SimplePrefabPool.cs

using System;
using UnityEngine;

namespace Client.Common {
    sealed class PrefabPool<T> : IDisposable where T : Component {
        T[] _items = new T[8];
        int _itemsCount;

        T _prefab;

        public PrefabPool (string prefabPath) {
            _prefab = Resources.Load<T> (prefabPath);
        }

        public T Get () {
            bool isNew;
            return Get (out isNew);
        }

        public T Get (out bool isNew) {
            return Get (out isNew, Vector3.zero, Quaternion.identity);
        }

        public T Get (out bool isNew, Vector3 position, Quaternion rotation) {
            if (_itemsCount > 0) {
                isNew = false;
                var item = _items[--_itemsCount];
                if (position.sqrMagnitude != 0.0f) {
                    item.gameObject.transform.position = position;
                }
                if (rotation != Quaternion.identity) {
                    item.gameObject.transform.rotation = rotation;
                }
                return item;
            }
            isNew = true;
            return UnityEngine.Object.Instantiate (_prefab, position, rotation).GetComponent<T> ();
        }

        public void Recycle (T item) {
            if (_items.Length == _itemsCount) {
                Array.Resize (ref _items, _itemsCount << 1);
            }
            _items[_itemsCount++] = item;
        }

        public void Dispose () {
            _prefab = null;
            for (var i = 0; i < _itemsCount; i++) {
                if (_items[i]) {
                    UnityEngine.Object.Destroy (_items[i].gameObject);
                }
                _items[i] = null;
            }
            _itemsCount = 0;
        }
    }
}