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VContainer

The extra fast DI (Dependency Injection) for Unity Game Engine. "V" means making Unity's initial "U" more thinner and solid..!

  • Fast Resolve: Basically 5-10x faster than Zenject.
  • Minimum GC Allocation: In Resolve, we have zero allocation without spawned instances.
  • Small code size: Few internal types and few .callvirt.
  • Assisting correct DI way: Provides simple and transparent API, and carefully select features. This prevents the DI declaration from becoming overly complex.
  • Immutable Container: Thread safety and robustness.

Features#

DI + Inversion of Control for Unity#

DI containers we can make pure C # classes the entry point (not MonoBehaviour). This means that the control flow and other domain logic can be separated from the function of MonoBehaviour as a view component.

Further reading:

Performance#

Benchmark result for 10,000 iterations for each test case (Unity 2019.x / IL2CPP Standalone macOS)#

  • By default, both VContainer and Zenject use reflection at runtime.
  • "VContainer (CodeGen)" means optimization by pre-generating IL code of Inject methods by ILPostProcessor. See Optimization section for more information.

GC Alloc result in the Resolve Complex test case (Unity Editor profiled)#

Basic Usage#

First, create a scope. References are automatically resolved for types registered here.

public class GameLifetimeScope : LifetimeScope{    public override void Configure(IContainerBuilder builder)    {        builder.RegisterEntryPoint<ActorPresenter>();
        builder.Register<CharacterService>(Lifetime.Scoped);        builder.Register<IRouteSearch, AStarRouteSearch>(Lifetime.Singleton);
        builder.RegisterComponentInHierarchy<ActorsView>();    }}

Where definitions of classes are

public interface IRouteSearch{}
public class AStarRouteSearch : IRouteSearch{}
public class CharacterService{    readonly IRouteSearch routeSearch;
    public CharacterService(IRouteSearch routeSearch)    {        this.routeSearch = routeSearch;    }}
public class ActorsView : MonoBehaviour{}

and

public class ActorPresenter : IStartable{    readonly CharacterService service;    readonly ActorsView actorsView;
    public ActorPresenter(        CharacterService service,        ActorsView actorsView)    {        this.service = service;        this.actorsView = actorsView;    }
    void IStartable.Start()    {        // Scheduled at Start () on VContainer's own PlayerLoopSystem.    }}
  • In this example, the routeSearch of CharacterService is automatically set as the instance of AStarRouteSearch when CharacterService is resolved.
  • Further, VContainer can have a Pure C# class as an entry point. (Various timings such as Start, Update, etc. can be specified.) This facilitates "separation of domain logic and presentation".

Flexible Scoping with async#

LifetimeScope can dynamically create children. This allows you to deal with the asynchronous resource loading that often occurs in games.

public void LoadLevel(){    // ... Loading some assets
    // Create a child scope    instantScope = currentScope.CreateChild();
    // Create a child scope with LifetimeScope prefab    instantScope = currentScope.CreateChildFromPrefab(lifetimeScopePrefab);
    // Create a child with additional registration    instantScope = currentScope.CreateChildFromPrefab(        lifetimeScopePrefab,        builder =>        {            // Extra Registrations ...        });
    instantScope = currentScope.CreateChild(builder =>    {        // ExtraRegistrations ...    });
    instantScope = currentScope.CreateChild(extraInstaller);}
public void UnloadLevel(){    instantScope.Dispose();}

In addition, you can create a parent-child relationship with LifetimeScope in an Additive scene.

class SceneLoader{    readonly LifetimeScope currentScope;
    public SceneLoader(LifetimeScope currentScope)    {        currentScope = currentScope; // Inject the LifetimeScope to which this class belongs    }
    IEnumerator LoadSceneAsync()    {        // LifetimeScope generated in this block will be parented by `this.lifetimeScope`        using (LifetimeScope.EnqueueParent(currentScope))        {            // If this scene has a LifetimeScope, its parent will be `parent`.            var loading = SceneManager.LoadSceneAsync("...", LoadSceneMode.Additive);            while (!loading.isDone)            {                yield return null;            }        }    }
    // UniTask example    async UniTask LoadSceneAsync()    {        using (LifetimeScope.EnqueueParent(parent))        {            await SceneManager.LoadSceneAsync("...", LoadSceneMode.Additive);        }    }}
// LifetimeScopes generated during this block will be additionally Registered.using (LifetimeScope.Enqueue(builder =>{    // Register for the next scene not yet loaded    builder.RegisterInstance(extraInstance);})){    // Loading the scene..}

See scoping for more information.

UniTask#

public class FooController : IAsyncStartable{    public async UniTask StartAsync(CancellationToken cancellation)    {        await LoadSomethingAsync(cancellation);        await ...        ...    }}
builder.RegisterEntryPoint<FooController>();

See integration for more information.

Diagnostics Window#

See diagnostics for more information.

Getting Started#