Is there a way to profile Javascript executed with Rhino?

[jonbartels]

I am a user of Mirth Connect which uses Rhino to run Javascript. I had a use case the other day where my team needed to profile a dozen lines of Javascript. We accomplished this by simply adding logger statements before and after each line of code to capture timing data.

Is there a better way to profile JS when running from Rhino? I did some searching and was able to find benchmarking code and discussion of profiling various JS engines.

[p-bakker]

To my knowledge there isn't a stand-alone profiler implementation for Rhino, neither is there a standard for generic Profiler implementations (similar to the Debug Adapter Protocol for debugging) that allows you to plugin a runtime like Rhino into an IDE and be able to profile a runtime using a standardized Profiling UI.

So, if you want a proper profiler, I think you'd have to create one yourself.

The basic structure of an implementation would be something like: implement the org.mozilla.javascript.debug.Debugger interface and register it as debugger on your context using Context cx.setDebugger(...);

In your org.mozilla.javascript.debug.Debugger.getFrame() implementation you can then record whatever you want to record

Of course there are many more details to it, but that is the basic gist of it

[rPraml]

I've used JProfiler, that will show up compiled javascript classes. With some effort, you may find out where your performance bottleneck is.
Note: JProfiler has a default exclusion filter for "org.mozilla.*" - which has to be disabled.