Performance test for AutoMapper

[hippieZhou]

when I use AutoMapper to map my entities, I'm having performance question.so I'm going to use BenchmarkDotNet with console app for a pressure measurement.The results did not live up to expectations.what should i do?

Env

• OS：Windows 10.0.19042.1348 (20H2/October2020Update)
• CPU：Intel Core i5-7500 CPU 3.40GHz (Kaby Lake), 1 CPU, 4 logical and 4 physical cores
• SDK：NET SDK=6.0.100

Packages

• BenchmarkDotNet --version 0.13.1
• AutoMapper --version 10.1.1
• Mapster --version 7.2.0

Source/destination types

public enum MyEnum
{
    [Description("进行中")]
    Doing,
    [Description("完成")]
    Done
}

//  source types 
public class Entity
{
    public int Id { get; set; }
    public Guid Oid { get; set; }
    public string? NickName { get; set; }
    public bool Created { get; set; }
    public MyEnum State { get; set; }
}

// destination type
public class EntityDto
{
    public int Id { get; set; }
    public Guid Oid { get; set; }
    public string? NickName { get; set; }
    public bool Created { get; set; }
    public MyEnum Enum { get; set; }
    public string? EnumString { get; set; }
}

Mapping configuration

//  AutoMapper profile
public class AutoMapperProfile : Profile
{
    public AutoMapperProfile()
    {
        CreateMap<Entity, EntityDto>()
                .ForMember(dest => dest.Id, opt => opt.MapFrom(src => src.Id))
                .ForMember(dest => dest.Oid, opt => opt.MapFrom(src => src.Oid))
                .ForMember(dest => dest.NickName, opt => opt.MapFrom(src => src.NickName))
                .ForMember(dest => dest.Created, opt => opt.MapFrom(src => src.Created))
                .ForMember(dest => dest.Enum, opt => opt.MapFrom(src => src.State))
                .ForMember(dest => dest.EnumString, opt => opt.MapFrom(src => src.State.GetDescription()));
    }
}

// Mapster profile
public class MapsterProfile : TypeAdapterConfig
{
    public MapsterProfile()
    {
        ForType<Entity, EntityDto>()
                .Map(dest => dest.Id, src => src.Id)
                .Map(dest => dest.Oid, src => src.Oid)
                .Map(dest => dest.NickName, src => src.NickName)
                .Map(dest => dest.Created, src => src.Created)
                .Map(dest => dest.Enum, src => src.State)
                .Map(dest => dest.EnumString, src => src.State.GetDescription());
    }
}

Test Code

_entities = Enumerable.Range(0, 1000000).Select(x => mocker.CreateInstance<Entity>()).ToList();

[Benchmark]
public void Constructor()
{
    var dtos = _entities.Select(x => new EntityDto
    {
        Id = x.Id,
        Oid = x.Oid,
        NickName = x.NickName,
        Created = x.Created,
        Enum = x.State,
        EnumString = x.State.GetDescription(),
    });
}

[Benchmark]
public void AutoMapper()
{
    var conf = new AutoMapper.MapperConfiguration(cfg => cfg.AddProfile<AutoMapperProfile>());
    var mapper = conf.CreateMapper();
    var dtos = mapper.Map<IEnumerable<EntityDto>>(_entities);

}
[Benchmark]
public void Mapster()
{
    var conf = new MapsterMapper.Mapper(new MapsterProfile());
    var dtos = conf.Map<IEnumerable<EntityDto>>(_entities);
}

Actual behavior

How I should improve performance ?

[jbogard]

Only Mapper.Map should be in the benchmark. Everything else is one-time setup code, for both libraries.

…

On Nov 22, 2021, at 8:33 PM, hippie ***@***.***> wrote:  when I use AutoMapper to map my entities, I'm having performance question.so I'm going to use BenchmarkDotNet with console app for a pressure measurement.The results did not live up to expectations.what should i do? Env OS：Windows 10.0.19042.1348 (20H2/October2020Update) CPU：Intel Core i5-7500 CPU 3.40GHz (Kaby Lake), 1 CPU, 4 logical and 4 physical cores SDK：NET SDK=6.0.100 Packages BenchmarkDotNet --version 0.13.1 AutoMapper --version 10.1.1 Mapster --version 7.2.0 Source/destination types public enum MyEnum { [Description("进行中")] Doing, [Description("完成")] Done } // source types public class Entity { public int Id { get; set; } public Guid Oid { get; set; } public string? NickName { get; set; } public bool Created { get; set; } public MyEnum State { get; set; } } // destination type public class EntityDto { public int Id { get; set; } public Guid Oid { get; set; } public string? NickName { get; set; } public bool Created { get; set; } public MyEnum Enum { get; set; } public string? EnumString { get; set; } } Mapping configuration // AutoMapper profile public class AutoMapperProfile : Profile { public AutoMapperProfile() { CreateMap<Entity, EntityDto>() .ForMember(dest => dest.Id, opt => opt.MapFrom(src => src.Id)) .ForMember(dest => dest.Oid, opt => opt.MapFrom(src => src.Oid)) .ForMember(dest => dest.NickName, opt => opt.MapFrom(src => src.NickName)) .ForMember(dest => dest.Created, opt => opt.MapFrom(src => src.Created)) .ForMember(dest => dest.Enum, opt => opt.MapFrom(src => src.State)) .ForMember(dest => dest.EnumString, opt => opt.MapFrom(src => src.State.GetDescription())); } } // Mapster profile public class MapsterProfile : TypeAdapterConfig { public MapsterProfile() { ForType<Entity, EntityDto>() .Map(dest => dest.Id, src => src.Id) .Map(dest => dest.Oid, src => src.Oid) .Map(dest => dest.NickName, src => src.NickName) .Map(dest => dest.Created, src => src.Created) .Map(dest => dest.Enum, src => src.State) .Map(dest => dest.EnumString, src => src.State.GetDescription()); } } Test Code _entities = Enumerable.Range(0, 1000000).Select(x => mocker.CreateInstance<Entity>()).ToList(); [Benchmark] public void Constructor() { var dtos = _entities.Select(x => new EntityDto { Id = x.Id, Oid = x.Oid, NickName = x.NickName, Created = x.Created, Enum = x.State, EnumString = x.State.GetDescription(), }); } [Benchmark] public void AutoMapper() { var conf = new AutoMapper.MapperConfiguration(cfg => cfg.AddProfile<AutoMapperProfile>()); var mapper = conf.CreateMapper(); var dtos = mapper.Map<IEnumerable<EntityDto>>(_entities); } [Benchmark] public void Mapster() { var conf = new MapsterMapper.Mapper(new MapsterProfile()); var dtos = conf.Map<IEnumerable<EntityDto>>(_entities); } Actual behavior How I should improve performance ? — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub, or unsubscribe.

[hippieZhou]

I clean up my code and then retest them

public class PerformanceTest
{
    private IReadOnlyList<Entity> _entities;
    private readonly AutoMapper.IMapper _autoMapper;
    private readonly Mapper _mapsterMapper;

    public PerformanceTest()
    {
        var mocker = new AutoMocker();
        _entities = Enumerable.Range(0, 1000000).Select(x => mocker.CreateInstance<Entity>()).ToList();

        _autoMapper = new AutoMapper.MapperConfiguration(cfg => cfg.AddProfile<AutoMapperProfile>()).CreateMapper();
        _mapsterMapper = new MapsterMapper.Mapper(new MapsterProfile());
    }

    [Benchmark]
    public void Constructor()
    {
        var dtos = _entities.Select(x => new EntityDto
        {
            Id = x.Id,
            Oid = x.Oid,
            NickName = x.NickName,
            Created = x.Created,
            Enum = x.State,
            EnumString = x.State.GetDescription(),
        });
    }

    [Benchmark]
    public void AutoMapper()
    {
        var dtos = _autoMapper.Map<IEnumerable<EntityDto>>(_entities);

    }
    [Benchmark]
    public void Mapster()
    {
        var dtos = _mapsterMapper.Map<IEnumerable<EntityDto>>(_entities);
    }
}

[lbargaoanu]

The first four MapFroms are useless. Also, try the MyGet build. Check the execution plan.
Then, as @jbogard says, split the config and the mapping stages, and use a profiler to see where time is spent.
But, your code aside, check the existing benchmark. On a slow laptop, I can map a million objects in a few hundred milliseconds. That should be fast enough for most applications.

[lbargaoanu]

The problem must be with your own code. Run the existing benchmark and you'll get very different results :)

[lbargaoanu]

Did you use the MyGet build as I requested? Your test probably just reflects compilation time, not the mapping itself. See #3753 for example.