Lazy injection for Unity container

A LazyProxy can be used for IoC containers to change the resolving behaviour.

Dependencies registered as lazy are created as dynamic proxy objects built in real time, but the real classes are resolved only after the first execution of proxy method or property.

Also dynamic lazy proxy allows injection of circular dependencies.

var container = new UnityContainer().RegisterLazy<IMyService, MyService>();

Console.WriteLine("Resolving service...");
var service = container.Resolve<IMyService>();

Console.WriteLine("Foo execution...");
service.Foo();

// Resolving service...
// Foo execution...
// Hello from ctor
// Hello from Foo

The following is supported:

• Registration of types by interfaces;
• Passing lifetime managers;
• Passing injection members;
• Resolving by child containers.

Not supported yet:

• Registration of instances.

Performance

Here is a result of the Benchmark test

BenchmarkDotNet=v0.10.14, OS=Windows 10.0.17134
Intel Core i5-6600K CPU 3.50GHz (Skylake), 1 CPU, 4 logical and 4 physical cores
Frequency=3421881 Hz, Resolution=292.2369 ns, Timer=TSC
.NET Core SDK=2.1.104
  [Host]     : .NET Core 2.0.6 (CoreCLR 4.6.26212.01, CoreFX 4.6.26212.01), 64bit RyuJIT
  Job-WRIASW : .NET Framework 4.7.1 (CLR 4.0.30319.42000), 64bit RyuJIT-v4.7.3131.0
  Job-AHTPGH : .NET Core 2.0.6 (CoreCLR 4.6.26212.01, CoreFX 4.6.26212.01), 64bit RyuJIT

InvocationCount=1  LaunchCount=10  RunStrategy=ColdStart  TargetCount=1 
  

                     Method | Runtime |        Mean |        Error |      StdDev |
--------------------------- |-------- |------------:|-------------:|------------:|
               RegisterType |     Clr |  4,137.7 us |    413.30 us |   273.37 us |
               RegisterLazy |     Clr | 20,674.2 us |  8,720.50 us | 5,768.07 us |
            ColdResolveType |     Clr | 46,964.2 us |  7,248.30 us | 4,794.30 us |
            ColdResolveLazy |     Clr | 45,114.7 us | 14,851.68 us | 9,823.47 us |
             HotResolveType |     Clr | 11,071.5 us |    537.94 us |   355.81 us |
             HotResolveLazy |     Clr |    459.6 us |     81.59 us |    53.97 us |
               InvokeMethod |     Clr |    360.1 us |    104.89 us |    69.38 us |
  InvokeLazyMethodFirstTime |     Clr | 16,164.2 us |    725.08 us |   479.60 us |
 InvokeLazyMethodSecondTime |     Clr |    315.4 us |     53.41 us |    35.33 us |
               RegisterType |    Core |  3,687.9 us |    395.56 us |   261.64 us |
               RegisterLazy |    Core | 17,750.2 us |  7,664.41 us | 5,069.54 us |
            ColdResolveType |    Core | 50,519.3 us |  2,217.58 us | 1,466.79 us |
            ColdResolveLazy |    Core | 46,829.4 us |  1,848.44 us | 1,222.63 us |
             HotResolveType |    Core | 10,911.2 us |    542.79 us |   359.02 us |
             HotResolveLazy |    Core |    471.4 us |     47.37 us |    31.34 us |
               InvokeMethod |    Core |    333.8 us |     23.26 us |    15.39 us |
  InvokeLazyMethodFirstTime |    Core | 16,226.2 us |    527.92 us |   349.18 us |
 InvokeLazyMethodSecondTime |    Core |    336.4 us |     68.45 us |    45.28 us |

// * Legends *
  Mean   : Arithmetic mean of all measurements
  Error  : Half of 99.9% confidence interval
  StdDev : Standard deviation of all measurements
  1 us   : 1 Microsecond (0.000001 sec)

License

This project is licensed under the Apache License, Version 2.0. - see the LICENSE file for details.