Object Mapper Benchmark

ConversionTest.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Linq.Expressions;
using System.Reflection.Emit;
using AutoMapper;
using BenchmarkDotNet.Attributes;
using ExpressMapper.Extensions;

namespace AutoMapperBenchMark
{
    public class ConversionTest
    {
        private readonly List<Pessoa> _pessoas;
        private readonly Func<Pessoa, PessoaViewModel> _pessoaMapper;
        private readonly Func<Pessoa, PessoaViewModel> _pessoaMapperWithIl;
        private readonly Func<Pessoa, PessoaViewModel> _pessoaDoMap;

        public ConversionTest()
        {
            Mapper.Initialize(c => c.AddProfiles(typeof(Program).Assembly));

            ExpressMapper.Mapper.Register<Pessoa, PessoaViewModel>();
            ExpressMapper.Mapper.Compile();

            _pessoaMapper = CreateMap<Pessoa, PessoaViewModel>();

            _pessoaMapperWithIl = CreateMapWithIL<Pessoa, PessoaViewModel>();

            _pessoaDoMap = pessoa =>
            {
                var map = new PessoaViewModel();
                map.Casado = pessoa.Casado;
                map.DataNascimento = pessoa.DataNascimento;
                map.Id = pessoa.Id;
                map.Idade = pessoa.Idade;
                map.Nome = pessoa.Nome;
                return map;
            };

            _pessoas = Enumerable.Range(1, 100)
                .Select(x => new Pessoa(x, $"Pessoa {x}", x + 10, DateTime.Today.AddYears(x), x % 2 == 0))
                .ToList();
        }

        [Benchmark]
        public void SelfCoding()
        {
            var pessoasVM = new List<PessoaViewModel>();
            foreach (var pessoa in _pessoas)
                pessoasVM.Add(new PessoaViewModel
                {
                    Casado = pessoa.Casado,
                    DataNascimento = pessoa.DataNascimento,
                    Id = pessoa.Id,
                    Idade = pessoa.Idade,
                    Nome = pessoa.Nome
                });
        }

        [Benchmark]
        public void WithCustomExpressionEmitMapper()
        {
            var pessoasVM = new List<PessoaViewModel>();
            foreach (var pessoa in _pessoas)
                pessoasVM.Add(_pessoaMapper(pessoa));
        }

        [Benchmark]
        public void WithAutoMapper()
        {
            var pessoasVM = new List<PessoaViewModel>();
            foreach (var pessoa in _pessoas)
                pessoasVM.Add(Mapper.Instance.Map<PessoaViewModel>(pessoa));
        }

        [Benchmark]
        public void WithExpressMapper()
        {
            var pessoasVM = new List<PessoaViewModel>();
            foreach (var pessoa in _pessoas)
                pessoasVM.Add(pessoa.Map<Pessoa, PessoaViewModel>());
        }

        [Benchmark]
        public void WithoutUsingMethod()
        {
            var pessoasVM = new List<PessoaViewModel>();
            foreach (var pessoa in _pessoas)
            {
                var map = new PessoaViewModel();
                map.Casado = pessoa.Casado;
                map.DataNascimento = pessoa.DataNascimento;
                map.Id = pessoa.Id;
                map.Idade = pessoa.Idade;
                map.Nome = pessoa.Nome;
                pessoasVM.Add(map);
            }
        }

        [Benchmark]
        public void WithCustomILEmitMapper()
        {
            var pessoasVM = new List<PessoaViewModel>();
            foreach (var pessoa in _pessoas)
                pessoasVM.Add(_pessoaMapperWithIl.Invoke(pessoa));
        }

        public static Func<TSource, TDestination> CreateMapWithIL<TSource, TDestination>()
        {
            var sourceType = typeof(TSource);
            var destinationType = typeof(TDestination);
            var dynamicMethod = new DynamicMethod("Converter", destinationType, new[] { sourceType });

            var ilGenerator = dynamicMethod.GetILGenerator();

            var constructorInfo = destinationType.GetConstructor(new Type[0]);
            ilGenerator.Emit(OpCodes.Newobj, constructorInfo);

            var propertiesToMap = sourceType.GetProperties()
                .Concat(destinationType.GetProperties())
                .GroupBy(p => p.Name)
                .Where(g => g.Count() == 2)
                .Select(g => g.Key)
                .ToList();

            foreach (var propName in propertiesToMap)
            {
                ilGenerator.Emit(OpCodes.Dup);
                ilGenerator.Emit(OpCodes.Ldarg_0);
                ilGenerator.Emit(OpCodes.Call, sourceType.GetMethod($"get_{propName}"));
                ilGenerator.Emit(OpCodes.Call, destinationType.GetMethod($"set_{propName}"));
            }

            ilGenerator.Emit(OpCodes.Ret);

            return (Func<TSource, TDestination>)dynamicMethod.CreateDelegate(typeof(Func<TSource, TDestination>));
        }

        public static Func<TSource, TDestination> CreateMap<TSource, TDestination>()
        {
            var sourceType = typeof(TSource);
            var destinationType = typeof(TDestination);
            var constructorInfo = destinationType.GetConstructor(new Type[0]);

            var labelTarget = Expression.Label(destinationType);

            var destinationVariable = Expression.Variable(destinationType, "destination");
            var sourceExpression = Expression.Parameter(sourceType, "source");


            var propertiesToMap = sourceType.GetProperties()
                .Concat(destinationType.GetProperties())
                .GroupBy(p => p.Name)
                .Where(g => g.Count() == 2)
                .Select(g => g.Key)
                .ToList();

            var expressions = propertiesToMap
                .Select(pn => Expression.Assign(Expression.Property(destinationVariable, pn), Expression.Property(sourceExpression, pn)))
                .Cast<Expression>()
                .ToList();

            expressions.Insert(0, Expression.Assign(destinationVariable, Expression.New(constructorInfo)));
            expressions.Add(Expression.Return(labelTarget, destinationVariable));
            expressions.Add(Expression.Label(labelTarget, Expression.Convert(Expression.Constant(default(TDestination)), typeof(TDestination))));
            var blockExpression = Expression.Block(new[] { destinationVariable }, expressions);
            var expression = Expression.Lambda<Func<TSource, TDestination>>(blockExpression, sourceExpression);
            return expression.Compile();
        }
    }
}

packages.config

<?xml version="1.0" encoding="utf-8"?>
<packages>
  <package id="AutoMapper" version="5.1.1" targetFramework="net461" />
  <package id="BenchmarkDotNet" version="0.9.9" targetFramework="net461" />
  <package id="BenchmarkDotNet.Core" version="0.9.9" targetFramework="net461" />
  <package id="BenchmarkDotNet.Toolchains.Roslyn" version="0.9.9" targetFramework="net461" />
  <package id="Expressmapper" version="1.8.3" targetFramework="net461" />
  <package id="Microsoft.CodeAnalysis.Analyzers" version="1.1.0" targetFramework="net461" />
  <package id="Microsoft.CodeAnalysis.Common" version="1.3.2" targetFramework="net461" />
  <package id="Microsoft.CodeAnalysis.CSharp" version="1.3.2" targetFramework="net461" />
  <package id="System.AppContext" version="4.1.0" targetFramework="net461" />
  <package id="System.Collections" version="4.0.11" targetFramework="net461" />
  <package id="System.Collections.Concurrent" version="4.0.12" targetFramework="net461" />
  <package id="System.Collections.Immutable" version="1.2.0" targetFramework="net461" />
  <package id="System.Console" version="4.0.0" targetFramework="net461" />
  <package id="System.Diagnostics.Debug" version="4.0.11" targetFramework="net461" />
  <package id="System.Diagnostics.FileVersionInfo" version="4.0.0" targetFramework="net461" />
  <package id="System.Diagnostics.StackTrace" version="4.0.1" targetFramework="net461" />
  <package id="System.Diagnostics.Tools" version="4.0.1" targetFramework="net461" />
  <package id="System.Dynamic.Runtime" version="4.0.11" targetFramework="net461" />
  <package id="System.Globalization" version="4.0.11" targetFramework="net461" />
  <package id="System.IO.FileSystem" version="4.0.1" targetFramework="net461" />
  <package id="System.IO.FileSystem.Primitives" version="4.0.1" targetFramework="net461" />
  <package id="System.Linq" version="4.1.0" targetFramework="net461" />
  <package id="System.Linq.Expressions" version="4.1.0" targetFramework="net461" />
  <package id="System.Reflection" version="4.1.0" targetFramework="net461" />
  <package id="System.Reflection.Metadata" version="1.3.0" targetFramework="net461" />
  <package id="System.Reflection.Primitives" version="4.0.1" targetFramework="net461" />
  <package id="System.Resources.ResourceManager" version="4.0.1" targetFramework="net461" />
  <package id="System.Runtime" version="4.1.0" targetFramework="net461" />
  <package id="System.Runtime.Extensions" version="4.1.0" targetFramework="net461" />
  <package id="System.Runtime.Handles" version="4.0.1" targetFramework="net461" />
  <package id="System.Runtime.InteropServices" version="4.1.0" targetFramework="net461" />
  <package id="System.Runtime.Numerics" version="4.0.1" targetFramework="net461" />
  <package id="System.Security.Cryptography.Algorithms" version="4.2.0" targetFramework="net461" />
  <package id="System.Security.Cryptography.Encoding" version="4.0.0" targetFramework="net461" />
  <package id="System.Security.Cryptography.Primitives" version="4.0.0" targetFramework="net461" />
  <package id="System.Security.Cryptography.X509Certificates" version="4.1.0" targetFramework="net461" />
  <package id="System.Text.Encoding" version="4.0.11" targetFramework="net461" />
  <package id="System.Text.Encoding.CodePages" version="4.0.1" targetFramework="net461" />
  <package id="System.Text.Encoding.Extensions" version="4.0.11" targetFramework="net461" />
  <package id="System.Threading" version="4.0.11" targetFramework="net461" />
  <package id="System.Threading.Tasks" version="4.0.11" targetFramework="net461" />
  <package id="System.Threading.Tasks.Extensions" version="4.0.0" targetFramework="net461" />
  <package id="System.Threading.Tasks.Parallel" version="4.0.1" targetFramework="net461" />
  <package id="System.Threading.Thread" version="4.0.0" targetFramework="net461" />
  <package id="System.Xml.ReaderWriter" version="4.0.11" targetFramework="net461" />
  <package id="System.Xml.XDocument" version="4.0.11" targetFramework="net461" />
  <package id="System.Xml.XmlDocument" version="4.0.1" targetFramework="net461" />
  <package id="System.Xml.XPath" version="4.0.1" targetFramework="net461" />
  <package id="System.Xml.XPath.XDocument" version="4.0.1" targetFramework="net461" />
</packages>

Pessoa.cs

using System;

namespace AutoMapperBenchMark
{
    public class Pessoa
    {
        public Pessoa(long id, string nome, int idade, DateTime dataNascimento, bool casado)
        {
            Id = id;
            Nome = nome;
            Idade = idade;
            DataNascimento = dataNascimento;
            Casado = casado;
        }

        public long Id { get; }
        public string Nome { get; }
        public int Idade { get; }
        public DateTime DataNascimento { get; }
        public bool Casado { get; }
    }
}

PessoaProfile.cs

using AutoMapper;

namespace AutoMapperBenchMark
{
    public sealed class PessoaProfile : Profile
    {
        public PessoaProfile()
        {
            CreateMap<Pessoa, PessoaViewModel>();
        }
    }
}

PessoaViewModel.cs

using System;

namespace AutoMapperBenchMark
{
    public class PessoaViewModel
    {
        public long Id { get; set; }
        public string Nome { get; set; }
        public int Idade { get; set; }
        public DateTime DataNascimento { get; set; }
        public bool Casado { get; set; }
    }
}

Program.cs

using BenchmarkDotNet.Running;

namespace AutoMapperBenchMark
{
    class Program
    {
        static void Main(string[] args)
        {
            BenchmarkRunner.Run<ConversionTest>();
        }
    }
}