feat: base caching (#55)

# 🤖 Linear

Closes ZKS-208 Closes ZKS-199

## Description

- Added caching of 60s default to `ecosystem` and `zkchain` endpoints
- Moved core contract addresses from hardcoded config to env variables

We decided to move forward with `NodeCache` since `cacheable` by nature
uses Promises so hit the cache, this causes some problems when trying to
override `res.json` hook on express since `res.json` is considered sync.

For next steps we will:
- keep using NodeCache as Highlevel api caching
- keep using `cacheable` for modules advanced caching 
- analyze with more time if we can effectively use `cacheable` for the
cacheMiddleware

apps/api/.env.example

@@ -1,6 +1,11 @@
 PORT=3000 # Port to run the API server on
-L1_RPC_URLS="" #CSV list of L2 RPC URLs
-L2_RPC_URLS="" #CSV list of L1 RPC URLs
+
+BRIDGE_HUB_ADDRESS="" 
+SHARED_BRIDGE_ADDRESS="" 
+STATE_MANAGER_ADDRESSES="" #CSV list of State managers addresses
+
+L1_RPC_URLS="" #CSV list of L1 RPC URLs
+L2_RPC_URLS="" #CSV list of L2 RPC URLs
 
 COINGECKO_API_KEY='' # CoinGecko API key
 COINGECKO_BASE_URL='' # CoinGecko API base URL for the API version you are using

apps/api/package.json

@@ -17,15 +17,16 @@
         "test:cov": "vitest run --config vitest.config.ts --coverage"
     },
     "dependencies": {
+        "@zkchainhub/chain-providers": "workspace:*",
         "@zkchainhub/metrics": "workspace:*",
         "@zkchainhub/pricing": "workspace:*",
-        "@zkchainhub/chain-providers": "workspace:*",
         "@zkchainhub/shared": "workspace:*",
         "bignumber.js": "9.1.2",
         "cache-manager": "5.7.6",
         "cors": "2.8.5",
         "dotenv": "16.4.5",
         "express": "4.19.2",
+        "node-cache": "5.1.2",
         "swagger-ui-express": "5.0.1",
         "viem": "2.19.6",
         "yaml": "2.5.0",

apps/api/src/common/config/index.ts

@@ -1,5 +1,5 @@
 import dotenv from "dotenv";
-import { Address } from "viem";
+import { Address, isAddress } from "viem";
 import { mainnet, zksync } from "viem/chains";
 import { z } from "zod";
 
@@ -9,6 +9,16 @@ dotenv.config();
 
 const logger = Logger.getInstance();
 
+const addressArraySchema = z
+    .string()
+    .transform((str) => str.split(","))
+    .refine((addresses) => addresses.every((address) => isAddress(address)), {
+        message: "Must be a comma-separated list of valid Addresses",
+    });
+const addressSchema = z.string().refine((address) => isAddress(address), {
+    message: "Must be a valid Address",
+});
+
 const urlArraySchema = z
     .string()
     .transform((str) => str.split(","))
@@ -18,6 +28,9 @@ const urlArraySchema = z
 
 const validationSchema = z.object({
     PORT: z.coerce.number().positive().default(3000),
+    BRIDGE_HUB_ADDRESS: addressSchema,
+    SHARED_BRIDGE_ADDRESS: addressSchema,
+    STATE_MANAGER_ADDRESSES: addressArraySchema,
     L1_RPC_URLS: urlArraySchema,
     L2_RPC_URLS: z
         .union([z.literal(""), urlArraySchema])
@@ -54,9 +67,9 @@ export const config = {
                   chain: zksync,
               }
             : undefined,
-    bridgeHubAddress: "0x303a465B659cBB0ab36eE643eA362c509EEb5213" as Address,
-    sharedBridgeAddress: "0xD7f9f54194C633F36CCD5F3da84ad4a1c38cB2cB" as Address,
-    stateTransitionManagerAddresses: ["0xc2eE6b6af7d616f6e27ce7F4A451Aedc2b0F5f5C"] as Address[],
+    bridgeHubAddress: envData.BRIDGE_HUB_ADDRESS as Address,
+    sharedBridgeAddress: envData.SHARED_BRIDGE_ADDRESS as Address,
+    stateTransitionManagerAddresses: envData.STATE_MANAGER_ADDRESSES as Address[],
     pricing: {
         cacheOptions: {
             ttl: envData.CACHE_TTL,

apps/api/src/common/middleware/cache.middleware.ts

@@ -0,0 +1,36 @@
+import { NextFunction, Request, Response } from "express";
+import NodeCache from "node-cache";
+
+const DEFAULT_TTL = 60; // 1 minute
+const cache = new NodeCache();
+
+//FIXME: This is a temporary cache implementation. It is not recommended for production use.
+// might be replaced with a more robust solution in the future.
+/**
+ * A middleware that caches responses for a given time to live (TTL).
+ * @param args - The time to live (TTL) in seconds for the cached response.
+ * @returns A middleware function that caches responses for a given time to live (TTL).
+ */
+export function cacheMiddleware(args: { ttl: number } = { ttl: DEFAULT_TTL }) {
+    return async (req: Request, res: Response, next: NextFunction): Promise<void> => {
+        const key = req.originalUrl || req.url;
+        const cachedResponse = await cache.get(key);
+        if (cachedResponse) {
+            // Check if the cached response is a JSON object or plain text
+            res.json(cachedResponse);
+        } else {
+            // Store the original send and json functions
+            const originalJson = res.json.bind(res);
+            // Override the json function
+
+            res.json = (body): Response => {
+                // Cache the response body
+                cache.set(key, body, args.ttl);
+                // Call the original json function with the response body
+                return originalJson(body);
+            };
+
+            next();
+        }
+    };
+}

apps/api/src/index.ts

@@ -1,11 +1,11 @@
 import { inspect } from "util";
 import { caching } from "cache-manager";
 
+import { EvmProvider } from "@zkchainhub/chain-providers/dist/src/index.js";
 import { L1MetricsService } from "@zkchainhub/metrics";
 import { CoingeckoProvider } from "@zkchainhub/pricing";
 import { Logger } from "@zkchainhub/shared";
 
-import { EvmProvider } from "../../../packages/chain-providers/dist/src/index.js";
 import { App } from "./app.js";
 import { config } from "./common/config/index.js";
 import { MetricsController, MetricsRouter } from "./metrics/index.js";

apps/api/src/metrics/routes/index.ts

@@ -2,6 +2,7 @@ import { z } from "zod";
 
 import { ILogger } from "@zkchainhub/shared";
 
+import { cacheMiddleware } from "../../common/middleware/cache.middleware.js";
 import { BaseRouter } from "../../common/routes/baseRouter.js";
 import { ChainNotFound, MetricsController } from "../index.js";
 
@@ -27,7 +28,7 @@ export class MetricsRouter extends BaseRouter {
          * Retrieves the ecosystem information.
          * @returns {Promise<EcosystemInfo>} The ecosystem information.
          */
-        this.router.get("/ecosystem", async (_req, res, next) => {
+        this.router.get("/ecosystem", cacheMiddleware(), async (_req, res, next) => {
             try {
                 const data = await this.metricsController.getEcosystem();
                 res.json(data);
@@ -42,7 +43,7 @@ export class MetricsRouter extends BaseRouter {
          * @param {number} chainId - The ID of the chain.
          * @returns {Promise<ZKChainInfo>} The chain information.
          */
-        this.router.get("/zkchain/:chainId", async (req, res, next) => {
+        this.router.get("/zkchain/:chainId", cacheMiddleware(), async (req, res, next) => {
             try {
                 const { params } = ChainIdSchema.parse(req);
 

packages/metrics/src/l1/l1MetricsService.ts

@@ -11,6 +11,7 @@ import {
     zeroAddress,
 } from "viem";
 
+import { EvmProvider } from "@zkchainhub/chain-providers/dist/src/index.js";
 import { IPricingProvider } from "@zkchainhub/pricing";
 import {
     BatchesInfo,
@@ -27,7 +28,6 @@ import {
     WETH,
 } from "@zkchainhub/shared";
 
-import { EvmProvider } from "../../../chain-providers/dist/src/index.js";
 import {
     AssetTvl,
     bridgeHubAbi,

packages/metrics/test/unit/l1/l1MetricsService.spec.ts

@@ -1,6 +1,7 @@
 import { Address, encodeFunctionData, erc20Abi, parseEther, zeroAddress } from "viem";
 import { afterEach, describe, expect, it, Mocked, vi } from "vitest";
 
+import { EvmProvider, MulticallNotFound } from "@zkchainhub/chain-providers/dist/src/index.js";
 import { IPricingProvider } from "@zkchainhub/pricing";
 import {
     BatchesInfo,
@@ -15,7 +16,6 @@ import {
     WETH,
 } from "@zkchainhub/shared";
 
-import { EvmProvider, MulticallNotFound } from "../../../../chain-providers/dist/src/index.js";
 import {
     bridgeHubAbi,
     diamondProxyAbi,