Aaru/DiscImageChef.DiscImages/DART/Identify.cs

// /***************************************************************************
// The Disc Image Chef
// ----------------------------------------------------------------------------
//
// Filename       : Identify.cs
// Author(s)      : Natalia Portillo <claunia@claunia.com>
//
// Component      : Disk image plugins.
//
// --[ Description ] ----------------------------------------------------------
//
//     Identifies Apple Disk Archival/Retrieval Tool format.
//
// --[ License ] --------------------------------------------------------------
//
//     This library is free software; you can redistribute it and/or modify
//     it under the terms of the GNU Lesser General Public License as
//     published by the Free Software Foundation; either version 2.1 of the
//     License, or (at your option) any later version.
//
//     This library 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
//     Lesser General Public License for more details.
//
//     You should have received a copy of the GNU Lesser General Public
//     License along with this library; if not, see <http://www.gnu.org/licenses/>.
//
// ----------------------------------------------------------------------------
// Copyright © 2011-2019 Natalia Portillo
// ****************************************************************************/

using System.IO;
using System.Runtime.InteropServices;
using DiscImageChef.CommonTypes.Interfaces;

namespace DiscImageChef.DiscImages
{
    public partial class Dart
    {
        public bool Identify(IFilter imageFilter)
        {
            Stream stream = imageFilter.GetDataForkStream();

            if(stream.Length < 84) return false;

            DartHeader header = new DartHeader();
            stream.Seek(0, SeekOrigin.Begin);
            byte[] headerB = new byte[Marshal.SizeOf(header)];

            stream.Read(headerB, 0, Marshal.SizeOf(header));
            header = Helpers.Marshal.ByteArrayToStructureBigEndian<DartHeader>(headerB);

            if(header.srcCmp > COMPRESS_NONE) return false;

            int expectedMaxSize = 84 + header.srcSize * 2 * 524;

            switch(header.srcType)
            {
                case DISK_MAC:
                    if(header.srcSize != SIZE_MAC_SS && header.srcSize != SIZE_MAC) return false;

                    break;
                case DISK_LISA:
                    if(header.srcSize != SIZE_LISA) return false;

                    break;
                case DISK_APPLE2:
                    if(header.srcSize != SIZE_APPLE2) return false;

                    break;
                case DISK_MAC_HD:
                    if(header.srcSize != SIZE_MAC_HD) return false;

                    expectedMaxSize += 64;
                    break;
                case DISK_DOS:
                    if(header.srcSize != SIZE_DOS) return false;

                    break;
                case DISK_DOS_HD:
                    if(header.srcSize != SIZE_DOS_HD) return false;

                    expectedMaxSize += 64;
                    break;
                default: return false;
            }

            return stream.Length <= expectedMaxSize;
        }
    }
}