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

   1 //
   2 // QueryZipNode.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 || MOBILE
  28 using System;
  29 using System.Threading;
  30 using System.Linq;
  31 using System.Collections.Generic;
  32 using System.Collections.Concurrent;
  33
  34 namespace System.Linq.Parallel.QueryNodes
  35 {
  36         internal class QueryZipNode<TFirst, TSecond, TResult> : QueryMuxNode<TFirst, TSecond, TResult>
  37         {
  38                 Func<TFirst, TSecond, TResult> resultSelector;
  39
  40                 public QueryZipNode (Func<TFirst, TSecond, TResult> resultSelector, QueryBaseNode<TFirst> first, QueryBaseNode<TSecond> second)
  41                         : base (first, second)
  42                 {
  43                         this.resultSelector = resultSelector;
  44                 }
  45
  46                 // If strict is set to `true', the zip'ing process will throw if sequences length mistmatches
  47                 public bool Strict {
  48                         get;
  49                         set;
  50                 }
  51
  52                 internal override IEnumerable<TResult> GetSequential ()
  53                 {
  54                         IEnumerable<TFirst> first = Parent.GetSequential ();
  55                         IEnumerable<TSecond> second = Second.GetSequential ();
  56
  57                         return first.Zip (second, resultSelector);
  58                 }
  59
  60                 internal override IList<IEnumerable<TResult>> GetEnumerables (QueryOptions options)
  61                 {
  62                         var first = Parent.GetEnumerables (options);
  63                         var second = Second.GetEnumerables (options);
  64
  65                         if (first.Count != second.Count)
  66                                 throw new InvalidOperationException ("Internal size mismatch");
  67
  68                         return first
  69                                 .Select ((f, i) => GetEnumerable (f, second[i]))
  70                                 .ToList ();
  71                 }
  72
  73                 IEnumerable<TResult> GetEnumerable (IEnumerable<TFirst> first, IEnumerable<TSecond> second)
  74                 {
  75                         IEnumerator<TFirst> eFirst = first.GetEnumerator ();
  76                         IEnumerator<TSecond> eSecond = second.GetEnumerator ();
  77
  78                         try {
  79                                 while (eFirst.MoveNext ()) {
  80                                         if (!eSecond.MoveNext ()) {
  81                                                 if (Strict)
  82                                                         throw new QueryZipException ();
  83                                                 else
  84                                                         yield break;
  85                                         }
  86
  87                                         yield return resultSelector (eFirst.Current, eSecond.Current);
  88                                 }
  89                                 if (Strict && eSecond.MoveNext ())
  90                                         throw new QueryZipException ();
  91                         } finally {
  92                                 eFirst.Dispose ();
  93                                 eSecond.Dispose ();
  94                         }
  95                 }
  96
  97                 internal override IList<IEnumerable<KeyValuePair<long, TResult>>> GetOrderedEnumerables (QueryOptions options)
  98                 {
  99                         var first = Parent.GetOrderedEnumerables (options);
 100                         var second = Second.GetOrderedEnumerables (options);
 101
 102                         if (first.Count != second.Count)
 103                                 throw new InvalidOperationException ("Internal size mismatch");
 104
 105                         var store1 = new KeyValuePair<long, TFirst>[first.Count];
 106                         var store2 = new KeyValuePair<long, TSecond>[second.Count];
 107
 108                         var barrier = new Barrier (first.Count, delegate {
 109                                 Array.Sort (store1, (e1, e2) => e1.Key.CompareTo (e2.Key));
 110                                 Array.Sort (store2, (e1, e2) => e1.Key.CompareTo (e2.Key));
 111                         });
 112
 113                         return first
 114                                 .Select ((f, i) => GetEnumerable (f, second[i], i , store1, store2, barrier))
 115                                 .ToList ();
 116                 }
 117
 118                 IEnumerable<KeyValuePair<long, TResult>> GetEnumerable (IEnumerable<KeyValuePair<long, TFirst>> first,
 119                                                                         IEnumerable<KeyValuePair<long, TSecond>> second,
 120                                                                         int index,
 121                                                                         KeyValuePair<long, TFirst>[] store1,
 122                                                                         KeyValuePair<long, TSecond>[] store2,
 123                                                                         Barrier barrier)
 124                 {
 125                         var eFirst = first.GetEnumerator ();
 126                         var eSecond = second.GetEnumerator ();
 127
 128                         try {
 129                                 while (eFirst.MoveNext ()) {
 130                                         if (!eSecond.MoveNext ()) {
 131                                                 if (Strict)
 132                                                         throw new QueryZipException ();
 133                                                 else
 134                                                         break;
 135                                         }
 136
 137                                         store1[index] = eFirst.Current;
 138                                         store2[index] = eSecond.Current;
 139
 140                                         barrier.SignalAndWait ();
 141
 142                                         yield return new KeyValuePair<long, TResult> (store1[index].Key,
 143                                                                                       resultSelector (store1[index].Value, store2[index].Value));
 144                                 }
 145                                 if (Strict && eSecond.MoveNext ())
 146                                         throw new QueryZipException ();
 147                         } finally {
 148                                 barrier.RemoveParticipant ();
 149                                 eFirst.Dispose ();
 150                                 eSecond.Dispose ();
 151                         }
 152                 }
 153         }
 154
 155         internal class QueryZipException : Exception
 156         {
 157         }
 158 }
 159
 160 #endif