mcs/class/System.Threading.Tasks.Dataflow/System.Threading.Tasks.Dataflow/ChooserBlock.cs

   1 // JoinBlock.cs
   2 //
   3 // Copyright (c) 2011 Jérémie "garuma" Laval
   4 //
   5 // Permission is hereby granted, free of charge, to any person obtaining a copy
   6 // of this software and associated documentation files (the "Software"), to deal
   7 // in the Software without restriction, including without limitation the rights
   8 // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
   9 // copies of the Software, and to permit persons to whom the Software is
  10 // furnished to do so, subject to the following conditions:
  11 //
  12 // The above copyright notice and this permission notice shall be included in
  13 // all copies or substantial portions of the Software.
  14 //
  15 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  16 // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  17 // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  18 // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  19 // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  20 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  21 // THE SOFTWARE.
  22 //
  23 //
  24
  25
  26 using System;
  27 using System.Threading.Tasks;
  28 using System.Collections.Generic;
  29 using System.Collections.Concurrent;
  30
  31 namespace System.Threading.Tasks.Dataflow
  32 {
  33         internal class ChooserBlock<T1, T2, T3>
  34         {
  35                 class ChooseTarget<TMessage> : ITargetBlock<TMessage>
  36                 {
  37                         Action<TMessage> messageArrived;
  38
  39                         public ChooseTarget (Action<TMessage> messageArrived)
  40                         {
  41                                 this.messageArrived = messageArrived;
  42                         }
  43
  44                         public DataflowMessageStatus OfferMessage (DataflowMessageHeader messageHeader,
  45                                                                    TMessage messageValue,
  46                                                                    ISourceBlock<TMessage> source,
  47                                                                    bool consumeToAccept)
  48                         {
  49                                 messageArrived (messageValue);
  50                                 return DataflowMessageStatus.Accepted;
  51                         }
  52
  53                         public Task Completion {
  54                                 get {
  55                                         return null;
  56                                 }
  57                         }
  58
  59                         public void Complete ()
  60                         {
  61
  62                         }
  63
  64                         public void Fault (Exception ex)
  65                         {
  66
  67                         }
  68                 }
  69
  70                 TaskCompletionSource<int> completion = new TaskCompletionSource<int> ();
  71
  72                 public ChooserBlock (Action<T1> action1, Action<T2> action2, Action<T3> action3, DataflowBlockOptions dataflowBlockOptions)
  73                 {
  74                         // TODO: take care of options and its cancellation token
  75
  76                         Target1 = new ChooseTarget<T1> (message => MessageArrived (0, action1, message));
  77                         Target2 = new ChooseTarget<T2> (message => MessageArrived (1, action2, message));
  78                         Target3 = new ChooseTarget<T3> (message => MessageArrived (2, action3, message));
  79                 }
  80
  81                 void MessageArrived<TMessage> (int index, Action<TMessage> action, TMessage value)
  82                 {
  83                         try {
  84                                 action (value);
  85                                 completion.SetResult (index);
  86                         } catch (Exception e) {
  87                                 completion.SetException (e);
  88                         }
  89                 }
  90
  91                 public ITargetBlock<T1> Target1 {
  92                         get;
  93                         private set;
  94                 }
  95
  96                 public ITargetBlock<T2> Target2 {
  97                         get;
  98                         private set;
  99                 }
 100
 101                 public ITargetBlock<T3> Target3 {
 102                         get;
 103                         private set;
 104                 }
 105
 106                 public Task<int> Completion {
 107                         get {
 108                                 return completion.Task;
 109                         }
 110                 }
 111         }
 112 }
 113