Re: [Jython-users] Embedding question!

[Robert W. B. <rb...@di...>]

Hello Siva,

On Thu, 9 Aug 2001, Siva Subramanian Somu wrote:
> Hi,
> 	I know a zillion questions would have been asked about embedding jython in
> java,
> but I need to know how to do this. The problem is as follows
>
> I have a java application which will create some number of jython
> interpreters and each one
> of the created interpreters will be executing a same script over and over
> again. So I don't
> want the interpreter to waste time parsing the script again and again. So I
> want to know
> is there someway for me to avoid parsing. Is there someway I could save the
> parsed code
> in binary form in memory and get Jython to use that? Any help regarding this
> question
> would be greatly appreciated.
>
> thanks,
> Siva

Option 1- write it so that you can run the script once and only apply a
callable object each subsequent need.  Here's Pseudo-code:

interp.execfile("myscriptfile");
for (int i=0; i < 1000; i++) {
    interp.exec("function_in_myscriptfile()");
}

This execs the file once, and subsequently only invokes a callable object
defined in the script. Care with module global vars is required.

Option 2- compile the script once and use the compiled bytecode for each
subsequent interp.exec().  To do this, use the built-in compile function
shown in the following pseudocode:

//this would really be file contents instead of a PyString
PyString mycode = new PyString("print 'Hello World'");
PyCode code = __builtin__.compile(mycode, "<>", "exec");
for (int i=0; i<1000; i++) {
    interp.exec(code);
}

Executing the code object is lower overhead than the string.


Let me know if larger examples would be helpful.


Cheers,
Robert