LazyTextWriterCreator.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 / DataEntityDesign / Design / System / Data / EntityModel / LazyTextWriterCreator.cs / 1305376 / LazyTextWriterCreator.cs
                        

                        
                            //---------------------------------------------------------------------- 
// 
//      Copyright (c) Microsoft Corporation.  All rights reserved.
// 
// 
// @owner       [....]
// @backupOwner [....] 
//--------------------------------------------------------------------- 
using System;
using System.Collections.Generic; 
using System.Linq;
using System.Text;
using System.IO;
using System.Diagnostics; 
using System.Runtime.Versioning;
 
namespace System.Data.Entity.Design 
{
    ///  
    /// This class is responsible for abstracting the knowledge
    /// of whether the user provided a TextWriter or a FilePath.
    ///
    /// If the user gave us a filePath we try not to create the TextWriter 
    /// till we absolutely need it in order to prevent the file from being created
    /// in error cases. 
    ///  
    internal class LazyTextWriterCreator : IDisposable
    { 
        private bool _ownTextWriter;
        private TextWriter _writer = null;
        private string _targetFilePath = null;
 
        internal LazyTextWriterCreator(TextWriter writer)
        { 
            Debug.Assert(writer != null, "writer parameter is null"); 

            _ownTextWriter = false; 
            _writer = writer;
        }

        [ResourceExposure(ResourceScope.Machine)] //The target file path is used to open a stream which is a machine resource. 
        internal LazyTextWriterCreator(string targetFilePath)
        { 
            Debug.Assert(targetFilePath != null, "targetFilePath parameter is null"); 

            _ownTextWriter = true; 
            _targetFilePath = targetFilePath;
        }

        [ResourceExposure(ResourceScope.None)] //The resource( target file path) is not exposed to the callers of this method 
        [ResourceConsumption(ResourceScope.Machine, ResourceScope.Machine)] //For StreamWriter constructor and we pick
                                                                            //the target file path from class variable. 
        internal TextWriter GetOrCreateTextWriter() 
        {
            if (_writer == null) 
            {
                // lazy creating the writer
                _writer = new StreamWriter(_targetFilePath);
            } 
            return _writer;
        } 
 
        internal string TargetFilePath
        { 
            get { return _targetFilePath; }
        }

        internal bool IsUserSuppliedTextWriter 
        {
            get { return !_ownTextWriter; } 
        } 

        public void Dispose() 
        {
            // Technically, calling GC.SuppressFinalize is not required because the class does not
            // have a finalizer, but it does no harm, protects against the case where a finalizer is added
            // in the future, and prevents an FxCop warning. 
            GC.SuppressFinalize(this);
            if (_ownTextWriter && _writer != null) 
            { 
                _writer.Dispose();
            } 
        }
    }
}

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

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