add object pool support to a prototype - avoid small object allocation with reuse - alloc, get, release

addObjectPool.js

const isFn = (a) => typeof a === 'function';

export function addObjectPool(objtype, resetFunction, maxSize = Number.MAX_SAFE_INTEGER) {
  const pool = [];

  function newObject() {
    return new objtype();
  }

  if (isFn(resetFunction)) {
    objtype.prototype.onPoolReset = resetFunction;
  }

  objtype.prototype.release = function () {
    objtype.release(this);

    return this;
  };

  objtype.alloc = (count) => {
    if (!(count <= 0)) for (; count--; ) objtype.release(newObject());
  };

  objtype.get = () => {
    const object = pool.pop() || newObject();
    object.onPoolReset && object.onPoolReset(object);

    return object;
  };

  objtype.release = (...args) => {
    let index = args.length;
    for (; index--; ) pool.length < maxSize && pool.push(args[index]);
  };

  return objtype;
}

Example:

Given a class that has some way to reset its values to default, or this can be done in a reset funciton, we call this Functional Mixin to add object pool support. In this case, the example object already has a resetTo method that can do this.

// add pool methods:  alloc, get, release
addObjectPool(ClassName, (instance) => instance.resetTo(0));

// optional: allocate 10 objects
ClassName.alloc(10);

// get an object from the pool
const obj = ClassName.get();

// return the object to the pool
obj.release();