back_cantanBuilding/Assets/Scripts/Pool/ObjectPool.cs

using System;
using System.Collections;
using System.Collections.Generic;

namespace asap.core.common
{
    public interface IObjectPool
    {
        // string PoolId { get; }

        Type ObjectType { get; }
        int PoolObjectNum { get; }

        object SpawnObject();

        bool DespawnObject(object obj, float delay = 0f);

        void Initialize();
        void Release();
    }

    // public interface IObjectPool<T> : IObjectPool where T : class
    // {
    //     new T SpawnObject();
    //     void DespawnObject(T obj);
    // }

    public interface IPoolableObject
    {
        void OnSpawn();
        void OnDespawn();

        void OnPoolCreate(IObjectPool objectPool);
        //void Destroy();
        void OnPoolDestroy();
        void ReturnPool();
    }

    public abstract class AObjectPool : IObjectPool
    {
        protected Queue<object> objectQuene = new Queue<object>();

        protected Type objType;
        protected int maxSize;
        protected int preloadNum;

        public Type ObjectType { get { return objType; } }

        public int PoolObjectNum { get { return (null == objectQuene) ? 0 : objectQuene.Count; } }

        protected string poolId;
        public string PoolId => poolId;

        public AObjectPool(Type objType, int preloadNum, int maxSize)
        {
            this.objType = objType;
            this.maxSize = maxSize;
            this.preloadNum = preloadNum;

            //Initialize();
        }

        public virtual void Initialize()
        {
            if (objType == null)
            {
                throw (new ArgumentNullException("objType"));
            }

            if (preloadNum > 0)
            {
                generateObjects(preloadNum);
            }
        }

        public virtual void Release()
        {
            foreach (var obj in objectQuene)
            {
                destroyObject(obj);
            }

            objectQuene.Clear();
            objectQuene = null;
        }

        protected void generateObjects(int num)
        {
            object obj;
            for (int i = 0; i < num; i++)
            {
                obj = newObject();
                addObject(obj);
            }
        }

        protected abstract object newObject();

        protected abstract void destroyObject(object obj);

        public virtual object SpawnObject()
        {
            object obj = getObject();

            onSpawnObject(obj);

            return obj;
        }

        public virtual bool DespawnObject(object obj, float delay = 0f)
        {
            addObject(obj);

            onDespawnObject(obj);

            return true;
        }

        protected virtual void onCreateObject(object obj)
        {
            if (obj is IPoolableObject)
            {
                var poolableObj = obj as IPoolableObject;
                poolableObj.OnPoolCreate(this);
            }
        }

        protected virtual void onSpawnObject(object obj)
        {
            if (obj is IPoolableObject)
            {
                var poolableObj = obj as IPoolableObject;
                poolableObj.OnSpawn();
            }
        }

        protected virtual void onDespawnObject(object obj)
        {
            if (obj is IList list)
            {
                list.Clear();
            }
            else if (obj is IDictionary dict)
            {
                dict.Clear();
            }
            else if (obj is ICollection collection)
            {
                var type = obj.GetType();
                var methodInfo = type.GetMethod("Clear");
                if (methodInfo != null)
                {
                    // Debug.Log($"onDespawnObject: {collection.Count}, {methodInfo}");
                    methodInfo.Invoke(obj, null);
                    // Debug.Log($"onDespawnObject: {collection.Count}");
                }
            }
            else if (obj is IPoolableObject poolableObj)
            {
                poolableObj.OnDespawn();
            }
        }

        protected virtual void onDestroyObject(object obj)
        {
            if (obj is IPoolableObject)
            {
                var poolableObj = obj as IPoolableObject;
                poolableObj.OnPoolDestroy();
            }
            if (obj is IDisposable)
            {
                (obj as IDisposable).Dispose();
            }
        }

        protected virtual object getObject()
        {
            object obj;
            if (objectQuene.Count > 0)
            {
                obj = objectQuene.Dequeue();
                // onSpawnObject(obj);
            }
            else
            {
                obj = newObject();
            }

            return obj;
        }

        protected virtual void addObject(object obj)
        {
            if(!objType.IsAssignableFrom(obj.GetType()))
                return;
            #if UNITY_EDITOR
            if (objectQuene.Contains(obj))
            {
                UnityEngine.Debug.LogError($"Return obj {obj.GetType().FullName} is already in pool");
            }
            #endif
            objectQuene.Enqueue(obj);
            // onDespawnObject(obj);
        }
    }

    public class ObjectPool : AObjectPool
    {
        public ObjectPool(Type objType, int preloadNum, int maxSize) : base(objType, preloadNum, maxSize)
        {
        }

        protected override object newObject()
        {
            object obj = Activator.CreateInstance(objType);
            onCreateObject(obj);
            return obj;
        }

        protected override void destroyObject(object obj)
        {
            onDestroyObject(obj);
        }
    }
}