//
// System.Xml.XmlIteratorNodeList
//
// Author:
// Atsushi Enomoto <atsushi@ximian.com>
//
// (C) 2006 Novell Inc.
//
//
// Permission is hereby granted, free of charge, to any person obtaining
// a copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to
// permit persons to whom the Software is furnished to do so, subject to
// the following conditions:
//
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
//
using System;
using System.Collections;
using System.Xml.XPath;
namespace System.Xml{
internal class XmlIteratorNodeList : XmlNodeList
{
XPathNodeIterator source;
XPathNodeIterator iterator;
ArrayList list;
bool finished;
#region Constructors
public XmlIteratorNodeList (XPathNodeIterator iter)
{
source = iter;
iterator = iter.Clone ();
list = new ArrayList ();
}
#endregion
#region Properties
public override int Count {
get {
/*
// The performance on Count depends on the
// iterator which is actually used. In some
// iterators, getting iterator.Count is much
// faster.
// With (current) implementation in general,
// those iterators that requires sorting is
// likely to have already-computed arrays, so
// for them getting Count does not impact on
// performance.
// But by default, getting iterator.Count means
// it internally iterates all the nodes. That
// might result in duplicate iteration (so
// ineffective). So here I decided that it
// just collects all the nodes to the list.
if (!finished) {
BaseIterator iter = iterator as BaseIterator;
if (iter != null && iter.ReverseAxis || iter is SlashIterator)
return iter.Count;
while (iterator.MoveNext ())
list.Add (((IHasXmlNode) iterator.Current).GetNode ());
finished = true;
}
return list.Count;
*/
// anyways such code that uses
// XmlNodeList.Count already gives up
// performance. Also, storing things in the
// list causes extra memory consumption.
return iterator.Count;
}
}
#endregion
#region Methods
public override IEnumerator GetEnumerator ()
{
if (finished)
return list.GetEnumerator ();
else
return new XPathNodeIteratorNodeListIterator (source);
// return new XPathNodeIteratorNodeListIterator2 (this);
}
public override XmlNode Item (int index)
{
if (index < 0)
return null;
if (index < list.Count)
return (XmlNode) list [index];
index++;
while (iterator.CurrentPosition < index) {
if (!iterator.MoveNext ()) {
finished = true;
return null;
}
list.Add (((IHasXmlNode) iterator.Current).GetNode ());
}
return (XmlNode) list [index - 1];
}
#endregion
class XPathNodeIteratorNodeListIterator : IEnumerator
{
XPathNodeIterator iter;
XPathNodeIterator source;
public XPathNodeIteratorNodeListIterator (XPathNodeIterator source)
{
this.source = source;
Reset ();
}
public bool MoveNext ()
{
return iter.MoveNext ();
}
public object Current {
get { return ((IHasXmlNode) iter.Current).GetNode (); }
}
public void Reset ()
{
iter = source.Clone ();
}
}
/*
class XPathNodeIteratorNodeListIterator2 : IEnumerator
{
int current = -1;
XmlIteratorNodeList source;
public XPathNodeIteratorNodeListIterator2 (XmlIteratorNodeList source)
{
this.source = source;
}
public bool MoveNext ()
{
return source [++current] != null;
}
public object Current {
get { return source [current]; }
}
public void Reset ()
{
current = -1;
}
}
*/
}
}
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