[Mobile config] Add v2 endpoints to GatewayInfoV2. Change min_refreshed_at to min_updated_at

[kurotych]

After #902 was implemented, there is now a last_changed_at field, which better fits the purpose compared to refreshed_at, as last_changed_at signals radio changes.

This breaks info_stream_v2 backward compatibility, but it is expected that no clients are using v2 yet.
Related PR: helium/proto#434

UPD: Added appropriate v2 endpoints that returns GatewayInfoV2 which uses v1 request version since nothing (from request side) has changed

[jeffgrunewald]

Suggested change

	let rows: Vec<Vec<u8>> = sqlx::query_scalar(GET_UPDATED_RADIOS)
	.bind(min_updated_at)
	.fetch_all(db)
	.await?;
	let mut radios = HashSet::new();
	for row in rows {
	let entity_key_b: &[u8] = &row;
	let entity_key = bs58::encode(entity_key_b).into_string();
	let pk = PublicKeyBinary::from_str(&entity_key)?;
	radios.insert(pk);
	}
	let radios: HashSet<PublicKeyBinary> = sqlx::query_scalar(GET_UPDATED_RADIOS)
	.bind(min_updated_at)
	.fetch(db)
	.await
	.map(|row| {
	let entity_key_b: &[u8] = &row;
	let entity_key = bs58::encode(entity_key_b).into_string();
	PublicKeyBinary::from_str(&entity_key)
	})
	.collect::<Result<HashSet<PublicKeyBinary>, helium_crypto::Error>>()?;

this probably necessitates importing StreamExt or similar but avoids the extra allocations

[michaeldjeffrey]

helium-crypto-rs provides a sqlx mapping for PublicKeyBinary https://github.com/helium/helium-crypto-rs/blob/main/src/public_key_binary.rs#L115

[kurotych]

Hi @michaeldjeffrey thanks for information. The helium-crypto-rs provides a sqlx mapping for PublicKeyBinary which stored in database as string. In our case pubkey is stored as a bytea type. So when I try to use helium-crypto-rs
mapping like below

Ok(sqlx::query_as::<_, (PublicKeyBinary,)>(GET_UPDATED_RADIOS)
           .bind(min_updated_at)
           .fetch(db)
           .map_ok(|(entity_key,)| entity_key)
           .try_collect::<HashSet<_>>()
           .await?)

I've got an error: mismatched types; Rust type `helium_crypto::public_key_binary::PublicKeyBinary` (as SQL type `text`) is not compatible with SQL type BYTEA

To make it work we need to extend decode function in helium-crypto-rs https://github.com/helium/helium-crypto-rs/blob/main/src/public_key_binary.rs#L150 to make it support bytea. I think this is not in the scope of this PR and I'm not sure that it is worth since I have no information how often we store PublicKeyBinary in bytea type.

[michaeldjeffrey]

No doubt. That's a good @madninja question. Anyways, carry on 👯

[jeffgrunewald]

the original pool variable name made sense here as-is when it was the only database connection this function needed but in general i'd lean more towards the app's "owned" database connection more generically and the one "owned" by an outside service (the metadata db in this case) with more specificity the way we do in the config service's settings or else just give them both more specific names to avoid any confusion

[jeffgrunewald]

Suggested change

	let stream = gateway_info::db::all_info_stream(&pool, &device_types);
	if request.min_updated_at > 0 {
	let min_updated_at = Utc
	.timestamp_opt(request.min_updated_at as i64, 0)
	.single()
	.ok_or(Status::invalid_argument(
	"Invalid min_refreshed_at argument",
	))?;
	let updated_redios = get_updated_radios(&mc_pool, min_updated_at).await?;
	let stream = stream
	.filter(|v| future::ready(updated_redios.contains(&v.address)))
	.boxed();
	stream_multi_gateways_info(stream, tx.clone(), signing_key.clone(), batch_size)
	.await
	} else {
	stream_multi_gateways_info(stream, tx.clone(), signing_key.clone(), batch_size)
	.await
	}
	let stream =
	if request.min_updated_at > 0 {
	let min_updated_at = Utc
	.timestamp_opt(request.min_updated_at as i64, 0)
	.single()
	.ok_or(Status::invalid_argument(
	"Invalid min_refreshed_at argument",
	))?;
	let updated_redios = get_updated_radios(&mc_pool, min_updated_at).await?;
	gateway_info::db::all_info_stream(&pool, &device_types)
	.filter(|v| future::ready(updated_redios.contains(&v.address)))
	.boxed();
	} else {
	gateway_info::db::all_info_stream(&pool, &device_types)
	};
	stream_multi_gateways_info(stream, tx.clone(), signing_key.clone(), batch_size).await

i don't know that this really makes a difference; i wanted to get it down to a single invocation of the stream but i don't think we can fully clean that up unless we added a no-op filter on the branch that doesn't check updated at so feel free to ignore here

[kurotych]

I've tried to do it in a similar way, but I'm facing incompatible types or borrow checker errors.

[kurotych]

PR is converted back to draft
helium/proto#434 (comment)