From e9771ac497c117a8c8574e15d6543b124ebfa0a5 Mon Sep 17 00:00:00 2001
From: Tran Tien Duc <trantienduchn@gmail.com>
Date: Wed, 11 Dec 2024 13:57:12 +0700
Subject: [PATCH] internal/ethapi: implement eth_blobBaseFee

---
 eth/api_backend.go          | 8 ++++++++
 internal/ethapi/api.go      | 5 +++++
 internal/ethapi/api_test.go | 3 +++
 internal/ethapi/backend.go  | 1 +
 internal/jsre/deps/web3.js  | 5 +++++
 les/api_backend.go          | 8 ++++++++
 6 files changed, 30 insertions(+)

diff --git a/eth/api_backend.go b/eth/api_backend.go
index 93637e7c17..52c0520b07 100644
--- a/eth/api_backend.go
+++ b/eth/api_backend.go
@@ -22,6 +22,7 @@ import (
 	"math/big"
 	"time"
 
+	"github.com/ethereum/go-ethereum/consensus/misc/eip4844"
 	"github.com/ethereum/go-ethereum/eth/tracers"
 
 	"github.com/ethereum/go-ethereum"
@@ -357,6 +358,13 @@ func (b *EthAPIBackend) FeeHistory(ctx context.Context, blockCount int, lastBloc
 	return b.gpo.FeeHistory(ctx, blockCount, lastBlock, rewardPercentiles)
 }
 
+func (b *EthAPIBackend) BlobBaseFee(ctx context.Context) *big.Int {
+	if excess := b.CurrentHeader().ExcessBlobGas; excess != nil {
+		return eip4844.CalcBlobFee(*excess)
+	}
+	return nil
+}
+
 func (b *EthAPIBackend) ChainDb() ethdb.Database {
 	return b.eth.ChainDb()
 }
diff --git a/internal/ethapi/api.go b/internal/ethapi/api.go
index 4e4fe97044..1369e528ad 100644
--- a/internal/ethapi/api.go
+++ b/internal/ethapi/api.go
@@ -130,6 +130,11 @@ func (s *PublicEthereumAPI) FeeHistory(ctx context.Context, blockCount rpc.Decim
 	return results, nil
 }
 
+// BlobBaseFee returns the base fee for blob gas at the current head.
+func (s *PublicEthereumAPI) BlobBaseFee(ctx context.Context) *hexutil.Big {
+	return (*hexutil.Big)(s.b.BlobBaseFee(ctx))
+}
+
 // Syncing returns false in case the node is currently not syncing with the network. It can be up to date or has not
 // yet received the latest block headers from its pears. In case it is synchronizing:
 // - startingBlock: block number this node started to synchronise from
diff --git a/internal/ethapi/api_test.go b/internal/ethapi/api_test.go
index e4226fb304..eecee740ae 100644
--- a/internal/ethapi/api_test.go
+++ b/internal/ethapi/api_test.go
@@ -451,6 +451,9 @@ func (b testBackend) SuggestGasTipCap(ctx context.Context) (*big.Int, error) {
 func (b testBackend) FeeHistory(ctx context.Context, blockCount int, lastBlock rpc.BlockNumber, rewardPercentiles []float64) (*big.Int, [][]*big.Int, []*big.Int, []float64, error) {
 	return nil, nil, nil, nil, nil
 }
+func (b testBackend) BlobBaseFee(ctx context.Context) *big.Int {
+	return new(big.Int)
+}
 func (b testBackend) ChainDb() ethdb.Database           { return b.db }
 func (b testBackend) AccountManager() *accounts.Manager { return b.accman }
 func (b testBackend) ExtRPCEnabled() bool               { return false }
diff --git a/internal/ethapi/backend.go b/internal/ethapi/backend.go
index bb9d564be1..4db8458951 100644
--- a/internal/ethapi/backend.go
+++ b/internal/ethapi/backend.go
@@ -45,6 +45,7 @@ type Backend interface {
 
 	SuggestGasTipCap(ctx context.Context) (*big.Int, error)
 	FeeHistory(ctx context.Context, blockCount int, lastBlock rpc.BlockNumber, rewardPercentiles []float64) (*big.Int, [][]*big.Int, []*big.Int, []float64, error)
+	BlobBaseFee(ctx context.Context) *big.Int
 	ChainDb() ethdb.Database
 	AccountManager() *accounts.Manager
 	ExtRPCEnabled() bool
diff --git a/internal/jsre/deps/web3.js b/internal/jsre/deps/web3.js
index c130f80dea..ec69de09ce 100644
--- a/internal/jsre/deps/web3.js
+++ b/internal/jsre/deps/web3.js
@@ -5494,6 +5494,11 @@ var properties = function () {
             getter: 'eth_gasPrice',
             outputFormatter: formatters.outputBigNumberFormatter
         }),
+        new Property({
+            name: 'blobBaseFee',
+            getter: 'eth_blobBaseFee',
+            outputFormatter: formatters.outputBigNumberFormatter
+        }),
         new Property({
             name: 'accounts',
             getter: 'eth_accounts'
diff --git a/les/api_backend.go b/les/api_backend.go
index 00091b434a..4054e397a6 100644
--- a/les/api_backend.go
+++ b/les/api_backend.go
@@ -22,6 +22,7 @@ import (
 	"math/big"
 	"time"
 
+	"github.com/ethereum/go-ethereum/consensus/misc/eip4844"
 	"github.com/ethereum/go-ethereum/eth/tracers"
 
 	"github.com/ethereum/go-ethereum"
@@ -303,6 +304,13 @@ func (b *LesApiBackend) FeeHistory(ctx context.Context, blockCount int, lastBloc
 	return b.gpo.FeeHistory(ctx, blockCount, lastBlock, rewardPercentiles)
 }
 
+func (b *LesApiBackend) BlobBaseFee(ctx context.Context) *big.Int {
+	if excess := b.CurrentHeader().ExcessBlobGas; excess != nil {
+		return eip4844.CalcBlobFee(*excess)
+	}
+	return nil
+}
+
 func (b *LesApiBackend) ChainDb() ethdb.Database {
 	return b.eth.chainDb
 }