性能:BinaryFormatter与XmlSerializer

Question

我经常读到BinaryFormatter比XmlSerializer具有更好的性能.出于好奇,我写了一个测试应用程序.

一个wtf时刻......为什么Xml比Bin快得多(特别是反序列化)？

using System;
using System.Collections.Generic;
using System.Runtime.Serialization;
using System.Xml.Serialization;
using System.Runtime.Serialization.Formatters.Binary;
using System.IO;

namespace SerPlayground
{
    class Program
    {
        static void Main(string[] args)
        {
            var items = new List<TestClass>();
            for (int i = 0; i < 1E6; i++)
            {
                items.Add(new TestClass() { Name = i.ToString(), Id = i });
            }

            File.Delete("test.bin");
            using (var target = new FileStream("test.bin", FileMode.OpenOrCreate))
            {
                System.Threading.Thread.Sleep(1000);
                var bin = new BinaryFormatter();
                var start = DateTime.Now;
                bin.Serialize(target, items);
                Console.WriteLine("Bin: {0}", (DateTime.Now - start).TotalMilliseconds);

                target.Position = 0;
                System.Threading.Thread.Sleep(1000);
                start = DateTime.Now;
                bin.Deserialize(target);
                Console.WriteLine("Bin-D: {0}", (DateTime.Now - start).TotalMilliseconds);
            }

            File.Delete("test.xml");
            using (var target = new FileStream("test.xml", FileMode.OpenOrCreate))
            {
                System.Threading.Thread.Sleep(1000);
                var xml = new XmlSerializer(typeof(List<TestClass>));
                var start = DateTime.Now;
                xml.Serialize(target, items);
                Console.WriteLine("Xml: {0}", (DateTime.Now - start).TotalMilliseconds);

                target.Position = 0;
                System.Threading.Thread.Sleep(1000);
                start = DateTime.Now;
                xml.Deserialize(target);
                Console.WriteLine("Xml-D: {0}", (DateTime.Now - start).TotalMilliseconds);
           }

            Console.ReadKey();
        }
    }

    [Serializable]
    public class TestClass
    {
        public string Name { get; set; }
        public int Id { get; set; }
    }
}

我的结果:

Bin: 13472.7706
Bin-D: 121131.9284
Xml: 8917.51
Xml-D: 12841.7345

Answer 1

因为您正在序列化没有任何属性的对象.

如果序列化实际包含某些数据的不同内容(例如字符串),则二进制序列化器比XML序列化器快得多.

我对您的代码进行了此更改:

items.Add("asfd");

我得到这个结果:

Xml: 1219.0541
Bin: 165.0002

差异的一部分当然是XML文件大约是二进制文件的十倍.