--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/WebCore/html/HTMLDocumentParser.cpp	Fri Sep 17 09:02:29 2010 +0300
@@ -0,0 +1,429 @@
+/*
+ * 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 "HTMLDocumentParser.h"
+
+#include "DocumentFragment.h"
+#include "Element.h"
+#include "Frame.h"
+#include "HTMLParserScheduler.h"
+#include "HTMLTokenizer.h"
+#include "HTMLPreloadScanner.h"
+#include "HTMLScriptRunner.h"
+#include "HTMLTreeBuilder.h"
+#include "HTMLDocument.h"
+#include "XSSAuditor.h"
+#include <wtf/CurrentTime.h>
+
+#if ENABLE(INSPECTOR)
+#include "InspectorTimelineAgent.h"
+#endif
+
+namespace WebCore {
+
+namespace {
+
+class NestingLevelIncrementer : public Noncopyable {
+public:
+    explicit NestingLevelIncrementer(int& counter)
+        : m_counter(&counter)
+    {
+        ++(*m_counter);
+    }
+
+    ~NestingLevelIncrementer()
+    {
+        --(*m_counter);
+    }
+
+private:
+    int* m_counter;
+};
+
+} // namespace
+
+HTMLDocumentParser::HTMLDocumentParser(HTMLDocument* document, bool reportErrors)
+    : ScriptableDocumentParser(document)
+    , m_tokenizer(new HTMLTokenizer)
+    , m_scriptRunner(new HTMLScriptRunner(document, this))
+    , m_treeBuilder(new HTMLTreeBuilder(m_tokenizer.get(), document, reportErrors))
+    , m_parserScheduler(new HTMLParserScheduler(this))
+    , m_endWasDelayed(false)
+    , m_writeNestingLevel(0)
+{
+    begin();
+}
+
+// FIXME: Member variables should be grouped into self-initializing structs to
+// minimize code duplication between these constructors.
+HTMLDocumentParser::HTMLDocumentParser(DocumentFragment* fragment, FragmentScriptingPermission scriptingPermission)
+    : ScriptableDocumentParser(fragment->document())
+    , m_tokenizer(new HTMLTokenizer)
+    , m_treeBuilder(new HTMLTreeBuilder(m_tokenizer.get(), fragment, scriptingPermission))
+    , m_endWasDelayed(false)
+    , m_writeNestingLevel(0)
+{
+    begin();
+}
+
+HTMLDocumentParser::~HTMLDocumentParser()
+{
+    // FIXME: We'd like to ASSERT that normal operation of this class clears
+    // out any delayed actions, but we can't because we're unceremoniously
+    // deleted.  If there were a required call to some sort of cancel function,
+    // then we could ASSERT some invariants here.
+}
+
+void HTMLDocumentParser::begin()
+{
+    // FIXME: Should we reset the tokenizer?
+}
+
+void HTMLDocumentParser::stopParsing()
+{
+    DocumentParser::stopParsing();
+    m_parserScheduler.clear(); // Deleting the scheduler will clear any timers.
+}
+
+bool HTMLDocumentParser::processingData() const
+{
+    return isScheduledForResume() || inWrite();
+}
+
+void HTMLDocumentParser::pumpTokenizerIfPossible(SynchronousMode mode)
+{
+    if (m_parserStopped || m_treeBuilder->isPaused())
+        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()
+{
+    // We should never be here unless we can pump immediately.  Call pumpTokenizer()
+    // directly so that ASSERTS will fire if we're wrong.
+    pumpTokenizer(AllowYield);
+}
+
+bool HTMLDocumentParser::runScriptsForPausedTreeBuilder()
+{
+    ASSERT(m_treeBuilder->isPaused());
+
+    int scriptStartLine = 0;
+    RefPtr<Element> scriptElement = m_treeBuilder->takeScriptToProcess(scriptStartLine);
+    // We will not have a scriptRunner when parsing a DocumentFragment.
+    if (!m_scriptRunner)
+        return true;
+    return m_scriptRunner->execute(scriptElement.release(), scriptStartLine);
+}
+
+void HTMLDocumentParser::pumpTokenizer(SynchronousMode mode)
+{
+    ASSERT(!m_parserStopped);
+    ASSERT(!m_treeBuilder->isPaused());
+    ASSERT(!isScheduledForResume());
+
+    // We tell the InspectorTimelineAgent about every pump, even if we
+    // end up pumping nothing.  It can filter out empty pumps itself.
+    willPumpLexer();
+
+    HTMLParserScheduler::PumpSession session;
+    // FIXME: This loop body has is now too long and needs cleanup.
+    while (mode == ForceSynchronous || (!m_parserStopped && m_parserScheduler->shouldContinueParsing(session))) {
+        if (!m_tokenizer->nextToken(m_input.current(), m_token))
+            break;
+
+        m_treeBuilder->constructTreeFromToken(m_token);
+        m_token.clear();
+
+        // The parser will pause itself when waiting on a script to load or run.
+        if (!m_treeBuilder->isPaused())
+            continue;
+
+        // If we're paused waiting for a script, we try to execute scripts before continuing.
+        bool shouldContinueParsing = runScriptsForPausedTreeBuilder();
+        m_treeBuilder->setPaused(!shouldContinueParsing);
+        if (!shouldContinueParsing)
+            break;
+    }
+
+    if (isWaitingForScripts()) {
+        ASSERT(m_tokenizer->state() == HTMLTokenizer::DataState);
+        if (!m_preloadScanner) {
+            m_preloadScanner.set(new HTMLPreloadScanner(m_document));
+            m_preloadScanner->appendToEnd(m_input.current());
+        }
+        m_preloadScanner->scan();
+    }
+
+    didPumpLexer();
+}
+
+void HTMLDocumentParser::willPumpLexer()
+{
+#if ENABLE(INSPECTOR)
+    // 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.
+    if (InspectorTimelineAgent* timelineAgent = m_document->inspectorTimelineAgent())
+        timelineAgent->willWriteHTML(m_input.current().length(), m_tokenizer->lineNumber());
+#endif
+}
+
+void HTMLDocumentParser::didPumpLexer()
+{
+#if ENABLE(INSPECTOR)
+    if (InspectorTimelineAgent* timelineAgent = m_document->inspectorTimelineAgent())
+        timelineAgent->didWriteHTML(m_tokenizer->lineNumber());
+#endif
+}
+
+void HTMLDocumentParser::insert(const SegmentedString& source)
+{
+    if (m_parserStopped)
+        return;
+
+    if (m_scriptRunner && !m_scriptRunner->inScriptExecution() && m_input.haveSeenEndOfFile()) {
+        // document.write was called without a current insertion point.
+        // According to the spec, we're supposed to implicitly open the
+        // document.  Unfortunately, that behavior isn't sufficiently compatible
+        // with the web.  The working group is mulling over what exactly to
+        // do.  In the meantime, we're going to try one of the potential
+        // solutions, which is to ignore the write.
+        // http://www.w3.org/Bugs/Public/show_bug.cgi?id=9767
+        return;
+    }
+
+    {
+        NestingLevelIncrementer nestingLevelIncrementer(m_writeNestingLevel);
+
+        SegmentedString excludedLineNumberSource(source);
+        excludedLineNumberSource.setExcludeLineNumbers();
+        m_input.insertAtCurrentInsertionPoint(excludedLineNumberSource);
+        pumpTokenizerIfPossible(ForceSynchronous);
+    }
+
+    endIfDelayed();
+}
+
+void HTMLDocumentParser::append(const SegmentedString& source)
+{
+    if (m_parserStopped)
+        return;
+
+    {
+        NestingLevelIncrementer nestingLevelIncrementer(m_writeNestingLevel);
+
+        m_input.appendToEnd(source);
+        if (m_preloadScanner)
+            m_preloadScanner->appendToEnd(source);
+
+        if (m_writeNestingLevel > 1) {
+            // 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;
+        }
+
+        pumpTokenizerIfPossible(AllowYield);
+    }
+
+    endIfDelayed();
+}
+
+void HTMLDocumentParser::end()
+{
+    ASSERT(!isScheduledForResume());
+    // NOTE: This pump should only ever emit buffered character tokens,
+    // so ForceSynchronous vs. AllowYield should be meaningless.
+    pumpTokenizerIfPossible(ForceSynchronous);
+
+    // Informs the the rest of WebCore that parsing is really finished (and deletes this).
+    m_treeBuilder->finished();
+}
+
+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;
+    }
+    end();
+}
+
+void HTMLDocumentParser::endIfDelayed()
+{
+    if (!m_endWasDelayed || shouldDelayEnd())
+        return;
+
+    m_endWasDelayed = false;
+    end();
+}
+
+void HTMLDocumentParser::finish()
+{
+    // 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::finishWasCalled()
+{
+    return m_input.haveSeenEndOfFile();
+}
+
+// This function is virtual and just for the DocumentParser interface.
+bool HTMLDocumentParser::isExecutingScript() const
+{
+    return inScriptExecution();
+}
+
+// This function is non-virtual and used throughout the implementation.
+bool HTMLDocumentParser::inScriptExecution() const
+{
+    if (!m_scriptRunner)
+        return false;
+    return m_scriptRunner->inScriptExecution();
+}
+
+int HTMLDocumentParser::lineNumber() const
+{
+    return m_tokenizer->lineNumber();
+}
+
+int HTMLDocumentParser::columnNumber() const
+{
+    return m_tokenizer->columnNumber();
+}
+
+LegacyHTMLTreeBuilder* HTMLDocumentParser::htmlTreeBuilder() const
+{
+    return m_treeBuilder->legacyTreeBuilder();
+}
+
+bool HTMLDocumentParser::isWaitingForScripts() const
+{
+    return m_treeBuilder->isPaused();
+}
+
+void HTMLDocumentParser::resumeParsingAfterScriptExecution()
+{
+    ASSERT(!inScriptExecution());
+    ASSERT(!m_treeBuilder->isPaused());
+
+    m_preloadScanner.clear();
+    pumpTokenizerIfPossible(AllowYield);
+    endIfDelayed();
+}
+
+void HTMLDocumentParser::watchForLoad(CachedResource* cachedScript)
+{
+    ASSERT(!cachedScript->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 CachedResource.
+    cachedScript->addClient(this);
+}
+
+void HTMLDocumentParser::stopWatchingForLoad(CachedResource* cachedScript)
+{
+    cachedScript->removeClient(this);
+}
+
+bool HTMLDocumentParser::shouldLoadExternalScriptFromSrc(const AtomicString& srcValue)
+{
+    if (!xssAuditor())
+        return true;
+    return xssAuditor()->canLoadExternalScriptFromSrc(srcValue);
+}
+
+void HTMLDocumentParser::notifyFinished(CachedResource* cachedResource)
+{
+    ASSERT(m_scriptRunner);
+    ASSERT(!inScriptExecution());
+    ASSERT(m_treeBuilder->isPaused());
+    // Note: We only ever wait on one script at a time, so we always know this
+    // is the one we were waiting on and can un-pause the tree builder.
+    m_treeBuilder->setPaused(false);
+    bool shouldContinueParsing = m_scriptRunner->executeScriptsWaitingForLoad(cachedResource);
+    m_treeBuilder->setPaused(!shouldContinueParsing);
+    if (shouldContinueParsing)
+        resumeParsingAfterScriptExecution();
+}
+
+void HTMLDocumentParser::executeScriptsWaitingForStylesheets()
+{
+    // 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->hasScriptsWaitingForStylesheets())
+        return;
+    ASSERT(!m_scriptRunner->inScriptExecution());
+    ASSERT(m_treeBuilder->isPaused());
+    // Note: We only ever wait on one script at a time, so we always know this
+    // is the one we were waiting on and can un-pause the tree builder.
+    m_treeBuilder->setPaused(false);
+    bool shouldContinueParsing = m_scriptRunner->executeScriptsWaitingForStylesheets();
+    m_treeBuilder->setPaused(!shouldContinueParsing);
+    if (shouldContinueParsing)
+        resumeParsingAfterScriptExecution();
+}
+
+ScriptController* HTMLDocumentParser::script() const
+{
+    return m_document->frame() ? m_document->frame()->script() : 0;
+}
+
+void HTMLDocumentParser::parseDocumentFragment(const String& source, DocumentFragment* fragment, FragmentScriptingPermission scriptingPermission)
+{
+    HTMLDocumentParser parser(fragment, scriptingPermission);
+    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>
+}
+
+}