nunit24/ClientUtilities/util/AssemblyWatcher.cs

   1 // ****************************************************************
   2 // This is free software licensed under the NUnit license. You
   3 // may obtain a copy of the license as well as information regarding
   4 // copyright ownership at http://nunit.org/?p=license&r=2.4.
   5 // ****************************************************************
   6
   7 using System;
   8 using System.IO;
   9 using System.Text;
  10 using System.Timers;
  11 using System.Collections;
  12
  13 namespace NUnit.Util
  14 {
  15         /// <summary>
  16         /// AssemblyWatcher keeps track of one or more assemblies to
  17         /// see if they have changed. It incorporates a delayed notification
  18         /// and uses a standard event to notify any interested parties
  19         /// about the change. The path to the assembly is provided as
  20         /// an argument to the event handler so that one routine can
  21         /// be used to handle events from multiple watchers.
  22         /// </summary>
  23         public class AssemblyWatcher
  24         {
  25                 FileSystemWatcher[] fileWatcher;
  26                 FileInfo[] fileInfo;
  27
  28                 protected System.Timers.Timer timer;
  29                 protected string changedAssemblyPath;
  30
  31                 public delegate void AssemblyChangedHandler(String fullPath);
  32                 public event AssemblyChangedHandler AssemblyChangedEvent;
  33
  34                 public AssemblyWatcher( int delay, string assemblyFileName )
  35                         : this( delay, new string[]{ assemblyFileName } ) { }
  36
  37                 public AssemblyWatcher( int delay, IList assemblies )
  38                 {
  39                         fileInfo = new FileInfo[assemblies.Count];
  40                         fileWatcher = new FileSystemWatcher[assemblies.Count];
  41
  42                         for( int i = 0; i < assemblies.Count; i++ )
  43                         {
  44                                 fileInfo[i] = new FileInfo( (string)assemblies[i] );
  45
  46                                 fileWatcher[i] = new FileSystemWatcher();
  47                                 fileWatcher[i].Path = fileInfo[i].DirectoryName;
  48                                 fileWatcher[i].Filter = fileInfo[i].Name;
  49                                 fileWatcher[i].NotifyFilter = NotifyFilters.Size | NotifyFilters.LastWrite;
  50                                 fileWatcher[i].Changed+=new FileSystemEventHandler(OnChanged);
  51                                 fileWatcher[i].EnableRaisingEvents = false;
  52                         }
  53
  54                         timer = new System.Timers.Timer( delay );
  55                         timer.AutoReset=false;
  56                         timer.Enabled=false;
  57                         timer.Elapsed+=new ElapsedEventHandler(OnTimer);
  58                 }
  59
  60                 public FileInfo GetFileInfo( int index )
  61                 {
  62                         return fileInfo[index];
  63                 }
  64
  65                 public void Start()
  66                 {
  67                         EnableWatchers( true );
  68                 }
  69
  70                 public void Stop()
  71                 {
  72                         EnableWatchers( false );
  73                 }
  74
  75                 private void EnableWatchers( bool enable )
  76                 {
  77                         foreach( FileSystemWatcher watcher in fileWatcher )
  78                                 watcher.EnableRaisingEvents = enable;
  79                 }
  80
  81                 protected void OnTimer(Object source, ElapsedEventArgs e)
  82                 {
  83                         lock(this)
  84                         {
  85                                 PublishEvent();
  86                                 timer.Enabled=false;
  87                         }
  88                 }
  89
  90                 protected void OnChanged(object source, FileSystemEventArgs e)
  91                 {
  92                         changedAssemblyPath = e.FullPath;
  93                         if ( timer != null )
  94                         {
  95                                 lock(this)
  96                                 {
  97                                         if(!timer.Enabled)
  98                                                 timer.Enabled=true;
  99                                         timer.Start();
 100                                 }
 101                         }
 102                         else
 103                         {
 104                                 PublishEvent();
 105                         }
 106                 }
 107
 108                 protected void PublishEvent()
 109                 {
 110                         if ( AssemblyChangedEvent != null )
 111                                 AssemblyChangedEvent( changedAssemblyPath );
 112                 }
 113         }
 114 }