CellPartitioner.cs source code in C# .NET

Source code for the .NET framework in C#

                        
Code:

                         / Dotnetfx_Vista_SP2 / Dotnetfx_Vista_SP2 / 8.0.50727.4016 / DEVDIV / depot / DevDiv / releases / Orcas / QFE / ndp / fx / src / DataEntity / System / Data / Map / ViewGeneration / CellPartitioner.cs / 1 / CellPartitioner.cs
                        

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

 
using System.Data.Common.Utils;
using System.Data.Mapping.ViewGeneration.Structures;
using System.Collections.Generic;
using System.Data.Mapping.ViewGeneration.Validation; 
using System.Text;
using System.Data.Mapping.Update.Internal; 
using System.Collections.ObjectModel; 
using System.Data.Metadata.Edm;
 
namespace System.Data.Mapping.ViewGeneration {

    using CellGroup = Set;
 
    // This class is responsible for partitioning cells into groups of cells
    // that are related and for which view generation needs to be done together 
    internal class CellPartitioner : InternalBase { 

        #region Constructor 
        // effects: Creates a partitioner for cells with extra information
        // about foreign key constraints
        internal CellPartitioner(IEnumerable cells, IEnumerable foreignKeyConstraints) {
            m_foreignKeyConstraints = foreignKeyConstraints; 
            m_cells = cells;
        } 
        #endregion 

        #region Fields 
        private IEnumerable m_cells;
        private IEnumerable m_foreignKeyConstraints;
        #endregion
 
        #region Available Methods
        // effects: Given a list of cells, segments them into multiple 
        // "groups" such that view generation (including validation) of one 
        // group can be done independently of another group. Returns the
        // groups as a list (uses the foreign key information as well) 
        internal List GroupRelatedCells() {
            // If two cells share the same C or S, we place them in the same group
            // For each cell, determine the Cis and Sis that it refers
            // to. For every Ci (Si), keep track of the cells that Ci is 
            // contained in. At the end, run through the Cis and Sis and do a
            // "connected components" algorithm to determine partitions 
 
            // Now form a graph between different cells -- then compute the connected
            // components in it 
            UndirectedGraph graph = new UndirectedGraph(EqualityComparer.Default);

            List alreadyAddedCells = new List();
            // For each extent, add an edge between it and all previously 
            // added extents with which it overlaps
 
            foreach (Cell cell in m_cells) { 
                graph.AddVertex(cell);
                // Add an edge from this cell to the already added cells 
                EntitySetBase firstCExtent = cell.CQuery.Extent;
                EntitySetBase firstSExtent = cell.SQuery.Extent;
                foreach (Cell existingCell in alreadyAddedCells) {
                    EntitySetBase secondCExtent = existingCell.CQuery.Extent; 
                    EntitySetBase secondSExtent = existingCell.SQuery.Extent;
 
                    // Add an edge between cell and existingCell if 
                    // * They have the same C or S extent
                    // * They are linked via a foreign key between the S extents 
                    // * They are linked via a relationship
                    bool sameExtent = secondCExtent.Equals(firstCExtent) || secondSExtent.Equals(firstSExtent);
                    bool linkViaForeignKey = OverlapViaForeignKeys(cell, existingCell);
                    bool linkViaRelationship = AreCellsConnectedViaRelationship(cell, existingCell); 

                    if (sameExtent || linkViaForeignKey || linkViaRelationship) { 
                       graph.AddEdge(existingCell, cell); 
                   }
               } 
               alreadyAddedCells.Add(cell);
           }

           // Now determine the connected components of this graph 
           List result = GenerateConnectedComponents(graph);
           return result; 
        } 
        #endregion
 
        #region Private Methods

        // effects: Returns true iff cell1 is an extent at the end of cell2's
        // relationship set or vice versa 
        private static bool AreCellsConnectedViaRelationship(Cell cell1, Cell cell2) {
            AssociationSet cRelationSet1 = cell1.CQuery.Extent as AssociationSet; 
            AssociationSet cRelationSet2 = cell2.CQuery.Extent as AssociationSet; 
            if (cRelationSet1 != null && MetadataHelper.IsExtentAtSomeRelationshipEnd(cRelationSet1, cell2.CQuery.Extent)) {
                return true; 
            }
            if (cRelationSet2 != null && MetadataHelper.IsExtentAtSomeRelationshipEnd(cRelationSet2, cell1.CQuery.Extent)) {
                return true;
            } 
            return false;
        } 
        // effects: Given a graph of cell groups, returns a list of cellgroup 
        // such that each cellgroup contains all the cells that are in the
        // same connected component 
        private static List GenerateConnectedComponents(UndirectedGraph graph) {
            KeyToListMap groupMap = graph.GenerateConnectedComponents();

            // Run through the list of groups and generate the merged groups 
            List result = new List();
            foreach (int setNum in groupMap.Keys) { 
                ReadOnlyCollection cellsInComponent = groupMap.ListForKey(setNum); 
                CellGroup component = new CellGroup(cellsInComponent);
                result.Add(component); 
            }
            return result;
        }
 
        // effects: Returns true iff there is a foreign key constraint
        // between cell1 and cell2's S extents 
        private bool OverlapViaForeignKeys(Cell cell1, Cell cell2) { 
            EntitySetBase sExtent1 = cell1.SQuery.Extent;
            EntitySetBase sExtent2 = cell2.SQuery.Extent; 

            foreach (ForeignConstraint constraint in m_foreignKeyConstraints) {
                if (sExtent1.Equals(constraint.ParentTable) && sExtent2.Equals(constraint.ChildTable) ||
                    sExtent2.Equals(constraint.ParentTable) && sExtent1.Equals(constraint.ChildTable)) { 
                    return true;
                } 
            } 
            return false;
        } 
        #endregion

        internal override void ToCompactString(StringBuilder builder) {
            Cell.CellsToBuilder(builder, m_cells); 
        }
    } 
} 

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
//---------------------------------------------------------------------- 
// 
//      Copyright (c) Microsoft Corporation.  All rights reserved.
// 
// 
// @owner [....]
// @backupOwner [....] 
//--------------------------------------------------------------------- 

 
using System.Data.Common.Utils;
using System.Data.Mapping.ViewGeneration.Structures;
using System.Collections.Generic;
using System.Data.Mapping.ViewGeneration.Validation; 
using System.Text;
using System.Data.Mapping.Update.Internal; 
using System.Collections.ObjectModel; 
using System.Data.Metadata.Edm;
 
namespace System.Data.Mapping.ViewGeneration {

    using CellGroup = Set;
 
    // This class is responsible for partitioning cells into groups of cells
    // that are related and for which view generation needs to be done together 
    internal class CellPartitioner : InternalBase { 

        #region Constructor 
        // effects: Creates a partitioner for cells with extra information
        // about foreign key constraints
        internal CellPartitioner(IEnumerable cells, IEnumerable foreignKeyConstraints) {
            m_foreignKeyConstraints = foreignKeyConstraints; 
            m_cells = cells;
        } 
        #endregion 

        #region Fields 
        private IEnumerable m_cells;
        private IEnumerable m_foreignKeyConstraints;
        #endregion
 
        #region Available Methods
        // effects: Given a list of cells, segments them into multiple 
        // "groups" such that view generation (including validation) of one 
        // group can be done independently of another group. Returns the
        // groups as a list (uses the foreign key information as well) 
        internal List GroupRelatedCells() {
            // If two cells share the same C or S, we place them in the same group
            // For each cell, determine the Cis and Sis that it refers
            // to. For every Ci (Si), keep track of the cells that Ci is 
            // contained in. At the end, run through the Cis and Sis and do a
            // "connected components" algorithm to determine partitions 
 
            // Now form a graph between different cells -- then compute the connected
            // components in it 
            UndirectedGraph graph = new UndirectedGraph(EqualityComparer.Default);

            List alreadyAddedCells = new List();
            // For each extent, add an edge between it and all previously 
            // added extents with which it overlaps
 
            foreach (Cell cell in m_cells) { 
                graph.AddVertex(cell);
                // Add an edge from this cell to the already added cells 
                EntitySetBase firstCExtent = cell.CQuery.Extent;
                EntitySetBase firstSExtent = cell.SQuery.Extent;
                foreach (Cell existingCell in alreadyAddedCells) {
                    EntitySetBase secondCExtent = existingCell.CQuery.Extent; 
                    EntitySetBase secondSExtent = existingCell.SQuery.Extent;
 
                    // Add an edge between cell and existingCell if 
                    // * They have the same C or S extent
                    // * They are linked via a foreign key between the S extents 
                    // * They are linked via a relationship
                    bool sameExtent = secondCExtent.Equals(firstCExtent) || secondSExtent.Equals(firstSExtent);
                    bool linkViaForeignKey = OverlapViaForeignKeys(cell, existingCell);
                    bool linkViaRelationship = AreCellsConnectedViaRelationship(cell, existingCell); 

                    if (sameExtent || linkViaForeignKey || linkViaRelationship) { 
                       graph.AddEdge(existingCell, cell); 
                   }
               } 
               alreadyAddedCells.Add(cell);
           }

           // Now determine the connected components of this graph 
           List result = GenerateConnectedComponents(graph);
           return result; 
        } 
        #endregion
 
        #region Private Methods

        // effects: Returns true iff cell1 is an extent at the end of cell2's
        // relationship set or vice versa 
        private static bool AreCellsConnectedViaRelationship(Cell cell1, Cell cell2) {
            AssociationSet cRelationSet1 = cell1.CQuery.Extent as AssociationSet; 
            AssociationSet cRelationSet2 = cell2.CQuery.Extent as AssociationSet; 
            if (cRelationSet1 != null && MetadataHelper.IsExtentAtSomeRelationshipEnd(cRelationSet1, cell2.CQuery.Extent)) {
                return true; 
            }
            if (cRelationSet2 != null && MetadataHelper.IsExtentAtSomeRelationshipEnd(cRelationSet2, cell1.CQuery.Extent)) {
                return true;
            } 
            return false;
        } 
        // effects: Given a graph of cell groups, returns a list of cellgroup 
        // such that each cellgroup contains all the cells that are in the
        // same connected component 
        private static List GenerateConnectedComponents(UndirectedGraph graph) {
            KeyToListMap groupMap = graph.GenerateConnectedComponents();

            // Run through the list of groups and generate the merged groups 
            List result = new List();
            foreach (int setNum in groupMap.Keys) { 
                ReadOnlyCollection cellsInComponent = groupMap.ListForKey(setNum); 
                CellGroup component = new CellGroup(cellsInComponent);
                result.Add(component); 
            }
            return result;
        }
 
        // effects: Returns true iff there is a foreign key constraint
        // between cell1 and cell2's S extents 
        private bool OverlapViaForeignKeys(Cell cell1, Cell cell2) { 
            EntitySetBase sExtent1 = cell1.SQuery.Extent;
            EntitySetBase sExtent2 = cell2.SQuery.Extent; 

            foreach (ForeignConstraint constraint in m_foreignKeyConstraints) {
                if (sExtent1.Equals(constraint.ParentTable) && sExtent2.Equals(constraint.ChildTable) ||
                    sExtent2.Equals(constraint.ParentTable) && sExtent1.Equals(constraint.ChildTable)) { 
                    return true;
                } 
            } 
            return false;
        } 
        #endregion

        internal override void ToCompactString(StringBuilder builder) {
            Cell.CellsToBuilder(builder, m_cells); 
        }
    } 
} 

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

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