Util/GuidFu.cs

   1 //
   2 // GuidFu.cs
   3 //
   4 // Copyright (C) 2005 Novell, Inc.
   5 //
   6
   7 //
   8 // Permission is hereby granted, free of charge, to any person obtaining a copy
   9 // of this software and associated documentation files (the "Software"), to deal
  10 // in the Software without restriction, including without limitation the rights
  11 // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  12 // copies of the Software, and to permit persons to whom the Software is
  13 // furnished to do so, subject to the following conditions:
  14 //
  15 // The above copyright notice and this permission notice shall be included in all
  16 // copies or substantial portions of the Software.
  17 //
  18 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  19 // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  20 // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  21 // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  22 // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  23 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  24 // SOFTWARE.
  25 //
  26
  27 using System;
  28
  29 namespace Beagle.Util {
  30
  31         public class GuidFu {
  32
  33                 public const string UriScheme = "uid";
  34
  35                 static private string UriPrefix = UriScheme + ":";
  36
  37                 static public string ToShortString (Guid uid)
  38                 {
  39                         // When converting 16 bytes to base64, the final two characters
  40                         // are always "==".
  41                         string str = Convert.ToBase64String (uid.ToByteArray (), 0, 16);
  42                         str = str.Substring (0, 22);
  43                         str = str.Replace ('/', '_'); // this avoids problems w/ Uris
  44                         return str;
  45                 }
  46
  47                 static public Guid FromShortString (string str)
  48                 {
  49                         // We need to add back the padding before converting the
  50                         // string back to a byte array.
  51                         str = str.Replace ('_', '/') + "==";
  52                         return new Guid (Convert.FromBase64String (str));
  53                 }
  54
  55                 static public Uri ToUri (Guid uid)
  56                 {
  57                         return new Uri (ToUriString (uid), true);
  58                 }
  59
  60                 static public Uri FromShortStringToUri (string str)
  61                 {
  62                         return new Uri (UriPrefix + str , true);
  63                 }
  64
  65                 static public Guid FromUri (Uri uri)
  66                 {
  67                         return FromShortString (uri.LocalPath);
  68                 }
  69
  70                 static public string ToUriString (Guid uid)
  71                 {
  72                         return UriPrefix + ToShortString (uid);
  73                 }
  74
  75                 static public Guid FromUriString (string str)
  76                 {
  77                         return FromShortString (str.Substring (UriPrefix.Length));
  78                 }
  79
  80         }
  81 }