Universal object pool

Question

I see the benefit of using object pooling, and I also want to combine it with Vectors. But, reading about Vectors, I see that they can only be defined at compile time, meaning a separate pooler class for each of the pooled classes is required. On the other hand, I would like to have a random class instance of a set (all extending a certain class) to be pulled from a pool at runtime, so that I don't exactly know which object pooler is to be called. And, in order to not multiply the code sequences for pooler classes, I want to combine all pools into a UniversalPooler class, which then can serve requests like var foo:SomeClass=UniversalPool.getFromPool(SomeClass);. The question is, how can I implement such a universal pooler performance effectively, using Vectors if at all possible, and probably using random subclass selection?

Answer 1

Yes, unfortunately it's not possible to use Vectors, AS3 has very poor implementation of generics. I use the following pooling based on class map Dictionary and Arrays for objects storage:

package util.pool
{
import flash.utils.Dictionary;

public class ObjectPool
{
    private var storage:Dictionary = new Dictionary();

    public function ObjectPool()
    {
    }

    private function createNew(constructor:Class, ...args):Object
    {
        //as3 - (facepalm), why there isn't API to path array of params to constructor
        switch (args.length) {
            case 0:return new constructor();
            case 1:return new constructor(args[0]);
            case 2:return new constructor(args[0], args[1]);
            case 3:return new constructor(args[0], args[1], args[2]);
            case 4:return new constructor(args[0], args[1], args[2], args[3]);
            case 5:return new constructor(args[0], args[1], args[2], args[3], args[4]);
            case 6:return new constructor(args[0], args[1], args[2], args[3], args[4], args[5]);
            case 7:return new constructor(args[0], args[1], args[2], args[3], args[4], args[5], args[6]);
            case 8:return new constructor(args[0], args[1], args[2], args[3], args[4], args[5], args[6], args[7]);
            case 9:return new constructor(args[0], args[1], args[2], args[3], args[4], args[5], args[6], args[7], args[8]);
            case 10:return new constructor(args[0], args[1], args[2], args[3], args[4], args[5], args[6], args[7], args[8], args[9]);
            default: throw new Error("too much arguments for constructor, add more switch cases :))");
        }       
    }

    public function create(constructor:Class, ...args):Object
    {
        var pool:Array = getOrCreatePool(constructor);

        var res:*;
        if(pool.length > 0)
        {
            res = pool.pop();
        }else
        {
            args.unshift(constructor);
            res = createNew.apply(null, args);
        }

        return res;
    }

    public function destroy(obj:Object):void
    {
        if(!obj) return;
        if(!(obj is Object)) return;

        var constructor:Class = obj["constructor"];
        var pool:Array = getOrCreatePool(constructor);
        pool[pool.length] = obj;
    }

    public function destroyArr(objs:Object):void
    {
        for each(var obj:Object in objs)
            destroy(obj);
    }

    private function getOrCreatePool(constructor:Class):Array
    {
        var pool:Array = storage[constructor];
        if(!pool)
        {
            pool = [];
            storage[constructor] = pool;
        }

        return pool;
    }
}
}

It can be used as one global pool. And I don't think that there can be much more effective implementation, it's a quite simple feature in general.