Files
Aaru/Aaru.Images/Apridisk/Read.cs
Natalia Portillo 828c1e3da0 [Aaru.Images] Introduced constants for module names
Introduces constant fields for respective debug module names, replacing the hardcoded ones.
This is done to standardize the naming convention, reduce redundancy and potentially avoid any typos or name mismatches across the project.
This change makes the code more maintainable and easier to update in case module names need to be changed.
2023-10-03 18:50:20 +01:00

282 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.DiscImages;
public sealed partial class Apridisk
{
/// <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)
{
byte[] 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);
byte[] 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);
byte[] 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
uint[][] 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(int i = 0; i < totalCylinders; i++)
{
_sectorsData[i] = new byte[totalHeads][][];
spts[i] = new uint[totalHeads];
for(int 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)
{
byte[] 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);
byte[] 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;
}
}