mcs/class/System.Core/System.Linq/Internal/QueryNodes/QuerySelectManyNode.cs

   1 #if NET_4_0
   2 //
   3 // QueryConcatNode.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
  33 namespace System.Linq
  34 {
  35         internal class QuerySelectManyNode<TSource, TCollection, TResult> : QueryStreamNode<TResult, TSource>
  36         {
  37                 Func<TSource, IEnumerable<TCollection>> collectionSelector;
  38                 Func<TSource, int, IEnumerable<TCollection>> collectionSelectorIndexed;
  39                 Func<TSource, TCollection, TResult> resultSelector;
  40
  41                 internal QuerySelectManyNode (QueryBaseNode<TSource> parent,
  42                                               Func<TSource, int, IEnumerable<TCollection>> collectionSelectorIndexed,
  43                                               Func<TSource, TCollection, TResult> resultSelector)
  44                         : base (parent, true)
  45                 {
  46                         this.collectionSelectorIndexed = collectionSelectorIndexed;
  47                         this.resultSelector = resultSelector;
  48                 }
  49
  50                 internal QuerySelectManyNode (QueryBaseNode<TSource> parent,
  51                                               Func<TSource, IEnumerable<TCollection>> collectionSelector,
  52                                               Func<TSource, TCollection, TResult> resultSelector)
  53                         : base (parent, false)
  54                 {
  55                         this.collectionSelector = collectionSelector;
  56                         this.resultSelector = resultSelector;
  57                 }
  58
  59                 internal override IEnumerable<TResult> GetSequential ()
  60                 {
  61                         IEnumerable<TSource> source = Parent.GetSequential ();
  62
  63                         if (IsIndexed)
  64                                 return source.SelectMany (collectionSelectorIndexed, resultSelector);
  65                         else
  66                                 return source.SelectMany (collectionSelector, resultSelector);
  67                 }
  68
  69                 internal override IList<IEnumerable<TResult>> GetEnumerables (QueryOptions options)
  70                 {
  71                         IEnumerable<TResult>[] result = null;
  72
  73                         if (IsIndexed) {
  74                                 IList<IEnumerable<KeyValuePair<long, TSource>>> enumerables = Parent.GetOrderedEnumerables (options);
  75                                 result = new IEnumerable<TResult>[enumerables.Count];
  76
  77                                 for (int i = 0; i < enumerables.Count; i++)
  78                                         result[i] = GetEnumerableInternal<KeyValuePair<long, TSource>> (enumerables[i],
  79                                                                                                         (kv) => collectionSelectorIndexed (kv.Value, (int)kv.Key),
  80                                                                                                         (e, c) => resultSelector (e.Value, c));
  81                         } else {
  82                                 IList<IEnumerable<TSource>> enumerables = Parent.GetEnumerables (options);
  83                                 result = new IEnumerable<TResult>[enumerables.Count];
  84
  85                                 for (int i = 0; i < enumerables.Count; i++)
  86                                         result[i] = GetEnumerableInternal<TSource> (enumerables[i],
  87                                                                                     collectionSelector,
  88                                                                                     (e, c) => resultSelector (e, c));
  89                         }
  90
  91                         return result;
  92                 }
  93
  94                 // This one is gonna be tricky
  95                 internal override IList<IEnumerable<KeyValuePair<long, TResult>>> GetOrderedEnumerables (QueryOptions options)
  96                 {
  97                         throw new NotImplementedException ();
  98                 }
  99
 100                 IEnumerable<TResult> GetEnumerableInternal<T> (IEnumerable<T> source,
 101                                                                Func<T, IEnumerable<TCollection>> collectionner,
 102                                                                Func<T, TCollection, TResult> packer)
 103                 {
 104                         foreach (T element in source)
 105                                 foreach (TCollection item in collectionner (element))
 106                                         yield return packer (element, item);
 107                 }
 108
 109                 IEnumerable<KeyValuePair<long, TResult>> GetOrderedEnumerableInternal (IEnumerable<KeyValuePair<long, TSource>> source,
 110                                                                                        Barrier barrier)
 111                 {
 112                         foreach (KeyValuePair<long, TSource> element in source) {
 113                                 IEnumerable<TCollection> collection = collectionSelectorIndexed (element.Value, (int)element.Key);
 114
 115                                 foreach (TCollection item in collection)
 116                                         yield return new KeyValuePair<long, TResult> (-1, resultSelector (element.Value, item));
 117                         }
 118                 }
 119         }
 120 }
 121
 122 #endif