Files
Aaru/Aaru.Images/Apridisk/Read.cs

284 lines
11 KiB
C#

// /***************************************************************************
// Aaru Data Preservation Suite
// ----------------------------------------------------------------------------
//
// Filename : Read.cs
// Author(s) : Natalia Portillo <claunia@claunia.com>
//
// Component : Disk image plugins.
//
// --[ Description ] ----------------------------------------------------------
//
// Reads Apridisk 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 © 2011-2023 Natalia Portillo
// ****************************************************************************/
using System.IO;
using Aaru.CommonTypes;
using Aaru.CommonTypes.Enums;
using Aaru.CommonTypes.Interfaces;
using Aaru.Console;
using Aaru.Helpers;
namespace Aaru.Images;
public sealed partial class Apridisk
{
#region IWritableImage Members
/// <inheritdoc />
public ErrorNumber Open(IFilter imageFilter)
{
Stream stream = imageFilter.GetDataForkStream();
stream.Seek(0, SeekOrigin.Begin);
// Skip signature
stream.Seek(_signature.Length, SeekOrigin.Begin);
int totalCylinders = -1;
int totalHeads = -1;
int maxSector = -1;
int recordSize = Marshal.SizeOf<Record>();
// Count cylinders
while(stream.Position < stream.Length)
{
var recB = new byte[recordSize];
stream.EnsureRead(recB, 0, recordSize);
Record record = Marshal.SpanToStructureLittleEndian<Record>(recB);
switch(record.type)
{
// Deleted record, just skip it
case RecordType.Deleted:
AaruConsole.DebugWriteLine(MODULE_NAME, Localization.Found_deleted_record_at_0, stream.Position);
stream.Seek(record.headerSize - recordSize + record.dataSize, SeekOrigin.Current);
break;
case RecordType.Comment:
AaruConsole.DebugWriteLine(MODULE_NAME, Localization.Found_comment_record_at_0, stream.Position);
stream.Seek(record.headerSize - recordSize, SeekOrigin.Current);
var commentB = new byte[record.dataSize];
stream.EnsureRead(commentB, 0, commentB.Length);
_imageInfo.Comments = StringHandlers.CToString(commentB);
AaruConsole.DebugWriteLine(MODULE_NAME, Localization.Comment_0, _imageInfo.Comments);
break;
case RecordType.Creator:
AaruConsole.DebugWriteLine(MODULE_NAME, Localization.Found_creator_record_at_0, stream.Position);
stream.Seek(record.headerSize - recordSize, SeekOrigin.Current);
var creatorB = new byte[record.dataSize];
stream.EnsureRead(creatorB, 0, creatorB.Length);
_imageInfo.Creator = StringHandlers.CToString(creatorB);
AaruConsole.DebugWriteLine(MODULE_NAME, Localization.Creator_0, _imageInfo.Creator);
break;
case RecordType.Sector:
if(record.compression != CompressType.Compressed && record.compression != CompressType.Uncompresed)
return ErrorNumber.NotSupported;
AaruConsole.DebugWriteLine(MODULE_NAME,
record.compression == CompressType.Compressed
? Localization.
Found_compressed_sector_record_at_0_for_cylinder_1_head_2_sector_3
: Localization.
Found_uncompressed_sector_record_at_0_for_cylinder_1_head_2_sector_3,
stream.Position, record.cylinder, record.head, record.sector);
if(record.cylinder > totalCylinders)
totalCylinders = record.cylinder;
if(record.head > totalHeads)
totalHeads = record.head;
if(record.sector > maxSector)
maxSector = record.sector;
stream.Seek(record.headerSize - recordSize + record.dataSize, SeekOrigin.Current);
break;
default:
return ErrorNumber.NotSupported;
}
}
totalCylinders++;
totalHeads++;
if(totalCylinders <= 0 || totalHeads <= 0)
return ErrorNumber.NotSupported;
_sectorsData = new byte[totalCylinders][][][];
// Total sectors per track
var spts = new uint[totalCylinders][];
_imageInfo.Cylinders = (ushort)totalCylinders;
_imageInfo.Heads = (byte)totalHeads;
AaruConsole.DebugWriteLine(MODULE_NAME,
Localization.Found_0_cylinders_and_1_heads_with_a_maximum_sector_number_of_2,
totalCylinders, totalHeads, maxSector);
// Create heads
for(var i = 0; i < totalCylinders; i++)
{
_sectorsData[i] = new byte[totalHeads][][];
spts[i] = new uint[totalHeads];
for(var j = 0; j < totalHeads; j++)
_sectorsData[i][j] = new byte[maxSector + 1][];
}
_imageInfo.SectorSize = uint.MaxValue;
ulong headerSizes = 0;
// Read sectors
stream.Seek(_signature.Length, SeekOrigin.Begin);
while(stream.Position < stream.Length)
{
var recB = new byte[recordSize];
stream.EnsureRead(recB, 0, recordSize);
Record record = Marshal.SpanToStructureLittleEndian<Record>(recB);
switch(record.type)
{
// Not sector record, just skip it
case RecordType.Deleted:
case RecordType.Comment:
case RecordType.Creator:
stream.Seek(record.headerSize - recordSize + record.dataSize, SeekOrigin.Current);
headerSizes += record.headerSize + record.dataSize;
break;
case RecordType.Sector:
stream.Seek(record.headerSize - recordSize, SeekOrigin.Current);
var data = new byte[record.dataSize];
stream.EnsureRead(data, 0, data.Length);
spts[record.cylinder][record.head]++;
uint realLength = record.dataSize;
if(record.compression == CompressType.Compressed)
realLength = Decompress(data, out _sectorsData[record.cylinder][record.head][record.sector]);
else
_sectorsData[record.cylinder][record.head][record.sector] = data;
if(realLength < _imageInfo.SectorSize)
_imageInfo.SectorSize = realLength;
headerSizes += record.headerSize + record.dataSize;
break;
}
}
AaruConsole.DebugWriteLine(MODULE_NAME, Localization.Found_a_minimum_of_0_bytes_per_sector,
_imageInfo.SectorSize);
// Count sectors per track
uint spt = uint.MaxValue;
for(ushort cyl = 0; cyl < _imageInfo.Cylinders; cyl++)
{
for(ushort head = 0; head < _imageInfo.Heads; head++)
{
if(spts[cyl][head] < spt)
spt = spts[cyl][head];
}
}
_imageInfo.SectorsPerTrack = spt;
AaruConsole.DebugWriteLine(MODULE_NAME, Localization.Found_a_minimum_of_0_sectors_per_track,
_imageInfo.SectorsPerTrack);
_imageInfo.MediaType = Geometry.GetMediaType(((ushort)_imageInfo.Cylinders, (byte)_imageInfo.Heads,
(ushort)_imageInfo.SectorsPerTrack, 512, MediaEncoding.MFM,
false));
_imageInfo.ImageSize = (ulong)stream.Length - headerSizes;
_imageInfo.CreationTime = imageFilter.CreationTime;
_imageInfo.LastModificationTime = imageFilter.LastWriteTime;
_imageInfo.MediaTitle = Path.GetFileNameWithoutExtension(imageFilter.Filename);
_imageInfo.Sectors = _imageInfo.Cylinders * _imageInfo.Heads * _imageInfo.SectorsPerTrack;
_imageInfo.MetadataMediaType = MetadataMediaType.BlockMedia;
return ErrorNumber.NoError;
}
/// <inheritdoc />
public ErrorNumber ReadSector(ulong sectorAddress, out byte[] buffer)
{
buffer = null;
(ushort cylinder, byte head, byte sector) = LbaToChs(sectorAddress);
if(cylinder >= _sectorsData.Length)
return ErrorNumber.SectorNotFound;
if(head >= _sectorsData[cylinder].Length)
return ErrorNumber.SectorNotFound;
if(sector > _sectorsData[cylinder][head].Length)
return ErrorNumber.SectorNotFound;
buffer = _sectorsData[cylinder][head][sector];
return ErrorNumber.NoError;
}
/// <inheritdoc />
public ErrorNumber ReadSectors(ulong sectorAddress, uint length, out byte[] buffer)
{
buffer = null;
if(sectorAddress > _imageInfo.Sectors - 1)
return ErrorNumber.OutOfRange;
if(sectorAddress + length > _imageInfo.Sectors)
return ErrorNumber.OutOfRange;
var ms = new MemoryStream();
for(uint i = 0; i < length; i++)
{
ErrorNumber errno = ReadSector(sectorAddress + i, out byte[] sector);
if(errno != ErrorNumber.NoError)
return errno;
ms.Write(sector, 0, sector.Length);
}
buffer = ms.ToArray();
return ErrorNumber.NoError;
}
#endregion
}