go_getpages/main.go

package main

import (
	"fmt"
	"io/ioutil"
	"net/http"
	"time"
)

type Data struct {
	length   int
	duration time.Duration
}

func getPage(url string) (Data, error) {

	var d Data

	resp, err := http.Get(url)
	if err != nil {
		return d, err
	}

	defer resp.Body.Close()
	start := time.Now()
	body, err := ioutil.ReadAll(resp.Body)
	if err != nil {
		return d, err
	}
	dur := time.Since(start)

	d.length = len(body)
	d.duration = dur

	return d, nil
}

func main() {
	sites := map[string]string{
		"Google": "http://google.com",
		"Yahoo":  "http://yahoo.com",
		"Bing":   "http://bing.com",
	}

	start := time.Now()

	for name, url := range sites {
		data, err := getPage(url)
		if err != nil {
			fmt.Printf("%s	%s\n", name, err)
		}
		fmt.Printf("%-10s %6.2f KB %7.2f ms\n",
			name,
			float32(data.length)/1024,
			float32(data.duration)/1000000)
	}

	fmt.Printf("Total time: %.3f seconds\n", time.Since(start).Seconds())
}