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 namespace System {
  30         [Serializable]
  31         public struct ArraySegment <T> {
  32                 T [] array;
  33                 int offset, count;
  34
  35                 public ArraySegment (T [] array, int offset, int count)
  36                 {
  37                         if (array == null)
  38                                 throw new ArgumentNullException ("array");
  39
  40                         if (offset < 0)
  41                                 throw new ArgumentOutOfRangeException ("offset", "Non-negative number required.");
  42
  43                         if (count < 0)
  44                                 throw new ArgumentOutOfRangeException ("count", "Non-negative number required.");
  45
  46                         if (offset > array.Length)
  47                                 throw new ArgumentException ("out of bounds");
  48
  49                         // now offset is valid, or just beyond the end.
  50                         // Check count -- do it this way to avoid overflow on 'offset + count'
  51                         if (array.Length - offset < count)
  52                                 throw new ArgumentException ("out of bounds", "offset");
  53
  54                         this.array = array;
  55                         this.offset = offset;
  56                         this.count = count;
  57                 }
  58
  59                 public ArraySegment (T [] array)
  60                 {
  61                         if (array == null)
  62                                 throw new ArgumentNullException ("array");
  63
  64                         this.array = array;
  65                         this.offset = 0;
  66                         this.count = array.Length;
  67                 }
  68
  69                 public T [] Array {
  70                         get { return array; }
  71                 }
  72
  73                 public int Offset {
  74                         get { return offset; }
  75                 }
  76
  77                 public int Count {
  78                         get { return count; }
  79                 }
  80
  81                 public override bool Equals (Object obj)
  82                 {
  83                         if (obj is ArraySegment<T>) {
  84                                 return this.Equals((ArraySegment<T>) obj);
  85                         }
  86                         return false;
  87                 }
  88
  89                 public bool Equals (ArraySegment<T> obj)
  90                 {
  91                         if ((this.array == obj.Array) && (this.offset == obj.Offset) && (this.count == obj.Count))
  92                                 return true;
  93                         return false;
  94                 }
  95
  96                 public override int GetHashCode ()
  97                 {
  98                         return ((this.array.GetHashCode() ^ this.offset) ^ this.count);
  99                 }
 100
 101                 public static bool operator ==(ArraySegment<T> a, ArraySegment<T> b)
 102                 {
 103                         return a.Equals(b);
 104                 }
 105
 106                 public static bool operator !=(ArraySegment<T> a, ArraySegment<T> b)
 107                 {
 108                         return !(a.Equals(b));
 109                 }
 110         }
 111 }