/// <summary>
/// Create a Dragon tape block object.
/// Note that it is possible to create illegal blocks using this method by providing an unsupported block type or an invalid
/// checksum. Use the <see cref="Validate">Validate</see> method to verify that the block is actually valid.
/// For supported block types, the returned object will be of the appropriate type.
/// </summary>
/// <param name="blocktype">Block type idenfifier.</param>
/// <param name="data">Array containing the block payload data, or <value>null</value> for no payload.</param>
/// <param name="offset">Offset into the data array of first byte of block payload data.</param>
/// <param name="length">Size of the block payload data.</param>
/// <param name="checksum">Block checksum.</param>
/// <returns>Dragon tape block object.</returns>
public static DragonTapeBlock CreateBlock(DragonTapeBlockType blocktype, byte[] data, int offset, int length, int checksum)
{
DragonTapeBlock block = null;
switch (blocktype)
{
case DragonTapeBlockType.Header:
block = new DragonTapeHeaderBlock(data, offset, length, checksum);
break;
case DragonTapeBlockType.Data:
block = new DragonTapeDataBlock(data, offset, length, checksum);
break;
case DragonTapeBlockType.EndOfFile:
block = new DragonTapeEofBlock(data, offset, length, checksum);
break;
default:
block = new DragonTapeBlock(blocktype);
block.SetData(data, offset, length);
block.Checksum = checksum;
break;
}
return(block);
}
private void WriteDataBlocks(DragonFile file)
{
int blocks = (file.Length + 254) / 255; // number of data blocks to write
int offset = 0;
bool firstblock = true; // make sure to create a long leader for the first data block
for (int i = 0; i < blocks; i++)
{
var block = new DragonTapeDataBlock(file.GetData(), offset, Math.Min(255, file.Length - offset));
block.WriteBlock(Tape, !(firstblock || file.IsGapped));
offset += 255;
firstblock = false;
}
}