从二级缓存中排除某些实体 [英] Exclude certain entities from second-level caching

问题描述

我正在使用 EFCache 在我的EF上下文中提供二级缓存。

我碰到了一个问题，我的一个实体连接到一个提供行级安全性的视图。因此，此视图会根据一些参数过滤行。当使用二级缓存时，所有用户将获得相同的结果！

我正在寻找一种方法来排除某些实体缓存，任何帮助都是受欢迎的。 / p>

这是我的缓存配置：

  class CacheConfiguration：DbConfiguration 
 {
 public CacheConfiguration（）
 {
 var transactionHandler = new CacheTransactionHandler（new InMemoryCache（））; 
 
 AddInterceptor（transactionHandler）; 
 
 var cachingpolicy = new cachingpolicy（）; 
 
加载+ = 
（sender，e）=> e.ReplaceService< DbProviderServices>（
（s，_）=> new CachingProviderServices（s，transactionHandler，cachingPolicy））; 
} 
} 
  

解决方案

在这个博文。

为了排除一些实体，您需要创建一个缓存策略，并从缓存策略。

在覆盖 CanBeCached 方法后，您可以返回 false 以防止缓存。

这是我的工作代码：

  class CacheConfiguration：DbConfiguration 
 {
 public CacheConfiguration（）
 {
 var transactionHandler = new CacheTransactionHandler（new InMemoryCache（））; 
 
 AddInterceptor（transactionHandler）; 
 
 // var cachingPolicy = new CachingPolicy（）; 
 var cachingPolicy = new myCachingPolicy（）; 
 
加载+ = 
（sender，e）=> e.ReplaceService< DbProviderServices>（
（s，_）=> new CachingProviderServices（s，transactionHandler，cachingPolicy））; 
} 
} 
 
 public class myCachingPolicy：CachingPolicy 
 {
 protected override bool CanBeCached（System.Collections.ObjectModel.ReadOnlyCollection< System.Data.Entity .Core.Metadata.Edm.EntitySetBase> affectedEntitySets，string sql，IEnumerable< KeyValuePair< string，object>>参数）
 {
 string [] excludedEntities = {
permView1，
permView2，
permView3}; 
 
 if（affectedEntitySets.Where（x => excludedEntities.Contains（x.Table））。Any（））
 {
 return false; 
} 
 else 
 {
 return base.CanBeCached（affectedEntitySets，sql，parameters）; 
} 
} 
} 
  

I'm using EFCache to provide 2nd-level caching in my EF context.

I ran into a problem, where one of my entities is connected to a view which provides row-level security. So this view filters rows based on some parameters. When using 2nd-level cache, all users will get the same result!

I'm looking for a way to exclude certain entities from caching, any help is welcome.

This is my caching configuration:

class CacheConfiguration : DbConfiguration
{
    public CacheConfiguration()
    {
        var transactionHandler = new CacheTransactionHandler(new InMemoryCache());

        AddInterceptor(transactionHandler);

        var cachingpolicy = new cachingpolicy();

        Loaded +=
            (sender, e) => e.ReplaceService<DbProviderServices>(
                (s, _) => new CachingProviderServices(s, transactionHandler, cachingPolicy));
    }
}

解决方案

I found the answer in this blog post.

In order to exclude some entities, you need to create a caching policy and drive a class from CachingPolicy.

After overriding CanBeCached method, you can return false to prevent caching.

This is my working code:

class CacheConfiguration : DbConfiguration
{
    public CacheConfiguration()
    {
        var transactionHandler = new CacheTransactionHandler(new InMemoryCache());

        AddInterceptor(transactionHandler);

        //var cachingPolicy = new CachingPolicy();
        var cachingPolicy = new myCachingPolicy();

        Loaded +=
            (sender, e) => e.ReplaceService<DbProviderServices>(
                (s, _) => new CachingProviderServices(s, transactionHandler, cachingPolicy));
    }
}

public class myCachingPolicy : CachingPolicy
{
    protected override bool CanBeCached(System.Collections.ObjectModel.ReadOnlyCollection<System.Data.Entity.Core.Metadata.Edm.EntitySetBase> affectedEntitySets, string sql, IEnumerable<KeyValuePair<string, object>> parameters)
    {
        string[] excludedEntities = {
            "permView1",
            "permView2",
            "permView3"};

        if (affectedEntitySets.Where(x => excludedEntities.Contains(x.Table)).Any())
        {
            return false;
        }
        else
        {
            return base.CanBeCached(affectedEntitySets, sql, parameters);
        }
    }
}

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