BeagleClient/Versioned.cs

   1 //
   2 // Versioned.cs
   3 //
   4 // Copyright (C) 2004 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
  28 using System;
  29 using System.Xml.Serialization;
  30
  31 namespace Beagle {
  32
  33         public class Versioned {
  34
  35                 protected DateTime timestamp = new DateTime (0);
  36
  37                 public bool ValidTimestamp {
  38                         get { return timestamp.Ticks > 0; }
  39                 }
  40
  41                 [XmlAttribute]
  42                 public DateTime Timestamp {
  43                         get { return timestamp; }
  44                         set { timestamp = value; }
  45                 }
  46
  47                 [XmlIgnore]
  48                 public double DaysSinceTimestamp {
  49                         get { return (DateTime.Now - timestamp).TotalDays; }
  50                 }
  51
  52                 public bool IsObsoletedBy (DateTime timestamp)
  53                 {
  54                         return !ValidTimestamp || Timestamp < timestamp;
  55                 }
  56
  57                 public bool IsObsoletedBy (Versioned other)
  58                 {
  59                         // We are never obsoleted by null.
  60                         if (other == null)
  61                                 return false;
  62
  63                         // Anything with a valid timestamp always is
  64                         // more recent than something w/o a timestamp.
  65                         if (ValidTimestamp || other.ValidTimestamp) {
  66                                 if (other.ValidTimestamp)
  67                                         return IsObsoletedBy (other.Timestamp);
  68                                 else
  69                                         return false;
  70                         }
  71
  72                         return false;
  73                 }
  74
  75                 public bool IsNewerThan (DateTime timestamp)
  76                 {
  77                         return ValidTimestamp && Timestamp > timestamp;
  78                 }
  79
  80                 public bool IsNewerThan (Versioned other)
  81                 {
  82                         // We are always newer than null.
  83                         if (other == null)
  84                                 return true;
  85
  86                         // Anything with a valid timestamp always is
  87                         // more recent than something w/o a timestamp.
  88                         if (ValidTimestamp || other.ValidTimestamp) {
  89                                 if (other.ValidTimestamp)
  90                                         return IsNewerThan (other.Timestamp);
  91                                 else
  92                                         return true;
  93                         }
  94
  95                         return false;
  96                 }
  97         }
  98 }