/// <summary>
/// Detects if a stream contains a valid ISO file system.
/// </summary>
/// <param name="data">The stream to inspect</param>
/// <returns><c>true</c> if the stream contains an ISO file system, else false.</returns>
public static bool Detect(Stream data)
{
byte[] buffer = new byte[IsoUtilities.SectorSize];
if (data.Length < 0x8000 + IsoUtilities.SectorSize)
{
return(false);
}
data.Position = 0x8000;
int numRead = Utilities.ReadFully(data, buffer, 0, IsoUtilities.SectorSize);
if (numRead != IsoUtilities.SectorSize)
{
return(false);
}
BaseVolumeDescriptor bvd = new BaseVolumeDescriptor(buffer, 0);
return(bvd.StandardIdentifier == "CD001");
}
/// <summary>
/// Initializes a new instance of the VfsCDReader class.
/// </summary>
/// <param name="data">The stream to read the ISO image from.</param>
/// <param name="joliet">Whether to read Joliet extensions.</param>
/// <param name="hideVersions">Hides version numbers (e.g. ";1") from the end of files</param>
public VfsCDReader(Stream data, bool joliet, bool hideVersions)
: base(new DiscFileSystemOptions())
{
_data = data;
_hideVersions = hideVersions;
long vdpos = 0x8000; // Skip lead-in
byte[] buffer = new byte[IsoUtilities.SectorSize];
long pvdPos = 0;
long svdPos = 0;
BaseVolumeDescriptor bvd;
do
{
data.Position = vdpos;
int numRead = data.Read(buffer, 0, IsoUtilities.SectorSize);
if (numRead != IsoUtilities.SectorSize)
{
break;
}
bvd = new BaseVolumeDescriptor(buffer, 0);
switch (bvd.VolumeDescriptorType)
{
case VolumeDescriptorType.Boot:
_bootVolDesc = new BootVolumeDescriptor(buffer, 0);
if (_bootVolDesc.SystemId != BootVolumeDescriptor.ElToritoSystemIdentifier)
{
_bootVolDesc = null;
}
break;
case VolumeDescriptorType.Primary: // Primary Vol Descriptor
pvdPos = vdpos;
break;
case VolumeDescriptorType.Supplementary: // Supplementary Vol Descriptor
svdPos = vdpos;
break;
case VolumeDescriptorType.Partition: // Volume Partition Descriptor
break;
case VolumeDescriptorType.SetTerminator: // Volume Descriptor Set Terminator
break;
}
vdpos += IsoUtilities.SectorSize;
}while (bvd.VolumeDescriptorType != VolumeDescriptorType.SetTerminator);
CommonVolumeDescriptor volDesc;
if (joliet && svdPos != 0)
{
data.Position = svdPos;
data.Read(buffer, 0, IsoUtilities.SectorSize);
volDesc = new SupplementaryVolumeDescriptor(buffer, 0);
}
else
{
data.Position = pvdPos;
data.Read(buffer, 0, IsoUtilities.SectorSize);
volDesc = new PrimaryVolumeDescriptor(buffer, 0);
}
Context = new IsoContext {
VolumeDescriptor = volDesc, DataStream = _data
};
RootDirectory = new ReaderDirectory(Context, volDesc.RootDirectory);
}
