Improve examples

tshemsedinov · tshemsedinov · commit 8a5a6ac53017 · 2025-03-08T22:48:09.000+02:00
diff --git a/JavaScript/4-bad.js b/JavaScript/4-bad.js
@@ -1,45 +1,29 @@
 'use strict';
 
-const poolify = (factory, min, norm, max) => {
-  const duplicate = (n) => new Array(n).fill().map(() => factory());
-  const items = duplicate(norm);
+const poolify = (factory, options, size, max) => {
+  const instances = [];
+  for (let i = 0; i < size; i++) {
+    const instance = factory(...options);
+    instances.push(instance);
+  }
 
-  return (item) => {
-    if (item) {
-      if (items.length < max) {
-        items.push(item);
+  return (instance) => {
+    if (instance) {
+      if (instances.length < max) {
+        instances.push(instance);
       }
-      console.log('Recycle item, count =', items.length);
-      return null;
-    }
-    if (items.length < min) {
-      const instances = duplicate(norm - items.length);
-      items.push(...instances);
     }
-    const res = items.pop();
-    console.log('Get from pool, count =', items.length);
-    return res;
+    instance = instances.pop();
+    if (!instance) instance = factory(...options);
+    return instance;
   };
 };
 
 // Usage
 
-// Factory to allocate 4kb buffer
-const buffer = () => new Uint32Array(1024);
-
-// Allocate pool of 10 buffers
-const pool = poolify(buffer, 5, 10, 15);
-
-let i = 0;
-
-const next = () => {
-  const item = pool();
-  console.log('Buffer size', item.length * 32);
-  i++;
-  if (i < 20) {
-    setTimeout(next, i * 10);
-    setTimeout(() => pool(item), i * 100);
-  }
-};
+const createBuffer = (size) => new Uint8Array(size);
+const pool = poolify(createBuffer, [4096], 10, 15);
 
-next();
+const instance = pool();
+console.log({ instance });
+pool(instance);
diff --git a/JavaScript/4-improved.js b/JavaScript/4-improved.js
@@ -1,41 +1,27 @@
 'use strict';
 
 const poolify = (factory, { size, max }) => {
-  const duplicate = (n) => new Array(n).fill(null).map(factory);
+  const instances = new Array(size).fill(null).map(factory);
 
-  const instances = duplicate(size);
-
-  const acquire = () => {
-    const instance = instances.pop() || factory();
-    console.log('Get from pool, count =', instances.length);
-    return instance;
-  };
+  const acquire = () => instances.pop() || factory();
 
   const release = (instance) => {
     if (instances.length < max) {
       instances.push(instance);
     }
-    console.log('Recycle item, count =', instances.length);
   };
 
   return { acquire, release };
 };
 
 // Usage
 
-const buffer = () => new Uint32Array(1024);
+const createBuffer = (size) => new Uint8Array(size);
 
-const pool = poolify(buffer, { size: 10, max: 15 });
-
-let i = 0;
-const next = () => {
-  const data = pool.acquire();
-  console.log('Buffer size', data.length * 32);
-  i++;
-  if (i < 20) {
-    setTimeout(next, i * 10);
-    setTimeout(() => pool.release(data), i * 100);
-  }
-};
+const FILE_BUFFER_SIZE = 4096;
+const createFileBuffer = () => createBuffer(FILE_BUFFER_SIZE);
 
-next();
+const pool = poolify(createFileBuffer, { size: 10, max: 15 });
+const instance = pool.acquire();
+console.log({ instance });
+pool.release(instance);
