Mappee - Fastest avaiable mapper for .NET

Mappee is a high performance object-to-object mapper for .NET. It is a simple and easy to use library that can be used to map objects of different types. It is designed to be fast and efficient, and it is the fastest available mapper for .NET. The main idea is to map objects using precompiled code, which makes it much faster than other mappers that use reflection. Generated code is cached, so it is only generated once for each type pair, and then reused for all subsequent mappings.

Features

• Fast and efficient
• Simple and easy to use

Getting Started

Using static methods

Mapper.Bind<TestObject, TestObjectDto>()
    .IgnoreMember<TestObject, TestObjectDto>(e => e.Name);
    .BeforeMap<TestObject, TestObjectDto>((source, _) =>
    {
        source.Nickname = $"{source.FirstName}{source.LastName}".ToLower();
    })
    .AfterMap<TestObject, TestObjectDto>((_, destination) =>
    {
        destination.Char = destination.FirstName.First();
    })
    .Bind<TestObjectModification, TestObjectModificationDto>()
    .Bind<TestObjectField, TestObjectFieldDto>()
    .Bind<TestObjectLink, TestObjectLinkDto>()
    .Compile();

var testObject = new TestObject();

var testObjectDto = Mapper.Map<TestObjectDto>(testObject);

Using dependency injection

var servicesCollection = new ServiceCollection();
servicesCollection.AddMappee(profile =>
{
    profile.Bind<TestObject, TestObjectDto>()
        .IgnoreMember<TestObject, TestObjectDto>(e => e.Name)
        .BeforeMap<TestObject, TestObjectDto>((source, _) =>
        {
            source.Nickname = $"{source.FirstName}{source.LastName}".ToLower();
        })
        .AfterMap<TestObject, TestObjectDto>((_, destination) =>
        {
            destination.Char = destination.FirstName.First();
        });

    //invoke compile method is not necessary, it will be called automatically
});

//[...]

var serviceProvider = servicesCollection.BuildServiceProvider();
var scope = serviceProvider.CreateScope();

var mapper = scope.ServiceProvider.GetRequiredService<IMapper>();

var testObject = new TestObject();
var testObjectDto = mapper.Map<TestObject, TestObjectDto>(testObject);

Mappee vs other mappers (performance comparison)

Benchmarks

2500 items in 3 different collections and 2500 nested objects (like linked list)

BenchmarkDotNet v0.13.12, Windows 11 (10.0.22631.3155/23H2/2023Update/SunValley3)
12th Gen Intel Core i7-12700K, 1 CPU, 20 logical and 12 physical cores
.NET SDK 8.0.101
  [Host]   : .NET 8.0.1 (8.0.123.58001), X64 RyuJIT AVX2
  .NET 8.0 : .NET 8.0.1 (8.0.123.58001), X64 RyuJIT AVX2

Job=.NET 8.0  Runtime=.NET 8.0  

Method	Items	Mean	Error	StdDev	Ratio	Rank	Gen0	Gen1	Gen2	Allocated	Alloc Ratio
AutoMapper	2500	1,697.0 μs	33.92 μs	58.50 μs	1.00	1	144.5313	142.5781	35.1563	1.5 MB	1.00
TinyMapper	2500	426.8 μs	1.94 μs	1.82 μs	1.00	1	99.1211	49.3164	-	1.24 MB	1.00
Mappee	2500	268.0 μs	2.85 μs	2.67 μs	1.00	1	140.6250	93.2617	-	1.75 MB	1.00
Handwritten	2500	233.5 μs	4.08 μs	3.62 μs	1.00	1	122.0703	66.4063	-	1.52 MB	1.00

---

1,5,20 items in 3 different collections and 1,5,20 nested objects (like linked list)

BenchmarkDotNet v0.13.12, Windows 11 (10.0.22631.3155/23H2/2023Update/SunValley3)
12th Gen Intel Core i7-12700K, 1 CPU, 20 logical and 12 physical cores
.NET SDK 8.0.101
  [Host]   : .NET 8.0.1 (8.0.123.58001), X64 RyuJIT AVX2
  .NET 8.0 : .NET 8.0.1 (8.0.123.58001), X64 RyuJIT AVX2

Job=.NET 8.0  Runtime=.NET 8.0  

Method	Items	Mean	Error	StdDev	Ratio	Rank	Gen0	Gen1	Allocated	Alloc Ratio
AutoMapper	5	928.6 ns	12.45 ns	11.64 ns	1.00	1	0.2775	0.0029	3.55 KB	1.00
TinyMapper	5	930.4 ns	9.43 ns	8.82 ns	1.00	1	0.2356	0.0019	3.01 KB	1.00
Mappee	5	457.6 ns	9.17 ns	10.56 ns	1.00	1	0.3252	0.0029	4.16 KB	1.00
Handwritten	5	368.8 ns	1.90 ns	1.58 ns	1.00	1	0.2813	0.0024	3.59 KB	1.00
AutoMapper	10	1,663.7 ns	14.35 ns	13.42 ns	1.00	1	0.5302	0.0095	6.79 KB	1.00
TinyMapper	10	1,708.8 ns	18.58 ns	17.38 ns	1.00	1	0.4387	0.0057	5.6 KB	1.00
Mappee	10	832.1 ns	13.57 ns	12.70 ns	1.00	1	0.6113	0.0095	7.8 KB	1.00
Handwritten	10	683.4 ns	5.36 ns	4.75 ns	1.00	1	0.5302	0.0076	6.77 KB	1.00
AutoMapper	20	3,082.1 ns	13.87 ns	12.30 ns	1.00	1	1.0376	0.0343	13.26 KB	1.00
TinyMapper	20	3,334.9 ns	65.42 ns	77.87 ns	1.00	1	0.8392	0.0229	10.72 KB	1.00
Mappee	20	1,575.2 ns	31.47 ns	52.58 ns	1.00	1	1.1768	0.0343	15.03 KB	1.00
Handwritten	20	1,313.9 ns	15.95 ns	14.14 ns	1.00	1	1.0223	0.0286	13.06 KB	1.00

Supported platforms

• .NET 8.0
• .NET 7.0
• .NET 6.0
• .NET Standard 2.1
• .NET Standard 2.0
• .NET Framework 4.8.1