55 lines
1.8 KiB
Go
55 lines
1.8 KiB
Go
|
// Copyright 2023 The go-ethereum Authors
|
||
|
|
// This file is part of the go-ethereum library.
|
||
|
|
//
|
||
|
|
// The go-ethereum library is free software: you can redistribute it and/or modify
|
||
|
|
// it under the terms of the GNU Lesser General Public License as published by
|
||
|
|
// the Free Software Foundation, either version 3 of the License, or
|
||
|
|
// (at your option) any later version.
|
||
|
|
//
|
||
|
|
// The go-ethereum library is distributed in the hope that it will be useful,
|
||
|
|
// but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||
|
|
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||
|
|
// GNU Lesser General Public License for more details.
|
||
|
|
//
|
||
|
|
// You should have received a copy of the GNU Lesser General Public License
|
||
|
|
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
|
||
|
|
|
||
|
|
package misc
|
||
|
|
|
||
|
|
import (
|
||
|
|
"math/big"
|
||
|
|
|
||
|
|
"github.com/ethereum/go-ethereum/params"
|
||
|
|
)
|
||
|
|
|
||
|
|
var (
|
||
|
|
minDataGasPrice = big.NewInt(params.BlobTxMinDataGasprice)
|
||
|
|
dataGaspriceUpdateFraction = big.NewInt(params.BlobTxDataGaspriceUpdateFraction)
|
||
|
|
)
|
||
|
|
|
||
|
|
// CalcBlobFee calculates the blobfee from the header's excess data gas field.
|
||
|
|
func CalcBlobFee(excessDataGas *big.Int) *big.Int {
|
||
|
|
// If this block does not yet have EIP-4844 enabled, return the starting fee
|
||
|
|
if excessDataGas == nil {
|
||
|
|
return big.NewInt(params.BlobTxMinDataGasprice)
|
||
|
|
}
|
||
|
|
return fakeExponential(minDataGasPrice, excessDataGas, dataGaspriceUpdateFraction)
|
||
|
|
}
|
||
|
|
|
||
|
|
// fakeExponential approximates factor * e ** (numerator / denominator) using
|
||
|
|
// Taylor expansion.
|
||
|
|
func fakeExponential(factor, numerator, denominator *big.Int) *big.Int {
|
||
|
|
var (
|
||
|
|
output = new(big.Int)
|
||
|
|
accum = new(big.Int).Mul(factor, denominator)
|
||
|
|
)
|
||
|
|
for i := 1; accum.Sign() > 0; i++ {
|
||
|
|
output.Add(output, accum)
|
||
|
|
|
||
|
|
accum.Mul(accum, numerator)
|
||
|
|
accum.Div(accum, denominator)
|
||
|
|
accum.Div(accum, big.NewInt(int64(i)))
|
||
|
|
}
|
||
|
|
return output.Div(output, denominator)
|
||
|
|
}
|