fix(builder): desired block gas limit (#13351)

crates/ethereum/consensus/src/lib.rs

@@ -22,12 +22,12 @@ use reth_consensus_common::validation::{
     validate_header_base_fee, validate_header_extradata, validate_header_gas,
 };
 use reth_primitives::{BlockWithSenders, NodePrimitives, Receipt, SealedBlock, SealedHeader};
-use reth_primitives_traits::{constants::MINIMUM_GAS_LIMIT, BlockBody};
+use reth_primitives_traits::{
+    constants::{GAS_LIMIT_BOUND_DIVISOR, MINIMUM_GAS_LIMIT},
+    BlockBody,
+};
 use std::{fmt::Debug, sync::Arc, time::SystemTime};
 
-/// The bound divisor of the gas limit, used in update calculations.
-pub const GAS_LIMIT_BOUND_DIVISOR: u64 = 1024;
-
 mod validation;
 pub use validation::validate_block_post_execution;
 

crates/ethereum/evm/src/lib.rs

@@ -154,7 +154,7 @@ impl ConfigureEvmEnv for EthEvmConfig {
             self.chain_spec.base_fee_params_at_timestamp(attributes.timestamp),
         );
 
-        let mut gas_limit = U256::from(parent.gas_limit);
+        let mut gas_limit = U256::from(attributes.gas_limit);
 
         // If we are on the London fork boundary, we need to multiply the parent's gas limit by the
         // elasticity multiplier to get the new gas limit.

crates/ethereum/node/Cargo.toml

@@ -27,7 +27,6 @@ reth-consensus.workspace = true
 reth-beacon-consensus.workspace = true
 reth-rpc.workspace = true
 reth-node-api.workspace = true
-reth-node-core.workspace = true
 reth-chainspec.workspace = true
 reth-primitives.workspace = true
 reth-revm = { workspace = true, features = ["std"] }
@@ -43,7 +42,7 @@ eyre.workspace = true
 reth-chainspec.workspace = true
 reth-db.workspace = true
 reth-exex.workspace = true
-reth-node-api.workspace = true
+reth-node-core.workspace = true
 reth-payload-primitives.workspace = true
 reth-e2e-test-utils.workspace = true
 reth-rpc-eth-api.workspace = true

crates/ethereum/node/src/node.rs

@@ -1,7 +1,5 @@
 //! Ethereum Node types config.
 
-use std::sync::Arc;
-
 use reth_basic_payload_builder::{BasicPayloadJobGenerator, BasicPayloadJobGeneratorConfig};
 use reth_beacon_consensus::EthBeaconConsensus;
 use reth_chainspec::ChainSpec;
@@ -24,7 +22,6 @@ use reth_node_builder::{
     rpc::{EngineValidatorBuilder, RpcAddOns},
     BuilderContext, Node, NodeAdapter, NodeComponentsBuilder, PayloadBuilderConfig, PayloadTypes,
 };
-use reth_node_core::version::default_extra_data_bytes;
 use reth_payload_builder::{PayloadBuilderHandle, PayloadBuilderService};
 use reth_primitives::{EthPrimitives, PooledTransactionsElement};
 use reth_provider::{CanonStateSubscriptions, EthStorage};
@@ -35,6 +32,7 @@ use reth_transaction_pool::{
     TransactionValidationTaskExecutor,
 };
 use reth_trie_db::MerklePatriciaTrie;
+use std::sync::Arc;
 
 use crate::{EthEngineTypes, EthEvmConfig};
 
@@ -230,24 +228,9 @@ where
 }
 
 /// A basic ethereum payload service.
-#[derive(Clone, Debug)]
-pub struct EthereumPayloadBuilder {
-    /// Payload builder configuration.
-    config: EthereumBuilderConfig,
-}
-
-impl Default for EthereumPayloadBuilder {
-    fn default() -> Self {
-        Self { config: EthereumBuilderConfig::new(default_extra_data_bytes()) }
-    }
-}
-
-impl EthereumPayloadBuilder {
-    /// Create new ethereum payload builder.
-    pub const fn new(config: EthereumBuilderConfig) -> Self {
-        Self { config }
-    }
-}
+#[derive(Clone, Default, Debug)]
+#[non_exhaustive]
+pub struct EthereumPayloadBuilder;
 
 impl EthereumPayloadBuilder {
     /// A helper method initializing [`PayloadBuilderService`] with the given EVM config.
@@ -270,9 +253,11 @@ impl EthereumPayloadBuilder {
             PayloadBuilderAttributes = EthPayloadBuilderAttributes,
         >,
     {
-        let payload_builder =
-            reth_ethereum_payload_builder::EthereumPayloadBuilder::new(evm_config, self.config);
         let conf = ctx.payload_builder_config();
+        let payload_builder = reth_ethereum_payload_builder::EthereumPayloadBuilder::new(
+            evm_config,
+            EthereumBuilderConfig::new(conf.extradata_bytes()).with_gas_limit(conf.gas_limit()),
+        );
 
         let payload_job_config = BasicPayloadJobGeneratorConfig::default()
             .interval(conf.interval())

crates/ethereum/payload/Cargo.toml

@@ -14,6 +14,7 @@ workspace = true
 [dependencies]
 # reth
 reth-primitives.workspace = true
+reth-primitives-traits.workspace = true
 reth-revm.workspace = true
 reth-transaction-pool.workspace = true
 reth-payload-builder.workspace = true

crates/ethereum/payload/src/config.rs

@@ -1,16 +1,26 @@
+use alloy_eips::eip1559::ETHEREUM_BLOCK_GAS_LIMIT;
 use alloy_primitives::Bytes;
+use reth_primitives_traits::constants::GAS_LIMIT_BOUND_DIVISOR;
 
 /// Settings for the Ethereum builder.
 #[derive(PartialEq, Eq, Clone, Debug)]
 pub struct EthereumBuilderConfig {
     /// Block extra data.
     pub extra_data: Bytes,
+    /// Desired gas limit.
+    pub desired_gas_limit: u64,
 }
 
 impl EthereumBuilderConfig {
     /// Create new payload builder config.
     pub const fn new(extra_data: Bytes) -> Self {
-        Self { extra_data }
+        Self { extra_data, desired_gas_limit: ETHEREUM_BLOCK_GAS_LIMIT }
+    }
+
+    /// Set desired gas limit.
+    pub const fn with_gas_limit(mut self, desired_gas_limit: u64) -> Self {
+        self.desired_gas_limit = desired_gas_limit;
+        self
     }
 }
 
@@ -19,4 +29,19 @@ impl EthereumBuilderConfig {
     pub fn extra_data(&self) -> Bytes {
         self.extra_data.clone()
     }
+
+    /// Returns the gas limit for the next block based
+    /// on parent and desired gas limits.
+    pub fn gas_limit(&self, parent_gas_limit: u64) -> u64 {
+        calculate_block_gas_limit(parent_gas_limit, self.desired_gas_limit)
+    }
+}
+
+/// Calculate the gas limit for the next block based on parent and desired gas limits.
+/// Ref: <https://github.com/ethereum/go-ethereum/blob/88cbfab332c96edfbe99d161d9df6a40721bd786/core/block_validator.go#L166>
+pub fn calculate_block_gas_limit(parent_gas_limit: u64, desired_gas_limit: u64) -> u64 {
+    let delta = (parent_gas_limit / GAS_LIMIT_BOUND_DIVISOR).saturating_sub(1);
+    let min_gas_limit = parent_gas_limit - delta;
+    let max_gas_limit = parent_gas_limit + delta;
+    desired_gas_limit.clamp(min_gas_limit, max_gas_limit)
 }

crates/ethereum/payload/src/lib.rs

@@ -88,6 +88,7 @@ where
             timestamp: config.attributes.timestamp(),
             suggested_fee_recipient: config.attributes.suggested_fee_recipient(),
             prev_randao: config.attributes.prev_randao(),
+            gas_limit: self.builder_config.gas_limit(parent.gas_limit),
         };
         self.evm_config.next_cfg_and_block_env(parent, next_attributes)
     }