WebCore/html/HTMLParserScheduler.h
changeset 0 4f2f89ce4247
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/WebCore/html/HTMLParserScheduler.h	Fri Sep 17 09:02:29 2010 +0300
@@ -0,0 +1,84 @@
+/*
+ * 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.
+ */
+
+#ifndef HTMLParserScheduler_h
+#define HTMLParserScheduler_h
+
+#include "Timer.h"
+#include <wtf/CurrentTime.h>
+#include <wtf/Noncopyable.h>
+
+namespace WebCore {
+
+class HTMLDocumentParser;
+
+class HTMLParserScheduler :  public Noncopyable {
+public:
+    HTMLParserScheduler(HTMLDocumentParser*);
+    ~HTMLParserScheduler();
+
+    struct PumpSession {
+        PumpSession()
+            : processedTokens(0)
+            , startTime(currentTime())
+        {
+        }
+
+        int processedTokens;
+        double startTime;
+    };
+
+    // Inline as this is called after every token in the parser.
+    bool shouldContinueParsing(PumpSession& session)
+    {
+        if (session.processedTokens > m_parserChunkSize) {
+            session.processedTokens = 0;
+            double elapsedTime = currentTime() - session.startTime;
+            if (elapsedTime > m_parserTimeLimit) {
+                // Schedule the parser to continue and yield from the parser.
+                m_continueNextChunkTimer.startOneShot(0);
+                return false;
+            }
+        }
+
+        ++session.processedTokens;
+        return true;
+    }
+
+    bool isScheduledForResume() const { return m_continueNextChunkTimer.isActive(); }
+
+private:
+    void continueNextChunkTimerFired(Timer<HTMLParserScheduler>*);
+
+    HTMLDocumentParser* m_parser;
+
+    double m_parserTimeLimit;
+    int m_parserChunkSize;
+    Timer<HTMLParserScheduler> m_continueNextChunkTimer;
+};
+
+}
+
+#endif