20,741
edits
Improved J661 support: Difference between revisions
Jump to navigation
Jump to search
m
→Requirements
m (→Requirements) |
|||
| Line 8: | Line 8: | ||
* i.e. avoid polling | * i.e. avoid polling | ||
* provide some form of push/pull support | * provide some form of push/pull support | ||
= Ideas = | |||
* One thing that would be great would maybe to be able to have more than one parameter to the output for the client in one telnet output (for example all the properties that have been requested), but even without that, performance should be far better than with polling I think. | |||
* For your information, in the ARINC 661 protocol, the User Application concatenates several "commands" in the same buffer, denoting each specific command by its ID (and in the case of ARINC, also it's widget ID, but it's not relevant to our problem). In our User Application implementation (which happens to be coded in C++), a lot of parameters which are considered as cyclic are send regardless of their value change, because they change often. However the Server checks for their change, and in this case, it does not go further than their decoding. It turned out that the time the Server takes to decode a huge buffer and make its checks is negligible (of the order of 1 ms for example). | |||
* However I need to check the number of parameters which should be sent to the Client in real scenarios. I don't think it's a lot, because ther is further logic in the Client itself, and it could be possible for the Client to unsubscribe for example when a display format is not presented anymore. | |||
* I was also thinking of supporting several parameters (and even return values) at once, my suggestion would be to still consider hex-encoding the UINT hash and then pre-pend it to each property value, the values could then be separated using a normal comma, so that we end up with a list of CSVs. | |||
* In addition, it might be worthwhile to consider pre-pending a UNIX timestamp to each server-side response, so that clients get some timing information, I guess? | |||
* The list of CSVs sounds good to me. And I agree that having the timestamps could be useful in some usecases. | |||
* supporting multiple values in one response (i.e. like CSV) will inevitably require server-side escaping and client-side "unescaping" of properties. | |||
= Patch prototype = | = Patch prototype = | ||