mcs/class/System.Core/System.Linq.Parallel.QueryNodes/QueryJoinNode.cs

   1 //
   2 // QueryJoinNode.cs
   3 //
   4 // Author:
   5 //       Jérémie "Garuma" Laval <jeremie.laval@gmail.com>
   6 //
   7 // Copyright (c) 2010 Jérémie "Garuma" Laval
   8 //
   9 // Permission is hereby granted, free of charge, to any person obtaining a copy
  10 // of this software and associated documentation files (the "Software"), to deal
  11 // in the Software without restriction, including without limitation the rights
  12 // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  13 // copies of the Software, and to permit persons to whom the Software is
  14 // furnished to do so, subject to the following conditions:
  15 //
  16 // The above copyright notice and this permission notice shall be included in
  17 // all copies or substantial portions of the Software.
  18 //
  19 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  20 // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  21 // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  22 // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  23 // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  24 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  25 // THE SOFTWARE.
  26
  27 #if NET_4_0
  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.Parallel.QueryNodes
  35 {
  36         internal class QueryJoinNode<TFirst, TSecond, TKey, TResult> : QueryMuxNode<TFirst, TSecond, TResult>
  37         {
  38                 struct VSlot<T>
  39                 {
  40                         public readonly bool HasValue;
  41                         public readonly T Value;
  42
  43                         public VSlot (T value)
  44                         {
  45                                 HasValue = true;
  46                                 Value = value;
  47                         }
  48                 }
  49
  50                 Func<TFirst, TKey> firstKeySelector;
  51                 Func<TSecond, TKey> secondKeySelector;
  52                 Func<TFirst, TSecond, TResult> resultSelector;
  53                 IEqualityComparer<TKey> comparer;
  54
  55                 internal QueryJoinNode (QueryBaseNode<TFirst> first,
  56                                         QueryBaseNode<TSecond> second,
  57                                         Func<TFirst, TKey> firstKeySelector,
  58                                         Func<TSecond, TKey> secondKeySelector,
  59                                         Func<TFirst, TSecond, TResult> resultSelector,
  60                                         IEqualityComparer<TKey> comparer) : base (first, second)
  61                 {
  62                         this.firstKeySelector = firstKeySelector;
  63                         this.secondKeySelector = secondKeySelector;
  64                         this.resultSelector = resultSelector;
  65                         this.comparer = comparer;
  66                 }
  67
  68                 internal override IEnumerable<TResult> GetSequential ()
  69                 {
  70                         return Parent.GetSequential ().Join (Second.GetSequential (),
  71                                                              firstKeySelector,
  72                                                              secondKeySelector,
  73                                                              resultSelector,
  74                                                              comparer);
  75                 }
  76
  77                 internal override IList<IEnumerable<TResult>> GetEnumerables (QueryOptions options)
  78                 {
  79                         var first = Parent.GetEnumerables (options);
  80                         var second = Second.GetEnumerables (options);
  81
  82                         if (first.Count != second.Count)
  83                                 throw new InvalidOperationException ("Internal size mismatch");
  84
  85                         var store = new ConcurrentDictionary<TKey, Tuple<VSlot<TFirst>, VSlot<TSecond>>> (comparer);
  86
  87                         return first
  88                                 .Select ((f, i) => GetEnumerable (f, second[i], store, firstKeySelector, secondKeySelector, resultSelector))
  89                                 .ToList ();
  90
  91                 }
  92
  93                 internal override IList<IEnumerable<KeyValuePair<long, TResult>>> GetOrderedEnumerables (QueryOptions options)
  94                 {
  95                         var first = Parent.GetOrderedEnumerables (options);
  96                         var second = Second.GetOrderedEnumerables (options);
  97
  98                         if (first.Count != second.Count)
  99                                 throw new InvalidOperationException ("Internal size mismatch");
 100
 101                         var store = new ConcurrentDictionary<TKey, Tuple<VSlot<KeyValuePair<long, TFirst>>, VSlot<KeyValuePair<long, TSecond>>>> (comparer);
 102
 103                         return first
 104                                 .Select ((f, i) => GetEnumerable<KeyValuePair<long, TFirst>, KeyValuePair<long, TSecond>, KeyValuePair<long, TResult>> (f,
 105                                                                   second[i],
 106                                                                   store,
 107                                                                   (e) => firstKeySelector (e.Value),
 108                                                                   (e) => secondKeySelector (e.Value),
 109                                                                   (e1, e2) => new KeyValuePair<long, TResult> (e1.Key, resultSelector (e1.Value, e2.Value))))
 110                                 .ToList ();
 111                 }
 112
 113                 IEnumerable<T> GetEnumerable<U, V, T> (IEnumerable<U> first,
 114                                                        IEnumerable<V> second,
 115                                                        ConcurrentDictionary<TKey, Tuple<VSlot<U>, VSlot<V>>> store,
 116                                                        Func<U, TKey> fKeySelect,
 117                                                        Func<V, TKey> sKeySelect,
 118                                                        Func<U, V, T> resultor)
 119                 {
 120                         IEnumerator<U> eFirst = first.GetEnumerator ();
 121                         IEnumerator<V> eSecond = second.GetEnumerator ();
 122
 123                         try {
 124                                 while (eFirst.MoveNext ()) {
 125                                         if (!eSecond.MoveNext ())
 126                                                 yield break;
 127
 128                                         U e1 = eFirst.Current;
 129                                         V e2 = eSecond.Current;
 130
 131                                         TKey key1 = fKeySelect (e1);
 132                                         TKey key2 = sKeySelect (e2);
 133
 134                                         if (comparer.Equals (key1, key2)) {
 135                                                 yield return resultor (e1, e2);
 136                                                 continue;
 137                                         }
 138
 139                                         Tuple<VSlot<U>, VSlot<V>> kvp;
 140
 141                                         do {
 142                                                 if (store.TryRemove (key1, out kvp) && kvp.Item2.HasValue) {
 143                                                         yield return resultor (e1, kvp.Item2.Value);
 144                                                         break;
 145                                                 }
 146                                         } while (!store.TryAdd (key1, Tuple.Create (new VSlot<U> (e1), new VSlot<V> ())));
 147
 148                                         do {
 149                                                 if (store.TryRemove (key2, out kvp) && kvp.Item1.HasValue) {
 150                                                         yield return resultor (kvp.Item1.Value, e2);
 151                                                         break;
 152                                                 }
 153                                         } while (!store.TryAdd (key2, Tuple.Create (new VSlot<U> (), new VSlot<V> (e2))));
 154                                 }
 155                         } finally {
 156                                 eFirst.Dispose ();
 157                                 eSecond.Dispose ();
 158                         }
 159                 }
 160         }
 161 }
 162
 163 #endif