Files
Aaru/DiscImageChef.DiscImages/QED/Read.cs

244 lines
11 KiB
C#
Raw Normal View History

// /***************************************************************************
// The Disc Image Chef
// ----------------------------------------------------------------------------
//
// Filename : Read.cs
// Author(s) : Natalia Portillo <claunia@claunia.com>
//
// Component : Disk image plugins.
//
// --[ Description ] ----------------------------------------------------------
//
// Reads Anex86 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 © 2011-2018 Natalia Portillo
// ****************************************************************************/
using System;
using System.Collections.Generic;
using System.IO;
using System.Runtime.InteropServices;
using DiscImageChef.CommonTypes;
using DiscImageChef.CommonTypes.Enums;
using DiscImageChef.CommonTypes.Interfaces;
using DiscImageChef.Console;
namespace DiscImageChef.DiscImages
{
public partial class Qed
{
public bool Open(IFilter imageFilter)
{
Stream stream = imageFilter.GetDataForkStream();
stream.Seek(0, SeekOrigin.Begin);
if(stream.Length < 512) return false;
byte[] qHdrB = new byte[64];
stream.Read(qHdrB, 0, 64);
qHdr = new QedHeader();
IntPtr headerPtr = Marshal.AllocHGlobal(64);
Marshal.Copy(qHdrB, 0, headerPtr, 64);
qHdr = (QedHeader)Marshal.PtrToStructure(headerPtr, typeof(QedHeader));
Marshal.FreeHGlobal(headerPtr);
DicConsole.DebugWriteLine("QED plugin", "qHdr.magic = 0x{0:X8}", qHdr.magic);
DicConsole.DebugWriteLine("QED plugin", "qHdr.cluster_size = {0}", qHdr.cluster_size);
DicConsole.DebugWriteLine("QED plugin", "qHdr.table_size = {0}", qHdr.table_size);
DicConsole.DebugWriteLine("QED plugin", "qHdr.header_size = {0}", qHdr.header_size);
DicConsole.DebugWriteLine("QED plugin", "qHdr.features = {0}", qHdr.features);
DicConsole.DebugWriteLine("QED plugin", "qHdr.compat_features = {0}", qHdr.compat_features);
DicConsole.DebugWriteLine("QED plugin", "qHdr.autoclear_features = {0}", qHdr.autoclear_features);
DicConsole.DebugWriteLine("QED plugin", "qHdr.l1_table_offset = {0}", qHdr.l1_table_offset);
DicConsole.DebugWriteLine("QED plugin", "qHdr.image_size = {0}", qHdr.image_size);
DicConsole.DebugWriteLine("QED plugin", "qHdr.backing_file_offset = {0}", qHdr.backing_file_offset);
DicConsole.DebugWriteLine("QED plugin", "qHdr.backing_file_size = {0}", qHdr.backing_file_size);
if(qHdr.image_size <= 1)
throw new ArgumentOutOfRangeException(nameof(qHdr.image_size), "Image size is too small");
if(!IsPowerOfTwo(qHdr.cluster_size))
throw new ArgumentOutOfRangeException(nameof(qHdr.cluster_size), "Cluster size must be a power of 2");
if(qHdr.cluster_size < 4096 || qHdr.cluster_size > 67108864)
throw new ArgumentOutOfRangeException(nameof(qHdr.cluster_size),
"Cluster size must be between 4 Kbytes and 64 Mbytes");
if(!IsPowerOfTwo(qHdr.table_size))
throw new ArgumentOutOfRangeException(nameof(qHdr.table_size), "Table size must be a power of 2");
if(qHdr.table_size < 1 || qHdr.table_size > 16)
throw new ArgumentOutOfRangeException(nameof(qHdr.table_size),
"Table size must be between 1 and 16 clusters");
if((qHdr.features & QED_FEATURE_MASK) > 0)
throw new ArgumentOutOfRangeException(nameof(qHdr.features),
$"Image uses unknown incompatible features {qHdr.features & QED_FEATURE_MASK:X}");
if((qHdr.features & QED_FEATURE_BACKING_FILE) == QED_FEATURE_BACKING_FILE)
throw new NotImplementedException("Differencing images not yet supported");
clusterSectors = qHdr.cluster_size / 512;
tableSize = qHdr.cluster_size * qHdr.table_size / 8;
DicConsole.DebugWriteLine("QED plugin", "qHdr.clusterSectors = {0}", clusterSectors);
DicConsole.DebugWriteLine("QED plugin", "qHdr.tableSize = {0}", tableSize);
byte[] l1TableB = new byte[tableSize * 8];
stream.Seek((long)qHdr.l1_table_offset, SeekOrigin.Begin);
stream.Read(l1TableB, 0, (int)tableSize * 8);
l1Table = new ulong[tableSize];
DicConsole.DebugWriteLine("QED plugin", "Reading L1 table");
for(long i = 0; i < l1Table.LongLength; i++) l1Table[i] = BitConverter.ToUInt64(l1TableB, (int)(i * 8));
l1Mask = 0;
int c = 0;
clusterBits = Ctz32(qHdr.cluster_size);
l2Mask = (tableSize - 1) << clusterBits;
l1Shift = clusterBits + Ctz32(tableSize);
for(int i = 0; i < 64; i++)
{
l1Mask <<= 1;
if(c >= 64 - l1Shift) continue;
l1Mask += 1;
c++;
}
sectorMask = 0;
for(int i = 0; i < clusterBits; i++) sectorMask = (sectorMask << 1) + 1;
DicConsole.DebugWriteLine("QED plugin", "qHdr.clusterBits = {0}", clusterBits);
DicConsole.DebugWriteLine("QED plugin", "qHdr.l1Mask = {0:X}", l1Mask);
DicConsole.DebugWriteLine("QED plugin", "qHdr.l1Shift = {0}", l1Shift);
DicConsole.DebugWriteLine("QED plugin", "qHdr.l2Mask = {0:X}", l2Mask);
DicConsole.DebugWriteLine("QED plugin", "qHdr.sectorMask = {0:X}", sectorMask);
maxL2TableCache = MAX_CACHE_SIZE / tableSize;
maxClusterCache = MAX_CACHE_SIZE / qHdr.cluster_size;
imageStream = stream;
sectorCache = new Dictionary<ulong, byte[]>();
l2TableCache = new Dictionary<ulong, ulong[]>();
clusterCache = new Dictionary<ulong, byte[]>();
imageInfo.CreationTime = imageFilter.GetCreationTime();
imageInfo.LastModificationTime = imageFilter.GetLastWriteTime();
imageInfo.MediaTitle = Path.GetFileNameWithoutExtension(imageFilter.GetFilename());
imageInfo.Sectors = qHdr.image_size / 512;
imageInfo.SectorSize = 512;
imageInfo.XmlMediaType = XmlMediaType.BlockMedia;
imageInfo.MediaType = MediaType.GENERIC_HDD;
imageInfo.ImageSize = qHdr.image_size;
imageInfo.Cylinders = (uint)(imageInfo.Sectors / 16 / 63);
imageInfo.Heads = 16;
imageInfo.SectorsPerTrack = 63;
return true;
}
public byte[] ReadSector(ulong sectorAddress)
{
if(sectorAddress > imageInfo.Sectors - 1)
throw new ArgumentOutOfRangeException(nameof(sectorAddress),
$"Sector address {sectorAddress} not found");
// Check cache
if(sectorCache.TryGetValue(sectorAddress, out byte[] sector)) return sector;
ulong byteAddress = sectorAddress * 512;
ulong l1Off = (byteAddress & l1Mask) >> l1Shift;
if((long)l1Off >= l1Table.LongLength)
throw new ArgumentOutOfRangeException(nameof(l1Off),
$"Trying to read past L1 table, position {l1Off} of a max {l1Table.LongLength}");
// TODO: Implement differential images
if(l1Table[l1Off] == 0) return new byte[512];
if(!l2TableCache.TryGetValue(l1Off, out ulong[] l2Table))
{
l2Table = new ulong[tableSize];
imageStream.Seek((long)l1Table[l1Off], SeekOrigin.Begin);
byte[] l2TableB = new byte[tableSize * 8];
imageStream.Read(l2TableB, 0, (int)tableSize * 8);
DicConsole.DebugWriteLine("QED plugin", "Reading L2 table #{0}", l1Off);
for(long i = 0; i < l2Table.LongLength; i++) l2Table[i] = BitConverter.ToUInt64(l2TableB, (int)(i * 8));
if(l2TableCache.Count >= maxL2TableCache) l2TableCache.Clear();
l2TableCache.Add(l1Off, l2Table);
}
ulong l2Off = (byteAddress & l2Mask) >> clusterBits;
ulong offset = l2Table[l2Off];
sector = new byte[512];
if(offset != 0 && offset != 1)
{
if(!clusterCache.TryGetValue(offset, out byte[] cluster))
{
cluster = new byte[qHdr.cluster_size];
imageStream.Seek((long)offset, SeekOrigin.Begin);
imageStream.Read(cluster, 0, (int)qHdr.cluster_size);
if(clusterCache.Count >= maxClusterCache) clusterCache.Clear();
clusterCache.Add(offset, cluster);
}
Array.Copy(cluster, (int)(byteAddress & sectorMask), sector, 0, 512);
}
if(sectorCache.Count >= MAX_CACHED_SECTORS) sectorCache.Clear();
sectorCache.Add(sectorAddress, sector);
return sector;
}
public byte[] ReadSectors(ulong sectorAddress, uint length)
{
if(sectorAddress > imageInfo.Sectors - 1)
throw new ArgumentOutOfRangeException(nameof(sectorAddress),
$"Sector address {sectorAddress} not found");
if(sectorAddress + length > imageInfo.Sectors)
throw new ArgumentOutOfRangeException(nameof(length), "Requested more sectors than available");
MemoryStream ms = new MemoryStream();
for(uint i = 0; i < length; i++)
{
byte[] sector = ReadSector(sectorAddress + i);
ms.Write(sector, 0, sector.Length);
}
return ms.ToArray();
}
}
}