perf(rpc): optimize block_cfg (#100)

* perf(rpc): optimize block_cfg

We were unnecessarily loading a whole block for getting the block cfg, when we only need the header. This means that any calls that use block_cfg were much more expensive than needed.

* v bump

Author: Evalir

Cargo.toml

@@ -3,7 +3,7 @@ members = ["crates/*"]
 resolver = "2"
 
 [workspace.package]
-version = "0.8.2"
+version = "0.8.3"
 edition = "2021"
 rust-version = "1.81"
 authors = ["init4"]

crates/rpc/src/ctx.rs

@@ -312,6 +312,20 @@ where
         Ok(builder.build())
     }
 
+    /// Get the [`Header`] for a given block.
+    pub async fn raw_header(
+        &self,
+        t: impl Into<BlockId>,
+    ) -> Result<Option<(B256, Header)>, EthApiError> {
+        let Some(hash) = self.provider.block_hash_for_id(t.into())? else {
+            return Ok(None);
+        };
+
+        let header = self.cache.get_header(hash).await.map_err(EthApiError::from)?;
+
+        Ok(Some((hash, header)))
+    }
+
     /// Get the block for a given block, returning the block hash and
     /// the block itself.
     pub async fn raw_block(
@@ -513,20 +527,18 @@ where
         build_signet_receipt(tx, meta, receipt, all_receipts.to_vec()).map(Some)
     }
 
-    /// Create the [`Block`] object for a specific [`BlockId`].
+    /// Create the [`Header`] object for a specific [`BlockId`].
     pub async fn block_cfg(&self, mut block_id: BlockId) -> Result<Header, EthApiError> {
         // If the block is pending, we'll load the latest and
         let pending = block_id.is_pending();
         if pending {
             block_id = BlockId::latest();
         }
 
-        let Some((_, block)) = self.raw_block(block_id).await? else {
+        let Some((_, mut header)) = self.raw_header(block_id).await? else {
             return Err(EthApiError::HeaderNotFound(block_id));
         };
 
-        let mut header = block.clone_header();
-
         // Modify the header for pending blocks, to simulate the next block.
         if pending {
             header.parent_hash = header.hash_slow();