From b283c74c8f3e9f4c044df71505b2538f5458eef8 Mon Sep 17 00:00:00 2001
From: Arsenii Kulikov <klkvrr@gmail.com>
Date: Fri, 1 Nov 2024 00:02:26 +0400
Subject: [PATCH] sidecar

---
 crates/rpc-types-engine/src/lib.rs     |  2 +
 crates/rpc-types-engine/src/prague.rs  | 63 ++++++++++++++++++++++++++
 crates/rpc-types-engine/src/sidecar.rs | 28 ++++++++----
 3 files changed, 85 insertions(+), 8 deletions(-)
 create mode 100644 crates/rpc-types-engine/src/prague.rs

diff --git a/crates/rpc-types-engine/src/lib.rs b/crates/rpc-types-engine/src/lib.rs
index d91f05b69793..fcc63e4b1206 100644
--- a/crates/rpc-types-engine/src/lib.rs
+++ b/crates/rpc-types-engine/src/lib.rs
@@ -13,6 +13,8 @@ extern crate alloc;
 
 mod cancun;
 pub use cancun::*;
+mod prague;
+pub use prague::*;
 mod sidecar;
 pub use sidecar::*;
 
diff --git a/crates/rpc-types-engine/src/prague.rs b/crates/rpc-types-engine/src/prague.rs
new file mode 100644
index 000000000000..7d5b36d8dad6
--- /dev/null
+++ b/crates/rpc-types-engine/src/prague.rs
@@ -0,0 +1,63 @@
+//! Contains types related to the Prague hardfork that will be used by RPC to communicate with the
+//! beacon consensus engine.
+
+use alloy_eips::eip7685::Requests;
+
+/// Fields introduced in `engine_newPayloadV4` that are not present in the `ExecutionPayload` RPC
+/// object.
+#[derive(Clone, Debug, Default, PartialEq, Eq, Hash)]
+#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
+pub struct PraguePayloadFields {
+    /// EIP-7685 requests.
+    pub requests: Requests,
+    /// Target number of blobs in the block.
+    pub target_blobs_per_block: u64,
+}
+
+/// A container type for [PraguePayloadFields] that may or may not be present.
+#[derive(Clone, Debug, Default, PartialEq, Eq, Hash)]
+#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
+pub struct MaybePraguePayloadFields {
+    fields: Option<PraguePayloadFields>,
+}
+
+impl MaybePraguePayloadFields {
+    /// Returns a new [`MaybePraguePayloadFields`] with no prague fields.
+    pub const fn none() -> Self {
+        Self { fields: None }
+    }
+
+    /// Returns a new [`MaybePraguePayloadFields`] with the given prague fields.
+    pub fn into_inner(self) -> Option<PraguePayloadFields> {
+        self.fields
+    }
+
+    /// Returns the requests, if any.
+    pub fn requests(&self) -> Option<&Requests> {
+        self.fields.as_ref().map(|fields| &fields.requests)
+    }
+
+    /// Returns the target blobs per block, if any.
+    pub fn target_blobs_per_block(&self) -> Option<u64> {
+        self.fields.as_ref().map(|fields| fields.target_blobs_per_block)
+    }
+
+    /// Returns a reference to the inner fields.
+    pub const fn as_ref(&self) -> Option<&PraguePayloadFields> {
+        self.fields.as_ref()
+    }
+}
+
+impl From<PraguePayloadFields> for MaybePraguePayloadFields {
+    #[inline]
+    fn from(fields: PraguePayloadFields) -> Self {
+        Self { fields: Some(fields) }
+    }
+}
+
+impl From<Option<PraguePayloadFields>> for MaybePraguePayloadFields {
+    #[inline]
+    fn from(fields: Option<PraguePayloadFields>) -> Self {
+        Self { fields }
+    }
+}
diff --git a/crates/rpc-types-engine/src/sidecar.rs b/crates/rpc-types-engine/src/sidecar.rs
index a640508bcd8c..267f92bf5462 100644
--- a/crates/rpc-types-engine/src/sidecar.rs
+++ b/crates/rpc-types-engine/src/sidecar.rs
@@ -1,6 +1,8 @@
 //! Contains helpers for dealing with additional parameters of `newPayload` requests.
 
-use crate::{CancunPayloadFields, MaybeCancunPayloadFields};
+use crate::{
+    CancunPayloadFields, MaybeCancunPayloadFields, MaybePraguePayloadFields, PraguePayloadFields,
+};
 use alloc::vec::Vec;
 use alloy_eips::eip7685::Requests;
 use alloy_primitives::B256;
@@ -15,23 +17,23 @@ pub struct ExecutionPayloadSidecar {
     cancun: MaybeCancunPayloadFields,
     /// The EIP-7685 requests provided as additional request params to `engine_newPayloadV4` that
     /// are not present in the `ExecutionPayload`.
-    prague: Option<Requests>,
+    prague: MaybePraguePayloadFields,
 }
 
 impl ExecutionPayloadSidecar {
     /// Returns a new empty instance (pre-cancun, v1, v2)
     pub const fn none() -> Self {
-        Self { cancun: MaybeCancunPayloadFields::none(), prague: None }
+        Self { cancun: MaybeCancunPayloadFields::none(), prague: MaybePraguePayloadFields::none() }
     }
 
     /// Creates a new instance for cancun with the cancun fields for `engine_newPayloadV3`
     pub fn v3(cancun: CancunPayloadFields) -> Self {
-        Self { cancun: cancun.into(), prague: None }
+        Self { cancun: cancun.into(), prague: MaybePraguePayloadFields::none() }
     }
 
     /// Creates a new instance post prague for `engine_newPayloadV4`
-    pub fn v4(cancun: CancunPayloadFields, requests: Requests) -> Self {
-        Self { cancun: cancun.into(), prague: Some(requests) }
+    pub fn v4(cancun: CancunPayloadFields, prague: PraguePayloadFields) -> Self {
+        Self { cancun: cancun.into(), prague: prague.into() }
     }
 
     /// Returns a reference to the [`CancunPayloadFields`].
@@ -39,6 +41,11 @@ impl ExecutionPayloadSidecar {
         self.cancun.as_ref()
     }
 
+    /// Returns a reference to the [`PraguePayloadFields`].
+    pub const fn prague(&self) -> Option<&PraguePayloadFields> {
+        self.prague.as_ref()
+    }
+
     /// Returns the parent beacon block root, if any.
     pub fn parent_beacon_block_root(&self) -> Option<B256> {
         self.cancun.parent_beacon_block_root()
@@ -50,7 +57,12 @@ impl ExecutionPayloadSidecar {
     }
 
     /// Returns the EIP-7685 requests
-    pub const fn requests(&self) -> Option<&Requests> {
-        self.prague.as_ref()
+    pub fn requests(&self) -> Option<&Requests> {
+        self.prague.requests()
+    }
+
+    /// Returns the target blobs per block
+    pub fn target_blobs_per_block(&self) -> Option<u64> {
+        self.prague.target_blobs_per_block()
     }
 }