--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/WebCore/html/HTMLParserScheduler.cpp	Fri Sep 17 09:02:29 2010 +0300
@@ -0,0 +1,95 @@
+/*
+ * 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 "FrameView.h" // Only for isLayoutTimerActive
+#include "HTMLDocumentParser.h"
+#include "Document.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 excede 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;
+}
+
+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)
+{
+}
+
+HTMLParserScheduler::~HTMLParserScheduler()
+{
+    m_continueNextChunkTimer.stop();
+}
+
+// FIXME: This belongs on Document.
+static bool isLayoutTimerActive(Document* doc)
+{
+    ASSERT(doc);
+    return doc->view() && doc->view()->layoutPending() && !doc->minimumLayoutDelay();
+}
+
+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 (isLayoutTimerActive(m_parser->document())) {
+        m_continueNextChunkTimer.startOneShot(0);
+        return;
+    }
+    m_parser->resumeParsingAfterYield();
+}
+
+}