feat: update base fee via contract (#1189)

* Revert "feat: update base fee via cli (#1183)"

This reverts commit 0b6f8f1.

* feat: update l2 base fee via system contract

* nit

* bump version

* fix tests

* update contract abi

* init coefficients on startup

* nil check

* update test

* update txpool gas price

* init with default value

* update scroll sepolia and mainnet contract addresses

* nit

* update txpool min price during startup

* print stack trace for worker panic

* fix event parsing

* fix log

* improve txpool update logic

* move initializeL2BaseFeeCoefficients to misc package

* bump version

* add API to query L2 base fee coefficients via console

* fix code review suggestion

Author: Thegaram

cmd/geth/main.go

@@ -29,6 +29,7 @@ import (
 	"github.com/scroll-tech/go-ethereum/accounts/keystore"
 	"github.com/scroll-tech/go-ethereum/cmd/utils"
 	"github.com/scroll-tech/go-ethereum/common"
+	"github.com/scroll-tech/go-ethereum/consensus/misc"
 	"github.com/scroll-tech/go-ethereum/console/prompt"
 	"github.com/scroll-tech/go-ethereum/eth"
 	"github.com/scroll-tech/go-ethereum/eth/downloader"
@@ -185,8 +186,6 @@ var (
 		utils.DARecoverySignBlocksFlag,
 		utils.DARecoveryL2EndBlockFlag,
 		utils.DARecoveryProduceBlocksFlag,
-		utils.L2BaseFeeScalarFlag,
-		utils.L2BaseFeeOverheadFlag,
 	}
 
 	rpcFlags = []cli.Flag{
@@ -455,8 +454,9 @@ func startNode(ctx *cli.Context, stack *node.Node, backend ethapi.Backend) {
 			utils.Fatalf("Ethereum service not running")
 		}
 		// Set the gas price to the limits from the CLI and start mining
-		gasprice := utils.GlobalBig(ctx, utils.MinerGasPriceFlag.Name)
-		ethBackend.TxPool().SetGasPrice(gasprice)
+		// gasprice := utils.GlobalBig(ctx, utils.MinerGasPriceFlag.Name)
+		// ethBackend.TxPool().SetGasPrice(gasprice)
+		ethBackend.TxPool().SetGasPrice(misc.MinBaseFee()) // override configured min gas price
 		ethBackend.TxPool().SetIsMiner(true)
 		// start mining
 		threads := ctx.GlobalInt(utils.MinerThreadsFlag.Name)

cmd/geth/usage.go

@@ -236,8 +236,6 @@ var AppHelpFlagGroups = []flags.FlagGroup{
 			utils.L1DeploymentBlockFlag,
 			utils.L1DisableMessageQueueV2Flag,
 			utils.RollupVerifyEnabledFlag,
-			utils.L2BaseFeeScalarFlag,
-			utils.L2BaseFeeOverheadFlag,
 			utils.DASyncEnabledFlag,
 			utils.DABlobScanAPIEndpointFlag,
 			utils.DABlockNativeAPIEndpointFlag,

cmd/utils/flags.go

@@ -47,7 +47,6 @@ import (
 	"github.com/scroll-tech/go-ethereum/consensus"
 	"github.com/scroll-tech/go-ethereum/consensus/clique"
 	"github.com/scroll-tech/go-ethereum/consensus/ethash"
-	"github.com/scroll-tech/go-ethereum/consensus/misc"
 	"github.com/scroll-tech/go-ethereum/core"
 	"github.com/scroll-tech/go-ethereum/core/rawdb"
 	"github.com/scroll-tech/go-ethereum/core/vm"
@@ -935,18 +934,6 @@ var (
 		Name:  "da.recovery.produceblocks",
 		Usage: "Produce unsigned blocks after L1 recovery for permissionless batch submission",
 	}
-
-	// L2 base fee settings
-	L2BaseFeeScalarFlag = BigFlag{
-		Name:  "basefee.scalar",
-		Usage: "Scalar used in the l2 base fee formula. Signer nodes will use this for computing the next block's base fee. Follower nodes will use this in RPC.",
-		Value: misc.DefaultBaseFeeScalar,
-	}
-	L2BaseFeeOverheadFlag = BigFlag{
-		Name:  "basefee.overhead",
-		Usage: "Overhead used in the l2 base fee formula. Signer nodes will use this for computing the next block's base fee. Follower nodes will use this in RPC.",
-		Value: misc.DefaultBaseFeeOverhead,
-	}
 )
 
 // MakeDataDir retrieves the currently requested data directory, terminating
@@ -1722,29 +1709,6 @@ func setDA(ctx *cli.Context, cfg *ethconfig.Config) {
 	}
 }
 
-func setBaseFee(ctx *cli.Context, cfg *ethconfig.Config) {
-	cfg.BaseFeeScalar = misc.DefaultBaseFeeScalar
-	if ctx.GlobalIsSet(L2BaseFeeScalarFlag.Name) {
-		cfg.BaseFeeScalar = GlobalBig(ctx, L2BaseFeeScalarFlag.Name)
-	}
-	cfg.BaseFeeOverhead = misc.DefaultBaseFeeOverhead
-	if ctx.GlobalIsSet(L2BaseFeeOverheadFlag.Name) {
-		cfg.BaseFeeOverhead = GlobalBig(ctx, L2BaseFeeOverheadFlag.Name)
-	}
-
-	log.Info("L2 base fee coefficients", "scalar", cfg.BaseFeeScalar, "overhead", cfg.BaseFeeOverhead)
-
-	var minBaseFee uint64
-	if fee := misc.MinBaseFee(cfg.BaseFeeScalar, cfg.BaseFeeOverhead); fee.IsUint64() {
-		minBaseFee = fee.Uint64()
-	}
-
-	if cfg.TxPool.PriceLimit < minBaseFee {
-		log.Warn("Updating txpool price limit to min L2 base fee", "provided", cfg.TxPool.PriceLimit, "updated", minBaseFee)
-		cfg.TxPool.PriceLimit = minBaseFee
-	}
-}
-
 func setMaxBlockRange(ctx *cli.Context, cfg *ethconfig.Config) {
 	if ctx.GlobalIsSet(MaxBlockRangeFlag.Name) {
 		cfg.MaxBlockRange = ctx.GlobalInt64(MaxBlockRangeFlag.Name)
@@ -1821,7 +1785,6 @@ func SetEthConfig(ctx *cli.Context, stack *node.Node, cfg *ethconfig.Config) {
 	setCircuitCapacityCheck(ctx, cfg)
 	setEnableRollupVerify(ctx, cfg)
 	setDA(ctx, cfg)
-	setBaseFee(ctx, cfg)
 	setMaxBlockRange(ctx, cfg)
 	if ctx.GlobalIsSet(ShadowforkPeersFlag.Name) {
 		cfg.ShadowForkPeerIDs = ctx.GlobalStringSlice(ShadowforkPeersFlag.Name)

consensus/misc/eip1559.go

@@ -19,25 +19,67 @@ package misc
 import (
 	"fmt"
 	"math/big"
+	"sync"
 
+	"github.com/scroll-tech/go-ethereum/common"
 	"github.com/scroll-tech/go-ethereum/core/types"
+	"github.com/scroll-tech/go-ethereum/log"
 	"github.com/scroll-tech/go-ethereum/params"
+	"github.com/scroll-tech/go-ethereum/rollup/rcfg"
+	"github.com/scroll-tech/go-ethereum/rpc"
 )
 
-// Protocol-enforced maximum L2 base fee.
-// We would only go above this if L1 base fee hits 2931 Gwei.
-const MaximumL2BaseFee = 10000000000
+const (
+	// Protocol-enforced maximum L2 base fee.
+	// We would only go above this if L1 base fee hits 2931 Gwei.
+	MaximumL2BaseFee = 10000000000
+
+	// L2 base fee fallback values, in case the L2 system contract
+	// is not deployed on not configured yet.
+	DefaultBaseFeeOverhead = 15680000
+	DefaultBaseFeeScalar   = 34000000000000
+)
 
 // L2 base fee formula constants and defaults.
 // l2BaseFee = (l1BaseFee * scalar) / PRECISION + overhead.
 // `scalar` accounts for finalization costs. `overhead` accounts for sequencing and proving costs.
-// we use 1e18 for precision to match the contract implementation.
 var (
-	BaseFeePrecision       = new(big.Int).SetUint64(1e18)
-	DefaultBaseFeeScalar   = new(big.Int).SetUint64(34000000000000)
-	DefaultBaseFeeOverhead = new(big.Int).SetUint64(15680000)
+	// We use 1e18 for precision to match the contract implementation.
+	BaseFeePrecision = new(big.Int).SetUint64(1e18)
+
+	// scalar and overhead are updated automatically in `Blockchain.writeBlockWithState`.
+	baseFeeScalar   = big.NewInt(0)
+	baseFeeOverhead = big.NewInt(0)
+
+	lock sync.RWMutex
 )
 
+func ReadL2BaseFeeCoefficients() (scalar *big.Int, overhead *big.Int) {
+	lock.RLock()
+	defer lock.RUnlock()
+	return new(big.Int).Set(baseFeeScalar), new(big.Int).Set(baseFeeOverhead)
+}
+
+func UpdateL2BaseFeeOverhead(newOverhead *big.Int) {
+	if newOverhead == nil {
+		log.Error("Failed to set L2 base fee overhead, new value is <nil>")
+		return
+	}
+	lock.Lock()
+	defer lock.Unlock()
+	baseFeeOverhead.Set(newOverhead)
+}
+
+func UpdateL2BaseFeeScalar(newScalar *big.Int) {
+	if newScalar == nil {
+		log.Error("Failed to set L2 base fee scalar, new value is <nil>")
+		return
+	}
+	lock.Lock()
+	defer lock.Unlock()
+	baseFeeScalar.Set(newScalar)
+}
+
 // VerifyEip1559Header verifies some header attributes which were changed in EIP-1559,
 // - gas limit check
 // - basefee check
@@ -65,20 +107,13 @@ func CalcBaseFee(config *params.ChainConfig, parent *types.Header, parentL1BaseF
 		return big.NewInt(10000000) // 0.01 Gwei
 	}
 
-	scalar := config.Scroll.BaseFeeScalar
-	if scalar == nil {
-		scalar = DefaultBaseFeeScalar
-	}
-	overhead := config.Scroll.BaseFeeOverhead
-	if overhead == nil {
-		overhead = DefaultBaseFeeOverhead
-	}
-
+	scalar, overhead := ReadL2BaseFeeCoefficients()
 	return calcBaseFee(scalar, overhead, parentL1BaseFee)
 }
 
-// MinBaseFee calculates the minimum L2 base fee based on the configured coefficients.
-func MinBaseFee(scalar, overhead *big.Int) *big.Int {
+// MinBaseFee calculates the minimum L2 base fee based on the current coefficients.
+func MinBaseFee() *big.Int {
+	scalar, overhead := ReadL2BaseFeeCoefficients()
 	return calcBaseFee(scalar, overhead, big.NewInt(0))
 }
 
@@ -94,3 +129,60 @@ func calcBaseFee(scalar, overhead, parentL1BaseFee *big.Int) *big.Int {
 
 	return baseFee
 }
+
+type State interface {
+	GetState(addr common.Address, hash common.Hash) common.Hash
+}
+
+func InitializeL2BaseFeeCoefficients(chainConfig *params.ChainConfig, state State) error {
+	overhead := common.Big0
+	scalar := common.Big0
+
+	if l2SystemConfig := chainConfig.Scroll.L2SystemConfigAddress(); l2SystemConfig != (common.Address{}) {
+		overhead = state.GetState(l2SystemConfig, rcfg.L2BaseFeeOverheadSlot).Big()
+		scalar = state.GetState(l2SystemConfig, rcfg.L2BaseFeeScalarSlot).Big()
+	} else {
+		log.Warn("L2SystemConfig address is not configured")
+	}
+
+	// fallback to default if contract is not deployed or configured yet
+	if overhead.Cmp(common.Big0) == 0 {
+		overhead = big.NewInt(DefaultBaseFeeOverhead)
+	}
+	if scalar.Cmp(common.Big0) == 0 {
+		scalar = big.NewInt(DefaultBaseFeeScalar)
+	}
+
+	// update local view of coefficients
+	lock.Lock()
+	defer lock.Unlock()
+	baseFeeOverhead.Set(overhead)
+	baseFeeScalar.Set(scalar)
+	log.Info("Initialized L2 base fee coefficients", "overhead", overhead, "scalar", scalar)
+	return nil
+}
+
+type API struct{}
+
+type L2BaseFeeConfig struct {
+	Scalar   *big.Int `json:"scalar,omitempty"`
+	Overhead *big.Int `json:"overhead,omitempty"`
+}
+
+func (api *API) GetL2BaseFeeConfig() *L2BaseFeeConfig {
+	scalar, overhead := ReadL2BaseFeeCoefficients()
+
+	return &L2BaseFeeConfig{
+		Scalar:   scalar,
+		Overhead: overhead,
+	}
+}
+
+func APIs() []rpc.API {
+	return []rpc.API{{
+		Namespace: "scroll",
+		Version:   "1.0",
+		Service:   &API{},
+		Public:    false,
+	}}
+}

consensus/misc/eip1559_test.go

@@ -122,8 +122,8 @@ func TestCalcBaseFee(t *testing.T) {
 	}
 	for i, test := range tests {
 		config := config()
-		config.Scroll.BaseFeeScalar = big.NewInt(10000000)
-		config.Scroll.BaseFeeOverhead = big.NewInt(1)
+		UpdateL2BaseFeeScalar(big.NewInt(10000000))
+		UpdateL2BaseFeeOverhead(big.NewInt(1))
 		if have, want := CalcBaseFee(config, nil, big.NewInt(test.parentL1BaseFee)), big.NewInt(test.expectedL2BaseFee); have.Cmp(want) != 0 {
 			t.Errorf("test %d: have %d  want %d, ", i, have, want)
 		}
@@ -142,6 +142,8 @@ func TestCalcBaseFee(t *testing.T) {
 		{644149677419355, 10000000000}, // cap at max L2 base fee
 	}
 	for i, test := range testsWithDefaults {
+		UpdateL2BaseFeeScalar(big.NewInt(34000000000000))
+		UpdateL2BaseFeeOverhead(big.NewInt(15680000))
 		if have, want := CalcBaseFee(config(), nil, big.NewInt(test.parentL1BaseFee)), big.NewInt(test.expectedL2BaseFee); have.Cmp(want) != 0 {
 			t.Errorf("test %d: have %d  want %d, ", i, have, want)
 		}
@@ -150,11 +152,15 @@ func TestCalcBaseFee(t *testing.T) {
 
 // TestMinBaseFee assumes all blocks are 1559-blocks
 func TestMinBaseFee(t *testing.T) {
-	if have, want := MinBaseFee(DefaultBaseFeeScalar, DefaultBaseFeeOverhead), big.NewInt(15680000); have.Cmp(want) != 0 {
+	UpdateL2BaseFeeScalar(big.NewInt(34000000000000))
+	UpdateL2BaseFeeOverhead(big.NewInt(15680000))
+	if have, want := MinBaseFee(), big.NewInt(15680000); have.Cmp(want) != 0 {
 		t.Errorf("have %d  want %d, ", have, want)
 	}
 
-	if have, want := MinBaseFee(big.NewInt(10000000), big.NewInt(1)), big.NewInt(1); have.Cmp(want) != 0 {
+	UpdateL2BaseFeeScalar(big.NewInt(10000000))
+	UpdateL2BaseFeeOverhead(big.NewInt(1))
+	if have, want := MinBaseFee(), big.NewInt(1); have.Cmp(want) != 0 {
 		t.Errorf("have %d  want %d, ", have, want)
 	}
 }

core/blockchain.go

@@ -34,6 +34,7 @@ import (
 	"github.com/scroll-tech/go-ethereum/common/mclock"
 	"github.com/scroll-tech/go-ethereum/common/prque"
 	"github.com/scroll-tech/go-ethereum/consensus"
+	"github.com/scroll-tech/go-ethereum/consensus/misc"
 	"github.com/scroll-tech/go-ethereum/core/rawdb"
 	"github.com/scroll-tech/go-ethereum/core/state"
 	"github.com/scroll-tech/go-ethereum/core/state/snapshot"
@@ -45,6 +46,7 @@ import (
 	"github.com/scroll-tech/go-ethereum/log"
 	"github.com/scroll-tech/go-ethereum/metrics"
 	"github.com/scroll-tech/go-ethereum/params"
+	"github.com/scroll-tech/go-ethereum/rollup/l2_system_config"
 	"github.com/scroll-tech/go-ethereum/trie"
 )
 
@@ -55,7 +57,8 @@ var (
 	headTimeGapGauge   = metrics.NewRegisteredGauge("chain/head/timegap", nil)
 	headL1MessageGauge = metrics.NewRegisteredGauge("chain/head/l1msg", nil)
 
-	l2BaseFeeGauge = metrics.NewRegisteredGauge("chain/fees/l2basefee", nil)
+	l2BaseFeeGauge       = metrics.NewRegisteredGauge("chain/fees/l2basefee", nil)
+	l2BaseFeeUpdateTimer = metrics.NewRegisteredTimer("chain/fees/updates", nil)
 
 	accountReadTimer   = metrics.NewRegisteredTimer("chain/account/reads", nil)
 	accountHashTimer   = metrics.NewRegisteredTimer("chain/account/hashes", nil)
@@ -161,6 +164,39 @@ func updateHeadL1msgGauge(block *types.Block) {
 	}
 }
 
+// updateL2BaseFeeCoefficients updates the global L2 base fee coefficients.
+// Coefficient updates are written into L2 state and emit an event.
+// We could use either here; we read from the event to avoid state reads.
+// In the future, if the base fee setting becomes part of block validation,
+// reading from state will be more appropriate.
+func updateL2BaseFeeCoefficients(l2SystemConfigAddress common.Address, logs []*types.Log) {
+	defer func(start time.Time) { l2BaseFeeUpdateTimer.Update(time.Since(start)) }(time.Now())
+
+	for _, l := range logs {
+		if l.Address != l2SystemConfigAddress {
+			continue
+		}
+		switch l.Topics[0] {
+		case l2_system_config.BaseFeeOverheadUpdatedTopic:
+			event, err := l2_system_config.UnpackBaseFeeOverheadUpdatedEvent(*l)
+			if err != nil {
+				log.Error("failed to unpack base fee overhead updated event log", "err", err, "log", *l)
+				break // break from switch, continue loop
+			}
+			misc.UpdateL2BaseFeeOverhead(event.NewBaseFeeOverhead)
+			log.Info("Updated L2 base fee overhead", "blockNumber", l.BlockNumber, "blockHash", l.BlockHash.Hex(), "old", event.OldBaseFeeOverhead, "new", event.NewBaseFeeOverhead)
+		case l2_system_config.BaseFeeScalarUpdatedTopic:
+			event, err := l2_system_config.UnpackBaseFeeScalarUpdatedEvent(*l)
+			if err != nil {
+				log.Error("failed to unpack base fee scalar updated event log", "err", err, "log", *l)
+				break // break from switch, continue loop
+			}
+			misc.UpdateL2BaseFeeScalar(event.NewBaseFeeScalar)
+			log.Info("Updated L2 base fee scalar", "blockNumber", l.BlockNumber, "blockHash", l.BlockHash.Hex(), "old", event.OldBaseFeeScalar, "new", event.NewBaseFeeScalar)
+		}
+	}
+}
+
 // BlockChain represents the canonical chain given a database with a genesis
 // block. The Blockchain manages chain imports, reverts, chain reorganisations.
 //
@@ -1272,6 +1308,9 @@ func (bc *BlockChain) writeBlockWithState(block *types.Block, receipts []*types.
 	// Note the latest relayed L1 message queue index (if any)
 	updateHeadL1msgGauge(block)
 
+	// Execute L2 base fee coefficient updates (if any)
+	updateL2BaseFeeCoefficients(bc.Config().Scroll.L2SystemConfigAddress(), logs)
+
 	parent := bc.GetHeaderByHash(block.ParentHash())
 	// block.Time is guaranteed to be larger than parent.Time,
 	// and the time gap should fit into int64.
@@ -1302,7 +1341,7 @@ func (bc *BlockChain) writeBlockWithState(block *types.Block, receipts []*types.
 	if queueIndex == nil {
 		// We expect that we only insert contiguous chain segments,
 		// so the parent will always be inserted first.
-		log.Crit("Queue index in DB is nil", "parent", block.ParentHash(), "hash", block.Hash())
+		log.Crit("Queue index in DB is nil", "parent", block.ParentHash().Hex(), "hash", block.Hash().Hex())
 	}
 	numProcessed := uint64(block.NumL1MessagesProcessed(*queueIndex))
 	// do not overwrite the index written by the miner worker