/// <summary>
/// Gets an estimate of a <see cref="FileDataPart"/>.
/// </summary>
/// <param name="guid">The <see cref="Guid"/> that should be used in the size estimate.</param>
/// <param name="start">The start position that should be used in the size estimate.</param>
/// <param name="size">The size of the data that should be used in the size estimate.</param>
/// <returns>The estimated size, in bytes, of a serialized <see cref="FileDataPart"/>.</returns>
internal static int EstimatePartSize(Guid guid, long start, int size)
{
var part = new FileDataPart(guid, start, new byte[size]);
var bytes = ObjectPacker.Pack(part);
return(bytes.Length + PacketHeader.HeaderSize(bytes.Length));
}
/// <summary>
/// Gets the sizes of all the parts of the file at the given buffer size.
/// </summary>
/// <param name="bufferSize">The size of the buffer and amount of data to estimate with.</param>
/// <returns>
/// Returns an IEnumerable containing the sizes of all the different parts of the file - including the <see cref="FileData"/> header.
/// </returns>
internal IEnumerable <int> GetPartSizes(int bufferSize)
{
if (Info == null)
{
throw new NullReferenceException("File information not found.");
}
if (!Info.Exists)
{
throw new FileNotFoundException(Info.FullName);
}
var bytes = ObjectPacker.Pack(this);
yield return(bytes.Length + PacketHeader.HeaderSize(bytes.Length));
bufferSize -= MetaSize;
long fileSize = Info.Length;
long start = 0;
while (fileSize > 0)
{
if (fileSize > bufferSize)
{
yield return(EstimatePartSize(Guid, start, bufferSize));
fileSize -= bufferSize;
start += bufferSize;
}
else
{
yield return(EstimatePartSize(Guid, start, (int)fileSize));
fileSize = 0;
}
}
}