public int ReadFrom(byte[] buffer, int offset)
{
if (!DescriptorTag.IsValid(buffer, offset))
{
throw new InvalidDataException("Invalid Anchor Volume Descriptor Pointer (invalid tag)");
}
Tag = new DescriptorTag();
Tag.ReadFrom(buffer, offset);
if (UdfUtilities.ComputeCrc(buffer, offset + Tag.Size, Tag.DescriptorCrcLength) != Tag.DescriptorCrc)
{
throw new InvalidDataException("Invalid Anchor Volume Descriptor Pointer (invalid CRC)");
}
return Parse(buffer, offset);
}
protected static List<ExtendedAttributeRecord> ReadExtendedAttributes(byte[] eaData)
{
if (eaData != null && eaData.Length != 0)
{
DescriptorTag eaTag = new DescriptorTag();
eaTag.ReadFrom(eaData, 0);
int implAttrLocation = Utilities.ToInt32LittleEndian(eaData, 16);
int appAttrLocation = Utilities.ToInt32LittleEndian(eaData, 20);
List<ExtendedAttributeRecord> extendedAttrs = new List<ExtendedAttributeRecord>();
int pos = 24;
while (pos < eaData.Length)
{
ExtendedAttributeRecord ea;
if (pos >= implAttrLocation)
{
ea = new ImplementationUseExtendedAttributeRecord();
}
else
{
ea = new ExtendedAttributeRecord();
}
int numRead = ea.ReadFrom(eaData, pos);
extendedAttrs.Add(ea);
pos += numRead;
}
return extendedAttrs;
}
else
{
return null;
}
}
public static bool TryFromStream(Stream stream, out DescriptorTag result)
{
byte[] next = Utilities.ReadFully(stream, 512);
if (!DescriptorTag.IsValid(next, 0))
{
result = null;
return false;
}
DescriptorTag dt = new DescriptorTag();
dt.ReadFrom(next, 0);
result = dt;
return true;
}
