115 lines
3.1 KiB
C#
115 lines
3.1 KiB
C#
//------------------------------------------------------------------------------
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// <copyright file="DoubleLinkList.cs" company="Microsoft">
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// Copyright (c) Microsoft Corporation. All rights reserved.
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// </copyright>
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//------------------------------------------------------------------------------
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/*
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* DoubleLinkList
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*
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* Copyright (c) 1998-1999, Microsoft Corporation
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*
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*/
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namespace System.Web.Util {
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using System.Text;
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using System.Runtime.Serialization.Formatters;
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internal class DoubleLinkList : DoubleLink {
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internal DoubleLinkList() {
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}
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internal bool IsEmpty() {
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return _next == this;
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}
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internal virtual void InsertHead(DoubleLink entry) {
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entry.InsertAfter(this);
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}
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internal virtual void InsertTail(DoubleLink entry) {
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entry.InsertBefore(this);
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}
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internal DoubleLinkListEnumerator GetEnumerator() {
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return new DoubleLinkListEnumerator(this);
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}
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#if DBG
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internal override void DebugValidate() {
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DoubleLink l1, l2;
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base.DebugValidate();
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/*
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* Detect loops by moving one pointer forward 2 for every 1
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* of the other.
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*/
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l1 = l2 = this;
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for (;;) {
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/* move l2 forward */
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l2 = l2._next;
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if (l2 == this)
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break;
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Debug.CheckValid(l2 != l1, "Invalid loop in list, first move.");
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l2.DebugValidate();
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/* move l2 forward again */
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l2 = l2._next;
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if (l2 == this)
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break;
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Debug.CheckValid(l2 != l1, "Invalid loop in list, second move.");
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l2.DebugValidate();
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/* move l1 forward */
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l1 = l1._next;
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}
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}
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internal override string DebugDescription(String indent) {
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string desc;
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DoubleLinkListEnumerator lenum;
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int c;
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StringBuilder sb;
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string i2 = indent + " ";
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if (IsEmpty()) {
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desc = indent + "DoubleLinkList is empty\n";
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}
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else {
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c = Length;
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sb = new StringBuilder(indent + "DoubleLinkList has " + c + " entries.\n");
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lenum = GetEnumerator();
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while (lenum.MoveNext()) {
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sb.Append(Debug.GetDescription(lenum.GetDoubleLink(), i2));
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}
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desc = sb.ToString();
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}
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return desc;
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}
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#endif
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internal int Length {
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get {
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DoubleLinkListEnumerator lenum;
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int c;
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Debug.Validate(this);
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c = 0;
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lenum = GetEnumerator();
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while (lenum.MoveNext()) {
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c++;
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}
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return c;
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}
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}
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}
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}
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