httpbench.go, go version of simplified ab

httpbench.go

package main

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

func main() {
        var (
                numRequests int
                testTime    int
                targetURL   string
                userAgent   string
        )

        flag.IntVar(&numRequests, "n", 1000, "Number of requests")
        flag.IntVar(&testTime, "t", 60, "Duration of test in seconds")
        flag.StringVar(&targetURL, "url", "http://example.com", "Target URL")
        flag.StringVar(&userAgent, "ua", "Mozilla/5.0 (Windows NT 6.2; rv:20.0) Gecko/20121202 Firefox/20.0", "User-Agent header value")
        flag.Parse()

        requestsChan := make(chan struct{}, numRequests)
        var wg sync.WaitGroup
        var totalData int64
        var totalRequests int
        var totalDuration time.Duration

        // Start the timer
        //startTime := time.Now()
        timer := time.NewTimer(time.Duration(testTime) * time.Second)

        for i := 0; i < numRequests; i++ {
                wg.Add(1)
                go func() {
                        defer wg.Done()
                        select {
                        case <-timer.C:
                                return
                        case requestsChan <- struct{}{}:
                                req, err := http.NewRequest("GET", targetURL, nil)
                                if err != nil {
                                        fmt.Printf("Failed to create request: %v\n", err)
                                        return
                                }
                                req.Header.Set("User-Agent", userAgent)

                                startTime := time.Now()
                                resp, err := http.DefaultClient.Do(req)
                                if err != nil {
                                        fmt.Printf("Error making request: %v\n", err)
                                        return
                                }
                                nbytes, err := io.Copy(ioutil.Discard, resp.Body)
                                if err != nil {
                                        fmt.Printf("Error reading response body: %v\n", err)
                                        return
                                }
                                resp.Body.Close()

                                duration := time.Since(startTime)
                                totalDuration += duration
                                totalData += nbytes
                                totalRequests++
                                <-requestsChan
                        }
                }()
        }

        wg.Wait()
        timer.Stop()

        if totalRequests > 0 {
                avgTime := totalDuration / time.Duration(totalRequests)
                fmt.Printf("Total data transferred: %d Mbytes\n", totalData/1024/1024)
                fmt.Printf("Total requests completed: %d\n", totalRequests)
                fmt.Printf("Average time per request: %v\n", avgTime)
        } else {
                fmt.Println("No requests were completed.")
        }
}