Validator.cs source code in C# .NET

                        Code:
                         / 4.0 / 4.0 / untmp / DEVDIV_TFS / Dev10 / Releases / RTMRel / ndp / fx / src / DataEntity / System / Data / Common / CommandTrees / Internal / Validator.cs / 1305376 / Validator.cs
                        
                        
                            //---------------------------------------------------------------------- 
// 
//      Copyright (c) Microsoft Corporation.  All rights reserved.
// 
// 
// @owner  [....]
// @backupOwner [....] 
//--------------------------------------------------------------------- 

using System; 
using System.Collections.Generic;
using System.Globalization;

using System.Data.Common; 
using System.Data.Metadata.Edm;
using System.Linq; 
using System.Diagnostics; 

namespace System.Data.Common.CommandTrees.Internal 
{
    internal sealed class DbExpressionValidator : DbExpressionRebinder
    {
        private readonly DataSpace requiredSpace; 
        private readonly DataSpace[] allowedMetadataSpaces;
        private readonly DataSpace[] allowedFunctionSpaces; 
        private readonly Dictionary paramMappings = new Dictionary(); 
        private readonly Stack> variableScopes = new Stack>();
 
        private string expressionArgumentName;

        internal DbExpressionValidator(MetadataWorkspace metadata, DataSpace expectedDataSpace)
            : base(metadata) 
        {
            this.requiredSpace = expectedDataSpace; 
            this.allowedFunctionSpaces = new[] { DataSpace.CSpace, DataSpace.SSpace }; 
            if (expectedDataSpace == DataSpace.SSpace)
            { 
                this.allowedMetadataSpaces = new[] { DataSpace.SSpace, DataSpace.CSpace };
            }
            else
            { 
                this.allowedMetadataSpaces = new[] { DataSpace.CSpace };
            } 
        } 

        internal Dictionary Parameters { get { return this.paramMappings; } } 

        internal void ValidateExpression(DbExpression expression, string argumentName)
        {
            Debug.Assert(expression != null, "Ensure expression is non-null before calling ValidateExpression"); 
            this.expressionArgumentName = argumentName;
            this.VisitExpression(expression); 
            this.expressionArgumentName = null; 
            Debug.Assert(this.variableScopes.Count == 0, "Variable scope stack left in inconsistent state");
        } 

        protected override EntitySetBase VisitEntitySet(EntitySetBase entitySet)
        {
            return ValidateMetadata(entitySet, base.VisitEntitySet, es => es.EntityContainer.DataSpace, this.allowedMetadataSpaces); 
        }
 
        protected override EdmFunction VisitFunction(EdmFunction function) 
        {
            // Functions from the current space and S-Space are allowed 
            return ValidateMetadata(function, base.VisitFunction, func => func.DataSpace, this.allowedFunctionSpaces);
        }

        protected override EdmType VisitType(EdmType type) 
        {
            return ValidateMetadata(type, base.VisitType, et => et.DataSpace, this.allowedMetadataSpaces); 
        } 

        protected override TypeUsage VisitTypeUsage(TypeUsage type) 
        {
            return ValidateMetadata(type, base.VisitTypeUsage, tu => tu.EdmType.DataSpace, this.allowedMetadataSpaces);
        }
 
        protected override void OnEnterScope(IEnumerable scopeVariables)
        { 
            var newScope = scopeVariables.ToDictionary(var => var.VariableName, var => var.ResultType, StringComparer.Ordinal); 
            this.variableScopes.Push(newScope);
        } 

        protected override void OnExitScope()
        {
            this.variableScopes.Pop(); 
        }
 
        public override DbExpression Visit(DbVariableReferenceExpression expression) 
        {
            DbExpression result = base.Visit(expression); 
            if(result.ExpressionKind == DbExpressionKind.VariableReference)
            {
                DbVariableReferenceExpression varRef = (DbVariableReferenceExpression)result;
                TypeUsage foundType = null; 
                foreach(Dictionary scope in this.variableScopes)
                { 
                    if(scope.TryGetValue(varRef.VariableName, out foundType)) 
                    {
                        break; 
                    }
                }

                if(foundType == null) 
                {
                    ThrowInvalid(System.Data.Entity.Strings.Cqt_Validator_VarRefInvalid(varRef.VariableName)); 
                } 

                // SQLBUDT#545720: Equivalence is not a sufficient check (consider row types) - equality is required. 
                if (!TypeSemantics.IsEqual(varRef.ResultType, foundType))
                {
                    ThrowInvalid(System.Data.Entity.Strings.Cqt_Validator_VarRefTypeMismatch(varRef.VariableName));
                } 
            }
 
            return result; 
        }
 
        public override DbExpression Visit(DbParameterReferenceExpression expression)
        {
            DbExpression result = base.Visit(expression);
            if (result.ExpressionKind == DbExpressionKind.ParameterReference) 
            {
                DbParameterReferenceExpression paramRef = result as DbParameterReferenceExpression; 
 
                DbParameterReferenceExpression foundParam;
                if (this.paramMappings.TryGetValue(paramRef.ParameterName, out foundParam)) 
                {
                    // SQLBUDT#545720: Equivalence is not a sufficient check (consider row types for TVPs) - equality is required.
                    if (!TypeSemantics.IsEqual(paramRef.ResultType, foundParam.ResultType))
                    { 
                        ThrowInvalid(Entity.Strings.Cqt_Validator_InvalidIncompatibleParameterReferences(paramRef.ParameterName));
                    } 
                } 
                else
                { 
                    this.paramMappings.Add(paramRef.ParameterName, paramRef);
                }
            }
            return result; 
        }
 
        private TMetadata ValidateMetadata(TMetadata metadata, Func map, Func getDataSpace, DataSpace[] allowedSpaces) 
        {
            TMetadata result = map(metadata); 
            if (!object.ReferenceEquals(metadata, result))
            {
                ThrowInvalidMetadata(metadata);
            } 

            DataSpace resultSpace = getDataSpace(result); 
            if (!allowedSpaces.Any(ds => ds == resultSpace)) 
            {
                ThrowInvalidSpace(metadata); 
            }
            return result;
        }
 
        private void ThrowInvalidMetadata(TMetadata invalid)
        { 
            ThrowInvalid(Entity.Strings.Cqt_Validator_InvalidOtherWorkspaceMetadata(typeof(TMetadata).Name)); 
        }
 
        private void ThrowInvalidSpace(TMetadata invalid)
        {
            ThrowInvalid(Entity.Strings.Cqt_Validator_InvalidIncorrectDataSpaceMetadata(typeof(TMetadata).Name, Enum.GetName(typeof(DataSpace), this.requiredSpace)));
        } 

        private void ThrowInvalid(string message) 
        { 
            throw EntityUtil.Argument(message, this.expressionArgumentName);
        } 
    }
}

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
Link Menu

Network programming in C#, Network Programming in VB.NET, Network Programming in .NET
This book is available now!
Buy at Amazon US or
Buy at Amazon UK
Validator.cs source code in C# .NET

Source code for the .NET framework in C#

Code:

Link Menu
