OleDbConnectionFactory.cs source code in C# .NET

                        Code:
                         / 4.0 / 4.0 / untmp / DEVDIV_TFS / Dev10 / Releases / RTMRel / ndp / fx / src / Data / System / Data / OleDb / OleDbConnectionFactory.cs / 1305376 / OleDbConnectionFactory.cs
                        
                        
                            //------------------------------------------------------------------------------ 
// 
//      Copyright (c) Microsoft Corporation.  All rights reserved.
// 
// [....] 
// [....]
//----------------------------------------------------------------------------- 
 
namespace System.Data.OleDb
{ 
    using System;
    using System.Data.Common;
    using System.Data.ProviderBase;
    using System.Diagnostics; 
    using System.Collections.Specialized;
    using System.Configuration; 
    using System.IO; 
    using System.Runtime.Versioning;
 
    sealed internal class OleDbConnectionFactory : DbConnectionFactory {
        private OleDbConnectionFactory() : base() {}
        // At this time, the OleDb Managed Provider doesn't have any connection pool
        // counters because we'd only confuse people with "non-pooled" connections 
        // that are actually being pooled by the native pooler.
 
        private const string _metaDataXml           = ":MetaDataXml"; 
        private const string _defaultMetaDataXml    = "defaultMetaDataXml";
 
        public static readonly OleDbConnectionFactory SingletonInstance = new OleDbConnectionFactory();

        override public DbProviderFactory ProviderFactory {
            get { 
                return OleDbFactory.Instance;
            } 
        } 

        override protected DbConnectionInternal CreateConnection(DbConnectionOptions options, object poolGroupProviderInfo, DbConnectionPool pool, DbConnection owningObject) { 
            DbConnectionInternal result = new OleDbConnectionInternal((OleDbConnectionString)options, (OleDbConnection)owningObject);
            return result;
        }
 
        protected override DbConnectionOptions CreateConnectionOptions(string connectionString, DbConnectionOptions previous) {
            Debug.Assert(!ADP.IsEmpty(connectionString), "null connectionString"); 
            OleDbConnectionString result = new OleDbConnectionString(connectionString, (null != previous)); 
            return result;
        } 

        // SxS (VSDD 545786): metadata files are opened from <.NetRuntimeFolder>\CONFIG\
        // this operation is safe in SxS because the file is opened in read-only mode and each NDP runtime accesses its own copy of the metadata
        // under the runtime folder. 
        [ResourceExposure(ResourceScope.None)]
        [ResourceConsumption(ResourceScope.Machine, ResourceScope.Machine)] 
        override protected DbMetaDataFactory CreateMetaDataFactory(DbConnectionInternal internalConnection, out bool cacheMetaDataFactory){ 

            Debug.Assert (internalConnection != null,"internalConnection may not be null."); 
            cacheMetaDataFactory = false;


            OleDbConnectionInternal oleDbInternalConnection = (OleDbConnectionInternal) internalConnection; 
            OleDbConnection oleDbOuterConnection = oleDbInternalConnection.Connection;
            Debug.Assert(oleDbOuterConnection != null,"outer connection may not be null."); 
 
            NameValueCollection settings = (NameValueCollection)PrivilegedConfigurationManager.GetSection("system.data.oledb");
            Stream XMLStream =null; 
            String providerFileName =  oleDbOuterConnection.GetDataSourcePropertyValue(OleDbPropertySetGuid.DataSourceInfo,ODB.DBPROP_PROVIDERFILENAME) as string;

            if (settings != null){
 
                string [] values = null;
                string metaDataXML = null; 
                // first try to get the provider specific xml 

                // if providerfilename is not supported we can't build the settings key needed to 
                // get the provider specific XML path
                if (providerFileName != null){
                    metaDataXML =  providerFileName + _metaDataXml;
                    values = settings.GetValues(metaDataXML); 
                }
 
                // if we did not find provider specific xml see if there is new default xml 
                if (values == null) {
                    metaDataXML =_defaultMetaDataXml; 
                    values = settings.GetValues(metaDataXML);
                }

                // If there is new XML get it 
                if (values != null) {
                    XMLStream = ADP.GetXmlStreamFromValues(values,metaDataXML); 
                } 
            }
 
            // if the xml was not obtained from machine.config use the embedded XML resource
            if (XMLStream == null) {
                XMLStream = System.Reflection.Assembly.GetExecutingAssembly().GetManifestResourceStream("System.Data.OleDb.OleDbMetaData.xml");
                cacheMetaDataFactory = true; 
            }
 
            Debug.Assert (XMLStream != null,"XMLstream may not be null."); 

            // using the ServerVersion as the NormalizedServerVersion. Doing this for two reasons 
            //  1) The Spec for DBPROP_DBMSVER normalizes the ServerVersion
            //  2) for OLE DB its the only game in town
            return new OleDbMetaDataFactory (XMLStream,
                                             oleDbInternalConnection.ServerVersion, 
                                             oleDbInternalConnection.ServerVersion,
                                             oleDbInternalConnection.GetSchemaRowsetInformation()); 
        } 

        override protected DbConnectionPoolGroupOptions CreateConnectionPoolGroupOptions(DbConnectionOptions connectionOptions) { 
            return null;
        }

        override internal DbConnectionPoolGroupProviderInfo CreateConnectionPoolGroupProviderInfo (DbConnectionOptions connectionOptions) { 
            return new OleDbConnectionPoolGroupProviderInfo();
        } 
 
        override internal DbConnectionPoolGroup GetConnectionPoolGroup(DbConnection connection) {
            OleDbConnection c = (connection as OleDbConnection); 
            if (null != c) {
                return c.PoolGroup;
            }
            return null; 
        }
 
        override internal DbConnectionInternal GetInnerConnection(DbConnection connection) { 
            OleDbConnection c = (connection as OleDbConnection);
            if (null != c) { 
                return c.InnerConnection;
            }
            return null;
        } 

        override protected int GetObjectId(DbConnection connection) { 
            OleDbConnection c = (connection as OleDbConnection); 
            if (null != c) {
                return c.ObjectID; 
            }
            return 0;
        }
 
        override internal void PermissionDemand(DbConnection outerConnection) {
            OleDbConnection c = (outerConnection as OleDbConnection); 
            if (null != c) { 
                c.PermissionDemand();
            } 
        }

        override internal void SetConnectionPoolGroup(DbConnection outerConnection, DbConnectionPoolGroup poolGroup) {
            OleDbConnection c = (outerConnection as OleDbConnection); 
            if (null != c) {
                c.PoolGroup = poolGroup; 
            } 
        }
 
        override internal void SetInnerConnectionEvent(DbConnection owningObject, DbConnectionInternal to) {
            OleDbConnection c = (owningObject as OleDbConnection);
            if (null != c) {
                c.SetInnerConnectionEvent(to); 
            }
        } 
 
        override internal bool SetInnerConnectionFrom(DbConnection owningObject, DbConnectionInternal to, DbConnectionInternal from) {
            OleDbConnection c = (owningObject as OleDbConnection); 
            if (null != c) {
                return c.SetInnerConnectionFrom(to, from);
            }
            return false; 
        }
 
        override internal void SetInnerConnectionTo(DbConnection owningObject, DbConnectionInternal to) { 
            OleDbConnection c = (owningObject as OleDbConnection);
            if (null != c) { 
                c.SetInnerConnectionTo(to);
            }
        }
 
    }
} 
 

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