Cached posts and ratelimited api

backend/src/controllers/postController.ts

@@ -136,6 +136,13 @@ const fetchPosts = asyncHandler(async (req: Request, res: Response) => {
   const postsPerPage = 4;
   const offset = (pageNumber - 1) * postsPerPage;
 
+  const cacheKey = `posts:${collegeId || "all"}:page:${pageNumber}`;
+
+  const cachedResults = await getCachedData(cacheKey);
+  if (cachedResults) {
+    return res.status(200).json(JSON.parse(cachedResults));
+  }
+
   const posts = await prisma.post.findMany({
     where: collegeId ? { college_id: collegeId } : {},
     orderBy: {
@@ -170,6 +177,9 @@ const fetchPosts = asyncHandler(async (req: Request, res: Response) => {
   const totalPosts = await prisma.post.count();
   const isOver = offset + postsPerPage >= totalPosts;
 
+  const result = { posts, isOver };
+  await setCachedData(cacheKey, JSON.stringify(result), 600);
+
   return res.status(200).json({ posts, isOver });
 });
 

backend/src/middleware/rateLimit.ts

@@ -0,0 +1,40 @@
+import { Request, Response, NextFunction } from "express";
+import asyncHandler from "express-async-handler";
+import Redis from "ioredis";
+
+const redisUrl = process.env.REDIS_URL;
+if (!redisUrl) {
+  throw new Error("REDIS_URL is not defined");
+}
+const redis = new Redis(redisUrl);
+const MAX_REQUESTS = 100;
+const WINDOW_SIZE_IN_SECONDS = 60;
+
+const rateLimiter = asyncHandler(
+  //@ts-ignore
+  async (req: Request, res: Response, next: NextFunction) => {
+    //@ts-ignore
+    const clientIp = req.user.user_id;
+    // console.log(clientIp);
+    const key = `rate-limit:${clientIp}`;
+    const requestCount = await redis.get(key);
+
+    if (requestCount && parseInt(requestCount) >= MAX_REQUESTS) {
+      return res
+        .status(429)
+        .json({ message: "Too many requests, please try again later." });
+    }
+
+    const ttl = await redis.ttl(key);
+
+    if (ttl < 0) {
+      await redis.set(key, 1, "EX", WINDOW_SIZE_IN_SECONDS);
+    } else {
+      await redis.incr(key);
+    }
+
+    next();
+  }
+);
+
+export default rateLimiter;

backend/src/routes/postsRoutes.ts

@@ -14,20 +14,21 @@ import {
   deletePost,
 } from "../controllers/postController";
 import checkAuth from "../middleware/checkAuth";
+import rateLimiter from "../middleware/rateLimit";
 
 const postsRoutes = express.Router();
 
-postsRoutes.get("/communities", checkAuth, getCommunities);
-postsRoutes.post("/create", checkAuth, createPost);
-postsRoutes.post("/fetch", checkAuth, fetchPosts);
-postsRoutes.post("/like", checkAuth, likePost);
-postsRoutes.get("/fetch/:id", checkAuth, fetchSinglePost);
-postsRoutes.post("/comment", checkAuth, createComment);
-postsRoutes.post("/liked", checkAuth, postLiked);
-postsRoutes.post("/unlike", checkAuth, unlikePost);
-postsRoutes.post("/search", checkAuth, searchPosts);
-postsRoutes.get("/allcommunities", checkAuth, getAllCommunities);
-postsRoutes.post("/deletecomment", checkAuth, deleteComment);
-postsRoutes.post("/deletepost", checkAuth, deletePost);
+postsRoutes.get("/communities", checkAuth, rateLimiter, getCommunities);
+postsRoutes.post("/create", checkAuth, rateLimiter, createPost);
+postsRoutes.post("/fetch", checkAuth, rateLimiter, fetchPosts);
+postsRoutes.post("/like", checkAuth, rateLimiter, likePost);
+postsRoutes.get("/fetch/:id", checkAuth, rateLimiter, fetchSinglePost);
+postsRoutes.post("/comment", checkAuth, rateLimiter, createComment);
+postsRoutes.post("/liked", checkAuth, rateLimiter, postLiked);
+postsRoutes.post("/unlike", checkAuth, rateLimiter, unlikePost);
+postsRoutes.post("/search", checkAuth, rateLimiter, searchPosts);
+postsRoutes.get("/allcommunities", checkAuth, rateLimiter, getAllCommunities);
+postsRoutes.post("/deletecomment", checkAuth, rateLimiter, deleteComment);
+postsRoutes.post("/deletepost", checkAuth, rateLimiter, deletePost);
 
 export default postsRoutes;