class/Mono.Cecil/Mono.Cecil.Metadata/BlobHeap.cs

   1 //
   2 // BlobHeap.cs
   3 //
   4 // Author:
   5 //   Jb Evain (jbevain@gmail.com)
   6 //
   7 // (C) 2005 Jb Evain
   8 //
   9 // Permission is hereby granted, free of charge, to any person obtaining
  10 // a copy of this software and associated documentation files (the
  11 // "Software"), to deal in the Software without restriction, including
  12 // without limitation the rights to use, copy, modify, merge, publish,
  13 // distribute, sublicense, and/or sell copies of the Software, and to
  14 // permit persons to whom the Software is furnished to do so, subject to
  15 // the following conditions:
  16 //
  17 // The above copyright notice and this permission notice shall be
  18 // included in all copies or substantial portions of the Software.
  19 //
  20 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  21 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  22 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  23 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  24 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  25 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  26 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  27 //
  28
  29 namespace Mono.Cecil.Metadata {
  30
  31         using System;
  32         using System.Collections;
  33         using System.IO;
  34
  35         public class BlobHeap : MetadataHeap {
  36
  37                 internal BlobHeap (MetadataStream stream) : base (stream, MetadataStream.Blob)
  38                 {
  39                 }
  40
  41                 public byte [] Read (uint index)
  42                 {
  43                         return ReadBytesFromStream (index);
  44                 }
  45
  46                 public BinaryReader GetReader (uint index)
  47                 {
  48                         return new BinaryReader (new MemoryStream (Read (index)));
  49                 }
  50
  51                 public override void Accept (IMetadataVisitor visitor)
  52                 {
  53                         visitor.VisitBlobHeap (this);
  54                 }
  55         }
  56
  57         class ByteArrayEqualityComparer : IHashCodeProvider, IComparer {
  58
  59                 public static readonly ByteArrayEqualityComparer Instance = new ByteArrayEqualityComparer ();
  60
  61                 public int GetHashCode (object obj)
  62                 {
  63                         byte [] array = (byte []) obj;
  64
  65                         int hash = 0;
  66                         for (int i = 0; i < array.Length; i++)
  67                                 hash = (hash * 37) ^ array [i];
  68
  69                         return hash;
  70                 }
  71
  72                 public int Compare (object a, object b)
  73                 {
  74                         byte [] x = (byte []) a;
  75                         byte [] y = (byte []) b;
  76
  77                         if (x == null || y == null)
  78                                 return x == y ? 0 : 1;
  79
  80                         if (x.Length != y.Length)
  81                                 return 1;
  82
  83                         for (int i = 0; i < x.Length; i++)
  84                                 if (x [i] != y [i])
  85                                         return 1;
  86
  87                         return 0;
  88                 }
  89         }
  90 }