Building High P erformance JScript Applications

1. PC53 BuildingHigh PerformanceJScriptApplications  Sameer Chabungbam Program Manager Microsoft Corporation

2. Agenda • What affects Script performance? • The IE8 JScript Profiler • Native JSON Support

3. IE8 Browser Subsystem Internet Explorer HTML Parser Layout Rendering JScript Network/OS IE8 Browser Subsystem

4. Subsystem Timing In IE8

5. demo IE8 JScript Profiler

6. IE8 JScript Profiler • Uses script engine instrumentation • Export data to CSV • Shows calls to JScript Built-in methods • Handles anonymous functions var Shape = { Area : function (){...} //anonymous function 1}; Foo = function (){...} //anonymous function 2

7. IE8 JScript ProfilerArchitecture Host (Internet Explorer) • Host creates the script engine(s) • Script Engine creates Logger when profiling is enabled • Logger handles callbacks from the script engine • Profiler Core collects and analyzes the performance data • Profiler GUI displays the performance report Script Engine Profiler GUI Logger Profiler Core

8. IE8 JScript Profiler APIIActiveScriptProfilerControl Host (Internet Explorer) • Implemented by Script Engines • Methods • StartProfiling • StopProfiling • SetProfilerEventMask Script Engine Profiler GUI IActiveScriptProfilerControl Logger Profiler Core

9. IE8 JScript Profiler APIIActiveScriptProfilerCallback Host (Internet Explorer) • Implemented by Profile Logger • Handles callbacks from the script engine • Methods • Initialize • Shutdown • ScriptCompiled • FunctionCompiled • OnFunctionEnter • OnFunctionExit Script Engine Profiler GUI IActiveScriptProfilerCallback IActiveScriptProfilerControl Logger Profiler Core

10. Native JSON Support • Simple • Javascript like syntax { "name“ : "Sameer Chabungbam", "email" : "sameerch@microsoft.com", "phone" : [ "+91 40 669 42615", "+91 9949 75 4546" ] }

11. demo Native JSON

12. Native JSON Support • Fast • Secure • ECMAScript “3.1” Proposal: • “JSON” is a new Built-in Object • JSON.parse(jsontext) • Returns a JScript value – an Object or Array • JSON.stringify(value) • Returns a JSON string

13. Other Enhancements • CSS Selector API • Mutable DOM prototype • Data URI

14. Resources • Email: sameerch@microsoft.com • IE Blogs http://blogs.msdn.com/ie • JScript Blogs http://blogs.msdn.com/jscript • MSDN Documentation • Profiler • JSON • IE8 Beta 2 http://microsoft.com/ie/ie8 • JSON http://www.json.org/

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16. Q&A Please use the microphones provided

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