refactor: cache erc20 token decimals

src/BroSDK.ts

@@ -316,6 +316,9 @@ export class BroSDK {
       evm: {
         routesConfigCache: new Map(),
         feeRateCache: new Map(),
+        tokenInfoCaches: {
+          decimals: new Map(),
+        },
         onChainConfigCache,
         viemClients: {
           ...defaultEvmClients,

src/evmUtils/contractHelpers.ts

@@ -11,6 +11,8 @@ import { nativeCurrencyAddress } from "./addressHelpers"
 import { getEVMOnChainConfig } from "./apiHelpers/getEVMOnChainConfig"
 import { getEVMSupportedRoutes } from "./apiHelpers/getEVMSupportedRoutes"
 import { EVMEndpointContract } from "./evmContractAddresses"
+import { readContract } from "viem/actions"
+import { ERC20Abi } from "./contractAbi/ERC20Abi"
 
 const CONTRACT_COMMON_NUMBER_SCALE = 18
 export const numberFromSolidityContractNumber = (
@@ -113,3 +115,35 @@ export async function getEVMToken(
     r => r.evmTokenAddress.toLowerCase() === tokenAddress.toLowerCase(),
   )?.evmToken
 }
+
+export function getERC20TokenDecimals(
+  sdkContext: SDKGlobalContext,
+  chainId: KnownChainId.EVMChain,
+  tokenAddress: EVMAddress,
+): Promise<undefined | number> {
+  const cacheKey = `${chainId}:${tokenAddress}`
+
+  const tokenInfoCache = sdkContext.evm.tokenInfoCaches.decimals.get(cacheKey)
+  if (tokenInfoCache != null) return tokenInfoCache
+
+  const client = sdkContext.evm.viemClients[chainId]
+  if (client == null) return Promise.resolve(undefined)
+
+  const resPromise = readContract(client, {
+    abi: ERC20Abi,
+    address: tokenAddress,
+    functionName: "decimals",
+  }).catch(err => {
+    queueMicrotask(() => {
+      if (
+        sdkContext.evm.tokenInfoCaches.decimals.get(cacheKey) === resPromise
+      ) {
+        sdkContext.evm.tokenInfoCaches.decimals.delete(cacheKey)
+      }
+    })
+    throw err
+  })
+  sdkContext.evm.tokenInfoCaches.decimals.set(cacheKey, resPromise)
+
+  return resPromise
+}

src/sdkUtils/types.internal.ts

@@ -83,6 +83,9 @@ export interface SDKGlobalContext {
       string,
       Promise<undefined | TransferProphet>
     >
+    tokenInfoCaches: {
+      decimals: SDKGlobalContextCache<string, Promise<undefined | number>>
+    }
     routesConfigCache?: SDKGlobalContextCache<
       "mainnet" | "testnet",
       Promise<EVMSupportedRoute[]>

src/utils/swapHelpers/fetchDexAggregatorPossibleRoutes/helpers.ts

@@ -1,6 +1,9 @@
 import { readContract } from "viem/actions"
 import { ERC20Abi } from "../../../evmUtils/contractAbi/ERC20Abi"
-import { getEVMTokenContractInfo } from "../../../evmUtils/contractHelpers"
+import {
+  getERC20TokenDecimals,
+  getEVMTokenContractInfo,
+} from "../../../evmUtils/contractHelpers"
 import { evmChainIdFromKnownChainId } from "../../../evmUtils/evmClients"
 import {
   EVMAddress,
@@ -68,23 +71,19 @@ export async function getQueryableRoutes(
     return
   }
 
-  const client = Object.values(sdkContext.evm.viemClients).find(
-    c => c.chain?.id === Number(chainId),
-  )
-  if (client == null) return
-
   const [fromTokenDecimals, toTokenDecimals] = await Promise.all([
-    readContract(client, {
-      abi: ERC20Abi,
-      address: fromEVMToken.tokenContractAddress,
-      functionName: "decimals",
-    }),
-    readContract(client, {
-      abi: ERC20Abi,
-      address: toEVMToken.tokenContractAddress,
-      functionName: "decimals",
-    }),
+    getERC20TokenDecimals(
+      sdkContext,
+      info.evmChain,
+      fromEVMToken.tokenContractAddress,
+    ),
+    getERC20TokenDecimals(
+      sdkContext,
+      info.evmChain,
+      toEVMToken.tokenContractAddress,
+    ),
   ])
+  if (fromTokenDecimals == null || toTokenDecimals == null) return
 
   return {
     chain: {