Google Nearby connections - Not able to transfer large bytes between 2 devices

Question

When I try to send an object with multiple images(converted to string using Base64) as STREAM type, from the onPayloadTransferUpdate() method, I can see "Failure" result and the devices(tested only when 2 devices are connected) automatically disconnect after that. Is Google Nearby connections not the right option to send large bytes?

Answer 1

Nearby Connections should be able to handle that. There's no explicit size limit on STREAM payloads.

I would suggest chunking the bytes (eg. send a couple KB at a time) and seeing if that helps. You can get into weird situations when you send entire files at once because it loads the bytes into memory twice (once inside your app, and once inside the Nearby process) which can cause out of memory errors. Binder, the interprocess communication layer on Android, also has a limited buffer to send data between processes.

You can also save it as a temporary file and send it as a FILE payload, in which case we will handle the chunking for you.

Disclaimer: I work on Nearby Connections.

Answer 2

1) You don't need to Base64-encode the data for the sake of Nearby Connections -- your STREAM can have raw binary data, and that'll work just fine.

2) How big is this data you're sending, and at what byte offset (you can see this in the PayloadTransferUpdate you get with Status.ERROR) does it fail at? It sounds like your devices are just getting disconnected.

3) What Strategy are you using?

4) If you still have discovery ongoing (i.e. you haven't called stopDiscovery()), try stopping that and then sending your Payload -- discovery is a heavyweight operation that can make it hard to reliably maintain connections between devices for long intervals.