BindStream.cs source code in C# .NET

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Code:

/ Dotnetfx_Vista_SP2 / Dotnetfx_Vista_SP2 / 8.0.50727.4016 / DEVDIV / depot / DevDiv / releases / Orcas / QFE / wpf / src / Framework / MS / Internal / Navigation / BindStream.cs / 1 / BindStream.cs

                            //---------------------------------------------------------------------------- 
//
// File: BindStream.cs
//
// Description: 
// Implements a monitored stream so that all calls to the base stream
// can be intersected and thereby loading progress can be accurately measured. 
// 
// Copyright (C) 2002 by Microsoft Corporation.  All rights reserved.
// 
//---------------------------------------------------------------------------

using System;
using System.IO; 
using System.Runtime.Remoting;
using System.Security; // SecurityCritical attribute 
using System.Security.Permissions; 
using MS.Internal.AppModel;
using System.Net; 
using System.Windows.Threading; //DispatcherObject
using System.Windows.Markup;
using System.Reflection;
 
namespace MS.Internal.Navigation
{ 
    #region BindStream Class 

    // Implements a monitored stream so that all calls to the base stream 
    // can be intersected and thereby loading progress can be accurately measured.
    internal class BindStream : Stream, IStreamInfo
    {
        #region Constructors 

        internal BindStream(Stream stream, long maxBytes, 
                            Uri uri, IContentContainer cc, Dispatcher callbackDispatcher) 
        {
            _bytesRead = 0; 
            _maxBytes = maxBytes;
            _lastProgressEventByte = 0;
            _stream = stream;
            _uri = uri; 
            _cc = cc;
            _callbackDispatcher = callbackDispatcher; 
        } 

        #endregion Constructors 

        #region Private Methods

        private void UpdateNavigationProgress() 
        {
            for(long numBytes =_lastProgressEventByte + _bytesInterval; 
                numBytes <= _bytesRead; 
                numBytes += _bytesInterval)
            { 
                UpdateNavProgressHelper(numBytes);
                _lastProgressEventByte = numBytes;
            }
 
            if (_bytesRead == _maxBytes && _lastProgressEventByte < _maxBytes)
            { 
                UpdateNavProgressHelper(_maxBytes); 
                _lastProgressEventByte = _maxBytes;
            } 
        }

        private void UpdateNavProgressHelper(long numBytes)
        { 
            if ((_callbackDispatcher != null) && (_callbackDispatcher.CheckAccess() != true))
            { 
                _callbackDispatcher.BeginInvoke( 
                                DispatcherPriority.Send,
                                (DispatcherOperationCallback)delegate(object unused) 
                                {
                                    _cc.OnNavigationProgress(_uri, numBytes, _maxBytes);
                                    return null;
                                }, 
                                null);
            } 
            else 
            {
                _cc.OnNavigationProgress(_uri, numBytes, _maxBytes); 
            }
        }

        #endregion Private Methods 

        #region Overrides 
 
        #region Overridden Properties
 
        /// 
        /// Overridden CanRead Property
        /// 
        public override bool CanRead 
        {
            get 
            { 
                return _stream.CanRead;
            } 
        }

        /// 
        /// Overridden CanSeek Property 
        /// 
        public override bool CanSeek 
        { 
            get
            { 
                return _stream.CanSeek;
            }
        }
 
        /// 
        /// Overridden CanWrite Property 
        ///  
        public override bool CanWrite
        { 
            get
            {
                return _stream.CanWrite;
            } 
        }
 
        ///  
        /// Overridden Length Property
        ///  
        public override long Length
        {
            get
            { 
                return _stream.Length;
            } 
        } 

        ///  
        /// Overridden Position Property
        /// 
        public override long Position
        { 
            get
            { 
                return _stream.Position; 
            }
            set 
            {
                _stream.Position = value;
            }
        } 

        #endregion Overridden Properties 
 
        #region Overridden Public Methods
 
        /// 
        /// Overridden BeginRead method
        /// 
        ///  
        /// 
        ///  
        ///  
        /// 
        ///  
        public override IAsyncResult BeginRead(
            byte[] buffer,
            int offset,
            int count, 
            AsyncCallback callback,
            object state 
            ) 
        {
            return _stream.BeginRead(buffer, offset, count, callback, state); 
        }

        /// 
        /// Overridden BeginWrite method 
        /// 
        ///  
        ///  
        /// 
        ///  
        /// 
        /// 
        public override IAsyncResult BeginWrite(
            byte[] buffer, 
            int offset,
            int count, 
            AsyncCallback callback, 
            object state
            ) 
        {
            return _stream.BeginWrite(buffer, offset, count, callback, state);
        }
 
        /// 
        /// Overridden Close method 
        ///  
        public override void Close()
        { 
            _stream.Close();

            // if current dispatcher is not the same as the dispatcher we should call back on,
            // post to the call back dispatcher. 
            if ((_callbackDispatcher != null) && (_callbackDispatcher.CheckAccess() != true))
            { 
                _callbackDispatcher.BeginInvoke( 
                                DispatcherPriority.Send,
                                (DispatcherOperationCallback)delegate(object unused) 
                                {
                                    _cc.OnStreamClosed();
                                    return null;
                                }, 
                                null);
            } 
            else 
            {
                _cc.OnStreamClosed(); 
            }
        }

        ///  
        /// Overridden CreateObjRef method
        ///  
        ///  
        /// 
        /// 
        ///     Critical: calls MarshalByRefObject.CreateObjRef which LinkDemands
        ///
        [SecurityCritical]
        public override ObjRef CreateObjRef( 
            Type requestedType
            ) 
        { 
            return _stream.CreateObjRef(requestedType);
        } 

        /// 
        /// Overridden EndRead method
        ///  
        /// 
        ///  
        public override int EndRead( 
            IAsyncResult asyncResult
            ) 
        {
            return _stream.EndRead(asyncResult);
        }
 
        /// 
        /// Overridden EndWrite method 
        ///  
        /// 
        public override void EndWrite( 
            IAsyncResult asyncResult
            )
        {
            _stream.EndWrite(asyncResult); 
        }
 
        ///  
        /// Overridden Equals method
        ///  
        /// 
        /// 
        public override bool Equals(
            object obj 
            )
        { 
            return _stream.Equals(obj); 
        }
 
        /// 
        /// Overridden Flush method
        /// 
        public override void Flush() 
        {
            _stream.Flush(); 
        } 

        ///  
        /// Overridden GetHashCode method
        /// 
        /// 
        public override int GetHashCode() 
        {
            return _stream.GetHashCode(); 
        } 

        /*///  
        /// GetLifetimeService method
        /// 
        /// 
        // Do we want this method here? 
        public new object GetLifetimeService()
        { 
            return _stream.GetLifetimeService(); 
        }
 
        /// 
        /// GetType method
        /// 
        ///  
        // Do we want this method here?
        public new Type GetType() 
        { 
            return _stream.GetType();
        }*/ 

        /// 
        /// Overridden InitializeLifetimeService method
        ///  
        /// 
        /// 
        ///     Critical: calls MarshalByRefObject.InitializeLifetimeService which LinkDemands 
        ///
        [SecurityCritical] 
        public override object InitializeLifetimeService()
        {
            return _stream.InitializeLifetimeService();
        } 

        ///  
        /// Overridden Read method 
        /// 
        ///  
        /// 
        /// 
        /// 
        public override int Read( 
            byte[] buffer,
            int offset, 
            int count 
            )
        { 
            int bytes = _stream.Read(buffer, offset, count);
            _bytesRead += bytes;

            //File, http, stream resources all seem to pass in a valid maxbytes. 
            //Incase loading compressed container or asp files serving out content cause maxbytes
            //to be not known upfront or a webserver does not send a content length(does http spec mandate it), 
            //update the maxbytes dynamically here. Also if we reach the end of the download stream 
            //force a NavigationProgress event with the last set of bytes and the final maxbytes value
 
            _maxBytes = _bytesRead > _maxBytes ? _bytesRead : _maxBytes;

            //Make sure the final notification is sent incase _maxBytes falls below the interval boundary
            if (((_lastProgressEventByte + _bytesInterval) <= _bytesRead) || 
                bytes == 0)
            { 
                UpdateNavigationProgress(); 
            }
 
            return bytes;
        }

        ///  
        /// Overridden ReadByte method
        ///  
        ///  
        public override int ReadByte()
        { 
            int val = _stream.ReadByte();
            if (val != -1)
            {
                _bytesRead++; 
                _maxBytes = _bytesRead > _maxBytes ? _bytesRead : _maxBytes;
            } 
 
            //Make sure the final notification is sent incase _maxBytes falls below the interval boundary
            if (((_lastProgressEventByte + _bytesInterval) <= _bytesRead) || 
                val == -1)
            {
                UpdateNavigationProgress();
            } 

            return val; 
        } 

        ///  
        /// Overridden Seek method
        /// 
        /// 
        ///  
        /// 
        public override long Seek( 
            long offset, 
            SeekOrigin origin
            ) 
        {
            return _stream.Seek(offset, origin);
        }
 
        /// 
        /// Overridden SetLength method 
        ///  
        /// 
        public override void SetLength( 
            long value
            )
        {
            _stream.SetLength(value); 
        }
 
        ///  
        /// Overridden ToString method
        ///  
        /// 
        public override string ToString()
        {
            return _stream.ToString(); 
        }
 
        ///  
        /// Overridden Write method
        ///  
        /// 
        /// 
        /// 
        public override void Write( 
            byte[] buffer,
            int offset, 
            int count 
            )
        { 
            _stream.Write(buffer, offset, count);
        }

        ///  
        /// Overridden WriteByte method
        ///  
        ///  
        public override void WriteByte(
            byte value 
            )
        {
            _stream.WriteByte(value);
        } 

        #endregion Overridden Public Methods 
 
        #endregion Overrides
 
        #region Properties

        /// 
        /// Underlying Stream of BindStream 
        /// 
        public Stream Stream 
        { 
            get
            { 
                return _stream;
            }
        }
 
        //
        // Assembly which contains the stream data. 
        // 
        Assembly IStreamInfo.Assembly
        { 
            get
            {
                Assembly assembly = null;
                if (_stream != null) 
                {
                    IStreamInfo streamInfo = _stream as IStreamInfo; 
                    if (streamInfo != null) 
                    {
                        assembly = streamInfo.Assembly; 
                    }
                }

                return assembly; 
            }
        } 
 
        #endregion Properties
 
        #region Private Data

        long                    _bytesRead;
        long                    _maxBytes; 
        long                    _lastProgressEventByte;
        Stream                  _stream; 
        Uri                     _uri; 
        IContentContainer        _cc;
        Dispatcher              _callbackDispatcher; 
        private const long      _bytesInterval = 1024;

        #endregion Private Data
    } 

    #endregion BindStream Class 
} 

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
// Copyright (c) Microsoft Corporation. All rights reserved.
//---------------------------------------------------------------------------- 
//
// File: BindStream.cs
//
// Description: 
// Implements a monitored stream so that all calls to the base stream
// can be intersected and thereby loading progress can be accurately measured. 
// 
// Copyright (C) 2002 by Microsoft Corporation.  All rights reserved.
// 
//---------------------------------------------------------------------------

using System;
using System.IO; 
using System.Runtime.Remoting;
using System.Security; // SecurityCritical attribute 
using System.Security.Permissions; 
using MS.Internal.AppModel;
using System.Net; 
using System.Windows.Threading; //DispatcherObject
using System.Windows.Markup;
using System.Reflection;
 
namespace MS.Internal.Navigation
{ 
    #region BindStream Class 

    // Implements a monitored stream so that all calls to the base stream 
    // can be intersected and thereby loading progress can be accurately measured.
    internal class BindStream : Stream, IStreamInfo
    {
        #region Constructors 

        internal BindStream(Stream stream, long maxBytes, 
                            Uri uri, IContentContainer cc, Dispatcher callbackDispatcher) 
        {
            _bytesRead = 0; 
            _maxBytes = maxBytes;
            _lastProgressEventByte = 0;
            _stream = stream;
            _uri = uri; 
            _cc = cc;
            _callbackDispatcher = callbackDispatcher; 
        } 

        #endregion Constructors 

        #region Private Methods

        private void UpdateNavigationProgress() 
        {
            for(long numBytes =_lastProgressEventByte + _bytesInterval; 
                numBytes <= _bytesRead; 
                numBytes += _bytesInterval)
            { 
                UpdateNavProgressHelper(numBytes);
                _lastProgressEventByte = numBytes;
            }
 
            if (_bytesRead == _maxBytes && _lastProgressEventByte < _maxBytes)
            { 
                UpdateNavProgressHelper(_maxBytes); 
                _lastProgressEventByte = _maxBytes;
            } 
        }

        private void UpdateNavProgressHelper(long numBytes)
        { 
            if ((_callbackDispatcher != null) && (_callbackDispatcher.CheckAccess() != true))
            { 
                _callbackDispatcher.BeginInvoke( 
                                DispatcherPriority.Send,
                                (DispatcherOperationCallback)delegate(object unused) 
                                {
                                    _cc.OnNavigationProgress(_uri, numBytes, _maxBytes);
                                    return null;
                                }, 
                                null);
            } 
            else 
            {
                _cc.OnNavigationProgress(_uri, numBytes, _maxBytes); 
            }
        }

        #endregion Private Methods 

        #region Overrides 
 
        #region Overridden Properties
 
        /// 
        /// Overridden CanRead Property
        /// 
        public override bool CanRead 
        {
            get 
            { 
                return _stream.CanRead;
            } 
        }

        /// 
        /// Overridden CanSeek Property 
        /// 
        public override bool CanSeek 
        { 
            get
            { 
                return _stream.CanSeek;
            }
        }
 
        /// 
        /// Overridden CanWrite Property 
        ///  
        public override bool CanWrite
        { 
            get
            {
                return _stream.CanWrite;
            } 
        }
 
        ///  
        /// Overridden Length Property
        ///  
        public override long Length
        {
            get
            { 
                return _stream.Length;
            } 
        } 

        ///  
        /// Overridden Position Property
        /// 
        public override long Position
        { 
            get
            { 
                return _stream.Position; 
            }
            set 
            {
                _stream.Position = value;
            }
        } 

        #endregion Overridden Properties 
 
        #region Overridden Public Methods
 
        /// 
        /// Overridden BeginRead method
        /// 
        ///  
        /// 
        ///  
        ///  
        /// 
        ///  
        public override IAsyncResult BeginRead(
            byte[] buffer,
            int offset,
            int count, 
            AsyncCallback callback,
            object state 
            ) 
        {
            return _stream.BeginRead(buffer, offset, count, callback, state); 
        }

        /// 
        /// Overridden BeginWrite method 
        /// 
        ///  
        ///  
        /// 
        ///  
        /// 
        /// 
        public override IAsyncResult BeginWrite(
            byte[] buffer, 
            int offset,
            int count, 
            AsyncCallback callback, 
            object state
            ) 
        {
            return _stream.BeginWrite(buffer, offset, count, callback, state);
        }
 
        /// 
        /// Overridden Close method 
        ///  
        public override void Close()
        { 
            _stream.Close();

            // if current dispatcher is not the same as the dispatcher we should call back on,
            // post to the call back dispatcher. 
            if ((_callbackDispatcher != null) && (_callbackDispatcher.CheckAccess() != true))
            { 
                _callbackDispatcher.BeginInvoke( 
                                DispatcherPriority.Send,
                                (DispatcherOperationCallback)delegate(object unused) 
                                {
                                    _cc.OnStreamClosed();
                                    return null;
                                }, 
                                null);
            } 
            else 
            {
                _cc.OnStreamClosed(); 
            }
        }

        ///  
        /// Overridden CreateObjRef method
        ///  
        ///  
        /// 
        /// 
        ///     Critical: calls MarshalByRefObject.CreateObjRef which LinkDemands
        ///
        [SecurityCritical]
        public override ObjRef CreateObjRef( 
            Type requestedType
            ) 
        { 
            return _stream.CreateObjRef(requestedType);
        } 

        /// 
        /// Overridden EndRead method
        ///  
        /// 
        ///  
        public override int EndRead( 
            IAsyncResult asyncResult
            ) 
        {
            return _stream.EndRead(asyncResult);
        }
 
        /// 
        /// Overridden EndWrite method 
        ///  
        /// 
        public override void EndWrite( 
            IAsyncResult asyncResult
            )
        {
            _stream.EndWrite(asyncResult); 
        }
 
        ///  
        /// Overridden Equals method
        ///  
        /// 
        /// 
        public override bool Equals(
            object obj 
            )
        { 
            return _stream.Equals(obj); 
        }
 
        /// 
        /// Overridden Flush method
        /// 
        public override void Flush() 
        {
            _stream.Flush(); 
        } 

        ///  
        /// Overridden GetHashCode method
        /// 
        /// 
        public override int GetHashCode() 
        {
            return _stream.GetHashCode(); 
        } 

        /*///  
        /// GetLifetimeService method
        /// 
        /// 
        // Do we want this method here? 
        public new object GetLifetimeService()
        { 
            return _stream.GetLifetimeService(); 
        }
 
        /// 
        /// GetType method
        /// 
        ///  
        // Do we want this method here?
        public new Type GetType() 
        { 
            return _stream.GetType();
        }*/ 

        /// 
        /// Overridden InitializeLifetimeService method
        ///  
        /// 
        /// 
        ///     Critical: calls MarshalByRefObject.InitializeLifetimeService which LinkDemands 
        ///
        [SecurityCritical] 
        public override object InitializeLifetimeService()
        {
            return _stream.InitializeLifetimeService();
        } 

        ///  
        /// Overridden Read method 
        /// 
        ///  
        /// 
        /// 
        /// 
        public override int Read( 
            byte[] buffer,
            int offset, 
            int count 
            )
        { 
            int bytes = _stream.Read(buffer, offset, count);
            _bytesRead += bytes;

            //File, http, stream resources all seem to pass in a valid maxbytes. 
            //Incase loading compressed container or asp files serving out content cause maxbytes
            //to be not known upfront or a webserver does not send a content length(does http spec mandate it), 
            //update the maxbytes dynamically here. Also if we reach the end of the download stream 
            //force a NavigationProgress event with the last set of bytes and the final maxbytes value
 
            _maxBytes = _bytesRead > _maxBytes ? _bytesRead : _maxBytes;

            //Make sure the final notification is sent incase _maxBytes falls below the interval boundary
            if (((_lastProgressEventByte + _bytesInterval) <= _bytesRead) || 
                bytes == 0)
            { 
                UpdateNavigationProgress(); 
            }
 
            return bytes;
        }

        ///  
        /// Overridden ReadByte method
        ///  
        ///  
        public override int ReadByte()
        { 
            int val = _stream.ReadByte();
            if (val != -1)
            {
                _bytesRead++; 
                _maxBytes = _bytesRead > _maxBytes ? _bytesRead : _maxBytes;
            } 
 
            //Make sure the final notification is sent incase _maxBytes falls below the interval boundary
            if (((_lastProgressEventByte + _bytesInterval) <= _bytesRead) || 
                val == -1)
            {
                UpdateNavigationProgress();
            } 

            return val; 
        } 

        ///  
        /// Overridden Seek method
        /// 
        /// 
        ///  
        /// 
        public override long Seek( 
            long offset, 
            SeekOrigin origin
            ) 
        {
            return _stream.Seek(offset, origin);
        }
 
        /// 
        /// Overridden SetLength method 
        ///  
        /// 
        public override void SetLength( 
            long value
            )
        {
            _stream.SetLength(value); 
        }
 
        ///  
        /// Overridden ToString method
        ///  
        /// 
        public override string ToString()
        {
            return _stream.ToString(); 
        }
 
        ///  
        /// Overridden Write method
        ///  
        /// 
        /// 
        /// 
        public override void Write( 
            byte[] buffer,
            int offset, 
            int count 
            )
        { 
            _stream.Write(buffer, offset, count);
        }

        ///  
        /// Overridden WriteByte method
        ///  
        ///  
        public override void WriteByte(
            byte value 
            )
        {
            _stream.WriteByte(value);
        } 

        #endregion Overridden Public Methods 
 
        #endregion Overrides
 
        #region Properties

        /// 
        /// Underlying Stream of BindStream 
        /// 
        public Stream Stream 
        { 
            get
            { 
                return _stream;
            }
        }
 
        //
        // Assembly which contains the stream data. 
        // 
        Assembly IStreamInfo.Assembly
        { 
            get
            {
                Assembly assembly = null;
                if (_stream != null) 
                {
                    IStreamInfo streamInfo = _stream as IStreamInfo; 
                    if (streamInfo != null) 
                    {
                        assembly = streamInfo.Assembly; 
                    }
                }

                return assembly; 
            }
        } 
 
        #endregion Properties
 
        #region Private Data

        long                    _bytesRead;
        long                    _maxBytes; 
        long                    _lastProgressEventByte;
        Stream                  _stream; 
        Uri                     _uri; 
        IContentContainer        _cc;
        Dispatcher              _callbackDispatcher; 
        private const long      _bytesInterval = 1024;

        #endregion Private Data
    } 

    #endregion BindStream Class 
} 

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

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