Improve OP fee estimation

zp-relayer/services/fee/DynamicFeeManager.ts

@@ -25,6 +25,11 @@ export class DynamicFeeManager extends FeeManager {
   async _fetchFeeOptions(): Promise<DynamicFeeOptions> {
     const gasPrice = await this.gasPrice.fetchOnce()
     const oneByteFee = FeeManager.executionFee(gasPrice, toBN(NZERO_BYTE_GAS))
-    return DynamicFeeOptions.fromGasPice(gasPrice, oneByteFee, relayerConfig.minBaseFee)
+    return DynamicFeeOptions.fromParams({
+      gasPrice,
+      oneByteFee,
+      minFee: relayerConfig.minBaseFee,
+      baseExtra: toBN(0),
+    })
   }
 }

zp-relayer/services/fee/FeeManager.ts

@@ -93,10 +93,18 @@ type DynamicFeeKeys = [
   'oneByteFee',
   'nativeConvertFee'
 ]
+
+interface DynamicFeeParams {
+  gasPrice: GasPriceValue
+  oneByteFee: BN
+  minFee: BN
+  baseExtra: BN
+}
+
 // Utility class for dynamic fee estimations
 export class DynamicFeeOptions extends FeeOptions<DynamicFeeKeys> {
-  static fromGasPice(gasPrice: GasPriceValue, oneByteFee: BN, minFee: BN) {
-    const getFee = (txType: TxType) => FeeManager.executionFee(gasPrice, config.baseTxGas[txType])
+  static fromParams({ gasPrice, baseExtra, oneByteFee, minFee }: DynamicFeeParams) {
+    const getFee = (txType: TxType) => FeeManager.executionFee(gasPrice, config.baseTxGas[txType]).add(baseExtra)
     const fees: Fees<DynamicFeeKeys> = {
       [TxType.DEPOSIT]: getFee(TxType.DEPOSIT),
       [TxType.PERMITTABLE_DEPOSIT]: getFee(TxType.PERMITTABLE_DEPOSIT),

zp-relayer/services/fee/OptimismFeeManager.ts

@@ -10,8 +10,12 @@ import relayerConfig from '@/configs/relayerConfig'
 import { ZERO_BYTE_GAS, NZERO_BYTE_GAS } from '@/utils/constants'
 import type { EstimationType, GasPrice } from '../gas-price'
 
+// Rough estimation of tx RLP encoding overhead in bytes
+const RLP_ENCODING_OVERHEAD = toBN(120)
+const SIGNATURE_GAS = toBN(68 * 16)
+
 export class OptimismFeeManager extends FeeManager {
-  private oracle: Contract
+  public oracle: Contract
   private overhead!: BN
   private decimals!: BN
   private scalar!: BN
@@ -27,16 +31,21 @@ export class OptimismFeeManager extends FeeManager {
     this.scalar = await contractCallRetry(this.oracle, 'scalar').then(toBN)
   }
 
-  private getL1GasUsed(data: string): BN {
+  private getL1GasUsed(data: string, includeOverhead: boolean): BN {
     const byteToGas = (byte: number) => (byte === 0 ? ZERO_BYTE_GAS : NZERO_BYTE_GAS)
     const bytes = hexToBytes(data)
-    const l1GasUsed = bytes.reduce((acc, byte) => acc + byteToGas(byte), 0)
-    return toBN(l1GasUsed).add(this.overhead)
+    const total = bytes.reduce((acc, byte) => acc + byteToGas(byte), 0)
+    const unsigned = toBN(total)
+    if (includeOverhead) {
+      const totalOverhead = this.overhead.add(SIGNATURE_GAS).add(RLP_ENCODING_OVERHEAD)
+      unsigned.iadd(totalOverhead)
+    }
+    return unsigned
   }
 
   // Mimics OP gas price oracle algorithm
-  private getL1Fee(data: string, l1BaseFee: BN): BN {
-    const l1GasUsed = this.getL1GasUsed(data)
+  private getL1Fee(data: string, l1BaseFee: BN, includeOverhead: boolean): BN {
+    const l1GasUsed = this.getL1GasUsed(data, includeOverhead)
     const l1Fee = l1GasUsed.mul(l1BaseFee)
     const divisor = toBN(10).pow(this.decimals)
     const unscaled = l1Fee.mul(this.scalar)
@@ -46,14 +55,9 @@ export class OptimismFeeManager extends FeeManager {
 
   async _estimateFee({ txType, nativeConvert, txData }: IFeeEstimateParams, feeOptions: DynamicFeeOptions) {
     const { [txType]: baseFee, nativeConvertFee, oneByteFee } = feeOptions.fees
-
-    const unscaledL1Fee = this.getL1Fee(txData, oneByteFee)
-
-    // Because oneByteFee = l1BaseFee * NZERO_BYTE_GAS, we need to divide the estimation
-    // We do it here to get a more accurate result
-    const l1Fee = unscaledL1Fee.divn(NZERO_BYTE_GAS)
-
-    const fee = baseFee.add(l1Fee)
+    // -1 to account for the 0x prefix
+    const calldataLen = (txData.length >> 1) - 1
+    const fee = baseFee.add(oneByteFee.muln(calldataLen))
     if (nativeConvert) {
       fee.iadd(nativeConvertFee)
     }
@@ -65,8 +69,14 @@ export class OptimismFeeManager extends FeeManager {
 
     const l1BaseFee = await contractCallRetry(this.oracle, 'l1BaseFee').then(toBN)
 
-    const oneByteFee = l1BaseFee.muln(NZERO_BYTE_GAS)
+    const oneByteFee = this.getL1Fee('0xff', l1BaseFee, false)
+    const baseExtra = this.getL1Fee('0x', l1BaseFee, true)
 
-    return DynamicFeeOptions.fromGasPice(gasPrice, oneByteFee, relayerConfig.minBaseFee)
+    return DynamicFeeOptions.fromParams({
+      gasPrice,
+      oneByteFee,
+      minFee: relayerConfig.minBaseFee,
+      baseExtra,
+    })
   }
 }

zp-relayer/test.env

@@ -21,3 +21,4 @@ RELAYER_SENT_TX_DELAY=2000
 RELAYER_GAS_PRICE_FALLBACK=
 RELAYER_GAS_PRICE_UPDATE_INTERVAL=100000
 RELAYER_GAS_PRICE_ESTIMATION_TYPE="eip1559-gas-estimation"
+RELAYER_FEE_MANAGER_TYPE=static

zp-relayer/test/worker-tests/poolWorker.test.ts

@@ -38,7 +38,8 @@ import flowZeroAddressWithdraw from '../flows/flow_zero-address_withdraw_2.json'
 import { Params } from 'libzkbob-rs-node'
 import { directDepositQueue } from '../../queue/directDepositQueue'
 import { createDirectDepositWorker } from '../../workers/directDepositWorker'
-import { DynamicFeeManager, FeeManager } from '../../services/fee'
+import { FeeManager, StaticFeeManager } from '../../services/fee'
+import { NativePriceFeed } from '../../services/price-feed'
 
 chai.use(chaiAsPromised)
 const expect = chai.expect
@@ -96,18 +97,16 @@ describe('poolWorker', () => {
     gasPriceService = new GasPrice(web3, { gasPrice: config.gasPriceFallback }, 10000, EstimationType.Web3, {})
     await gasPriceService.start()
 
-    const mockPriceFeed = {
-      convert: (amounts: BN[]) => Promise.resolve(amounts.map(() => toBN(0))),
-    }
+    const mockPriceFeed = new NativePriceFeed()
     const managerConfig = {
       gasPrice: gasPriceService,
       priceFeed: mockPriceFeed,
-      scaleFactor: toBN(1),
-      marginFactor: toBN(1),
+      scaleFactor: toBN(100),
+      marginFactor: toBN(100),
       updateInterval: config.feeManagerUpdateInterval,
       defaultFeeOptionsParams: { gasLimit: config.relayerGasLimit },
     }
-    feeManager = new DynamicFeeManager(managerConfig, gasPriceService)
+    feeManager = new StaticFeeManager(managerConfig, toBN(0))
     await feeManager.start()
 
     txManager = new TxManager(web3, config.relayerPrivateKey, gasPriceService)

zp-relayer/utils/constants.ts

@@ -1,7 +1,6 @@
 import { Constants } from 'libzkbob-rs-node'
 
 const BASE_CALLDATA_SIZE = 644 // constant calldata size for tx without memo
-const RAW_TX_RLP_OVERHEAD = 110
 
 const constants = {
   FALLBACK_RPC_URL_SWITCH_TIMEOUT: 60 * 60 * 1000,
@@ -19,7 +18,7 @@ const constants = {
   ZERO_ADDRESS: '0x0000000000000000000000000000000000000000',
   PERMIT2_CONTRACT: '0x000000000022D473030F116dDEE9F6B43aC78BA3',
   INIT_ROOT: '11469701942666298368112882412133877458305516134926649826543144744382391691533',
-  MOCK_CALLDATA: '0x' + 'ff'.repeat(BASE_CALLDATA_SIZE + RAW_TX_RLP_OVERHEAD),
+  MOCK_CALLDATA: '0x' + 'ff'.repeat(BASE_CALLDATA_SIZE),
   ZERO_BYTE_GAS: 4,
   NZERO_BYTE_GAS: 16,
   OP_GAS_ORACLE_ADDRESS: '0x420000000000000000000000000000000000000F',

zp-relayer/utils/helpers.ts

@@ -250,7 +250,5 @@ export function getFileHash(path: string) {
 }
 
 export function applyDenominator(n: BN, d: BN) {
-  return d.testn(255)
-    ? n.div(d.maskn(255))
-    : n.mul(d)
+  return d.testn(255) ? n.div(d.maskn(255)) : n.mul(d)
 }