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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 "HTMLParserScheduler.h"
#include "Document.h"
#include "FrameView.h"
#include "HTMLDocumentParser.h"
#include "Page.h"
// defaultParserChunkSize is used to define how many tokens the parser will
// process before checking against parserTimeLimit and possibly yielding.
// This is a performance optimization to prevent checking after every token.
static const int defaultParserChunkSize = 4096;
// defaultParserTimeLimit is the seconds the parser will run in one write() call
// before yielding. Inline <script> execution can cause it to exceed the limit.
// FIXME: We would like this value to be 0.2.
static const double defaultParserTimeLimit = 0.500;
namespace WebCore {
static double parserTimeLimit(Page* page)
{
// We're using the poorly named customHTMLTokenizerTimeDelay setting.
if (page && page->hasCustomHTMLTokenizerTimeDelay())
return page->customHTMLTokenizerTimeDelay();
return defaultParserTimeLimit;
}
static int parserChunkSize(Page* page)
{
// FIXME: We may need to divide the value from customHTMLTokenizerChunkSize
// by some constant to translate from the "character" based behavior of the
// old LegacyHTMLDocumentParser to the token-based behavior of this parser.
if (page && page->hasCustomHTMLTokenizerChunkSize())
return page->customHTMLTokenizerChunkSize();
return defaultParserChunkSize;
}
ActiveParserSession::ActiveParserSession(Document* document)
: m_document(document)
{
if (!m_document)
return;
m_document->incrementActiveParserCount();
}
ActiveParserSession::~ActiveParserSession()
{
if (!m_document)
return;
m_document->decrementActiveParserCount();
}
PumpSession::PumpSession(unsigned& nestingLevel, Document* document)
: NestingLevelIncrementer(nestingLevel)
, ActiveParserSession(document)
// Setting processedTokens to INT_MAX causes us to check for yields
// after any token during any parse where yielding is allowed.
// At that time we'll initialize startTime.
, processedTokens(INT_MAX)
, startTime(0)
, needsYield(false)
, didSeeScript(false)
{
}
PumpSession::~PumpSession()
{
}
HTMLParserScheduler::HTMLParserScheduler(HTMLDocumentParser* parser)
: m_parser(parser)
, m_parserTimeLimit(parserTimeLimit(m_parser->document()->page()))
, m_parserChunkSize(parserChunkSize(m_parser->document()->page()))
, m_continueNextChunkTimer(this, &HTMLParserScheduler::continueNextChunkTimerFired)
, m_isSuspendedWithActiveTimer(false)
{
}
HTMLParserScheduler::~HTMLParserScheduler()
{
m_continueNextChunkTimer.stop();
}
void HTMLParserScheduler::continueNextChunkTimerFired(Timer<HTMLParserScheduler>* timer)
{
ASSERT_UNUSED(timer, timer == &m_continueNextChunkTimer);
// FIXME: The timer class should handle timer priorities instead of this code.
// If a layout is scheduled, wait again to let the layout timer run first.
if (m_parser->document()->isLayoutTimerActive()) {
m_continueNextChunkTimer.startOneShot(0);
return;
}
m_parser->resumeParsingAfterYield();
}
void HTMLParserScheduler::checkForYieldBeforeScript(PumpSession& session)
{
// If we've never painted before and a layout is pending, yield prior to running
// scripts to give the page a chance to paint earlier.
Document* document = m_parser->document();
bool needsFirstPaint = document->view() && !document->view()->hasEverPainted();
if (needsFirstPaint && document->isLayoutTimerActive())
session.needsYield = true;
session.didSeeScript = true;
}
void HTMLParserScheduler::scheduleForResume()
{
m_continueNextChunkTimer.startOneShot(0);
}
void HTMLParserScheduler::suspend()
{
ASSERT(!m_isSuspendedWithActiveTimer);
if (!m_continueNextChunkTimer.isActive())
return;
m_isSuspendedWithActiveTimer = true;
m_continueNextChunkTimer.stop();
}
void HTMLParserScheduler::resume()
{
ASSERT(!m_continueNextChunkTimer.isActive());
if (!m_isSuspendedWithActiveTimer)
return;
m_isSuspendedWithActiveTimer = false;
m_continueNextChunkTimer.startOneShot(0);
}
}
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