Subj : Re: Rhino: Obtaining a list of script functions
To   : Attila Szegedi
From : Igor Bukanov
Date : Fri Oct 15 2004 10:22 pm

Attila Szegedi wrote:
 > Actually, I have since found a way to enumerate DebuggableScript
 > objects  through Debugger.handleCompilationDone() (I'm talking about 1.6
 > codebase  here).
 >
 > My problem is that the object behind the DebuggableScript is not the
 > InterpretedFunction object, but rather its InterpretedData.
 >
 > I have a script execution engine that serializes lots of script
 > execution  contexts when they are inactive for a period of time - this
 > is used in  conjunction with continuation support in 1.6 - then later
 > loads them and  continues execution. The ability to stub the
 > InterpretedFunction instances
 >  in serialization would allow me to eliminate redundancy at runtime - if
 > I  have 2000 deserialized states executing the same script, each
 > InterpetedFunction is deserialized and duplicated in memory 2000 times.
 >
 > Now granted, stubbing InterpetedData (which is the only thing I can
 > enumerate through debugger.handleCompilationDone()) does help eliminate
 > some of the redundancy - all the deserialized states can use single
 > instance/function, but if I could enumerate (and therfore stub)
 > InterpretedFunction
 > instances, that'd be the real deal.

Script instances do not hold any InterpretedFunction objects 
representing JS functions since they are created during Script.exec. 
Similarly the nested functions are not wrapped into InterpretedFunction 
until the parent function is executed.

In addition function objects in JS are not read only and if you would 
ignore modifications of InterpretedFunction during serialize/desirialize 
then you would break JS code like

ContructorName.prototype = ...

Also note that Rhino CVS contains Context.getDebuggableView that allows 
to get DebuggableScript from Script without implementing Debugger interface.

Regards, Igor

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