2 // System.Collections.CaseInsensitiveHashCodeProvider.cs
5 // Sergey Chaban (serge@wildwestsoftware.com)
6 // Andreas Nahr (ClassDevelopment@A-SoftTech.com)
7 // Sebastien Pouliot <sebastien@ximian.com>
9 // Copyright (C) 2004-2005 Novell, Inc (http://www.novell.com)
11 // Permission is hereby granted, free of charge, to any person obtaining
12 // a copy of this software and associated documentation files (the
13 // "Software"), to deal in the Software without restriction, including
14 // without limitation the rights to use, copy, modify, merge, publish,
15 // distribute, sublicense, and/or sell copies of the Software, and to
16 // permit persons to whom the Software is furnished to do so, subject to
17 // the following conditions:
19 // The above copyright notice and this permission notice shall be
20 // included in all copies or substantial portions of the Software.
22 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
23 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
24 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
25 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
26 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
27 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
28 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
31 using System.Globalization;
32 using System.Runtime.InteropServices;
34 namespace System.Collections
38 [Obsolete ("Please use StringComparer instead.")]
44 class CaseInsensitiveHashCodeProvider : IHashCodeProvider
46 static readonly CaseInsensitiveHashCodeProvider singletonInvariant = new CaseInsensitiveHashCodeProvider (
47 CultureInfo.InvariantCulture);
48 static CaseInsensitiveHashCodeProvider singleton;
49 static readonly object sync = new object ();
51 TextInfo m_text; // must match MS name for serialization
53 // Public instance constructor
54 public CaseInsensitiveHashCodeProvider ()
56 CultureInfo culture = CultureInfo.CurrentCulture;
57 if (!AreEqual (culture, CultureInfo.InvariantCulture))
58 m_text = CultureInfo.CurrentCulture.TextInfo;
61 public CaseInsensitiveHashCodeProvider (CultureInfo culture)
64 throw new ArgumentNullException ("culture");
65 if (!AreEqual (culture, CultureInfo.InvariantCulture))
66 m_text = culture.TextInfo;
70 // Public static properties
73 public static CaseInsensitiveHashCodeProvider Default {
75 // MS actually constructs a new instance on each call, for
76 // performance reasons we're only constructing a new instance
77 // if the CurrentCulture changes
79 if (singleton == null) {
80 singleton = new CaseInsensitiveHashCodeProvider ();
81 } else if (singleton.m_text == null) {
82 if (!AreEqual (CultureInfo.CurrentCulture, CultureInfo.InvariantCulture))
83 singleton = new CaseInsensitiveHashCodeProvider ();
84 } else if (!AreEqual (singleton.m_text, CultureInfo.CurrentCulture)) {
85 singleton = new CaseInsensitiveHashCodeProvider ();
92 static bool AreEqual (CultureInfo a, CultureInfo b)
95 return a.LCID == b.LCID;
97 return a.Name == b.Name;
101 static bool AreEqual (TextInfo info, CultureInfo culture)
104 return info.LCID == culture.LCID;
106 return info.CultureName == culture.Name;
111 static CaseInsensitiveHashCodeProvider DefaultInvariant {
113 return singletonInvariant;
121 public int GetHashCode (object obj)
124 throw new ArgumentNullException ("obj");
126 string str = obj as string;
129 return obj.GetHashCode ();
134 if ((m_text != null) && !AreEqual (m_text, CultureInfo.InvariantCulture)) {
135 str = m_text.ToLower (str);
136 for (int i = 0; i < str.Length; i++) {
141 for (int i = 0; i < str.Length; i++) {
142 c = Char.ToLower (str [i], CultureInfo.InvariantCulture);