Files
Aaru/Aaru.Images/Virtual98/Read.cs

124 lines
4.7 KiB
C#

// /***************************************************************************
// Aaru Data Preservation Suite
// ----------------------------------------------------------------------------
//
// Filename : Read.cs
// Author(s) : Natalia Portillo <claunia@claunia.com>
//
// Component : Disk image plugins.
//
// --[ Description ] ----------------------------------------------------------
//
// Reads Virtual98 disk images.
//
// --[ 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 © 2011-2025 Natalia Portillo
// ****************************************************************************/
using System.IO;
using System.Linq;
using System.Text;
using Aaru.CommonTypes;
using Aaru.CommonTypes.Enums;
using Aaru.CommonTypes.Interfaces;
using Aaru.Helpers;
namespace Aaru.Images;
public sealed partial class Virtual98
{
#region IWritableImage Members
/// <inheritdoc />
public ErrorNumber Open(IFilter imageFilter)
{
Stream stream = imageFilter.GetDataForkStream();
stream.Seek(0, SeekOrigin.Begin);
// Even if comment is supposedly ASCII, I'm pretty sure most emulators allow Shift-JIS to be used :p
var shiftjis = Encoding.GetEncoding("shift_jis");
if(stream.Length < Marshal.SizeOf<Virtual98Header>()) return ErrorNumber.InvalidArgument;
var hdrB = new byte[Marshal.SizeOf<Virtual98Header>()];
stream.EnsureRead(hdrB, 0, hdrB.Length);
_v98Hdr = Marshal.ByteArrayToStructureLittleEndian<Virtual98Header>(hdrB);
_imageInfo.MediaType = MediaType.GENERIC_HDD;
_imageInfo.ImageSize = (ulong)(stream.Length - 0xDC);
_imageInfo.CreationTime = imageFilter.CreationTime;
_imageInfo.LastModificationTime = imageFilter.LastWriteTime;
_imageInfo.MediaTitle = Path.GetFileNameWithoutExtension(imageFilter.Filename);
_imageInfo.Sectors = _v98Hdr.totals;
_imageInfo.MetadataMediaType = MetadataMediaType.BlockMedia;
_imageInfo.SectorSize = _v98Hdr.sectorsize;
_imageInfo.Cylinders = _v98Hdr.cylinders;
_imageInfo.Heads = _v98Hdr.surfaces;
_imageInfo.SectorsPerTrack = _v98Hdr.sectors;
_imageInfo.Comments = StringHandlers.CToString(_v98Hdr.comment, shiftjis);
_nhdImageFilter = imageFilter;
return ErrorNumber.NoError;
}
/// <inheritdoc />
public ErrorNumber ReadSector(ulong sectorAddress, bool negative, out byte[] buffer, out SectorStatus sectorStatus)
{
sectorStatus = SectorStatus.Dumped;
return ReadSectors(sectorAddress, negative, 1, out buffer, out _);
}
/// <inheritdoc />
public ErrorNumber ReadSectors(ulong sectorAddress, bool negative, uint length, out byte[] buffer,
out SectorStatus[] sectorStatus)
{
buffer = null;
sectorStatus = new SectorStatus[length];
if(negative) return ErrorNumber.NotSupported;
if(sectorAddress > _imageInfo.Sectors - 1) return ErrorNumber.OutOfRange;
if(sectorAddress + length > _imageInfo.Sectors) return ErrorNumber.OutOfRange;
buffer = new byte[length * _imageInfo.SectorSize];
sectorStatus = Enumerable.Repeat(SectorStatus.Dumped, (int)length).ToArray();
Stream stream = _nhdImageFilter.GetDataForkStream();
// V98 are lazy allocated
if((long)(0xDC + sectorAddress * _imageInfo.SectorSize) >= stream.Length) return ErrorNumber.NoError;
stream.Seek((long)(0xDC + sectorAddress * _imageInfo.SectorSize), SeekOrigin.Begin);
var toRead = (int)(length * _imageInfo.SectorSize);
if(toRead + stream.Position > stream.Length) toRead = (int)(stream.Length - stream.Position);
stream.EnsureRead(buffer, 0, toRead);
return ErrorNumber.NoError;
}
#endregion
}