PlanCompilerUtil.cs source code in C# .NET

Source code for the .NET framework in C#

                        
Code:

                         / Net / Net / 3.5.50727.3053 / DEVDIV / depot / DevDiv / releases / Orcas / SP / ndp / fx / src / DataEntity / System / Data / Query / PlanCompiler / PlanCompilerUtil.cs / 1 / PlanCompilerUtil.cs
                        

                        
                            //---------------------------------------------------------------------- 
// 
//      Copyright (c) Microsoft Corporation.  All rights reserved.
// 
// 
// @owner  [....], [....]
//--------------------------------------------------------------------- 
 
using System;
using md = System.Data.Metadata.Edm; 
using System.Data.Query.InternalTrees;

namespace System.Data.Query.PlanCompiler
{ 
    /// 
    /// Utility class for the methods shared among the plan compiler components 
    ///  
    internal static class PlanCompilerUtil
    { 
        /// 
        /// Utility method that determines whether a given CaseOp subtree can be optimized.
        /// Called by both PreProcessor and NominalTypeEliminator.
        /// 
        /// If the case statement is of the shape:
        ///     case when X then NULL else Y, or 
        ///     case when X then Y else NULL, 
        /// where Y is of row type, and the types of the input CaseOp, the NULL and Y are the same,
        /// return true 
        /// 
        /// 
        /// 
        ///  
        internal static bool IsRowTypeCaseOpWithNullability(CaseOp op, Node n, out bool thenClauseIsNull)
        { 
            thenClauseIsNull = false;  //any default value will do 

            if (!md.TypeSemantics.IsRowType(op.Type)) 
            {
                return false;
            }
            if (n.Children.Count != 3) 
            {
                return false; 
            } 

            //All three types must be equal 
            if (!n.Child1.Op.Type.EdmEquals(op.Type) || !n.Child2.Op.Type.EdmEquals(op.Type))
            {
                return false;
            } 

            //At least one of Child1 and Child2 needs to be a null 
            if (n.Child1.Op.OpType == OpType.Null) 
            {
                thenClauseIsNull = true; 
                return true;
            }
            if (n.Child2.Op.OpType == OpType.Null)
            { 
                // thenClauseIsNull stays false
                return true; 
            } 

            return false; 
        }
    }
}

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
//---------------------------------------------------------------------- 
// 
//      Copyright (c) Microsoft Corporation.  All rights reserved.
// 
// 
// @owner  [....], [....]
//--------------------------------------------------------------------- 
 
using System;
using md = System.Data.Metadata.Edm; 
using System.Data.Query.InternalTrees;

namespace System.Data.Query.PlanCompiler
{ 
    /// 
    /// Utility class for the methods shared among the plan compiler components 
    ///  
    internal static class PlanCompilerUtil
    { 
        /// 
        /// Utility method that determines whether a given CaseOp subtree can be optimized.
        /// Called by both PreProcessor and NominalTypeEliminator.
        /// 
        /// If the case statement is of the shape:
        ///     case when X then NULL else Y, or 
        ///     case when X then Y else NULL, 
        /// where Y is of row type, and the types of the input CaseOp, the NULL and Y are the same,
        /// return true 
        /// 
        /// 
        /// 
        ///  
        internal static bool IsRowTypeCaseOpWithNullability(CaseOp op, Node n, out bool thenClauseIsNull)
        { 
            thenClauseIsNull = false;  //any default value will do 

            if (!md.TypeSemantics.IsRowType(op.Type)) 
            {
                return false;
            }
            if (n.Children.Count != 3) 
            {
                return false; 
            } 

            //All three types must be equal 
            if (!n.Child1.Op.Type.EdmEquals(op.Type) || !n.Child2.Op.Type.EdmEquals(op.Type))
            {
                return false;
            } 

            //At least one of Child1 and Child2 needs to be a null 
            if (n.Child1.Op.OpType == OpType.Null) 
            {
                thenClauseIsNull = true; 
                return true;
            }
            if (n.Child2.Op.OpType == OpType.Null)
            { 
                // thenClauseIsNull stays false
                return true; 
            } 

            return false; 
        }
    }
}

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

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