Amqp source add

[stan-dot]

Fixes #806

My first contribution to the repo, I assume it has a couple of mistakes at this point, so draft for now.

I'd welcome an initial review.

[stan-dot]

looking for help with this error:

error[E0277]: the trait bound `AmqpState: arroyo_types::Data` is not satisfied
   --> crates/arroyo-connectors/src/amqp/operator.rs:163:55
    |
163 | ...                   let s = ctx.table_manager.get_global_keyed_state("k").await
    |                                                 ^^^^^^^^^^^^^^^^^^^^^^ the trait `bincode::Encode` is not implemented for `AmqpState`
    |
    = help: the following other types implement trait `bincode::Encode`:
              &'a CStr
              &'a T
              &std::path::Path
              ()
              (A, B)
              (A, B, C)
              (A, B, C, D)
              (A, B, C, D, E)
            and 141 others
    = note: required for `AmqpState` to implement `arroyo_types::Data`
note: required by a bound in `TableManager::get_global_keyed_state`
   --> /home/runner/work/arroyo/arroyo/crates/arroyo-state/src/tables/table_manager.rs:387:52
    |
387 |     pub async fn get_global_keyed_state<K: Key, V: Data>(
    |                                                    ^^^^ required by this bound in `TableManager::get_global_keyed_state`

[stan-dot]

@ecarrara , @mwylde I saw your commits in the arguably similar standard Rabbit MQ connector (https://github.com/ArroyoSystems/arroyo/blob/master/crates/arroyo-connectors/src/rabbitmq/source.rs), I'm a bit confused about the offsets and GlobalKeyedView, could you please take a quick look?

[mwylde]

@stan-dot — I'm sorry this has taken so long.

There are a few issues here:

The error you posted about the trait bound AmqpState: arroyo_types::Data is not satisfied means that in order for a struct to be stored in state, it needs to satisfy the arroyo_types::Data trait:

arroyo/crates/arroyo-types/src/lib.rs

Line 158 in 760a8a2

pub trait Data: Debug + Clone + Encode + Decode + Send + 'static {}

so it needs to implement all of those traits (Debug + Clone + Encode + Decode + Send), but currently it jus implements Debug and Clone. You can fix this by deriving Encode and Decode (see an example here:

arroyo/crates/arroyo-connectors/src/kafka/source/mod.rs

Lines 47 to 51 in 760a8a2

	#[derive(Copy, Clone, Debug, Encode, Decode, PartialEq, PartialOrd)]
	pub struct KafkaState {
	partition: i32,
	offset: i64,
	}

)

There also appear to be some problems with results and ?. There are various places you're propagating an error with ? in a method that returns lapin::Result but the error you're propagating cannot be converted into a lapin::Error. This will likely work as you expect if you instead use anyhow::Result.

[stan-dot]

thanks for response @mwylde this has been very helpful.

I think I addressed the build errors in operator.rs now I notice I didn't expect the table.json to be necessary to define and then import inside mod.rs.

How to structure mod.rs and how to arrive at the right schemas for profile.json and table.json?