// ***********************************************************************
// Assembly         : Construction
// Author           : flythink
// Created          : 06-03-2020
//
// Last Modified By : flythink
// Last Modified On : 09-01-2020
// ***********************************************************************
// <copyright file="ObjectPool.cs" company="jindongfang">
// Copyright (c) jindongfang. All rights reserved.
// </copyright>
// <summary></summary>
// ***********************************************************************

namespace DQ.Construction.NewLook
{
    using System;
    using System.Collections.Concurrent;

    /// <summary>
    /// Class ObjectPool.
    /// </summary>
    /// <typeparam name="T"></typeparam>
    public class ObjectPool<T>
    {
        private readonly Func<T> objectGenerator;

        private readonly ConcurrentBag<T> objects;

        /// <summary>
        /// Initializes a new instance of the <see cref="ObjectPool{T}" /> class.
        /// </summary>
        /// <param name="objectGenerator">The object generator.</param>
        /// <exception cref="ArgumentNullException">objectGenerator</exception>
        public ObjectPool(Func<T> objectGenerator)
        {
            this.objectGenerator = objectGenerator ?? throw new ArgumentNullException(nameof(objectGenerator));
            this.objects = new ConcurrentBag<T>();
        }

        /// <summary>
        /// Gets this instance.
        /// </summary>
        /// <returns>T.</returns>
        public T Get() => this.objects.TryTake(out T item) ? item : this.objectGenerator();

        /// <summary>
        /// Returns the specified item.
        /// </summary>
        /// <param name="item">The item.</param>
        public void Return(T item) => this.objects.Add(item);
    }
}