1 /*

     2 * Copyright (c) 2009 Nokia Corporation and/or its subsidiary(-ies). 

     3 * All rights reserved.

     4 * This component and the accompanying materials are made available

     5 * under the terms of "Eclipse Public License v1.0"

     6 * which accompanies this distribution, and is available

     7 * at the URL "http://www.eclipse.org/legal/epl-v10.html".

     8 *

     9 * Initial Contributors:

    10 * Nokia Corporation - initial contribution.

    11 *

    12 * Contributors:

    13 * 

    14 * Description:

    15 *

    16 */

    17 using System;

    18 using System.Collections.Generic;

    19 using System.Text;

    20 using System.IO;

    21 using SymbianUtils;

    22 using SymbianUtils.Streams;

    23 using SymbianImageLib.Common.Header;

    24 using SymbianStructuresLib.Compression.Common;

    25 

    26 namespace SymbianImageLib.Common.Streams

    27 {

    28     internal class SIStream : DisposableObject

    29     {

    30         #region Enumerations

    31         public enum TOwnershipType

    32         {

    33             EOwned = 0,

    34             EOwnedExternally

    35         }

    36         #endregion

    37 

    38         #region Constructors

    39         public SIStream()

    40             : this( null, TOwnershipType.EOwned )

    41         {

    42         }

    43 

    44         public SIStream( Stream aStream )

    45             : this( aStream, TOwnershipType.EOwned )

    46         {

    47         }

    48 

    49         public SIStream( Stream aStream, TOwnershipType aType )

    50         {

    51             SwitchStream( aStream, aType );

    52         }

    53         #endregion

    54 

    55         #region Framework API

    56         public virtual bool InRange( long aPosition )

    57         {

    58             bool ret = ( aPosition >= 0 && aPosition < this.Length );

    59             return ret;

    60         }

    61 

    62         public virtual void Seek( long aPosition, SeekOrigin aOrigin )

    63         {

    64             iStream.Seek( aPosition, aOrigin );

    65         }

    66 

    67         public virtual int Read( byte[] aBuffer, int aOffset, int aCount )

    68         {

    69             int ret = iStream.Read( aBuffer, aOffset, aCount );

    70             return ret;

    71         }

    72 

    73         public virtual void Write( byte[] aBuffer )

    74         {

    75             Write( aBuffer, 0, aBuffer.Length );

    76         }

    77 

    78         public virtual void Write( SIStream aFrom, int aCount )

    79         {

    80             Write( (Stream) aFrom, aCount );

    81         }

    82 

    83         public virtual void Write( Stream aFrom, int aCount )

    84         {

    85             byte[] temp = new byte[ aCount ];

    86             int ret = aFrom.Read( temp, 0, aCount );

    87             if ( ret != aCount )

    88             {

    89                 throw new Exception( "Unable to read required number of bytes from stream" );

    90             }

    91             Write( temp, 0, aCount );

    92         }

    93 

    94         public virtual void Write( byte[] aBuffer, int aOffset, int aCount )

    95         {

    96             iStream.Write( aBuffer, aOffset, aCount );

    97         }

    98         #endregion

    99 

   100         #region API

   101         public void SwitchStream( Stream aStream, TOwnershipType aType )

   102         {

   103             if ( iStream != null )

   104             {

   105                 if ( iOwnership == TOwnershipType.EOwned )

   106                 {

   107                     iStream.Dispose();

   108                     iStream = null;

   109                     iLength = 0;

   110                 }

   111             }

   112             //

   113             iStream = aStream;

   114             iOwnership = aType;

   115             //

   116             if ( iStream != null )

   117             {

   118                 // Cache this because calling it is very expensive.

   119                 iLength = iStream.Length;

   120             }

   121         }

   122 

   123         public void Close()

   124         {

   125             base.Dispose();

   126         }

   127 

   128         public void Seek( long aPosition )

   129         {

   130             Seek( aPosition, SeekOrigin.Begin );

   131         }

   132 

   133         public SymbianStreamReaderLE CreateReader()

   134         {

   135             return SymbianStreamReaderLE.New( iStream );

   136         }

   137 

   138         public SymbianStreamReaderLE CreateReader( SymbianStreamReaderLE.TCloseOperation aCloseOperation )

   139         {

   140             return SymbianStreamReaderLE.New( iStream, aCloseOperation );

   141         }

   142         #endregion

   143 

   144         #region Properties

   145         public long Length

   146         {

   147             get { return iLength; }

   148         }

   149         #endregion

   150 

   151         #region Operators

   152         public static explicit operator Stream( SIStream aStream )

   153         {

   154             return aStream.InternalStream;

   155         }

   156         #endregion

   157 

   158         #region Internal methods

   159         protected Stream InternalStream

   160         {

   161             get { return iStream; }

   162         }

   163         #endregion

   164 

   165         #region Data members

   166         private Stream iStream = null;

   167         private TOwnershipType iOwnership = TOwnershipType.EOwned;

   168         private long iLength = 0;

   169         #endregion

   170     }

   171 }