SchemaManager.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 / EntityModel / SchemaObjectModel / SchemaManager.cs / 1305376 / SchemaManager.cs

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

using System; 
using System.Collections;
using System.Collections.Generic;
using System.Diagnostics;
using System.Data.Metadata.Edm; 
using System.Data.Common.Utils;
using System.Xml; 
using System.Data.Common; 
using System.Data.Entity;
using System.Linq; 

namespace System.Data.EntityModel.SchemaObjectModel
{
    internal delegate void AttributeValueNotification(string token, Action addError); 
    internal delegate DbProviderManifest ProviderManifestNeeded(Action addError);
 
    ///  
    /// Class responsible for parsing,validating a collection of schema
    ///  
    [System.Diagnostics.DebuggerDisplay("DataModel={DataModel}")]
    internal class SchemaManager
    {
        #region Instance Fields 
        // This keeps track of all the possible namespaces encountered till now. This helps in displaying the error to the
        // user - if the particular type is not found, we can report whether the namespace was invalid or the type with the 
        // given name was not found in the given namespace. This also helps in validating the namespace in the using elements 
        private readonly HashSet _namespaceLookUpTable = new HashSet(StringComparer.Ordinal);
 
        // List of all the schema types across all the schemas. This is to ensure that there is no duplicate type encountered
        // across schemas
        private readonly SchemaElementLookUpTable _schemaTypes = new SchemaElementLookUpTable();
 
        // We want to stop parsing/resolving/validation after the first 100 errors
        private const int MaxErrorCount = 100; 
 
        // delay loaded
        private DbProviderManifest _providerManifest; 
        private PrimitiveSchema _primitiveSchema;

        private readonly SchemaDataModelOption _dataModel;
        private readonly ProviderManifestNeeded _providerManifestNeeded; 
        private readonly AttributeValueNotification _providerNotification;
        private readonly AttributeValueNotification _providerManifestTokenNotification; 
        #endregion 

        #region Constructor 
        private SchemaManager(SchemaDataModelOption dataModel, AttributeValueNotification providerNotification, AttributeValueNotification providerManifestTokenNotification, ProviderManifestNeeded providerManifestNeeded)
        {
            _dataModel = dataModel;
            _providerNotification = providerNotification; 
            _providerManifestTokenNotification = providerManifestTokenNotification;
            _providerManifestNeeded = providerManifestNeeded; 
        } 
        #endregion
 
        #region Public Methods


 
        public static IList LoadProviderManifest(XmlReader xmlReader, string location,
            bool checkForSystemNamespace, out Schema schema) 
        { 
            IList schemaCollection = new List(1);
 
            DbProviderManifest providerManifest = checkForSystemNamespace ? EdmProviderManifest.Instance : null;
            IList errors = ParseAndValidate(new XmlReader[] { xmlReader },
                new string[] { location }, SchemaDataModelOption.ProviderManifestModel,
                providerManifest, out schemaCollection); 

            // In case of errors, there are no schema in the schema collection 
            if (schemaCollection.Count != 0) 
            {
                schema = schemaCollection[0]; 
            }
            else
            {
                Debug.Assert(errors.Count != 0, "There must be some error encountered"); 
                schema = null;
            } 
 
            return errors;
        } 

        public static void NoOpAttributeValueNotification(string attributeValue, Action addError) { }

        public static IList ParseAndValidate(IEnumerable xmlReaders, 
            IEnumerable sourceFilePaths, SchemaDataModelOption dataModel,
            DbProviderManifest providerManifest, 
            out IList schemaCollection) 
        {
            return ParseAndValidate(xmlReaders, 
                sourceFilePaths,
                dataModel,
                NoOpAttributeValueNotification,
                NoOpAttributeValueNotification, 
                delegate(Action addError) { return providerManifest == null ? MetadataItem.EdmProviderManifest : providerManifest; },
                out schemaCollection); 
        } 

        public static IList ParseAndValidate(IEnumerable xmlReaders, 
            IEnumerable sourceFilePaths, SchemaDataModelOption dataModel,
            AttributeValueNotification providerNotification,
            AttributeValueNotification providerManifestTokenNotification,
            ProviderManifestNeeded providerManifestNeeded, 
            out IList schemaCollection)
        { 
            SchemaManager schemaManager = new SchemaManager(dataModel, providerNotification, providerManifestTokenNotification, providerManifestNeeded); 
            var errorCollection = new List();
            schemaCollection = new List(); 
            bool errorEncountered = false;

            List filePathList;
            if (sourceFilePaths != null) 
            {
                filePathList = new List(sourceFilePaths); 
            } 
            else
            { 
                filePathList = new List();
            }

            int index = 0; 
            foreach (XmlReader xmlReader in xmlReaders)
            { 
                string location = null; 
                if (filePathList.Count <= index)
                { 
                    TryGetBaseUri(xmlReader, out location);
                }
                else
                { 
                    location = filePathList[index];
                } 
 
                Schema schema;
                schema = new Schema(schemaManager); 

                var errorsForCurrentSchema = schema.Parse(xmlReader, location);

                CheckIsSameVersion(schema, schemaCollection, errorCollection); 

                // If the number of errors exceeded the max error count, then return 
                if (UpdateErrorCollectionAndCheckForMaxErrors(errorCollection, errorsForCurrentSchema, ref errorEncountered)) 
                {
                    return errorCollection; 
                }

                // Add the schema to the collection if there are no errors. There are errors in which schema do not have any namespace.
                // Also if there is an error encountered in one of the schema, we do not need to add the remaining schemas since 
                // we will never go to the resolve phase.
                if (!errorEncountered) 
                { 
                    schemaCollection.Add(schema);
                    schemaManager.AddSchema(schema); 
                    var currentSchemaVersion = schema.SchemaVersion;
                    Debug.Assert(schemaCollection.All(s => s.SchemaVersion == currentSchemaVersion || s.SchemaVersion != XmlConstants.UndefinedVersion));
                }
                index++; 
            }
 
            // If there are no errors encountered in the parsing stage, we can proceed to the 
            // parsing and validating phase
            if (!errorEncountered) 
            {
                foreach (Schema schema in schemaCollection)
                {
                    if (UpdateErrorCollectionAndCheckForMaxErrors(errorCollection, schema.Resolve(), ref errorEncountered)) 
                    {
                        return errorCollection; 
                    } 
                }
 
                // If there are no errors encountered in the parsing stage, we can proceed to the
                // parsing and validating phase
                if (!errorEncountered)
                { 
                    foreach (Schema schema in schemaCollection)
                    { 
                        if (UpdateErrorCollectionAndCheckForMaxErrors(errorCollection, schema.ValidateSchema(), ref errorEncountered)) 
                        {
                            return errorCollection; 
                        }
                    }
                }
            } 

            return errorCollection; 
        } 

        private static bool CheckIsSameVersion(Schema schemaToBeAdded, IEnumerable schemaCollection, List errorCollection) 
        {
            if (schemaToBeAdded.SchemaVersion != XmlConstants.UndefinedVersion && schemaCollection.Count() > 0)
            {
                if (schemaCollection.Any(s => s.SchemaVersion != XmlConstants.UndefinedVersion && s.SchemaVersion != schemaToBeAdded.SchemaVersion)) 
                {
                    errorCollection.Add( 
                    new EdmSchemaError( 
                        Strings.CannotLoadDifferentVersionOfSchemaInTheSameItemCollection,
                        (int)ErrorCode.CannotLoadDifferentVersionOfSchemaInTheSameItemCollection, 
                        EdmSchemaErrorSeverity.Error));
                }
            }
            return true; 
        }
 
        ///  
        /// Add the namespace of the given schema to the namespace lookup table
        ///  
        public void AddSchema(Schema schema)
        {
            Debug.Assert(schema.DataModel == _dataModel, "DataModel must match");
 
            if (_namespaceLookUpTable.Count == 0 && schema.DataModel != SchemaDataModelOption.ProviderManifestModel)
            { 
                // Add the primitive type namespace to the namespace look up table 
                if (this.PrimitiveSchema.Namespace != null)
                { 
                    _namespaceLookUpTable.Add(this.PrimitiveSchema.Namespace);
                }
            }
 
            // Add the namespace to the namespaceLookUpTable.
            // Its okay to have multiple schemas with the same namespace 
            _namespaceLookUpTable.Add(schema.Namespace); 
        }
 
        /// 
        /// Resolve the type - if the type is not found, return appropriate error
        /// 
        ///  
        public bool TryResolveType(string namespaceName, string typeName, out SchemaType schemaType)
        { 
            // For resolving entity container names, namespace can be null 
            string fullyQualifiedName = String.IsNullOrEmpty(namespaceName) ? typeName : namespaceName + "." + typeName;
 
            schemaType = SchemaTypes.LookUpEquivalentKey(fullyQualifiedName);
            if (schemaType != null)
            {
                return true; 
            }
 
            return false; 
        }
 
        /// 
        /// Returns true if this is a valid namespace name or else returns false
        /// 
        public bool IsValidNamespaceName(string namespaceName) 
        {
            return _namespaceLookUpTable.Contains(namespaceName); 
        } 
        #endregion // Public Methods
 
        #region Private Methods

        /// 
        /// Checks if the xml reader has base uri. If it doesn't have, it adds error, other 
        /// returns the location from the base uri
        ///  
        ///  
        internal static bool TryGetBaseUri(XmlReader xmlReader, out string location)
        { 
            string baseUri = xmlReader.BaseURI;
            Uri uri = null;

            if (!string.IsNullOrEmpty(baseUri) && 
                 Uri.TryCreate(baseUri, UriKind.Absolute, out uri) &&
                 uri.Scheme == "file") 
            { 
                location = Helper.GetFileNameFromUri(uri);
                return true; 
            }
            else
            {
                location = null; 
                return false;
            } 
        } 

        ///  
        /// Add the given list of newErrors to the error collection. If there is a error in the new errors,
        /// it sets the errorEncountered to true. Returns true if the number of errors encountered is more
        /// than max errors
        ///  
        /// 
        private static bool UpdateErrorCollectionAndCheckForMaxErrors(List errorCollection, 
            IList newErrors, ref bool errorEncountered) 
        {
            // If we have encountered error already in one of the schemas, then we don't need to check for errors in the remaining schemas. 
            // Just keep aggregating the errors and throw them at the end.
            if (!errorEncountered)
            {
                if (!MetadataHelper.CheckIfAllErrorsAreWarnings(newErrors)) 
                {
                    errorEncountered = true; 
                } 
            }
 
            // Add the new errors to the error collection
            errorCollection.AddRange(newErrors);

            if (errorEncountered && 
                errorCollection.Where(e => e.Severity == EdmSchemaErrorSeverity.Error).Count() > MaxErrorCount)
            { 
                return true; 
            }
            return false; 
        }
        #endregion

        #region Internal Properties 

        internal SchemaElementLookUpTable SchemaTypes 
        { 
            get
            { 
                return _schemaTypes;
            }
        }
 
        internal DbProviderManifest GetProviderManifest(Action addError)
        { 
            if (_providerManifest == null) 
            {
                _providerManifest = _providerManifestNeeded(addError); 
            }
            return _providerManifest;
        }
 
        internal SchemaDataModelOption DataModel { get { return _dataModel; } }
 
        internal void EnsurePrimitiveSchemaIsLoaded() 
        {
            if (_primitiveSchema == null) 
            {
                _primitiveSchema = new PrimitiveSchema(this);
            }
        } 

        internal PrimitiveSchema PrimitiveSchema 
        { 
            get
            { 
                return _primitiveSchema;
            }
        }
 
        internal AttributeValueNotification ProviderNotification
        { 
            get 
            {
                return _providerNotification; 
            }
        }

        internal AttributeValueNotification ProviderManifestTokenNotification 
        {
            get 
            { 
                return _providerManifestTokenNotification;
            } 
        }

        #endregion
    } 
}

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

Link Menu

Network programming in C#, Network Programming in VB.NET, Network Programming in .NET
This book is available now!
Buy at Amazon US or
Buy at Amazon UK