Programming, Coding and Others

目的：系统中有些数据不大会变化，例如人员信息，但又不想EagerLoad，想采用系统内缓存数据。如何控制Proxy的动作？

方法：1. 继承一个IProxyFactoryFactory，生成自定义的IProxyFactory。

public class ProxyFactoryFactory : IProxyFactoryFactory
    {
        public IProxyFactory BuildProxyFactory()
        {
            return new ProxyFactory();
        }

        public IProxyValidator ProxyValidator
        {
            get
            {
                return new DynProxyTypeValidator();
            }
        }
    }

2. 写自定义IProxyFactory

public class ProxyFactory : AbstractProxyFactory
   {
       private static readonly LinFu.DynamicProxy.ProxyFactory factory = new LinFu.DynamicProxy.ProxyFactory();
       protected static readonly ILog log = LogManager.GetLogger(typeof(NHibernate.ByteCode.LinFu.ProxyFactory));

       public override INHibernateProxy GetProxy(object id, ISessionImplementor session)
       {
           INHibernateProxy proxy;
           try
           {
               NHibernate.ByteCode.LinFu.LazyInitializer interceptor = new NHibernate.ByteCode.LinFu.LazyInitializer(this.EntityName, this.PersistentClass, id, this.GetIdentifierMethod, this.SetIdentifierMethod, this.ComponentIdType, session);
               object obj2 = base.IsClassProxy ? factory.CreateProxy(this.PersistentClass, interceptor, this.Interfaces) : factory.CreateProxy(this.Interfaces[0], interceptor, this.Interfaces);
               proxy = (INHibernateProxy)obj2;

               object target = TryGetCachedTarget(this.PersistentClass, id);
               if (target != null)
               {
                   interceptor.SetImplementation(target);
               }
           }
           catch (Exception exception)
           {
               log.Error("Creating a proxy instance failed", exception);
               throw new HibernateException("Creating a proxy instance failed", exception);
           }
           return proxy;
       }

       private object TryGetCachedTarget(Type persistentClass, object id)
       {
           //return buffered entity
       }
   }

这里采用LinFu的LazyInitializer，首先尝试读系统缓存，如果没用，用原有LazyInitializer，如果有，则用缓存内内容，然后设置好LazyInitializer的target。