//--------------------------------------------------------------------- // // Copyright (c) Microsoft Corporation. All rights reserved. // // @owner Microsoft // @backupOwner Microsoft //--------------------------------------------------------------------- using System.Collections.Generic; using System.Data.Common.CommandTrees; using System.Data.Common.Utils; using System.Data.Entity; using System.Data.Mapping.ViewGeneration; using System.Data.Metadata.Edm; using System.Diagnostics; using System.Linq; using System.Reflection; // All methods prefixed with 'Serialized' have locked access through the shared Memoizer. Do not call it from outside the Memoizer's scope. namespace System.Data.Mapping { using System.Data.Common.CommandTrees.ExpressionBuilder; using OfTypeQVCacheKey = Pair>; public partial class StorageMappingItemCollection : MappingItemCollection { internal delegate bool TryGetUserDefinedQueryView(EntitySetBase extent, out GeneratedView generatedView); internal delegate bool TryGetUserDefinedQueryViewOfType(OfTypeQVCacheKey extent, out GeneratedView generatedView); internal class ViewDictionary { readonly TryGetUserDefinedQueryView TryGetUserDefinedQueryView; readonly TryGetUserDefinedQueryViewOfType TryGetUserDefinedQueryViewOfType; private StorageMappingItemCollection m_storageMappingItemCollection; private static ConfigViewGenerator m_config = new ConfigViewGenerator(); // List of assemblies from which we have loaded views from private List m_knownViewGenAssemblies = new List(); // Indicates whether the views are being fetched from a generated class or they are being generated at the runtime private bool m_generatedViewsMode = true; /// /// Caches computation of view generation per . Cached value contains both query and update views. /// private readonly Memoizer> m_generatedViewsMemoizer; /// /// Caches computation of getting Type-specific Query Views - either by view gen or user-defined input. /// private readonly Memoizer m_generatedViewOfTypeMemoizer; internal ViewDictionary(StorageMappingItemCollection storageMappingItemCollection, out Dictionary userDefinedQueryViewsDict, out Dictionary userDefinedQueryViewsOfTypeDict) { this.m_storageMappingItemCollection = storageMappingItemCollection; this.m_generatedViewsMemoizer = new Memoizer>(SerializedGetGeneratedViews, null); this.m_generatedViewOfTypeMemoizer = new Memoizer(SerializedGeneratedViewOfType, OfTypeQVCacheKey.PairComparer.Instance); userDefinedQueryViewsDict = new Dictionary(EqualityComparer.Default); userDefinedQueryViewsOfTypeDict = new Dictionary(OfTypeQVCacheKey.PairComparer.Instance); TryGetUserDefinedQueryView = userDefinedQueryViewsDict.TryGetValue; TryGetUserDefinedQueryViewOfType = userDefinedQueryViewsOfTypeDict.TryGetValue; } private Dictionary SerializedGetGeneratedViews(EntityContainer container) { Debug.Assert(container != null); // Note that extentMappingViews will contain both query and update views. Dictionary extentMappingViews; // Get the mapping that has the entity container mapped. StorageEntityContainerMapping entityContainerMap = MappingMetadataHelper.GetEntityContainerMap(m_storageMappingItemCollection, container); // We get here because memoizer didn't find an entry for the container. // It might happen that the entry with generated views already exists for the counterpart container, so check it first. EntityContainer counterpartContainer = container.DataSpace == DataSpace.CSpace ? entityContainerMap.StorageEntityContainer : entityContainerMap.EdmEntityContainer; if (m_generatedViewsMemoizer.TryGetValue(counterpartContainer, out extentMappingViews)) { return extentMappingViews; } extentMappingViews = new Dictionary(); if (!entityContainerMap.HasViews) { return extentMappingViews; } // If we are in generated views mode. if (m_generatedViewsMode) { if(ObjectItemCollection.ViewGenerationAssemblies!=null && ObjectItemCollection.ViewGenerationAssemblies.Count>0) { SerializedCollectViewsFromObjectCollection(this.m_storageMappingItemCollection.Workspace, extentMappingViews); } else { SerializedCollectViewsFromReferencedAssemblies(this.m_storageMappingItemCollection.Workspace, extentMappingViews); } } if (extentMappingViews.Count == 0) { // We should change the mode to runtime generation of views. this.m_generatedViewsMode = false; this.SerializedGenerateViews(entityContainerMap, extentMappingViews); } Debug.Assert(extentMappingViews.Count > 0, "view should be generated at this point"); return extentMappingViews; } /// /// Call the View Generator's Generate view method /// and collect the Views and store it in a local dictionary. /// /// /// private void SerializedGenerateViews(StorageEntityContainerMapping entityContainerMap, Dictionary resultDictionary) { //If there are no entity set maps, don't call the view generation process Debug.Assert(entityContainerMap.HasViews); ViewGenResults viewGenResults = ViewgenGatekeeper.GenerateViewsFromMapping(entityContainerMap, m_config); KeyToListMap extentMappingViews = viewGenResults.Views; if (viewGenResults.HasErrors) { // Can get the list of errors using viewGenResults.Errors throw new MappingException(Helper.CombineErrorMessage(viewGenResults.Errors)); } foreach (KeyValuePair> keyValuePair in extentMappingViews.KeyValuePairs) { //Multiple Views are returned for an extent but the first view //is the only one that we will use for now. In the future, //we might start using the other views which are per type within an extent. GeneratedView generatedView; //Add the view to the local dictionary if (!resultDictionary.TryGetValue(keyValuePair.Key, out generatedView)) { generatedView = keyValuePair.Value[0]; resultDictionary.Add(keyValuePair.Key, generatedView); } } } /// /// Generates a single query view for a given Extent and type. It is used to generate OfType and OfTypeOnly views. /// /// Whether the view should include extents that are subtypes of the given entity private bool TryGenerateQueryViewOfType(EntityContainer entityContainer, EntitySetBase entity, EntityTypeBase type, bool includeSubtypes, out GeneratedView generatedView) { Debug.Assert(entityContainer != null); Debug.Assert(entity != null); Debug.Assert(type != null); if (type.Abstract) { generatedView = null; return false; } //Get the mapping that has the entity container mapped. StorageEntityContainerMapping entityContainerMap = MappingMetadataHelper.GetEntityContainerMap(m_storageMappingItemCollection, entityContainer); Debug.Assert(!entityContainerMap.IsEmpty, "There are no entity set maps"); bool success; ViewGenResults viewGenResults = ViewgenGatekeeper.GenerateTypeSpecificQueryView(entityContainerMap, m_config, entity, type, includeSubtypes, out success); if (!success) { generatedView = null; return false; //could not generate view } KeyToListMap extentMappingViews = viewGenResults.Views; if (viewGenResults.HasErrors) { throw new MappingException(Helper.CombineErrorMessage(viewGenResults.Errors)); } Debug.Assert(extentMappingViews.AllValues.Count() == 1, "Viewgen should have produced only one view"); generatedView = extentMappingViews.AllValues.First(); return true; } /// /// Tries to generate the Oftype or OfTypeOnly query view for a given entity set and type. /// Returns false if the view could not be generated. /// Possible reasons for failing are /// 1) Passing in OfTypeOnly on an abstract type /// 2) In user-specified query views mode a query for the given type is absent /// internal bool TryGetGeneratedViewOfType(MetadataWorkspace workspace, EntitySetBase entity, EntityTypeBase type, bool includeSubtypes, out GeneratedView generatedView) { OfTypeQVCacheKey key = new OfTypeQVCacheKey(entity, new Pair(type, includeSubtypes)); generatedView = this.m_generatedViewOfTypeMemoizer.Evaluate(key); return (generatedView != null); } /// /// Note: Null return value implies QV was not generated. /// /// private GeneratedView SerializedGeneratedViewOfType(OfTypeQVCacheKey arg) { GeneratedView generatedView; //See if we have collected user-defined QueryView if(TryGetUserDefinedQueryViewOfType(arg, out generatedView)) { return generatedView; } //Now we have to generate the type-specific view EntitySetBase entity = arg.First; EntityTypeBase type = arg.Second.First; bool includeSubtypes = arg.Second.Second; if (!TryGenerateQueryViewOfType(entity.EntityContainer, entity, type, includeSubtypes, out generatedView)) { generatedView = null; } return generatedView; } /// /// Returns the update or query view for an Extent as a /// string. /// There are a series of steps that we go through for discovering a view for an extent. /// To start with we assume that we are working with Generated Views. To find out the /// generated view we go to the ObjectItemCollection and see if it is not-null. If the ObjectItemCollection /// is non-null, we get the view generation assemblies that it might have cached during the /// Object metadata discovery.If there are no view generation assemblies we switch to the /// runtime view generation strategy. If there are view generation assemblies, we get the list and /// go through them and see if there are any assemblies that are there from which we have not already loaded /// the views. We collect the views from assemblies that we have not already collected from earlier. /// If the ObjectItemCollection is null and we are in the view generation mode, that means that /// the query or update is issued from the Value layer and this is the first time view has been asked for. /// The compile time view gen for value layer queries will work for very simple scenarios. /// If the users wants to get the performance benefit, they should call MetadataWorkspace.LoadFromAssembly. /// At this point we go through the referenced assemblies of the entry assembly( this wont work for Asp.net /// or if the viewgen assembly was not referenced by the executing application). /// and try to see if there were any view gen assemblies. If there are, we collect the views for all extents. /// Once we have all the generated views gathered, we try to get the view for the extent passed in. /// If we find one we will return it. If we can't find one an exception will be thrown. /// If there were no view gen assemblies either in the ObjectItemCollection or in the list of referenced /// assemblies of calling assembly, we change the mode to runtime view generation and will continue to /// be in that mode for the rest of the lifetime of the mapping item collection. /// internal GeneratedView GetGeneratedView(EntitySetBase extent, MetadataWorkspace workspace, StorageMappingItemCollection storageMappingItemCollection) { //First check if we have collected a view from user-defined query views //Dont need to worry whether to generate Query view or update viw, because that is relative to the extent. GeneratedView view; if (TryGetUserDefinedQueryView(extent, out view)) { return view; } //If this is a foreign key association, manufacture a view on the fly. if (extent.BuiltInTypeKind == BuiltInTypeKind.AssociationSet) { AssociationSet aSet = (AssociationSet)extent; if (aSet.ElementType.IsForeignKey) { if (m_config.IsViewTracing) { Helpers.StringTraceLine(String.Empty); Helpers.StringTraceLine(String.Empty); Helpers.FormatTraceLine("================= Generating FK Query View for: {0} =================", aSet.Name); Helpers.StringTraceLine(String.Empty); Helpers.StringTraceLine(String.Empty); } // Although we expose a collection of constraints in the API, there is only ever one constraint. Debug.Assert(aSet.ElementType.ReferentialConstraints.Count == 1, "aSet.ElementType.ReferentialConstraints.Count == 1"); ReferentialConstraint rc = aSet.ElementType.ReferentialConstraints.Single(); EntitySet dependentSet = aSet.AssociationSetEnds[rc.ToRole.Name].EntitySet; EntitySet principalSet = aSet.AssociationSetEnds[rc.FromRole.Name].EntitySet; DbExpression qView = dependentSet.Scan(); // Introduce an OfType view if the dependent end is a subtype of the entity set EntityType dependentType = MetadataHelper.GetEntityTypeForEnd((AssociationEndMember)rc.ToRole); EntityType principalType = MetadataHelper.GetEntityTypeForEnd((AssociationEndMember)rc.FromRole); if (dependentSet.ElementType.IsBaseTypeOf(dependentType)) { qView = qView.OfType(TypeUsage.Create(dependentType)); } if (rc.FromRole.RelationshipMultiplicity == RelationshipMultiplicity.ZeroOrOne) { // Filter out instances with existing relationships. qView = qView.Where(e => { DbExpression filter = null; foreach (EdmProperty fkProp in rc.ToProperties) { DbExpression notIsNull = e.Property(fkProp).IsNull().Not(); filter = null == filter ? notIsNull : filter.And(notIsNull); } return filter; }); } qView = qView.Select(e => { List ends = new List(); foreach (AssociationEndMember end in aSet.ElementType.AssociationEndMembers) { if (end.Name == rc.ToRole.Name) { var keyValues = new List>(); foreach (EdmMember keyMember in dependentSet.ElementType.KeyMembers) { keyValues.Add(e.Property((EdmProperty)keyMember)); } ends.Add(dependentSet.RefFromKey(DbExpressionBuilder.NewRow(keyValues), dependentType)); } else { // Manufacture a key using key values. var keyValues = new List>(); foreach (EdmMember keyMember in principalSet.ElementType.KeyMembers) { int offset = rc.FromProperties.IndexOf((EdmProperty)keyMember); keyValues.Add(e.Property(rc.ToProperties[offset])); } ends.Add(principalSet.RefFromKey(DbExpressionBuilder.NewRow(keyValues), principalType)); } } return TypeUsage.Create(aSet.ElementType).New(ends); }); return GeneratedView.CreateGeneratedViewForFKAssociationSet(aSet, aSet.ElementType, new DbQueryCommandTree(workspace, DataSpace.SSpace, qView), storageMappingItemCollection, m_config); } } // If no User-defined QV is found, call memoized View Generation procedure. Dictionary generatedViews = m_generatedViewsMemoizer.Evaluate(extent.EntityContainer); if (!generatedViews.TryGetValue(extent, out view)) { throw EntityUtil.InvalidOperation(System.Data.Entity.Strings.Mapping_Views_For_Extent_Not_Generated( (extent.EntityContainer.DataSpace==DataSpace.SSpace)?"Table":"EntitySet",extent.Name)); } return view; } /// /// Collect the views from object collection's view gen assembly /// /// /// private void SerializedCollectViewsFromObjectCollection(MetadataWorkspace workspace, Dictionary extentMappingViews) { IList allViewGenAssemblies = ObjectItemCollection.ViewGenerationAssemblies; if (allViewGenAssemblies != null) { foreach (Assembly assembly in allViewGenAssemblies) { object[] viewGenAttributes = assembly.GetCustomAttributes(typeof(System.Data.Mapping.EntityViewGenerationAttribute), false /*inherit*/); if ((viewGenAttributes != null) && (viewGenAttributes.Length != 0)) { foreach (EntityViewGenerationAttribute viewGenAttribute in viewGenAttributes) { Type viewContainerType = viewGenAttribute.ViewGenerationType; if (!viewContainerType.IsSubclassOf(typeof(EntityViewContainer))) { throw EntityUtil.InvalidOperation(System.Data.Entity.Strings.Generated_View_Type_Super_Class(StorageMslConstructs.EntityViewGenerationTypeName)); } EntityViewContainer viewContainer = (Activator.CreateInstance(viewContainerType) as EntityViewContainer); Debug.Assert(viewContainer != null, "Should be able to create the type"); SerializedAddGeneratedViewsInEntityViewContainer(workspace, viewContainer, extentMappingViews); } } } } } /// /// this method do the following check on the generated views in the EntityViewContainer, /// then add those views all at once to the dictionary /// 1. there should be one storeageEntityContainerMapping that has the same h /// C side and S side names as the EnittyViewcontainer /// 2. Generate the hash for the storageEntityContainerMapping in the MM closure, /// and this hash should be the same in EntityViewContainer /// 3. Generate the hash for all of the view text in the EntityViewContainer and /// this hash should be the same as the stored on in the EntityViewContainer /// /// private void SerializedAddGeneratedViewsInEntityViewContainer(MetadataWorkspace workspace, EntityViewContainer entityViewContainer, Dictionary extentMappingViews) { StorageEntityContainerMapping storageEntityContainerMapping; // first check if (!this.TryGetCorrespondingStorageEntityContainerMapping(entityViewContainer, workspace.GetItemCollection(DataSpace.CSSpace).GetItems(), out storageEntityContainerMapping)) { return; } // second check if (!this.SerializedVerifyHashOverMmClosure(storageEntityContainerMapping, entityViewContainer)) { throw new MappingException(Strings.ViewGen_HashOnMappingClosure_Not_Matching(entityViewContainer.EdmEntityContainerName)); } // third check, prior to the check, we collect all the views in the entity view container to the dictionary // if the views are changed then we will throw exception out if (this.VerifyViewsHaveNotChanged(workspace, entityViewContainer)) { this.SerializedAddGeneratedViews(workspace, entityViewContainer, extentMappingViews); } else { throw new InvalidOperationException(System.Data.Entity.Strings.Generated_Views_Changed); } } private bool TryGetCorrespondingStorageEntityContainerMapping(EntityViewContainer viewContainer, IEnumerable storageEntityContainerMappingList, out StorageEntityContainerMapping storageEntityContainerMapping) { storageEntityContainerMapping = null; foreach (var entityContainerMapping in storageEntityContainerMappingList) { // first check if (entityContainerMapping.EdmEntityContainer.Name == viewContainer.EdmEntityContainerName && entityContainerMapping.StorageEntityContainer.Name == viewContainer.StoreEntityContainerName) { storageEntityContainerMapping = entityContainerMapping; return true; } } return false; } private bool SerializedVerifyHashOverMmClosure(StorageEntityContainerMapping entityContainerMapping, EntityViewContainer entityViewContainer) { if (MetadataMappingHasherVisitor.GetMappingClosureHash(m_storageMappingItemCollection.MappingVersion, entityContainerMapping) == entityViewContainer.HashOverMappingClosure) { return true; } return false; } private bool VerifyViewsHaveNotChanged(MetadataWorkspace workspace, EntityViewContainer viewContainer) { //Now check whether the hash of the generated views match the one //we stored in the code file during design //Produce the hash and add it to the code var mappingCollection = (workspace.GetItemCollection(DataSpace.CSSpace) as StorageMappingItemCollection); Debug.Assert(mappingCollection != null,"Must have Mapping Collection in the Metadataworkspace"); string viewHash = MetadataHelper.GenerateHashForAllExtentViewsContent(mappingCollection.MappingVersion, viewContainer.ExtentViews); string storedViewHash = viewContainer.HashOverAllExtentViews; if (viewHash != storedViewHash) { return false; } return true; } //Collect the names of the entitysetbases and the generated views from //the generated type into a string so that we can produce a hash over it. private void SerializedAddGeneratedViews(MetadataWorkspace workspace, EntityViewContainer viewContainer, Dictionary extentMappingViews) { foreach (KeyValuePair extentView in viewContainer.ExtentViews) { EntityContainer entityContainer = null; EntitySetBase extent = null; string extentFullName = extentView.Key; int extentNameIndex = extentFullName.LastIndexOf('.'); if (extentNameIndex != -1) { string entityContainerName = extentFullName.Substring(0, extentNameIndex); string extentName = extentFullName.Substring(extentFullName.LastIndexOf('.') + 1); if (!workspace.TryGetItem(entityContainerName, DataSpace.CSpace, out entityContainer)) { workspace.TryGetItem(entityContainerName, DataSpace.SSpace, out entityContainer); } if (entityContainer != null) { entityContainer.BaseEntitySets.TryGetValue(extentName, false, out extent); } } if (extent == null) { throw new MappingException(System.Data.Entity.Strings.Generated_Views_Invalid_Extent(extentFullName)); } //Create a Generated view and cache it GeneratedView generatedView; //Add the view to the local dictionary if (!extentMappingViews.TryGetValue(extent, out generatedView)) { generatedView = GeneratedView.CreateGeneratedView( extent, null, // edmType null, // commandTree extentView.Value, // eSQL m_storageMappingItemCollection, new ConfigViewGenerator()); extentMappingViews.Add(extent, generatedView); } } } /// /// Tries to collect the views from the referenced assemblies of Entry assembly. /// /// private void SerializedCollectViewsFromReferencedAssemblies(MetadataWorkspace workspace, Dictionary extentMappingViews) { ObjectItemCollection objectCollection; ItemCollection itemCollection; if (!workspace.TryGetItemCollection(DataSpace.OSpace, out itemCollection)) { //Possible enhancement : Think about achieving the same thing without creating Object Item Collection. objectCollection = new ObjectItemCollection(); itemCollection = objectCollection; // The GetEntryAssembly method can return a null reference //when a managed assembly has been loaded from an unmanaged application. Assembly entryAssembly = Assembly.GetEntryAssembly(); if (entryAssembly != null) { objectCollection.ImplicitLoadViewsFromAllReferencedAssemblies(entryAssembly); } } this.SerializedCollectViewsFromObjectCollection(workspace, extentMappingViews); } } } }