Trait SubscriptionCoordinator

pub trait SubscriptionCoordinator<'a, CtxT, S>
where
    S: ScalarValue,
{
    type Connection: SubscriptionConnection<S>;
    type Error;

    // Required method
    fn subscribe(
        &'a self,
        _: &'a GraphQLRequest<S>,
        _: &'a CtxT,
    ) -> BoxFuture<'a, Result<Self::Connection, Self::Error>>;
}

Global subscription coordinator trait.

With regular queries we could get away with not having some in-between layer, but for subscriptions it is needed, otherwise the integration crates can become really messy and cumbersome to maintain. Subscriptions are also quite a bit more stability sensitive than regular queries, they provide a great vector for DOS attacks and can bring down a server easily if not handled right.

This trait implementation might include the following features:

• contains the schema
• keeps track of subscription connections
• handles subscription start, maintains a global subscription id
• max subscription limits / concurrency limits
• subscription de-duplication
• reconnection on connection loss / buffering / re-synchronisation

'a is how long spawned connections live for.

Required Associated Types

type Connection: SubscriptionConnection<S>

Type of SubscriptionConnections this SubscriptionCoordinator returns

type Error

Type of error while trying to spawn SubscriptionConnection

Required Methods

fn subscribe( &'a self, _: &'a GraphQLRequest<S>, _: &'a CtxT, ) -> BoxFuture<'a, Result<Self::Connection, Self::Error>>

Return SubscriptionConnection based on given GraphQLRequest

Implementors