Implement poolify(factory, size)

tshemsedinov · tshemsedinov · commit 5cb5c81bf612 · 2018-01-06T19:12:30.000+02:00
diff --git a/JavaScript/3-poolify.js b/JavaScript/3-poolify.js
@@ -0,0 +1,33 @@
+'use strict';
+
+const poolify = (factory, size) => {
+
+  const pool = (item) => {
+    if (item) {
+      pool.items.push(item);
+      console.log('Recycle item, count =', pool.items.length);
+      return;
+    }
+    const res = pool.items.pop() || factory();
+
+    console.log('Get from pool, count =', pool.items.length);
+    return res;
+  };
+
+  const items = new Array(size).fill().map(() => factory());
+  return Object.assign(pool, { items });
+
+};
+
+// Usage
+
+// Factory to allocate 4kb buffer
+const buffer = () => new Uint32Array(128);
+
+// Allocate pool of 10 buffers
+const pool = poolify(buffer, 10);
+
+for (let i = 0; i < 15; i++) {
+  const a = pool();
+  console.log('Buffer size', a.length * 32);
+}
