Initial import.

1 files changed, 137 insertions, 0 deletions

diff --git a/chromium/third_party/WebKit/Source/core/html/parser/HTMLParserScheduler.cpp b/chromium/third_party/WebKit/Source/core/html/parser/HTMLParserScheduler.cpp
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index 00000000000..b5b38896df4
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+++ b/chromium/third_party/WebKit/Source/core/html/parser/HTMLParserScheduler.cpp
@@ -0,0 +1,137 @@
+/*
+ * 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/HTMLParserScheduler.h"
+
+#include "core/dom/Document.h"
+#include "core/html/parser/HTMLDocumentParser.h"
+#include "core/page/FrameView.h"
+
+namespace WebCore {
+
+// parserChunkSize 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.
+const int HTMLParserScheduler::parserChunkSize = 4096;
+
+// parserTimeLimit is the seconds the parser will run in one write() call
+// before yielding. Inline <script> execution can cause it to exceed the limit.
+const double HTMLParserScheduler::parserTimeLimit = 0.2;
+
+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_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.
+    // FIXME: We should fix this by reducing the max-parse-time instead of
+    // artificially forcing the parser to yield agressively before first layout.
+    if (m_parser->document()->shouldParserYieldAgressivelyBeforeScriptExecution()) {
+        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->shouldParserYieldAgressivelyBeforeScriptExecution())
+        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);
+}
+
+}