/// <summary>
/// Initializes a new instance of the <see cref="IxSingletonInstance"/> class.
/// </summary>
/// <param name="providerNode">Singleton provider.</param>
/// <param name="parentInstance">Parent instance.</param>
/// <param name="context">The resolve context.</param>
/// <param name="frame">The resolution frame in the resolve sequence.</param>
/// <param name="creatorTempLock">First temp lock for the creator of a new instance.</param>
public IxSingletonInstance(
IxSingletonProvider providerNode,
IIxInstance parentInstance,
IxHost.IxResolveContext context,
[CanBeNull] IxResolveFrame frame,
out IIxInstanceLock creatorTempLock)
: base(providerNode, parentInstance, out creatorTempLock)
{
if (parentInstance == null)
{
throw new ArgumentNullException(nameof(parentInstance));
}
if (context == null)
{
throw new ArgumentNullException(nameof(context));
}
Debug.Assert(ProviderNode.InstanceFactory != null, "IxSingletonProvider always have instance factory.");
var newFrame = new IxResolveFrame(frame, this);
SetObjectCreationTask(
ProviderNode.InstanceFactory.Factory(
this,
parentInstance,
context,
newFrame));
}
#pragma warning disable CS1998 // Async method lacks 'await' operators and will run synchronously
/// <inheritdoc/>
public override async ValueTask <IIxInstanceLock> GetInstance(
IIxInstance parentInstance,
IxIdentifier identifier,
IxHost.IxResolveContext context,
[CanBeNull] IxResolveFrame frame)
{
if (parentInstance == null)
{
throw new ArgumentNullException(nameof(parentInstance));
}
lock (Host.InstanceTreeSyncRoot)
{
IIxInstanceLock scopeLock;
IxScopeInstance singleton;
object data = parentInstance.GetData(this);
if (data == null)
{
singleton = new IxScopeInstance(this, parentInstance, out scopeLock);
parentInstance.SetData(this, singleton);
}
else
{
singleton = (IxScopeInstance)data;
scopeLock = new IxInstancePinLock(singleton);
}
return(scopeLock);
}
}
public override ValueTask <IIxInstanceLock> GetInstance(
IIxInstance parentInstance,
IxIdentifier identifier,
IxHost.IxResolveContext context,
[CanBeNull] IxResolveFrame frame)
{
throw new NotImplementedException();
}
/// <inheritdoc/>
public override async ValueTask <IIxInstanceLock> GetInstance(
IIxInstance parentInstance,
IxIdentifier identifier,
IxHost.IxResolveContext context,
[CanBeNull] IxResolveFrame frame)
{
Critical.Assert(false, "Not supported.");
return(null);
}
/// <inheritdoc/>
public override async ValueTask <IIxInstanceLock> GetInstance(
IIxInstance parentInstance,
IxIdentifier identifier,
IxHost.IxResolveContext context,
[CanBeNull] IxResolveFrame frame)
{
if (parentInstance == null)
{
throw new ArgumentNullException(nameof(parentInstance));
}
if (context == null)
{
throw new ArgumentNullException(nameof(context));
}
IIxInstanceLock creatorLock = null;
IxSingletonInstance instance;
// Re-implement this with more advanced Half-Instantiation with loop detection.
lock (Host.InstanceTreeSyncRoot)
{
instance = parentInstance.GetData(this) as IxSingletonInstance;
if (instance == null)
{
// TODO: Detect cycles.
Debug.Assert(InstanceFactory != null, "InstanceFactory != null");
instance = new IxSingletonInstance(this, parentInstance, context, frame, out creatorLock);
parentInstance.SetData(this, instance);
}
}
try
{
await instance.ObjectCreationTask;
return(creatorLock ?? new IxInstancePinLock(instance));
}
catch
{
if (creatorLock != null)
{
lock (Host.InstanceTreeSyncRoot)
{
parentInstance.SetData(this, null);
}
creatorLock.Dispose();
}
throw;
}
}
/// <summary>
/// Tries to get argument value for the provided identifier.
/// </summary>
/// <param name="identifier">Argument identifier.</param>
/// <param name="context">The resolve context.</param>
/// <returns>Argument instance lock or null, if no argument found for the provided identifier.</returns>
public IIxInstanceLock TryGetInstance(IxIdentifier identifier, IxHost.IxResolveContext context)
{
IxHost.IxResolveContext curContext = context;
while (curContext != null)
{
if (context.Arguments.TryGetValue(identifier, out var result))
{
return(new IxInstancePinLock(new IxArgumentInstance(this, result)));
}
curContext = context.ParentContext;
}
// ReSharper disable once AssignNullToNotNullAttribute
return(null);
}
public abstract ValueTask <IIxInstanceLock> GetInstance(
IIxInstance parentInstance,
IxIdentifier identifier,
IxHost.IxResolveContext context,
[CanBeNull] IxResolveFrame frame);