source: branches/2870_AutoDiff-nuget/HeuristicLab.ExtLibs/HeuristicLab.Cecil/0.9.5/Mono.Cecil-0.9.5/Mono.Cecil/Mono.Cecil.Metadata/StringHeap.cs

//
// StringHeap.cs
//
// Author:
//   Jb Evain (jbevain@gmail.com)
//
// Copyright (c) 2008 - 2011 Jb Evain
//
// Permission is hereby granted, free of charge, to any person obtaining
// a copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to
// permit persons to whom the Software is furnished to do so, subject to
// the following conditions:
//
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
//

using System;
using System.Collections.Generic;
using System.Text;

using Mono.Cecil.PE;

namespace Mono.Cecil.Metadata {

  class StringHeap : Heap {

    readonly Dictionary<uint, string> strings = new Dictionary<uint, string> ();

    public StringHeap (Section section, uint start, uint size)
      : base (section, start, size)
    {
    }

    public string Read (uint index)
    {
      if (index == 0)
        return string.Empty;

      string @string;
      if (strings.TryGetValue (index, out @string))
        return @string;

      if (index > Size - 1)
        return string.Empty;

      @string = ReadStringAt (index);
      if (@string.Length != 0)
        strings.Add (index, @string);

      return @string;
    }

    protected virtual string ReadStringAt (uint index)
    {
      int length = 0;
      byte [] data = Section.Data;
      int start = (int) (index + Offset);

      for (int i = start; ; i++) {
        if (data [i] == 0)
          break;

        length++;
      }

      return Encoding.UTF8.GetString (data, start, length);
    }
  }
}