我阅读了 Phillip Haydon 的这篇关于如何将 NHibernate/RavenDB 与 ServiceStack 一起使用的文章。
每次我需要数据库中的一些东西时，我都看不到获取 IDocumentStore 并打开新会话的意义，如下所示：
public class FooService : ServiceBase<Foo>
{
public IDocumentStore RavenStore{ get; set; }
protected override object Run(ProductFind request)
{
using (var session = RavenStore.OpenSession())
{
// Do Something...
return new FooResponse{/*Object init*/};
}
}
}
为什么我不能每个请求只使用一个会话，当请求结束时，根据响应状态提交更改或回滚？
如果我的方法很好，那么我该如何实施呢？这是我的尝试：
我创建了这个类：
public class RavenSession : IRavenSession
{
#region Data Members
private readonly IDocumentStore _store;
private IDocumentSession _innerSession;
#endregion
#region Properties
public IDocumentSession InnerSession
{
get { return _innerSession ?? (_innerSession = _store.OpenSession()); }
}
#endregion
#region Ctor
public RavenSession(IDocumentStore store)
{
_store = store;
}
#endregion
#region Public Methods
public void Commit()
{
if (_innerSession != null)
{
try
{
InnerSession.SaveChanges();
}
finally
{
InnerSession.Dispose();
}
}
}
public void Rollback()
{
if (_innerSession != null)
{
InnerSession.Dispose();
}
}
#endregion
#region IDocumentSession Delegation
public ISyncAdvancedSessionOperation Advanced
{
get { return InnerSession.Advanced; }
}
public void Delete<T>(T entity)
{
InnerSession.Delete(entity);
}
public ILoaderWithInclude<object> Include(string path)
{
return InnerSession.Include(path);
}
public ILoaderWithInclude<T> Include<T, TInclude>(Expression<Func<T, object>> path)
{
return InnerSession.Include<T, TInclude>(path);
}
public ILoaderWithInclude<T> Include<T>(Expression<Func<T, object>> path)
{
return InnerSession.Include(path);
}
public T Load<T>(string id)
{
return InnerSession.Load<T>(id);
}
public T[] Load<T>(params string[] ids)
{
return InnerSession.Load<T>(ids);
}
public T Load<T>(ValueType id)
{
return InnerSession.Load<T>(id);
}
public T[] Load<T>(IEnumerable<string> ids)
{
return InnerSession.Load<T>(ids);
}
public IRavenQueryable<T> Query<T, TIndexCreator>() where TIndexCreator : AbstractIndexCreationTask, new()
{
return InnerSession.Query<T, TIndexCreator>();
}
public IRavenQueryable<T> Query<T>()
{
return InnerSession.Query<T>();
}
public IRavenQueryable<T> Query<T>(string indexName)
{
return InnerSession.Query<T>(indexName);
}
public void Store(dynamic entity, string id)
{
InnerSession.Store(entity, id);
}
public void Store(object entity, Guid etag, string id)
{
InnerSession.Store(entity, etag, id);
}
public void Store(object entity, Guid etag)
{
InnerSession.Store(entity, etag);
}
public void Store(dynamic entity)
{
InnerSession.Store(entity);
}
#endregion
}
现在我的服务看起来像这样：
public class FooService : ServiceBase<Foo>
{
public IRavenSession RavenSession { get; set; }
protected override object Run(ProductFind request)
{
// Do Something with RavenSession...
return new FooResponse {/*Object init*/};
}
}
但我仍然需要找到一种方法来知道何时结束提交/回滚更改的请求。
我发现最好的方法是使用 ResponseFilters：
public class AppHost : AppHostBase
{
public AppHost()
: base("", typeof (Foo).Assembly, typeof (FooService).Assembly)
{
}
public override void Configure(Container container)
{
// Some Configuration...
this.ResponseFilters.Add((httpReq, httpResp, respnseDto) =>
{
var currentSession = (RavenSession) this.Container.Resolve<IRavenSession>();
if (!httpResp.IsErrorResponse())
{
currentSession.Commit();
}
else
{
currentSession.Rollback();
}
});
// Some Configuration...
}
}
我确信有更好的方法可以做到这一点，但如何？