CacheForPrimitiveTypes.cs source code in C# .NET

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

using System; 
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Data.EntityModel;
using System.Diagnostics; 
using System.Text;
using System.Xml.Serialization; 
using System.Xml; 
using System.Xml.Schema;
using System.IO; 
using System.Data.Common;
using System.Globalization;

namespace System.Data.Metadata.Edm 
{
    internal class CacheForPrimitiveTypes 
    { 
        #region Fields
        // The primitive type kind is a list of enum which the EDM model 
        // Every specific instantiation of the model should map their
        // primitive types to the edm primitive types.

        // In this class, primitive type is to be cached 

        // Key for the cache: primitive type kind 
        // Value for the cache: List.  A list is used because there an be multiple types mapping to the 
        // same primitive type kind.  For example, sqlserver has multiple string types.
 
        private List[] _primitiveTypeMap = new List[EdmConstants.NumPrimitiveTypes];
        #endregion

        #region Methods 
        /// 
        /// Add the given primitive type to the primitive type cache 
        ///  
        /// The primitive type to add
        internal void Add(PrimitiveType type) 
        {
            // Get to the list
            List primitiveTypes = EntityUtil.CheckArgumentOutOfRange(_primitiveTypeMap, (int)type.PrimitiveTypeKind, "primitiveTypeKind");
 
            // If there isn't a list for the given model type, create one and add it
            if (primitiveTypes == null) 
            { 
                primitiveTypes = new List();
                primitiveTypes.Add(type); 
                _primitiveTypeMap[(int)type.PrimitiveTypeKind] = primitiveTypes;
            }
            else
            { 
                primitiveTypes.Add(type);
            } 
        } 

        ///  
        /// Try and get the mapped type for the given primitiveTypeKind in the given dataspace
        /// 
        /// The primitive type kind of the primitive type to retrieve
        /// The facets to use in picking the primitive type 
        /// The resulting type
        /// Whether a type was retrieved or not 
        internal bool TryGetType(PrimitiveTypeKind primitiveTypeKind, IEnumerable facets, out PrimitiveType type) 
        {
            type = null; 

            // Now, see if we have any types for this model type, if so, loop through to find the best matching one
            List primitiveTypes = EntityUtil.CheckArgumentOutOfRange(_primitiveTypeMap, (int)primitiveTypeKind, "primitiveTypeKind");
            if ((null != primitiveTypes) && (0 < primitiveTypes.Count)) 
            {
                if (primitiveTypes.Count == 1) 
                { 
                    type = primitiveTypes[0];
                    return true; 
                }

                if (facets == null)
                { 
                    FacetDescription[] facetDescriptions = EdmProviderManifest.GetInitialFacetDescriptions(primitiveTypeKind);
                    if (facetDescriptions == null) 
                    { 
                        type = primitiveTypes[0];
                        return true; 
                    }

                    Debug.Assert(facetDescriptions.Length > 0);
                    facets = CacheForPrimitiveTypes.CreateInitialFacets(facetDescriptions); 
                }
 
                Debug.Assert(type == null, "type must be null here"); 
                bool isMaxLengthSentinel = false;
 
                // Create a dictionary of facets for easy lookup
                foreach (Facet facet in facets)
                {
                    if ((primitiveTypeKind == PrimitiveTypeKind.String || 
                         primitiveTypeKind == PrimitiveTypeKind.Binary) &&
                        facet.Value != null && 
                        facet.Name == EdmProviderManifest.MaxLengthFacetName && 
                        Helper.IsUnboundedFacetValue(facet))
                    { 
                        // MaxLength has the sentinel value. So this facet need not be added.
                        isMaxLengthSentinel = true;
                        continue;
                    } 
                }
 
                int maxLength = 0; 
                // Find a primitive type with the matching constraint
                foreach (PrimitiveType primitiveType in primitiveTypes) 
                {
                    if (isMaxLengthSentinel)
                    {
                        if (type == null) 
                        {
                            type = primitiveType; 
                            maxLength = Helper.GetFacet(primitiveType.FacetDescriptions, EdmProviderManifest.MaxLengthFacetName).MaxValue.Value; 
                        }
                        else 
                        {
                            int newMaxLength = Helper.GetFacet(primitiveType.FacetDescriptions, EdmProviderManifest.MaxLengthFacetName).MaxValue.Value;
                            if (newMaxLength > maxLength)
                            { 
                                type = primitiveType;
                                maxLength = newMaxLength; 
                            } 
                        }
                    } 
                    else
                    {
                        type = primitiveType;
                        break; 
                    }
                } 
 
                Debug.Assert(type != null);
                return true; 
            }

            return false;
        } 

        private static Facet[] CreateInitialFacets(FacetDescription[] facetDescriptions) 
        { 
            Debug.Assert(facetDescriptions != null && facetDescriptions.Length > 0);
 
            Facet[] facets = new Facet[facetDescriptions.Length];

            for (int i = 0; i < facetDescriptions.Length; ++i)
            { 
                switch (facetDescriptions[i].FacetName)
                { 
                    case DbProviderManifest.MaxLengthFacetName: 
                        facets[i] = Facet.Create(facetDescriptions[i], TypeUsage.DefaultMaxLengthFacetValue);
                        break; 

                    case DbProviderManifest.UnicodeFacetName:
                        facets[i] = Facet.Create(facetDescriptions[i], TypeUsage.DefaultUnicodeFacetValue);
                        break; 

                    case DbProviderManifest.FixedLengthFacetName: 
                        facets[i] = Facet.Create(facetDescriptions[i], TypeUsage.DefaultFixedLengthFacetValue); 
                        break;
 
                    case DbProviderManifest.PrecisionFacetName:
                        facets[i] = Facet.Create(facetDescriptions[i], TypeUsage.DefaultPrecisionFacetValue);
                        break;
 
                    case DbProviderManifest.ScaleFacetName:
                        facets[i] = Facet.Create(facetDescriptions[i], TypeUsage.DefaultScaleFacetValue); 
                        break; 

                    default: 
                        Debug.Assert(false, "Unexpected facet");
                        break;
                }
            } 

            return facets; 
        } 

        ///  
        /// Get the list of the primitive types for the given dataspace
        /// 
        /// 
        internal System.Collections.ObjectModel.ReadOnlyCollection GetTypes() 
        {
            List primitiveTypes = new List(); 
            foreach (List types in _primitiveTypeMap) 
            {
                if (null != types) 
                {
                    primitiveTypes.AddRange(types);
                }
            } 
            return primitiveTypes.AsReadOnly();
        } 
        #endregion 
    }
} 

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
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CacheForPrimitiveTypes.cs source code in C# .NET

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