一、讀取url
面加載.jpg)
以下內(nèi)容部分引自
http://blog.csdn.net/dlmu2001/article/details/5936122http的協(xié)議細(xì)節(jié)實(shí)現(xiàn)并不需要WebCore來(lái)關(guān)注,WebCore要關(guān)注的是,如何設(shè)置請(qǐng)求的相關(guān)頭部信息,如何獲取服務(wù)器返回回來(lái)的響應(yīng)體部數(shù)據(jù)。
WebKit中同http打交道的類主要是ResourceRequest,ResourceResonse,ResourceHandle*,ResourceHandleManager等,這里先介紹同請(qǐng)求信息維護(hù)相關(guān)的ResourceRequest.
ResourceRequest類的作用比較好理解,基本上就是維護(hù)http請(qǐng)求相關(guān)的信息(app或者內(nèi)核都有可能設(shè)置這些信息),然后當(dāng)WebCore發(fā)起http請(qǐng)求的時(shí)候,可以獲取這些信息,調(diào)用curl的接口設(shè)置對(duì)應(yīng)的http請(qǐng)求字段。在這些信息中,最常用到的是url。
ResourceRequest類繼承于ResourceRequestBase類,絕大部分功能在ResourceRequestBase類中實(shí)現(xiàn)。
一)ResourceRequest構(gòu)造:構(gòu)造一個(gè)ResourceRequest對(duì)象只需要url參數(shù)就夠了,這是比較簡(jiǎn)單的一個(gè)類,沒(méi)有維護(hù)其它類的對(duì)象或者句柄。
ResourceRequest(const String& url);
ResourceRequest(const KURL& url);
二)ResourceRequest對(duì)象的創(chuàng)建與維護(hù)
1.當(dāng)用戶輸入網(wǎng)址,觸發(fā)qt事件,由
MainWindow(WebKitBuild/Debug/QtTestBrowser/moc_mainwindow.cpp:87<--moc_launcherwindow.cpp:145)調(diào)用
changeLocation函數(shù)(另有
openLocation等)。
由
MainWindow(Tools/QtTestBrowser/mainwindow.cpp:194)獲取地址欄中的url(
QString類型/usr/include/QtCore/qstring.h),創(chuàng)建QUrl類型(
/usr/include/QtCore/qurl.h url規(guī)格化類,包括host、port、scheme等成員變量),加載頁(yè)面(
page()->mainFrame()->load(url) page()函數(shù)是全局函數(shù)?)。
最終調(diào)用
QWebFrame::load(Source/WebKit/qt/Api/qwebframe.cpp:885)函數(shù),在該函數(shù)中,會(huì)構(gòu)造出ResourceRequest(
Source/WebCore/platform/network/qt/ResourceRequest.h繼承ResourceRequestBase
Source/WebCore/platform/network/ResourceRequestBase.cpp)對(duì)象,并將這個(gè)對(duì)象作為一個(gè)參數(shù),調(diào)用
FrameLoader對(duì)象的load函數(shù)(Source/WebCore/loader/FrameLoader.cpp:1450)。
FrameLoader類負(fù)責(zé)將documents加載到Frames。當(dāng)你點(diǎn)擊一個(gè)鏈接的時(shí)候,F(xiàn)rameLoader創(chuàng)建一個(gè)新的處于”policy”狀態(tài)的DocumentLoader對(duì)象,等待WebKit客戶端決定是否處理這個(gè)加載。通常WebKit客戶端會(huì)指示FrameLoader將這個(gè)加載視為一個(gè)導(dǎo)航(navigation),而不是阻止加載等。
DocumentLoader類中會(huì)維護(hù)這個(gè)ResourceRequest(
FrameLoader.cpp:1460),
policyChecker()
——>checkNavigationPolicy(Source/WebCore/loader/FrameLoader.cpp:1585)
1585 policyChecker()->checkNavigationPolicy(loader->request(), loader, formState,
1586 callContinueLoadAfterNavigationPolicy, this);//回調(diào)函數(shù)?如下調(diào)用
——>m_frame->loader()->client()->dispatchDecidePolicyForNavigationAction(Source/WebCore/loader/PolicyChecker.cpp:87)
84 m_callback.set(request, formState.get(), function, argument);//callContinueLoadAfterNavigationPolicy
一旦客戶端指示FrameLoader將本次加載視為一個(gè)導(dǎo)航,F(xiàn)rameLoader就推動(dòng)DocumentLoader進(jìn)入”provisional”狀態(tài),在該狀態(tài),DocumentLoader會(huì)發(fā)起一個(gè)網(wǎng)絡(luò)請(qǐng)求,并等待以確定網(wǎng)絡(luò)請(qǐng)求將發(fā)起一個(gè)下載還是一個(gè)新的document。
——>page->d->acceptNavigationRequest(Source/WebKit/qt/WebCoreSupport/FrameLoaderClientQt.cpp:1271)
callPolicyFunction(Source/WebKit/qt/WebCoreSupport/FrameLoaderClientQt.cpp:1283)
回調(diào)函數(shù)?如上
//——>(m_frame->loader()->policyChecker()->*function)(action) (245)
——>callback.call(Source/WebCore/loader/PolicyChecker.cpp:160)
——>m_navigationFunction(Source/WebCore/loader/PolicyCallback.cpp:103)
——>loader->continueLoadAfterNavigationPolicy(Source/WebCore/loader/FrameLoader.cpp:2977)
2974 void FrameLoader::callContinueLoadAfterNavigationPolicy(void* argument,
2975 const ResourceRequest& request, PassRefPtr<FormState> formState, bool shouldContinue)

2976
{
2977 FrameLoader* loader = static_cast<FrameLoader*>(argument);
2978 loader->continueLoadAfterNavigationPolicy(request, formState, shouldContinue);
2979 }
——>continueLoadAfterWillSubmitForm(Source/WebCore/loader/FrameLoader.cpp:3105)
——>m_provisionalDocumentLoader->startLoadingMainResource(Source/WebCore/loader/FrameLoader.cpp:2572)
接下去,DocumentLoader會(huì)創(chuàng)建一個(gè)MainResourceLoader對(duì)象,這個(gè)對(duì)象主要用來(lái)通過(guò)ResourceHandle接口同平臺(tái)網(wǎng)絡(luò)庫(kù)進(jìn)行交互。將MainResourceLoader和DocumentLoader分開(kāi)來(lái)主要有兩個(gè)目的:(1)MainResourceLoader讓DocumentLoader從處理ResourceHandle回調(diào)的細(xì)節(jié)中抽身出來(lái)(2)降低MainResourceLoader的生命周期和DocumentLoader的生命周期(同Document綁定)的耦合度。
——>m_mainResourceLoader->load(Source/WebCore/loader/DocumentLoader.cpp:798)
——>loadNow(Source/WebCore/loader/MainResourceLoader.cpp:612)
——>ResourceHandle::create(Source/WebCore/loader/MainResourceLoader.cpp:585)
——>newHandle->start(Source/WebCore/platform/network/ResourceHandle.cpp:71)
——>new QNetworkReplyHandler(Source/WebCore/platform/network/qt/ResourceHandleQt.cpp:100)
——>r.toNetworkRequest(Source/WebCore/platform/network/qt/QNetworkReplyHandler.cpp:399) 設(shè)置http頭
——>m_queue.push 提交事件? (Source/WebCore/platform/network/qt/QNetworkReplyHandler.cpp:401)
——>flush();(Source/WebCore/platform/network/qt/QNetworkReplyHandler.cpp:164)
——>(m_replyHandler->*(m_enqueuedCalls.takeFirst()))(); (Source/WebCore/platform/network/qt/QNetworkReplyHandler.cpp:195)
——>QNetworkReplyHandler::start() (Source/WebCore/platform/network/qt/QNetworkReplyHandler.cpp:659)
建立連接(ESTABLISHED)、發(fā)送請(qǐng)求 665: QNetworkReply* reply = sendNetworkRequest(d->m_context->networkAccessManager(), d->m_firstRequest);
——>601 WebCore::QNetworkReplyHandler::sendNetworkRequest
——>626 manager->get(m_request)
665 QNetworkReply* reply = sendNetworkRequest(d->m_context->networkAccessManager(), d->m_firstRequest);
669 m_replyWrapper = new QNetworkReplyWrapper(&m_queue, reply, m_resourceHandle->shouldContentSniff() && d->m_context-
>mimeSniffingEnabled(), this);
——>208 QNetworkReplyWrapper::QNetworkReplyWrapper(QNetworkReplyHandlerCallQueue* queue, QNetworkReply* reply, bool
sniffMIMETypes, QObject* parent)
209 : QObject(parent)
210 , m_reply(reply)
211 , m_queue(queue)
212 , m_responseContainsData(false)
213 , m_sniffMIMETypes(sniffMIMETypes)
214 {
215 Q_ASSERT(m_reply);
216
217 // setFinished() must be the first that we connect, so isFinished() is updated when running other slots.
//QT通過(guò)此種方式異步回調(diào)??(yes, 信號(hào)、槽機(jī)制,http://www.ibm.com/developerworks/cn/linux/guitoolkit/qt/signal-slot/ )
218 connect(m_reply, SIGNAL(finished()), this, SLOT(setFinished()));
219 connect(m_reply, SIGNAL(finished()), this, SLOT(receiveMetaData()));
220 connect(m_reply, SIGNAL(readyRead()), this, SLOT(receiveMetaData()));
221 }
一旦加載系統(tǒng)接收到足夠的信息可以確定資源確實(shí)代表了document,F(xiàn)rameLoader就將DocumentLoader推向”committed”狀態(tài),在該狀態(tài)中,frame將顯示document。
下載完了之后
——>QtMIMETypeSniffer::qt_metacall() (WebKitBuild/Debug/WebCore/moc_QtMIMETypeSniffer.cpp:77)
——>trySniffing()(Source/WebCore/platform/network/qt/QtMIMETypeSniffer.cpp:59)
——>m_sniffer.sniff(data.constData(), data.size())(Source/WebCore/platform/network/qt/QtMIMETypeSniffer.cpp:51)
50 QByteArray data = m_reply->peek(m_sniffer.dataSize());
51 const char* sniffedMimeType = m_sniffer.sniff(data.constData(), data.size()); data.constData()保存著網(wǎng)頁(yè)內(nèi)容,涉及的變量包括m_reply、m_sniffer
——>emit finished (Source/WebCore/platform/network/qt/QtMIMETypeSniffer.cpp:65)
——>QMetaObject::activate(WebKitBuild/Debug/WebCore/moc_QtMIMETypeSniffer.cpp:88)
……
WebCore::QNetworkReplyWrapper::qt_metacall (WebKitBuild/Debug/WebCore/moc_QNetworkReplyHandler.cpp)

77 if (_c == QMetaObject::InvokeMetaMethod)
{

78 switch (_id)
{
79 case 0: receiveMetaData(); break;
80 case 1: didReceiveFinished(); break;
81 case 2: didReceiveReadyRead(); break;
82 case 3: receiveSniffedMIMEType(); break;
83 case 4: setFinished(); break;
84 default: ;
85 }
86 _id -= 5;
87 }
——>receiveSniffedMIMEType()(WebKitBuild/Debug/WebCore/moc_QNetworkReplyHandler.cpp:82)
——>emitMetaDataChanged()(Source/WebCore/platform/network/qt/QNetworkReplyHandler.cpp:305)
——>QueueLocker lock(m_queue)(Source/WebCore/platform/network/qt/QNetworkReplyHandler.cpp)
——>~QueueLocker() { m_queue->unlock(); } (203)
——>flush();(178)
——>(m_replyHandler->*(m_enqueuedCalls.takeFirst()))(); (195)
——>1、QNetworkReplyHandler::forwardData (572)
——>client->didReceiveData(m_resourceHandle, data.constData(), data.length(), -1); (586)
——>ResourceLoader::didReceiveData(ResourceHandle*, const char* data, int length, int encodedDataLength) (Source/WebCore/loader/ResourceLoader.cpp:427)
data指向保存頁(yè)面內(nèi)容
——>MainResourceLoader::didReceiveData (Source/WebCore/loader/MainResourceLoader.cpp:431)
——>ResourceLoader::didReceiveData (Source/WebCore/loader/ResourceLoader.cpp:267)
279 addData(data, length, allAtOnce);
280 // FIXME: If we get a resource with more than 2B bytes, this code won't do the right thing.
281 // However, with today's computers and networking speeds, this won't happen in practice.
282 // Could be an issue with a giant local file.
283 if (m_sendResourceLoadCallbacks && m_frame)
284 frameLoader()->notifier()->didReceiveData(this, data, length, static_cast<int>(encodedDataLength)); 保存頁(yè)面到cache 函數(shù): addData()
——>ResourceLoadNotifier::didReceiveData (Source/WebCore/loader/ResourceLoadNotifier.cpp:77)
——>ResourceLoadNotifier::dispatchDidReceiveContentLength (133)
——>InspectorInstrumentation::didReceiveContentLength (Source/WebCore/inspector/InspectorInstrumentation.h:713)
——>InspectorInstrumentation::didReceiveContentLengthImpl (Source/WebCore/inspector/InspectorInstrumentation.cpp:487)
html解析
——>2、QNetworkReplyHandler::finish(Source/WebCore/platform/network/qt/QNetworkReplyHandler.cpp:437)
——>ResourceLoader::didFinishLoading (Source/WebCore/loader/ResourceLoader.cpp:434)
——>MainResourceLoader::didFinishLoading (Source/WebCore/loader/MainResourceLoader.cpp:466)
——>FrameLoader::finishedLoading (Source/WebCore/loader/FrameLoader.cpp:2287)
——>DocumentLoader::finishedLoading (Source/WebCore/loader/DocumentLoader.cpp:282)
——>FrameLoader::finishedLoadingDocument(DocumentLoader* loader) (Source/WebCore/loader/FrameLoader.cpp:2333)
——>FrameLoaderClientQt::finishedLoading(DocumentLoader* loader) (Source/WebKit/qt/WebCoreSupport/FrameLoaderClientQt.cpp:626)
——>DocumentWriter::end() (Source/WebCore/loader/DocumentWriter.cpp:211)
211 void DocumentWriter::end()

212
{
213 m_frame->loader()->didEndDocument();
214 endIfNotLoadingMainResource();
215 } 213 ——>Document::finishParsing() (Source/WebCore/dom/Document.cpp:2246)
214: DocumentWriter::endIfNotLoadingMainResource() (Source/WebCore/loader/DocumentWriter.cpp 228)
228 addData(0, 0, true);
229 m_frame->document()->finishParsing(); ——>DocumentWriter::addData() (208)
——>DecodedDataDocumentParser::appendBytes(DocumentWriter* writer , const char* data, int length, bool shouldFlush) (Source/WebCore/dom/DecodedDataDocumentParser.cpp:40)
——> HTMLDocumentParser::append(const SegmentedString& source) (Source/WebCore/html/parser/HTMLDocumentParser.cpp:367)
——> HTMLDocumentParser::pumpTokenizerIfPossible(SynchronousMode mode) (175)
——> HTMLDocumentParser::pumpTokenizer(SynchronousMode mode) (261)
解析、執(zhí)行script
——> HTMLDocumentParser::canTakeNextToken(SynchronousMode mode, PumpSession& session) (223)
——> HTMLDocumentParser::runScriptsForPausedTreeBuilder() (205)
——> HTMLScriptRunner::execute(PassRefPtr<Element> scriptElement, const TextPosition1& scriptStartPosition) Source/WebCore/html/parser/HTMLScriptRunner.cpp:167)
——> WebCore::HTMLScriptRunner::runScript(this=0x81e2a58, script=0x832c040, scriptStartPosition=...) (296)
——> WebCore::ScriptElement::prepareScript (this=0x832c084, scriptStartPosition=..., supportLegacyTypes=WebCore::ScriptElement::DisallowLegacyTypeInTypeAttribute) (Source/WebCore/dom/ScriptElement.cpp:240)
——> WebCore::ScriptElement::executeScript (this=0x832c084, sourceCode=...) (283)
——> WebCore::ScriptController::evaluate (this=0x828d1a4, sourceCode=...) (Source/WebCore/bindings/js/ScriptController.cpp:166)
——> WebCore::ScriptController::evaluateInWorld (143)
——> WebCore::JSMainThreadExecState::evaluate (Source/WebCore/bindings/js/JSMainThreadExecState.h:54)
——> JSC::evaluate(exec=0xae3f499c, scopeChain=0xae3ee5c8, source=..., thisValue=...) (Source/JavaScriptCore/runtime/Completion.cpp:64)
——> JSC::Interpreter::execute (Source/JavaScriptCore/interpreter/Interpreter.cpp:767)
——> JSC::JITCode::execute (Source/JavaScriptCore/jit/JITCode.h:77)
——> ?? ()
——> WebCore::jsHTMLDocumentPrototypeFunctionWrite(WebCore/generated/JSHTMLDocument.cpp:445)
——> WebCore::JSHTMLDocument::write (Source/WebCore/bindings/js/JSHTMLDocumentCustom.cpp:161)
——> WebCore::documentWrite (156)
——> WebCore::Document::write (Source/WebCore/dom/Document.cpp:2227)
——> WebCore::HTMLDocumentParser::insert (Source/WebCore/html/parser/HTMLDocumentParser.cpp:324)
回到了html的解析
——> WebCore::HTMLDocumentParser::pumpTokenizerIfPossible (175)
——> WebCore::HTMLDocumentParser::pumpTokenizer (299)
查看是否有script,1、如果有,轉(zhuǎn)到“ 解析、執(zhí)行script”;2、如果沒(méi)有轉(zhuǎn)到下面“”
完成解析html
InspectorInstrumentation::didWriteHTML(cookie, m_tokenizer->lineNumber());
——> InspectorInstrumentation::didWriteHTML (Source/WebCore/inspector/InspectorInstrumentation.h:803)
——>
——> Document::finishParsing() (Source/WebCore/dom/Document.cpp:2259)
——>HTMLDocumentParser::finish() (Source/WebCore/html/parser/HTMLDocumentParser.cpp:427)
——>HTMLDocumentParser::attemptToEnd() (399)
——>
生成dom樹(shù)
附件(js)下載、解析
二、下載
三、加載
參考文檔
1.官方文檔:http://www.webkit.org/blog/1188/how-webkit-loads-a-web-page/
2.dlmu2001的譯文:http://blog.csdn.net/dlmu2001/article/details/5941432
3.dlmu200:WebCore中的http請(qǐng)求信息維護(hù) http://blog.csdn.net/dlmu2001/article/details/59361221
4.其他技術(shù)性文章:Introduction to WebKit Objective-C Programming Guide http://developer.apple.com/library/mac/#documentation/Cocoa/Conceptual/DisplayWebContent/DisplayWebContent.html
5.其他技術(shù)性文章:Introduction to WebKit DOM Programming Topics http://developer.apple.com/library/mac/#documentation/AppleApplications/Conceptual/SafariJSProgTopics/WebKitJavaScript.html
6. http://www.webkit.org/coding/technical-articles.html
相關(guān)技巧
1.cscope查找類的定義:cs find e class.*QString[^;]*($|{)