func copyFromURL()

in internal/version/version.go [308:346]

37 lines of code
8 McCabe index (conditional complexity)


func copyFromURL(dstFile, srcURL string) (err error) {
	f, err := os.Create(dstFile)
	if err != nil {
		return err
	}
	defer func() {
		if err != nil {
			f.Close()
			os.Remove(dstFile)
		}
	}()
	c := &http.Client{
		Transport: &userAgentTransport{&http.Transport{
			// It's already compressed. Prefer accurate ContentLength.
			// (Not that GCS would try to compress it, though)
			DisableCompression: true,
			DisableKeepAlives:  true,
			Proxy:              http.ProxyFromEnvironment,
		}},
	}
	res, err := c.Get(srcURL)
	if err != nil {
		return err
	}
	defer res.Body.Close()
	if res.StatusCode != http.StatusOK {
		return errors.New(res.Status)
	}
	pw := &progressWriter{w: f, total: res.ContentLength}
	n, err := io.Copy(pw, res.Body)
	if err != nil {
		return err
	}
	if res.ContentLength != -1 && res.ContentLength != n {
		return fmt.Errorf("copied %v bytes; expected %v", n, res.ContentLength)
	}
	pw.update() // 100%
	return f.Close()
}