Function attempt

tools/utils/http-helpers.js:455–496

(triesRemaining = maxAttempts, startAt = 0)

    const outputStream = new ConcatStream();

    function attempt(triesRemaining = maxAttempts, startAt = 0) {
      if (startAt > 0) {
        options.headers = {
          ...options.headers,
          Range: `bytes=${startAt}-`
        };
      }

      if (masterProgress &&
          masterProgress.addChildTask) {
        options.progress = masterProgress.addChildTask({
          title: masterProgress.title
        });
      }

      try {
        return Promise.resolve(httpHelpers.request({
          outputStream,
          ...options,
        }));

      } catch (e) {
        const size = outputStream.size;
        const useTry = size === startAt;
        const change = size - startAt;

        if (!useTry || triesRemaining > 0) {
          if (useTry) {
            Console.debug(`Request failed, ${triesRemaining - 1} attempts left`);
          } else {
            Console.debug(`Request failed after ${change} bytes, retrying`);
          }

          return new Promise(
            resolve => setTimeout(resolve, retryDelaySecs * 1000)
          ).then(() => attempt(triesRemaining - (useTry ? 1 : 0), size));
        }

        Console.debug(`Request failed ${maxAttempts} times: failing`);
        return Promise.reject(new files.OfflineError(e));
      }
    }

    const result = attempt().await();
    const response = result.response