/// <summary>
/// Includes the specified span path in the specified span instance and returns the updated span instance.
/// If <paramref name="spanToIncludeIn"/> is null, a new span instance is constructed and returned that contains
/// the specified include path.
/// </summary>
/// <param name="spanToIncludeIn">The span instance to which the include path should be added. May be null</param>
/// <param name="pathToInclude">The include path to add</param>
/// <returns>A non-null span instance that contains the specified include path in addition to any paths ut already contained</returns>
internal static Span IncludeIn(Span spanToIncludeIn, string pathToInclude)
{
if (null == spanToIncludeIn)
{
spanToIncludeIn = new Span();
}
spanToIncludeIn.Include(pathToInclude);
return spanToIncludeIn;
}
/// <summary>
/// Returns a span instance that is the union of the two specified span instances.
/// If <paramref name="span1"/> and <paramref name="span2"/> are both <c>null</c>,
/// then <c>null</c> is returned.
/// If <paramref name="span1"/> or <paramref name="span2"/> is null, but the remaining argument is non-null,
/// then the non-null argument is returned.
/// If neither <paramref name="span1"/> nor <paramref name="span2"/> are null, a new span instance is returned
/// that contains the merged span paths from both.
/// </summary>
/// <param name="span1">The first span instance from which to include span paths; may be <c>null</c></param>
/// <param name="span2">The second span instance from which to include span paths; may be <c>null</c></param>
/// <returns>A span instance representing the union of the two arguments; may be <c>null</c> if both arguments are null</returns>
internal static Span CopyUnion(Span span1, Span span2)
{
if (null == span1)
{
return span2;
}
if (null == span2)
{
return span1;
}
var retSpan = span1.Clone();
foreach (var path in span2.SpanList)
{
retSpan.AddSpanPath(path);
}
return retSpan;
}
/// <summary>
/// Creates a new Span with the same SpanPaths as this Span
/// </summary>
/// <returns></returns>
internal Span Clone()
{
var newSpan = new Span();
newSpan.SpanList.AddRange(_spanList);
newSpan._cacheKey = _cacheKey;
return newSpan;
}