source: branches/3044_variableScaling/HeuristicLab.ExtLibs/HeuristicLab.NRefactory/5.5.0/NRefactory-5.5.0/Utils/7BitEncodedInts.cs

// Copyright (c) 2011 Daniel Grunwald
// 
// 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.IO;

namespace ICSharpCode.NRefactory.Utils
{
  /// <summary>
  /// A binary reader that can read the output of BinaryWriterWith7BitEncodedInts.
  /// </summary>
  public sealed class BinaryReaderWith7BitEncodedInts : BinaryReader
  {
    public BinaryReaderWith7BitEncodedInts(Stream stream) : base(stream)
    {
    }
    
    public override short ReadInt16()
    {
      return unchecked((short)(ushort)base.Read7BitEncodedInt());
    }
    
    [CLSCompliant(false)]
    public override ushort ReadUInt16()
    {
      return unchecked((ushort)base.Read7BitEncodedInt());
    }
    
    public override int ReadInt32()
    {
      return base.Read7BitEncodedInt();
    }
    
    [CLSCompliant(false)]
    public override uint ReadUInt32()
    {
      return unchecked((uint)base.Read7BitEncodedInt());
    }
    
    public override long ReadInt64()
    {
      return unchecked((long)this.ReadUInt64());
    }
    
    [CLSCompliant(false)]
    public override ulong ReadUInt64()
    {
      ulong num = 0;
      int shift = 0;
      while (shift < 64) {
        byte b = this.ReadByte();
        num |= (ulong)(b & 127) << shift;
        shift += 7;
        if ((b & 128) == 0) {
          return num;
        }
      }
      throw new FormatException("Invalid 7-bit int64");
    }
  }

  /// <summary>
  /// A binary writer that encodes all integers as 7-bit-encoded-ints.
  /// </summary>
  public sealed class BinaryWriterWith7BitEncodedInts : BinaryWriter
  {
    public BinaryWriterWith7BitEncodedInts(Stream stream) : base(stream)
    {
    }
    
    public override void Write(short value)
    {
      base.Write7BitEncodedInt(unchecked((ushort)value));
    }
    
    [CLSCompliant(false)]
    public override void Write(ushort value)
    {
      base.Write7BitEncodedInt(value);
    }
    
    public override void Write(int value)
    {
      base.Write7BitEncodedInt(value);
    }
    
    [CLSCompliant(false)]
    public override void Write(uint value)
    {
      base.Write7BitEncodedInt(unchecked((int)value));
    }
    
    public override void Write(long value)
    {
      this.Write(unchecked((ulong)value));
    }
    
    [CLSCompliant(false)]
    public override void Write(ulong value)
    {
      while (value >= 128) {
        this.Write(unchecked((byte)(value | 128u)));
        value >>= 7;
      }
      this.Write(unchecked((byte)value));
    }
  }
}