feat: EIP-7840

crates/consensus/src/block/header.rs

@@ -1,10 +1,9 @@
 use crate::constants::{EMPTY_OMMER_ROOT_HASH, EMPTY_ROOT_HASH};
 use alloc::vec::Vec;
 use alloy_eips::{
-    calc_blob_gasprice,
     eip1559::{calc_next_block_base_fee, BaseFeeParams},
     eip1898::BlockWithParent,
-    eip4844::{self},
+    eip7840::BlobParams,
     merge::ALLOWED_FUTURE_BLOCK_TIME_SECONDS,
     BlockNumHash,
 };
@@ -191,17 +190,17 @@ impl Header {
     /// Returns the blob fee for _this_ block according to the EIP-4844 spec.
     ///
     /// Returns `None` if `excess_blob_gas` is None
-    pub fn blob_fee(&self) -> Option<u128> {
-        self.excess_blob_gas.map(calc_blob_gasprice)
+    pub fn blob_fee(&self, blob_params: BlobParams) -> Option<u128> {
+        Some(blob_params.calc_blob_fee(self.excess_blob_gas?))
     }
 
     /// Returns the blob fee for the next block according to the EIP-4844 spec.
     ///
     /// Returns `None` if `excess_blob_gas` is None.
     ///
     /// See also [Self::next_block_excess_blob_gas]
-    pub fn next_block_blob_fee(&self) -> Option<u128> {
-        Some(eip4844::calc_blob_gasprice(self.next_block_excess_blob_gas()?))
+    pub fn next_block_blob_fee(&self, blob_params: BlobParams) -> Option<u128> {
+        Some(blob_params.calc_blob_fee(self.next_block_excess_blob_gas(blob_params)?))
     }
 
     /// Calculate base fee for next block according to the EIP-1559 spec.
@@ -220,11 +219,8 @@ impl Header {
     /// spec.
     ///
     /// Returns a `None` if no excess blob gas is set, no EIP-4844 support
-    pub fn next_block_excess_blob_gas(&self) -> Option<u64> {
-        let excess_blob_gas = self.excess_blob_gas?;
-        let blob_gas_used = self.blob_gas_used?;
-
-        Some(eip4844::calc_excess_blob_gas(excess_blob_gas, blob_gas_used))
+    pub fn next_block_excess_blob_gas(&self, blob_params: BlobParams) -> Option<u64> {
+        Some(blob_params.next_block_excess_blob_gas(self.excess_blob_gas?, self.blob_gas_used?))
     }
 
     /// Calculate a heuristic for the in-memory size of the [Header].
@@ -602,28 +598,25 @@ pub trait BlockHeader {
     /// Returns the blob fee for _this_ block according to the EIP-4844 spec.
     ///
     /// Returns `None` if `excess_blob_gas` is None
-    fn blob_fee(&self) -> Option<u128> {
-        self.excess_blob_gas().map(calc_blob_gasprice)
+    fn blob_fee(&self, blob_params: BlobParams) -> Option<u128> {
+        Some(blob_params.calc_blob_fee(self.excess_blob_gas()?))
     }
 
     /// Calculate excess blob gas for the next block according to the EIP-4844
     /// spec.
     ///
     /// Returns a `None` if no excess blob gas is set, no EIP-4844 support
-    fn next_block_excess_blob_gas(&self) -> Option<u64> {
-        let excess_blob_gas = self.excess_blob_gas()?;
-        let blob_gas_used = self.blob_gas_used()?;
-
-        Some(eip4844::calc_excess_blob_gas(excess_blob_gas, blob_gas_used))
+    fn next_block_excess_blob_gas(&self, blob_params: BlobParams) -> Option<u64> {
+        Some(blob_params.next_block_excess_blob_gas(self.excess_blob_gas()?, self.blob_gas_used()?))
     }
 
     /// Returns the blob fee for the next block according to the EIP-4844 spec.
     ///
     /// Returns `None` if `excess_blob_gas` is None.
     ///
     /// See also [BlockHeader::next_block_excess_blob_gas]
-    fn next_block_blob_fee(&self) -> Option<u128> {
-        Some(eip4844::calc_blob_gasprice(self.next_block_excess_blob_gas()?))
+    fn next_block_blob_fee(&self, blob_params: BlobParams) -> Option<u128> {
+        Some(blob_params.calc_blob_fee(self.next_block_excess_blob_gas(blob_params)?))
     }
 
     /// Calculate base fee for next block according to the EIP-1559 spec.

crates/eips/src/eip4844/mod.rs

@@ -24,6 +24,8 @@ pub use sidecar::*;
 
 use alloy_primitives::{b256, FixedBytes, B256, U256};
 
+use crate::eip7840;
+
 /// The modulus of the BLS group used in the KZG commitment scheme. All field
 /// elements contained in a blob MUST be STRICTLY LESS than this value.
 pub const BLS_MODULUS_BYTES: B256 =
@@ -125,7 +127,8 @@ pub fn kzg_to_versioned_hash(commitment: &[u8]) -> B256 {
 /// (`calc_excess_blob_gas`).
 #[inline]
 pub const fn calc_excess_blob_gas(parent_excess_blob_gas: u64, parent_blob_gas_used: u64) -> u64 {
-    (parent_excess_blob_gas + parent_blob_gas_used).saturating_sub(TARGET_DATA_GAS_PER_BLOCK)
+    eip7840::BlobParams::cancun()
+        .next_block_excess_blob_gas(parent_excess_blob_gas, parent_blob_gas_used)
 }
 
 /// Calculates the blob gas price from the header's excess blob gas field.
@@ -134,11 +137,7 @@ pub const fn calc_excess_blob_gas(parent_excess_blob_gas: u64, parent_blob_gas_u
 /// (`get_blob_gasprice`).
 #[inline]
 pub const fn calc_blob_gasprice(excess_blob_gas: u64) -> u128 {
-    fake_exponential(
-        BLOB_TX_MIN_BLOB_GASPRICE,
-        excess_blob_gas as u128,
-        BLOB_GASPRICE_UPDATE_FRACTION,
-    )
+    eip7840::BlobParams::cancun().calc_blob_fee(excess_blob_gas)
 }
 
 /// Approximates `factor * e ** (numerator / denominator)` using Taylor expansion.

crates/eips/src/eip7840.rs

@@ -0,0 +1,68 @@
+//! Contains constants and utility functions for [EIP-7840](https://github.com/ethereum/EIPs/tree/master/EIPS/eip-7840.md)
+
+use crate::{eip4844, eip7691};
+
+/// A single item of `blobSchedule` defined in EIP-7840.
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
+pub struct BlobScheduleItem {
+    /// Target blob count for the block.
+    #[cfg_attr(feature = "serde", serde(rename = "target"))]
+    pub target_blob_count: u64,
+    /// Max blob count for the block.
+    #[cfg_attr(feature = "serde", serde(rename = "max"))]
+    pub max_blob_count: u64,
+}
+
+/// Configuration for the blob-related calculations.
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub struct BlobParams {
+    /// Target blob count for the block.
+    pub target_blob_count: u64,
+    /// Max blob count for the block.
+    pub max_blob_count: u64,
+    /// Update fraction for excess blob gas calculation.
+    pub update_fraction: u128,
+    /// Minimum gas price for a data blob.
+    pub min_blob_fee: u128,
+}
+
+impl BlobParams {
+    /// Returns [`BlobParams`] configuration activated with Cancun hardfork.
+    pub const fn cancun() -> Self {
+        Self {
+            target_blob_count: eip4844::TARGET_BLOBS_PER_BLOCK,
+            max_blob_count: eip4844::MAX_BLOBS_PER_BLOCK as u64,
+            update_fraction: eip4844::BLOB_GASPRICE_UPDATE_FRACTION,
+            min_blob_fee: eip4844::BLOB_TX_MIN_BLOB_GASPRICE,
+        }
+    }
+
+    /// Returns [`BlobParams`] configuration activated with Prague hardfork.
+    pub const fn prague() -> Self {
+        Self {
+            target_blob_count: eip7691::TARGET_BLOBS_PER_BLOCK_ELECTRA,
+            max_blob_count: eip7691::MAX_BLOBS_PER_BLOCK_ELECTRA,
+            update_fraction: eip7691::BLOB_GASPRICE_UPDATE_FRACTION_PECTRA,
+            min_blob_fee: eip4844::BLOB_TX_MIN_BLOB_GASPRICE,
+        }
+    }
+
+    /// Calculates the `excess_blob_gas` value for the next block based on the current block
+    /// `excess_blob_gas` and `blob_gas_used`.
+    #[inline]
+    pub const fn next_block_excess_blob_gas(
+        &self,
+        excess_blob_gas: u64,
+        blob_gas_used: u64,
+    ) -> u64 {
+        (excess_blob_gas + blob_gas_used)
+            .saturating_sub(eip4844::DATA_GAS_PER_BLOB * self.target_blob_count)
+    }
+
+    /// Calculates the blob fee for block based on its `excess_blob_gas`.
+    #[inline]
+    pub const fn calc_blob_fee(&self, excess_blob_gas: u64) -> u128 {
+        eip4844::fake_exponential(self.min_blob_fee, excess_blob_gas as u128, self.update_fraction)
+    }
+}

crates/eips/src/lib.rs

@@ -45,3 +45,5 @@ pub mod eip7685;
 pub mod eip7691;
 
 pub mod eip7702;
+
+pub mod eip7840;

crates/genesis/Cargo.toml

@@ -19,6 +19,7 @@ rustdoc-args = ["--cfg", "docsrs"]
 workspace = true
 
 [dependencies]
+alloy-eips = { workspace = true, features = ["serde"] }
 alloy-primitives.workspace = true
 alloy-serde.workspace = true
 alloy-trie = { workspace = true, features = ["ethereum"] }

crates/genesis/src/lib.rs

@@ -12,6 +12,7 @@
 extern crate alloc;
 
 use alloc::{collections::BTreeMap, string::String};
+use alloy_eips::eip7840::BlobScheduleItem;
 use alloy_primitives::{keccak256, Address, Bytes, B256, U256};
 use alloy_serde::{storage::deserialize_storage_map, ttd::deserialize_json_ttd_opt, OtherFields};
 use alloy_trie::{TrieAccount, EMPTY_ROOT_HASH, KECCAK_EMPTY};
@@ -479,6 +480,12 @@ pub struct ChainConfig {
     /// The deposit contract address
     #[serde(default, skip_serializing_if = "Option::is_none")]
     pub deposit_contract_address: Option<Address>,
+
+    /// The blob schedule for the chain, indexed by hardfork name.
+    ///
+    /// See [EIP-7840](https://github.com/ethereum/EIPs/tree/master/EIPS/eip-7840.md).
+    #[serde(default, skip_serializing_if = "BTreeMap::is_empty")]
+    pub blob_schedule: BTreeMap<String, BlobScheduleItem>,
 }
 
 impl ChainConfig {
@@ -604,6 +611,7 @@ impl Default for ChainConfig {
             parlia: None,
             extra_fields: Default::default(),
             deposit_contract_address: None,
+            blob_schedule: Default::default(),
         }
     }
 }

crates/rpc-types-eth/src/block.rs

@@ -11,6 +11,7 @@ use alloy_primitives::{Address, BlockHash, Bloom, Bytes, Sealable, B256, B64, U2
 use alloy_rlp::Encodable;
 use core::ops::{Deref, DerefMut};
 
+use alloy_eips::eip7840::BlobParams;
 pub use alloy_eips::{
     calc_blob_gasprice, calc_excess_blob_gas, BlockHashOrNumber, BlockId, BlockNumHash,
     BlockNumberOrTag, ForkBlock, RpcBlockHash,
@@ -165,16 +166,16 @@ impl<H: BlockHeader> Header<H> {
     /// Returns `None` if `excess_blob_gas` is None.
     ///
     /// See also [Self::next_block_excess_blob_gas]
-    pub fn next_block_blob_fee(&self) -> Option<u128> {
-        self.inner.next_block_blob_fee()
+    pub fn next_block_blob_fee(&self, blob_params: BlobParams) -> Option<u128> {
+        self.inner.next_block_blob_fee(blob_params)
     }
 
     /// Calculate excess blob gas for the next block according to the EIP-4844
     /// spec.
     ///
     /// Returns a `None` if no excess blob gas is set, no EIP-4844 support
-    pub fn next_block_excess_blob_gas(&self) -> Option<u64> {
-        self.inner.next_block_excess_blob_gas()
+    pub fn next_block_excess_blob_gas(&self, blob_params: BlobParams) -> Option<u64> {
+        self.inner.next_block_excess_blob_gas(blob_params)
     }
 }