feat(fd): support Bedrock networks

Updates the fault detector to support Bedrock networks. Bedrock support
is slightly hacky because we still also need to support the legacy
system until mainnet has been upgraded to Bedrock. We will want to
update the fault detector again once mainnet is upgraded to simplify the
service and remove the legacy components.

.changeset/nervous-years-explain.md

+---
+'@eth-optimism/fault-detector': minor
+---
+
+Updates the fault detector to support Bedrock networks.

packages/data-transport-layer/.depcheckrc

 ignores: [
   "@babel/eslint-parser",
+  "@types/level",
   "@typescript-eslint/parser",
   "eslint-plugin-import",
   "eslint-plugin-unicorn",

packages/data-transport-layer/package.json

@@ -52,7 +52,7 @@
     "ethers": "^5.7.0",
     "express": "^4.17.1",
     "express-prom-bundle": "^6.3.6",
-    "level": "^6.0.1",
+    "level6": "npm:level@^6.0.1",
     "levelup": "^4.4.0"
   },
   "devDependencies": {

packages/data-transport-layer/src/services/main/service.ts

 /* Imports: External */
 import { BaseService, LegacyMetrics } from '@eth-optimism/common-ts'
 import { LevelUp } from 'levelup'
-import level from 'level'
+import level from 'level6'
 import { Counter } from 'prom-client'
 
 /* Imports: Internal */

packages/fault-detector/src/helpers.ts

-import { Contract } from 'ethers'
+import { Contract, BigNumber } from 'ethers'
+
+export interface OutputOracle<TSubmissionEventArgs> {
+  contract: Contract
+  filter: any
+  getTotalElements: () => Promise<BigNumber>
+  getEventIndex: (args: TSubmissionEventArgs) => BigNumber
+}
 
 /**
  * Partial event interface, meant to reduce the size of the event cache to avoid
@@ -41,27 +48,32 @@ const getCache = (
 }
 
 /**
- * Updates the event cache for the SCC.
+ * Updates the event cache for a contract and event.
  *
- * @param scc The State Commitment Chain contract.
+ * @param contract Contract to update cache for.
+ * @param filter Event filter to use.
  */
-export const updateStateBatchEventCache = async (
-  scc: Contract
+export const updateOracleCache = async <TSubmissionEventArgs>(
+  oracle: OutputOracle<TSubmissionEventArgs>
 ): Promise<void> => {
-  const cache = getCache(scc.address)
+  const cache = getCache(oracle.contract.address)
   let currentBlock = cache.highestBlock
-  const endingBlock = await scc.provider.getBlockNumber()
+  const endingBlock = await oracle.contract.provider.getBlockNumber()
   let step = endingBlock - currentBlock
   let failures = 0
   while (currentBlock < endingBlock) {
     try {
-      const events = await scc.queryFilter(
-        scc.filters.StateBatchAppended(),
+      const events = await oracle.contract.queryFilter(
+        oracle.filter,
         currentBlock,
         currentBlock + step
       )
+
+      // Throw the events into the cache.
       for (const event of events) {
-        cache.eventCache[event.args._batchIndex.toNumber()] = {
+        cache.eventCache[
+          oracle.getEventIndex(event.args as TSubmissionEventArgs).toNumber()
+        ] = {
           blockNumber: event.blockNumber,
           transactionHash: event.transactionHash,
           args: event.args,
@@ -97,15 +109,15 @@ export const updateStateBatchEventCache = async (
 /**
  * Finds the Event that corresponds to a given state batch by index.
  *
- * @param scc StateCommitmentChain contract.
+ * @param oracle Output oracle contract
  * @param index State batch index to search for.
  * @returns Event corresponding to the batch.
  */
-export const findEventForStateBatch = async (
-  scc: Contract,
+export const findEventForStateBatch = async <TSubmissionEventArgs>(
+  oracle: OutputOracle<TSubmissionEventArgs>,
   index: number
 ): Promise<PartialEvent> => {
-  const cache = getCache(scc.address)
+  const cache = getCache(oracle.contract.address)
 
   // Try to find the event in cache first.
   if (cache.eventCache[index]) {
@@ -113,7 +125,7 @@ export const findEventForStateBatch = async (
   }
 
   // Update the event cache if we don't have the event.
-  await updateStateBatchEventCache(scc)
+  await updateOracleCache(oracle)
 
   // Event better be in cache now!
   if (cache.eventCache[index] === undefined) {
@@ -126,23 +138,23 @@ export const findEventForStateBatch = async (
 /**
  * Finds the first state batch index that has not yet passed the fault proof window.
  *
- * @param scc StateCommitmentChain contract.
+ * @param oracle Output oracle contract.
  * @returns Starting state root batch index.
  */
-export const findFirstUnfinalizedStateBatchIndex = async (
-  scc: Contract
+export const findFirstUnfinalizedStateBatchIndex = async <TSubmissionEventArgs>(
+  oracle: OutputOracle<TSubmissionEventArgs>,
+  fpw: number
 ): Promise<number> => {
-  const fpw = (await scc.FRAUD_PROOF_WINDOW()).toNumber()
-  const latestBlock = await scc.provider.getBlock('latest')
-  const totalBatches = (await scc.getTotalBatches()).toNumber()
+  const latestBlock = await oracle.contract.provider.getBlock('latest')
+  const totalBatches = (await oracle.getTotalElements()).toNumber()
 
   // Perform a binary search to find the next batch that will pass the challenge period.
   let lo = 0
   let hi = totalBatches
   while (lo !== hi) {
     const mid = Math.floor((lo + hi) / 2)
-    const event = await findEventForStateBatch(scc, mid)
-    const block = await scc.provider.getBlock(event.blockNumber)
+    const event = await findEventForStateBatch(oracle, mid)
+    const block = await oracle.contract.provider.getBlock(event.blockNumber)
 
     if (block.timestamp + fpw < latestBlock.timestamp) {
       lo = mid + 1

packages/fault-detector/test/helpers.spec.ts

@@ -12,6 +12,7 @@ import { expect } from './setup'
 import {
   findEventForStateBatch,
   findFirstUnfinalizedStateBatchIndex,
+  OutputOracle,
 } from '../src'
 
 describe('helpers', () => {
@@ -28,6 +29,7 @@ describe('helpers', () => {
   let AddressManager: Contract
   let ChainStorageContainer: Contract
   let StateCommitmentChain: Contract
+  let oracle: OutputOracle<any>
   beforeEach(async () => {
     // Set up fakes
     FakeBondManager = await smock.fake(getContractInterface('BondManager'))
@@ -67,6 +69,13 @@ describe('helpers', () => {
     // Set up mock returns
     FakeCanonicalTransactionChain.getTotalElements.returns(1000000000) // just needs to be large
     FakeBondManager.isCollateralized.returns(true)
+
+    oracle = {
+      contract: StateCommitmentChain,
+      filter: StateCommitmentChain.filters.StateBatchAppended(),
+      getTotalElements: async () => StateCommitmentChain.getTotalBatches(),
+      getEventIndex: (args: any) => args._batchIndex,
+    }
   })
 
   describe('findEventForStateBatch', () => {
@@ -79,7 +88,7 @@ describe('helpers', () => {
       })
 
       it('should return the event', async () => {
-        const event = await findEventForStateBatch(StateCommitmentChain, 0)
+        const event = await findEventForStateBatch(oracle, 0)
 
         expect(event.args._batchIndex).to.equal(0)
       })
@@ -88,7 +97,7 @@ describe('helpers', () => {
     describe('when the event does not exist', () => {
       it('should throw an error', async () => {
         await expect(
-          findEventForStateBatch(StateCommitmentChain, 0)
+          findEventForStateBatch(oracle, 0)
         ).to.eventually.be.rejectedWith('unable to find event for batch')
       })
     })
@@ -119,7 +128,8 @@ describe('helpers', () => {
 
       it('should find the first batch older than the FPW', async () => {
         const first = await findFirstUnfinalizedStateBatchIndex(
-          StateCommitmentChain
+          oracle,
+          challengeWindowSeconds
         )
 
         expect(first).to.equal(1)
@@ -144,7 +154,8 @@ describe('helpers', () => {
 
       it('should return zero', async () => {
         const first = await findFirstUnfinalizedStateBatchIndex(
-          StateCommitmentChain
+          oracle,
+          challengeWindowSeconds
         )
 
         expect(first).to.equal(0)
@@ -177,7 +188,8 @@ describe('helpers', () => {
 
       it('should return undefined', async () => {
         const first = await findFirstUnfinalizedStateBatchIndex(
-          StateCommitmentChain
+          oracle,
+          challengeWindowSeconds
         )
 
         expect(first).to.equal(undefined)

yarn.lock

@@ -12090,7 +12090,7 @@ level-ws@^2.0.0:
     readable-stream "^3.1.0"
     xtend "^4.0.1"
 
-level@^6.0.1:
+"level6@npm:level@^6.0.1":
   version "6.0.1"
   resolved "https://registry.yarnpkg.com/level/-/level-6.0.1.tgz#dc34c5edb81846a6de5079eac15706334b0d7cd6"
   integrity sha512-psRSqJZCsC/irNhfHzrVZbmPYXDcEYhA5TVNwr+V92jF44rbf86hqGp8fiT702FyiArScYIlPSBTDUASCVNSpw==