CellTreeNode.cs source code in C# .NET

Source code for the .NET framework in C#

                        

Code:

/ 4.0 / 4.0 / untmp / DEVDIV_TFS / Dev10 / Releases / RTMRel / ndp / fx / src / DataEntity / System / Data / Map / ViewGeneration / Structures / CellTreeNode.cs / 1305376 / CellTreeNode.cs

                            //---------------------------------------------------------------------- 
// 
//      Copyright (c) Microsoft Corporation.  All rights reserved.
// 
// 
// @owner [....]
// @backupOwner [....] 
//--------------------------------------------------------------------- 

using System.Data.Common.Utils; 
using System.Data.Common.Utils.Boolean;
using System.Collections.Generic;
using System.Text;
using System.Data.Mapping.ViewGeneration.CqlGeneration; 
using System.Data.Mapping.ViewGeneration.QueryRewriting;
using System.Data.Mapping.ViewGeneration.Utils; 
using System.Linq; 

namespace System.Data.Mapping.ViewGeneration.Structures 
{

    using WrapperBoolExpr = BoolExpr;
    using System.Data.Entity; 

    // This class represents a node in the update or query mapping view tree 
    // (of course, the root node represents the full view) 
    // Each node represents an expression of the form:
    // SELECT  FROM  WHERE  
    // The WHERE clause is of the form X1 OR X2 OR ... where each Xi is a multiconstant
    internal abstract partial class CellTreeNode : InternalBase
    {
 
        #region Constructor
        // effects: Creates a cell tree node with a reference to projectedSlotMap for 
        // deciphering the fields in this 
        protected CellTreeNode(ViewgenContext context)
        { 
            m_viewgenContext = context;
        }

        // effects: returns a copy of the tree below node 
        internal CellTreeNode MakeCopy()
        { 
            DefaultCellTreeVisitor visitor = new DefaultCellTreeVisitor(); 
            CellTreeNode result = Accept(visitor, true);
            return result; 
        }
        #endregion

        #region Fields 
        private ViewgenContext m_viewgenContext;
        #endregion 
 
        #region Properties
        // effects: Returns the operation being performed by this node 
        internal abstract CellTreeOpType OpType { get; }

        // effects: Returns the right domain map associated with this celltreenode
        internal abstract MemberDomainMap RightDomainMap { get; } 

        internal abstract FragmentQuery LeftFragmentQuery { get; } 
 
        internal abstract FragmentQuery RightFragmentQuery { get; }
 
        internal bool IsEmptyRightFragmentQuery
        {
            get { return !m_viewgenContext.RightFragmentQP.IsSatisfiable(RightFragmentQuery); }
        } 

        // effects: Returns the attributes available/projected from this node 
        internal abstract Set Attributes { get; } 

        // effects: Returns the children of this node 
        internal abstract List Children { get; }

        // effects: Returns the number of slots projected from this node
        internal abstract int NumProjectedSlots { get; } 

        // effects: Returns the number of boolean slots in this node 
        internal abstract int NumBoolSlots { get; } 

        internal MemberProjectionIndex ProjectedSlotMap 
        {
            get { return m_viewgenContext.MemberMaps.ProjectedSlotMap; }
        }
 
        internal ViewgenContext ViewgenContext
        { 
            get { return m_viewgenContext; } 
        }
 
        #endregion

        #region Abstract Methods
        // effects: Given a leaf cell node and the slots required by the parent, returns 
        // a CqlBlock corresponding to the tree rooted at this
        internal abstract CqlBlock ToCqlBlock(bool[] requiredSlots, CqlIdentifiers identifiers, ref int blockAliasNum, 
            ref List withStatements); 

        // Effects: Returns true if slot at slot number "slot" is projected 
        // by some node in tree rooted at this
        internal abstract bool IsProjectedSlot(int slot);

        // Standard accept method for visitor pattern. TOutput is the return 
        // type for visitor methods.
        internal abstract TOutput Accept(CellTreeVisitor visitor, TInput param); 
        internal abstract TOutput Accept(SimpleCellTreeVisitor visitor, TInput param); 
        #endregion
 
        #region Visitor methods
        // effects: Given a cell tree node , removes unnecessary
        // "nesting" that occurs in the tree -- an unnecessary nesting
        // occurs when a node has exactly one child. 
        internal CellTreeNode Flatten()
        { 
            return FlatteningVisitor.Flatten(this); 
        }
 
        // effects: Gets all the leaves in this
        internal List GetLeaves()
        {
            return GetLeafNodes().Select(leafNode => leafNode.LeftCellWrapper).ToList(); 
        }
 
        // effects: Gets all the leaves in this 
        internal IEnumerable GetLeafNodes()
        { 
            return LeafVisitor.GetLeaves(this);
        }

        // effects: Like Flatten, flattens the tree and then collapses 
        // associative operators, e.g., (A IJ B) IJ C is changed to A IJ B IJ C
        internal CellTreeNode AssociativeFlatten() 
        { 
            return AssociativeOpFlatteningVisitor.Flatten(this);
        } 

        #endregion

        #region Helper methods, e.g., for slots and strings 
        // effects: Returns true iff the Op (e.g., IJ) is associative, i.e.,
        // A OP (B OP C) is the same as (A OP B) OP C or A OP B OP C 
        internal static bool IsAssociativeOp(CellTreeOpType opType) 
        {
            // This is not true for LOJ and LASJ 
            return opType == CellTreeOpType.IJ || opType == CellTreeOpType.Union ||
                opType == CellTreeOpType.FOJ;
        }
 
        // effects: Returns an array of booleans where bool[i] is set to true
        // iff some node in the tree rooted at node projects that slot 
        internal bool[] GetProjectedSlots() 
        {
            // Gets the information on the normal and the boolean slots 
            int totalSlots = ProjectedSlotMap.Count + NumBoolSlots;
            bool[] slots = new bool[totalSlots];
            for (int i = 0; i < totalSlots; i++)
            { 
                slots[i] = IsProjectedSlot(i);
            } 
            return slots; 
        }
 
        // effects: Given a slot number, slotNum, returns the output member path
        // that this slot contributes/corresponds to in the extent view. If
        // the slot corresponds to one of the boolean variables, returns null
        protected MemberPath GetMemberPath(int slotNum) 
        {
            return ProjectedSlot.GetMemberPath(slotNum, ProjectedSlotMap, NumBoolSlots); 
        } 

        // effects: Given the index of a boolean variable (e.g., of from1), 
        // returns the slot number for that boolean in this
        protected int BoolIndexToSlot(int boolIndex)
        {
            // Booleans appear after the regular slot 
            return ProjectedSlot.BoolIndexToSlot(boolIndex, ProjectedSlotMap, NumBoolSlots);
        } 
 
        // effects: Given a slotNum corresponding to a boolean slot, returns
        // the cel number that the cell corresponds to 
        protected int SlotToBoolIndex(int slotNum)
        {
            return ProjectedSlot.SlotToBoolIndex(slotNum, ProjectedSlotMap, NumBoolSlots);
        } 

        // effects: Returns true if slotNum corresponds to a key slot in the 
        // output extent view 
        protected bool IsKeySlot(int slotNum)
        { 
            return ProjectedSlot.IsKeySlot(slotNum, ProjectedSlotMap, NumBoolSlots);
        }

        // effects: Returns true if slotNum corresponds to a bool slot and 
        // not a regular field
        protected bool IsBoolSlot(int slotNum) 
        { 
            return ProjectedSlot.IsBoolSlot(slotNum, ProjectedSlotMap, NumBoolSlots);
        } 


        // effects: Returns the slot numbers corresponding to the key fields
        // in the m_projectedSlotMap 
        protected IEnumerable KeySlots
        { 
            get 
            {
                int numMembers = ProjectedSlotMap.Count; 
                for (int slotNum = 0; slotNum < numMembers; slotNum++)
                {
                    if (true == IsKeySlot(slotNum))
                    { 
                        yield return slotNum;
                    } 
                } 
            }
        } 

        // effects: Modifies builder to contain a Cql query corresponding to
        // the tree rooted at this
        internal override void ToFullString(StringBuilder builder) 
        {
            int blockAliasNum = 0; 
            // Get the required slots, get the block and then get the string 
            bool[] requiredSlots = GetProjectedSlots();
            // Using empty identifiers over here since we do not use this for the actual CqlGeneration 
            CqlIdentifiers identifiers = new CqlIdentifiers();
            List withStatements = new List();
            CqlBlock block = ToCqlBlock(requiredSlots, identifiers, ref blockAliasNum, ref withStatements);
            block.AsCql(builder, false, 1); 
        }
        #endregion 
    } 
}

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


                        

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