/// <summary>
/// Sets the size (in bytes) of this file. Because
/// <see cref="Write(long, MemoryStream)"/> to the file will grow
/// it automatically if needed, this method is mainly usefull for truncating
/// a file.
/// </summary>
/// <param name="length">the new length of the file in bytes</param>
/// <exception cref="ReadOnlyException">ReadOnlyException if this file is read-only</exception>
/// <exception cref="IOException">IOException on error updating the file size</exception>
public void SetLength(long length)
{
CheckWritable();
if (GetLength() == length)
{
return;
}
UpdateTimeStamps(true);
chain.SetSize(length);
entry.SetStartCluster(chain.GetStartCluster());
entry.SetLength(length);
}
internal override void ChangeSize(int entryCount)
{
if (entryCount == 0)
{
throw new Exception();
}
var size = entryCount * FatDirectoryEntry.SIZE;
if (size > MAX_SIZE)
{
throw new DirectoryFullException(
"directory would grow beyond " + MAX_SIZE + " bytes",
GetCapacity(), entryCount);
}
SizeChanged(Chain.SetSize(Math.Max(size, Chain.GetClusterSize())));
}