add caching of responses (for 5mins)

apps/node/src/routes/proxy.ts

@@ -26,7 +26,6 @@ export default class ProxyRoute extends Route {
       res.status(400).json(RouteMessages.badRequest("No URL provided"));
       return;
     }
-    // TODO: handle rate limiting? and/or caching?
     try {
       const response = await axios.get(url, {
         headers: {

apps/proxy/package.json

@@ -17,6 +17,7 @@
     "server": "workspace:*",
     "ts-node": "^10.9.1",
     "typescript": "^5.2.2",
-    "utils": "workspace:*"
+    "utils": "workspace:*",
+    "node-cache": "^5.1.2"
   }
 }

apps/proxy/src/routes/proxy.ts

@@ -1,9 +1,41 @@
 import { Request, Response } from "express";
+import Cache from "node-cache";
 import { Route, RouteMessages } from "server";
 import { nodeManager } from "..";
 
 const IGNORED_PATHS = ["/favicon.ico"];
 
+const cache = new Cache({
+  stdTTL: 300, // 5 minutes
+});
+type CachedRequest = {
+  nodeId: string;
+  status: number;
+  headers: any;
+  data: any;
+};
+
+/**
+ * Logs a request
+ *
+ * @param nodeId the node ID that handled the request
+ * @param url the URL of the request
+ * @param status the status code of the request
+ * @param time the time it took to handle the request (or true if it was cached)
+ */
+function log(
+  nodeId: string,
+  url: string,
+  status: number,
+  time: number | boolean
+) {
+  console.log(
+    `[node: ${nodeId}] ${url} - ${status} (${
+      time === true ? "cached" : time + "ms"
+    })`
+  );
+}
+
 export default class ProxyRoute extends Route {
   constructor() {
     super({ path: "/" });
@@ -29,8 +61,19 @@ export default class ProxyRoute extends Route {
     }
 
     try {
+      const cachedRequest = cache.get<CachedRequest>(url);
+      if (cachedRequest) {
+        log(cachedRequest.nodeId, url, cachedRequest.status, true);
+        res
+          .status(cachedRequest.status)
+          .set(cachedRequest.headers)
+          .json(cachedRequest.data);
+        return;
+      }
+
       const before = Date.now();
       const response = await node.fetch(url);
+      const nodeId = response.headers["x-proxy-node"];
       const data = response.data;
 
       if (response.status === 500) {
@@ -38,15 +81,16 @@ export default class ProxyRoute extends Route {
         return;
       }
 
-      // Log the request
-      console.log(
-        `[node: ${response.headers["x-proxy-node"]}] ${url} - ${
-          response.status
-        } (${Date.now() - before}ms)`
-      );
+      log(nodeId, url, response.status, Date.now() - before);
 
       // Return the JSON response
       res.status(response.status).set(response.headers).json(data);
+      cache.set(url, {
+        nodeId: nodeId,
+        status: response.status,
+        headers: response.headers,
+        data: data,
+      } as CachedRequest);
     } catch (ex: any) {
       res.status(500).json(RouteMessages.internalServerError(ex.message || ex));
     }