Imported Upstream version 4.6.0.125

Former-commit-id: a2155e9bd80020e49e72e86c44da02a8ac0e57a4

mcs/class/referencesource/System.Data.Entity/System/Data/Metadata/MappingMetadataHelper.cs

@@ -0,0 +1,110 @@
+//---------------------------------------------------------------------
+// <copyright file="MappingMetadataHelper.cs" company="Microsoft">
+//      Copyright (c) Microsoft Corporation.  All rights reserved.
+// </copyright>
+//
+// @owner       [....]
+// @backupOwner [....]
+//---------------------------------------------------------------------
+namespace System.Data.Metadata.Edm
+{
+    using System.Collections.Generic;
+    using System.Collections.ObjectModel;
+    using System.Data.Common.Utils;
+    using System.Data.Mapping;
+    using System.Diagnostics;
+    using System.Linq;
+
+    /// <summary>
+    /// Helps answer mapping questions since we don't have a good API for mapping information
+    /// </summary>
+    internal static class MappingMetadataHelper
+    {
+
+        internal static IEnumerable<StorageTypeMapping> GetMappingsForEntitySetAndType(StorageMappingItemCollection mappingCollection, EntityContainer container, EntitySetBase entitySet, EntityTypeBase entityType)
+        {
+            Debug.Assert(entityType != null, "EntityType parameter should not be null.");
+            StorageEntityContainerMapping containerMapping = GetEntityContainerMap(mappingCollection, container);
+            StorageSetMapping extentMap = containerMapping.GetSetMapping(entitySet.Name);
+
+            //The Set may have no mapping
+            if (extentMap != null)
+            {
+                //for each mapping fragment of Type we are interested in within the given set
+                //Check use of IsOfTypes in Code review
+                foreach (StorageTypeMapping typeMap in extentMap.TypeMappings.Where(map => map.Types.Union(map.IsOfTypes).Contains(entityType)))
+                {
+                    yield return typeMap;
+                }
+            }
+        }
+
+       /// <summary>
+       /// Returns all mapping fragments for the given entity set's types and their parent types.
+       /// </summary>
+        internal static IEnumerable<StorageTypeMapping> GetMappingsForEntitySetAndSuperTypes(StorageMappingItemCollection mappingCollection, EntityContainer container, EntitySetBase entitySet, EntityTypeBase childEntityType)
+        {
+            return MetadataHelper.GetTypeAndParentTypesOf(childEntityType, mappingCollection.EdmItemCollection, true /*includeAbstractTypes*/).SelectMany(
+                edmType => 
+                    edmType.EdmEquals(childEntityType) ? 
+                      GetMappingsForEntitySetAndType(mappingCollection, container, entitySet, (edmType as EntityTypeBase))
+                    : GetIsTypeOfMappingsForEntitySetAndType(mappingCollection, container, entitySet, (edmType as EntityTypeBase), childEntityType)
+                ).ToList();
+        }
+
+        /// <summary>
+        /// Returns mappings for the given set/type only if the mapping applies also to childEntittyType either via IsTypeOf or explicitly specifying multiple types in mapping fragments.
+        /// </summary>
+        private static IEnumerable<StorageTypeMapping> GetIsTypeOfMappingsForEntitySetAndType(StorageMappingItemCollection mappingCollection, EntityContainer container, EntitySetBase entitySet, EntityTypeBase entityType, EntityTypeBase childEntityType)
+        {
+            foreach (var mapping in GetMappingsForEntitySetAndType(mappingCollection, container, entitySet, entityType))
+            {
+                if (mapping.IsOfTypes.Any(parentType => parentType.IsAssignableFrom(childEntityType)) || mapping.Types.Contains(childEntityType))
+                {
+                    yield return mapping;
+                }
+            }
+        }      
+
+        internal static IEnumerable<StorageEntityTypeModificationFunctionMapping> GetModificationFunctionMappingsForEntitySetAndType(StorageMappingItemCollection mappingCollection, EntityContainer container, EntitySetBase entitySet, EntityTypeBase entityType)
+        {
+            StorageEntityContainerMapping containerMapping = GetEntityContainerMap(mappingCollection, container);
+
+            StorageSetMapping extentMap = containerMapping.GetSetMapping(entitySet.Name);
+            StorageEntitySetMapping entitySetMapping = extentMap as StorageEntitySetMapping;
+
+            //The Set may have no mapping
+            if (entitySetMapping != null)
+            {
+                if (entitySetMapping != null) //could be association set mapping
+                {
+                    foreach (var v in entitySetMapping.ModificationFunctionMappings.Where(functionMap => functionMap.EntityType.Equals(entityType)))
+                    {
+                        yield return v;
+                    }
+                }
+            }
+
+        }
+
+        internal static StorageEntityContainerMapping GetEntityContainerMap(StorageMappingItemCollection mappingCollection, EntityContainer entityContainer)
+        {
+            ReadOnlyCollection<StorageEntityContainerMapping> entityContainerMaps = mappingCollection.GetItems<StorageEntityContainerMapping>();
+            StorageEntityContainerMapping entityContainerMap = null;
+            foreach (StorageEntityContainerMapping map in entityContainerMaps)
+            {
+                if ((entityContainer.Equals(map.EdmEntityContainer))
+                    || (entityContainer.Equals(map.StorageEntityContainer)))
+                {
+                    entityContainerMap = map;
+                    break;
+                }
+            }
+            if (entityContainerMap == null)
+            {
+                throw new MappingException(System.Data.Entity.Strings.Mapping_NotFound_EntityContainer(entityContainer.Name));
+            }
+            return entityContainerMap;
+        }
+    }
+}