optimised_http.go

package main

import (
	"crypto/tls"
	"flag"
	"fmt"
	"io"
	"io/ioutil"
	"net/http"
	"os"
	"strings"
	"time"
)

var (
	FURL = flag.String(
		"url",
		"https://52.167.219.168",
		"Destination URL, supported schemes: http, https. Example: https://gitlab.com",
	)
	FT = flag.Int(
		"time",
		300,
		"Period of time, in seconds. Example: 300",
	)
)

func testRequests(client *http.Client, requests int, discard bool) {
	for requests > 0 {
		requests--
		started := time.Now()

		resp, err := client.Get(*FURL)
		if err != nil {
			fmt.Printf("Could not get data from URL %s: %s\n", *FURL, err.Error())
			continue
		}
		if discard {
			io.Copy(ioutil.Discard, resp.Body)
		}
		resp.Body.Close()

		fmt.Printf(
			"Response time is %.3f seconds\n",
			float32(time.Since(started)/time.Millisecond)/1000,
		)
	}
}

func main() {
	flag.Parse()

	if !strings.HasPrefix(*FURL, "https://") && !strings.HasPrefix(*FURL, "http://") {
		fmt.Println("URL must have one of the prefixes 'https://' or 'http://'.")
		os.Exit(-1)
	}

	if *FT <= 0 {
		fmt.Println("Preiod of time must be grather than zero.")
		os.Exit(-1)
	}

	fmt.Printf("Calculating response time from %s during %d seconds...\n", *FURL, *FT)

	tr := &http.Transport{
		MaxIdleConns:       10,
		IdleConnTimeout:    30 * time.Second,
		DisableCompression: true,
		TLSClientConfig: &tls.Config{
			InsecureSkipVerify: true,
		},
	}
	client := &http.Client{
		Transport: tr,
	}

	fmt.Println()
	fmt.Println("No resumption")
	testRequests(client, 5, false)

	tr = &http.Transport{
		MaxIdleConns:       10,
		IdleConnTimeout:    30 * time.Second,
		DisableCompression: true,
		TLSClientConfig: &tls.Config{
			InsecureSkipVerify: true,
			ClientSessionCache: tls.NewLRUClientSessionCache(1000),
		},
	}
	client = &http.Client{
		Transport: tr,
	}

	fmt.Println()
	fmt.Println("With resumption")
	testRequests(client, 5, false)

	tr = &http.Transport{
		MaxIdleConns:       10,
		IdleConnTimeout:    30 * time.Second,
		DisableCompression: true,
		TLSClientConfig: &tls.Config{
			InsecureSkipVerify:     true,
		},
	}
	client = &http.Client{
		Transport: tr,
	}

	fmt.Println()
	fmt.Println("With keep-alive")
	testRequests(client, 5, true)
}