Change handling of fetching events to reduce RPC calls (especially on L2's)

src/contracts/railgun-smart-wallet/V2/__tests__/railgun-smart-wallet.test.ts

@@ -188,21 +188,6 @@ describe('railgun-smart-wallet', function runTests() {
     };
   });
 
-  it('Should fail to instantiate without a polling provider', () => {
-    const nonPollingProvider = new JsonRpcProvider(config.rpc);
-    expect(() => {
-      // eslint-disable-next-line @typescript-eslint/no-unsafe-argument, @typescript-eslint/no-explicit-any
-      return new RailgunSmartWalletContract(
-        'abc',
-        nonPollingProvider as any,
-        nonPollingProvider as any,
-        chain,
-      );
-    }).to.throw(
-      'The JsonRpcProvider must have polling enabled. Use PollingJsonRpcProvider to instantiate.',
-    );
-  });
-
   it('[HH] Should retrieve merkle root from contract', async function run() {
     if (!isDefined(process.env.RUN_HARDHAT_TESTS)) {
       this.skip();

src/contracts/railgun-smart-wallet/V2/railgun-smart-wallet.ts

@@ -2,8 +2,9 @@ import {
   Contract,
   ContractEventPayload,
   ContractTransaction,
-  FallbackProvider,
   Interface,
+  JsonRpcApiProvider,
+  Provider,
   Result,
 } from 'ethers';
 import EventEmitter from 'events';
@@ -62,8 +63,6 @@ const SCAN_TIMEOUT_ERROR_MESSAGE = 'getLogs request timed out after 5 seconds.';
 export class RailgunSmartWalletContract extends EventEmitter {
   readonly contract: RailgunSmartWallet;
 
-  readonly contractForListeners: RailgunSmartWallet;
-
   readonly address: string;
 
   readonly chain: Chain;
@@ -73,12 +72,18 @@ export class RailgunSmartWalletContract extends EventEmitter {
   /**
    * Connect to Railgun instance on network
    * @param railgunSmartWalletContractAddress - address of Railgun instance (Proxy contract)
-   * @param provider - Network provider
+   * @param defaultProvider - Network provider
+   * @param pollingProvider - DEPRECATED
+   * @param chain
    */
   constructor(
     railgunSmartWalletContractAddress: string,
-    defaultProvider: PollingJsonRpcProvider | FallbackProvider,
-    pollingProvider: PollingJsonRpcProvider,
+    defaultProvider: Provider,
+    /**
+      * @deprecated pollingProvider will be removed in the next major version.
+    */
+    pollingProvider?: Provider,
+    // @ts-ignore - Ignore optional param last requirement during deprecation
     chain: Chain,
   ) {
     super();
@@ -89,15 +94,6 @@ export class RailgunSmartWalletContract extends EventEmitter {
       defaultProvider,
     ) as unknown as RailgunSmartWallet;
 
-    // Because of a 'stallTimeout' bug in Ethers v6, all providers in a FallbackProvider will get called simultaneously.
-    // So, we'll use a single json rpc (the first in the FallbackProvider) to poll for the event listeners.
-    assertIsPollingProvider(pollingProvider);
-    this.contractForListeners = new Contract(
-      railgunSmartWalletContractAddress,
-      ABIRailgunSmartWallet,
-      pollingProvider,
-    ) as unknown as RailgunSmartWallet;
-
     this.chain = chain;
   }
 
@@ -290,7 +286,7 @@ export class RailgunSmartWalletContract extends EventEmitter {
     const transactTopic = this.contract.getEvent('Transact').getFragment().topicHash;
     const unshieldTopic = this.contract.getEvent('Unshield').getFragment().topicHash;
 
-    await this.contractForListeners.on(
+    await this.contract.on(
       // @ts-expect-error - Use * to request all events
       '*', // All Events
       (event: ContractEventPayload) => {
@@ -633,6 +629,5 @@ export class RailgunSmartWalletContract extends EventEmitter {
    */
   async unload() {
     await this.contract.removeAllListeners();
-    await this.contractForListeners?.removeAllListeners();
   }
 }

src/contracts/railgun-smart-wallet/V3/poseidon-merkle-accumulator.ts

@@ -1,12 +1,10 @@
-import { Contract, ContractEventPayload, FallbackProvider, Result } from 'ethers';
+import { Contract, ContractEventPayload, Provider, Result } from 'ethers';
 import EventEmitter from 'events';
 import { Chain } from '../../../models/engine-types';
-import { PollingJsonRpcProvider } from '../../../provider/polling-json-rpc-provider';
 import { PoseidonMerkleAccumulator } from '../../../abi/typechain/PoseidonMerkleAccumulator';
 import { ABIPoseidonMerkleAccumulator } from '../../../abi/abi';
 import { ByteLength, ByteUtils } from '../../../utils/bytes';
 import EngineDebug from '../../../debugger/debugger';
-import { assertIsPollingProvider } from '../../../provider/polling-util';
 import {
   EngineEvent,
   EventsCommitmentListener,
@@ -29,8 +27,6 @@ const SCAN_TIMEOUT_ERROR_MESSAGE = 'getLogs request timed out after 5 seconds.';
 export class PoseidonMerkleAccumulatorContract extends EventEmitter {
   readonly contract: PoseidonMerkleAccumulator;
 
-  readonly contractForListeners: PoseidonMerkleAccumulator;
-
   readonly address: string;
 
   readonly chain: Chain;
@@ -39,10 +35,20 @@ export class PoseidonMerkleAccumulatorContract extends EventEmitter {
 
   private readonly eventTopic: string;
 
+  /**
+   * @param address 
+   * @param provider 
+   * @param pollingProvider - DEPRECATED
+   * @param chain 
+   */
   constructor(
     address: string,
-    provider: PollingJsonRpcProvider | FallbackProvider,
-    pollingProvider: PollingJsonRpcProvider,
+    provider: Provider,
+    /**
+      * @deprecated pollingProvider will be removed in the next major version.
+    */
+    pollingProvider?: Provider,
+    // @ts-ignore - Ignore optional param last requirement during deprecation
     chain: Chain,
   ) {
     super();
@@ -54,15 +60,6 @@ export class PoseidonMerkleAccumulatorContract extends EventEmitter {
     ) as unknown as PoseidonMerkleAccumulator;
     this.eventTopic = this.contract.getEvent('AccumulatorStateUpdate').getFragment().topicHash;
     this.chain = chain;
-
-    // Because of a 'stallTimeout' bug in Ethers v6, all providers in a FallbackProvider will get called simultaneously.
-    // So, we'll use a single json rpc (the first in the FallbackProvider) to poll for the event listeners.
-    assertIsPollingProvider(pollingProvider);
-    this.contractForListeners = new Contract(
-      address,
-      ABIPoseidonMerkleAccumulator,
-      pollingProvider,
-    ) as unknown as PoseidonMerkleAccumulator;
   }
 
   /**
@@ -104,7 +101,7 @@ export class PoseidonMerkleAccumulatorContract extends EventEmitter {
     eventsRailgunTransactionsV3Listener: EventsRailgunTransactionListenerV3,
     triggerWalletBalanceDecryptions: (txidVersion: TXIDVersion) => Promise<void>,
   ): Promise<void> {
-    await this.contractForListeners.on(this.eventTopic as any, (event: ContractEventPayload) => {
+    await this.contract.on(this.eventTopic as any, (event: ContractEventPayload) => {
       try {
         if (event.log.topics.length !== 1) {
           throw new Error('Requires one topic for railgun events');
@@ -264,6 +261,5 @@ export class PoseidonMerkleAccumulatorContract extends EventEmitter {
    */
   async unload() {
     await this.contract.removeAllListeners();
-    await this.contractForListeners?.removeAllListeners();
   }
 }

src/contracts/railgun-smart-wallet/V3/poseidon-merkle-verifier.ts

@@ -1,5 +1,4 @@
-import { Contract, ContractTransaction, FallbackProvider } from 'ethers';
-import { PollingJsonRpcProvider } from '../../../provider/polling-json-rpc-provider';
+import { Contract, ContractTransaction, Provider } from 'ethers';
 import { PoseidonMerkleVerifier } from '../../../abi/typechain/PoseidonMerkleVerifier';
 import { ABIPoseidonMerkleVerifier } from '../../../abi/abi';
 import { ShieldCiphertextStruct } from '../../../abi/typechain/RailgunSmartWallet';
@@ -9,7 +8,7 @@ export class PoseidonMerkleVerifierContract {
 
   readonly address: string;
 
-  constructor(address: string, provider: PollingJsonRpcProvider | FallbackProvider) {
+  constructor(address: string, provider: Provider) {
     this.address = address;
     this.contract = new Contract(
       address,

src/contracts/railgun-smart-wallet/V3/token-vault-contract.ts

@@ -1,6 +1,5 @@
-import { Contract, FallbackProvider } from 'ethers';
+import { Contract, Provider } from 'ethers';
 import { TokenDataStructOutput, TokenVault } from '../../../abi/typechain/TokenVault';
-import { PollingJsonRpcProvider } from '../../../provider/polling-json-rpc-provider';
 import { ABITokenVault } from '../../../abi/abi';
 import { ByteLength, ByteUtils } from '../../../utils/bytes';
 import EngineDebug from '../../../debugger/debugger';
@@ -10,7 +9,7 @@ export class TokenVaultContract {
 
   readonly address: string;
 
-  constructor(address: string, provider: PollingJsonRpcProvider | FallbackProvider) {
+  constructor(address: string, provider: Provider) {
     this.address = address;
     this.contract = new Contract(address, ABITokenVault, provider) as unknown as TokenVault;
   }

src/railgun-engine.ts

@@ -1,6 +1,6 @@
 import type { AbstractLevelDOWN } from 'abstract-leveldown';
 import EventEmitter from 'events';
-import { FallbackProvider } from 'ethers';
+import type { JsonRpcApiProvider, Provider } from 'ethers';
 import { RailgunSmartWalletContract } from './contracts/railgun-smart-wallet/V2/railgun-smart-wallet';
 import { RelayAdaptV2Contract } from './contracts/relay-adapt/V2/relay-adapt-v2';
 import { Database, DatabaseNamespace } from './database/database';
@@ -46,8 +46,6 @@ import {
   CURRENT_TXID_V2_MERKLETREE_HISTORY_VERSION,
   CURRENT_UTXO_MERKLETREE_HISTORY_VERSION,
 } from './utils/constants';
-import { PollingJsonRpcProvider } from './provider/polling-json-rpc-provider';
-import { assertIsPollingProvider } from './provider/polling-util';
 import { isDefined } from './utils/is-defined';
 import { UTXOMerkletree } from './merkletree/utxo-merkletree';
 import { TXIDMerkletree } from './merkletree/txid-merkletree';
@@ -1445,20 +1443,31 @@ class RailgunEngine extends EventEmitter {
 
   /**
    * Load network
+   * @param chain
    * @param railgunSmartWalletContractAddress - address of railgun instance (proxy contract)
    * @param relayAdaptV2ContractAddress - address of railgun instance (proxy contract)
-   * @param provider - ethers provider for network
-   * @param deploymentBlock - block number to start scanning from
-   */
+   * @param poseidonMerkleAccumulatorV3Address
+   * @param poseidonMerkleVerifierV3Address
+   * @param tokenVaultV3Address
+   * @param defaultProvider - ethers provider for network
+   * @param pollingProvider - DEPRECATED
+   * @param deploymentBlocks - block number to start scanning from
+   * @param poiLaunchBlock
+   * @param supportsV3 
+  */
   async loadNetwork(
     chain: Chain,
     railgunSmartWalletContractAddress: string,
     relayAdaptV2ContractAddress: string,
     poseidonMerkleAccumulatorV3Address: string,
     poseidonMerkleVerifierV3Address: string,
     tokenVaultV3Address: string,
-    defaultProvider: PollingJsonRpcProvider | FallbackProvider,
-    pollingProvider: PollingJsonRpcProvider,
+    defaultProvider: Provider,
+    /**
+      * @deprecated pollingProvider will be removed in the next major version.
+    */
+    pollingProvider?: Provider,
+    // @ts-ignore - Ignore optional param last requirement during deprecation
     deploymentBlocks: Record<TXIDVersion, number>,
     poiLaunchBlock: Optional<number>,
     supportsV3: boolean,
@@ -1480,24 +1489,6 @@ class RailgunEngine extends EventEmitter {
       throw err;
     }
 
-    assertIsPollingProvider(pollingProvider);
-    try {
-      await promiseTimeout(
-        pollingProvider.getBlockNumber(),
-        60_000,
-        'Timed out waiting for polling RPC provider to connect.',
-      );
-    } catch (cause) {
-      const err = new Error(
-        'Failed to get block number from polling provider when loading network',
-        {
-          cause,
-        },
-      );
-      EngineDebug.error(cause as Error);
-      throw err;
-    }
-
     if (supportsV3) {
       addChainSupportsV3(chain);
     }

src/test/helper.test.ts

@@ -138,7 +138,7 @@ export const awaitRailgunSmartWalletEvent = async (
     new Promise<void>((resolve) => {
       // eslint-disable-next-line @typescript-eslint/no-floating-promises
       // @ts-expect-error
-      RailgunVersionedSmartContracts.getAccumulator(txidVersion, chain).contractForListeners.once(
+      RailgunVersionedSmartContracts.getAccumulator(txidVersion, chain).contract.once(
         event,
         () => resolve(),
       );