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// ==++==
//
// Copyright (c) Microsoft Corporation. All rights reserved.
//
// ==--==
/*============================================================
**
** Class: CaseInsensitiveHashCodeProvider
**
** <OWNER>Microsoft</OWNER>
**
**
** Purpose: Designed to support hashtables which require
** case-insensitive behavior while still maintaining case,
** this provides an efficient mechanism for getting the
** hashcode of the string ignoring case.
**
**
============================================================*/
namespace System.Collections {
//This class does not contain members and does not need to be serializable
using System;
using System.Collections;
using System.Globalization;
using System.Diagnostics.Contracts;
[Serializable]
[Obsolete("Please use StringComparer instead.")]
[System.Runtime.InteropServices.ComVisible(true)]
public class CaseInsensitiveHashCodeProvider : IHashCodeProvider {
private TextInfo m_text;
private static volatile CaseInsensitiveHashCodeProvider m_InvariantCaseInsensitiveHashCodeProvider = null;
public CaseInsensitiveHashCodeProvider() {
m_text = CultureInfo.CurrentCulture.TextInfo;
}
public CaseInsensitiveHashCodeProvider(CultureInfo culture) {
if (culture==null) {
throw new ArgumentNullException("culture");
}
Contract.EndContractBlock();
m_text = culture.TextInfo;
}
public static CaseInsensitiveHashCodeProvider Default
{
get
{
Contract.Ensures(Contract.Result<CaseInsensitiveHashCodeProvider>() != null);
return new CaseInsensitiveHashCodeProvider(CultureInfo.CurrentCulture);
}
}
public static CaseInsensitiveHashCodeProvider DefaultInvariant
{
get
{
Contract.Ensures(Contract.Result<CaseInsensitiveHashCodeProvider>() != null);
if (m_InvariantCaseInsensitiveHashCodeProvider == null) {
m_InvariantCaseInsensitiveHashCodeProvider = new CaseInsensitiveHashCodeProvider(CultureInfo.InvariantCulture);
}
return m_InvariantCaseInsensitiveHashCodeProvider;
}
}
public int GetHashCode(Object obj) {
if (obj==null) {
throw new ArgumentNullException("obj");
}
Contract.EndContractBlock();
String s = obj as String;
if (s==null) {
return obj.GetHashCode();
}
return m_text.GetCaseInsensitiveHashCode(s);
}
}
}
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