private object GetInstanceImpl(Type serviceType, string key, bool onlyShared = false)
{
lock (_registry)
{
// Try to locate matching service entry in the current or a parent container.
ServiceRegistration registration = new ServiceRegistration(serviceType, key);
ServiceEntry entry;
ServiceContainer container;
if (_registry.TryGetValue(registration, out entry))
{
// Service entry found in local registry.
container = this;
}
else
{
// Check parent containers.
container = _parent;
while (container != null)
{
lock (container._registry)
{
if (container._registry.TryGetValue(registration, out entry))
break;
}
container = container._parent;
}
}
if (entry != null)
{
// Resolve instance from service entry.
if (entry.CreationPolicy == CreationPolicy.NonShared)
{
if (onlyShared)
return null;
// Create non-shared (transient) service instance.
var instance = entry.CreateInstance(this);
// Track for disposal, if necessary.
StoreInstance(entry, instance);
return instance;
}
if (entry.CreationPolicy == CreationPolicy.LocalShared && container != this)
{
// Service entry was found in a parent container, but the service is
// configured to be created per container. --> Copy into local registry.
entry = new ServiceEntry(entry);
_registry.Add(registration, entry);
container = this;
}
// Create shared service instance, if not already cached.
// (Double-check to avoid unnecessary lock.)
if (entry.Instances == null)
{
lock (entry)
{
if (entry.Instances == null)
{
var instance = entry.CreateInstance(container);
StoreInstance(entry, instance);
}
}
}
return entry.Instances;
}
}
// The requested service type is not directly registered.
// Other supported types are:
// - IEnumerable<TService> ... service instance collection
// - Func<TService> .......... factory method for lazy resolution
#if !NETFX_CORE && !NET45
if (serviceType.IsGenericType)
#else
if (serviceType.GetTypeInfo().IsGenericType)
#endif
{
var genericType = serviceType.GetGenericTypeDefinition();
if (genericType == typeof(IEnumerable<>))
{
// Requested type is IEnumerable<TService>.
// Get typeof(TService).
#if !NETFX_CORE && !NET45
Type actualServiceType = serviceType.GetGenericArguments()[0];
#else
Type actualServiceType = serviceType.GetTypeInfo().GenericTypeArguments[0];
#endif
// Get array of all named TService instances.
object[] instances = GetAllInstancesImpl(actualServiceType).ToArray();
// Create and fill TService[] array.
Array array = Array.CreateInstance(actualServiceType, instances.Length);
for (int i = 0; i < array.Length; i++)
array.SetValue(instances[i], i);
return array;
}
if (genericType == typeof(Func<>))
{
// Requested type is Func<TService>.
#if !NETFX_CORE && !NET45
var actualServiceType = serviceType.GetGenericArguments()[0];
var factoryFactoryType = typeof(ServiceFactoryFactory<>).MakeGenericType(actualServiceType);
var factoryFactoryInstance = Activator.CreateInstance(factoryFactoryType);
var factoryFactoryMethod = factoryFactoryType.GetMethod("Create");
#else
var actualServiceType = serviceType.GetTypeInfo().GenericTypeArguments[0];
var factoryFactoryType = typeof(ServiceFactoryFactory<>).MakeGenericType(actualServiceType);
var factoryFactoryInstance = Activator.CreateInstance(factoryFactoryType);
var factoryFactoryMethod = factoryFactoryType.GetTypeInfo().GetDeclaredMethod("Create");
#endif
return factoryFactoryMethod.Invoke(factoryFactoryInstance, new object[] { this, key });
}
//if (genericType == typeof(Func<,>) && serviceType.GetGenericArguments()[0] == typeof(string))
//{
// // Requested type is Func<string, TService> where the argument is the name of the service.
// ...
//}
}
return null;
}
/// <summary>
/// Initializes a new instance of the <see cref="ServiceEntry"/> class by copying the settings
/// of an existing service entry.
/// </summary>
/// <param name="entry">The <see cref="ServiceEntry"/> from which to copy the settings.</param>
public ServiceEntry(ServiceEntry entry)
{
CreateInstance = entry.CreateInstance;
CreationPolicy = entry.CreationPolicy;
DisposalPolicy = entry.DisposalPolicy;
}
/// <overloads>
/// <summary>
/// Registers a service.
/// </summary>
/// </overloads>
///
/// <summary>
/// Registers a service using a custom factory method and certain creation and disposal
/// policies.
/// </summary>
/// <param name="serviceType">The type of the service.</param>
/// <param name="key">
/// The name under which the object should be registered. Can be <see langword="null"/> or
/// empty.
/// </param>
/// <param name="createInstance">
/// The factory method responsible for serving the requests from the container.
/// </param>
/// <param name="creationPolicy">
/// The creation policy that specifies when and how a service will be instantiated.
/// </param>
/// <param name="disposalPolicy">
/// The disposal policy that specifies when a service instance will be disposed. (Only
/// relevant if the service instance implements <see cref="IDisposable"/>.)
/// </param>
/// <remarks>
/// If a service with the same type and name is already registered, the existing entry will
/// be replaced.
/// </remarks>
/// <exception cref="ArgumentNullException">
/// <paramref name="serviceType"/> or <paramref name="createInstance"/> is
/// <see langword="null"/>.
/// </exception>
public void Register(Type serviceType, string key, Func<ServiceContainer, object> createInstance, CreationPolicy creationPolicy, DisposalPolicy disposalPolicy)
{
ThrowIfDisposed();
if (serviceType == null)
throw new ArgumentNullException(nameof(serviceType));
if (createInstance == null)
throw new ArgumentNullException(nameof(createInstance));
var registration = new ServiceRegistration(serviceType, key);
var entry = new ServiceEntry(createInstance, creationPolicy, disposalPolicy);
lock (_registry)
{
_registry[registration] = entry;
}
}
/// <summary>
/// Disposes of objects whose lifetime is controlled by the service container.
/// </summary>
/// <param name="entry">The service entry in the registry.</param>
private static void DisposeInstances(ServiceEntry entry)
{
if (entry.DisposalPolicy != DisposalPolicy.Automatic)
return;
if (entry.Instances is IDisposable)
{
// Shared disposable instance.
Debug.Assert(entry.CreationPolicy == CreationPolicy.Shared || entry.CreationPolicy == CreationPolicy.LocalShared);
var instance = (IDisposable)entry.Instances;
instance.Dispose();
}
else if (entry.Instances is WeakReference)
{
// Single non-shared disposable instance.
Debug.Assert(entry.CreationPolicy == CreationPolicy.NonShared);
var instance = ((WeakReference)entry.Instances).Target;
instance.SafeDispose();
}
else if (entry.Instances is WeakCollection<IDisposable>)
{
// Multiple non-shared disposable instance.
Debug.Assert(entry.CreationPolicy == CreationPolicy.NonShared);
var instances = (WeakCollection<IDisposable>)entry.Instances;
foreach (var instance in instances)
instance.Dispose();
}
}
/// <summary>
/// Stores the shared service instance, or keeps track of disposable instances for automatic
/// disposal.
/// </summary>
/// <param name="entry">The service entry in the registry.</param>
/// <param name="instance">The service instance. (Can be <see langword="null"/>.)</param>
private static void StoreInstance(ServiceEntry entry, object instance)
{
if (instance == null)
return;
if (entry.CreationPolicy == CreationPolicy.Shared || entry.CreationPolicy == CreationPolicy.LocalShared)
{
// Store shared instance.
Debug.Assert(entry.Instances == null);
entry.Instances = instance;
}
else
{
// Keep track of non-shared instance for automatic disposal.
Debug.Assert(entry.CreationPolicy == CreationPolicy.NonShared);
if (entry.DisposalPolicy == DisposalPolicy.Automatic)
{
var disposable = instance as IDisposable;
if (disposable != null)
{
if (entry.Instances == null)
{
// This the first service instance.
entry.Instances = new WeakReference(disposable);
}
else if (entry.Instances is WeakReference)
{
// This is the second service instance.
var weakReference = (WeakReference)entry.Instances;
var previousDisposable = (IDisposable)weakReference.Target;
if (previousDisposable == null)
{
// First service instance has already been garbage collected.
weakReference.Target = instance;
}
else
{
// First service instance is still alive.
entry.Instances = new WeakCollection<IDisposable>
{
previousDisposable,
disposable
};
}
}
else if (entry.Instances is WeakCollection<IDisposable>)
{
// Multiple service instance.
var weakCollection = (WeakCollection<IDisposable>)entry.Instances;
weakCollection.Add(disposable);
}
}
}
}
}
/// <summary>
/// Initializes a new instance of the <see cref="ServiceEntry"/> class by copying the settings
/// of an existing service entry.
/// </summary>
/// <param name="entry">The <see cref="ServiceEntry"/> from which to copy the settings.</param>
public ServiceEntry(ServiceEntry entry)
{
CreateInstance = entry.CreateInstance;
CreationPolicy = entry.CreationPolicy;
DisposalPolicy = entry.DisposalPolicy;
}
private object GetInstanceImpl(Type serviceType, string key, bool onlyShared = false)
{
lock (_registry)
{
// Try to locate matching service entry in the current or a parent container.
ServiceRegistration registration = new ServiceRegistration(serviceType, key);
ServiceEntry entry;
ServiceContainer container;
if (_registry.TryGetValue(registration, out entry))
{
// Service entry found in local registry.
container = this;
}
else
{
// Check parent containers.
container = _parent;
while (container != null)
{
lock (container._registry)
{
if (container._registry.TryGetValue(registration, out entry))
{
break;
}
}
container = container._parent;
}
}
if (entry != null)
{
// Resolve instance from service entry.
if (entry.CreationPolicy == CreationPolicy.NonShared)
{
if (onlyShared)
{
return(null);
}
// Create non-shared (transient) service instance.
var instance = entry.CreateInstance(this);
// Track for disposal, if necessary.
StoreInstance(entry, instance);
return(instance);
}
if (entry.CreationPolicy == CreationPolicy.LocalShared && container != this)
{
// Service entry was found in a parent container, but the service is
// configured to be created per container. --> Copy into local registry.
entry = new ServiceEntry(entry);
_registry.Add(registration, entry);
container = this;
}
// Create shared service instance, if not already cached.
// (Double-check to avoid unnecessary lock.)
if (entry.Instances == null)
{
lock (entry)
{
if (entry.Instances == null)
{
var instance = entry.CreateInstance(container);
StoreInstance(entry, instance);
}
}
}
return(entry.Instances);
}
}
// The requested service type is not directly registered.
// Other supported types are:
// - IEnumerable<TService> ... service instance collection
// - Func<TService> .......... factory method for lazy resolution
#if !NETFX_CORE && !NET45
if (serviceType.IsGenericType)
#else
if (serviceType.GetTypeInfo().IsGenericType)
#endif
{
var genericType = serviceType.GetGenericTypeDefinition();
if (genericType == typeof(IEnumerable <>))
{
// Requested type is IEnumerable<TService>.
// Get typeof(TService).
#if !NETFX_CORE && !NET45
Type actualServiceType = serviceType.GetGenericArguments()[0];
#else
Type actualServiceType = serviceType.GetTypeInfo().GenericTypeArguments[0];
#endif
// Get array of all named TService instances.
object[] instances = GetAllInstancesImpl(actualServiceType).ToArray();
// Create and fill TService[] array.
Array array = Array.CreateInstance(actualServiceType, instances.Length);
for (int i = 0; i < array.Length; i++)
{
array.SetValue(instances[i], i);
}
return(array);
}
if (genericType == typeof(Func <>))
{
// Requested type is Func<TService>.
#if !NETFX_CORE && !NET45
var actualServiceType = serviceType.GetGenericArguments()[0];
var factoryFactoryType = typeof(ServiceFactoryFactory <>).MakeGenericType(actualServiceType);
var factoryFactoryInstance = Activator.CreateInstance(factoryFactoryType);
var factoryFactoryMethod = factoryFactoryType.GetMethod("Create");
#else
var actualServiceType = serviceType.GetTypeInfo().GenericTypeArguments[0];
var factoryFactoryType = typeof(ServiceFactoryFactory <>).MakeGenericType(actualServiceType);
var factoryFactoryInstance = Activator.CreateInstance(factoryFactoryType);
var factoryFactoryMethod = factoryFactoryType.GetTypeInfo().GetDeclaredMethod("Create");
#endif
return(factoryFactoryMethod.Invoke(factoryFactoryInstance, new object[] { this, key }));
}
//if (genericType == typeof(Func<,>) && serviceType.GetGenericArguments()[0] == typeof(string))
//{
// // Requested type is Func<string, TService> where the argument is the name of the service.
// ...
//}
}
return(null);
}