Add load testing scripts for relay stress testing

scripts/agent/load-test-relay.mjs

@@ -0,0 +1,100 @@
+import { WebSocketServer } from "ws";
+import { matchFilters } from "nostr-tools/filter";
+import { fileURLToPath } from "url";
+
+export function startRelay(port = 8889) {
+  const wss = new WebSocketServer({ port });
+  const events = new Map(); // id -> event
+  const maxEvents = 10000;
+  const subs = new Map(); // ws -> Map(subId -> filters)
+
+  console.log(`Load Test Relay starting on port ${port}`);
+
+  wss.on("connection", (ws) => {
+    subs.set(ws, new Map());
+
+    ws.on("message", (message) => {
+      try {
+        const data = JSON.parse(message);
+        if (!Array.isArray(data)) return;
+
+        const [type, ...payload] = data;
+
+        if (type === "EVENT") {
+          const event = payload[0];
+          if (!event || !event.id) {
+            ws.send(JSON.stringify(["NOTICE", "Invalid event"]));
+            return;
+          }
+
+          if (!events.has(event.id)) {
+            // Eviction logic
+            if (events.size >= maxEvents) {
+              const firstKey = events.keys().next().value;
+              events.delete(firstKey);
+            }
+
+            events.set(event.id, event);
+
+            // Broadcast to matching subs
+            for (const [client, clientSubs] of subs.entries()) {
+              if (client.readyState !== 1) continue; // OPEN
+              for (const [subId, filters] of clientSubs.entries()) {
+                if (matchFilters(filters, event)) {
+                  client.send(JSON.stringify(["EVENT", subId, event]));
+                }
+              }
+            }
+          }
+
+          ws.send(JSON.stringify(["OK", event.id, true, "saved"]));
+        } else if (type === "REQ") {
+          const subId = payload[0];
+          const filters = payload.slice(1);
+
+          if (typeof subId !== "string") return;
+
+          subs.get(ws).set(subId, filters);
+
+          // Send stored events
+          for (const event of events.values()) {
+            if (matchFilters(filters, event)) {
+              ws.send(JSON.stringify(["EVENT", subId, event]));
+            }
+          }
+          ws.send(JSON.stringify(["EOSE", subId]));
+        } else if (type === "CLOSE") {
+          const subId = payload[0];
+          if (typeof subId === "string") {
+            subs.get(ws).delete(subId);
+          }
+        }
+      } catch (err) {
+        // console.error("Relay error processing message:", err);
+      }
+    });
+
+    ws.on("close", () => {
+      subs.delete(ws);
+    });
+
+    ws.on("error", (err) => {
+      console.error("Relay connection error:", err);
+    });
+  });
+
+  return {
+    close: () => {
+      return new Promise((resolve) => {
+        wss.close(resolve);
+      });
+    },
+    port
+  };
+}
+
+// Allow running standalone
+if (process.argv[1] === fileURLToPath(import.meta.url)) {
+  const port = process.env.PORT ? parseInt(process.env.PORT) : 8889;
+  startRelay(port);
+}