PathTable ReadPathTable(BasicVolumeDescriptor descriptor, Endian endian)
{
Assert.IsNotNull(descriptor, nameof(descriptor));
Assert.IsTrue(endian == Endian.BigEndian || endian == Endian.LittleEndian, "Endian must be set to either little or big.");
if (endian == Endian.BigEndian)
{
Reader.Position = descriptor.TypeMPathTableLocation * DefaultSectorSize;
}
else
{
Reader.Position = descriptor.TypeLPathTableLocation * DefaultSectorSize;
}
var buffer = Reader.ReadBytes((Int32)descriptor.PathTableSize);
var pathtable = new PathTable(endian);
for (var offset = 0; offset < buffer.Length;)
{
var namelength = buffer[offset + 0];
var extendedsectors = buffer[offset + 1];
var sector = BinaryIO.ReadUInt32FromBuffer(buffer, offset + 2, endian);
var parentindex = BinaryIO.ReadUInt16FromBuffer(buffer, offset + 6, endian);
var name = Encodings.ASCII.GetString(buffer, offset + 8, namelength).Trim(' ');
pathtable.Items.Add(new PathTableItem(name, sector, parentindex));
offset += MathUtil.RoundUp(8 + namelength, 2);
}
return(pathtable);
}
void WriteBasicVolumeDescriptor(BinaryWriter writer, BasicVolumeDescriptor descriptor)
{
Assert.IsNotNull(writer, nameof(writer));
Assert.IsNotNull(descriptor, nameof(descriptor));
var buffer = new Byte[DefaultSectorSize];
buffer[0] = (Byte)descriptor.VolumeDescriptorType;
BinaryIO.WriteIntoBuffer(buffer, 1, Encodings.ASCII, descriptor.StandardIdentifier, 5, ' ');
buffer[6] = descriptor.VolumeDescriptorVersion;
BinaryIO.WriteIntoBuffer(buffer, 8, Encodings.ASCII, descriptor.SystemIdentifier, 32, ' ');
BinaryIO.WriteIntoBuffer(buffer, 40, Encodings.ASCII, descriptor.VolumeIdentifier, 32, ' ');
BinaryIO.WriteIntoBuffer(buffer, 80, descriptor.VolumeSpaceSize, Endian.LittleEndian);
BinaryIO.WriteIntoBuffer(buffer, 84, descriptor.VolumeSpaceSize, Endian.BigEndian);
BinaryIO.WriteIntoBuffer(buffer, 120, descriptor.VolumeSetSize, Endian.LittleEndian);
BinaryIO.WriteIntoBuffer(buffer, 122, descriptor.VolumeSetSize, Endian.BigEndian);
BinaryIO.WriteIntoBuffer(buffer, 124, descriptor.VolumeSequenceNumber, Endian.LittleEndian);
BinaryIO.WriteIntoBuffer(buffer, 126, descriptor.VolumeSequenceNumber, Endian.BigEndian);
BinaryIO.WriteIntoBuffer(buffer, 128, descriptor.LogicalBlockSize, Endian.LittleEndian);
BinaryIO.WriteIntoBuffer(buffer, 130, descriptor.LogicalBlockSize, Endian.BigEndian);
BinaryIO.WriteIntoBuffer(buffer, 132, descriptor.PathTableSize, Endian.LittleEndian);
BinaryIO.WriteIntoBuffer(buffer, 136, descriptor.PathTableSize, Endian.BigEndian);
BinaryIO.WriteIntoBuffer(buffer, 140, descriptor.TypeLPathTableLocation, Endian.LittleEndian);
BinaryIO.WriteIntoBuffer(buffer, 144, descriptor.OptionalTypeLPathTableLocation, Endian.LittleEndian);
BinaryIO.WriteIntoBuffer(buffer, 148, descriptor.TypeMPathTableLocation, Endian.BigEndian);
BinaryIO.WriteIntoBuffer(buffer, 152, descriptor.OptionalTypeMPathTableLocation, Endian.BigEndian);
WriteDirectoryRecord(buffer, 156, descriptor.RootDirectory);
BinaryIO.WriteIntoBuffer(buffer, 190, Encodings.ASCII, descriptor.VolumeSetIdentifier, 128, ' ');
BinaryIO.WriteIntoBuffer(buffer, 318, Encodings.ASCII, descriptor.PublisherIdentifier, 128, ' ');
BinaryIO.WriteIntoBuffer(buffer, 446, Encodings.ASCII, descriptor.DataPreparerIdentifier, 128, ' ');
BinaryIO.WriteIntoBuffer(buffer, 574, Encodings.ASCII, descriptor.ApplicationIdentifier, 128, ' ');
BinaryIO.WriteIntoBuffer(buffer, 702, Encodings.ASCII, descriptor.CopyrightFileIdentifier, 37, ' ');
BinaryIO.WriteIntoBuffer(buffer, 739, Encodings.ASCII, descriptor.AbstractFileIdentifier, 37, ' ');
BinaryIO.WriteIntoBuffer(buffer, 776, Encodings.ASCII, descriptor.BibliographicFileIdentifier, 37, ' ');
WriteVolumeDescriptorDateTime(buffer, 813, descriptor.CreationDateAndTime);
WriteVolumeDescriptorDateTime(buffer, 830, descriptor.ModificationDateAndTime);
WriteVolumeDescriptorDateTime(buffer, 847, descriptor.ExpirationDateAndTime);
WriteVolumeDescriptorDateTime(buffer, 864, descriptor.EffectiveDateAndTime);
buffer[881] = descriptor.FileStructureVersion;
writer.Write(buffer);
}
/// <summary>
/// Reads the <see cref="VolumeDescriptor"/> at the current position of the image file.
/// </summary>
/// <returns>The <see cref="VolumeDescriptor"/> located at the current file position.</returns>
VolumeDescriptor ReadVolumeDescriptor()
{
var buffer = Reader.ReadBytes(DefaultSectorSize);
var type = (VolumeDescriptorType)buffer[0];
if (type == VolumeDescriptorType.Primary)
{
var descriptor = new BasicVolumeDescriptor();
descriptor.VolumeDescriptorType = type;
descriptor.StandardIdentifier = Encodings.ASCII.GetString(buffer, 1, 5);
descriptor.VolumeDescriptorVersion = buffer[6];
descriptor.SystemIdentifier = Encodings.ASCII.GetString(buffer, 8, 32).Trim(' ');
descriptor.VolumeIdentifier = Encodings.ASCII.GetString(buffer, 40, 32).Trim(' ');
descriptor.VolumeSpaceSize = BinaryIO.ReadUInt32FromBuffer(buffer, 80, Endian.LittleEndian);
descriptor.VolumeSetSize = BinaryIO.ReadUInt16FromBuffer(buffer, 120, Endian.LittleEndian);
descriptor.VolumeSequenceNumber = BinaryIO.ReadUInt16FromBuffer(buffer, 124, Endian.LittleEndian);
descriptor.LogicalBlockSize = BinaryIO.ReadUInt16FromBuffer(buffer, 128, Endian.LittleEndian);
descriptor.PathTableSize = BinaryIO.ReadUInt32FromBuffer(buffer, 132, Endian.LittleEndian);
descriptor.TypeLPathTableLocation = BinaryIO.ReadUInt32FromBuffer(buffer, 140, Endian.LittleEndian);
descriptor.OptionalTypeLPathTableLocation = BinaryIO.ReadUInt32FromBuffer(buffer, 144, Endian.LittleEndian);
descriptor.TypeMPathTableLocation = BinaryIO.ReadUInt32FromBuffer(buffer, 148, Endian.BigEndian);
descriptor.OptionalTypeMPathTableLocation = BinaryIO.ReadUInt32FromBuffer(buffer, 152, Endian.BigEndian);
descriptor.RootDirectory = ReadDirectoryRecord(buffer, 156);
descriptor.VolumeSetIdentifier = Encodings.ASCII.GetString(buffer, 190, 128).Trim(' ');
descriptor.PublisherIdentifier = Encodings.ASCII.GetString(buffer, 318, 128).Trim(' ');
descriptor.DataPreparerIdentifier = Encodings.ASCII.GetString(buffer, 446, 128).Trim(' ');
descriptor.ApplicationIdentifier = Encodings.ASCII.GetString(buffer, 574, 128).Trim(' ');
descriptor.CopyrightFileIdentifier = Encodings.ASCII.GetString(buffer, 702, 37).Trim(' ');
descriptor.AbstractFileIdentifier = Encodings.ASCII.GetString(buffer, 739, 37).Trim(' ');
descriptor.BibliographicFileIdentifier = Encodings.ASCII.GetString(buffer, 776, 37).Trim(' ');
descriptor.CreationDateAndTime = ReadVolumeDescriptorDateTime(buffer, 813);
descriptor.ModificationDateAndTime = ReadVolumeDescriptorDateTime(buffer, 830);
descriptor.ExpirationDateAndTime = ReadVolumeDescriptorDateTime(buffer, 847);
descriptor.EffectiveDateAndTime = ReadVolumeDescriptorDateTime(buffer, 864);
descriptor.FileStructureVersion = buffer[881];
return(descriptor);
}
if (type == VolumeDescriptorType.SetTerminator)
{
var descriptor = new SetTerminatorVolumeDescriptor();
descriptor.VolumeDescriptorType = type;
descriptor.StandardIdentifier = Encodings.ASCII.GetString(buffer, 1, 5);
descriptor.VolumeDescriptorVersion = buffer[6];
return(descriptor);
}
throw new Exception();
}
Dictionary <DirectoryRecord, List <DirectoryRecord> > ReadDirectoryRecords(BasicVolumeDescriptor descriptor)
{
Assert.IsNotNull(descriptor, nameof(descriptor));
var directorytree = new Dictionary <DirectoryRecord, List <DirectoryRecord> >();
var workinglist = new Stack <DirectoryRecord>();
workinglist.Push(descriptor.RootDirectory);
while (workinglist.Count > 0)
{
var dir = workinglist.Pop();
var children = ReadChildrenDirectoryRecords(dir);
var sectorobj = new DirectoryRecordSector();
sectorobj.Records.AddRange(children);
SectorMap[dir.SectorNumber] = sectorobj;
directorytree[dir] = new List <DirectoryRecord>();
foreach (var child in children.Skip(2))
{
if ((child.Flags & DirectoryRecordFlags.Directory) == DirectoryRecordFlags.Directory)
{
workinglist.Push(child);
}
else
{
SectorMap[child.SectorNumber] = new FileSector(child, () => FileSectorReadFunc((Int32)child.SectorNumber, (Int32)child.DataLength));
}
directorytree[dir].Add(child);
}
}
return(directorytree);
}
