Imported Upstream version 4.6.0.125

Former-commit-id: a2155e9bd80020e49e72e86c44da02a8ac0e57a4

mcs/class/referencesource/System.Data.Entity/System/Data/SqlClient/SqlSpatialDataReader.cs

@@ -0,0 +1,107 @@
+//------------------------------------------------------------------------------
+// <copyright file="SqlSpatialDataReader.cs" company="Microsoft">
+//      Copyright (c) Microsoft Corporation.  All rights reserved.
+// </copyright>
+//
+// @owner  willa
+// @backupOwner [....]
+//------------------------------------------------------------------------------
+
+using System.Data.Common.Utils;
+using System.Data.Entity;
+using System.Data.Spatial;
+using System.Data.SqlTypes;
+using System.Diagnostics;
+using System.IO;
+using System.Linq.Expressions;
+using System.Reflection;
+
+namespace System.Data.SqlClient
+{
+    /// <summary>
+    /// SqlClient specific implementation of <see cref="DbSpatialDataReader"/>
+    /// </summary>
+    internal sealed partial class SqlSpatialDataReader : DbSpatialDataReader
+    {
+        private readonly SqlDataReader reader;
+        private const string geometrySqlType = "sys.geometry";
+        private const string geographySqlType = "sys.geography";
+
+        internal SqlSpatialDataReader(SqlDataReader underlyingReader)
+        {
+            this.reader = underlyingReader;
+        }
+
+        public override DbGeography GetGeography(int ordinal)
+        {
+            EnsureGeographyColumn(ordinal);
+            SqlBytes geogBytes = this.reader.GetSqlBytes(ordinal);
+            object providerValue = sqlGeographyFromBinaryReader.Value(new BinaryReader(geogBytes.Stream));
+            return SqlSpatialServices.Instance.GeographyFromProviderValue(providerValue);
+        }
+
+        public override DbGeometry GetGeometry(int ordinal)
+        {
+            EnsureGeometryColumn(ordinal);
+ 	        SqlBytes geomBytes = this.reader.GetSqlBytes(ordinal);
+            object providerValue = sqlGeometryFromBinaryReader.Value(new BinaryReader(geomBytes.Stream));
+            return SqlSpatialServices.Instance.GeometryFromProviderValue(providerValue);
+        }
+
+        private static readonly Singleton<Func<BinaryReader, object>> sqlGeographyFromBinaryReader = new Singleton<Func<BinaryReader, object>>(() => CreateBinaryReadDelegate(SqlProviderServices.GetSqlTypesAssembly().SqlGeographyType));
+        private static readonly Singleton<Func<BinaryReader, object>> sqlGeometryFromBinaryReader = new Singleton<Func<BinaryReader, object>>(() => CreateBinaryReadDelegate(SqlProviderServices.GetSqlTypesAssembly().SqlGeometryType));
+
+        // test to ensure that the SQL column has the expected SQL type.   Don't use the CLR type to avoid having to worry about differences in 
+        // type versions between the client and the database.  
+        private void EnsureGeographyColumn(int ordinal)
+        {
+            string fieldTypeName = this.reader.GetDataTypeName(ordinal);
+            if (!fieldTypeName.EndsWith(geographySqlType, StringComparison.Ordinal)) // Use EndsWith so that we just see the schema and type name, not the database name.
+            {
+                throw new InvalidDataException(Strings.SqlProvider_InvalidGeographyColumn(fieldTypeName));
+            }
+        }
+
+        private void EnsureGeometryColumn(int ordinal)
+        {
+            string fieldTypeName = this.reader.GetDataTypeName(ordinal);
+            if (!fieldTypeName.EndsWith(geometrySqlType, StringComparison.Ordinal)) // Use EndsWith so that we just see the schema and type name, not the database name.
+            {
+                throw new InvalidDataException(Strings.SqlProvider_InvalidGeometryColumn(fieldTypeName));
+            }
+        }
+
+        /// <summary>
+        /// Builds and compiles the Expression equivalent of the following:
+        ///   
+        /// (BinaryReader r) => { var result = new SpatialType(); result.Read(r); return r; }
+        ///   
+        /// The construct/read pattern is preferred over casting the result of calling GetValue on the DataReader,
+        /// because constructing the value directly allows client code to specify the type, rather than SqlClient using
+        /// the server-specified assembly qualified type name from TDS to try to locate the correct type on the client.
+        /// </summary>
+        /// <param name="spatialType"></param>
+        /// <returns></returns>
+        private static Func<BinaryReader, object> CreateBinaryReadDelegate(Type spatialType)
+        {
+            Debug.Assert(spatialType != null, "Ensure spatialType is non-null before calling CreateBinaryReadDelegate");
+
+            var readerParam = Expression.Parameter(typeof(BinaryReader));
+            var binarySerializable = Expression.Variable(spatialType);
+            var readMethod = spatialType.GetMethod("Read", BindingFlags.Public | BindingFlags.Instance, null, new[] { typeof(System.IO.BinaryReader) }, null);
+
+            var ex = Expression.Lambda<Func<BinaryReader, object>>(
+                            Expression.Block(
+                                new[] { binarySerializable },
+                                Expression.Assign(binarySerializable, Expression.New(spatialType)),
+                                Expression.Call(binarySerializable, readMethod, readerParam),
+                                binarySerializable
+                            ),
+                            readerParam
+                        );
+
+            Func<BinaryReader, object> result = ex.Compile();
+            return result;
+        }
+    }
+}