mcs/class/corlib/System.Collections.Concurrent/Partitioner.cs

   1 //
   2 // Partitioner.cs
   3 //
   4 // Author:
   5 //       Jérémie "Garuma" Laval <jeremie.laval@gmail.com>
   6 //
   7 // Copyright (c) 2009 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 using System;
  28 using System.Collections.Generic;
  29
  30 #if NET_4_0 || BOOTSTRAP_NET_4_0
  31
  32 namespace System.Collections.Concurrent
  33 {
  34         using Partitioners;
  35
  36         public static class Partitioner
  37         {
  38                 public static OrderablePartitioner<TSource> Create<TSource> (IEnumerable<TSource> source)
  39                 {
  40                         IList<TSource> tempIList = source as IList<TSource>;
  41                         if (tempIList != null)
  42                                 return Create (tempIList, true);
  43
  44                         return new EnumerablePartitioner<TSource> (source);
  45                 }
  46
  47                 public static OrderablePartitioner<TSource> Create<TSource> (TSource[] array, bool loadBalance)
  48                 {
  49                         return Create ((IList<TSource>)array, loadBalance);
  50                 }
  51
  52                 public static OrderablePartitioner<TSource> Create<TSource> (IList<TSource> list, bool loadBalance)
  53                 {
  54                         return new ListPartitioner<TSource> (list);
  55                 }
  56
  57                 public static OrderablePartitioner<Tuple<int, int>> Create (int fromInclusive,
  58                                                                             int toExclusive)
  59                 {
  60                         // This formula that is somewhat non-straighforward was guessed based on MS output
  61                         int rangeSize = (toExclusive - fromInclusive) / (Environment.ProcessorCount * 3);
  62                         if (rangeSize < 1)
  63                                 rangeSize = 1;
  64
  65                         return Create (fromInclusive, toExclusive, rangeSize);
  66                 }
  67
  68                 public static OrderablePartitioner<Tuple<int, int>> Create (int fromInclusive,
  69                                                                             int toExclusive,
  70                                                                             int rangeSize)
  71                 {
  72                         if (fromInclusive >= toExclusive)
  73                                 throw new ArgumentOutOfRangeException ("toExclusive");
  74                         if (rangeSize <= 0)
  75                                 throw new ArgumentOutOfRangeException ("rangeSize");
  76
  77                         return new UserRangePartitioner (fromInclusive, toExclusive, rangeSize);
  78                 }
  79
  80                 public static OrderablePartitioner<Tuple<long, long>> Create (long fromInclusive,
  81                                                                               long toExclusive)
  82                 {
  83                         long rangeSize = (toExclusive - fromInclusive) / (Environment.ProcessorCount * 3);
  84                         if (rangeSize < 1)
  85                                 rangeSize = 1;
  86
  87                         return Create (fromInclusive, toExclusive, rangeSize);
  88                 }
  89
  90                 public static OrderablePartitioner<Tuple<long, long>> Create (long fromInclusive,
  91                                                                               long toExclusive,
  92                                                                               long rangeSize)
  93                 {
  94                         if (rangeSize <= 0)
  95                                 throw new ArgumentOutOfRangeException ("rangeSize");
  96                         if (fromInclusive >= toExclusive)
  97                                 throw new ArgumentOutOfRangeException ("toExclusive");
  98
  99                         return new UserLongRangePartitioner (fromInclusive, toExclusive, rangeSize);
 100                 }
 101         }
 102
 103         public abstract class Partitioner<TSource>
 104         {
 105                 protected Partitioner ()
 106                 {
 107
 108                 }
 109
 110                 public virtual IEnumerable<TSource> GetDynamicPartitions ()
 111                 {
 112                         if (!SupportsDynamicPartitions)
 113                                 throw new NotSupportedException ();
 114
 115                         return null;
 116                 }
 117
 118                 public abstract IList<IEnumerator<TSource>> GetPartitions (int partitionCount);
 119
 120                 public virtual bool SupportsDynamicPartitions {
 121                         get {
 122                                 return false;
 123                         }
 124                 }
 125         }
 126 }
 127 #endif