实体框架使用了大量内存

Question

这是来自ANTS内存分析器的图像.它认为内存中有很多对象.我怎么能找到我做错了什么？

**UPDATE**

这是我的存储库类:

public class Repository<T> : IRepository<T> where T : class, IDataEntity
    {
        ObjectContext _context;
        IObjectSet<T> _objectSet;

        readonly string _entitySetName;
        readonly string[] _keyNames;

        private ObjectContext Context
        {
            get
            {
                if (_context == null)
                {
                    _context = GetCurrentUnitOfWork<EFUnitOfWork>().Context;
                }
                return _context;
            }
        }

        private IObjectSet<T> ObjectSet
        {
            get
            {
                if (_objectSet == null)
                {
                    _objectSet = this.Context.CreateObjectSet<T>();
                }
                return _objectSet;
            }
        }

        public TUnitOfWork GetCurrentUnitOfWork<TUnitOfWork>() where TUnitOfWork : IUnitOfWork
        {
            return (TUnitOfWork)UnitOfWork.Current;
        }

        public virtual IEnumerable<T> GetQuery()
        {
            return ObjectSet;
        }

        public virtual IEnumerable<T> GetQuery(params Expression<Func<T, object>>[] includes)
        {
            return ObjectSet.IncludeMultiple(includes);
        }

        public virtual IEnumerable<T> GetQuery(
            IEnumerable<Expression<Func<T, bool>>> filters,
            Func<IQueryable<T>, IOrderedQueryable<T>> orderBy,
            IEnumerable<Expression<Func<T, object>>> includes)
        {
            IQueryable<T> _query = ObjectSet;

            if (filters != null)
            {
                foreach (var filter in filters)
                {
                    _query = _query.Where(filter);
                }
            }

            if (includes != null && includes.Count() > 0)
            {
                _query = _query.IncludeMultiple(includes.ToArray());
            }

            if (orderBy != null)
            {
                _query = orderBy(_query);
            }

            return _query;
        }

        public virtual IPaged<T> GetQuery(
            IEnumerable<Expression<Func<T, bool>>> filters,
            Func<IQueryable<T>, IOrderedQueryable<T>> orderBy,
            int pageNumber, int pageSize,
            IEnumerable<Expression<Func<T, object>>> includes)
        {
            IQueryable<T> _query = ObjectSet;

            if (filters != null)
            {
                foreach (var filter in filters)
                {
                    _query = _query.Where(filter);
                }
            }

            if (orderBy != null)
            {
                _query = orderBy(_query);
            }

            IPaged<T> page = new Paged<T>(_query, pageNumber, pageSize, includes);

            return page;
        }

        public virtual void Insert(T entity)
        {
            this.ObjectSet.AddObject(entity);
        }

        public virtual void Delete(T entity)
        {
            if (entity is ISoftDeletable)
            {
                ((ISoftDeletable)entity).IsDeleted = true;
                //Update(entity);
            }
            else
            {
                this.ObjectSet.DeleteObject(entity);
            }
        }

        public virtual void Attach(T entity)
        {
            ObjectStateEntry entry = null;
            if (this.Context.ObjectStateManager.TryGetObjectStateEntry(entity, out entry) == false)
            {
                this.ObjectSet.Attach(entity);
            }
        }

        public virtual void Detach(T entity)
        {
            ObjectStateEntry entry = null;
            if (this.Context.ObjectStateManager.TryGetObjectStateEntry(entity, out entry) == true)
            {
                this.ObjectSet.Detach(entity);
            }
        }
    }

现在,如果我有A类来保存表A中的记录,我也创建了类:

public class ARepository:BaseRepository<A> {
// Implementation of A's queries and specific db operations
}

这是我的EFUnitOfWork类:

public class EFUnitOfWork : IUnitOfWork, IDisposable
{
    public ObjectContext Context { get; private set; }

    public EFUnitOfWork(ObjectContext context)
    {
        Context = context;
        context.ContextOptions.LazyLoadingEnabled = true;
    }

    public void Commit()
    {
        Context.SaveChanges();
    }

    public void Dispose()
    {
        if (Context != null)
        {
            Context.Dispose();
        }
        GC.SuppressFinalize(this);
    }
}

和UnitOfWork类:

public static class UnitOfWork
{
    private const string HTTPCONTEXTKEY = "MyProj.Domain.Business.Repository.HttpContext.Key";

    private static IUnitOfWorkFactory _unitOfWorkFactory;
    private static readonly Hashtable _threads = new Hashtable();

    public static void Commit()
    {
        IUnitOfWork unitOfWork = GetUnitOfWork();
        if (unitOfWork != null)
        {
            unitOfWork.Commit();
        }
    }

    public static IUnitOfWork Current 
    {
        get
        {
            IUnitOfWork unitOfWork = GetUnitOfWork();
            if (unitOfWork == null)
            {
                _unitOfWorkFactory = ObjectFactory.GetInstance<IUnitOfWorkFactory>();
                unitOfWork = _unitOfWorkFactory.Create();
                SaveUnitOfWork(unitOfWork);
            }
            return unitOfWork;
        }
    }

    private static IUnitOfWork GetUnitOfWork()
    {
        if (HttpContext.Current != null)
        {
            if (HttpContext.Current.Items.Contains(HTTPCONTEXTKEY))
            {
                return (IUnitOfWork)HttpContext.Current.Items[HTTPCONTEXTKEY];
            }
            return null;
        }
        else
        {
            Thread thread = Thread.CurrentThread;
            if (string.IsNullOrEmpty(thread.Name))
            {
                thread.Name = Guid.NewGuid().ToString();
                return null;
            }
            else
            {
                lock (_threads.SyncRoot)
                {
                    return (IUnitOfWork)_threads[Thread.CurrentThread.Name];
                }
            }
        }
    }

    private static void SaveUnitOfWork(IUnitOfWork unitOfWork)
    {
        if (HttpContext.Current != null)
        {
            HttpContext.Current.Items[HTTPCONTEXTKEY] = unitOfWork;
        }
        else
        {
            lock(_threads.SyncRoot)
            {
                _threads[Thread.CurrentThread.Name] = unitOfWork;
            }
        }
    }
}

以下是我如何使用它:

 public class TaskPriceRepository : BaseRepository<TaskPrice>
    {
        public void Set(TaskPrice entity)
        {
            TaskPrice taskPrice = GetQuery().SingleOrDefault(x => x.TaskId == entity.TaskId);
            if (taskPrice != null)
            {
                CommonUtils.CopyObject<TaskPrice>(entity, ref taskPrice);
            }
            else
            {
                this.Insert(entity);
            }
        }
    }

public class BranchRepository : BaseRepository<Branch>
{
    public IList<Branch> GetBranchesList(Guid companyId, long? branchId, string branchName)
    {
        return Repository.GetQuery().
            Where(b => companyId == b.CompanyId).
            Where(b => b.IsDeleted == false).
            Where(b => !branchId.HasValue || b.BranchId.Equals(branchId.Value)).
            Where(b => branchName == null || b.BranchName.Contains(branchName)).
            ToList();
    }
}

[WebMethod]
public void SetTaskPrice(TaskPriceDTO taskPrice)
{
    TaskPrice tp = taskPrice.ToEntity();
    TaskPriceRepository rep = new TaskPriceRepository();
    rep.Set(tp);
    UnitOfWork.Commit();
}

[WebMethod]
public IList<Branch> GetBranchesList()
{
    BranchRepository rep = new BranchRepository();
    return rep.GetBranchesList(m_User.UserCompany.CompanyId, null, null).ToList();
}

我希望这足以帮助我解决问题.谢谢.

UPDATE 2
还有UnitOfWorkFactory初始化UnitOfWork:

public class UnitOfWorkFactory : IUnitOfWorkFactory
{
    private static Func<ObjectContext> _objectContextDelegate;
    private static readonly Object _lockObject = new object();

    public static void SetObjectContext(Func<ObjectContext> objectContextDelegate)
    {
        _objectContextDelegate = objectContextDelegate;
    }

    public IUnitOfWork Create()
    {
        ObjectContext context;
        lock (_lockObject)
        {
             context = _objectContextDelegate();
        }
        return new EFUnitOfWork(context);
    }
}

为了使用它,在应用程序启动时我使用了structuremap:

  ObjectFactory.Initialize(x =>
        {
            x.For<IUnitOfWorkFactory>().Use<UnitOfWorkFactory>();
            x.For(typeof(IRepository<>)).Use(typeof(Repository<>));
        });

Answer 1

我有预感你没有处理上下文.
我建议你在与数据库交互时处理上下文.

using创建上下文时使用语句.

[编辑]

据我所知,你缓存并不处理你的EFUnitOfWork对象.它是一次性的,这是正确的,但我没有看到什么时候被称为一次性.好像你对所有应用程序运行时的上下文都有一个引用.
此外,您为每个线程创建并保留一个上下文,这将使其更糟糕.

我不能告诉你肯定你应该把Dispose或using,因为我不知道惯例.
您可以将它放在您的Commit方法中,但我不知道Commit在数据库交互会话期间是否只调用一次.

此外,您的设计可能过于复杂.

如果我是你我会:

• 找到使用当前代码处理上下文的方法,作为短期解决方案
• 简化设计,作为长期解决方案

如果我有时间,我会马上做长期解决方案.
但同样,我无法判断您的设计的复杂性是否合理,因为我不知道您的应用程序有多大,它的功能和要求是什么.

Answer 2

我想到了几件事：

• 您可能不会处理ObjectContext。确保所有数据库代码都在using(var context = CreateObjectContext())块内
• 您具有N层体系结构，并且正在将实体从数据访问层传递到上层，而没有从ObjectContext中分离实体。您需要调用ObjectContext.Detach（...）
• 您很可能返回完整的实体集合，而不是为单个Get操作返回单个实体。例如，您有类似的查询from customer in context.Customers select customer而不是from customer in context.Customers select customer.FirstOrDefault()

我很难使Entity Framework在N层应用程序中工作。它只是不适合在N层应用程序中使用。只有EF 4.0。您可以阅读有关使EF 3在N层应用程序中运行的所有经历。

http://www.codeproject.com/KB/linq/ef.aspx

这回答了你的问题了吗？