feat: add Payload build abstraction (#2143)

crates/rpc/rpc-types/src/eth/engine/forkchoice.rs

@@ -1,5 +1,6 @@
 use super::{PayloadStatus, PayloadStatusEnum};
-use reth_primitives::{H256, H64};
+use crate::engine::PayloadId;
+use reth_primitives::H256;
 use serde::{Deserialize, Serialize};
 
 /// This structure encapsulates the fork choice state
@@ -15,7 +16,7 @@ pub struct ForkchoiceState {
 #[serde(rename_all = "camelCase")]
 pub struct ForkchoiceUpdated {
     pub payload_status: PayloadStatus,
-    pub payload_id: Option<H64>,
+    pub payload_id: Option<PayloadId>,
 }
 
 impl ForkchoiceUpdated {
@@ -32,7 +33,7 @@ impl ForkchoiceUpdated {
         self
     }
 
-    pub fn with_payload_id(mut self, id: H64) -> Self {
+    pub fn with_payload_id(mut self, id: PayloadId) -> Self {
         self.payload_id = Some(id);
         self
     }

crates/rpc/rpc-types/src/eth/engine/payload.rs

@@ -2,11 +2,24 @@ use reth_primitives::{
     constants::MIN_PROTOCOL_BASE_FEE_U256,
     proofs::{self, EMPTY_LIST_HASH},
     Address, Block, Bloom, Bytes, Header, SealedBlock, TransactionSigned, UintTryTo, Withdrawal,
-    H256, U256, U64,
+    H256, H64, U256, U64,
 };
 use reth_rlp::{Decodable, Encodable};
 use serde::{ser::SerializeMap, Deserialize, Serialize, Serializer};
 
+/// And 8-byte identifier for an execution payload.
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Serialize, Deserialize, Hash)]
+pub struct PayloadId(H64);
+
+// === impl PayloadId ===
+
+impl PayloadId {
+    /// Creates a new payload id from the given identifier.
+    pub fn new(id: [u8; 8]) -> Self {
+        Self(H64::from(id))
+    }
+}
+
 /// This structure maps on the ExecutionPayload structure of the beacon chain spec.
 ///
 /// See also: <https://github.com/ethereum/execution-apis/blob/6709c2a795b707202e93c4f2867fa0bf2640a84f/src/engine/paris.md#executionpayloadv1>