Function downloadSASURLs

tests/random/random.go:138–186

downloadSASURLs downloads the SAS URLs in a group and measures the download speed

(l *zerolog.Logger, group []string)

// downloadSASURLs downloads the SAS URLs in a group and measures the download speed
func downloadSASURLs(l *zerolog.Logger, group []string) ([]float64, int) {
	readsPerBlob := 5
	var wg sync.WaitGroup
	l.Info().Int("groupSize", len(group)).Int("readsPerBlob", readsPerBlob).Strs("urls", group).Msg("downloading blobs")
	speeds := []float64{}
	failures := 0

	speedsChan := make(chan []float64, readsPerBlob)
	failuresChan := make(chan int, readsPerBlob)

	for _, sasURL := range group {
		wg.Add(1)
		go func(sasURL string) {
			defer wg.Done()

			if sasURL == "" {
				l.Warn().Str("url", sasURL).Msg("skipping SAS URL")
				return
			}

			blobSpeeds, f, err := downloadSASURL(l, sasURL, readsPerBlob)
			if err != nil {
				l.Error().Err(err).Str("url", sasURL).Msg("download error")
				failuresChan <- f
			}

			speedsChan <- blobSpeeds
		}(sasURL)
	}

	doneChan := make(chan bool, 1)
	go func() {
		wg.Wait()
		doneChan <- true
	}()

	for {
		select {
		case blobSpeeds := <-speedsChan:
			speeds = append(speeds, blobSpeeds...)

		case failure := <-failuresChan:
			failures += failure

		case <-doneChan:
			return speeds, failures
		}
	}
}

// downloadSASURL downloads a SAS URL and returns the number of bytes downloaded.
func downloadSASURL(l *zerolog.Logger, sasURL string, readsPerBlob int) ([]float64, int, error) {