OdbcConnectionFactory.cs source code in C# .NET

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                         / 4.0 / 4.0 / untmp / DEVDIV_TFS / Dev10 / Releases / RTMRel / ndp / fx / src / Data / System / Data / Odbc / OdbcConnectionFactory.cs / 1305376 / OdbcConnectionFactory.cs
                        
                        
                            //------------------------------------------------------------------------------ 
// 
//      Copyright (c) Microsoft Corporation.  All rights reserved.
// 
// [....] 
// [....]
//----------------------------------------------------------------------------- 
 
namespace System.Data.Odbc
{ 
    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 OdbcConnectionFactory : DbConnectionFactory {
        private OdbcConnectionFactory() : base() {}
        // At this time, the ODBC 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 _MetaData           = ":MetaDataXml"; 
        private const string _defaultMetaDataXml = "defaultMetaDataXml";
 
        public static readonly OdbcConnectionFactory SingletonInstance = new OdbcConnectionFactory();

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

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

        override protected DbConnectionPoolGroupOptions CreateConnectionPoolGroupOptions( DbConnectionOptions connectionOptions ) {
            // At this time, the ODBC provider only supports native pooling so we
            // simply return NULL to indicate that. 
            return null;
        } 
 
        override internal DbConnectionPoolGroupProviderInfo CreateConnectionPoolGroupProviderInfo (DbConnectionOptions connectionOptions) {
            return new OdbcConnectionPoolGroupProviderInfo(); 
        }

        // 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;

            OdbcConnection odbcOuterConnection = ((OdbcConnectionOpen)internalConnection).OuterConnection; 
            Debug.Assert(odbcOuterConnection != null,"outer connection may not be null.");
 
            NameValueCollection settings = (NameValueCollection)PrivilegedConfigurationManager.GetSection("system.data.odbc"); 
            Stream XMLStream =null;
 
            // get the DBMS Name
            object driverName = null;
            string stringValue = odbcOuterConnection.GetInfoStringUnhandled(ODBC32.SQL_INFO.DRIVER_NAME);
            if (stringValue != null) { 
                driverName = stringValue;
            } 
 
            if (settings != null){
 
                string [] values = null;
                string metaDataXML = null;
                // first try to get the provider specific xml
 
                // if driver name is not supported we can't build the settings key needed to
                // get the provider specific XML path 
                if (driverName != null){ 
                    metaDataXML =  ((string)driverName) + _MetaData;
                    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 an XML file get it 
                if (values != null) {
                    XMLStream = ADP.GetXmlStreamFromValues(values,metaDataXML);
                }
            } 

            // use the embedded xml if the user did not over ride it 
            if (XMLStream == null){ 
                XMLStream = System.Reflection.Assembly.GetExecutingAssembly().GetManifestResourceStream("System.Data.Odbc.OdbcMetaData.xml");
                cacheMetaDataFactory = true; 
            }

            Debug.Assert (XMLStream != null,"XMLstream may not be null.");
 
            String versionString = odbcOuterConnection.GetInfoStringUnhandled(ODBC32.SQL_INFO.DBMS_VER);
 
            return new OdbcMetaDataFactory (XMLStream, 
                                            versionString,
                                            versionString, 
                                            odbcOuterConnection);
        }

        override internal DbConnectionPoolGroup GetConnectionPoolGroup(DbConnection connection) { 
            OdbcConnection c = (connection as OdbcConnection);
            if (null != c) { 
                return c.PoolGroup; 
            }
            return null; 
        }

        override internal DbConnectionInternal GetInnerConnection(DbConnection connection) {
            OdbcConnection c = (connection as OdbcConnection); 
            if (null != c) {
                return c.InnerConnection; 
            } 
            return null;
        } 

        override protected int GetObjectId(DbConnection connection) {
            OdbcConnection c = (connection as OdbcConnection);
            if (null != c) { 
                return c.ObjectID;
            } 
            return 0; 
        }
 
        override internal void PermissionDemand(DbConnection outerConnection) {
            OdbcConnection c = (outerConnection as OdbcConnection);
            if (null != c) {
                c.PermissionDemand(); 
            }
        } 
 
        override internal void SetConnectionPoolGroup(DbConnection outerConnection, DbConnectionPoolGroup poolGroup) {
            OdbcConnection c = (outerConnection as OdbcConnection); 
            if (null != c) {
                c.PoolGroup = poolGroup;
            }
        } 

        override internal void SetInnerConnectionEvent(DbConnection owningObject, DbConnectionInternal to) { 
            OdbcConnection c = (owningObject as OdbcConnection); 
            if (null != c) {
                c.SetInnerConnectionEvent(to); 
            }
        }

        override internal bool SetInnerConnectionFrom(DbConnection owningObject, DbConnectionInternal to, DbConnectionInternal from) { 
            OdbcConnection c = (owningObject as OdbcConnection);
            if (null != c) { 
                return c.SetInnerConnectionFrom(to, from); 
            }
            return false; 
        }

        override internal void SetInnerConnectionTo(DbConnection owningObject, DbConnectionInternal to) {
            OdbcConnection c = (owningObject as OdbcConnection); 
            if (null != c) {
                c.SetInnerConnectionTo(to); 
            } 
        }
 


    }
} 


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

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