OxiPNG + threads PoC

codecs/oxipng/spawn.js

@@ -0,0 +1,32 @@
+let main = new Worker("./main.js", { type: "module" });
+
+let workers = Array.from(
+  { length: navigator.hardwareConcurrency },
+  () => new Worker("./worker.js", { type: "module" })
+);
+
+main.addEventListener('message', ({ data: { type, data } }) => {
+  if (type === 'spawn') {
+    workers.pop().postMessage(data);
+  }
+});
+
+let ID = 0;
+
+export function optimise(...args) {
+  return new Promise((resolve, reject) => {
+    let sendId = ID++;
+
+    main.addEventListener('message', function onMessage({ data: { ok, id, result } }) {
+      if (id !== sendId) return;
+      main.removeEventListener('message', onMessage);
+      if (ok) {
+        resolve(result);
+      } else {
+        reject(result);
+      }
+    });
+
+    main.postMessage({ id: sendId, args });
+  });
+}