61 lines
2.6 KiB
C#
61 lines
2.6 KiB
C#
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//------------------------------------------------------------
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// Copyright (c) Microsoft Corporation. All rights reserved.
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//------------------------------------------------------------
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namespace System.ServiceModel.Dispatcher
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{
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using System;
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using System.Xml;
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using System.Xml.XPath;
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/// <summary>
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/// SeekableXPathNavigator extends XPathNavigator
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///
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/// The FilterEngine can work with SeekingXPathNavigator more efficiently than it can with
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/// the raw XPathNavigator.
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///
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/// A navigator is a cursor over an Xml document. While executing queries, the FE must take
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/// frequent snapshots of the Navigator/cursor's current position. The only way for it to do so
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/// is to Clone the navigator, which requires a memory allocation - something we wish to avoid.
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/// Therefore, we introduce a CurrentPosition property that gives us a very fast way to save
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/// and set where the navigator is placed in a document - without cloning.
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///
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/// </summary>
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public abstract class SeekableXPathNavigator : XPathNavigator
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{
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// An opaque position reference
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// An integer for efficiency
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public abstract long CurrentPosition
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{
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get;
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set;
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}
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/// <summary>
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/// Compare the two given navigator positions
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/// </summary>
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public abstract XmlNodeOrder ComparePosition(long firstPosition, long secondPosition);
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/// <summary>
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/// Return the local name of the node at the given position
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/// The localName is typically a node's tag - without the prefix
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/// </summary>
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public abstract string GetLocalName(long nodePosition);
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/// <summary>
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/// Return the Name of the node at the given position
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/// The Name is a node's tag and typically includes the prefix
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/// </summary>
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public abstract string GetName(long nodePosition);
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/// <summary>
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/// Return the namespace URI of the node at the given positon
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/// </summary>
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public abstract string GetNamespace(long nodePosition);
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/// <summary>
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/// What kind of node is this? - Element, Attribute, Processing Instruction etc
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/// </summary>
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public abstract XPathNodeType GetNodeType(long nodePosition);
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/// <summary>
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/// Return the string value of the node at the given position.
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/// For elements, this is InnerText - the concatenation of all Text nodes below the node at the specified position
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/// </summary>
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public abstract string GetValue(long nodePosition);
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}
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}
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