private void ReadExtentDescriptors(LongAllocationDescriptor lad, long filePos)
{
byte[] allocExtDescBin = UdfUtilities.ReadExtent(_context, lad);
ExtentAllocationDescriptor allocExtDesc = Utilities.ToStruct <ExtentAllocationDescriptor>(allocExtDescBin, 0);
int i = 0;
long extentLengths = 0;
var activeBuffer = allocExtDesc.AllocationDescriptors;
while (i < activeBuffer.Length)
{
LongAllocationDescriptor extentLongAllocationDescriptor = Utilities.ToStruct <LongAllocationDescriptor>(activeBuffer, i);
if (extentLongAllocationDescriptor.ExtentLength == 0)
{
break;
}
if (extentLongAllocationDescriptor.Flags == ShortAllocationFlags.RecordedAndAllocated)
{
CookedExtent newExtent = new CookedExtent
{
FileContentOffset = filePos + extentLengths,
Partition = extentLongAllocationDescriptor.ExtentLocation.Partition,
StartPos = extentLongAllocationDescriptor.ExtentLocation.LogicalBlock * (long)_blockSize,
Length = extentLongAllocationDescriptor.ExtentLength
};
_extents.Add(newExtent);
extentLengths += newExtent.Length;
}
else if (extentLongAllocationDescriptor.Flags == ShortAllocationFlags.NextExtentOfAllocationDescriptors)
{
ReadExtentDescriptors(extentLongAllocationDescriptor, filePos + extentLengths);
}
i += extentLongAllocationDescriptor.Size;
}
}
public static File FromDescriptor(UdfContext context, LongAllocationDescriptor icb)
{
LogicalPartition partition = context.LogicalPartitions[icb.ExtentLocation.Partition];
byte[] rootDirData = UdfUtilities.ReadExtent(context, icb);
DescriptorTag rootDirTag = EndianUtilities.ToStruct <DescriptorTag>(rootDirData, 0);
if (rootDirTag.TagIdentifier == TagIdentifier.ExtendedFileEntry)
{
ExtendedFileEntry fileEntry = EndianUtilities.ToStruct <ExtendedFileEntry>(rootDirData, 0);
if (fileEntry.InformationControlBlock.FileType == FileType.Directory)
{
return(new Directory(context, partition, fileEntry));
}
return(new File(context, partition, fileEntry, (uint)partition.LogicalBlockSize));
}
if (rootDirTag.TagIdentifier == TagIdentifier.FileEntry)
{
FileEntry fileEntry = EndianUtilities.ToStruct <FileEntry>(rootDirData, 0);
if (fileEntry.InformationControlBlock.FileType == FileType.Directory)
{
return(new Directory(context, partition, fileEntry));
}
return(new File(context, partition, fileEntry, (uint)partition.LogicalBlockSize));
}
throw new NotImplementedException("Only ExtendedFileEntries implemented");
}
private void Initialize()
{
Context = new UdfContext
{
PhysicalPartitions = new Dictionary <ushort, PhysicalPartition>(),
PhysicalSectorSize = (int)_sectorSize,
LogicalPartitions = new List <LogicalPartition>()
};
IBuffer dataBuffer = new StreamBuffer(_data, Ownership.None);
AnchorVolumeDescriptorPointer avdp = AnchorVolumeDescriptorPointer.FromStream(_data, 256, _sectorSize);
uint sector = avdp.MainDescriptorSequence.Location;
bool terminatorFound = false;
while (!terminatorFound)
{
_data.Position = sector * (long)_sectorSize;
DescriptorTag dt;
if (!DescriptorTag.TryFromStream(_data, out dt))
{
break;
}
switch (dt.TagIdentifier)
{
case TagIdentifier.PrimaryVolumeDescriptor:
_pvd = PrimaryVolumeDescriptor.FromStream(_data, sector, _sectorSize);
break;
case TagIdentifier.ImplementationUseVolumeDescriptor:
// Not used
break;
case TagIdentifier.PartitionDescriptor:
PartitionDescriptor pd = PartitionDescriptor.FromStream(_data, sector, _sectorSize);
if (Context.PhysicalPartitions.ContainsKey(pd.PartitionNumber))
{
throw new IOException("Duplicate partition number reading UDF Partition Descriptor");
}
Context.PhysicalPartitions[pd.PartitionNumber] = new PhysicalPartition(pd, dataBuffer,
_sectorSize);
break;
case TagIdentifier.LogicalVolumeDescriptor:
_lvd = LogicalVolumeDescriptor.FromStream(_data, sector, _sectorSize);
break;
case TagIdentifier.UnallocatedSpaceDescriptor:
// Not used for reading
break;
case TagIdentifier.TerminatingDescriptor:
terminatorFound = true;
break;
default:
break;
}
sector++;
}
// Convert logical partition descriptors into actual partition objects
for (int i = 0; i < _lvd.PartitionMaps.Length; ++i)
{
Context.LogicalPartitions.Add(LogicalPartition.FromDescriptor(Context, _lvd, i));
}
byte[] fsdBuffer = UdfUtilities.ReadExtent(Context, _lvd.FileSetDescriptorLocation);
if (DescriptorTag.IsValid(fsdBuffer, 0))
{
FileSetDescriptor fsd = Utilities.ToStruct <FileSetDescriptor>(fsdBuffer, 0);
RootDirectory = (Directory)File.FromDescriptor(Context, fsd.RootDirectoryIcb);
}
}
