Module router

High level API that performs sequence and PID checking as well as ACK validation.

Workflow

• NlRouter::send sends a message and does automatic seq handling.
• A thread in the background receives all messages that sent to the socket in response.
• Each message is sent on the channel match the sequence number to the NlRouterReceiverHandle that corresponds to the request.
• Errors in packet reception and parsing are broadcast to all receivers.
• An NlRouterReceiverHandle can be used as an iterator and will return None either when all messages corresponding to the request have been received or there is a fatal error.

Design decisions

Older users of the library might recognize some of the funtionality in NlRouter as code that previously was associated with NlSocketHandle. The reason for this migration is primarily due to some deficiencies found in the previous implementation. NlSocketHandle relied heavily on a .send()/.recv() workflow. This meant that, while it was designed to address ACK handling and receiving all responses associated with a given request, the implementation actually was unable to handle two separate responses corresponding to two seaparate requests interleaved with each other. Effectively, this meant that the socket handle had no awareness of multiple requests being sent before all data was read from the socket and would result in parsing errors if used in this way.

NlRouter aims to address this by associating all messages received by the socket with a request or multicast group so that messages can be interleaved and still processed in the correct order by the handle associated with the request that generated it.

Features

The async feature exposed by cargo allows the socket to use Rust’s tokio for async IO.

Modules

synchronous

Synchronous packet routing functionality.