mcs/class/System.Core/System.Linq/Internal/ConcurrentLookup.cs

   1 #if NET_4_0
   2 //
   3 // ConcurrentLookup.cs
   4 //
   5 // Author:
   6 //       Jérémie "Garuma" Laval <jeremie.laval@gmail.com>
   7 //
   8 // Copyright (c) 2010 Jérémie "Garuma" Laval
   9 //
  10 // Permission is hereby granted, free of charge, to any person obtaining a copy
  11 // of this software and associated documentation files (the "Software"), to deal
  12 // in the Software without restriction, including without limitation the rights
  13 // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  14 // copies of the Software, and to permit persons to whom the Software is
  15 // furnished to do so, subject to the following conditions:
  16 //
  17 // The above copyright notice and this permission notice shall be included in
  18 // all copies or substantial portions of the Software.
  19 //
  20 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  21 // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  22 // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  23 // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  24 // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  25 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  26 // THE SOFTWARE.
  27
  28 using System;
  29 using System.Threading;
  30 using System.Collections;
  31 using System.Collections.Generic;
  32 using System.Collections.Concurrent;
  33
  34 namespace System.Linq
  35 {
  36         internal class ConcurrentLookup<TKey, TElement> : ILookup<TKey, TElement>
  37         {
  38                 ConcurrentDictionary<TKey, IEnumerable<TElement>> dictionary;
  39
  40                 private class AddSlot
  41                 {
  42                         TElement element;
  43
  44                         internal AddSlot (TElement element)
  45                         {
  46                                 this.element = element;
  47                         }
  48
  49                         internal IEnumerable<TElement> AddMethod (TKey key)
  50                         {
  51                                 List<TElement> list = new List<TElement> ();
  52                                 list.Add (element);
  53
  54                                 return list;
  55                         }
  56
  57                         internal IEnumerable<TElement> UpdateMethod (TKey key, IEnumerable<TElement> old)
  58                         {
  59                                 ICollection<TElement> coll = (ICollection<TElement>)old;
  60                                 coll.Add (element);
  61
  62                                 return coll;
  63                         }
  64                 }
  65
  66                 internal ConcurrentLookup (IEqualityComparer<TKey> comparer)
  67                 {
  68                         this.dictionary = new ConcurrentDictionary<TKey, IEnumerable<TElement>> (comparer);
  69                 }
  70
  71                 internal void Add (TKey key, TElement element)
  72                 {
  73                         AddSlot slot = new AddSlot (element);
  74                         dictionary.AddOrUpdate (key, slot.AddMethod, slot.UpdateMethod);
  75                 }
  76
  77                 public bool Contains (TKey key)
  78                 {
  79                         return dictionary.ContainsKey (key);
  80                 }
  81
  82                 public IEnumerable<TElement> this[TKey key] {
  83                         get {
  84                                 return dictionary[key];
  85                         }
  86                 }
  87
  88                 public int Count {
  89                         get {
  90                                 return dictionary.Count;
  91                         }
  92                 }
  93
  94                 public IList<TKey> Keys {
  95                         get {
  96                                 return (IList<TKey>)dictionary.Keys;
  97                         }
  98                 }
  99
 100                 IEnumerator IEnumerable.GetEnumerator ()
 101                 {
 102                         return (IEnumerator)GetEnumeratorInternal ();
 103                 }
 104
 105                 IEnumerator<IGrouping<TKey, TElement>> IEnumerable<IGrouping<TKey, TElement>>.GetEnumerator ()
 106                 {
 107                         return GetEnumeratorInternal ();
 108                 }
 109
 110                 IEnumerator<IGrouping<TKey, TElement>> GetEnumeratorInternal ()
 111                 {
 112                         return dictionary.Select ((pair) => new ConcurrentGrouping<TKey, TElement> (pair.Key, pair.Value)).GetEnumerator ();
 113                 }
 114         }
 115 }
 116
 117 #endif