Method fetchKey

internal/nodes/http_cache_task_manager.go:218–262

TODO 增加失败重试

(key *pb.HTTPCacheTaskKey)

// TODO 增加失败重试
func (this *HTTPCacheTaskManager) fetchKey(key *pb.HTTPCacheTaskKey) error {
	var fullKey = key.Key
	if !this.protocolReg.MatchString(fullKey) {
		fullKey = "https://" + fullKey
	}

	req, err := http.NewRequest(http.MethodGet, fullKey, nil)
	if err != nil {
		return fmt.Errorf("invalid url: '%s': %w", fullKey, err)
	}

	// TODO 可以在管理界面自定义Header
	req.Header.Set("X-Edge-Cache-Action", "fetch")
	req.Header.Set("User-Agent", "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/85.0.4183.121 Safari/537.36") // TODO 可以定义
	req.Header.Set("Accept-Encoding", "gzip, deflate, br")
	resp, err := this.httpClient().Do(req)
	if err != nil {
		err = this.simplifyErr(err)
		return fmt.Errorf("request failed: '%s': %w", fullKey, err)
	}

	defer func() {
		_ = resp.Body.Close()
	}()

	// 处理502
	if resp.StatusCode == http.StatusBadGateway {
		return errors.New("read origin site timeout")
	}

	// 读取内容，以便于生成缓存
	var buf = utils.BytePool16k.Get()
	_, err = io.CopyBuffer(io.Discard, resp.Body, buf.Bytes)
	utils.BytePool16k.Put(buf)
	if err != nil {
		if err != io.EOF {
			err = this.simplifyErr(err)
			return fmt.Errorf("request failed: '%s': %w", fullKey, err)
		} else {
			err = nil
		}
	}

	return nil
}

func (this *HTTPCacheTaskManager) simplifyErr(err error) error {
	if err == nil {