mcs/class/corlib/System/ArraySegment.cs

   1 //
   2 // ArraySegment.cs
   3 //
   4 // Authors:
   5 //  Ben Maurer (bmaurer@ximian.com)
   6 //  Jensen Somers <jensen.somers@gmail.com>
   7 //
   8 // Copyright (C) 2004 Novell
   9 //
  10 // Permission is hereby granted, free of charge, to any person obtaining
  11 // a copy of this software and associated documentation files (the
  12 // "Software"), to deal in the Software without restriction, including
  13 // without limitation the rights to use, copy, modify, merge, publish,
  14 // distribute, sublicense, and/or sell copies of the Software, and to
  15 // permit persons to whom the Software is furnished to do so, subject to
  16 // the following conditions:
  17 //
  18 // The above copyright notice and this permission notice shall be
  19 // included in all copies or substantial portions of the Software.
  20 //
  21 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  22 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  23 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  24 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  25 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  26 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  27 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  28 //
  29 #if NET_2_0
  30 namespace System {
  31         [Serializable]
  32         public struct ArraySegment <T> {
  33                 T [] array;
  34                 int offset, count;
  35
  36                 public ArraySegment (T [] array, int offset, int count)
  37                 {
  38                         if (array == null)
  39                                 throw new ArgumentNullException ("array");
  40
  41                         if (offset < 0)
  42                                 throw new ArgumentOutOfRangeException ("offset", "Non-negative number required.");
  43
  44                         if (count < 0)
  45                                 throw new ArgumentOutOfRangeException ("count", "Non-negative number required.");
  46
  47                         if (offset > array.Length)
  48                                 throw new ArgumentException ("out of bounds");
  49
  50                         // now offset is valid, or just beyond the end.
  51                         // Check count -- do it this way to avoid overflow on 'offset + count'
  52                         if (array.Length - offset < count)
  53                                 throw new ArgumentException ("out of bounds", "offset");
  54
  55                         this.array = array;
  56                         this.offset = offset;
  57                         this.count = count;
  58                 }
  59
  60                 public ArraySegment (T [] array)
  61                 {
  62                         if (array == null)
  63                                 throw new ArgumentNullException ("array");
  64
  65                         this.array = array;
  66                         this.offset = 0;
  67                         this.count = array.Length;
  68                 }
  69
  70                 public T [] Array {
  71                         get { return array; }
  72                 }
  73
  74                 public int Offset {
  75                         get { return offset; }
  76                 }
  77
  78                 public int Count {
  79                         get { return count; }
  80                 }
  81
  82                 public override bool Equals (Object obj)
  83                 {
  84                         if (obj is ArraySegment<T>) {
  85                                 return this.Equals((ArraySegment<T>) obj);
  86                         }
  87                         return false;
  88                 }
  89
  90                 public bool Equals (ArraySegment<T> obj)
  91                 {
  92                         if ((this.array == obj.Array) && (this.offset == obj.Offset) && (this.count == obj.Count))
  93                                 return true;
  94                         return false;
  95                 }
  96
  97                 public override int GetHashCode ()
  98                 {
  99                         return ((this.array.GetHashCode() ^ this.offset) ^ this.count);
 100                 }
 101
 102                 public static bool operator ==(ArraySegment<T> a, ArraySegment<T> b)
 103                 {
 104                         return a.Equals(b);
 105                 }
 106
 107                 public static bool operator !=(ArraySegment<T> a, ArraySegment<T> b)
 108                 {
 109                         return !(a.Equals(b));
 110                 }
 111         }
 112 }
 113 #endif