From b710e57f9ade775cc27e8983f3cfc092c62a2853 Mon Sep 17 00:00:00 2001
From: Matthias Seitz <matthias.seitz@outlook.de>
Date: Mon, 21 Aug 2023 14:10:15 +0200
Subject: [PATCH] feat: add load_trusted_setup_from_bytes (#4290)

---
 crates/primitives/src/constants/eip4844.rs | 44 +++++++++++++++++++---
 1 file changed, 38 insertions(+), 6 deletions(-)

diff --git a/crates/primitives/src/constants/eip4844.rs b/crates/primitives/src/constants/eip4844.rs
index 602229d2cc..69f6cbce76 100644
--- a/crates/primitives/src/constants/eip4844.rs
+++ b/crates/primitives/src/constants/eip4844.rs
@@ -28,15 +28,47 @@ pub const TARGET_BLOBS_PER_BLOCK: u64 = TARGET_DATA_GAS_PER_BLOCK / DATA_GAS_PER
 /// Used to determine the price for next data blob
 pub const BLOB_GASPRICE_UPDATE_FRACTION: u64 = 3_338_477u64; // 3338477
 
+/// Commitment version of a KZG commitment
+pub const VERSIONED_HASH_VERSION_KZG: u8 = 0x01;
+
 /// KZG Trusted setup raw
-const TRUSTED_SETUP_RAW: &str = include_str!("../../res/eip4844/trusted_setup.txt");
+const TRUSTED_SETUP_RAW: &[u8] = include_bytes!("../../res/eip4844/trusted_setup.txt");
 
 /// KZG trusted setup
 pub static KZG_TRUSTED_SETUP: Lazy<Arc<KzgSettings>> = Lazy::new(|| {
-    let mut file = tempfile::NamedTempFile::new().unwrap();
-    file.write_all(TRUSTED_SETUP_RAW.as_bytes()).unwrap();
-    Arc::new(KzgSettings::load_trusted_setup_file(file.path().into()).unwrap())
+    Arc::new(
+        load_trusted_setup_from_bytes(TRUSTED_SETUP_RAW).expect("Failed to load trusted setup"),
+    )
 });
 
-/// Commitment version of a KZG commitment
-pub const VERSIONED_HASH_VERSION_KZG: u8 = 0x01;
+/// Loads the trusted setup parameters from the given bytes and returns the [KzgSettings].
+///
+/// This creates a temp file to store the bytes and then loads the [KzgSettings] from the file via
+/// [KzgSettings::load_trusted_setup_file].
+pub fn load_trusted_setup_from_bytes(bytes: &[u8]) -> Result<KzgSettings, LoadKzgSettingsError> {
+    let mut file = tempfile::NamedTempFile::new().map_err(LoadKzgSettingsError::TempFileErr)?;
+    file.write_all(bytes).map_err(LoadKzgSettingsError::TempFileErr)?;
+    KzgSettings::load_trusted_setup_file(file.path().into()).map_err(LoadKzgSettingsError::KzgError)
+}
+
+/// Error type for loading the trusted setup.
+#[derive(Debug, thiserror::Error)]
+pub enum LoadKzgSettingsError {
+    /// Failed to create temp file to store bytes for loading [KzgSettings] via
+    /// [KzgSettings::load_trusted_setup_file].
+    #[error("Failed to setup temp file: {0:?}")]
+    TempFileErr(#[from] std::io::Error),
+    /// Kzg error
+    #[error("Kzg error: {0:?}")]
+    KzgError(c_kzg::Error),
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn ensure_load_kzg_settings() {
+        let _settings = Arc::clone(&KZG_TRUSTED_SETUP);
+    }
+}