Org.Lwes/Emitter/EventEmitter.cs

   1 //
   2 // This file is part of the LWES .NET Binding (LWES.net)
   3 //
   4 // COPYRIGHT© 2009, Phillip Clark (phillip[at*flitbit[dot*org)
   5 //       original .NET implementation
   6 //
   7 // LWES.net is free software: you can redistribute it and/or modify
   8 // it under the terms of the Lesser GNU General Public License as published by
   9 // the Free Software Foundation, either version 3 of the License, or
  10 // (at your option) any later version.
  11 //
  12 // LWES.net is distributed in the hope that it will be useful,
  13 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 // Lesser GNU General Public License for more details.
  16 //
  17 // You should have received a copy of the Lesser GNU General Public License
  18 // along with LWES.net.  If not, see <http://www.gnu.org/licenses/>.
  19 //
  20 namespace Org.Lwes.Emitter
  21 {
  22         using System;
  23         using System.Net;
  24
  25         using Org.Lwes.Config;
  26         using Org.Lwes.DB;
  27         using System.Diagnostics;
  28         using Org.Lwes.Trace;
  29
  30         /// <summary>
  31         /// Utility class for accessing the default IEventEmitter implementation.
  32         /// </summary>
  33         /// <remarks>
  34         /// <para>If there is an ambient ServiceLocator present then this utility class will
  35         /// delegate to the ServiceLocator. The ServiceLocator should declare an instance
  36         /// of IEventEmitter with the name "eventEmitter".</para>
  37         /// <para>If an IoC container is not present, or if a service instance is not defined
  38         /// with the name "eventEmitter" then this utility will create a MulticastEventEmitter.</para>
  39         /// </remarks>
  40         public static class EventEmitter
  41         {
  42                 /// <summary>
  43                 /// Accesses the default instance of the IEventEmitter. Delegates to
  44                 /// an IoC container if present.
  45                 /// </summary>
  46                 public static IEventEmitter CreateDefault()
  47                 {
  48                         Traceable.TraceData(typeof(EventEmitter), TraceEventType.Verbose, "EventEmitter - creating default emitter");
  49
  50                         IEventEmitter result;
  51                         if (!IoCAdapter.TryCreateFromIoC<IEventEmitter>(Constants.DefaultEventEmitterContainerKey, out result))
  52                         { // Either there isn't a default event template defined in the IoC container
  53                                 // or there isn't an IoC container in use... fall back to configuration section.
  54                                 var def = LwesConfigurationSection.Current.DefaultEmitterName;
  55                                 result = CreateFromConfig(def);
  56                         }
  57                         if (result == null)
  58                         { // Not in IoC and not configured; fallback to programmatic default.
  59                                 result = CreateFallbackEmitter();
  60                         }
  61                         return result;
  62                 }
  63
  64                 /// <summary>
  65                 /// Creates an emitter from the configuration.
  66                 /// </summary>
  67                 /// <param name="name">name of the instance to create</param>
  68                 /// <returns>the named instance if it exists within the configuration;
  69                 /// otherwise null</returns>
  70                 /// <remarks>Note that two subsequent calls to this method will return
  71                 /// two separate instances of the configured instance.</remarks>
  72                 public static IEventEmitter CreateFromConfig(string name)
  73                 {
  74                         LwesConfigurationSection config = LwesConfigurationSection.Current;
  75                         if (config.Emitters == null) return null;
  76
  77                         EmitterConfigurationSection namedConfig = config.Emitters[name];
  78                         if (namedConfig == null)
  79                         {
  80                                 Traceable.TraceData(typeof(EventEmitter), TraceEventType.Verbose, () =>
  81                                 {
  82                                         return new object[] { String.Concat("EventEmitter - no configuration found for emitter: ", name) };
  83                                 });
  84                                 return null;
  85                         }
  86
  87                         Traceable.TraceData(typeof(EventEmitter), TraceEventType.Verbose, () =>
  88                         {
  89                                 return new object[] { String.Concat("EventEmitter - configuration found for emitter: ", name) };
  90                         });
  91                         if (namedConfig.UseMulticast)
  92                         {
  93                                 MulticastEventEmitter mee = new MulticastEventEmitter();
  94                                 mee.InitializeAll(namedConfig.Encoding, false, EventTemplateDB.CreateDefault(),
  95                                         IPAddress.Parse(namedConfig.AddressString), namedConfig.Port,
  96                                         namedConfig.MulticastTimeToLive, namedConfig.UseParallelEmit);
  97                                 return mee;
  98                         }
  99                         else
 100                         {
 101                                 throw new NotImplementedException("TODO: Support UnicastEventEmitter");
 102                                 //UnicastEventEmitter mee = new UnicastEventEmitter();
 103                                 //mee.Initialize(namedEmitterConfig.Encoding, false, EventTemplateDB.Default,
 104                                 //  IPAddress.Parse(namedEmitterConfig.AddressString), namedEmitterConfig.Port,
 105                                 //  namedEmitterConfig.MulticastTimeToLive, namedEmitterConfig.UseParallelEmit);
 106                                 //return mee;
 107                         }
 108                 }
 109
 110                 /// <summary>
 111                 /// Creates the named instance. If an IoC container is in use the IoC
 112                 /// container is consulted for the named instance first.
 113                 /// </summary>
 114                 /// <param name="name">name of the instance to create</param>
 115                 /// <returns>the named instance if it exists within the IoC container
 116                 /// or the configuration; otherwise null</returns>
 117                 public static IEventEmitter CreateNamedEmitter(string name)
 118                 {
 119                         IEventEmitter result;
 120                         if (!IoCAdapter.TryCreateFromIoC<IEventEmitter>(name, out result))
 121                         {
 122                                 Traceable.TraceData(typeof(EventEmitter), TraceEventType.Verbose, () =>
 123                                 {
 124                                         return new object[] { String.Concat("EventEmitter - IoC cannot resolve emitter: ", name) };
 125                                 });
 126                                 result = CreateFromConfig(name);
 127                         }
 128                         return result;
 129                 }
 130
 131                 private static IEventEmitter CreateFallbackEmitter()
 132                 {
 133                         Traceable.TraceData(typeof(EventEmitter), TraceEventType.Verbose, "EventEmitter - using fallback emitter");
 134
 135                         MulticastEventEmitter emitter = new MulticastEventEmitter();
 136                         emitter.InitializeAll(SupportedEncoding.Default
 137                                 , Constants.DefaultPerformValidation
 138                                 , EventTemplateDB.CreateDefault()
 139                                 , Constants.DefaultMulticastAddress
 140                                 , Constants.CDefaultMulticastPort
 141                                 , Constants.CDefaultMulticastTtl
 142                                 , true);
 143                         return emitter;
 144                 }
 145         }
 146 }