/// <summary>
/// Creates new StreamSegment
/// </summary>
/// <param name="stream"></param>
/// <param name="offset"></param>
/// <param name="count">-1 to make the segment from offset to the end of the stream</param>
/// <exception cref="ArgumentOutOfRangeException">wrong offset or count</exception>
/// <exception cref="ArgumentNullException">stream</exception>
/// <remarks>
/// It's optimalized for recursive StreamSegments:
/// StreamSegment(StreamSegment(s, 1, 9), 2, 3) will be the same as StreamSegment(s, 3, 3)
/// </remarks>
public StreamSegment(IDataStream stream, long offset = 0, long count = -1)
{
if (stream == null)
{
throw new ArgumentNullException("stream");
}
if (offset < 0)
{
offset = stream.Length + offset;
}
if (offset < 0 || offset > stream.Length)
{
throw new ArgumentOutOfRangeException("invalid offset");
}
if (count == -1)
{
count = stream.Length - offset;
}
if (count < 0 || offset + count > stream.Length)
{
throw new ArgumentOutOfRangeException("invalid count");
}
this.count = count;
// optimalization for recursive StreamSegments
if (stream.GetType() == typeof(StreamSegment))
{
var s = (StreamSegment)stream;
this.stream = s.Stream;
this.offset = s.Offset + offset;
}
else
{
this.stream = stream;
this.offset = offset;
}
}
