StreamHelper.cs source code in C# .NET

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Code:

                         / DotNET / DotNET / 8.0 / untmp / WIN_WINDOWS / lh_tools_devdiv_wpf / Windows / wcp / TrustUi / MS / Internal / documents / Application / StreamHelper.cs / 1 / StreamHelper.cs
                        

                        
                            //------------------------------------------------------------------------------ 
// 
//    Copyright (C) Microsoft Corporation.  All rights reserved. 
//
//  
// A static utilitly class for stream related functions.
//  
// 
// History:
//  08/28/2005: [....]: Initial implementation. 
//-----------------------------------------------------------------------------

using System;
using System.IO; 

namespace MS.Internal.Documents.Application 
{ 
/// 
/// A static utilitly class for stream related functions. 
/// 
internal static class StreamHelper
{
    #region Internal Methods 
    //-------------------------------------------------------------------------
    // Internal Methods 
    //------------------------------------------------------------------------- 

    ///  
    /// A simple stream copy from one to another.
    /// 
    /// 
    /// If anyone knows of an existing mechanism please contact me and 
    /// I will remove this code.
    /// 
    /// Performance:  This block of code is likely to be the most heavily used 
    /// code with large packages.  We should explorer other designs if it
    /// becomes an issue. 
    /// 
    /// The Stream to read from.
    /// The Stream to write to.
    internal static void CopyStream(Stream source, Stream target) 
    {
        int bufferSize = 4096; // Arbitrary Value 
        byte[] buffer = new byte[bufferSize]; 

        long originalSourcePosition = source.Position; 
        long originalTargetPosition = target.Position;

        // move to the start
        source.Position = 0; 
        target.Position = 0;
 
        // ensure we have enough space 
        long size = source.Length;
        target.SetLength(size); 

        // copy the stream syncronously
        int read = 0;
        long leftToCopy = size; 
        while (leftToCopy > 0)
        { 
            if (leftToCopy < bufferSize) 
            {
                bufferSize = (int)leftToCopy; 
                buffer = new byte[bufferSize];
            }
            read = source.Read(buffer, 0, bufferSize);
            target.Write(buffer, 0, read); 
            leftToCopy -= read;
        } 
 
        // return the streams to thier orignal locations
        source.Position = originalSourcePosition; 
        target.Position = originalTargetPosition;

        Trace.SafeWrite(Trace.File, "Copied: {0} bytes.", target.Length);
    } 

#if DRT 
    ///  
    /// Compares two streams byte by byte.
    ///  
    /// The original stream
    /// The stream to compare with.
    internal static void CompareStream(Stream original, Stream comparee)
    { 
        original.Position = 0;
        comparee.Position = 0; 
        int data = 0; 
        int pos = 0;
        while (data != -1) 
        {
            data = original.ReadByte();
            pos++;
            Invariant.Assert(data == comparee.ReadByte(), 
                "Data mismatch at postion " + pos);
        } 
        if (pos - 1 == comparee.Length) 
        {
            Trace.SafeWrite(Trace.File, "Validate: {0} bytes.", comparee.Length); 
        }
    }
#endif
    #endregion Internal Methods 
}
} 

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
// Copyright (c) Microsoft Corporation. All rights reserved.

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