Niubility.LightDataAccess

EmitMapper

Project Description

What is EmitMapper

EmitMapper is a small library for parsing object-object clones, typically used to convert data objects into domain objects and vice versa.

Powerful customizable tool for mapping entities to each other. Entities can be plain objects, DataReaders, SQL commands and anything you need. The tool uses run-time code generation via the Emit library. It is useful for dealing with DTO objects, data access layers an so on.

How do I get started?

    var simple = Mapper.Default.GetMapper<BenchNestedSource, BenchNestedDestination>();
    BenchNestedDestination dest = simple.Map(_benchSource); //for single object;
    List<BenchNestedDestination> dests = simple.MapEnum(_benchSources1000List);// for list object

Supported platforms:

• NETStandard 2.1
• .Net Framework 4.8
• net 6.0
• netcore app 3.1

Where can I get it?

First, install NuGet. Then, install EmitMapper from the package manager console:

Install-Package Niubility.EmitMapper

About Emit Mapper

• Overview
• Benefits of EmitMapper
• Getting started
• Type conversion
• Customization

Customization overview

Customization using default configurator

• Default configurator overview
• Custom converters
• Custom converters_for_generics
• Null substitution
• Ignoring members
• Custom constructors
• Shallow and_deep_mapping
• Names matching
• Post processing

Low-level customization using custom configuratorors

Emit Mapper in practice.

• Benchmark: EmitMapper vs Handwritten code vs AutoMapper
• Objects change tracking
• Mapping DbDatareader to objects
• Mapping objects to DbCommand (UPDATE and INSERT) Last edited Jan 11, 2010 at 3:01 PM by romankovs

Benchmark

BenchmarkDotNet=v0.13.1, OS=Windows 10.0.18363.2037 (1909/November2019Update/19H2)
Intel Core i5-8350U CPU 1.70GHz (Kaby Lake R), 1 CPU, 8 logical and 4 physical cores
.NET SDK=6.0.101
  [Host]   : .NET 6.0.1 (6.0.121.56705), X64 RyuJIT
  .NET 6.0 : .NET 6.0.1 (6.0.121.56705), X64 RyuJIT
Job=.NET 6.0  Runtime=.NET 6.0  

Method	Mean	Error	StdDev	Median	Ratio	Gen 0	Gen 1	Allocated
BenchNested_a_HardMapper	0.8563 ns	0.0173 ns	0.0341 ns	0.8489 ns	1.00	0.0010	-	3 B
BenchNested_b_EmitMapper	0.8897 ns	0.0431 ns	0.1264 ns	0.8451 ns	1.00	0.0010	-	3 B
BenchNested_c_AutoMapper	16.5678 ns	0.7823 ns	2.2945 ns	16.7384 ns	1.00	0.0009	-	3 B
BenchNested1000_a_HardMapper	3,988.9549 ns	79.6474 ns	97.8142 ns	3,965.5109 ns	1.00	0.4766	0.2344	3,024 B
BenchNested1000_b_EmitMapper	3,781.9851 ns	74.5756 ns	122.5298 ns	3,776.3773 ns	1.00	0.4766	0.2344	3,024 B
BenchNested1000_c_AutoMapper	16,978.1985 ns	333.1485 ns	396.5896 ns	16,966.0594 ns	1.00	0.4688	0.2188	3,033 B
SimpleTypes_a_HardMapper	0.0310 ns	0.0008 ns	0.0023 ns	0.0307 ns	1.00	0.0000	-	-
SimpleTypes_b_EmitMapper	0.0512 ns	0.0009 ns	0.0010 ns	0.0513 ns	1.00	0.0000	-	-
SimpleTypes_c_AutoMapper	0.1718 ns	0.0035 ns	0.0076 ns	0.1709 ns	1.00	0.0000	-	-
SimpleTypes100_a_HardMapper	4.0774 ns	0.0804 ns	0.1714 ns	4.0509 ns	1.00	0.0041	-	13 B
SimpleTypes100_b_EmitMapper	8.4392 ns	0.4806 ns	1.4020 ns	8.3280 ns	1.00	0.0044	-	14 B
SimpleTypes100_c_AutoMapper	8.4149 ns	0.5269 ns	1.5285 ns	8.0763 ns	1.00	0.0045	-	14 B
SimpleTypes1000_a_HardMapper	53.3382 ns	1.0229 ns	2.8684 ns	52.6775 ns	1.00	0.0320	0.0103	128 B
SimpleTypes1000_b_EmitMapper	81.6188 ns	1.9400 ns	5.5036 ns	79.9001 ns	1.00	0.0308	0.0101	128 B
SimpleTypes1000_c_AutoMapper	89.3916 ns	4.3419 ns	12.6655 ns	86.0168 ns	1.00	0.0369	0.0082	137 B

Changelog

• Feb 8, 2022 The newest benchmark test is shown that the performance problem has been resolved. to see the method ToInt32(decimal?) of class NullableConverter
• Add github action for publish the package to nuget.org automatically