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

   1 //
   2 // QueryOrderByNode.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 QueryOrderByNode<T> : QueryOrderGuardNode<T>
  37         {
  38                 Comparison<T> comparison;
  39
  40                 public QueryOrderByNode (QueryBaseNode<T> parent, Comparison<T> comparison)
  41                         : base (parent, true)
  42                 {
  43                         this.comparison = comparison;
  44                 }
  45
  46
  47                 public QueryOrderByNode (QueryOrderByNode<T> parent, Comparison<T> comparison)
  48                         : base (parent.Parent, true)
  49                 {
  50                         this.comparison = MergeComparison (parent.ComparisonFunc, comparison);
  51                 }
  52
  53                 public Comparison<T> ComparisonFunc {
  54                         get {
  55                                 return comparison;
  56                         }
  57                 }
  58
  59                 internal override IEnumerable<T> GetSequential ()
  60                 {
  61                         return Parent.GetSequential ().OrderBy ((e) => e, new ComparisonComparer (comparison));
  62                 }
  63
  64                 private class ComparisonComparer : IComparer<T>
  65                 {
  66                         Comparison<T> comparison;
  67
  68                         internal ComparisonComparer (Comparison<T> comparison)
  69                         {
  70                                 this.comparison = comparison;
  71                         }
  72
  73                         int IComparer<T>.Compare (T x, T y)
  74                         {
  75                                 return comparison (x, y);
  76                         }
  77                 }
  78
  79                 internal override IList<IEnumerable<T>> GetEnumerables (QueryOptions options)
  80                 {
  81                         throw new InvalidOperationException ("Shouldn't be called");
  82                 }
  83
  84                 internal override IList<IEnumerable<KeyValuePair<long, T>>> GetOrderedEnumerables (QueryOptions options)
  85                 {
  86                         int partitionCount;
  87                         IList<T> aggregList = GetAggregatedList (out partitionCount);
  88                         IList<T> result = ParallelQuickSort<T>.Sort (aggregList, comparison);
  89
  90                         OrderablePartitioner<T> partitioner = ParallelPartitioner.CreateForStrips (result, 1);
  91
  92                         return WrapHelper.Wrap (partitioner.GetOrderablePartitions (options.PartitionCount));
  93                 }
  94
  95                 IList<T> GetAggregatedList (out int partitionCount)
  96                 {
  97                         AggregationList<T> result = null;
  98                         partitionCount = -1;
  99
 100                         ParallelExecuter.ProcessAndAggregate<T, IList<T>> (Parent, () => new List<T> (),
 101                                                                            LocalCall,
 102                                                                            (ls) => { result = new AggregationList<T> (ls); });
 103
 104                         return result;
 105                 }
 106
 107                 IList<T> LocalCall (IList<T> list, T element)
 108                 {
 109                         list.Add (element);
 110                         return list;
 111                 }
 112
 113                 static Comparison<T> MergeComparison (Comparison<T> source, Comparison<T> other)
 114                 {
 115                         return (e1, e2) => {
 116                                 int result = source (e1, e2);
 117                                 return result == 0 ? other (e1, e2) : result;
 118                         };
 119                 }
 120         }
 121 }
 122 #endif