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/*
* Copyright (C) 2010 Google, Inc. All Rights Reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
* OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "config.h"
#include "core/html/parser/HTMLDocumentParser.h"
#include "HTMLNames.h"
#include "core/dom/DocumentFragment.h"
#include "core/dom/Element.h"
#include "core/html/HTMLDocument.h"
#include "core/html/parser/AtomicHTMLToken.h"
#include "core/html/parser/BackgroundHTMLParser.h"
#include "core/html/parser/CompactHTMLToken.h"
#include "core/html/parser/HTMLIdentifier.h"
#include "core/html/parser/HTMLParserScheduler.h"
#include "core/html/parser/HTMLParserThread.h"
#include "core/html/parser/HTMLPreloadScanner.h"
#include "core/html/parser/HTMLScriptRunner.h"
#include "core/html/parser/HTMLTokenizer.h"
#include "core/html/parser/HTMLTreeBuilder.h"
#include "core/inspector/InspectorInstrumentation.h"
#include "core/frame/Frame.h"
#include "platform/TraceEvent.h"
#include "wtf/Functional.h"
namespace WebCore {
using namespace HTMLNames;
// This is a direct transcription of step 4 from:
// http://www.whatwg.org/specs/web-apps/current-work/multipage/the-end.html#fragment-case
static HTMLTokenizer::State tokenizerStateForContextElement(Element* contextElement, bool reportErrors, const HTMLParserOptions& options)
{
if (!contextElement)
return HTMLTokenizer::DataState;
const QualifiedName& contextTag = contextElement->tagQName();
if (contextTag.matches(titleTag) || contextTag.matches(textareaTag))
return HTMLTokenizer::RCDATAState;
if (contextTag.matches(styleTag)
|| contextTag.matches(xmpTag)
|| contextTag.matches(iframeTag)
|| (contextTag.matches(noembedTag) && options.pluginsEnabled)
|| (contextTag.matches(noscriptTag) && options.scriptEnabled)
|| contextTag.matches(noframesTag))
return reportErrors ? HTMLTokenizer::RAWTEXTState : HTMLTokenizer::PLAINTEXTState;
if (contextTag.matches(scriptTag))
return reportErrors ? HTMLTokenizer::ScriptDataState : HTMLTokenizer::PLAINTEXTState;
if (contextTag.matches(plaintextTag))
return HTMLTokenizer::PLAINTEXTState;
return HTMLTokenizer::DataState;
}
HTMLDocumentParser::HTMLDocumentParser(HTMLDocument* document, bool reportErrors)
: ScriptableDocumentParser(document)
, m_options(document)
, m_token(m_options.useThreading ? nullptr : adoptPtr(new HTMLToken))
, m_tokenizer(m_options.useThreading ? nullptr : HTMLTokenizer::create(m_options))
, m_scriptRunner(HTMLScriptRunner::create(document, this))
, m_treeBuilder(HTMLTreeBuilder::create(this, document, parserContentPolicy(), reportErrors, m_options))
, m_parserScheduler(HTMLParserScheduler::create(this))
, m_xssAuditorDelegate(document)
, m_weakFactory(this)
, m_preloader(adoptPtr(new HTMLResourcePreloader(document)))
, m_isPinnedToMainThread(false)
, m_endWasDelayed(false)
, m_haveBackgroundParser(false)
, m_pumpSessionNestingLevel(0)
{
ASSERT(shouldUseThreading() || (m_token && m_tokenizer));
}
// FIXME: Member variables should be grouped into self-initializing structs to
// minimize code duplication between these constructors.
HTMLDocumentParser::HTMLDocumentParser(DocumentFragment* fragment, Element* contextElement, ParserContentPolicy parserContentPolicy)
: ScriptableDocumentParser(&fragment->document(), parserContentPolicy)
, m_options(&fragment->document())
, m_token(adoptPtr(new HTMLToken))
, m_tokenizer(HTMLTokenizer::create(m_options))
, m_treeBuilder(HTMLTreeBuilder::create(this, fragment, contextElement, this->parserContentPolicy(), m_options))
, m_xssAuditorDelegate(&fragment->document())
, m_weakFactory(this)
, m_isPinnedToMainThread(true)
, m_endWasDelayed(false)
, m_haveBackgroundParser(false)
, m_pumpSessionNestingLevel(0)
{
ASSERT(!shouldUseThreading());
bool reportErrors = false; // For now document fragment parsing never reports errors.
m_tokenizer->setState(tokenizerStateForContextElement(contextElement, reportErrors, m_options));
m_xssAuditor.initForFragment();
}
HTMLDocumentParser::~HTMLDocumentParser()
{
ASSERT(!m_parserScheduler);
ASSERT(!m_pumpSessionNestingLevel);
ASSERT(!m_preloadScanner);
ASSERT(!m_insertionPreloadScanner);
ASSERT(!m_haveBackgroundParser);
// FIXME: We should be able to ASSERT(m_speculations.isEmpty()),
// but there are cases where that's not true currently. For example,
// we we're told to stop parsing before we've consumed all the input.
}
void HTMLDocumentParser::pinToMainThread()
{
ASSERT(!m_haveBackgroundParser);
ASSERT(!m_isPinnedToMainThread);
m_isPinnedToMainThread = true;
if (!m_tokenizer) {
ASSERT(!m_token);
m_token = adoptPtr(new HTMLToken);
m_tokenizer = HTMLTokenizer::create(m_options);
}
}
void HTMLDocumentParser::detach()
{
if (m_haveBackgroundParser)
stopBackgroundParser();
DocumentParser::detach();
if (m_scriptRunner)
m_scriptRunner->detach();
m_treeBuilder->detach();
// FIXME: It seems wrong that we would have a preload scanner here.
// Yet during fast/dom/HTMLScriptElement/script-load-events.html we do.
m_preloadScanner.clear();
m_insertionPreloadScanner.clear();
m_parserScheduler.clear(); // Deleting the scheduler will clear any timers.
}
void HTMLDocumentParser::stopParsing()
{
DocumentParser::stopParsing();
m_parserScheduler.clear(); // Deleting the scheduler will clear any timers.
if (m_haveBackgroundParser)
stopBackgroundParser();
}
// This kicks off "Once the user agent stops parsing" as described by:
// http://www.whatwg.org/specs/web-apps/current-work/multipage/the-end.html#the-end
void HTMLDocumentParser::prepareToStopParsing()
{
// FIXME: It may not be correct to disable this for the background parser.
// That means hasInsertionPoint() may not be correct in some cases.
ASSERT(!hasInsertionPoint() || m_haveBackgroundParser);
// pumpTokenizer can cause this parser to be detached from the Document,
// but we need to ensure it isn't deleted yet.
RefPtr<HTMLDocumentParser> protect(this);
// NOTE: This pump should only ever emit buffered character tokens,
// so ForceSynchronous vs. AllowYield should be meaningless.
if (m_tokenizer) {
ASSERT(!m_haveBackgroundParser);
pumpTokenizerIfPossible(ForceSynchronous);
}
if (isStopped())
return;
DocumentParser::prepareToStopParsing();
// We will not have a scriptRunner when parsing a DocumentFragment.
if (m_scriptRunner)
document()->setReadyState(Document::Interactive);
// Setting the ready state above can fire mutation event and detach us
// from underneath. In that case, just bail out.
if (isDetached())
return;
attemptToRunDeferredScriptsAndEnd();
}
bool HTMLDocumentParser::isParsingFragment() const
{
return m_treeBuilder->isParsingFragment();
}
bool HTMLDocumentParser::processingData() const
{
return isScheduledForResume() || inPumpSession() || m_haveBackgroundParser;
}
void HTMLDocumentParser::pumpTokenizerIfPossible(SynchronousMode mode)
{
if (isStopped())
return;
if (isWaitingForScripts())
return;
// Once a resume is scheduled, HTMLParserScheduler controls when we next pump.
if (isScheduledForResume()) {
ASSERT(mode == AllowYield);
return;
}
pumpTokenizer(mode);
}
bool HTMLDocumentParser::isScheduledForResume() const
{
return m_parserScheduler && m_parserScheduler->isScheduledForResume();
}
// Used by HTMLParserScheduler
void HTMLDocumentParser::resumeParsingAfterYield()
{
ASSERT(!m_isPinnedToMainThread);
// pumpTokenizer can cause this parser to be detached from the Document,
// but we need to ensure it isn't deleted yet.
RefPtr<HTMLDocumentParser> protect(this);
if (m_haveBackgroundParser) {
pumpPendingSpeculations();
return;
}
// We should never be here unless we can pump immediately. Call pumpTokenizer()
// directly so that ASSERTS will fire if we're wrong.
pumpTokenizer(AllowYield);
endIfDelayed();
}
void HTMLDocumentParser::runScriptsForPausedTreeBuilder()
{
ASSERT(scriptingContentIsAllowed(parserContentPolicy()));
TextPosition scriptStartPosition = TextPosition::belowRangePosition();
RefPtr<Element> scriptElement = m_treeBuilder->takeScriptToProcess(scriptStartPosition);
// We will not have a scriptRunner when parsing a DocumentFragment.
if (m_scriptRunner)
m_scriptRunner->execute(scriptElement.release(), scriptStartPosition);
}
bool HTMLDocumentParser::canTakeNextToken(SynchronousMode mode, PumpSession& session)
{
if (isStopped())
return false;
ASSERT(!m_haveBackgroundParser || mode == ForceSynchronous);
if (isWaitingForScripts()) {
if (mode == AllowYield)
m_parserScheduler->checkForYieldBeforeScript(session);
// If we don't run the script, we cannot allow the next token to be taken.
if (session.needsYield)
return false;
// If we're paused waiting for a script, we try to execute scripts before continuing.
runScriptsForPausedTreeBuilder();
if (isStopped())
return false;
if (isWaitingForScripts())
return false;
}
// FIXME: It's wrong for the HTMLDocumentParser to reach back to the
// Frame, but this approach is how the old parser handled
// stopping when the page assigns window.location. What really
// should happen is that assigning window.location causes the
// parser to stop parsing cleanly. The problem is we're not
// perpared to do that at every point where we run JavaScript.
if (!isParsingFragment()
&& document()->frame() && document()->frame()->navigationScheduler().locationChangePending())
return false;
if (mode == AllowYield)
m_parserScheduler->checkForYieldBeforeToken(session);
return true;
}
void HTMLDocumentParser::didReceiveParsedChunkFromBackgroundParser(PassOwnPtr<ParsedChunk> chunk)
{
TRACE_EVENT0("webkit", "HTMLDocumentParser::didReceiveParsedChunkFromBackgroundParser");
// alert(), runModalDialog, and the JavaScript Debugger all run nested event loops
// which can cause this method to be re-entered. We detect re-entry using
// hasActiveParser(), save the chunk as a speculation, and return.
if (isWaitingForScripts() || !m_speculations.isEmpty() || document()->activeParserCount() > 0) {
m_preloader->takeAndPreload(chunk->preloads);
m_speculations.append(chunk);
return;
}
// processParsedChunkFromBackgroundParser can cause this parser to be detached from the Document,
// but we need to ensure it isn't deleted yet.
RefPtr<HTMLDocumentParser> protect(this);
ASSERT(m_speculations.isEmpty());
chunk->preloads.clear(); // We don't need to preload because we're going to parse immediately.
m_speculations.append(chunk);
pumpPendingSpeculations();
}
void HTMLDocumentParser::validateSpeculations(PassOwnPtr<ParsedChunk> chunk)
{
ASSERT(chunk);
if (isWaitingForScripts()) {
// We're waiting on a network script, just save the chunk, we'll get
// a second validateSpeculations call after the script completes.
// This call should have been made immediately after runScriptsForPausedTreeBuilder
// which may have started a network load and left us waiting.
ASSERT(!m_lastChunkBeforeScript);
m_lastChunkBeforeScript = chunk;
return;
}
ASSERT(!m_lastChunkBeforeScript);
OwnPtr<HTMLTokenizer> tokenizer = m_tokenizer.release();
OwnPtr<HTMLToken> token = m_token.release();
if (!tokenizer) {
// There must not have been any changes to the HTMLTokenizer state on
// the main thread, which means the speculation buffer is correct.
return;
}
// Currently we're only smart enough to reuse the speculation buffer if the tokenizer
// both starts and ends in the DataState. That state is simplest because the HTMLToken
// is always in the Uninitialized state. We should consider whether we can reuse the
// speculation buffer in other states, but we'd likely need to do something more
// sophisticated with the HTMLToken.
if (chunk->tokenizerState == HTMLTokenizer::DataState
&& tokenizer->state() == HTMLTokenizer::DataState
&& m_input.current().isEmpty()
&& chunk->treeBuilderState == HTMLTreeBuilderSimulator::stateFor(m_treeBuilder.get())) {
ASSERT(token->isUninitialized());
return;
}
discardSpeculationsAndResumeFrom(chunk, token.release(), tokenizer.release());
}
void HTMLDocumentParser::discardSpeculationsAndResumeFrom(PassOwnPtr<ParsedChunk> lastChunkBeforeScript, PassOwnPtr<HTMLToken> token, PassOwnPtr<HTMLTokenizer> tokenizer)
{
m_weakFactory.revokeAll();
m_speculations.clear();
OwnPtr<BackgroundHTMLParser::Checkpoint> checkpoint = adoptPtr(new BackgroundHTMLParser::Checkpoint);
checkpoint->parser = m_weakFactory.createWeakPtr();
checkpoint->token = token;
checkpoint->tokenizer = tokenizer;
checkpoint->treeBuilderState = HTMLTreeBuilderSimulator::stateFor(m_treeBuilder.get());
checkpoint->inputCheckpoint = lastChunkBeforeScript->inputCheckpoint;
checkpoint->preloadScannerCheckpoint = lastChunkBeforeScript->preloadScannerCheckpoint;
checkpoint->unparsedInput = m_input.current().toString().isolatedCopy();
m_input.current().clear(); // FIXME: This should be passed in instead of cleared.
ASSERT(checkpoint->unparsedInput.isSafeToSendToAnotherThread());
HTMLParserThread::shared()->postTask(bind(&BackgroundHTMLParser::resumeFrom, m_backgroundParser, checkpoint.release()));
}
void HTMLDocumentParser::processParsedChunkFromBackgroundParser(PassOwnPtr<ParsedChunk> popChunk)
{
TRACE_EVENT0("webkit", "HTMLDocumentParser::processParsedChunkFromBackgroundParser");
ASSERT_WITH_SECURITY_IMPLICATION(!document()->activeParserCount());
ASSERT(!isParsingFragment());
ASSERT(!isWaitingForScripts());
ASSERT(!isStopped());
// ASSERT that this object is both attached to the Document and protected.
ASSERT(refCount() >= 2);
ASSERT(shouldUseThreading());
ASSERT(!m_tokenizer);
ASSERT(!m_token);
ASSERT(!m_lastChunkBeforeScript);
ActiveParserSession session(contextForParsingSession());
OwnPtr<ParsedChunk> chunk(popChunk);
OwnPtr<CompactHTMLTokenStream> tokens = chunk->tokens.release();
HTMLParserThread::shared()->postTask(bind(&BackgroundHTMLParser::startedChunkWithCheckpoint, m_backgroundParser, chunk->inputCheckpoint));
for (XSSInfoStream::const_iterator it = chunk->xssInfos.begin(); it != chunk->xssInfos.end(); ++it) {
m_textPosition = (*it)->m_textPosition;
m_xssAuditorDelegate.didBlockScript(**it);
if (isStopped())
break;
}
for (Vector<CompactHTMLToken>::const_iterator it = tokens->begin(); it != tokens->end(); ++it) {
ASSERT(!isWaitingForScripts());
if (!isParsingFragment()
&& document()->frame() && document()->frame()->navigationScheduler().locationChangePending()) {
// To match main-thread parser behavior (which never checks locationChangePending on the EOF path)
// we peek to see if this chunk has an EOF and process it anyway.
if (tokens->last().type() == HTMLToken::EndOfFile) {
ASSERT(m_speculations.isEmpty()); // There should never be any chunks after the EOF.
prepareToStopParsing();
}
break;
}
m_textPosition = it->textPosition();
constructTreeFromCompactHTMLToken(*it);
if (isStopped())
break;
if (isWaitingForScripts()) {
ASSERT(it + 1 == tokens->end()); // The </script> is assumed to be the last token of this bunch.
runScriptsForPausedTreeBuilder();
validateSpeculations(chunk.release());
break;
}
if (it->type() == HTMLToken::EndOfFile) {
ASSERT(it + 1 == tokens->end()); // The EOF is assumed to be the last token of this bunch.
ASSERT(m_speculations.isEmpty()); // There should never be any chunks after the EOF.
prepareToStopParsing();
break;
}
ASSERT(!m_tokenizer);
ASSERT(!m_token);
}
}
void HTMLDocumentParser::pumpPendingSpeculations()
{
// FIXME: Share this constant with the parser scheduler.
const double parserTimeLimit = 0.500;
// ASSERT that this object is both attached to the Document and protected.
ASSERT(refCount() >= 2);
// If this assert fails, you need to call validateSpeculations to make sure
// m_tokenizer and m_token don't have state that invalidates m_speculations.
ASSERT(!m_tokenizer);
ASSERT(!m_token);
ASSERT(!m_lastChunkBeforeScript);
ASSERT(!isWaitingForScripts());
ASSERT(!isStopped());
// FIXME: Pass in current input length.
InspectorInstrumentationCookie cookie = InspectorInstrumentation::willWriteHTML(document(), lineNumber().zeroBasedInt());
double startTime = currentTime();
while (!m_speculations.isEmpty()) {
processParsedChunkFromBackgroundParser(m_speculations.takeFirst());
// The order matters! If this isStopped(), isWaitingForScripts() can hit and ASSERT since
// m_document can be null which is used to decide the readiness.
if (isStopped())
break;
if (isWaitingForScripts())
break;
if (currentTime() - startTime > parserTimeLimit && !m_speculations.isEmpty()) {
m_parserScheduler->scheduleForResume();
break;
}
}
InspectorInstrumentation::didWriteHTML(cookie, lineNumber().zeroBasedInt());
}
void HTMLDocumentParser::forcePlaintextForTextDocument()
{
if (shouldUseThreading()) {
// This method is called before any data is appended, so we have to start
// the background parser ourselves.
if (!m_haveBackgroundParser)
startBackgroundParser();
HTMLParserThread::shared()->postTask(bind(&BackgroundHTMLParser::forcePlaintextForTextDocument, m_backgroundParser));
} else
m_tokenizer->setState(HTMLTokenizer::PLAINTEXTState);
}
Document* HTMLDocumentParser::contextForParsingSession()
{
// The parsing session should interact with the document only when parsing
// non-fragments. Otherwise, we might delay the load event mistakenly.
if (isParsingFragment())
return 0;
return document();
}
void HTMLDocumentParser::pumpTokenizer(SynchronousMode mode)
{
ASSERT(!isStopped());
ASSERT(!isScheduledForResume());
// ASSERT that this object is both attached to the Document and protected.
ASSERT(refCount() >= 2);
ASSERT(m_tokenizer);
ASSERT(m_token);
ASSERT(!m_haveBackgroundParser || mode == ForceSynchronous);
PumpSession session(m_pumpSessionNestingLevel, contextForParsingSession());
// We tell the InspectorInstrumentation about every pump, even if we
// end up pumping nothing. It can filter out empty pumps itself.
// FIXME: m_input.current().length() is only accurate if we
// end up parsing the whole buffer in this pump. We should pass how
// much we parsed as part of didWriteHTML instead of willWriteHTML.
InspectorInstrumentationCookie cookie = InspectorInstrumentation::willWriteHTML(document(), m_input.current().currentLine().zeroBasedInt());
m_xssAuditor.init(document(), &m_xssAuditorDelegate);
while (canTakeNextToken(mode, session) && !session.needsYield) {
if (!isParsingFragment())
m_sourceTracker.start(m_input.current(), m_tokenizer.get(), token());
if (!m_tokenizer->nextToken(m_input.current(), token()))
break;
if (!isParsingFragment()) {
m_sourceTracker.end(m_input.current(), m_tokenizer.get(), token());
// We do not XSS filter innerHTML, which means we (intentionally) fail
// http/tests/security/xssAuditor/dom-write-innerHTML.html
if (OwnPtr<XSSInfo> xssInfo = m_xssAuditor.filterToken(FilterTokenRequest(token(), m_sourceTracker, m_tokenizer->shouldAllowCDATA())))
m_xssAuditorDelegate.didBlockScript(*xssInfo);
}
constructTreeFromHTMLToken(token());
ASSERT(token().isUninitialized());
}
// Ensure we haven't been totally deref'ed after pumping. Any caller of this
// function should be holding a RefPtr to this to ensure we weren't deleted.
ASSERT(refCount() >= 1);
if (isStopped())
return;
if (session.needsYield)
m_parserScheduler->scheduleForResume();
if (isWaitingForScripts()) {
ASSERT(m_tokenizer->state() == HTMLTokenizer::DataState);
if (!m_preloadScanner) {
m_preloadScanner = adoptPtr(new HTMLPreloadScanner(m_options, document()->url(), document()->devicePixelRatio()));
m_preloadScanner->appendToEnd(m_input.current());
}
m_preloadScanner->scan(m_preloader.get(), document()->baseElementURL());
}
InspectorInstrumentation::didWriteHTML(cookie, m_input.current().currentLine().zeroBasedInt());
}
void HTMLDocumentParser::constructTreeFromHTMLToken(HTMLToken& rawToken)
{
AtomicHTMLToken token(rawToken);
// We clear the rawToken in case constructTreeFromAtomicToken
// synchronously re-enters the parser. We don't clear the token immedately
// for Character tokens because the AtomicHTMLToken avoids copying the
// characters by keeping a pointer to the underlying buffer in the
// HTMLToken. Fortunately, Character tokens can't cause us to re-enter
// the parser.
//
// FIXME: Stop clearing the rawToken once we start running the parser off
// the main thread or once we stop allowing synchronous JavaScript
// execution from parseAttribute.
if (rawToken.type() != HTMLToken::Character)
rawToken.clear();
m_treeBuilder->constructTree(&token);
if (!rawToken.isUninitialized()) {
ASSERT(rawToken.type() == HTMLToken::Character);
rawToken.clear();
}
}
void HTMLDocumentParser::constructTreeFromCompactHTMLToken(const CompactHTMLToken& compactToken)
{
AtomicHTMLToken token(compactToken);
m_treeBuilder->constructTree(&token);
}
bool HTMLDocumentParser::hasInsertionPoint()
{
// FIXME: The wasCreatedByScript() branch here might not be fully correct.
// Our model of the EOF character differs slightly from the one in
// the spec because our treatment is uniform between network-sourced
// and script-sourced input streams whereas the spec treats them
// differently.
return m_input.hasInsertionPoint() || (wasCreatedByScript() && !m_input.haveSeenEndOfFile());
}
void HTMLDocumentParser::insert(const SegmentedString& source)
{
if (isStopped())
return;
TRACE_EVENT0("webkit", "HTMLDocumentParser::insert");
// pumpTokenizer can cause this parser to be detached from the Document,
// but we need to ensure it isn't deleted yet.
RefPtr<HTMLDocumentParser> protect(this);
if (!m_tokenizer) {
ASSERT(!inPumpSession());
ASSERT(m_haveBackgroundParser || wasCreatedByScript());
m_token = adoptPtr(new HTMLToken);
m_tokenizer = HTMLTokenizer::create(m_options);
}
SegmentedString excludedLineNumberSource(source);
excludedLineNumberSource.setExcludeLineNumbers();
m_input.insertAtCurrentInsertionPoint(excludedLineNumberSource);
pumpTokenizerIfPossible(ForceSynchronous);
if (isWaitingForScripts()) {
// Check the document.write() output with a separate preload scanner as
// the main scanner can't deal with insertions.
if (!m_insertionPreloadScanner)
m_insertionPreloadScanner = adoptPtr(new HTMLPreloadScanner(m_options, document()->url(), document()->devicePixelRatio()));
m_insertionPreloadScanner->appendToEnd(source);
m_insertionPreloadScanner->scan(m_preloader.get(), document()->baseElementURL());
}
endIfDelayed();
}
void HTMLDocumentParser::startBackgroundParser()
{
ASSERT(shouldUseThreading());
ASSERT(!m_haveBackgroundParser);
m_haveBackgroundParser = true;
HTMLIdentifier::init();
RefPtr<WeakReference<BackgroundHTMLParser> > reference = WeakReference<BackgroundHTMLParser>::createUnbound();
m_backgroundParser = WeakPtr<BackgroundHTMLParser>(reference);
OwnPtr<BackgroundHTMLParser::Configuration> config = adoptPtr(new BackgroundHTMLParser::Configuration);
config->options = m_options;
config->parser = m_weakFactory.createWeakPtr();
config->xssAuditor = adoptPtr(new XSSAuditor);
config->xssAuditor->init(document(), &m_xssAuditorDelegate);
config->preloadScanner = adoptPtr(new TokenPreloadScanner(document()->url().copy(), document()->devicePixelRatio()));
ASSERT(config->xssAuditor->isSafeToSendToAnotherThread());
ASSERT(config->preloadScanner->isSafeToSendToAnotherThread());
HTMLParserThread::shared()->postTask(bind(&BackgroundHTMLParser::create, reference.release(), config.release()));
}
void HTMLDocumentParser::stopBackgroundParser()
{
ASSERT(shouldUseThreading());
ASSERT(m_haveBackgroundParser);
m_haveBackgroundParser = false;
HTMLParserThread::shared()->postTask(bind(&BackgroundHTMLParser::stop, m_backgroundParser));
m_weakFactory.revokeAll();
}
void HTMLDocumentParser::append(PassRefPtr<StringImpl> inputSource)
{
if (isStopped())
return;
if (shouldUseThreading()) {
if (!m_haveBackgroundParser)
startBackgroundParser();
ASSERT(inputSource->hasOneRef());
TRACE_EVENT1("net", "HTMLDocumentParser::append", "size", inputSource->length());
// NOTE: Important that the String temporary is destroyed before we post the task
// otherwise the String could call deref() on a StringImpl now owned by the background parser.
// We would like to ASSERT(closure.arg3()->hasOneRef()) but sadly the args are private.
Closure closure = bind(&BackgroundHTMLParser::append, m_backgroundParser, String(inputSource));
HTMLParserThread::shared()->postTask(closure);
return;
}
// pumpTokenizer can cause this parser to be detached from the Document,
// but we need to ensure it isn't deleted yet.
RefPtr<HTMLDocumentParser> protect(this);
TRACE_EVENT1("net", "HTMLDocumentParser::append", "size", inputSource->length());
String source(inputSource);
if (m_preloadScanner) {
if (m_input.current().isEmpty() && !isWaitingForScripts()) {
// We have parsed until the end of the current input and so are now moving ahead of the preload scanner.
// Clear the scanner so we know to scan starting from the current input point if we block again.
m_preloadScanner.clear();
} else {
m_preloadScanner->appendToEnd(source);
if (isWaitingForScripts())
m_preloadScanner->scan(m_preloader.get(), document()->baseElementURL());
}
}
m_input.appendToEnd(source);
if (inPumpSession()) {
// We've gotten data off the network in a nested write.
// We don't want to consume any more of the input stream now. Do
// not worry. We'll consume this data in a less-nested write().
return;
}
// A couple pinToMainThread() callers require synchronous parsing, but can't
// easily use the insert() method, so we hack append() for them to be synchronous.
// javascript: url handling is one such caller.
// FIXME: This is gross, and we should separate the concept of synchronous parsing
// from insert() so that only document.write() uses insert.
if (m_isPinnedToMainThread)
pumpTokenizerIfPossible(ForceSynchronous);
else
pumpTokenizerIfPossible(AllowYield);
endIfDelayed();
}
void HTMLDocumentParser::end()
{
ASSERT(!isDetached());
ASSERT(!isScheduledForResume());
if (m_haveBackgroundParser)
stopBackgroundParser();
// Informs the the rest of WebCore that parsing is really finished (and deletes this).
m_treeBuilder->finished();
}
void HTMLDocumentParser::attemptToRunDeferredScriptsAndEnd()
{
ASSERT(isStopping());
// FIXME: It may not be correct to disable this for the background parser.
// That means hasInsertionPoint() may not be correct in some cases.
ASSERT(!hasInsertionPoint() || m_haveBackgroundParser);
if (m_scriptRunner && !m_scriptRunner->executeScriptsWaitingForParsing())
return;
end();
}
void HTMLDocumentParser::attemptToEnd()
{
// finish() indicates we will not receive any more data. If we are waiting on
// an external script to load, we can't finish parsing quite yet.
if (shouldDelayEnd()) {
m_endWasDelayed = true;
return;
}
prepareToStopParsing();
}
void HTMLDocumentParser::endIfDelayed()
{
// If we've already been detached, don't bother ending.
if (isDetached())
return;
if (!m_endWasDelayed || shouldDelayEnd())
return;
m_endWasDelayed = false;
prepareToStopParsing();
}
void HTMLDocumentParser::finish()
{
// FIXME: We should ASSERT(!m_parserStopped) here, since it does not
// makes sense to call any methods on DocumentParser once it's been stopped.
// However, FrameLoader::stop calls DocumentParser::finish unconditionally.
// Empty documents never got an append() call, and thus have never started
// a background parser. In those cases, we ignore shouldUseThreading()
// and fall through to the non-threading case.
if (m_haveBackgroundParser) {
if (!m_input.haveSeenEndOfFile())
m_input.closeWithoutMarkingEndOfFile();
HTMLParserThread::shared()->postTask(bind(&BackgroundHTMLParser::finish, m_backgroundParser));
return;
}
if (!m_tokenizer) {
ASSERT(!m_token);
// We're finishing before receiving any data. Rather than booting up
// the background parser just to spin it down, we finish parsing
// synchronously.
m_token = adoptPtr(new HTMLToken);
m_tokenizer = HTMLTokenizer::create(m_options);
}
// We're not going to get any more data off the network, so we tell the
// input stream we've reached the end of file. finish() can be called more
// than once, if the first time does not call end().
if (!m_input.haveSeenEndOfFile())
m_input.markEndOfFile();
attemptToEnd();
}
bool HTMLDocumentParser::isExecutingScript() const
{
if (!m_scriptRunner)
return false;
return m_scriptRunner->isExecutingScript();
}
OrdinalNumber HTMLDocumentParser::lineNumber() const
{
if (m_haveBackgroundParser)
return m_textPosition.m_line;
return m_input.current().currentLine();
}
TextPosition HTMLDocumentParser::textPosition() const
{
if (m_haveBackgroundParser)
return m_textPosition;
const SegmentedString& currentString = m_input.current();
OrdinalNumber line = currentString.currentLine();
OrdinalNumber column = currentString.currentColumn();
return TextPosition(line, column);
}
bool HTMLDocumentParser::isWaitingForScripts() const
{
// When the TreeBuilder encounters a </script> tag, it returns to the HTMLDocumentParser
// where the script is transfered from the treebuilder to the script runner.
// The script runner will hold the script until its loaded and run. During
// any of this time, we want to count ourselves as "waiting for a script" and thus
// run the preload scanner, as well as delay completion of parsing.
bool treeBuilderHasBlockingScript = m_treeBuilder->hasParserBlockingScript();
bool scriptRunnerHasBlockingScript = m_scriptRunner && m_scriptRunner->hasParserBlockingScript();
// Since the parser is paused while a script runner has a blocking script, it should
// never be possible to end up with both objects holding a blocking script.
ASSERT(!(treeBuilderHasBlockingScript && scriptRunnerHasBlockingScript));
// If either object has a blocking script, the parser should be paused.
return treeBuilderHasBlockingScript || scriptRunnerHasBlockingScript;
}
void HTMLDocumentParser::resumeParsingAfterScriptExecution()
{
ASSERT(!isExecutingScript());
ASSERT(!isWaitingForScripts());
if (m_haveBackgroundParser) {
validateSpeculations(m_lastChunkBeforeScript.release());
ASSERT(!m_lastChunkBeforeScript);
// processParsedChunkFromBackgroundParser can cause this parser to be detached from the Document,
// but we need to ensure it isn't deleted yet.
RefPtr<HTMLDocumentParser> protect(this);
pumpPendingSpeculations();
return;
}
m_insertionPreloadScanner.clear();
pumpTokenizerIfPossible(AllowYield);
endIfDelayed();
}
void HTMLDocumentParser::watchForLoad(Resource* resource)
{
ASSERT(!resource->isLoaded());
// addClient would call notifyFinished if the load were complete.
// Callers do not expect to be re-entered from this call, so they should
// not an already-loaded Resource.
resource->addClient(this);
}
void HTMLDocumentParser::stopWatchingForLoad(Resource* resource)
{
resource->removeClient(this);
}
void HTMLDocumentParser::appendCurrentInputStreamToPreloadScannerAndScan()
{
ASSERT(m_preloadScanner);
m_preloadScanner->appendToEnd(m_input.current());
m_preloadScanner->scan(m_preloader.get(), document()->baseElementURL());
}
void HTMLDocumentParser::notifyFinished(Resource* cachedResource)
{
// pumpTokenizer can cause this parser to be detached from the Document,
// but we need to ensure it isn't deleted yet.
RefPtr<HTMLDocumentParser> protect(this);
ASSERT(m_scriptRunner);
ASSERT(!isExecutingScript());
if (isStopping()) {
attemptToRunDeferredScriptsAndEnd();
return;
}
m_scriptRunner->executeScriptsWaitingForLoad(cachedResource);
if (!isWaitingForScripts())
resumeParsingAfterScriptExecution();
}
void HTMLDocumentParser::executeScriptsWaitingForResources()
{
// Document only calls this when the Document owns the DocumentParser
// so this will not be called in the DocumentFragment case.
ASSERT(m_scriptRunner);
// Ignore calls unless we have a script blocking the parser waiting on a
// stylesheet load. Otherwise we are currently parsing and this
// is a re-entrant call from encountering a </ style> tag.
if (!m_scriptRunner->hasScriptsWaitingForResources())
return;
// pumpTokenizer can cause this parser to be detached from the Document,
// but we need to ensure it isn't deleted yet.
RefPtr<HTMLDocumentParser> protect(this);
m_scriptRunner->executeScriptsWaitingForResources();
if (!isWaitingForScripts())
resumeParsingAfterScriptExecution();
}
void HTMLDocumentParser::parseDocumentFragment(const String& source, DocumentFragment* fragment, Element* contextElement, ParserContentPolicy parserContentPolicy)
{
RefPtr<HTMLDocumentParser> parser = HTMLDocumentParser::create(fragment, contextElement, parserContentPolicy);
parser->insert(source); // Use insert() so that the parser will not yield.
parser->finish();
ASSERT(!parser->processingData()); // Make sure we're done. <rdar://problem/3963151>
parser->detach(); // Allows ~DocumentParser to assert it was detached before destruction.
}
void HTMLDocumentParser::suspendScheduledTasks()
{
if (m_parserScheduler)
m_parserScheduler->suspend();
}
void HTMLDocumentParser::resumeScheduledTasks()
{
if (m_parserScheduler)
m_parserScheduler->resume();
}
}