From 7fca8ceb3fe0809fd5583f8e203001332e7d4f24 Mon Sep 17 00:00:00 2001
From: Matthias Seitz <matthias.seitz@outlook.de>
Date: Tue, 7 Jan 2025 21:21:05 +0100
Subject: [PATCH] feat: add standalone rayon recovery functions (#13710)

---
 crates/primitives-traits/src/block/body.rs    | 21 +-----
 crates/primitives-traits/src/lib.rs           |  1 +
 .../primitives-traits/src/transaction/mod.rs  |  1 +
 .../src/transaction/recover.rs                | 68 +++++++++++++++++++
 4 files changed, 72 insertions(+), 19 deletions(-)
 create mode 100644 crates/primitives-traits/src/transaction/recover.rs

diff --git a/crates/primitives-traits/src/block/body.rs b/crates/primitives-traits/src/block/body.rs
index 58fe3c4b43..279e7d45cc 100644
--- a/crates/primitives-traits/src/block/body.rs
+++ b/crates/primitives-traits/src/block/body.rs
@@ -13,9 +13,6 @@ pub trait FullBlockBody: BlockBody<Transaction: FullSignedTx> + MaybeSerdeBincod
 
 impl<T> FullBlockBody for T where T: BlockBody<Transaction: FullSignedTx> + MaybeSerdeBincodeCompat {}
 
-#[cfg(feature = "rayon")]
-use rayon::prelude::*;
-
 /// Abstraction for block's body.
 pub trait BlockBody:
     Send
@@ -115,14 +112,7 @@ pub trait BlockBody:
     where
         Self::Transaction: SignedTransaction,
     {
-        #[cfg(feature = "rayon")]
-        {
-            self.transactions().into_par_iter().map(|tx| tx.recover_signer()).collect()
-        }
-        #[cfg(not(feature = "rayon"))]
-        {
-            self.transactions().iter().map(|tx| tx.recover_signer()).collect()
-        }
+        crate::transaction::recover::recover_signers(self.transactions())
     }
 
     /// Recover signer addresses for all transactions in the block body _without ensuring that the
@@ -133,14 +123,7 @@ pub trait BlockBody:
     where
         Self::Transaction: SignedTransaction,
     {
-        #[cfg(feature = "rayon")]
-        {
-            self.transactions().into_par_iter().map(|tx| tx.recover_signer_unchecked()).collect()
-        }
-        #[cfg(not(feature = "rayon"))]
-        {
-            self.transactions().iter().map(|tx| tx.recover_signer_unchecked()).collect()
-        }
+        crate::transaction::recover::recover_signers_unchecked(self.transactions())
     }
 }
 
diff --git a/crates/primitives-traits/src/lib.rs b/crates/primitives-traits/src/lib.rs
index 322ed33eda..c5d9b710c1 100644
--- a/crates/primitives-traits/src/lib.rs
+++ b/crates/primitives-traits/src/lib.rs
@@ -16,6 +16,7 @@
 //! - `serde`: Adds serde support for all types.
 //! - `secp256k1`: Adds secp256k1 support for transaction signing/recovery. (By default the no-std
 //!   friendly `k256` is used)
+//! - `rayon`: Uses `rayon` for parallel transaction sender recovery in [`BlockBody`] by default.
 
 #![doc(
     html_logo_url = "https://raw.githubusercontent.com/paradigmxyz/reth/main/assets/reth-docs.png",
diff --git a/crates/primitives-traits/src/transaction/mod.rs b/crates/primitives-traits/src/transaction/mod.rs
index 15b3df7fdb..43fe7899d9 100644
--- a/crates/primitives-traits/src/transaction/mod.rs
+++ b/crates/primitives-traits/src/transaction/mod.rs
@@ -5,6 +5,7 @@ pub mod signature;
 pub mod signed;
 
 pub mod error;
+pub mod recover;
 
 pub use alloy_consensus::transaction::{TransactionInfo, TransactionMeta};
 
diff --git a/crates/primitives-traits/src/transaction/recover.rs b/crates/primitives-traits/src/transaction/recover.rs
new file mode 100644
index 0000000000..cad57bc266
--- /dev/null
+++ b/crates/primitives-traits/src/transaction/recover.rs
@@ -0,0 +1,68 @@
+//! Helpers for recovering signers from a set of transactions
+
+#[cfg(feature = "rayon")]
+pub use rayon::*;
+
+#[cfg(not(feature = "rayon"))]
+pub use iter::*;
+
+#[cfg(feature = "rayon")]
+mod rayon {
+    use crate::SignedTransaction;
+    use alloc::vec::Vec;
+    use alloy_primitives::Address;
+    use rayon::prelude::{IntoParallelIterator, ParallelIterator};
+
+    /// Recovers a list of signers from a transaction list iterator.
+    ///
+    /// Returns `None`, if some transaction's signature is invalid
+    pub fn recover_signers<'a, I, T>(txes: I) -> Option<Vec<Address>>
+    where
+        T: SignedTransaction,
+        I: IntoParallelIterator<Item = &'a T> + IntoIterator<Item = &'a T> + Send,
+    {
+        txes.into_par_iter().map(|tx| tx.recover_signer()).collect()
+    }
+
+    /// Recovers a list of signers from a transaction list iterator _without ensuring that the
+    /// signature has a low `s` value_.
+    ///
+    /// Returns `None`, if some transaction's signature is invalid.
+    pub fn recover_signers_unchecked<'a, I, T>(txes: I) -> Option<Vec<Address>>
+    where
+        T: SignedTransaction,
+        I: IntoParallelIterator<Item = &'a T> + IntoIterator<Item = &'a T> + Send,
+    {
+        txes.into_par_iter().map(|tx| tx.recover_signer_unchecked()).collect()
+    }
+}
+
+#[cfg(not(feature = "rayon"))]
+mod iter {
+    use crate::SignedTransaction;
+    use alloc::vec::Vec;
+    use alloy_primitives::Address;
+
+    /// Recovers a list of signers from a transaction list iterator.
+    ///
+    /// Returns `None`, if some transaction's signature is invalid
+    pub fn recover_signers<'a, I, T>(txes: I) -> Option<Vec<Address>>
+    where
+        T: SignedTransaction,
+        I: IntoIterator<Item = &'a T> + IntoIterator<Item = &'a T>,
+    {
+        txes.into_iter().map(|tx| tx.recover_signer()).collect()
+    }
+
+    /// Recovers a list of signers from a transaction list iterator _without ensuring that the
+    /// signature has a low `s` value_.
+    ///
+    /// Returns `None`, if some transaction's signature is invalid.
+    pub fn recover_signers_unchecked<'a, I, T>(txes: I) -> Option<Vec<Address>>
+    where
+        T: SignedTransaction,
+        I: IntoIterator<Item = &'a T> + IntoIterator<Item = &'a T>,
+    {
+        txes.into_iter().map(|tx| tx.recover_signer_unchecked()).collect()
+    }
+}