GeneratedView.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 / GeneratedView.cs / 1305376 / GeneratedView.cs

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

using System.Data.Common.Utils; 
using System.Data.Common.CommandTrees;
using System.Data.Common.EntitySql;
using System.Text;
using System.Collections.Generic; 
using System.Data.Mapping.ViewGeneration.Utils;
using System.Diagnostics; 
using System.Data.Metadata.Edm; 
using System.Data.Common.CommandTrees.Internal;
using System.Data.Query.InternalTrees; 
using System.Data.Query.PlanCompiler;

namespace System.Data.Mapping.ViewGeneration
{ 

    // Holds the view generated for a given OFTYPE(Extent, Type) combination 
    internal class GeneratedView : InternalBase 
    {
 
        // effects: Creates an object that stores a view, cqlString, for the combination 
        internal GeneratedView(EntitySetBase extent, EdmType type, string cqlString,
                               StorageMappingItemCollection mappingItemCollection, ConfigViewGenerator config)
        { 
            m_extent = extent;
            m_type = type; 
            m_cqlString = cqlString; 
            m_config = config;
            m_mappingItemCollection = mappingItemCollection; 

            if (m_config.IsViewTracing)
            {
                if (EqualityComparer.Default.Equals(type, extent.ElementType)) 
                {
                    Helpers.FormatTraceLine("CQL view for {0}", extent.Name); 
                } 
                else
                { 
                    Helpers.FormatTraceLine("CQL view for OFTYPE({0}, {1}.{2})", extent.Name, type.NamespaceName, type.Name);
                }
                Helpers.StringTraceLine(cqlString);
            } 

            if (m_config.IsViewTracing) 
            { 
                ParseView(m_mappingItemCollection, false /*isUserSpecified*/);
            } 
        }

        internal GeneratedView(EntitySetBase extent, EdmType type, DbQueryCommandTree commandTree, StorageMappingItemCollection mappingItemCollection, ConfigViewGenerator config)
        { 
            m_extent = extent;
            m_type = type; 
            m_cqlString = "Foreign Key Association Set View"; 
            m_commandTree = commandTree;
            m_config = config; 
            m_mappingItemCollection = mappingItemCollection;
        }

        #region Fields 
        private EntitySetBase m_extent;
        private EdmType m_type; 
        private string m_cqlString; 
        private DbQueryCommandTree m_commandTree; //We cache CQTs for Update Views sicne that is the one update stack works of.
        private Node m_internalTreeNode;  //we cache IQTs for Query Views since that is the one query stack works of. 
        private ConfigViewGenerator m_config;
        private DiscriminatorMap m_discriminatorMap;
        private StorageMappingItemCollection m_mappingItemCollection;
        #endregion 

        #region Properties 
        internal EntitySetBase Extent 
        {
            get { return m_extent; } 
        }

        internal EdmType EntityType
        { 
            get { return m_type; }
        } 
 
        internal string CqlString
        { 
            get { return m_cqlString; }
        }

        internal DiscriminatorMap DiscriminatorMap 
        {
            get { return m_discriminatorMap; } 
        } 
        #endregion
 
        #region Methods
        /// 
        /// Parses and validates a user-defined query mapping view. Outputs errors if any.
        ///  
        internal IEnumerable ParseUserSpecifiedView(StorageSetMapping setMapping, EntityTypeBase elementType, bool includeSubtypes)
        { 
 
            m_commandTree = ParseView(m_mappingItemCollection, true);
 
            // Verify that all expressions appearing in the view are supported.
            foreach (var error in ViewValidator.ValidateQueryView(m_commandTree, setMapping, elementType, includeSubtypes))
            {
                yield return error; 
            }
 
            // Verify that the result type of the query view is assignable to the element type of the entityset 
            CollectionType queryResultType = (m_commandTree.Query.ResultType.EdmType) as CollectionType;
            if ((queryResultType == null) || (!setMapping.Set.ElementType.IsAssignableFrom(queryResultType.TypeUsage.EdmType))) 
            {
                EdmSchemaError error = new EdmSchemaError(System.Data.Entity.Strings.Mapping_Invalid_QueryView_Type_1(setMapping.Set.Name),
                                           (int)StorageMappingErrorCode.InvalidQueryViewResultType, EdmSchemaErrorSeverity.Error,
                                           setMapping.EntityContainerMapping.SourceLocation, setMapping.StartLineNumber, setMapping.StartLinePosition); 
                yield return error;
            } 
        } 

        // effects: Given an extent and its corresponding view, invokes the 
        // parser to check if the view definition is syntactically correct
        // Returns true iff the parsing succeeds
        private DbQueryCommandTree ParseView(StorageMappingItemCollection mappingItemCollection, bool isUserSpecified)
        { 
            // We do not catch any internal exceptions any more
            m_config.StartSingleWatch(PerfType.ViewParsing); 
            //If it is a user specified view, 
            //allow all queries. Otherwise parse the view in a restricted mode.
            ParserOptions.CompilationMode compilationMode = ParserOptions.CompilationMode.RestrictedViewGenerationMode; 
            if (isUserSpecified)
            {
                compilationMode = ParserOptions.CompilationMode.UserViewGenerationMode;
            } 
            DbQueryCommandTree commandTree = (DbQueryCommandTree)ExternalCalls.CompileView(CqlString, mappingItemCollection, compilationMode);
 
            // For non user-specified views, perform simplification 
            if (!isUserSpecified)
            { 
                commandTree = ViewSimplifier.SimplifyView(m_extent, commandTree);
            }

            // See if the view matches the "discriminated" pattern (allows simplification of generated store commands) 
            if (m_extent.BuiltInTypeKind == BuiltInTypeKind.EntitySet)
            { 
                DiscriminatorMap discriminatorMap; 
                if (DiscriminatorMap.TryCreateDiscriminatorMap((EntitySet)m_extent, commandTree.Query, out discriminatorMap))
                { 
                    m_discriminatorMap = discriminatorMap;
                }
            }
            m_config.StopSingleWatch(PerfType.ViewParsing); 
            return commandTree;
        } 
 
        internal DbQueryCommandTree GetCommandTree(MetadataWorkspace workspace)
        { 
            //Ask command trees only for C space entity sets
            Debug.Assert(m_extent.EntityContainer.DataSpace == DataSpace.SSpace, "CQT should be asked only for update view");
            if (m_commandTree == null)
            { 
                m_commandTree = ParseView((StorageMappingItemCollection)workspace.GetItemCollection(DataSpace.CSSpace), false);
            } 
            return m_commandTree; 
        }
 
        internal Node GetInternalTree(MetadataWorkspace workspace)
        {
            Debug.Assert(m_extent.EntityContainer.DataSpace == DataSpace.CSpace, "Internal Tree should be asked only for query view");
            if (m_internalTreeNode == null) 
            {
                DbQueryCommandTree tree = m_commandTree ?? ParseView((StorageMappingItemCollection)workspace.GetItemCollection(DataSpace.CSSpace), false); 
                // Convert this into an ITree first 
                Command itree = ITreeGenerator.Generate(tree, this.DiscriminatorMap);
                // Pull out the root physical project-op, and copy this itree into our own itree 
                PlanCompiler.Assert(itree.Root.Op.OpType == OpType.PhysicalProject,
                    "Expected a physical projectOp at the root of the tree - found " + itree.Root.Op.OpType);
                // #554756: VarVec enumerators are not cached on the shared Command instance.
                itree.DisableVarVecEnumCaching(); 
                m_internalTreeNode = itree.Root.Child0;
            } 
            return m_internalTreeNode; 
        }
        #endregion 

        #region String Methods
        internal override void ToCompactString(StringBuilder builder)
        { 
            builder.Append("OFTYPE(")
                   .Append(Extent.Name) 
                   .Append(", ") 
                   .Append(EntityType.Name)
                   .Append(") = ") 
                   .Append(CqlString);
        }
        #endregion
    } 
}

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

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