feat: simplify PayloadBuilder setup (#14276)

crates/payload/builder/Cargo.toml

@@ -26,7 +26,6 @@ alloy-primitives = { workspace = true, optional = true }
 alloy-rpc-types = { workspace = true, features = ["engine"] }
 
 # async
-async-trait.workspace = true
 tokio = { workspace = true, features = ["sync"] }
 tokio-stream.workspace = true
 futures-util.workspace = true

crates/payload/builder/src/service.rs

@@ -11,9 +11,7 @@ use alloy_consensus::BlockHeader;
 use alloy_rpc_types::engine::PayloadId;
 use futures_util::{future::FutureExt, Stream, StreamExt};
 use reth_chain_state::CanonStateNotification;
-use reth_payload_builder_primitives::{
-    Events, PayloadBuilder, PayloadBuilderError, PayloadEvents, PayloadStoreExt,
-};
+use reth_payload_builder_primitives::{Events, PayloadBuilderError, PayloadEvents};
 use reth_payload_primitives::{BuiltPayload, PayloadBuilderAttributes, PayloadKind, PayloadTypes};
 use reth_primitives_traits::NodePrimitives;
 use std::{
@@ -38,7 +36,7 @@ type PayloadFuture<P> = Pin<Box<dyn Future<Output = Result<P, PayloadBuilderErro
 /// API).
 #[derive(Debug)]
 pub struct PayloadStore<T: PayloadTypes> {
-    inner: Arc<dyn PayloadStoreExt<T>>,
+    inner: Arc<PayloadBuilderHandle<T>>,
 }
 
 impl<T> PayloadStore<T>
@@ -91,10 +89,7 @@ where
     T: PayloadTypes,
 {
     /// Create a new instance
-    pub fn new<P>(inner: P) -> Self
-    where
-        P: PayloadStoreExt<T> + 'static,
-    {
+    pub fn new(inner: PayloadBuilderHandle<T>) -> Self {
         Self { inner: Arc::new(inner) }
     }
 }
@@ -117,36 +112,40 @@ pub struct PayloadBuilderHandle<T: PayloadTypes> {
     to_service: mpsc::UnboundedSender<PayloadServiceCommand<T>>,
 }
 
-// === impl PayloadBuilderHandle ===
+impl<T: PayloadTypes> PayloadBuilderHandle<T> {
+    /// Creates a new payload builder handle for the given channel.
+    ///
+    /// Note: this is only used internally by the [`PayloadBuilderService`] to manage the payload
+    /// building flow See [`PayloadBuilderService::poll`] for implementation details.
+    pub const fn new(to_service: mpsc::UnboundedSender<PayloadServiceCommand<T>>) -> Self {
+        Self { to_service }
+    }
 
-#[async_trait::async_trait]
-impl<T> PayloadBuilder for PayloadBuilderHandle<T>
-where
-    T: PayloadTypes,
-{
-    type PayloadType = T;
-    type Error = PayloadBuilderError;
-
-    fn send_new_payload(
+    /// Sends a message to the service to start building a new payload for the given payload.
+    ///
+    /// Returns a receiver that will receive the payload id.
+    pub fn send_new_payload(
         &self,
-        attr: <Self::PayloadType as PayloadTypes>::PayloadBuilderAttributes,
-    ) -> Receiver<Result<PayloadId, Self::Error>> {
+        attr: T::PayloadBuilderAttributes,
+    ) -> Receiver<Result<PayloadId, PayloadBuilderError>> {
         let (tx, rx) = oneshot::channel();
         let _ = self.to_service.send(PayloadServiceCommand::BuildNewPayload(attr, tx));
         rx
     }
 
+    /// Returns the best payload for the given identifier.
     /// Note: this does not resolve the job if it's still in progress.
-    async fn best_payload(
+    pub async fn best_payload(
         &self,
         id: PayloadId,
-    ) -> Option<Result<<Self::PayloadType as PayloadTypes>::BuiltPayload, Self::Error>> {
+    ) -> Option<Result<T::BuiltPayload, PayloadBuilderError>> {
         let (tx, rx) = oneshot::channel();
         self.to_service.send(PayloadServiceCommand::BestPayload(id, tx)).ok()?;
         rx.await.ok()?
     }
 
-    async fn resolve_kind(
+    /// Resolves the payload job and returns the best payload that has been built so far.
+    pub async fn resolve_kind(
         &self,
         id: PayloadId,
         kind: PayloadKind,
@@ -159,7 +158,9 @@ where
         }
     }
 
-    async fn subscribe(&self) -> Result<PayloadEvents<Self::PayloadType>, Self::Error> {
+    /// Sends a message to the service to subscribe to payload events.
+    /// Returns a receiver that will receive them.
+    pub async fn subscribe(&self) -> Result<PayloadEvents<T>, PayloadBuilderError> {
         let (tx, rx) = oneshot::channel();
         let _ = self.to_service.send(PayloadServiceCommand::Subscribe(tx));
         Ok(PayloadEvents { receiver: rx.await? })
@@ -168,7 +169,7 @@ where
     /// Returns the payload attributes associated with the given identifier.
     ///
     /// Note: this returns the attributes of the payload and does not resolve the job.
-    async fn payload_attributes(
+    pub async fn payload_attributes(
         &self,
         id: PayloadId,
     ) -> Option<Result<T::PayloadBuilderAttributes, PayloadBuilderError>> {
@@ -178,19 +179,6 @@ where
     }
 }
 
-impl<T> PayloadBuilderHandle<T>
-where
-    T: PayloadTypes,
-{
-    /// Creates a new payload builder handle for the given channel.
-    ///
-    /// Note: this is only used internally by the [`PayloadBuilderService`] to manage the payload
-    /// building flow See [`PayloadBuilderService::poll`] for implementation details.
-    pub const fn new(to_service: mpsc::UnboundedSender<PayloadServiceCommand<T>>) -> Self {
-        Self { to_service }
-    }
-}
-
 impl<T> Clone for PayloadBuilderHandle<T>
 where
     T: PayloadTypes,