Subj : Re: Implementation Questions
To   : "Igor Bukanov" <igor@fastmail.fm>
From : mike@electrotank.com (Michael Grundvig)
Date : Sat May 10 2003 02:13 pm

Sorry I didn't include any code the first time. When the ScriptPlugin is
instantiated, it does this (among other things):

Script compiledScript = cx.compileReader(_scope, reader, script, 1, null);
compiledScript.exec(cx, _scope);
_pluginRequestFunction = (Function)_scope.get("pluginRequest", _scope);

Then for each request, I just call:

Context cx = Context.enter();
String output = null;
try {
     Object results = function.call(cx, _scope, _scope, functionArguments);
     output = Context.toString(results);
} finally {
     Context.exit();
}

Is this a good way to do it? What would be a better way? Thanks!

Mike

----- Original Message -----
From: "Igor Bukanov" <igor@fastmail.fm>
Newsgroups: netscape.public.mozilla.jseng
To: <mozilla-jseng@mozilla.org>; "Michael Grundvig" <mike@electrotank.com>
Sent: Friday, May 09, 2003 11:01 AM
Subject: Re: Implementation Questions


> Michael Grundvig wrote:
> > Hi all! First off, I want to thank everyone who has worked on Rhino,
it's
> > great! We have been able to use it with great success.
> >
> > The purpose of this email is to ask about how to implement Rhino
effectivly.
> > We have a server that supports the concept of plugins. A plugin is
> > registered by a user and it contains a name, script on the file system
and
> > some initilization parameters. An object called ScriptPlugin is used for
all
> > this.
> >
> > When the server is restarted, it will load in all the plugins and init
them.
> > Then calls can be made to the plugins on demand. All plugins run within
the
> > same thread. All calls to the plugin are made through a JavaScript
function
> > called "pluginRequest". Because of this, we create a Function object
that
> > points to that pluginRequest function. Then we store this function
object on
> > the ScriptPlugin object along with the scope for this plugin. Whenever a
> > request is made, we get a new context (Context.enter();), call
pluginRequest
> > (passing in the required parameters), and then exit the context.
> >
> > My question: is there a better way to do this?
>
> But how do you evaluate the scripts itself? Do you precompile them
> during plugin initialization?
>
> > Performance has been a little
> > dissappointing and we wonder if we shouldn't be using the Function
object?
>
> You can try to profile your application to see what takes most of the
time.
>
> > Or if we should store the context permamently?
>
> No, the pattern
> cx = Context.enter();
> try { ... } finally { Context.exit(); }
> should always be followed.
>
> Context.enter just create an object and put it inside ThreadLocal while
> Context.exit set that ThreadLocal to null. Evaluation of any script will
> take longer time.
>
> Regards, Igor
>
>
>
>

.