/// <summary>
/// predict the size of the frames on disk (without any padding)
/// by streaming the tag to a dummy stream, which updates the stored size.
/// </summary>
/// <remarks>
/// Although the the padding is streamed out,
/// the size isn't added on to Header.TagSize
/// </remarks>
public void UpdateSize()
{
if (!IsValid)
{
Header.TagSize = 0; // clear the TagSize stored in the tagModel
}
// TODO: there must be a better way of obtaining this!!
using (Stream stream = new MemoryStream())
{
FrameManager.Serialize(this, stream);
}
}
public int CalculateCrc()
{
if (!IsValid)
{
return(0);
}
using (MemoryStream stream = new MemoryStream())
{
// serialise tags to a buffer, without any padding
FrameManager.Serialize(this, stream);
// obtain whole buffer as byte array
byte[] buffer = stream.ToArray();
// calculate the size of the tag without the padding
int tagsize = (int)buffer.Length - (int)Header.PaddingSize;
// create and calculate crc-32 for the tag
ICSharpCode.SharpZipLib.Checksums.Crc32 crc = new ICSharpCode.SharpZipLib.Checksums.Crc32();
crc.Update(buffer, 0, tagsize);
return((int)crc.Value);
}
}
