chore: cache chainInfo in embeddedwallet (#22592)

A wallet is instantiated for a particular chain, and if an app supports
multiple it is expected to recreate the whole thing. We are calling
`getChainInfo` a surprising amount of times, so it makes sense to cache
it for performance.

---------

Co-authored-by: benesjan <janbenes1234@gmail.com>

Author: 2 people

yarn-project/wallet-sdk/src/base-wallet/base_wallet.ts

@@ -43,6 +43,7 @@ import type { AuthWitness } from '@aztec/stdlib/auth-witness';
 import { AztecAddress } from '@aztec/stdlib/aztec-address';
 import {
   type ContractInstanceWithAddress,
+  type NodeInfo,
   computePartialAddress,
   getContractClassFromArtifact,
 } from '@aztec/stdlib/contract';
@@ -107,6 +108,9 @@ export type CompleteFeeOptionsConfig = {
 export abstract class BaseWallet implements Wallet {
   protected minFeePadding = 0.5;
   protected cancellableTransactions = false;
+  // A wallet is instantiated for a particular chain, so chain info never changes during its lifetime.
+  // We cache it here because getChainInfo is called frequently (every tx simulation, send, auth wit, etc.).
+  private nodeInfoPromise: Promise<NodeInfo> | undefined;
 
   // Protected because we want to force wallets to instantiate their own PXE.
   protected constructor(
@@ -138,7 +142,10 @@ export abstract class BaseWallet implements Wallet {
   }
 
   async getChainInfo(): Promise<ChainInfo> {
-    const { l1ChainId, rollupVersion } = await this.aztecNode.getNodeInfo();
+    if (!this.nodeInfoPromise) {
+      this.nodeInfoPromise = this.aztecNode.getNodeInfo();
+    }
+    const { l1ChainId, rollupVersion } = await this.nodeInfoPromise;
     return { chainId: new Fr(l1ChainId), version: new Fr(rollupVersion) };
   }