Provider模式应用demo
程序员文章站
2022-08-02 22:04:13
参考ObjectPool对象池设计原理还原一个简易的Provider模式。 存储对象的数组ObjectWrapper内元素的取、还操作通过Interlock.CompareExchange巧妙的实现,并且是线程安全的。 取操作: 。取完后将元素置为null 还操作: 如果元素为null,则赋值 设计 ......
参考objectpool对象池设计原理还原一个简易的provider模式。
using system; using system.dynamic; using system.reflection.metadata.ecma335; using system.threading; using system.xml; namespace providerpattern { /// <summary> /// 目标 /// </summary> /// <typeparam name="t"></typeparam> public class targetclass<t> where t:class { private objectwrapper[] _items; private itargetclasspolicy<t> _policy; public targetclass(itargetclasspolicy<t> policy) { _policy = policy; _items = new objectwrapper[3]; } public t get() { var items = _items; for (var i = 0; i < items.length; i++) { var item = items[i].element; if (item != null && interlocked.compareexchange(ref items[i].element, null,item) != null) { return item; } } return create(); } public void return(t obj) { if (!_policy.return(obj)) { return; } var items = _items; for (var i = 0; i < items.length && interlocked.compareexchange(ref items[i].element, obj, null) != null; ++i) { } } private t create() => _policy.create(); private struct objectwrapper { public t element; } } /// <summary> /// provider 提供者 /// </summary> public class targetclassprovider { public targetclass<t> create<t>(itargetclasspolicy<t> policy) where t : class, new() { return new targetclass<t>(policy); } } /// <summary> /// policy 策略 规范 /// </summary> /// <typeparam name="t"></typeparam> public interface itargetclasspolicy<t> { t create(); bool return(t obj); } /// <summary> /// policy 具体策略类 /// </summary> /// <typeparam name="t"></typeparam> public class targetclasspolicy<t> : itargetclasspolicy<t> where t : class, new() { public t create() { return new t(); } public bool return(t obj) { return true; } } class user { public string name { get; set; } public int age { get; set; } } class program { static void main(string[] args) { var target = new targetclass<user>(new targetclasspolicy<user>()); var get = target.get(); console.writeline($"{get.name},{get.age}"); var user1 = new user() { age = 18, name = "microheart" }; var user2 = new user() { age = 19, name = "microheart" }; var user3 = new user() { age = 20, name = "microheart" }; target.return(user1); target.return(user2); target.return(user3); var get1 = target.get(); console.writeline($"{get1.name},{get1.age}"); var get2 = target.get(); console.writeline($"{get2.name},{get2.age}"); console.read(); } } }
存储对象的数组objectwrapper内元素的取、还操作通过interlock.compareexchange巧妙的实现,并且是线程安全的。
取操作:interlocked.compareexchange(ref items[i].element, null,item)
。取完后将元素置为null
还操作:interlocked.compareexchange(ref items[i].element, obj, null)
如果元素为null,则赋值
设计原理:通过policy构建provider,通过provider创建最终的目标类(target)。
参考链接:objectpool 对象池设计模式