laconicd/x/evm/keeper/eip1559.go
Federico Kunze Küllmer 1ad9b4c1a5
evm: EIP1559 & go-ethereum related updates (#469)
* updates

* more changes

* proto updates

* tidy

* v1beta1

* update buf

* lint

* comments

* typo
2021-08-25 14:45:51 +00:00

90 lines
3.1 KiB
Go

package keeper
import (
"math/big"
sdk "github.com/cosmos/cosmos-sdk/types"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/common/math"
// "github.com/ethereum/go-ethereum/params"
"github.com/tharsis/ethermint/x/evm/types"
)
// CalculateBaseFee calculates the base fee for the current block. This is only calculated once per
// block during EndBlock. If the NoBaseFee parameter is enabled, this function returns nil.
// NOTE: This code is inspired from the go-ethereum EIP1559 implementation and adapted to Cosmos SDK-based
// chains. For the canonical code refer to: https://github.com/ethereum/go-ethereum/blob/master/consensus/misc/eip1559.go
func (k Keeper) CalculateBaseFee(ctx sdk.Context) *big.Int {
consParams := ctx.ConsensusParams()
params := k.GetParams(ctx)
if params.NoBaseFee {
return nil
}
chainConfig := params.ChainConfig
cfg := chainConfig.EthereumConfig(k.eip155ChainID)
// If the current block is the first EIP-1559 block, return the InitialBaseFee.
// if !chainConfig.EthereumConfig(k.eip155ChainID).IsLondon(big.NewInt(ctx.BlockHeight())) {
// return new(big.Int).SetUint64(types.InitialBaseFee)
// }
// FIXME: remove and uncomment line above
height := big.NewInt(ctx.BlockHeight())
rules := cfg.Rules(height)
if rules.IsBerlin || cfg.IsMuirGlacier(height) || rules.IsIstanbul || rules.IsByzantium || rules.IsConstantinople {
return new(big.Int).SetUint64(types.InitialBaseFee)
}
// get the block gas used and the base fee values for the parent block.
parentBaseFee := k.GetBaseFee(ctx)
parentGasUsed := k.GetBlockGasUsed(ctx)
gasLimit := new(big.Int).SetUint64(math.MaxUint64)
if consParams != nil && consParams.Block.MaxGas > -1 {
gasLimit = big.NewInt(consParams.Block.MaxGas)
}
parentGasTargetBig := new(big.Int).Div(gasLimit, big.NewInt(types.ElasticityMultiplier)) // TODO: update to geth
if !parentGasTargetBig.IsUint64() {
return new(big.Int).SetUint64(types.InitialBaseFee) // TODO: update to geth
}
parentGasTarget := parentGasTargetBig.Uint64()
baseFeeChangeDenominator := new(big.Int).SetUint64(types.BaseFeeChangeDenominator) // TODO: update to geth
// If the parent gasUsed is the same as the target, the baseFee remains unchanged.
if parentGasUsed == parentGasTarget {
return new(big.Int).Set(parentBaseFee)
}
if parentGasUsed > parentGasTarget {
// If the parent block used more gas than its target, the baseFee should increase.
gasUsedDelta := new(big.Int).SetUint64(parentGasUsed - parentGasTarget)
x := new(big.Int).Mul(parentBaseFee, gasUsedDelta)
y := x.Div(x, parentGasTargetBig)
baseFeeDelta := math.BigMax(
x.Div(y, baseFeeChangeDenominator),
common.Big1,
)
return x.Add(parentBaseFee, baseFeeDelta)
}
// Otherwise if the parent block used less gas than its target, the baseFee should decrease.
gasUsedDelta := new(big.Int).SetUint64(parentGasTarget - parentGasUsed)
x := new(big.Int).Mul(parentBaseFee, gasUsedDelta)
y := x.Div(x, parentGasTargetBig)
baseFeeDelta := x.Div(y, baseFeeChangeDenominator)
return math.BigMax(
x.Sub(parentBaseFee, baseFeeDelta),
common.Big0,
)
}