Imported Upstream version 4.6.0.125

Former-commit-id: a2155e9bd80020e49e72e86c44da02a8ac0e57a4

mcs/class/referencesource/System.Data.Entity/System/Data/Objects/Internal/BaseEntityWrapper.cs

@@ -0,0 +1,236 @@
+//---------------------------------------------------------------------
+// <copyright file="BaseEntityWrapper.cs" company="Microsoft">
+//      Copyright (c) Microsoft Corporation.  All rights reserved.
+// </copyright>
+//
+// @owner       [....]
+// @backupOwner [....]
+//---------------------------------------------------------------------
+using System.Collections;
+using System.Data.Objects.DataClasses;
+using System.Diagnostics;
+using System.Reflection;
+using System.Data.Metadata.Edm;
+
+namespace System.Data.Objects.Internal
+{
+    /// <summary>
+    /// Base class containing common code for different implementations of the IEntityWrapper
+    /// interface.  Generally speaking, operations involving the ObjectContext, RelationshipManager
+    /// and raw Entity are handled through this class.
+    /// </summary>
+    /// <typeparam name="TEntity">The type of entity wrapped</typeparam>
+    internal abstract class BaseEntityWrapper<TEntity> : IEntityWrapper
+    {
+        // This enum allows boolean flags to be added to the wrapper without introducing a new field
+        // for each one.  This helps keep the wrapper memory footprint small, which is important
+        // in some high-performance NoTracking cases.
+        [Flags]
+        private enum WrapperFlags
+        {
+            None = 0,
+            NoTracking = 1,
+            InitializingRelatedEnds = 2,
+        }
+
+        private readonly RelationshipManager _relationshipManager;
+        private Type _identityType;
+        private WrapperFlags _flags;
+
+        /// <summary>
+        /// Constructs a wrapper for the given entity and its associated RelationshipManager.
+        /// </summary>
+        /// <param name="entity">The entity to be wrapped</param>
+        /// <param name="relationshipManager">the RelationshipManager associated with this entity</param>
+        protected BaseEntityWrapper(TEntity entity, RelationshipManager relationshipManager)
+        {
+            Debug.Assert(!(entity is IEntityWrapper), "Object is an IEntityWrapper instance instead of the raw entity.");
+            Debug.Assert(entity != null, "Factory should ensure wrapped entity here is never null.");
+            if (relationshipManager == null)
+            {
+                throw EntityUtil.UnexpectedNullRelationshipManager();
+            }
+            _relationshipManager = relationshipManager;
+        }
+
+        /// <summary>
+        /// Constructs a wrapper as part of the materialization process.  This constructor is only used
+        /// during materialization where it is known that the entity being wrapped is newly constructed.
+        /// This means that some checks are not performed that might be needed when thw wrapper is
+        /// created at other times, and information such as the identity type is passed in because
+        /// it is readily available in the materializer.
+        /// </summary>
+        /// <param name="entity">The entity to wrap</param>
+        /// <param name="relationshipManager">The RelationshipManager associated with this entity</param>
+        /// <param name="entitySet">The entity set, or null if none is known</param>
+        /// <param name="context">The context to which the entity should be attached</param>
+        /// <param name="mergeOption">NoTracking for non-tracked entities, AppendOnly otherwise</param>
+        /// <param name="identityType">The type of the entity ignoring any possible proxy type</param>
+        protected BaseEntityWrapper(TEntity entity, RelationshipManager relationshipManager, EntitySet entitySet, ObjectContext context, MergeOption mergeOption, Type identityType)
+        {
+            Debug.Assert(!(entity is IEntityWrapper), "Object is an IEntityWrapper instance instead of the raw entity.");
+            Debug.Assert(entity != null, "Factory should ensure wrapped entity here is never null.");
+            if (relationshipManager == null)
+            {
+                throw EntityUtil.UnexpectedNullRelationshipManager();
+            }
+            _identityType = identityType;
+            _relationshipManager = relationshipManager;
+            RelationshipManager.SetWrappedOwner(this, entity);
+            if (entitySet != null)
+            {
+                Context = context;
+                MergeOption = mergeOption;
+                RelationshipManager.AttachContextToRelatedEnds(context, entitySet, mergeOption);
+            }
+            
+        }
+
+        // See IEntityWrapper documentation
+        public RelationshipManager RelationshipManager
+        {
+            get
+            {
+                return _relationshipManager;
+            }
+        }
+
+        // See IEntityWrapper documentation
+        public ObjectContext Context
+        {
+            get;
+            set;
+        }
+
+        // See IEntityWrapper documentation
+        public MergeOption MergeOption
+        {
+            get
+            {
+                return (_flags & WrapperFlags.NoTracking) != 0 ? MergeOption.NoTracking : MergeOption.AppendOnly;
+            }
+            private set
+            {
+                Debug.Assert(value == MergeOption.AppendOnly || value == MergeOption.NoTracking, "Merge option must be one of NoTracking or AppendOnly.");
+                if (value == MergeOption.NoTracking)
+                {
+                    _flags |= WrapperFlags.NoTracking;
+                }
+                else
+                {
+                    _flags &= ~WrapperFlags.NoTracking;
+                }
+            }
+        }
+
+        // See IEntityWrapper documentation
+        public bool InitializingProxyRelatedEnds
+        {
+            get
+            {
+                return (_flags & WrapperFlags.InitializingRelatedEnds) != 0;
+            }
+            set
+            {
+                if (value)
+                {
+                    _flags |= WrapperFlags.InitializingRelatedEnds;
+                }
+                else
+                {
+                    _flags &= ~WrapperFlags.InitializingRelatedEnds;
+                }
+            }
+        }
+
+        // See IEntityWrapper documentation
+        public void AttachContext(ObjectContext context, EntitySet entitySet, MergeOption mergeOption)
+        {
+            Debug.Assert(null != context, "context");
+            Context = context;
+            MergeOption = mergeOption;
+            if (entitySet != null)
+            {
+                RelationshipManager.AttachContextToRelatedEnds(context, entitySet, mergeOption);
+            }
+        }
+
+        // See IEntityWrapper documentation
+        public void ResetContext(ObjectContext context, EntitySet entitySet, MergeOption mergeOption)
+        {
+            Debug.Assert(null != entitySet, "entitySet should not be null");
+            Debug.Assert(null != context, "context");
+            Debug.Assert(MergeOption.NoTracking == mergeOption ||
+                         MergeOption.AppendOnly == mergeOption,
+                         "mergeOption");
+
+            if (!object.ReferenceEquals(Context, context))
+            {
+                Context = context;
+                MergeOption = mergeOption;
+                RelationshipManager.ResetContextOnRelatedEnds(context, entitySet, mergeOption);
+            }
+        }
+
+        // See IEntityWrapper documentation
+        public void DetachContext()
+        {
+            if (Context != null &&
+                Context.ObjectStateManager.TransactionManager.IsAttachTracking &&
+                Context.ObjectStateManager.TransactionManager.OriginalMergeOption == MergeOption.NoTracking)
+            {
+                // If AttachTo() failed while attaching graph retrieved with NoTracking option,
+                // we don't want to clear the Context property of the wrapped entity
+                MergeOption = MergeOption.NoTracking;
+            }
+            else
+            {
+                Context = null;
+            }
+
+            RelationshipManager.DetachContextFromRelatedEnds();
+        }
+
+        // See IEntityWrapper documentation
+        public EntityEntry ObjectStateEntry
+        {
+            get;
+            set;
+        }
+
+        // See IEntityWrapper documentation
+        public Type IdentityType
+        {
+            get
+            {
+                if (_identityType == null)
+                {
+                    _identityType = EntityUtil.GetEntityIdentityType(typeof(TEntity));
+                }
+                return _identityType;
+            }
+        }
+
+        // All these methods defined by IEntityWrapper
+        public abstract void EnsureCollectionNotNull(RelatedEnd relatedEnd);
+        public abstract EntityKey EntityKey { get; set; }
+        public abstract bool OwnsRelationshipManager
+        {
+            get;
+        }
+        public abstract EntityKey GetEntityKeyFromEntity();
+        public abstract void SetChangeTracker(IEntityChangeTracker changeTracker);
+        public abstract void TakeSnapshot(EntityEntry entry);
+        public abstract void TakeSnapshotOfRelationships(EntityEntry entry);
+        public abstract object GetNavigationPropertyValue(RelatedEnd relatedEnd);
+        public abstract void SetNavigationPropertyValue(RelatedEnd relatedEnd, object value);
+        public abstract void RemoveNavigationPropertyValue(RelatedEnd relatedEnd, object value);
+        public abstract void CollectionAdd(RelatedEnd relatedEnd, object value);
+        public abstract bool CollectionRemove(RelatedEnd relatedEnd, object value);
+        public abstract object Entity { get; }
+        public abstract TEntity TypedEntity { get; }
+        public abstract void SetCurrentValue(EntityEntry entry, StateManagerMemberMetadata member, int ordinal, object target, object value);
+        public abstract void UpdateCurrentValueRecord(object value, EntityEntry entry);
+        public abstract bool RequiresRelationshipChangeTracking { get; }
+    }
+}

mcs/class/referencesource/System.Data.Entity/System/Data/Objects/Internal/ComplexTypeMaterializer.cs

@@ -0,0 +1,180 @@
+//---------------------------------------------------------------------
+// <copyright file="ComplexTypeMaterializer.cs" company="Microsoft">
+//      Copyright (c) Microsoft Corporation.  All rights reserved.
+// </copyright>
+//
+// @owner       [....]
+// @backupOwner [....]
+//---------------------------------------------------------------------
+
+using System.Data.Metadata.Edm;
+using System.Data.Common;
+using System.Diagnostics;
+using System.Data.Mapping;
+namespace System.Data.Objects.Internal
+{
+    /// <summary>
+    /// Supports materialization of complex type instances from records. Used
+    /// by the ObjectStateManager.
+    /// </summary>
+    internal class ComplexTypeMaterializer
+    {
+        private readonly MetadataWorkspace _workspace;
+        private const int MaxPlanCount = 4;
+        private Plan[] _lastPlans;
+        private int _lastPlanIndex;
+
+        internal ComplexTypeMaterializer(MetadataWorkspace workspace)
+        {
+            _workspace = workspace;
+        }
+
+        internal object CreateComplex(IExtendedDataRecord record, DataRecordInfo recordInfo, object result)
+        {
+            Debug.Assert(null != record, "null IExtendedDataRecord");
+            Debug.Assert(null != recordInfo, "null DataRecordInfo");
+            Debug.Assert(null != recordInfo.RecordType, "null TypeUsage");
+            Debug.Assert(null != recordInfo.RecordType.EdmType, "null EdmType");
+
+            Debug.Assert(Helper.IsEntityType(recordInfo.RecordType.EdmType) ||
+                         Helper.IsComplexType(recordInfo.RecordType.EdmType),
+                         "not EntityType or ComplexType");
+
+            Plan plan = GetPlan(record, recordInfo);
+            if (null == result)
+            {
+                result = ((Func<object>)plan.ClrType)();
+            }
+            SetProperties(record, result, plan.Properties);
+            return result;
+        }
+
+        private void SetProperties(IExtendedDataRecord record, object result, PlanEdmProperty[] properties)
+        {
+            Debug.Assert(null != record, "null IExtendedDataRecord");
+            Debug.Assert(null != result, "null object");
+            Debug.Assert(null != properties, "null object");
+
+            for (int i = 0; i < properties.Length; ++i)
+            {
+                if (null != properties[i].GetExistingComplex)
+                {
+                    object existing = properties[i].GetExistingComplex(result);
+                    object obj = CreateComplexRecursive(record.GetValue(properties[i].Ordinal), existing);
+                    if (null == existing)
+                    {
+                        properties[i].ClrProperty(result, obj);
+                    }
+                }
+                else
+                {
+                    properties[i].ClrProperty(result,
+                        ConvertDBNull(
+                            record.GetValue(
+                                properties[i].Ordinal)));
+                }
+            }
+        }
+
+        private static object ConvertDBNull(object value)
+        {
+            return ((DBNull.Value != value) ? value : null);
+        }
+
+        private object CreateComplexRecursive(object record, object existing)
+        {
+            return ((DBNull.Value != record) ? CreateComplexRecursive((IExtendedDataRecord)record, existing) : existing);
+        }
+
+        private object CreateComplexRecursive(IExtendedDataRecord record, object existing)
+        {
+            return CreateComplex(record, record.DataRecordInfo, existing);
+        }
+
+        private Plan GetPlan(IExtendedDataRecord record, DataRecordInfo recordInfo)
+        {
+            Debug.Assert(null != record, "null IExtendedDataRecord");
+            Debug.Assert(null != recordInfo, "null DataRecordInfo");
+            Debug.Assert(null != recordInfo.RecordType, "null TypeUsage");
+
+            Plan[] plans = _lastPlans ?? (_lastPlans = new Plan[MaxPlanCount]);
+
+            // find an existing plan in circular buffer
+            int index = _lastPlanIndex - 1;
+            for (int i = 0; i < MaxPlanCount; ++i)
+            {
+                index = (index + 1) % MaxPlanCount;
+                if (null == plans[index])
+                {
+                    break;
+                }
+                if (plans[index].Key == recordInfo.RecordType)
+                {
+                    _lastPlanIndex = index;
+                    return plans[index];
+                }
+            }
+            Debug.Assert(0 <= index, "negative index");
+            Debug.Assert(index != _lastPlanIndex || (null == plans[index]), "index wrapped around");
+
+            // create a new plan
+            ObjectTypeMapping mapping = System.Data.Common.Internal.Materialization.Util.GetObjectMapping(recordInfo.RecordType.EdmType, _workspace);
+            Debug.Assert(null != mapping, "null ObjectTypeMapping");
+
+            Debug.Assert(Helper.IsComplexType(recordInfo.RecordType.EdmType),
+                         "IExtendedDataRecord is not ComplexType");
+
+            _lastPlanIndex = index;
+            plans[index] = new Plan(recordInfo.RecordType, mapping, recordInfo.FieldMetadata);
+            return plans[index];
+        }
+
+        private sealed class Plan
+        {
+            internal readonly TypeUsage Key;
+            internal readonly Delegate ClrType;
+            internal readonly PlanEdmProperty[] Properties;
+
+            internal Plan(TypeUsage key, ObjectTypeMapping mapping, System.Collections.ObjectModel.ReadOnlyCollection<FieldMetadata> fields)
+            {
+                Debug.Assert(null != mapping, "null ObjectTypeMapping");
+                Debug.Assert(null != fields, "null FieldMetadata");
+
+                Key = key;
+                Debug.Assert(!Helper.IsEntityType(mapping.ClrType), "Expecting complex type");
+                ClrType = LightweightCodeGenerator.GetConstructorDelegateForType((ClrComplexType)mapping.ClrType);
+                Properties = new PlanEdmProperty[fields.Count];
+
+                int lastOrdinal = -1;
+                for (int i = 0; i < Properties.Length; ++i)
+                {
+                    FieldMetadata field = fields[i];
+
+                    Debug.Assert(unchecked((uint)field.Ordinal) < unchecked((uint)fields.Count), "FieldMetadata.Ordinal out of range of Fields.Count");
+                    Debug.Assert(lastOrdinal < field.Ordinal, "FieldMetadata.Ordinal is not increasing");
+                    lastOrdinal = field.Ordinal;
+
+                    Properties[i] = new PlanEdmProperty(lastOrdinal, mapping.GetPropertyMap(field.FieldType.Name).ClrProperty);
+                }
+            }
+        }
+
+        private struct PlanEdmProperty
+        {
+            internal readonly int Ordinal;
+            internal readonly Func<object, object> GetExistingComplex;
+            internal readonly Action<object, object> ClrProperty;
+
+            internal PlanEdmProperty(int ordinal, EdmProperty property)
+            {
+                Debug.Assert(0 <= ordinal, "negative ordinal");
+                Debug.Assert(null != property, "unsupported shadow state");
+
+                this.Ordinal = ordinal;
+                this.GetExistingComplex = Helper.IsComplexType(property.TypeUsage.EdmType)
+                    ? LightweightCodeGenerator.GetGetterDelegateForProperty(property) : null;
+                this.ClrProperty = LightweightCodeGenerator.GetSetterDelegateForProperty(property);
+            }
+        }
+    }
+}

mcs/class/referencesource/System.Data.Entity/System/Data/Objects/Internal/EntityProxyTypeInfo.cs

@@ -0,0 +1,220 @@
+//---------------------------------------------------------------------
+// <copyright file="EntityProxyTypeInfo.cs" company="Microsoft">
+//      Copyright (c) Microsoft Corporation.  All rights reserved.
+// </copyright>
+//
+// @owner       [....]
+// @backupOwner [....]
+//---------------------------------------------------------------------
+
+namespace System.Data.Objects.Internal
+{
+    using System;
+    using System.Collections.Generic;
+    using System.Data.Metadata.Edm;
+    using System.Diagnostics;
+    using System.Linq;
+    using System.Linq.Expressions;
+    using System.Reflection;
+    using System.Reflection.Emit;
+
+    /// <summary>
+    /// Contains the Type of a proxy class, along with any behaviors associated with that proxy Type.
+    /// </summary>
+    internal sealed class EntityProxyTypeInfo
+    {
+        private readonly Type _proxyType;
+        private readonly ClrEntityType _entityType;        // The OSpace entity type that created this proxy info
+
+        internal const string EntityWrapperFieldName = "_entityWrapper";
+        private const string InitializeEntityCollectionsName = "InitializeEntityCollections";
+        private readonly DynamicMethod _initializeCollections;
+
+        private readonly Func<object, string, object> _baseGetter;
+        private readonly HashSet<string> _propertiesWithBaseGetter;
+        private readonly Action<object, string, object> _baseSetter;
+        private readonly HashSet<string> _propertiesWithBaseSetter;
+        private readonly Func<object, object> Proxy_GetEntityWrapper;
+        private readonly Func<object, object, object> Proxy_SetEntityWrapper; // IEntityWrapper Func(object proxy, IEntityWrapper value)
+
+        private readonly Func<object> _createObject;
+
+        // An index of relationship metadata strings to an AssociationType
+        // This is used when metadata is not otherwise available to the proxy
+        private readonly Dictionary<Tuple<string, string>, AssociationType> _navigationPropertyAssociationTypes;
+
+        internal EntityProxyTypeInfo(Type proxyType, ClrEntityType ospaceEntityType, DynamicMethod initializeCollections, List<PropertyInfo> baseGetters, List<PropertyInfo> baseSetters)
+        {
+            Debug.Assert(proxyType != null, "proxyType must be non-null");
+
+            _proxyType = proxyType;
+            _entityType = ospaceEntityType;
+
+            _initializeCollections = initializeCollections;
+
+            _navigationPropertyAssociationTypes = new Dictionary<Tuple<string, string>, AssociationType>();
+            foreach (NavigationProperty navigationProperty in ospaceEntityType.NavigationProperties)
+            {
+                _navigationPropertyAssociationTypes.Add(
+                    new Tuple<string, string>(
+                        navigationProperty.RelationshipType.FullName,
+                        navigationProperty.ToEndMember.Name),
+                    (AssociationType)navigationProperty.RelationshipType);
+
+                if (navigationProperty.RelationshipType.Name != navigationProperty.RelationshipType.FullName)
+                {
+                    // Sometimes there isn't enough metadata to have a container name
+                    // Default codegen doesn't qualify names
+                    _navigationPropertyAssociationTypes.Add(
+                        new Tuple<string, string>(
+                            navigationProperty.RelationshipType.Name,
+                            navigationProperty.ToEndMember.Name),
+                        (AssociationType)navigationProperty.RelationshipType);
+                }
+            }
+
+            FieldInfo entityWrapperField = proxyType.GetField(EntityWrapperFieldName, BindingFlags.DeclaredOnly | BindingFlags.NonPublic | BindingFlags.Public | BindingFlags.Instance);
+
+            ParameterExpression Object_Parameter = Expression.Parameter(typeof(object), "proxy");
+            ParameterExpression Value_Parameter = Expression.Parameter(typeof(object), "value");
+
+            Debug.Assert(entityWrapperField != null, "entityWrapperField does not exist");   
+
+            // Create the Wrapper Getter
+            Expression<Func<object, object>> lambda = Expression.Lambda<Func<object, object>>(
+                    Expression.Field(
+                        Expression.Convert(Object_Parameter, entityWrapperField.DeclaringType), entityWrapperField),
+                        Object_Parameter);
+            Func<object, object> getEntityWrapperDelegate = lambda.Compile();
+            Proxy_GetEntityWrapper = (object proxy) =>
+            {
+                // This code validates that the wrapper points to the proxy that holds the wrapper.
+                // This guards against mischief by switching this wrapper out for another one obtained
+                // from a different object.
+                IEntityWrapper wrapper = ((IEntityWrapper)getEntityWrapperDelegate(proxy));
+                if (wrapper != null && !object.ReferenceEquals(wrapper.Entity, proxy))
+                {
+                    throw new InvalidOperationException(System.Data.Entity.Strings.EntityProxyTypeInfo_ProxyHasWrongWrapper);
+                }
+                return wrapper;
+            };
+
+            // Create the Wrapper setter
+            Proxy_SetEntityWrapper = Expression.Lambda<Func<object, object, object>>(
+                    Expression.Assign(
+                        Expression.Field(
+                            Expression.Convert(Object_Parameter, entityWrapperField.DeclaringType),
+                            entityWrapperField),
+                        Value_Parameter),
+                    Object_Parameter, Value_Parameter).Compile();
+
+
+            ParameterExpression PropertyName_Parameter = Expression.Parameter(typeof(string), "propertyName");
+            MethodInfo baseGetterMethod = proxyType.GetMethod("GetBasePropertyValue", BindingFlags.Public | BindingFlags.Instance, null, new Type[] { typeof(string) }, null);
+            if (baseGetterMethod != null)
+            {
+                _baseGetter = Expression.Lambda<Func<object, string, object>>(
+                    Expression.Call(Expression.Convert(Object_Parameter, proxyType), baseGetterMethod, PropertyName_Parameter),
+                    Object_Parameter, PropertyName_Parameter).Compile();
+            }
+
+            ParameterExpression PropertyValue_Parameter = Expression.Parameter(typeof(object), "propertyName");
+            MethodInfo baseSetterMethod = proxyType.GetMethod("SetBasePropertyValue", BindingFlags.Public | BindingFlags.Instance, null, new Type[] { typeof(string), typeof(object) }, null);
+            if (baseSetterMethod != null)
+            {
+                _baseSetter = Expression.Lambda<Action<object, string, object>>(
+                        Expression.Call(Expression.Convert(Object_Parameter, proxyType), baseSetterMethod, PropertyName_Parameter, PropertyValue_Parameter),
+                        Object_Parameter, PropertyName_Parameter, PropertyValue_Parameter).Compile();
+            }
+
+            _propertiesWithBaseGetter = new HashSet<string>(baseGetters.Select(p => p.Name));
+            _propertiesWithBaseSetter = new HashSet<string>(baseSetters.Select(p => p.Name));
+
+            _createObject = LightweightCodeGenerator.CreateConstructor(proxyType) as Func<object>;
+        }
+
+        internal object CreateProxyObject()
+        {
+            return _createObject();
+        }
+
+        internal Type ProxyType
+        {
+            get { return _proxyType; }
+        }
+
+        internal DynamicMethod InitializeEntityCollections
+        {
+            get { return _initializeCollections; }
+        }
+
+        public Func<object, string, object> BaseGetter
+        {
+            get { return _baseGetter; }
+        }
+
+        public bool ContainsBaseGetter(string propertyName)
+        {
+            return BaseGetter != null && _propertiesWithBaseGetter.Contains(propertyName);
+        }
+
+        public bool ContainsBaseSetter(string propertyName)
+        {
+            return BaseSetter != null && _propertiesWithBaseSetter.Contains(propertyName);
+        }
+
+        public Action<object, string, object> BaseSetter
+        {
+            get { return _baseSetter; }
+        }
+
+        public bool TryGetNavigationPropertyAssociationType(string relationshipName, string targetRoleName, out AssociationType associationType)
+        {
+            return _navigationPropertyAssociationTypes.TryGetValue(new Tuple<string, string>(relationshipName, targetRoleName), out associationType);
+        }
+
+        public void ValidateType(ClrEntityType ospaceEntityType)
+        {
+            if (ospaceEntityType != _entityType && ospaceEntityType.HashedDescription != _entityType.HashedDescription)
+            {
+                Debug.Assert(ospaceEntityType.ClrType == _entityType.ClrType);
+                throw EntityUtil.DuplicateTypeForProxyType(ospaceEntityType.ClrType);
+            }
+        }
+
+        #region Wrapper on the Proxy
+
+        /// <summary>
+        /// Set the proxy object's private entity wrapper field value to the specified entity wrapper object.
+        /// The proxy object (representing the wrapped entity) is retrieved from the wrapper itself.
+        /// </summary>
+        /// <param name="wrapper">Wrapper object to be referenced by the proxy.</param>
+        /// <returns>
+        /// The supplied entity wrapper.
+        /// This is done so that this method can be more easily composed within lambda expressions (such as in the materializer).
+        /// </returns>
+        internal IEntityWrapper SetEntityWrapper(IEntityWrapper wrapper)
+        {
+            Debug.Assert(wrapper != null, "wrapper must be non-null");
+            Debug.Assert(wrapper.Entity != null, "proxy must be non-null");
+            return Proxy_SetEntityWrapper(wrapper.Entity, wrapper) as IEntityWrapper;
+        }
+
+        /// <summary>
+        /// Gets the proxy object's entity wrapper field value
+        /// </summary>
+        /// <param name="entity"></param>
+        /// <returns></returns>
+        internal IEntityWrapper GetEntityWrapper(object entity)
+        {
+            return Proxy_GetEntityWrapper(entity) as IEntityWrapper;
+        }
+
+        internal Func<object, object> EntityWrapperDelegate
+        {
+            get { return Proxy_GetEntityWrapper; }
+        }
+
+        #endregion
+    }
+}

mcs/class/referencesource/System.Data.Entity/System/Data/Objects/Internal/EntitySqlQueryState.cs

@@ -0,0 +1,270 @@
+//---------------------------------------------------------------------
+// <copyright file="EntitySqlQueryState.cs" company="Microsoft">
+//      Copyright (c) Microsoft Corporation.  All rights reserved.
+// </copyright>
+//
+// @owner  [....]
+//---------------------------------------------------------------------
+
+namespace System.Data.Objects
+{
+    using System.Collections.Generic;
+    using System.Data.Common.CommandTrees;
+    using System.Data.Common.CommandTrees.ExpressionBuilder;
+    using System.Data.Common.EntitySql;
+    using System.Data.Common.QueryCache;
+    using System.Data.Metadata.Edm;
+    using System.Data.Objects.Internal;
+    using System.Diagnostics;
+
+    /// <summary>
+    /// ObjectQueryState based on Entity-SQL query text.
+    /// </summary>
+    internal sealed class EntitySqlQueryState : ObjectQueryState
+    {
+        /// <summary>
+        /// The Entity-SQL text that defines the query.
+        /// </summary>
+        /// <remarks>
+        /// It is important that this field is readonly for consistency reasons wrt <see cref="_queryExpression"/>.
+        /// If this field becomes read-write, then write should be allowed only when <see cref="_queryExpression"/> is null, 
+        /// or there should be a mechanism keeping both fields consistent.
+        /// </remarks>
+        private readonly string _queryText;
+
+        /// <summary>
+        /// Optional <see cref="DbExpression"/> that defines the query. Must be semantically equal to the <see cref="_queryText"/>.
+        /// </summary>
+        /// <remarks>
+        /// It is important that this field is readonly for consistency reasons wrt <see cref="_queryText"/>.
+        /// If this field becomes read-write, then there should be a mechanism keeping both fields consistent.
+        /// </remarks>
+        private readonly DbExpression _queryExpression;
+
+        /// <summary>
+        ///     Can a Limit subclause be appended to the text of this query?
+        /// </summary>
+        private readonly bool _allowsLimit;
+
+        /// <summary>
+        /// Initializes a new query EntitySqlQueryState instance.
+        /// </summary>
+        /// <param name="context">
+        ///     The ObjectContext containing the metadata workspace the query was
+        ///     built against, the connection on which to execute the query, and the
+        ///     cache to store the results in. Must not be null.
+        /// </param>
+        /// <param name="commandText">
+        ///     The Entity-SQL text of the query
+        /// </param>
+        /// <param name="mergeOption">
+        ///     The merge option to use when retrieving results if an explicit merge option is not specified
+        /// </param>
+        internal EntitySqlQueryState(Type elementType, string commandText, bool allowsLimit, ObjectContext context, ObjectParameterCollection parameters, Span span)
+            : this(elementType, commandText, /*expression*/ null, allowsLimit, context, parameters, span)
+        { }
+        
+        /// <summary>
+        /// Initializes a new query EntitySqlQueryState instance.
+        /// </summary>
+        /// <param name="context">
+        ///     The ObjectContext containing the metadata workspace the query was
+        ///     built against, the connection on which to execute the query, and the
+        ///     cache to store the results in. Must not be null.
+        /// </param>
+        /// <param name="commandText">
+        ///     The Entity-SQL text of the query
+        /// </param>
+        /// <param name="expression">
+        ///     Optional <see cref="DbExpression"/> that defines the query. Must be semantically equal to the <paramref name="commandText"/>.
+        /// </param>
+        /// <param name="mergeOption">
+        ///     The merge option to use when retrieving results if an explicit merge option is not specified
+        /// </param>
+        internal EntitySqlQueryState(Type elementType, string commandText, DbExpression expression, bool allowsLimit, ObjectContext context, ObjectParameterCollection parameters, Span span)
+            : base(elementType, context, parameters, span)
+        {
+            EntityUtil.CheckArgumentNull(commandText, "commandText");
+            if (string.IsNullOrEmpty(commandText))
+            {
+                throw EntityUtil.Argument(System.Data.Entity.Strings.ObjectQuery_InvalidEmptyQuery, "commandText");
+            }
+
+            _queryText = commandText;
+            _queryExpression = expression;
+            _allowsLimit = allowsLimit;
+        }
+
+        /// <summary>
+        ///     Determines whether or not the current query is a 'Skip' or 'Sort' operation
+        ///     and so would allow a 'Limit' clause to be appended to the current query text.
+        /// </summary>
+        /// <returns>
+        ///     <c>True</c> if the current query is a Skip or Sort expression, or a
+        ///     Project expression with a Skip or Sort expression input.
+        /// </returns>
+        internal bool AllowsLimitSubclause { get { return _allowsLimit; } }
+
+        /// <summary>
+        /// Always returns the Entity-SQL text of the implemented ObjectQuery.
+        /// </summary>
+        /// <param name="commandText">Always set to the Entity-SQL text of this ObjectQuery.</param>
+        /// <returns>Always returns <c>true</c>.</returns>
+        internal override bool TryGetCommandText(out string commandText)
+        {
+            commandText = this._queryText;
+            return true;
+        }
+
+        internal override bool TryGetExpression(out System.Linq.Expressions.Expression expression)
+        {
+            expression = null;
+            return false;
+        }
+
+        protected override TypeUsage GetResultType()
+        {
+            DbExpression query = this.Parse();
+            return query.ResultType;
+        }
+
+        internal override ObjectQueryState Include<TElementType>(ObjectQuery<TElementType> sourceQuery, string includePath)
+        {
+            ObjectQueryState retState = new EntitySqlQueryState(this.ElementType, _queryText, _queryExpression, _allowsLimit, this.ObjectContext, ObjectParameterCollection.DeepCopy(this.Parameters), Span.IncludeIn(this.Span, includePath));
+            this.ApplySettingsTo(retState);
+            return retState;
+        }
+
+        internal override ObjectQueryExecutionPlan GetExecutionPlan(MergeOption? forMergeOption)
+        {
+            // Metadata is required to generate the execution plan or to retrieve it from the cache.
+            this.ObjectContext.EnsureMetadata();
+
+            // Determine the required merge option, with the following precedence:
+            // 1. The merge option specified to Execute(MergeOption) as forMergeOption.
+            // 2. The merge option set via ObjectQuery.MergeOption.
+            // 3. The global default merge option.
+            MergeOption mergeOption = EnsureMergeOption(forMergeOption, this.UserSpecifiedMergeOption);
+
+            // If a cached plan is present, then it can be reused if it has the required merge option
+            // (since span and parameters cannot change between executions). However, if the cached
+            // plan does not have the required merge option we proceed as if it were not present.
+            ObjectQueryExecutionPlan plan = this._cachedPlan;
+            if (plan != null)
+            {
+                if (plan.MergeOption == mergeOption)
+                {
+                    return plan;
+                }
+                else
+                {
+                    plan = null;
+                }
+            }
+
+            // There is no cached plan (or it was cleared), so the execution plan must be retrieved from
+            // the global query cache (if plan caching is enabled) or rebuilt for the required merge option.
+            QueryCacheManager cacheManager = null;
+            EntitySqlQueryCacheKey cacheKey = null;
+            if (this.PlanCachingEnabled)
+            {
+                // Create a new cache key that reflects the current state of the Parameters collection
+                // and the Span object (if any), and uses the specified merge option.
+                cacheKey = new EntitySqlQueryCacheKey(
+                                   this.ObjectContext.DefaultContainerName,
+                                   _queryText,
+                                   (null == this.Parameters ? 0 : this.Parameters.Count),
+                                   (null == this.Parameters ? null : this.Parameters.GetCacheKey()),
+                                   (null == this.Span ? null : this.Span.GetCacheKey()),
+                                   mergeOption,
+                                   this.ElementType);
+
+                cacheManager = this.ObjectContext.MetadataWorkspace.GetQueryCacheManager();
+                ObjectQueryExecutionPlan executionPlan = null;
+                if (cacheManager.TryCacheLookup(cacheKey, out executionPlan))
+                {
+                    plan = executionPlan;
+                }
+            }
+
+            if (plan == null)
+            {
+                // Either caching is not enabled or the execution plan was not found in the cache
+                DbExpression queryExpression = this.Parse();
+                Debug.Assert(queryExpression != null, "EntitySqlQueryState.Parse returned null expression?");
+                DbQueryCommandTree tree = DbQueryCommandTree.FromValidExpression(this.ObjectContext.MetadataWorkspace, DataSpace.CSpace, queryExpression);
+                plan = ObjectQueryExecutionPlan.Prepare(this.ObjectContext, tree, this.ElementType, mergeOption, this.Span, null, DbExpressionBuilder.AliasGenerator);
+
+                // If caching is enabled then update the cache now.
+                // Note: the logic is the same as in ELinqQueryState.
+                if (cacheKey != null)
+                {
+                    var newEntry = new QueryCacheEntry(cacheKey, plan);
+                    QueryCacheEntry foundEntry = null;
+                    if (cacheManager.TryLookupAndAdd(newEntry, out foundEntry))
+                    {
+                        // If TryLookupAndAdd returns 'true' then the entry was already present in the cache when the attempt to add was made.
+                        // In this case the existing execution plan should be used.
+                        plan = (ObjectQueryExecutionPlan)foundEntry.GetTarget();
+                    }
+                }
+            }
+
+            if (this.Parameters != null)
+            {
+                this.Parameters.SetReadOnly(true);
+            }
+
+            // Update the cached plan with the newly retrieved/prepared plan
+            this._cachedPlan = plan;
+
+            // Return the execution plan
+            return plan;
+        }
+
+        internal DbExpression Parse()
+        {
+            if (_queryExpression != null)
+            {
+                return _queryExpression;
+            }
+
+            List<DbParameterReferenceExpression> parameters = null;
+            if (this.Parameters != null)
+            {
+                parameters = new List<DbParameterReferenceExpression>(this.Parameters.Count);
+                foreach (ObjectParameter parameter in this.Parameters)
+                {
+                    TypeUsage typeUsage = parameter.TypeUsage;
+                    if (null == typeUsage)
+                    {
+                        // Since ObjectParameters do not allow users to specify 'facets', make 
+                        // sure that the parameter TypeUsage is not populated with the provider
+                        // default facet values.
+                        this.ObjectContext.Perspective.TryGetTypeByName(
+                                        parameter.MappableType.FullName,
+                                        false /* bIgnoreCase */,
+                                        out typeUsage);
+                    }
+
+                    Debug.Assert(typeUsage != null, "typeUsage != null");
+                    
+                    parameters.Add(typeUsage.Parameter(parameter.Name));
+                }
+            }
+
+            DbLambda lambda =
+                CqlQuery.CompileQueryCommandLambda(
+                    _queryText,                     // Command Text
+                    this.ObjectContext.Perspective, // Perspective
+                    null,                           // Parser options - null indicates 'use default'
+                    parameters,                     // Parameters
+                    null                            // Variables
+                );
+
+            Debug.Assert(lambda.Variables == null || lambda.Variables.Count == 0, "lambda.Variables must be empty");
+
+            return lambda.Body;
+        }
+    }
+}

mcs/class/referencesource/System.Data.Entity/System/Data/Objects/Internal/EntityWithChangeTrackerStrategy.cs

@@ -0,0 +1,66 @@
+//---------------------------------------------------------------------
+// <copyright file="EntityWithChangeTrackerStrategy.cs" company="Microsoft">
+//     Copyright (c) Microsoft Corporation.  All rights reserved.
+// </copyright>
+//---------------------------------------------------------------------
+
+using System;
+using System.Collections.Generic;
+using System.Text;
+using System.Data.Objects.DataClasses;
+using System.Diagnostics;
+
+namespace System.Data.Objects.Internal
+{
+    /// <summary>
+    /// Implementation of the change tracking strategy for entities that support change trackers.
+    /// These are typically entities that implement IEntityWithChangeTracker.
+    /// </summary>
+    internal sealed class EntityWithChangeTrackerStrategy : IChangeTrackingStrategy
+    {
+        private IEntityWithChangeTracker _entity;
+
+        /// <summary>
+        /// Constructs a strategy object that will cause the change tracker to be set onto the
+        /// given object.
+        /// </summary>
+        /// <param name="entity">The object onto which a change tracker will be set</param>
+        public EntityWithChangeTrackerStrategy(IEntityWithChangeTracker entity)
+        {
+            _entity = entity;
+        }
+
+        // See IChangeTrackingStrategy documentation
+        public void SetChangeTracker(IEntityChangeTracker changeTracker)
+        {
+            _entity.SetChangeTracker(changeTracker);
+        }
+
+        // See IChangeTrackingStrategy documentation
+        public void TakeSnapshot(EntityEntry entry)
+        {
+            if (entry != null && entry.RequiresComplexChangeTracking)
+            {
+                entry.TakeSnapshot(true);
+            }
+        }
+
+        // See IChangeTrackingStrategy documentation
+        public void SetCurrentValue(EntityEntry entry, StateManagerMemberMetadata member, int ordinal, object target, object value)
+        {
+            member.SetValue(target, value);
+        }
+
+        // See IChangeTrackingStrategy documentation
+        public void UpdateCurrentValueRecord(object value, EntityEntry entry)
+        {
+            // Has change tracker, but may or may not be a proxy
+            bool isProxy = entry.WrappedEntity.IdentityType != _entity.GetType();
+            entry.UpdateRecordWithoutSetModified(value, entry.CurrentValues);
+            if (isProxy)
+            {
+                entry.DetectChangesInProperties(true);      // detect only complex property changes
+            }
+        }
+    }
+}

mcs/class/referencesource/System.Data.Entity/System/Data/Objects/Internal/EntityWithKeyStrategy.cs

@@ -0,0 +1,50 @@
+//---------------------------------------------------------------------
+// <copyright file="EntityWithKeyStrategy.cs" company="Microsoft">
+//     Copyright (c) Microsoft Corporation.  All rights reserved.
+// </copyright>
+//---------------------------------------------------------------------
+using System;
+using System.Collections.Generic;
+using System.Text;
+using System.Data;
+using System.Data.Objects.DataClasses;
+using System.Diagnostics;
+
+namespace System.Data.Objects.Internal
+{
+    /// <summary>
+    /// Implementor of IEntityKeyStrategy for entities that implement IEntityWithKey.  Getting and setting
+    /// the key is deferred to the entity itself.
+    /// </summary>
+    internal sealed class EntityWithKeyStrategy : IEntityKeyStrategy
+    {
+        private IEntityWithKey _entity;
+
+        /// <summary>
+        /// Creates a strategy object for the given entity.  Keys will be stored in the entity.
+        /// </summary>
+        /// <param name="entity">The entity to use</param>
+        public EntityWithKeyStrategy(IEntityWithKey entity)
+        {
+            _entity = entity;
+        }
+
+        // See IEntityKeyStrategy
+        public EntityKey GetEntityKey()
+        {
+            return _entity.EntityKey;
+        }
+
+        // See IEntityKeyStrategy
+        public void SetEntityKey(EntityKey key)
+        {
+            _entity.EntityKey = key;
+        }
+
+        // See IEntityKeyStrategy
+        public EntityKey GetEntityKeyFromEntity()
+        {
+            return _entity.EntityKey;
+        }
+    }
+}

mcs/class/referencesource/System.Data.Entity/System/Data/Objects/Internal/EntityWrapper.cs

@@ -0,0 +1,323 @@
+//---------------------------------------------------------------------
+// <copyright file="EntityWrapper.cs" company="Microsoft">
+//      Copyright (c) Microsoft Corporation.  All rights reserved.
+// </copyright>
+//
+// @owner       [....]
+// @backupOwner [....]
+//---------------------------------------------------------------------
+using System.Collections;
+using System.Data.Objects.DataClasses;
+using System.Diagnostics;
+using System.Reflection;
+using System.Data.Metadata.Edm;
+
+namespace System.Data.Objects.Internal
+{
+    /// <summary>
+    /// An extension of the EntityWrapper class for entities that are known not to implement
+    /// IEntityWithRelationships.  Using this class causes the RelationshipManager to be created
+    /// independently.
+    /// </summary>
+    /// <typeparam name="TEntity">The type of entity wrapped</typeparam>
+    internal sealed class EntityWrapperWithoutRelationships<TEntity> : EntityWrapper<TEntity>
+    {
+        /// <summary>
+        /// Constructs a wrapper as part of the materialization process.  This constructor is only used
+        /// during materialization where it is known that the entity being wrapped is newly constructed.
+        /// This means that some checks are not performed that might be needed when thw wrapper is
+        /// created at other times, and information such as the identity type is passed in because
+        /// it is readily available in the materializer.
+        /// </summary>
+        /// <param name="entity">The entity to wrap</param>
+        /// <param name="key">The entity's key</param>
+        /// <param name="entitySet">The entity set, or null if none is known</param>
+        /// <param name="context">The context to which the entity should be attached</param>
+        /// <param name="mergeOption">NoTracking for non-tracked entities, AppendOnly otherwise</param>
+        /// <param name="identityType">The type of the entity ignoring any possible proxy type</param>
+        /// <param name="propertyStrategy">A delegate to create the property accesor strategy object</param>
+        /// <param name="changeTrackingStrategy">A delegate to create the change tracking strategy object</param>
+        /// <param name="keyStrategy">A delegate to create the entity key strategy object</param>
+        internal EntityWrapperWithoutRelationships(TEntity entity, EntityKey key, EntitySet entitySet, ObjectContext context, MergeOption mergeOption, Type identityType,
+                                                   Func<object, IPropertyAccessorStrategy> propertyStrategy, Func<object, IChangeTrackingStrategy> changeTrackingStrategy, Func<object, IEntityKeyStrategy> keyStrategy)
+            : base(entity, RelationshipManager.Create(), key, entitySet, context, mergeOption, identityType,
+                   propertyStrategy, changeTrackingStrategy, keyStrategy)
+        {
+        }
+
+        /// <summary>
+        /// Constructs a wrapper for the given entity.
+        /// Note: use EntityWrapperFactory instead of calling this constructor directly.
+        /// </summary>
+        /// <param name="entity">The entity to wrap</param>
+        /// <param name="propertyStrategy">A delegate to create the property accesor strategy object</param>
+        /// <param name="changeTrackingStrategy">A delegate to create the change tracking strategy object</param>
+        /// <param name="keyStrategy">A delegate to create the entity key strategy object</param>
+        internal EntityWrapperWithoutRelationships(TEntity entity, Func<object, IPropertyAccessorStrategy> propertyStrategy, Func<object, IChangeTrackingStrategy> changeTrackingStrategy, Func<object, IEntityKeyStrategy> keyStrategy)
+            : base(entity, RelationshipManager.Create(), propertyStrategy, changeTrackingStrategy, keyStrategy)
+        {
+        }
+
+        public override bool OwnsRelationshipManager
+        {
+            get { return false; }
+        }
+
+        public override void TakeSnapshotOfRelationships(EntityEntry entry)
+        {
+            entry.TakeSnapshotOfRelationships();
+        }
+
+        // See IEntityWrapper documentation
+        public override bool RequiresRelationshipChangeTracking
+        {
+            get { return true; }
+        }
+    }
+
+    /// <summary>
+    /// An extension of the EntityWrapper class for entities that implement IEntityWithRelationships.
+    /// Using this class causes creation of the RelationshipManager to be defered to the entity object.
+    /// </summary>
+    /// <typeparam name="TEntity">The type of entity wrapped</typeparam>
+    internal sealed class EntityWrapperWithRelationships<TEntity> : EntityWrapper<TEntity>
+        where TEntity : IEntityWithRelationships
+    {
+        /// <summary>
+        /// Constructs a wrapper as part of the materialization process.  This constructor is only used
+        /// during materialization where it is known that the entity being wrapped is newly constructed.
+        /// This means that some checks are not performed that might be needed when thw wrapper is
+        /// created at other times, and information such as the identity type is passed in because
+        /// it is readily available in the materializer.
+        /// </summary>
+        /// <param name="entity">The entity to wrap</param>
+        /// <param name="key">The entity's key</param>
+        /// <param name="entitySet">The entity set, or null if none is known</param>
+        /// <param name="context">The context to which the entity should be attached</param>
+        /// <param name="mergeOption">NoTracking for non-tracked entities, AppendOnly otherwise</param>
+        /// <param name="identityType">The type of the entity ignoring any possible proxy type</param>
+        /// <param name="propertyStrategy">A delegate to create the property accesor strategy object</param>
+        /// <param name="changeTrackingStrategy">A delegate to create the change tracking strategy object</param>
+        /// <param name="keyStrategy">A delegate to create the entity key strategy object</param>
+        internal EntityWrapperWithRelationships(TEntity entity, EntityKey key, EntitySet entitySet, ObjectContext context, MergeOption mergeOption, Type identityType,
+                                                Func<object, IPropertyAccessorStrategy> propertyStrategy, Func<object, IChangeTrackingStrategy> changeTrackingStrategy, Func<object, IEntityKeyStrategy> keyStrategy)
+            : base(entity, entity.RelationshipManager, key, entitySet, context, mergeOption, identityType,
+                   propertyStrategy, changeTrackingStrategy, keyStrategy)
+        {
+        }
+
+        /// <summary>
+        /// Constructs a wrapper for the given entity.
+        /// Note: use EntityWrapperFactory instead of calling this constructor directly.
+        /// </summary>
+        /// <param name="entity">The entity to wrap</param>
+        /// <param name="propertyStrategy">A delegate to create the property accesor strategy object</param>
+        /// <param name="changeTrackingStrategy">A delegate to create the change tracking strategy object</param>
+        /// <param name="keyStrategy">A delegate to create the entity key strategy object</param>
+        internal EntityWrapperWithRelationships(TEntity entity, Func<object, IPropertyAccessorStrategy> propertyStrategy, Func<object, IChangeTrackingStrategy> changeTrackingStrategy, Func<object, IEntityKeyStrategy> keyStrategy)
+            : base(entity, entity.RelationshipManager, propertyStrategy, changeTrackingStrategy, keyStrategy)
+        {
+        }
+
+        public override bool OwnsRelationshipManager
+        {
+            get { return true; }
+        }
+
+        public override void TakeSnapshotOfRelationships(EntityEntry entry)
+        {
+        }
+
+        // See IEntityWrapper documentation
+        public override bool RequiresRelationshipChangeTracking
+        {
+            get { return false; }
+        }
+    }
+
+    /// <summary>
+    /// Implementation of the IEntityWrapper interface that is used for non-null entities that do not implement
+    /// all of our standard interfaces: IEntityWithKey, IEntityWithRelationships, and IEntityWithChangeTracker, and
+    /// are not proxies.
+    /// Different strategies for dealing with these entities are defined by strategy objects that are set into the
+    /// wrapper at constructionn time.
+    /// </summary>
+    internal abstract class EntityWrapper<TEntity> : BaseEntityWrapper<TEntity>
+    {
+        private readonly TEntity _entity;
+        private IPropertyAccessorStrategy _propertyStrategy;
+        private IChangeTrackingStrategy _changeTrackingStrategy;
+        private IEntityKeyStrategy _keyStrategy;
+
+        /// <summary>
+        /// Constructs a wrapper for the given entity.
+        /// Note: use EntityWrapperFactory instead of calling this constructor directly.
+        /// </summary>
+        /// <param name="entity">The entity to wrap</param>
+        /// <param name="relationshipManager">The RelationshipManager associated with the entity</param>
+        /// <param name="propertyStrategy">A delegate to create the property accesor strategy object</param>
+        /// <param name="changeTrackingStrategy">A delegate to create the change tracking strategy object</param>
+        /// <param name="keyStrategy">A delegate to create the entity key strategy object</param>
+        protected EntityWrapper(TEntity entity, RelationshipManager relationshipManager,
+                               Func<object, IPropertyAccessorStrategy> propertyStrategy, Func<object, IChangeTrackingStrategy> changeTrackingStrategy, Func<object, IEntityKeyStrategy> keyStrategy)
+            : base(entity, relationshipManager)
+        {
+            if (relationshipManager == null)
+            {
+                throw EntityUtil.UnexpectedNullRelationshipManager();
+            }
+            _entity = entity;
+            _propertyStrategy = propertyStrategy(entity);
+            _changeTrackingStrategy = changeTrackingStrategy(entity);
+            _keyStrategy = keyStrategy(entity);
+            Debug.Assert(_changeTrackingStrategy != null, "Change tracking strategy cannot be null.");
+            Debug.Assert(_keyStrategy != null, "Key strategy cannot be null.");
+        }
+
+        /// <summary>
+        /// Constructs a wrapper as part of the materialization process.  This constructor is only used
+        /// during materialization where it is known that the entity being wrapped is newly constructed.
+        /// This means that some checks are not performed that might be needed when thw wrapper is
+        /// created at other times, and information such as the identity type is passed in because
+        /// it is readily available in the materializer.
+        /// </summary>
+        /// <param name="entity">The entity to wrap</param>
+        /// <param name="relationshipManager">The RelationshipManager associated with the entity</param>
+        /// <param name="key">The entity's key</param>
+        /// <param name="entitySet">The entity set, or null if none is known</param>
+        /// <param name="context">The context to which the entity should be attached</param>
+        /// <param name="mergeOption">NoTracking for non-tracked entities, AppendOnly otherwise</param>
+        /// <param name="identityType">The type of the entity ignoring any possible proxy type</param>
+        /// <param name="propertyStrategy">A delegate to create the property accesor strategy object</param>
+        /// <param name="changeTrackingStrategy">A delegate to create the change tracking strategy object</param>
+        /// <param name="keyStrategy">A delegate to create the entity key strategy object</param>
+        protected EntityWrapper(TEntity entity, RelationshipManager relationshipManager, EntityKey key, EntitySet set, ObjectContext context, MergeOption mergeOption, Type identityType,
+                               Func<object, IPropertyAccessorStrategy> propertyStrategy, Func<object, IChangeTrackingStrategy> changeTrackingStrategy, Func<object, IEntityKeyStrategy> keyStrategy)
+            : base(entity, relationshipManager, set, context, mergeOption, identityType)
+        {
+            if (relationshipManager == null)
+            {
+                throw EntityUtil.UnexpectedNullRelationshipManager();
+            }
+            _entity = entity;
+            _propertyStrategy = propertyStrategy(entity);
+            _changeTrackingStrategy = changeTrackingStrategy(entity);
+            _keyStrategy = keyStrategy(entity);
+            Debug.Assert(_changeTrackingStrategy != null, "Change tracking strategy cannot be null.");
+            Debug.Assert(_keyStrategy != null, "Key strategy cannot be null.");
+            _keyStrategy.SetEntityKey(key);
+        }
+
+        // See IEntityWrapper documentation
+        public override void SetChangeTracker(IEntityChangeTracker changeTracker)
+        {
+            _changeTrackingStrategy.SetChangeTracker(changeTracker);
+        }
+
+        // See IEntityWrapper documentation
+        public override void TakeSnapshot(EntityEntry entry)
+        {
+            _changeTrackingStrategy.TakeSnapshot(entry);
+        }
+
+        // See IEntityWrapper documentation
+        public override EntityKey EntityKey
+        {
+            // If no strategy is set, then the key maintained by the wrapper is used,
+            // otherwise the request is passed to the strategy.
+            get
+            {
+                return _keyStrategy.GetEntityKey();
+            }
+            set
+            {
+                _keyStrategy.SetEntityKey(value);
+            }
+        }
+
+        public override EntityKey GetEntityKeyFromEntity()
+        {
+            return _keyStrategy.GetEntityKeyFromEntity();
+        }
+
+        public override void CollectionAdd(RelatedEnd relatedEnd, object value)
+        {
+            if (_propertyStrategy != null)
+            {
+                _propertyStrategy.CollectionAdd(relatedEnd, value);
+            }
+        }
+
+        public override bool CollectionRemove(RelatedEnd relatedEnd, object value)
+        {
+            return _propertyStrategy != null ? _propertyStrategy.CollectionRemove(relatedEnd, value) : false;
+        }
+
+        // See IEntityWrapper documentation
+        public override void EnsureCollectionNotNull(RelatedEnd relatedEnd)
+        {
+            if (_propertyStrategy != null)
+            {
+                object collection = _propertyStrategy.GetNavigationPropertyValue(relatedEnd);
+                if (collection == null)
+                {
+                    collection = _propertyStrategy.CollectionCreate(relatedEnd);
+                    _propertyStrategy.SetNavigationPropertyValue(relatedEnd, collection);
+                }
+            }
+        }
+
+        // See IEntityWrapper documentation
+        public override object GetNavigationPropertyValue(RelatedEnd relatedEnd)
+        {
+            return _propertyStrategy != null ? _propertyStrategy.GetNavigationPropertyValue(relatedEnd) : null;
+        }
+
+        // See IEntityWrapper documentation
+        public override void SetNavigationPropertyValue(RelatedEnd relatedEnd, object value)
+        {
+            if (_propertyStrategy != null)
+            {
+                _propertyStrategy.SetNavigationPropertyValue(relatedEnd, value);
+            }
+        }
+
+        // See IEntityWrapper documentation
+        public override void RemoveNavigationPropertyValue(RelatedEnd relatedEnd, object value)
+        {
+            if (_propertyStrategy != null)
+            {
+                object currentValue = _propertyStrategy.GetNavigationPropertyValue(relatedEnd);
+
+                if (Object.ReferenceEquals(currentValue, value))
+                {
+                    _propertyStrategy.SetNavigationPropertyValue(relatedEnd, null);
+                }
+            }
+        }
+
+        // See IEntityWrapper documentation
+        public override object Entity
+        {
+            get { return _entity; }
+        }
+
+        // See IEntityWrapper<TEntity> documentation
+        public override TEntity TypedEntity
+        {
+            get { return _entity; }
+        }
+
+        // See IEntityWrapper documentation
+        public override void SetCurrentValue(EntityEntry entry, StateManagerMemberMetadata member, int ordinal, object target, object value)
+        {
+            _changeTrackingStrategy.SetCurrentValue(entry, member, ordinal, target, value);
+        }
+
+        // See IEntityWrapper documentation
+        public override void UpdateCurrentValueRecord(object value, EntityEntry entry)
+        {
+            _changeTrackingStrategy.UpdateCurrentValueRecord(value, entry);
+        }
+    }
+}

mcs/class/referencesource/System.Data.Entity/System/Data/Objects/Internal/EntityWrapperFactory.cs

@@ -0,0 +1,363 @@
+//---------------------------------------------------------------------
+// <copyright file="EntityWrapperFactory.cs" company="Microsoft">
+//      Copyright (c) Microsoft Corporation.  All rights reserved.
+// </copyright>
+//
+// @owner       [....]
+// @backupOwner [....]
+//---------------------------------------------------------------------
+using System.Data.Objects.DataClasses;
+using System.Data.Metadata.Edm;
+using System.Diagnostics;
+using System.ComponentModel;
+using System.Collections.Generic;
+using System.Reflection;
+using System.Linq.Expressions;
+using System.Security.Permissions;
+using System.Threading;
+using System.Data.Common.Utils;
+using System.Runtime.CompilerServices;
+
+namespace System.Data.Objects.Internal
+{
+    /// <summary>
+    /// Factory class for creating IEntityWrapper instances.
+    /// </summary>
+    internal static class EntityWrapperFactory
+    {
+        // A cache of functions used to create IEntityWrapper instances for a given type
+        private static readonly Memoizer<Type, Func<object, IEntityWrapper>> _delegateCache = new Memoizer<Type, Func<object, IEntityWrapper>>(CreateWrapperDelegate, null);
+
+        /// <summary>
+        /// The single instance of the NullEntityWrapper.
+        /// </summary>
+        internal static IEntityWrapper NullWrapper
+        {
+            get { return NullEntityWrapper.NullWrapper; }
+        }
+
+        /// <summary>
+        /// Called to create a new wrapper outside of the normal materialization process.
+        /// This method is typically used when a new entity is created outside the context and then is
+        /// added or attached.  The materializer bypasses this method and calls wrapper constructors
+        /// directory for performance reasons.
+        /// This method does not check whether or not the wrapper already exists in the context.
+        /// </summary>
+        /// <param name="entity">The entity for which a wrapper will be created</param>
+        /// <param name="key">The key associated with that entity, or null</param>
+        /// <returns>The new wrapper instance</returns>
+        internal static IEntityWrapper CreateNewWrapper(object entity, EntityKey key)
+        {
+            Debug.Assert(!(entity is IEntityWrapper), "Object is an IEntityWrapper instance instead of the raw entity.");
+            if (entity == null)
+            {
+                return NullEntityWrapper.NullWrapper;
+            }
+            // We used a cache of functions based on the actual type of entity that we need to wrap.
+            // Creatung these functions is slow, but once they are created they are relatively fast.
+            IEntityWrapper wrappedEntity = _delegateCache.Evaluate(entity.GetType())(entity);
+            wrappedEntity.RelationshipManager.SetWrappedOwner(wrappedEntity, entity);
+            // We cast to object here to avoid calling the overridden != operator on EntityKey.
+            // This creates a very small perf gain, which is none-the-less significant for lean no-tracking cases.
+            if ((object)key != null && (object)wrappedEntity.EntityKey == null)
+            {
+                wrappedEntity.EntityKey = key;
+            }
+
+            // If the entity is a proxy, set the wrapper to match
+            EntityProxyTypeInfo proxyTypeInfo;
+            if (EntityProxyFactory.TryGetProxyType(entity.GetType(), out proxyTypeInfo))
+            {
+                proxyTypeInfo.SetEntityWrapper(wrappedEntity);
+            }
+
+            return wrappedEntity;
+        }
+
+        // Creates a delegate that can then be used to create wrappers for a given type.
+        // This is slow which is why we only create the delegate once and then cache it.
+        [MethodImpl(MethodImplOptions.NoInlining | MethodImplOptions.NoOptimization)]
+        private static Func<object, IEntityWrapper> CreateWrapperDelegate(Type entityType)
+        {
+            // For entities that implement all our interfaces we create a special lightweight wrapper that is both
+            // smaller and faster than the strategy-based wrapper.
+            // Otherwise, the wrapper is provided with different delegates depending on which interfaces are implemented.
+            bool isIEntityWithRelationships = typeof(IEntityWithRelationships).IsAssignableFrom(entityType);
+            bool isIEntityWithChangeTracker = typeof(IEntityWithChangeTracker).IsAssignableFrom(entityType);
+            bool isIEntityWithKey = typeof(IEntityWithKey).IsAssignableFrom(entityType);
+            bool isProxy = EntityProxyFactory.IsProxyType(entityType);
+            MethodInfo createDelegate;
+            if (isIEntityWithRelationships && isIEntityWithChangeTracker && isIEntityWithKey && !isProxy)
+            {
+                createDelegate = typeof(EntityWrapperFactory).GetMethod("CreateWrapperDelegateTypedLightweight", BindingFlags.NonPublic | BindingFlags.Static);
+            }
+            else if (isIEntityWithRelationships)
+            {
+                // This type of strategy wrapper is used when the entity implements IEntityWithRelationships
+                // In this case it is important that the entity itself is used to create the RelationshipManager
+                createDelegate = typeof(EntityWrapperFactory).GetMethod("CreateWrapperDelegateTypedWithRelationships", BindingFlags.NonPublic | BindingFlags.Static);
+            }
+            else
+            {
+                createDelegate = typeof(EntityWrapperFactory).GetMethod("CreateWrapperDelegateTypedWithoutRelationships", BindingFlags.NonPublic | BindingFlags.Static);
+            }
+            createDelegate = createDelegate.MakeGenericMethod(entityType);
+            return (Func<object, IEntityWrapper>)createDelegate.Invoke(null, new object[0]);
+        }
+
+        // Returns a delegate that creates the fast LightweightEntityWrapper
+        private static Func<object, IEntityWrapper> CreateWrapperDelegateTypedLightweight<TEntity>()
+             where TEntity : IEntityWithRelationships, IEntityWithKey, IEntityWithChangeTracker
+        {
+            return (entity) => new LightweightEntityWrapper<TEntity>((TEntity)entity);
+        }
+
+        // Returns a delegate that creates a strategy-based wrapper for entities that implement IEntityWithRelationships
+        private static Func<object, IEntityWrapper> CreateWrapperDelegateTypedWithRelationships<TEntity>()
+            where TEntity : IEntityWithRelationships
+        {
+            Func<object, IPropertyAccessorStrategy> propertyAccessorStrategy;
+            Func<object, IEntityKeyStrategy> keyStrategy;
+            Func<object, IChangeTrackingStrategy> changeTrackingStrategy;
+            CreateStrategies<TEntity>(out propertyAccessorStrategy, out changeTrackingStrategy, out keyStrategy);
+            
+            return (entity) => new EntityWrapperWithRelationships<TEntity>((TEntity)entity, propertyAccessorStrategy, changeTrackingStrategy, keyStrategy);
+        }
+
+        // Returns a delegate that creates a strategy-based wrapper for entities that do not implement IEntityWithRelationships
+        private static Func<object, IEntityWrapper> CreateWrapperDelegateTypedWithoutRelationships<TEntity>()
+        {
+            Func<object, IPropertyAccessorStrategy> propertyAccessorStrategy;
+            Func<object, IEntityKeyStrategy> keyStrategy;
+            Func<object, IChangeTrackingStrategy> changeTrackingStrategy;
+            CreateStrategies<TEntity>(out propertyAccessorStrategy, out changeTrackingStrategy, out keyStrategy);
+
+            return (entity) => new EntityWrapperWithoutRelationships<TEntity>((TEntity)entity, propertyAccessorStrategy, changeTrackingStrategy, keyStrategy);
+        }
+
+        // Creates delegates that create strategy objects appropriate for the type of entity.
+        private static void CreateStrategies<TEntity>(out Func<object, IPropertyAccessorStrategy> createPropertyAccessorStrategy,
+                                                      out Func<object, IChangeTrackingStrategy> createChangeTrackingStrategy,
+                                                      out Func<object, IEntityKeyStrategy> createKeyStrategy)
+        {
+            Type entityType = typeof(TEntity);
+            bool isIEntityWithRelationships = typeof(IEntityWithRelationships).IsAssignableFrom(entityType);
+            bool isIEntityWithChangeTracker = typeof(IEntityWithChangeTracker).IsAssignableFrom(entityType);
+            bool isIEntityWithKey = typeof(IEntityWithKey).IsAssignableFrom(entityType);
+            bool isProxy = EntityProxyFactory.IsProxyType(entityType);
+
+            if (!isIEntityWithRelationships || isProxy)
+            {
+                createPropertyAccessorStrategy = GetPocoPropertyAccessorStrategyFunc();
+            }
+            else
+            {
+                createPropertyAccessorStrategy = GetNullPropertyAccessorStrategyFunc();
+            }
+
+            if (isIEntityWithChangeTracker)
+            {
+                createChangeTrackingStrategy = GetEntityWithChangeTrackerStrategyFunc();
+            }
+            else
+            {
+                createChangeTrackingStrategy = GetSnapshotChangeTrackingStrategyFunc();
+            }
+
+            if (isIEntityWithKey)
+            {
+                createKeyStrategy = GetEntityWithKeyStrategyStrategyFunc();
+            }
+            else
+            {
+                createKeyStrategy = GetPocoEntityKeyStrategyFunc();
+            }
+        }
+
+        /// <summary>
+        /// Convenience function that gets the ObjectStateManager from the context and calls
+        /// WrapEntityUsingStateManager.
+        /// </summary>
+        /// <param name="entity">the entity to wrap</param>
+        /// <param name="context">the context in which the entity may exist, or null</param>
+        /// <returns>a new or existing wrapper</returns>
+        internal static IEntityWrapper WrapEntityUsingContext(object entity, ObjectContext context)
+        {
+            EntityEntry existingEntry;
+            return WrapEntityUsingStateManagerGettingEntry(entity, context == null ? null : context.ObjectStateManager, out existingEntry);
+        }
+
+        /// <summary>
+        /// Convenience function that gets the ObjectStateManager from the context and calls
+        /// WrapEntityUsingStateManager.
+        /// </summary>
+        /// <param name="entity">The entity to wrap</param>
+        /// <param name="context">The context in which the entity may exist, or null</param>
+        /// <param name="existingEntry">Set to the existing state entry if one is found, else null</param>
+        /// <returns>a new or existing wrapper</returns>
+        internal static IEntityWrapper WrapEntityUsingContextGettingEntry(object entity, ObjectContext context, out EntityEntry existingEntry)
+        {
+            return WrapEntityUsingStateManagerGettingEntry(entity, context == null ? null : context.ObjectStateManager, out existingEntry);
+        }
+
+        /// <summary>
+        /// Wraps an entity and returns a new wrapper, or returns an existing wrapper if one
+        /// already exists in the ObjectStateManager or in a RelationshipManager associated with
+        /// the entity.
+        /// </summary>
+        /// <param name="entity">the entity to wrap</param>
+        /// <param name="context">the state manager  in which the entity may exist, or null</param>
+        /// <returns>a new or existing wrapper</returns>
+        internal static IEntityWrapper WrapEntityUsingStateManager(object entity, ObjectStateManager stateManager)
+        {
+            EntityEntry existingEntry;
+            return WrapEntityUsingStateManagerGettingEntry(entity, stateManager, out existingEntry);
+        }
+
+        /// <summary>
+        /// Wraps an entity and returns a new wrapper, or returns an existing wrapper if one
+        /// already exists in the ObjectStateManager or in a RelationshipManager associated with
+        /// the entity.
+        /// </summary>
+        /// <param name="entity">The entity to wrap</param>
+        /// <param name="context">The state manager  in which the entity may exist, or null</param>
+        /// <param name="existingEntry">The existing state entry for the given entity if one exists, otherwise null</param>
+        /// <returns>A new or existing wrapper</returns>
+        internal static IEntityWrapper WrapEntityUsingStateManagerGettingEntry(object entity, ObjectStateManager stateManager, out EntityEntry existingEntry)
+        {
+            Debug.Assert(!(entity is IEntityWrapper), "Object is an IEntityWrapper instance instead of the raw entity.");
+            IEntityWrapper wrapper = null;
+            existingEntry = null;
+
+            if (entity == null)
+            {
+                return NullEntityWrapper.NullWrapper;
+            }
+            // First attempt to find an existing wrapper in the ObjectStateMager.
+            if (stateManager != null)
+            {
+                existingEntry = stateManager.FindEntityEntry(entity);
+                if (existingEntry != null)
+                {
+                    return existingEntry.WrappedEntity;
+                }
+                if (stateManager.TransactionManager.TrackProcessedEntities)
+                {
+                    if (stateManager.TransactionManager.WrappedEntities.TryGetValue(entity, out wrapper))
+                    {
+                        return wrapper;
+                    }
+                }
+            }
+            // If no entity was found in the OSM, then check if one exists on an associated
+            // RelationshipManager.  This only works where the entity implements IEntityWithRelationshops.
+            IEntityWithRelationships entityWithRelationships = entity as IEntityWithRelationships;
+            if (entityWithRelationships != null)
+            {
+                RelationshipManager relManager = entityWithRelationships.RelationshipManager;
+                if (relManager == null)
+                {
+                    throw EntityUtil.UnexpectedNullRelationshipManager();
+                }
+                IEntityWrapper wrappedEntity = relManager.WrappedOwner;
+                if (!Object.ReferenceEquals(wrappedEntity.Entity, entity))
+                {
+                    // This means that the owner of the RelationshipManager must have been set
+                    // incorrectly in the call to RelationshipManager.Create().
+                    throw EntityUtil.InvalidRelationshipManagerOwner();
+                }
+                return wrappedEntity;
+            }
+            else
+            {
+                // Finally look to see if the instance is a proxy and get the wrapper from the proxy
+                EntityProxyFactory.TryGetProxyWrapper(entity, out wrapper);
+            }
+
+            // If we could not find an existing wrapper, then go create a new one
+            if (wrapper == null)
+            {
+                IEntityWithKey withKey = entity as IEntityWithKey;
+                wrapper = CreateNewWrapper(entity, withKey == null ? null : withKey.EntityKey);
+            }
+            if (stateManager != null && stateManager.TransactionManager.TrackProcessedEntities)
+            {
+                stateManager.TransactionManager.WrappedEntities.Add(entity, wrapper);
+            }
+            return wrapper;
+        }
+
+        /// <summary>
+        /// When an entity enters Object Services that was retreived with NoTracking, it may not have certain fields set that are in many cases
+        /// assumed to be present. This method updates the wrapper with a key and a context.
+        /// </summary>
+        /// <param name="wrapper">The wrapped entity</param>
+        /// <param name="context">The context that will be using this wrapper</param>
+        /// <param name="entitySet">The entity set this wrapped entity belongs to</param>
+        internal static void UpdateNoTrackingWrapper(IEntityWrapper wrapper, ObjectContext context, EntitySet entitySet)
+        {
+            if (wrapper.EntityKey == null)
+            {
+                wrapper.EntityKey = context.ObjectStateManager.CreateEntityKey(entitySet, wrapper.Entity);
+            }
+            if (wrapper.Context == null)
+            {
+                wrapper.AttachContext(context, entitySet, MergeOption.NoTracking);
+            }
+        }
+
+        /// <summary>
+        /// Returns a func that will create a PocoPropertyAccessorStrategy object for a given entity.
+        /// </summary>
+        /// <returns>The func to be used to create the strategy object.</returns>
+        internal static Func<object, IPropertyAccessorStrategy> GetPocoPropertyAccessorStrategyFunc()
+        {
+            return (object entity) => new PocoPropertyAccessorStrategy(entity);
+        }
+
+        /// <summary>
+        /// Returns a func that will create a null IPropertyAccessorStrategy strategy object for a given entity.
+        /// </summary>
+        /// <returns>The func to be used to create the strategy object.</returns>
+        internal static Func<object, IPropertyAccessorStrategy> GetNullPropertyAccessorStrategyFunc()
+        {
+            return (object entity) => null;
+        }
+
+        /// <summary>
+        /// Returns a func that will create a EntityWithChangeTrackerStrategy object for a given entity.
+        /// </summary>
+        /// <returns>The func to be used to create the strategy object.</returns>
+        internal static Func<object, IChangeTrackingStrategy> GetEntityWithChangeTrackerStrategyFunc()
+        {
+            return (object entity) => new EntityWithChangeTrackerStrategy((IEntityWithChangeTracker)entity);
+        }
+
+        /// <summary>
+        /// Returns a func that will create a SnapshotChangeTrackingStrategy object for a given entity.
+        /// </summary>
+        /// <returns>The func to be used to create the strategy object.</returns>
+        internal static Func<object, IChangeTrackingStrategy> GetSnapshotChangeTrackingStrategyFunc()
+        {
+            return (object entity) => SnapshotChangeTrackingStrategy.Instance;
+        }
+
+        /// <summary>
+        /// Returns a func that will create a EntityWithKeyStrategy object for a given entity.
+        /// </summary>
+        /// <returns>The func to be used to create the strategy object.</returns>
+        internal static Func<object, IEntityKeyStrategy> GetEntityWithKeyStrategyStrategyFunc()
+        {
+            return (object entity) => new EntityWithKeyStrategy((IEntityWithKey)entity);
+        }
+
+        /// <summary>
+        /// Returns a func that will create a GetPocoEntityKeyStrategyFunc object for a given entity.
+        /// </summary>
+        /// <returns>The func to be used to create the strategy object.</returns>
+        internal static Func<object, IEntityKeyStrategy> GetPocoEntityKeyStrategyFunc()
+        {
+            return (object entity) => new PocoEntityKeyStrategy();
+        }
+    }
+}

mcs/class/referencesource/System.Data.Entity/System/Data/Objects/Internal/ForeignKeyFactory.cs

@@ -0,0 +1,134 @@
+//---------------------------------------------------------------------
+// <copyright file="ForeignKeyFactory.cs" company="Microsoft">
+//     Copyright (c) Microsoft Corporation.  All rights reserved.
+// </copyright>
+//---------------------------------------------------------------------
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Data;
+using System.Data.Metadata.Edm;
+using System.Diagnostics;
+using System.Data.Objects.DataClasses;
+
+namespace System.Data.Objects.Internal
+{
+    internal class ForeignKeyFactory
+    {
+        private const string s_NullPart = "EntityHasNullForeignKey";
+        private const string s_NullForeignKey = "EntityHasNullForeignKey.EntityHasNullForeignKey";
+
+        /// <summary>
+        /// Returns true if the supplied key represents a Conceptual Null
+        /// </summary>
+        /// <param name="key">The key to be checked</param>
+        public static bool IsConceptualNullKey(EntityKey key)
+        {
+            if (key == null)
+            {
+                return false;
+            }
+
+            return string.Equals(key.EntityContainerName, s_NullPart) &&
+                   string.Equals(key.EntitySetName, s_NullPart);
+        }
+
+        /// <summary>
+        /// Checks if the Real Key represents different FK values 
+        /// than those present when the Conceptual Null was created
+        /// </summary>
+        /// <param name="conceptualNullKey">The key representing the Conceptual Null</param>
+        /// <param name="realKey">The key to be checked</param>
+        /// <returns>True if the values are different, false otherwise</returns>
+        public static bool IsConceptualNullKeyChanged(EntityKey conceptualNullKey, EntityKey realKey)
+        {
+            Debug.Assert(IsConceptualNullKey(conceptualNullKey), "The key supplied is not a null key");
+
+            if (realKey == null)
+            {
+                return true;
+            }
+
+            return !EntityKey.InternalEquals(conceptualNullKey, realKey, compareEntitySets: false); 
+        }
+
+        /// <summary>
+        /// Creates an EntityKey that represents a Conceptual Null
+        /// </summary>
+        /// <param name="originalKey">An EntityKey representing the existing FK values that could not be nulled</param>
+        /// <returns>EntityKey marked as a conceptual null with the FK values from the original key</returns>
+        public static EntityKey CreateConceptualNullKey(EntityKey originalKey)
+        {
+            Debug.Assert(originalKey != null, "Original key can not be null");
+
+            //Conceptual nulls have special entity set name and a copy of the previous values
+            EntityKey nullKey = new EntityKey(s_NullForeignKey, originalKey.EntityKeyValues);
+            return nullKey;
+        }
+
+        /// <summary>
+        /// Creates an EntityKey for a principal entity based on the foreign key values contained
+        /// in this entity.  This implies that this entity is at the dependent end of the relationship.
+        /// </summary>
+        /// <param name="dependentEntry">The EntityEntry for the dependent that contains the FK</param>
+        /// <param name="relatedEnd">Identifies the principal end for which a key is required</param>
+        /// <returns>The key, or null if any value in the key is null</returns>
+        public static EntityKey CreateKeyFromForeignKeyValues(EntityEntry dependentEntry, RelatedEnd relatedEnd)
+        {
+            // Note: there is only ever one constraint per association type
+            ReferentialConstraint constraint = ((AssociationType)relatedEnd.RelationMetadata).ReferentialConstraints.First();
+            Debug.Assert(constraint.FromRole.Identity == relatedEnd.TargetRoleName, "Unexpected constraint role");
+            return CreateKeyFromForeignKeyValues(dependentEntry, constraint, relatedEnd.GetTargetEntitySetFromRelationshipSet(), useOriginalValues: false);
+        }
+
+        /// <summary>
+        /// Creates an EntityKey for a principal entity based on the foreign key values contained
+        /// in this entity.  This implies that this entity is at the dependent end of the relationship.
+        /// </summary>
+        /// <param name="dependentEntry">The EntityEntry for the dependent that contains the FK</param>
+        /// <param name="constraint">The constraint that describes this FK relationship</param>
+        /// <param name="principalEntitySet">The entity set at the principal end of the the relationship</param>
+        /// <param name="useOriginalValues">If true then the key will be constructed from the original FK values</param>
+        /// <returns>The key, or null if any value in the key is null</returns>
+        public static EntityKey CreateKeyFromForeignKeyValues(EntityEntry dependentEntry, ReferentialConstraint constraint, EntitySet principalEntitySet, bool useOriginalValues)
+        {
+            // Build the key values.  If any part of the key is null, then the entire key
+            // is considered null.
+            var dependentProps = constraint.ToProperties;
+            int numValues = dependentProps.Count;
+            if (numValues == 1)
+            {
+                object keyValue = useOriginalValues ?
+                    dependentEntry.GetOriginalEntityValue(dependentProps.First().Name) :
+                    dependentEntry.GetCurrentEntityValue(dependentProps.First().Name);
+                return keyValue == DBNull.Value ? null : new EntityKey(principalEntitySet, keyValue);
+            }
+
+            // Note that the properties in the principal entity set may be in a different order than
+            // they appear in the constraint.  Therefore, we create name value mappings to ensure that
+            // the correct values are associated with the correct properties.
+            // Unfortunately, there is not way to call the public EntityKey constructor that takes pairs
+            // because the internal "object" constructor hides it.  Even this doesn't work:
+            // new EntityKey(principalEntitySet, (IEnumerable<KeyValuePair<string, object>>)keyValues)
+            string[] keyNames = principalEntitySet.ElementType.KeyMemberNames;
+            Debug.Assert(keyNames.Length == numValues, "Number of entity set key names does not match constraint names");
+            object[] values = new object[numValues];
+            var principalProps = constraint.FromProperties;
+            for (int i = 0; i < numValues; i++)
+            {
+                object value = useOriginalValues ?
+                    dependentEntry.GetOriginalEntityValue(dependentProps[i].Name) :
+                    dependentEntry.GetCurrentEntityValue(dependentProps[i].Name);
+                if (value == DBNull.Value)
+                {
+                    return null;
+                }
+                int keyIndex = Array.IndexOf(keyNames, principalProps[i].Name);
+                Debug.Assert(keyIndex >= 0 && keyIndex < numValues, "Could not find constraint prop name in entity set key names");
+                values[keyIndex] = value;
+            }
+            return new EntityKey(principalEntitySet, values);
+        }
+    }
+}

mcs/class/referencesource/System.Data.Entity/System/Data/Objects/Internal/IChangeTrackingStrategy.cs

@@ -0,0 +1,52 @@
+//------------------------------------------------------------------------------
+// <copyright file="IChangeTrackingStrategy.cs" company="Microsoft">
+//     Copyright (c) Microsoft Corporation.  All rights reserved.
+// </copyright>
+//------------------------------------------------------------------------------
+
+using System;
+using System.Collections.Generic;
+using System.Text;
+using System.Data.Objects.DataClasses;
+
+namespace System.Data.Objects.Internal
+{
+    /// <summary>
+    /// A strategy interface that defines methods used for different types of change tracking.
+    /// Implementors of this interface are used by the EntityWrapper class.
+    /// </summary>
+    internal interface IChangeTrackingStrategy
+    {
+        /// <summary>
+        /// Sets a change tracker onto an entity, or does nothing if the entity does not support change trackers.
+        /// </summary>
+        /// <param name="changeTracker">The change tracker to set</param>
+        void SetChangeTracker(IEntityChangeTracker changeTracker);
+
+        /// <summary>
+        /// Takes a snapshot of the entity contained in the given state entry, or does nothing if
+        /// snapshots are not required for the entity.
+        /// </summary>
+        /// <param name="entry">The state entry representing the entity to snapshot</param>
+        void TakeSnapshot(EntityEntry entry);
+
+        /// <summary>
+        /// Sets the given value onto the entity with the registered change either handled by the
+        /// entity itself or by using the given EntityEntry as the change tracker.
+        /// </summary>
+        /// <param name="entry">The state entry of the entity to for which a value should be set</param>
+        /// <param name="member">State member information indicating the member to set</param>
+        /// <param name="ordinal">The ordinal of the member to set</param>
+        /// <param name="target">The object onto which the value should be set; may be the entity, or a contained complex value</param>
+        /// <param name="value">The value to set</param>
+        void SetCurrentValue(EntityEntry entry, StateManagerMemberMetadata member, int ordinal, object target, object value);
+
+        /// <summary>
+        /// Updates the current value records using Shaper.UpdateRecord but with additional change tracking logic
+        /// added as required by POCO and proxy entities.
+        /// </summary>
+        /// <param name="value">The value</param>
+        /// <param name="entry">The existing ObjectStateEntry</param>
+        void UpdateCurrentValueRecord(object value, EntityEntry entry);
+    }
+}

mcs/class/referencesource/System.Data.Entity/System/Data/Objects/Internal/IEntityKeyStrategy.cs

@@ -0,0 +1,37 @@
+//---------------------------------------------------------------------
+// <copyright file="IEntityKeyStrategy.cs" company="Microsoft">
+//     Copyright (c) Microsoft Corporation.  All rights reserved.
+// </copyright>
+//---------------------------------------------------------------------
+using System;
+using System.Collections.Generic;
+using System.Text;
+using System.Data.Objects.DataClasses;
+
+namespace System.Data.Objects.Internal
+{
+    /// <summary>
+    /// A strategy interface that defines methods used for setting and getting EntityKey values on an entity.
+    /// Implementors of this interface are used by the EntityWrapper class.
+    /// </summary>
+    internal interface IEntityKeyStrategy
+    {
+        /// <summary>
+        /// Gets the entity key.
+        /// </summary>
+        /// <returns>The key</returns>
+        EntityKey GetEntityKey();
+
+        /// <summary>
+        /// Sets the entity key
+        /// </summary>
+        /// <param name="key">The key</param>
+        void SetEntityKey(EntityKey key);
+
+        /// <summary>
+        /// Returns the entity key directly from the entity
+        /// </summary>
+        /// <returns>the key</returns>
+        EntityKey GetEntityKeyFromEntity();
+    }
+}

mcs/class/referencesource/System.Data.Entity/System/Data/Objects/Internal/IEntityWrapper.cs

@@ -0,0 +1,200 @@
+//---------------------------------------------------------------------
+// <copyright file="IEntityWrapper.cs" company="Microsoft">
+//      Copyright (c) Microsoft Corporation.  All rights reserved.
+// </copyright>
+//
+// @owner       avickers
+// @backupOwner jeffders
+//---------------------------------------------------------------------
+using System.Collections;
+using System.Data.Objects.DataClasses;
+using System.Runtime.CompilerServices;
+using System.Data.Metadata.Edm;
+
+namespace System.Data.Objects.Internal
+{
+    /// <summary>
+    /// Internally, entities are wrapped in some implementation of this
+    /// interface.  This allows the RelationshipManager and other classes
+    /// to treat POCO entities and traditional entities in the same way
+    /// where ever possible.
+    /// </summary>
+    internal interface IEntityWrapper
+    {
+        /// <summary>
+        /// The Relationship Manager that is associated with the wrapped entity.
+        /// </summary>
+        RelationshipManager RelationshipManager { get; }
+
+        /// <summary>
+        /// Information about whether or not the entity instance actually owns and uses its RelationshipManager
+        /// This is used to determine how to do relationship fixup in some cases
+        /// </summary>
+        bool OwnsRelationshipManager { get; }
+
+        /// <summary>
+        /// The actual entity that is wrapped by this wrapper object.
+        /// </summary>
+        object Entity { get; }
+
+        /// <summary>
+        /// If this IEntityWrapper is tracked, accesses the ObjectStateEntry that is used in the state manager
+        /// </summary>
+        EntityEntry ObjectStateEntry { get; set; }
+
+        /// <summary>
+        /// Ensures that the collection with the given name is not null by setting a new empty
+        /// collection onto the property if necessary.
+        /// </summary>
+        /// <param name="collectionName">The name of the collection to operate on</param>
+        void EnsureCollectionNotNull(RelatedEnd relatedEnd);
+
+        /// <summary>
+        /// The key associated with this entity, which may be null if no key is known.
+        /// </summary>
+        EntityKey EntityKey { get; set; }
+
+        /// <summary>
+        /// Retrieves the EntityKey from the entity if it implements IEntityWithKey
+        /// </summary>
+        /// <returns>The EntityKey on the entity</returns>
+        EntityKey GetEntityKeyFromEntity();
+
+        /// <summary>
+        /// The context with which the wrapped entity is associated, or null if the entity
+        /// is detached.
+        /// </summary>
+        ObjectContext Context { get; set; }
+
+        /// <summary>
+        /// The merge option assoicated with the wrapped entity.
+        /// </summary>
+        MergeOption MergeOption { get; }
+
+        /// <summary>
+        /// Attaches the wrapped entity to the given context.
+        /// </summary>
+        /// <param name="context">the context with which to associate this entity</param>
+        /// <param name="entitySet">the entity set to which the entity belongs</param>
+        /// <param name="mergeOption">the merge option to use</param>
+        void AttachContext(ObjectContext context, EntitySet entitySet, MergeOption mergeOption);
+
+        /// <summary>
+        /// Resets the context with which the wrapped entity is associated.
+        /// </summary>
+        /// <param name="context">the context with which to associate this entity</param>
+        /// <param name="entitySet">the entity set to which the entity belongs</param>
+        /// <param name="mergeOption">the merge option to use</param>
+        void ResetContext(ObjectContext context, EntitySet entitySet, MergeOption mergeOption);
+
+        /// <summary>
+        /// Detaches the wrapped entity from its associated context.
+        /// </summary>
+        void DetachContext();
+
+        /// <summary>
+        /// Sets the entity's ObjectStateEntry as the entity's change tracker if possible.
+        /// The ObjectStateEntry may be null when a change tracker is being removed from an
+        /// entity.
+        /// </summary>
+        /// <param name="changeTracker">the object to use as a change tracker</param>
+        void SetChangeTracker(IEntityChangeTracker changeTracker);
+
+        /// <summary>
+        /// Takes a snapshot of the entity state unless the entity has an associated
+        /// change tracker or the given entry is null, in which case no action is taken.
+        /// </summary>
+        /// <param name="entry">the entity's associated state entry</param>
+        void TakeSnapshot(EntityEntry entry);
+
+        /// <summary>
+        /// Takes a snapshot of the relationships of the entity stored in the entry
+        /// </summary>
+        /// <param name="entry"></param>
+        void TakeSnapshotOfRelationships(EntityEntry entry);
+
+        /// <summary>
+        /// The Type object that should be used to identify this entity in o-space.
+        /// This is normally just the type of the entity object, but if the object
+        /// is a proxy that we have generated, then the type of the base class is returned instead.
+        /// This ensures that both proxy entities and normal entities are treated as the
+        /// same kind of entity in the metadata and places where the metadata is used.
+        /// </summary>
+        Type IdentityType { get; }
+
+        /// <summary>
+        /// Populates a value into a collection of values stored in a property of the entity.
+        /// If the collection to be populated is actually managed by and returned from
+        /// the RelationshipManager when needed, then this method is a no-op.  This is
+        /// typically the case for non-POCO entities.
+        /// </summary>
+        void CollectionAdd(RelatedEnd relatedEnd, object value);
+
+        /// <summary>
+        /// Removes a value from a collection of values stored in a property of the entity.
+        /// If the collection to be updated is actually managed by and returned from
+        /// the RelationshipManager when needed, then this method is a no-op.  This is
+        /// typically the case for non-POCO entities.
+        /// </summary>
+        bool CollectionRemove(RelatedEnd relatedEnd, object value);
+
+        /// <summary>
+        /// Returns value of the entity's property described by the navigation property.
+        /// </summary>
+        /// <param name="relatedEnd">navigation property to retrieve</param>
+        /// <returns></returns>
+        object GetNavigationPropertyValue(RelatedEnd relatedEnd);
+
+        /// <summary>
+        /// Populates a single value into a field or property of the entity.
+        /// If the element to be populated is actually managed by and returned from
+        /// the RelationshipManager when needed, then this method is a no-op.  This is
+        /// typically the case for non-POCO entities.
+        /// </summary>
+        void SetNavigationPropertyValue(RelatedEnd relatedEnd, object value);
+
+        /// <summary>
+        /// Removes a single value from a field or property of the entity.
+        /// If the field or property contains reference to a different object,
+        /// this method is a no-op.
+        /// If the element to be populated is actually managed by and returned from
+        /// the RelationshipManager when needed, then this method is a no-op.  This is
+        /// typically the case for non-POCO entities.
+        /// </summary>
+        /// <param name="value">The value to remove</param>
+        void RemoveNavigationPropertyValue(RelatedEnd relatedEnd, object value);
+
+        /// <summary>
+        /// Sets the given value onto the entity with the registered change either handled by the
+        /// entity itself or by using the given EntityEntry as the change tracker.
+        /// </summary>
+        /// <param name="entry">The state entry of the entity to for which a value should be set</param>
+        /// <param name="member">State member information indicating the member to set</param>
+        /// <param name="ordinal">The ordinal of the member to set</param>
+        /// <param name="target">The object onto which the value should be set; may be the entity, or a contained complex value</param>
+        /// <param name="value">The value to set</param>
+        void SetCurrentValue(EntityEntry entry, StateManagerMemberMetadata member, int ordinal, object target, object value);
+
+        /// <summary>
+        /// Set to true while the process of initalizing RelatedEnd objects for an IPOCO proxy is in process.
+        /// This flag prevents the context from being set onto the related ends, which in turn means that
+        /// the related ends don't need to have keys, which in turn means they don't need to be part of an EntitySet.
+        /// </summary>
+        bool InitializingProxyRelatedEnds { get; set; }
+
+        /// <summary>
+        /// Updates the current value records using Shaper.UpdateRecord but with additional change tracking logic
+        /// added as required by POCO and proxy entities.  For the simple case of no proxy and an entity with
+        /// a change tracker, this translates into a simple call to ShaperUpdateRecord.
+        /// </summary>
+        /// <param name="value">The value</param>
+        /// <param name="entry">The existing ObjectStateEntry</param>
+        void UpdateCurrentValueRecord(object value, EntityEntry entry);
+
+        /// <summary>
+        /// True if the underlying entity is not capable of tracking changes to relationships such that
+        /// DetectChanges is required to do this.
+        /// </summary>
+        bool RequiresRelationshipChangeTracking { get; }
+    }
+}

mcs/class/referencesource/System.Data.Entity/System/Data/Objects/Internal/IPropertyAccessorStrategy.cs

@@ -0,0 +1,56 @@
+//---------------------------------------------------------------------
+// <copyright file="IPropertyAccessorStrategy.cs" company="Microsoft">
+//     Copyright (c) Microsoft Corporation.  All rights reserved.
+// </copyright>
+//---------------------------------------------------------------------
+using System;
+using System.Collections.Generic;
+using System.Text;
+using System.Data.Objects.DataClasses;
+
+namespace System.Data.Objects.Internal
+{
+    /// <summary>
+    /// A strategy interface that defines methods used for setting and getting values of
+    /// properties and collections on entities.
+    /// Implementors of this interface are used by the EntityWrapper class.
+    /// </summary>
+    internal interface IPropertyAccessorStrategy
+    {
+        /// <summary>
+        /// Gets the value of a navigation property for the given related end.
+        /// </summary>
+        /// <param name="relatedEnd">Specifies the related end for which a value is required</param>
+        /// <returns>The property value</returns>
+        object GetNavigationPropertyValue(RelatedEnd relatedEnd);
+
+        /// <summary>
+        /// Sets the value of a navigation property for the given related end.
+        /// </summary>
+        /// <param name="relatedEnd">Specifies the related end for which a value should be set</param>
+        /// <param name="value">The value to set</param>
+        void SetNavigationPropertyValue(RelatedEnd relatedEnd, object value);
+
+        /// <summary>
+        /// Adds a value to the collection represented by the given related end.
+        /// </summary>
+        /// <param name="relatedEnd">The related end for the collection to use</param>
+        /// <param name="value">The value to add to the collection</param>
+        void CollectionAdd(RelatedEnd relatedEnd, object value);
+
+        /// <summary>
+        /// Removes a value from the collection represented by the given related end.
+        /// </summary>
+        /// <param name="relatedEnd">The related end for the collection to use</param>
+        /// <param name="value">The value to remove from the collection</param>
+        /// <returns>True if a value was found and removed; false otherwise</returns>
+        bool CollectionRemove(RelatedEnd relatedEnd, object value);
+
+        /// <summary>
+        /// Creates a new collection for the given related end.
+        /// </summary>
+        /// <param name="relatedEnd">The related end for which a collection should be created</param>
+        /// <returns>The new collection</returns>
+        object CollectionCreate(RelatedEnd relatedEnd);
+    }
+}

mcs/class/referencesource/System.Data.Entity/System/Data/Objects/Internal/LazyLoadBehavior.cs

@@ -0,0 +1,183 @@
+//---------------------------------------------------------------------
+// <copyright file="LazyLoadedCollectionBehavior.cs" company="Microsoft">
+//      Copyright (c) Microsoft Corporation.  All rights reserved.
+// </copyright>
+//
+// @owner       [....]
+// @backupOwner [....]
+//---------------------------------------------------------------------
+
+using System;
+using System.Collections.Generic;
+using System.Diagnostics;
+using System.Linq;
+using System.Linq.Expressions;
+using System.Reflection;
+using System.Reflection.Emit;
+using System.Security;
+using System.Security.Permissions;
+using System.Data.Metadata.Edm;
+using System.Data.Objects.DataClasses;
+using System.Collections;
+
+namespace System.Data.Objects.Internal
+{
+    /// <summary>
+    /// Defines and injects behavior into proxy class Type definitions
+    /// to allow navigation properties to lazily load their references or collection elements.
+    /// </summary>
+    internal sealed class LazyLoadBehavior
+    {
+        /// <summary>
+        /// Return an expression tree that represents the actions required to load the related end
+        /// associated with the intercepted proxy member.
+        /// </summary>
+        /// <param name="member">
+        /// EdmMember that specifies the member to be intercepted.
+        /// </param>
+        /// <param name="property">
+        /// PropertyInfo that specifies the CLR property to be intercepted.
+        /// </param>
+        /// <param name="proxyParameter">
+        /// ParameterExpression that represents the proxy object.
+        /// </param>
+        /// <param name="itemParameter">
+        /// ParameterExpression that represents the proxied property value.
+        /// </param>
+        /// <param name="getEntityWrapperDelegate">The Func that retrieves the wrapper from a proxy</param>
+        /// <returns>
+        /// Expression tree that encapsulates lazy loading behavior for the supplied member,
+        /// or null if the expression tree could not be constructed.
+        /// </returns>
+        internal static Func<TProxy, TItem, bool> GetInterceptorDelegate<TProxy, TItem>(EdmMember member, Func<object, object> getEntityWrapperDelegate) 
+            where TProxy : class
+            where TItem : class 
+        {
+            Func<TProxy, TItem, bool> interceptorDelegate = (proxy, item) => true;
+
+            Debug.Assert(member.BuiltInTypeKind == BuiltInTypeKind.NavigationProperty, "member should represent a navigation property");
+            if (member.BuiltInTypeKind == BuiltInTypeKind.NavigationProperty)
+            {
+                NavigationProperty navProperty = (NavigationProperty)member;
+                RelationshipMultiplicity multiplicity = navProperty.ToEndMember.RelationshipMultiplicity;
+
+                // Given the proxy and item parameters, construct one of the following expressions:
+                //
+                // For collections:
+                //  LazyLoadBehavior.LoadCollection(collection, "relationshipName", "targetRoleName", proxy._entityWrapperField)
+                //
+                // For entity references:
+                //  LazyLoadBehavior.LoadReference(item, "relationshipName", "targetRoleName", proxy._entityWrapperField)
+                //
+                // Both of these expressions return an object of the same type as the first parameter to LoadXYZ method.
+                // In many cases, this will be the first parameter.
+
+                if (multiplicity == RelationshipMultiplicity.Many)
+                {
+                    interceptorDelegate = (proxy, item) => LoadProperty<TItem>(item,
+                                                                               navProperty.RelationshipType.Identity,
+                                                                               navProperty.ToEndMember.Identity,
+                                                                               false,
+                                                                               getEntityWrapperDelegate(proxy));
+                }
+                else
+                {
+                    interceptorDelegate = (proxy, item) => LoadProperty<TItem>(item,
+                                                                               navProperty.RelationshipType.Identity,
+                                                                               navProperty.ToEndMember.Identity,
+                                                                               true,
+                                                                               getEntityWrapperDelegate(proxy));
+                }
+            }
+
+            return interceptorDelegate;
+        }
+
+        /// <summary>
+        /// Determine if the specified member is compatible with lazy loading.
+        /// </summary>
+        /// <param name="ospaceEntityType">
+        /// OSpace EntityType representing a type that may be proxied.
+        /// </param>
+        /// <param name="member">
+        /// Member of the <paramref name="ospaceEntityType" /> to be examined.
+        /// </param>
+        /// <returns>
+        /// True if the member is compatible with lazy loading; otherwise false.
+        /// </returns>
+        /// <remarks>
+        /// To be compatible with lazy loading, 
+        /// a member must meet the criteria for being able to be proxied (defined elsewhere),
+        /// and must be a navigation property.
+        /// In addition, for relationships with a multiplicity of Many,
+        /// the property type must be an implementation of ICollection&lt;T&gt;.
+        /// </remarks>
+        internal static bool IsLazyLoadCandidate(EntityType ospaceEntityType, EdmMember member)
+        {
+            Debug.Assert(ospaceEntityType.DataSpace == DataSpace.OSpace, "ospaceEntityType.DataSpace must be OSpace");
+
+            bool isCandidate = false;
+
+            if (member.BuiltInTypeKind == BuiltInTypeKind.NavigationProperty)
+            {
+                NavigationProperty navProperty = (NavigationProperty)member;
+                RelationshipMultiplicity multiplicity = navProperty.ToEndMember.RelationshipMultiplicity;
+
+                PropertyInfo propertyInfo = EntityUtil.GetTopProperty(ospaceEntityType.ClrType, member.Name);
+                Debug.Assert(propertyInfo != null, "Should have found lazy loading property");
+                Type propertyValueType = propertyInfo.PropertyType;
+
+                if (multiplicity == RelationshipMultiplicity.Many)
+                {
+                    Type elementType;
+                    isCandidate = EntityUtil.TryGetICollectionElementType(propertyValueType, out elementType);
+                }
+                else if (multiplicity == RelationshipMultiplicity.One || multiplicity == RelationshipMultiplicity.ZeroOrOne)
+                {
+                    // This is an EntityReference property.
+                    isCandidate = true;
+                }
+            }
+
+            return isCandidate;
+        }
+
+        /// <summary>
+        /// Method called by proxy interceptor delegate to provide lazy loading behavior for navigation properties.
+        /// </summary>
+        /// <typeparam name="TItem">property type</typeparam>
+        /// <param name="propertyValue">The property value whose associated relationship is to be loaded.</param>
+        /// <param name="relationshipName">String name of the relationship.</param>
+        /// <param name="targetRoleName">String name of the related end to be loaded for the relationship specified by <paramref name="relationshipName"/>.</param>
+        /// <param name="wrapperObject">Entity wrapper object used to retrieve RelationshipManager for the proxied entity.</param>
+        /// <returns>
+        /// True if the value instance was mutated and can be returned
+        /// False if the class should refetch the value because the instance has changed
+        /// </returns>
+        private static bool LoadProperty<TItem>(TItem propertyValue, string relationshipName, string targetRoleName, bool mustBeNull, object wrapperObject) where TItem : class
+        {
+            // Only attempt to load collection if:
+            //
+            // 1. Collection is non-null.
+            // 2. ObjectContext.ContextOptions.LazyLoadingEnabled is true
+            // 3. A non-null RelationshipManager can be retrieved (this is asserted).
+            // 4. The EntityCollection is not already loaded.
+
+            Debug.Assert(wrapperObject == null || wrapperObject is IEntityWrapper, "wrapperObject must be an IEntityWrapper");
+            IEntityWrapper wrapper = (IEntityWrapper)wrapperObject; // We want an exception if the cast fails.
+
+            if (wrapper != null && wrapper.Context != null)
+            {
+                RelationshipManager relationshipManager = wrapper.RelationshipManager;
+                Debug.Assert(relationshipManager != null, "relationshipManager should be non-null");
+                if (relationshipManager != null && (!mustBeNull || propertyValue == null))
+                {
+                    RelatedEnd relatedEnd = relationshipManager.GetRelatedEndInternal(relationshipName, targetRoleName);
+                    relatedEnd.DeferredLoad();
+                }
+            }
+
+            return propertyValue != null;
+        }
+    }
+}

mcs/class/referencesource/System.Data.Entity/System/Data/Objects/Internal/LightweightEntityWrapper.cs

@@ -0,0 +1,170 @@
+//---------------------------------------------------------------------
+// <copyright file="LightweightEntityWrapper.cs" company="Microsoft">
+//      Copyright (c) Microsoft Corporation.  All rights reserved.
+// </copyright>
+//
+// @owner       [....]
+// @backupOwner [....]
+//---------------------------------------------------------------------
+using System.Collections;
+using System.Data.Objects.DataClasses;
+using System.Diagnostics;
+using System.Reflection;
+using System.Data.Metadata.Edm;
+
+namespace System.Data.Objects.Internal
+{
+    /// <summary>
+    /// Implementation of IEntityWrapper for any entity that implements IEntityWithChangeTracker, IEntityWithRelationships, 
+    /// and IEntityWithKey and is not a proxy.  This is a lightweight wrapper that delegates functionality to those iterfaces.
+    /// This improves the speed and memory utilization for the standard code-gen cases in materialization.
+    /// </summary>
+    /// <typeparam name="TEntity">The type of entity wrapped</typeparam>
+    internal sealed class LightweightEntityWrapper<TEntity> : BaseEntityWrapper<TEntity>
+             where TEntity : IEntityWithRelationships, IEntityWithKey, IEntityWithChangeTracker
+    {
+        private readonly TEntity _entity;
+
+        /// <summary>
+        /// Constructs a wrapper for the given entity.
+        /// Note: use EntityWrapperFactory instead of calling this constructor directly.
+        /// </summary>
+        /// <param name="entity">The entity to wrap</param>
+        internal LightweightEntityWrapper(TEntity entity)
+        : base(entity, entity.RelationshipManager)
+        {
+            Debug.Assert(entity is IEntityWithChangeTracker, "LightweightEntityWrapper only works with entities that implement IEntityWithChangeTracker");
+            Debug.Assert(entity is IEntityWithRelationships, "LightweightEntityWrapper only works with entities that implement IEntityWithRelationships");
+            Debug.Assert(entity is IEntityWithKey, "LightweightEntityWrapper only works with entities that implement IEntityWithKey");
+            Debug.Assert(!EntityProxyFactory.IsProxyType(entity.GetType()), "LightweightEntityWrapper only works with entities that are not proxies");
+            _entity = entity;
+        }
+
+        /// <summary>
+        /// Constructs a wrapper as part of the materialization process.  This constructor is only used
+        /// during materialization where it is known that the entity being wrapped is newly constructed.
+        /// This means that some checks are not performed that might be needed when thw wrapper is
+        /// created at other times, and information such as the identity type is passed in because
+        /// it is readily available in the materializer.
+        /// </summary>
+        /// <param name="entity">The entity to wrap</param>
+        /// <param name="key">The key for the entity</param>
+        /// <param name="entitySet">The entity set, or null if none is known</param>
+        /// <param name="context">The context to which the entity should be attached</param>
+        /// <param name="mergeOption">NoTracking for non-tracked entities, AppendOnly otherwise</param>
+        /// <param name="identityType">The type of the entity ignoring any possible proxy type</param>
+        internal LightweightEntityWrapper(TEntity entity, EntityKey key, EntitySet entitySet, ObjectContext context, MergeOption mergeOption, Type identityType)
+            : base(entity, entity.RelationshipManager, entitySet, context, mergeOption, identityType)
+        {
+            Debug.Assert(entity is IEntityWithChangeTracker, "LightweightEntityWrapper only works with entities that implement IEntityWithChangeTracker");
+            Debug.Assert(entity is IEntityWithRelationships, "LightweightEntityWrapper only works with entities that implement IEntityWithRelationships");
+            Debug.Assert(entity is IEntityWithKey, "LightweightEntityWrapper only works with entities that implement IEntityWithKey");
+            Debug.Assert(!EntityProxyFactory.IsProxyType(entity.GetType()), "LightweightEntityWrapper only works with entities that are not proxies");
+            _entity = entity;
+            _entity.EntityKey = key;
+        }
+
+        // See IEntityWrapper documentation
+        public override void SetChangeTracker(IEntityChangeTracker changeTracker)
+        {
+            _entity.SetChangeTracker(changeTracker);
+        }
+
+        // See IEntityWrapper documentation
+        public override void TakeSnapshot(EntityEntry entry)
+        {
+        }
+
+        // See IEntityWrapper documentation
+        public override void TakeSnapshotOfRelationships(EntityEntry entry)
+        {
+        }
+
+        // See IEntityWrapper documentation
+        public override EntityKey EntityKey
+        {
+            get
+            {
+                return _entity.EntityKey;
+            }
+            set
+            {
+                _entity.EntityKey = value;
+            }
+        }
+
+        public override bool OwnsRelationshipManager
+        {
+            get { return true; }
+        }
+
+        // See IEntityWrapper documentation
+        public override EntityKey GetEntityKeyFromEntity()
+        {
+            return _entity.EntityKey;
+        }
+
+        // See IEntityWrapper documentation
+        public override void CollectionAdd(RelatedEnd relatedEnd, object value)
+        {
+        }
+
+        // See IEntityWrapper documentation
+        public override bool CollectionRemove(RelatedEnd relatedEnd, object value)
+        {
+            return false;
+        }
+        
+        // See IEntityWrapper documentation
+        public override void SetNavigationPropertyValue(RelatedEnd relatedEnd, object value)
+        {
+        }
+
+        // See IEntityWrapper documentation
+        public override void RemoveNavigationPropertyValue(RelatedEnd relatedEnd, object value)
+        {
+        }
+
+        // See IEntityWrapper documentation
+        public override void EnsureCollectionNotNull(RelatedEnd relatedEnd)
+        {
+        }
+
+        // See IEntityWrapper documentation
+        public override object GetNavigationPropertyValue(RelatedEnd relatedEnd)
+        {
+            return null;
+        }
+
+        // See IEntityWrapper documentation
+        public override object Entity
+        {
+            get { return _entity; }
+        }
+
+        // See IEntityWrapper<TEntity> documentation
+        public override TEntity TypedEntity
+        {
+            get { return _entity; }
+        }
+
+        // See IEntityWrapper documentation
+        public override void SetCurrentValue(EntityEntry entry, StateManagerMemberMetadata member, int ordinal, object target, object value)
+        {
+            member.SetValue(target, value);
+        }
+
+        // See IEntityWrapper documentation
+        public override void UpdateCurrentValueRecord(object value, EntityEntry entry)
+        {
+            // No extra work to do because we know that the entity is not a proxy and has a change tracker
+            entry.UpdateRecordWithoutSetModified(value, entry.CurrentValues);
+        }
+
+        // See IEntityWrapper documentation
+        public override bool RequiresRelationshipChangeTracking
+        {
+            get { return false; }
+        }
+    }
+}

mcs/class/referencesource/System.Data.Entity/System/Data/Objects/Internal/NullEntityWrapper.cs

@@ -0,0 +1,207 @@
+//---------------------------------------------------------------------
+// <copyright file="NullEntityWrapper.cs" company="Microsoft">
+//      Copyright (c) Microsoft Corporation.  All rights reserved.
+// </copyright>
+//
+// @owner       [....]
+// @backupOwner [....]
+//---------------------------------------------------------------------
+namespace System.Data.Objects.Internal
+{
+    using System.Data.Metadata.Edm;
+    using System.Data.Objects.DataClasses;
+    using System.Diagnostics;
+
+    /// <summary>
+    /// Defines an entity wrapper that wraps an entity with a null value.
+    /// This is a singleton class for which the same instance is always returned
+    /// any time a wrapper around a null entity is requested.  Objects of this
+    /// type are immutable and mutable to allow this behavior to work correctly.
+    /// </summary>
+    internal class NullEntityWrapper : IEntityWrapper
+    {
+        private static IEntityWrapper s_nullWrapper = new NullEntityWrapper();
+
+        // Private constructor prevents anyone else from creating an instance
+        private NullEntityWrapper()
+        {
+        }
+
+        /// <summary>
+        /// The single instance of this class.
+        /// </summary>
+        internal static IEntityWrapper NullWrapper
+        {
+            get { return s_nullWrapper; }
+        }
+
+        public RelationshipManager RelationshipManager
+        {
+            get
+            {
+                Debug.Fail("Cannot access RelationshipManager from null wrapper.");
+                return null;
+            }
+        }
+
+        public bool OwnsRelationshipManager
+        {
+            get
+            {
+                Debug.Fail("Cannot access RelationshipManager from null wrapper.");
+                return false;
+            }
+        }
+
+        public object Entity
+        {
+            get { return null; }
+        }
+
+        public EntityEntry ObjectStateEntry
+        {
+            get { return null; }
+            set { }
+        }
+
+        public void CollectionAdd(RelatedEnd relatedEnd, object value)
+        {
+            Debug.Fail("Cannot modify collection from null wrapper.");
+        }
+
+        public bool CollectionRemove(RelatedEnd relatedEnd, object value)
+        {
+            Debug.Fail("Cannot modify collection from null wrapper.");
+            return false;
+        }
+
+        public EntityKey EntityKey
+        {
+            get
+            {
+                Debug.Fail("Cannot access EntityKey from null wrapper.");
+                return null;
+            }
+            set
+            {
+                Debug.Fail("Cannot access EntityKey from null wrapper.");
+            }
+        }
+
+        public EntityKey GetEntityKeyFromEntity()
+        {
+            Debug.Assert(false, "Method on NullEntityWrapper should not be called");
+            return null;
+        }
+
+        public ObjectContext Context
+        {
+            get
+            {
+                Debug.Fail("Cannot access Context from null wrapper.");
+                return null;
+            }
+            set
+            {
+                Debug.Fail("Cannot access Context from null wrapper.");
+            }
+        }
+
+        public MergeOption MergeOption
+        {
+            get
+            {
+                Debug.Fail("Cannot access MergeOption from null wrapper.");
+                return MergeOption.NoTracking;
+            }
+        }
+
+        public void AttachContext(ObjectContext context, EntitySet entitySet, MergeOption mergeOption)
+        {
+            Debug.Fail("Cannot access Context from null wrapper.");
+        }
+
+        public void ResetContext(ObjectContext context, EntitySet entitySet, MergeOption mergeOption)
+        {
+            Debug.Fail("Cannot access Context from null wrapper.");
+        }
+
+        public void DetachContext()
+        {
+            Debug.Fail("Cannot access Context from null wrapper.");
+        }
+
+        public void SetChangeTracker(IEntityChangeTracker changeTracker)
+        {
+            Debug.Fail("Cannot access ChangeTracker from null wrapper.");
+        }
+
+        public void TakeSnapshot(EntityEntry entry)
+        {
+            Debug.Fail("Cannot take snapshot of using null wrapper.");
+        }
+
+        public void TakeSnapshotOfRelationships(EntityEntry entry)
+        {
+            Debug.Fail("Cannot take snapshot using null wrapper.");
+        }
+
+        public Type IdentityType
+        {
+            get
+            {
+                Debug.Fail("Cannot access IdentityType from null wrapper.");
+                return null;
+            }
+        }
+
+        public void EnsureCollectionNotNull(RelatedEnd relatedEnd)
+        {
+            Debug.Fail("Cannot modify collection from null wrapper.");
+        }
+
+        public object GetNavigationPropertyValue(RelatedEnd relatedEnd)
+        {
+            Debug.Fail("Cannot access property using null wrapper.");
+            return null;
+        }
+
+        public void SetNavigationPropertyValue(RelatedEnd relatedEnd, object value)
+        {
+            Debug.Fail("Cannot access property using null wrapper.");
+        }
+
+        public void RemoveNavigationPropertyValue(RelatedEnd relatedEnd, object value)
+        {
+            Debug.Fail("Cannot access property using null wrapper.");
+        }
+
+        public void SetCurrentValue(EntityEntry entry, StateManagerMemberMetadata member, int ordinal, object target, object value)
+        {
+            Debug.Fail("Cannot set a value onto a null entity.");
+        }
+
+        public bool InitializingProxyRelatedEnds
+        {
+            get
+            { 
+                Debug.Fail("Cannot access flag on null wrapper.");
+                return false;
+            }
+            set
+            {
+                Debug.Fail("Cannot access flag on null wrapper.");
+            }
+        }
+
+        public void UpdateCurrentValueRecord(object value, EntityEntry entry)
+        {
+            Debug.Fail("Cannot UpdateCurrentValueRecord on a null entity."); 
+        }
+
+        public bool RequiresRelationshipChangeTracking
+        {
+            get { return false; }
+        }
+    }
+}

mcs/class/referencesource/System.Data.Entity/System/Data/Objects/Internal/ObjectFullSpanRewriter.cs

@@ -0,0 +1,263 @@
+//---------------------------------------------------------------------
+// <copyright file="ObjectFullSpanRewriter.cs" company="Microsoft">
+//      Copyright (c) Microsoft Corporation.  All rights reserved.
+// </copyright>
+//
+// @owner [....]
+// @backupowner [....]
+//---------------------------------------------------------------------
+
+namespace System.Data.Objects.Internal
+{
+    using System.Collections.Generic;
+    using System.Data.Common.CommandTrees;
+    using System.Data.Common.CommandTrees.ExpressionBuilder;
+    using System.Data.Common.Utils;
+    using System.Data.Metadata.Edm;
+    using System.Diagnostics;
+
+    internal class ObjectFullSpanRewriter : ObjectSpanRewriter
+    {
+        /// <summary>
+        /// Represents a node in the 'Include' navigation property tree
+        /// built from the list of SpanPaths on the Span object with which
+        /// the FullSpanRewriter is constructed.
+        /// </summary>
+        private class SpanPathInfo
+        {
+            internal SpanPathInfo(EntityType declaringType)
+            {
+                this.DeclaringType = declaringType;
+            }
+
+            /// <summary>
+            /// The effective Entity type of this node in the tree
+            /// </summary>
+            internal EntityType DeclaringType;
+
+            /// <summary>
+            /// Describes the navigation properties that should be retrieved
+            /// from this node in the tree and the Include sub-paths that extend
+            /// from each of those navigation properties
+            /// </summary>
+            internal Dictionary<NavigationProperty, SpanPathInfo> Children;
+        }
+
+        /// <summary>
+        /// Maintains a reference to the SpanPathInfo tree node representing the
+        /// current position in the 'Include' path that is currently being expanded.
+        /// </summary>
+        private Stack<SpanPathInfo> _currentSpanPath = new Stack<SpanPathInfo>();
+
+        internal ObjectFullSpanRewriter(DbCommandTree tree, DbExpression toRewrite, Span span, AliasGenerator aliasGenerator)
+            : base(tree, toRewrite, aliasGenerator)
+        {
+            Debug.Assert(span != null, "Span cannot be null");
+            Debug.Assert(span.SpanList.Count > 0, "At least one span path is required");
+
+            // Retrieve the effective 'T' of the ObjectQuery<T> that produced
+            // the Command Tree that is being rewritten. This could be either
+            // literally 'T' or Collection<T>.
+            EntityType entityType = null;
+            if (!TryGetEntityType(this.Query.ResultType, out entityType))
+            {
+                // If the result type of the query is neither an Entity type nor a collection
+                // type with an Entity element type, then full Span is currently not allowed.
+                throw EntityUtil.InvalidOperation(System.Data.Entity.Strings.ObjectQuery_Span_IncludeRequiresEntityOrEntityCollection);
+            }
+
+            // Construct the SpanPathInfo navigation property tree using the
+            // list of Include Span paths from the Span object:
+            // Create a SpanPathInfo instance that represents the root of the tree
+            // and takes its Entity type from the Entity type of the result type of the query.
+            SpanPathInfo spanRoot = new SpanPathInfo(entityType);
+            
+            // Populate the tree of navigation properties based on the navigation property names
+            // in the Span paths from the Span object. Commonly rooted span paths are merged, so
+            // that paths of "Customer.Order" and "Customer.Address", for example, will share a
+            // common SpanPathInfo for "Customer" in the Children collection of the root SpanPathInfo,
+            // and that SpanPathInfo will contain one child for "Order" and another for "Address".
+            foreach (Span.SpanPath path in span.SpanList)
+            {
+                AddSpanPath(spanRoot, path.Navigations);
+            }
+
+            // The 'current' span path is initialized to the root of the Include span tree
+            _currentSpanPath.Push(spanRoot);
+        }
+
+        /// <summary>
+        /// Populates the Include span tree with appropriate branches for the Include path
+        /// represented by the specified list of navigation property names.
+        /// </summary>
+        /// <param name="parentInfo">The root SpanPathInfo</param>
+        /// <param name="navPropNames">A list of navigation property names that describes a single Include span path</param>
+        private void AddSpanPath(SpanPathInfo parentInfo, List<string> navPropNames)
+        {
+            ConvertSpanPath(parentInfo, navPropNames, 0);
+        }
+
+        private void ConvertSpanPath(SpanPathInfo parentInfo, List<string> navPropNames, int pos)
+        {
+            // Attempt to retrieve the next navigation property from the current entity type
+            // using the name of the current navigation property in the Include path.
+            NavigationProperty nextNavProp = null;
+            if (!parentInfo.DeclaringType.NavigationProperties.TryGetValue(navPropNames[pos], true, out nextNavProp))
+            {
+                // The navigation property name is not valid for this Entity type
+                throw EntityUtil.InvalidOperation(System.Data.Entity.Strings.ObjectQuery_Span_NoNavProp(parentInfo.DeclaringType.FullName, navPropNames[pos]));
+            }
+
+            // The navigation property was retrieved, an entry for it must be ensured in the Children
+            // collection of the parent SpanPathInfo instance.
+            // If the parent's Children collection does not exist then instantiate it now:
+            if (null == parentInfo.Children)
+            {
+                parentInfo.Children = new Dictionary<NavigationProperty, SpanPathInfo>();
+            }
+
+            // If a sub-path that begins with the current navigation property name was already
+            // encountered, then a SpanPathInfo for this navigation property may already exist
+            // in the Children dictionary...
+            SpanPathInfo nextChild = null;
+            if (!parentInfo.Children.TryGetValue(nextNavProp, out nextChild))
+            {
+                // ... otherwise, create a new SpanPathInfo instance that this navigation
+                // property maps to and ensure its presence in the Children dictionary.
+                nextChild = new SpanPathInfo(EntityTypeFromResultType(nextNavProp));
+                parentInfo.Children[nextNavProp] = nextChild;
+            }
+
+            // If this navigation property is not the end of the span path then
+            // increment the position and recursively call ConvertSpanPath, specifying
+            // the (retrieved or newly-created) SpanPathInfo of this navigation property
+            // as the new 'parent' info.
+            if (pos < navPropNames.Count - 1)
+            {
+                ConvertSpanPath(nextChild, navPropNames, pos + 1);
+            }
+        }
+
+        /// <summary>
+        /// Retrieves the Entity (result or element) type produced by a Navigation Property.
+        /// </summary>
+        /// <param name="navProp">The navigation property</param>
+        /// <returns>
+        ///     The Entity type produced by the navigation property. 
+        ///     This may be the immediate result type (if the result is at most one)
+        ///     or the element type of the result type, otherwise.
+        /// </returns>
+        private static EntityType EntityTypeFromResultType(NavigationProperty navProp)
+        {
+            EntityType retType = null;
+            TryGetEntityType(navProp.TypeUsage, out retType);
+            // Currently, navigation properties may only return an Entity or Collection<Entity> result
+            Debug.Assert(retType != null, "Navigation property has non-Entity and non-Entity collection result type?");
+            return retType;
+        }
+
+        /// <summary>
+        /// Retrieves the Entity (result or element) type referenced by the specified TypeUsage, if
+        /// its EdmType is an Entity type or a collection type with an Entity element type.
+        /// </summary>
+        /// <param name="resultType">The TypeUsage that provides the EdmType to examine</param>
+        /// <param name="entityType">The referenced Entity (element) type, if present.</param>
+        /// <returns>
+        ///     <c>true</c> if the specified <paramref name="resultType"/> is an Entity type or a 
+        ///     collection type with an Entity element type; otherwise <c>false</c>.
+        /// </returns>
+        private static bool TryGetEntityType(TypeUsage resultType, out EntityType entityType)
+        {
+            // If the result type is an Entity, then simply use that type.
+            if (BuiltInTypeKind.EntityType == resultType.EdmType.BuiltInTypeKind)
+            {
+                entityType = (EntityType)resultType.EdmType;
+                return true;
+            }
+            else if (BuiltInTypeKind.CollectionType == resultType.EdmType.BuiltInTypeKind)
+            {
+                // If the result type of the query is a collection, attempt to extract
+                // the element type of the collection and determine if it is an Entity type.
+                EdmType elementType = ((CollectionType)resultType.EdmType).TypeUsage.EdmType;
+                if (BuiltInTypeKind.EntityType == elementType.BuiltInTypeKind)
+                {
+                    entityType = (EntityType)elementType;
+                    return true;
+                }
+            }
+
+            entityType = null;
+            return false;
+        }
+
+        /// <summary>
+        /// Utility method to retrieve the 'To' AssociationEndMember of a NavigationProperty
+        /// </summary>
+        /// <param name="property">The navigation property</param>
+        /// <returns>The AssociationEndMember that is the target of the navigation operation represented by the NavigationProperty</returns>
+        private AssociationEndMember GetNavigationPropertyTargetEnd(NavigationProperty property)
+        {
+            AssociationType relationship = this.Metadata.GetItem<AssociationType>(property.RelationshipType.FullName, DataSpace.CSpace);
+            Debug.Assert(relationship.AssociationEndMembers.Contains(property.ToEndMember.Name), "Association does not declare member referenced by Navigation property?");
+            return relationship.AssociationEndMembers[property.ToEndMember.Name];
+        }
+
+        internal override SpanTrackingInfo CreateEntitySpanTrackingInfo(DbExpression expression, EntityType entityType)
+        {
+            SpanTrackingInfo tracking = new SpanTrackingInfo();
+
+            SpanPathInfo currentInfo = _currentSpanPath.Peek();
+            if (currentInfo.Children != null)
+            {
+                // The current SpanPathInfo instance on the top of the span path stack indicates
+                // which navigation properties should be retrieved from this Entity-typed expression
+                // and also specifies (in the form of child SpanPathInfo instances) which sub-paths
+                // must be expanded for each of those navigation properties.
+                // The SpanPathInfo instance may be the root instance or a SpanPathInfo that represents a sub-path.
+                int idx = 1; // SpanRoot is always the first (zeroth) column, full- and relationship-span columns follow.
+                foreach (KeyValuePair<NavigationProperty, SpanPathInfo> nextInfo in currentInfo.Children)
+                {
+                    // If the tracking information was not initialized yet, do so now.
+                    if (null == tracking.ColumnDefinitions)
+                    {
+                        tracking = InitializeTrackingInfo(this.RelationshipSpan);
+                    }
+
+                    // Create a property expression that retrieves the specified navigation property from the Entity-typed expression.
+                    // Note that the expression is cloned since it may be used as the instance of multiple property expressions.
+                    DbExpression columnDef = expression.Property(nextInfo.Key);
+
+                    // Rewrite the result of the navigation property. This is required for two reasons:
+                    // 1. To continue spanning the current Include path.
+                    // 2. To apply relationship span to the Entity or EntityCollection produced by the navigation property, if necessary.
+                    //    Consider an Include path of "Order" for a query that returns OrderLines - the Include'd Orders should have
+                    //    their associated Customer relationship spanned.
+                    // Note that this will recursively call this method with the Entity type of the result of the
+                    // navigation property, which will in turn call loop through the sub-paths of this navigation
+                    // property and adjust the stack to track which Include path is being expanded and which 
+                    // element of that path is considered 'current'.
+                    _currentSpanPath.Push(nextInfo.Value);
+                    columnDef = this.Rewrite(columnDef);
+                    _currentSpanPath.Pop();
+
+                    // Add a new column to the tracked columns using the rewritten column definition
+                    tracking.ColumnDefinitions.Add(new KeyValuePair<string, DbExpression>(tracking.ColumnNames.Next(), columnDef));
+                    AssociationEndMember targetEnd = GetNavigationPropertyTargetEnd(nextInfo.Key);
+                    tracking.SpannedColumns[idx] = targetEnd;
+
+                    // If full span and relationship span are both required, a relationship span may be rendered
+                    // redundant by an already added full span. Therefore the association ends that have been expanded
+                    // as part of full span are tracked using a dictionary.
+                    if (this.RelationshipSpan)
+                    {
+                        tracking.FullSpannedEnds[targetEnd] = true;
+                    }
+
+                    idx++;
+                }
+            }
+
+            return tracking;
+        }
+    }
+}

mcs/class/referencesource/System.Data.Entity/System/Data/Objects/Internal/ObjectQueryExecutionPlan.cs

@@ -0,0 +1,229 @@
+//---------------------------------------------------------------------
+// <copyright file="ObjectQueryExecutionPlan.cs" company="Microsoft">
+//      Copyright (c) Microsoft Corporation.  All rights reserved.
+// </copyright>
+//
+// @owner  [....]
+//---------------------------------------------------------------------
+
+namespace System.Data.Objects.Internal
+{
+    using System;
+    using System.Data.Common;
+    using System.Data.Common.CommandTrees;
+    using System.Data.Common.Internal.Materialization;
+    using System.Data.Common.QueryCache;
+    using System.Data.Common.Utils;
+    using System.Data.EntityClient;
+    using System.Data.Metadata.Edm;
+    using System.Data.Objects;
+    using System.Diagnostics;
+    using CompiledQueryParameters = System.Collections.ObjectModel.ReadOnlyCollection<System.Collections.Generic.KeyValuePair<ObjectParameter, System.Data.Objects.ELinq.QueryParameterExpression>>;
+    
+    /// <summary>
+    /// Represents the 'compiled' form of all elements (query + result assembly) required to execute a specific <see cref="ObjectQuery"/>
+    /// </summary>
+    internal sealed class ObjectQueryExecutionPlan
+    {
+        internal readonly DbCommandDefinition CommandDefinition;
+        internal readonly ShaperFactory ResultShaperFactory;
+        internal readonly TypeUsage ResultType;
+        internal readonly MergeOption MergeOption;
+        internal readonly CompiledQueryParameters CompiledQueryParameters;
+        
+        /// <summary>If the query yields entities from a single entity set, the value is stored here.</summary>
+        private readonly EntitySet _singleEntitySet;
+
+        private ObjectQueryExecutionPlan(DbCommandDefinition commandDefinition, ShaperFactory resultShaperFactory, TypeUsage resultType, MergeOption mergeOption, EntitySet singleEntitySet, CompiledQueryParameters compiledQueryParameters)
+        {
+            Debug.Assert(commandDefinition != null, "A command definition is required");
+            Debug.Assert(resultShaperFactory != null, "A result shaper factory is required");
+            Debug.Assert(resultType != null, "A result type is required");
+
+            this.CommandDefinition = commandDefinition;
+            this.ResultShaperFactory = resultShaperFactory;
+            this.ResultType = resultType;
+            this.MergeOption = mergeOption;
+            this._singleEntitySet = singleEntitySet;
+            this.CompiledQueryParameters = compiledQueryParameters;
+        }
+
+        internal static ObjectQueryExecutionPlan Prepare(ObjectContext context, DbQueryCommandTree tree, Type elementType, MergeOption mergeOption, Span span, CompiledQueryParameters compiledQueryParameters, AliasGenerator aliasGenerator)
+        {
+            TypeUsage treeResultType = tree.Query.ResultType;
+
+            // Rewrite this tree for Span?
+            DbExpression spannedQuery = null;
+            SpanIndex spanInfo;
+            if (ObjectSpanRewriter.TryRewrite(tree, span, mergeOption, aliasGenerator, out spannedQuery, out spanInfo))
+            {
+                tree = DbQueryCommandTree.FromValidExpression(tree.MetadataWorkspace, tree.DataSpace, spannedQuery);
+            }
+            else
+            {
+                spanInfo = null;
+            }
+
+            DbConnection connection = context.Connection;
+            DbCommandDefinition definition = null;
+
+            // The connection is required to get to the CommandDefinition builder.
+            if (connection == null)
+            {
+                throw EntityUtil.InvalidOperation(System.Data.Entity.Strings.ObjectQuery_InvalidConnection);
+            }
+                        
+            DbProviderServices services = DbProviderServices.GetProviderServices(connection);
+
+            try
+            {
+                definition = services.CreateCommandDefinition(tree);
+            }
+            catch (EntityCommandCompilationException)
+            {
+                // If we're running against EntityCommand, we probably already caught the providers'
+                // exception and wrapped it, we don't want to do that again, so we'll just rethrow
+                // here instead.
+                throw;
+            }
+            catch (Exception e)
+            {
+                // we should not be wrapping all exceptions
+                if (EntityUtil.IsCatchableExceptionType(e))
+                {
+                    // we don't wan't folks to have to know all the various types of exceptions that can 
+                    // occur, so we just rethrow a CommandDefinitionException and make whatever we caught  
+                    // the inner exception of it.
+                    throw EntityUtil.CommandCompilation(System.Data.Entity.Strings.EntityClient_CommandDefinitionPreparationFailed, e);
+                }
+                throw;
+            }
+
+            if (definition == null)
+            {
+                throw EntityUtil.ProviderDoesNotSupportCommandTrees();
+            }
+
+            EntityCommandDefinition entityDefinition = (EntityCommandDefinition)definition;
+            QueryCacheManager cacheManager = context.Perspective.MetadataWorkspace.GetQueryCacheManager();
+            
+            ShaperFactory shaperFactory = ShaperFactory.Create(elementType, cacheManager, entityDefinition.CreateColumnMap(null),
+                context.MetadataWorkspace, spanInfo, mergeOption, false);
+
+            // attempt to determine entity information for this query (e.g. which entity type and which entity set)
+            //EntityType rootEntityType = null;
+
+            EntitySet singleEntitySet = null;
+
+            if (treeResultType.EdmType.BuiltInTypeKind == BuiltInTypeKind.CollectionType)
+            {
+                // determine if the entity set is unambiguous given the entity type
+                if (null != entityDefinition.EntitySets)
+                {
+                    foreach (EntitySet entitySet in entityDefinition.EntitySets)
+                    {
+                        if (null != entitySet)
+                        {
+                            if (entitySet.ElementType.IsAssignableFrom(((CollectionType)treeResultType.EdmType).TypeUsage.EdmType))
+                            {
+                                if (singleEntitySet == null)
+                                {
+                                    // found a single match
+                                    singleEntitySet = entitySet;
+                                }
+                                else
+                                {
+                                    // there's more than one matching entity set
+                                    singleEntitySet = null;
+                                    break;
+                                }
+                            }
+                        }
+                    }
+                }
+            }
+
+            return new ObjectQueryExecutionPlan(definition, shaperFactory, treeResultType, mergeOption, singleEntitySet, compiledQueryParameters);
+        }
+
+        internal string ToTraceString()
+        {
+            string traceString = string.Empty;
+            EntityCommandDefinition entityCommandDef = this.CommandDefinition as EntityCommandDefinition;
+            if (entityCommandDef != null)
+            {
+                traceString = entityCommandDef.ToTraceString();
+            }
+            return traceString;
+        }
+
+        internal ObjectResult<TResultType> Execute<TResultType>(ObjectContext context, ObjectParameterCollection parameterValues)
+        {
+            DbDataReader storeReader = null;
+            try
+            {
+                // create entity command (just do this to snarf store command)
+                EntityCommandDefinition commandDefinition = (EntityCommandDefinition)this.CommandDefinition;
+                EntityCommand entityCommand = new EntityCommand((EntityConnection)context.Connection, commandDefinition);
+
+                // pass through parameters and timeout values
+                if (context.CommandTimeout.HasValue)
+                {
+                    entityCommand.CommandTimeout = context.CommandTimeout.Value;
+                }
+
+                if (parameterValues != null)
+                {
+                    foreach (ObjectParameter parameter in parameterValues)
+                    {
+                        int index = entityCommand.Parameters.IndexOf(parameter.Name);
+
+                        if (index != -1)
+                        {
+                            entityCommand.Parameters[index].Value = parameter.Value ?? DBNull.Value;
+                        }
+                    }
+                }
+
+                // acquire store reader
+                storeReader = commandDefinition.ExecuteStoreCommands(entityCommand, CommandBehavior.Default);
+
+                ShaperFactory<TResultType> shaperFactory = (ShaperFactory<TResultType>)this.ResultShaperFactory;
+                Shaper<TResultType> shaper = shaperFactory.Create(storeReader, context, context.MetadataWorkspace, this.MergeOption, true);
+
+                // create materializer delegate
+                TypeUsage resultItemEdmType;
+
+                if (ResultType.EdmType.BuiltInTypeKind == BuiltInTypeKind.CollectionType)
+                {
+                    resultItemEdmType = ((CollectionType)ResultType.EdmType).TypeUsage;
+                }
+                else
+                {
+                    resultItemEdmType = ResultType;
+                }
+
+                return new ObjectResult<TResultType>(shaper, this._singleEntitySet, resultItemEdmType);
+            }
+            catch (Exception)
+            {
+                if (null != storeReader)
+                {
+                    // Note: The caller is responsible for disposing reader if creating
+                    // the enumerator fails.
+                    storeReader.Dispose();
+                }
+                throw;
+            }
+        }
+
+        internal static ObjectResult<TResultType> ExecuteCommandTree<TResultType>(ObjectContext context, DbQueryCommandTree query, MergeOption mergeOption)
+        {
+            Debug.Assert(context != null, "ObjectContext cannot be null");
+            Debug.Assert(query != null, "Command tree cannot be null");
+
+            ObjectQueryExecutionPlan execPlan = ObjectQueryExecutionPlan.Prepare(context, query, typeof(TResultType), mergeOption, null, null, System.Data.Common.CommandTrees.ExpressionBuilder.DbExpressionBuilder.AliasGenerator);
+            return execPlan.Execute<TResultType>(context, null);
+        }
+    }
+}