#23773 added a JS tracer which uses Goja as its engine. In this PR I remove the previous tracer which used duktape as well as remove the dependencies.
This PR also comes with 2 fixes in the Goja tracer and one small behavioural change:
I had handled errors in the native Go functions by panicing. My oversight was that Goja only handles panics with a Goja.Value as argument. The difference is panic(goja.Value) allows JS to catch the exception whereas Interrupt(error) doesn't.
There was a race in how I handled Stop.
Because of 1. some of the methods that simply return nil on error (like memory.slice) now throw an exception.
This adds a JS tracer runtime environment based on the Goja VM. The new
runtime replaces the duktape runtime, which will be removed soon.
Goja is implemented in Go and is faster for cases where the Go <-> JS
transition overhead dominates overall performance. It is faster because
duktape is written in C, and the transition cost includes the cost of using
cgo. Another reason for using Goja is that go-duktape is not maintained
anymore.
We expect the performace of JS tracing to be at least as good or better with
this change.
Sina Mahmoodi
Håvard Anda Estensen
Martin Holst Swende