody && isHTMLBodyElement(*newList[i]->m_node))
366 merges.set(newList[i].get(), oldBody);
370 // 2. Patch nodes marked for merge.
371 for (HashMap<Digest*, Digest*>::iterator it = merges.begin(); it != merges.end(); ++it) {
372 if (!innerPatchNode(it->value, it->key, exceptionState))
376 // 3. Insert missing nodes.
377 for (size_t i = 0; i < newMap.size(); ++i) {
378 if (newMap[i].first || merges.contains(newList[i].get()))
380 if (!insertBeforeAndMarkAsUsed(parentNode, newList[i].get(), NodeTraversal::childAt(*parentNode, i), exceptionState))
384 // 4. Then put all nodes that retained into their slots (sort by new index).
385 for (size_t i = 0; i < oldMap.size(); ++i) {
386 if (!oldMap[i].first)
388 RefPtrWillBeRawPtr<Node> node = oldMap[i].first->m_node;
389 Node* anchorNode = NodeTraversal::childAt(*parentNode, oldMap[i].second);
390 if (node == anchorNode)
392 if (isHTMLBodyElement(*node) || isHTMLHeadElement(*node))
393 continue; // Never move head or body, move the rest of the nodes around them.
395 if (!m_domEditor->insertBefore(parentNode, node.release(), anchorNode, exceptionState))
401 static void addStringToDigestor(blink::WebCryptoDigestor* digestor, const String& string)
403 digestor->consume(reinterpret_cast<const unsigned char*>(string.utf8().data()), string.length());
406 PassOwnPtr<DOMPatchSupport::Digest> DOMPatchSupport::createDigest(Node* node, UnusedNodesMap* unusedNodesMap)
408 Digest* digest = new Digest(node);
410 OwnPtr<blink::WebCryptoDigestor> digestor = createDigestor(HashAlgorithmSha1);
411 DigestValue digestResult;
413 Node::NodeType nodeType = node->nodeType();
414 digestor->consume(reinterpret_cast<const unsigned char*>(&nodeType), sizeof(nodeType));
415 addStringToDigestor(digestor.get(), node->nodeName());
416 addStringToDigestor(digestor.get(), node->nodeValue());
418 if (node->isElementNode()) {
419 Element& element = toElement(*node);
420 Node* child = element.firstChild();
422 OwnPtr<Digest> childInfo = createDigest(child, unusedNodesMap);
423 addStringToDigestor(digestor.get(), childInfo->m_sha1);
424 child = child->nextSibling();
425 digest->m_children.append(childInfo.release());
428 AttributeCollection attributes = element.attributesWithoutUpdate();
429 if (!attributes.isEmpty()) {
430 OwnPtr<blink::WebCryptoDigestor> attrsDigestor = createDigestor(HashAlgorithmSha1);
431 AttributeCollection::iterator end = attributes.end();
432 for (AttributeCollection::iterator it = attributes.begin(); it != end; ++it) {
433 addStringToDigestor(attrsDigestor.get(), it->name().toString());
434 addStringToDigestor(attrsDigestor.get(), it->value().string());
436 finishDigestor(attrsDigestor.get(), digestResult);
437 digest->m_attrsSHA1 = base64Encode(reinterpret_cast<const char*>(digestResult.data()), 10);
438 addStringToDigestor(digestor.get(), digest->m_attrsSHA1);
439 digestResult.clear();
442 finishDigestor(digestor.get(), digestResult);
443 digest->m_sha1 = base64Encode(reinterpret_cast<const char*>(digestResult.data()), 10);
446 unusedNodesMap->add(digest->m_sha1, digest);
447 return adoptPtr(digest);
450 bool DOMPatchSupport::insertBeforeAndMarkAsUsed(ContainerNode* parentNode, Digest* digest, Node* anchor, ExceptionState& exceptionState)
452 bool result = m_domEditor->insertBefore(parentNode, digest->m_node, anchor, exceptionState);
453 markNodeAsUsed(digest);
457 bool DOMPatchSupport::removeChildAndMoveToNew(Digest* oldDigest, ExceptionState& exceptionState)
459 RefPtrWillBeRawPtr<Node> oldNode = oldDigest->m_node;
460 if (!m_domEditor->removeChild(oldNode->parentNode(), oldNode.get(), exceptionState))
463 // Diff works within levels. In order not to lose the node identity when user
464 // prepends his HTML with "<div>" (i.e. all nodes are shifted to the next nested level),
465 // prior to dropping the original node on the floor, check whether new DOM has a digest
466 // with matching sha1. If it does, replace it with the original DOM chunk. Chances are
467 // high that it will get merged back into the original DOM during the further patching.
468 UnusedNodesMap::iterator it = m_unusedNodesMap.find(oldDigest->m_sha1);
469 if (it != m_unusedNodesMap.end()) {
470 Digest* newDigest = it->value;
471 Node* newNode = newDigest->m_node;
472 if (!m_domEditor->replaceChild(newNode->parentNode(), oldNode, newNode, exceptionState))
474 newDigest->m_node = oldNode.get();
475 markNodeAsUsed(newDigest);
479 for (size_t i = 0; i < oldDigest->m_children.size(); ++i) {
480 if (!removeChildAndMoveToNew(oldDigest->m_children[i].get(), exceptionState))
486 void DOMPatchSupport::markNodeAsUsed(Digest* digest)
488 Deque<Digest*> queue;
489 queue.append(digest);
490 while (!queue.isEmpty()) {
491 Digest* first = queue.takeFirst();
492 m_unusedNodesMap.remove(first->m_sha1);
493 for (size_t i = 0; i < first->m_children.size(); ++i)
494 queue.append(first->m_children[i].get());
498 #ifdef DEBUG_DOM_PATCH_SUPPORT
499 static String nodeName(Node* node)
501 if (node->document().isXHTMLDocument())
502 return node->nodeName();
503 return node->nodeName().lower();
506 void DOMPatchSupport::dumpMap(const ResultMap& map, const String& name)
508 fprintf(stderr, "\n\n");
509 for (size_t i = 0; i < map.size(); ++i)
510 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);