source: branches/eraser6/pluginsRewrite/Eraser.Manager/ErasureMethod.cs @ 2352

/* 
 * $Id$
 * Copyright 2008-2010 The Eraser Project
 * Original Author: Joel Low <lowjoel@users.sourceforge.net>
 * Modified By:
 * 
 * This file is part of Eraser.
 * 
 * Eraser is free software: you can redistribute it and/or modify it under the
 * terms of the GNU General Public License as published by the Free Software
 * Foundation, either version 3 of the License, or (at your option) any later
 * version.
 * 
 * Eraser is distributed in the hope that it will be useful, but WITHOUT ANY
 * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
 * A PARTICULAR PURPOSE. See the GNU General Public License for more details.
 * 
 * A copy of the GNU General Public License can be found at
 * <http://www.gnu.org/licenses/>.
 */

using System;
using System.Collections.Generic;
using System.Text;

using System.Reflection;
using System.IO;

using Eraser.Util;
using Eraser.Plugins;
using Eraser.Plugins.ExtensionPoints;

namespace Eraser.Manager
{
    /// <summary>
    /// Class managing all the erasure methods. This class pairs GUIDs with constructor
    /// prototypes, and when an instance of the erasure method is required, a new
    /// instance is created. This is unique to erasure methods since the other managers
    /// do not have run-time equivalents; they all are compile-time.
    /// </summary>
    public class ErasureMethodRegistrar : Registrar<ErasureMethod>
    {
        #region Default Erasure method
        private class DefaultMethod : ErasureMethod
        {
            public DefaultMethod()
            {
            }

            public override string Name
            {
                get { return S._("(default)"); }
            }

            public override int Passes
            {
                get { return 0; }
            }

            public override Guid Guid
            {
                get { return Guid.Empty; }
            }

            public override long CalculateEraseDataSize(ICollection<StreamInfo> paths, long targetSize)
            {
                throw new InvalidOperationException("The DefaultMethod class should never " +
                    "be used and should instead be replaced before execution!");
            }

            public override void Erase(Stream strm, long erasureLength, Prng prng,
                ErasureMethod.ErasureMethodProgressFunction callback)
            {
                throw new InvalidOperationException("The DefaultMethod class should never " +
                    "be used and should instead be replaced before execution!");
            }
        }

        /// <summary>
        /// A dummy method placeholder used for representing the default erase
        /// method. Do not use this variable when trying to call the erase function,
        /// this is just a placeholder and will throw a InvalidOperationException.
        /// </summary>
        [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Security", "CA2104:DoNotDeclareReadOnlyMutableReferenceTypes")]
        public static readonly ErasureMethod Default = new DefaultMethod();
        #endregion
    }

    public class ErasureMethodRegistrationEventArgs : EventArgs
    {
        /// <summary>
        /// Constructor.
        /// </summary>
        /// <param name="value">The GUID of the newly registered/unregistered
        /// erasure method.</param>
        public ErasureMethodRegistrationEventArgs(Guid value)
        {
            Guid = value;
        }

        /// <summary>
        /// The GUID of the newly registsered/unregistered erasure method.
        /// </summary>
        public Guid Guid { get; private set; }
    }
}