added session life cycle management

Author: viveknotfound

src/exec/session.ts

@@ -0,0 +1,73 @@
+import { runtimeStore } from "../runtime/store.js";
+import { cleanupVm } from "../runtime/cleanup.js";
+import { sessionLogger } from "../utils/logger.js";
+
+export interface Session {
+  sessionId: string;
+  createdAt: number;
+  lastActivityAt: number;
+  state: "creating" | "active" | "destroying";
+}
+
+const sessions = new Map<string, Session>();
+
+export function getSession(sessionId: string): Session | undefined {
+  return sessions.get(sessionId);
+}
+
+export function createSession(sessionId: string): Session {
+  const session: Session = {
+    sessionId,
+    createdAt: Date.now(),
+    lastActivityAt: Date.now(),
+    state: "creating",
+  };
+  sessions.set(sessionId, session);
+  return session;
+}
+
+export function touchSession(sessionId: string): void {
+  const session = sessions.get(sessionId);
+  if (session) session.lastActivityAt = Date.now();
+}
+
+export async function destroySession(sessionId: string): Promise<boolean> {
+  const session = sessions.get(sessionId);
+  if (!session) return false;
+
+  session.state = "destroying";
+
+  const fn = runtimeStore.functions.get(sessionId);
+  if (fn) {
+    for (const vm of [...fn.vms]) {
+      await cleanupVm(fn, vm);
+    }
+    runtimeStore.functions.delete(sessionId);
+  }
+
+  sessions.delete(sessionId);
+  sessionLogger.info({ sessionId }, "session destroyed");
+  return true;
+}
+
+export function getActiveSessions(): number {
+  return sessions.size;
+}
+
+export function getAllSessions(): Session[] {
+  return [...sessions.values()];
+}
+
+export function startSessionReaper(ttlMs: number = 30 * 60 * 1000): void {
+  setInterval(() => {
+    const now = Date.now();
+    for (const [id, session] of sessions) {
+      if (now - session.lastActivityAt > ttlMs && session.state === "active") {
+        sessionLogger.info({ sessionId: id, idleMs: now - session.lastActivityAt }, "reaping idle session");
+        destroySession(id).catch(err => {
+          sessionLogger.error({ sessionId: id, err }, "session reap failed");
+        });
+      }
+    }
+  }, 60_000);
+}

src/utils/logger.ts

@@ -33,6 +33,7 @@ export const vmManagerLogger = logger.child({ module: "vm-manager" });
 export const transportLogger = logger.child({ module: "transport" });
 export const protocolLogger = logger.child({ module: "protocol" });
 export const cleanupLogger = logger.child({ module: "cleanup" });
+export const sessionLogger = logger.child({module: "session"})
 
 export const httpLoggerOptions: Options = {
   logger: logger.child({ module: "http" }),