XPathAncestorQuery.cs

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using System.Xml.XPath;
 
namespace MS.Internal.Xml.XPath;
 
internal sealed class XPathAncestorQuery : CacheAxisQuery
{
    private readonly bool _matchSelf;
 
    public override int CurrentPosition => outputBuffer.Count - count + 1;
 
    public override QueryProps Properties => base.Properties | QueryProps.Reverse;
 
    public XPathAncestorQuery(Query qyInput, string name, string prefix, XPathNodeType typeTest, bool matchSelf)
        : base(qyInput, name, prefix, typeTest)
    {
        _matchSelf = matchSelf;
    }
 
    private XPathAncestorQuery(XPathAncestorQuery other)
        : base(other)
    {
        _matchSelf = other._matchSelf;
    }
 
    public override object Evaluate(XPathNodeIterator context)
    {
        base.Evaluate(context);
        XPathNavigator xPathNavigator = null;
        XPathNavigator xPathNavigator2;
        while ((xPathNavigator2 = qyInput.Advance()) != null)
        {
            if (!_matchSelf || !matches(xPathNavigator2) || Query.Insert(outputBuffer, xPathNavigator2))
            {
                if (xPathNavigator == null || !xPathNavigator.MoveTo(xPathNavigator2))
                {
                    xPathNavigator = xPathNavigator2.Clone();
                }
                while (xPathNavigator.MoveToParent() && (!matches(xPathNavigator) || Query.Insert(outputBuffer, xPathNavigator)))
                {
                }
            }
        }
        return this;
    }
 
    public override XPathNodeIterator Clone()
    {
        return new XPathAncestorQuery(this);
    }
}