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                 static public string ToShortString (Guid uid)
  34                 {
  35                         // When converting 16 bytes to base64, the final two characters
  36                         // are always "==".
  37                         string str = Convert.ToBase64String (uid.ToByteArray (), 0, 16);
  38                         str = str.Substring (0, 22);
  39                         str = str.Replace ('/', '_'); // this avoids problems w/ Uris
  40                         return str;
  41                 }
  42
  43                 static public Guid FromShortString (string str)
  44                 {
  45                         // We need to add back the padding before converting the
  46                         // string back to a byte array.
  47                         str = str.Replace ('_', '/') + "==";
  48                         return new Guid (Convert.FromBase64String (str));
  49                 }
  50
  51                 static public Uri ToUri (Guid uid)
  52                 {
  53                         return new Uri ("uid:" + ToShortString (uid), true);
  54                 }
  55
  56                 static public Uri FromShortStringToUri (string str)
  57                 {
  58                         return new Uri ("uid:" + str, true);
  59                 }
  60
  61                 static public Guid FromUri (Uri uri)
  62                 {
  63                         return FromShortString (uri.LocalPath);
  64                 }
  65
  66         }
  67 }