I read very often that the BinaryFormatter has better performance then XmlSerializer. Out of curiosity, I wrote a test-app.
a wtf moment... why is Xml so much faster than Bin (especially the deserialization)?
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; }
}
}
my results:
Bin: 13472.7706
Bin-D: 121131.9284
Xml: 8917.51
Xml-D: 12841.7345
Because you are serialising an object that doesn't have any properties.
If you serialise something different that actually contains some data, like for example a string, the binary serialiser is a lot faster than the XML serialiser.
I did this change to your code:
items.Add("asfd");
and I get this result:
Xml: 1219.0541
Bin: 165.0002
A part of the difference is of course that the XML file is about ten times larger than the binary file.