Performance; calling go function

[michal-laskowski]

I have simple code that gets strings.Builder and writes some strings in a loop. This code takes like ~20000 ns/op (equivalent in Go takes like ~500 ns/op).

Building the string itself, without calling strings.Builder, takes ~8000 ns/op.

Is there any way to optimize Go function calls (on passed objects)?

package goja_test

import (
	"fmt"
	"strings"
	"testing"

	"github.com/dop251/goja"
)

var compiled *goja.Program

func _goja_forIssue() any {
	SCRIPT := `
        function WriteSomething({ sb }) {
            for (let i = 0; i <= 10; i++) {
                const x = 'nnn' + i + ','
                sb.WriteString(x)
            }
        }`
	vm := goja.New()
	if compiled == nil {
		compiled, _ = goja.Compile("perf", SCRIPT, true)
	}
	vm.RunProgram(compiled)
	writeSomething, ok := goja.AssertFunction(vm.Get("WriteSomething"))
	if !ok {
		panic("Not a function")
	}
	sb := &strings.Builder{}
	prms := map[string]any{
		"sb": sb,
	}

	writeSomething(goja.Undefined(), vm.ToValue(prms))

	return sb.String()
}

func BenchmarkSimple1(b *testing.B) {
	for i := 0; i < b.N; i++ {

		_goja_forIssue()
	}

}