In Moon APNS, what is the logic behind fetching valid tokens, in GetFeedBack method?

Question

I have been trying to figure out list of valid tokens for my Apple app using MoonAPNS library. While using GetFeedBack() the count of received tokens is varying drastically after few minutes. In first attempt it was around 8000. Then it was 0 in third attempt it was 1 & again it was 0.

I am using it with valid production certificate. & Have successfully pushed notifications using same certificate to sampled devices.

I do not understand the logic of the code & on what basis it is providing received tokens. The code downloaded from Moon APNS is as below.

public List<Feedback> GetFeedBack()
{
  try
  {
    var feedbacks = new List<Feedback>();
    Logger.Info("Connecting to feedback service.");

    if (!_conected)
        Connect(_feedbackHost, FeedbackPort, _certificates);

    if (_conected)
    {
        //Set up
        byte[] buffer = new byte[38];
        int recd = 0;
        DateTime minTimestamp = DateTime.Now.AddYears(-1);

        //Get the first feedback
        recd = _apnsStream.Read(buffer, 0, buffer.Length);
        Logger.Info("Feedback response received.");

        if (recd == 0)
            Logger.Info("Feedback response is empty.");

        //Continue while we have results and are not disposing
        while (recd > 0)
        {
            Logger.Info("processing feedback response");
            var fb = new Feedback();

            //Get our seconds since 1970 ?
            byte[] bSeconds = new byte[4];
            byte[] bDeviceToken = new byte[32];

            Array.Copy(buffer, 0, bSeconds, 0, 4);

            //Check endianness
            if (BitConverter.IsLittleEndian)
                Array.Reverse(bSeconds);

            int tSeconds = BitConverter.ToInt32(bSeconds, 0);

            //Add seconds since 1970 to that date, in UTC and then get it locally
            fb.Timestamp = new DateTime(1970, 1, 1, 0, 0, 0, DateTimeKind.Utc).AddSeconds(tSeconds).ToLocalTime();


            //Now copy out the device token
            Array.Copy(buffer, 6, bDeviceToken, 0, 32);

            fb.DeviceToken = BitConverter.ToString(bDeviceToken).Replace("-", "").ToLower().Trim();

            //Make sure we have a good feedback tuple
            if (fb.DeviceToken.Length == 64 && fb.Timestamp > minTimestamp)
            {
                //Raise event
                //this.Feedback(this, fb);
                feedbacks.Add(fb);
            }

            //Clear our array to reuse it
            Array.Clear(buffer, 0, buffer.Length);

            //Read the next feedback
            recd = _apnsStream.Read(buffer, 0, buffer.Length);
        }
        //clode the connection here !
        Disconnect();
        if (feedbacks.Count > 0)
            Logger.Info("Total {0} feedbacks received.", feedbacks.Count);
        return feedbacks;
    }
  }
  catch (Exception ex)
  {
    Logger.Error("Error occurred on receiving feed back. - " + ex.Message);
    return null;
  }
  return null;
}

}

Answer 1

Personally I have not used Moon APNS, but the way the APNS Feedback Service works is every time you call it, it will return inactive tokens since the last time you called the feedback service. And that explains the pattern you are seeing here.