public TOCBlock(byte[] buffer)
{
if (buffer.Length > Length)
{
// Checksum only applies to the first 512 bytes (even when the sector size > 512 bytes)
buffer = ByteReader.ReadBytes(buffer, 0, 512);
}
Signature = ByteReader.ReadAnsiString(buffer, 0x00, 8);
uint checksum = BigEndianConverter.ToUInt32(buffer, 0x08);
UpdateSequenceNumber = BigEndianConverter.ToUInt64(buffer, 0x0C);
// 16 zeros
int offset = 0x24;
// If the first character is not null (0x00), then there is a region defined
while (buffer[offset] != 0)
{
TOCRegion region = new TOCRegion(buffer, offset);
Regions.Add(region);
offset += TOCRegion.Length;
}
BigEndianWriter.WriteUInt32(buffer, 0x08, (uint)0); // we exclude the checksum field from checksum calculations
m_isChecksumValid = (checksum == PrivateHeader.CalculateChecksum(buffer));
}
/// <summary>
/// TOC Block may need to be padded with zeros in order to fill an entire sector
/// </summary>
public byte[] GetBytes()
{
byte[] buffer = new byte[Length];
ByteWriter.WriteAnsiString(buffer, 0x00, Signature, 8);
// we'll write checksum later
BigEndianWriter.WriteUInt64(buffer, 0x0C, UpdateSequenceNumber);
int offset = 0x24;
foreach (TOCRegion region in Regions)
{
region.WriteBytes(buffer, offset);
offset += TOCRegion.Length;
}
uint checksum = PrivateHeader.CalculateChecksum(buffer);
BigEndianWriter.WriteUInt32(buffer, 0x08, checksum);
return(buffer);
}
