From 3ccf69e10a7215159196157b85e38c23f07af253 Mon Sep 17 00:00:00 2001
From: Peter Stockings <pstockings@jadeworld.com>
Date: Sun, 27 Jul 2025 22:02:19 +1000
Subject: [PATCH] Dont cache code, may need to revert

---
 deno_server.ts | 67 ++++++++++++++++++++++++++++++++++++++++----------
 worker.ts      | 16 +++++-------
 2 files changed, 60 insertions(+), 23 deletions(-)

diff --git a/deno_server.ts b/deno_server.ts
index 56fcb8e..7da90a5 100644
--- a/deno_server.ts
+++ b/deno_server.ts
@@ -6,13 +6,13 @@ const States = Object.freeze({
   TIMEOUT: "TIMEOUT",
 });
 
-async function handler(req: Request): Promise<Response> {
-  if (req.method !== "POST" || new URL(req.url).pathname !== "/execute") {
-    return new Response("Not Found", { status: 404 });
-  }
+// Create a pool of workers.
+const workerPool: { worker: Worker; inUse: boolean }[] = [];
+// Allow the number of workers to be configured via an environment variable.
+const numWorkers =
+  parseInt(Deno.env.get("NUM_WORKERS") || "0") || navigator.hardwareConcurrency;
 
-  // For each request, spawn a new worker, use it, and then terminate it.
-  // This ensures a clean, stateless environment for every execution.
+for (let i = 0; i < numWorkers; i++) {
   const worker = new Worker(new URL("./worker.ts", import.meta.url).href, {
     type: "module",
     deno: {
@@ -20,6 +20,47 @@ async function handler(req: Request): Promise<Response> {
       permissions: "inherit",
     },
   });
+  workerPool.push({ worker, inUse: false });
+}
+
+const requestQueue: ((
+  value:
+    | { worker: Worker; inUse: boolean }
+    | PromiseLike<{ worker: Worker; inUse: boolean }>
+) => void)[] = [];
+
+function getAvailableWorker() {
+  return new Promise((resolve) => {
+    const availableWorker = workerPool.find((w) => !w.inUse);
+    if (availableWorker) {
+      availableWorker.inUse = true;
+      resolve(availableWorker);
+    } else {
+      requestQueue.push(resolve);
+    }
+  });
+}
+
+function releaseWorker(worker) {
+  if (requestQueue.length > 0) {
+    const nextRequest = requestQueue.shift();
+    if (nextRequest) {
+      nextRequest(worker);
+    }
+  } else {
+    worker.inUse = false;
+  }
+}
+
+async function handler(req: Request): Promise<Response> {
+  if (req.method !== "POST" || new URL(req.url).pathname !== "/execute") {
+    return new Response("Not Found", { status: 404 });
+  }
+
+  const availableWorker = (await getAvailableWorker()) as {
+    worker: Worker;
+    inUse: boolean;
+  };
 
   try {
     const body = await req.json();
@@ -34,8 +75,8 @@ async function handler(req: Request): Promise<Response> {
       let timeoutId: number;
 
       const cleanup = () => {
-        worker.removeEventListener("message", messageHandler);
-        worker.removeEventListener("error", errorHandler);
+        availableWorker.worker.removeEventListener("message", messageHandler);
+        availableWorker.worker.removeEventListener("error", errorHandler);
         if (timeoutId) clearTimeout(timeoutId);
       };
 
@@ -54,10 +95,10 @@ async function handler(req: Request): Promise<Response> {
         reject(new Error("Timeout"));
       }, TIMEOUT_MS);
 
-      worker.addEventListener("message", messageHandler);
-      worker.addEventListener("error", errorHandler);
+      availableWorker.worker.addEventListener("message", messageHandler);
+      availableWorker.worker.addEventListener("error", errorHandler);
 
-      worker.postMessage({ code, request, environment, name });
+      availableWorker.worker.postMessage({ code, request, environment, name });
     });
 
     const startTime = performance.now();
@@ -83,12 +124,12 @@ async function handler(req: Request): Promise<Response> {
   } catch (e) {
     return new Response(`Bad Request: ${e.message}`, { status: 400 });
   } finally {
-    worker.terminate(); // Ensure the worker is always terminated.
+    releaseWorker(availableWorker); // Release the worker.
   }
 }
 
 const port = parseInt(Deno.env.get("PORT") || "8000");
 
-console.log(`⚡ Deno server ready on :${port}`);
+console.log(`⚡ Deno server ready on :${port} with ${numWorkers} workers.`);
 
 await serve(handler, { port });
diff --git a/worker.ts b/worker.ts
index eea83f5..7c9b98d 100644
--- a/worker.ts
+++ b/worker.ts
@@ -1,5 +1,5 @@
 // isolator/worker.ts
-const moduleCache = new Map();
+// No module cache to ensure fresh code for every execution.
 
 const States = Object.freeze({
   SUCCESS: "SUCCESS",
@@ -52,15 +52,11 @@ self.onmessage = async (e) => {
         status
       );
 
-    let userModule = moduleCache.get(code);
-    if (!userModule) {
-      // Use a data URL to import the user's code as an ES module.
-      const dataUrl = `data:text/javascript;base64,${btoa(
-        unescape(encodeURIComponent(code))
-      )}`;
-      userModule = await import(dataUrl);
-      moduleCache.set(code, userModule);
-    }
+    // Use a data URL to import the user's code as a fresh ES module on every execution.
+    const dataUrl = `data:text/javascript;base64,${btoa(
+      unescape(encodeURIComponent(code))
+    )}`;
+    const userModule = await import(dataUrl);
 
     if (typeof userModule.default !== "function") {
       throw new Error(