parse.go

package main

import (
	"encoding/json"
	"io/ioutil"
	"os"
)

type Event struct {
	Children []Child
	EndTime  float64
}

type Child struct {
	Data ChildData
	Type string
}

type ChildData struct {
	RequestId  string
	Url        string
	StatusCode int
}

func main() {
	file := readFile()
	getEvents(file)
}

func readFile() []byte {
	args := os.Args
	file, err := ioutil.ReadFile(args[1])
	if err != nil {
		panic(err)
	}
	return file
}

func getEvents(file []byte) []Event {
	events := make([]Event, 1)
	err := json.Unmarshal(file, &events)
	if err != nil {
		panic(err)
	}
	return events
}

results.sh

$ time ./parse data.json
./parse data.json  4.54s user 0.14s system 99% cpu 4.690 total