public LinkIndex Update(IList <LinkIndex> restrictions, IList <LinkIndex> substitution)
{
var sequence = restrictions.SkipFirst();
var newSequence = substitution.SkipFirst();
if (sequence.IsNullOrEmpty() && newSequence.IsNullOrEmpty())
{
return(Constants.Null);
}
if (sequence.IsNullOrEmpty())
{
return(Create(substitution));
}
if (newSequence.IsNullOrEmpty())
{
Delete(restrictions);
return(Constants.Null);
}
return(_sync.ExecuteWriteOperation((Func <ulong>)(() =>
{
ILinksExtensions.EnsureLinkIsAnyOrExists <ulong>(Links, (IList <ulong>)sequence);
Links.EnsureLinkExists(newSequence);
return UpdateCore(sequence, newSequence);
})));
}
