/// <summary>
/// Initializes a new instance of the <see cref="ServiceVertex"/> class.
/// </summary>
/// <param name="service">The service.</param>
public ServiceVertex(KernelService service)
{
{
Debug.Assert(service != null, "The service should exist");
}
Service = service;
}
/// <summary>
/// Initializes a new instance of the <see cref="ServiceVertex"/> class.
/// </summary>
/// <param name="service">The service.</param>
public ServiceVertex(KernelService service)
{
{
Debug.Assert(service != null, "The service should exist");
}
Service = service;
}
/// <summary>
/// Initializes a new instance of the <see cref="ConnectionMap"/> class.
/// </summary>
/// <param name="requestedType">Type of the requested service.</param>
/// <param name="appliedType">Type of the applied service.</param>
public ConnectionMap(Type requestedType, KernelService appliedType)
{
{
Debug.Assert(requestedType != null, "A requested type must be provided.");
Debug.Assert(appliedType != null, "An applied type must be provided.");
}
Requested = requestedType;
Applied = appliedType;
}
/// <summary>
/// Initializes a new instance of the <see cref="ConnectionMap"/> class.
/// </summary>
/// <param name="requestedType">Type of the requested service.</param>
/// <param name="appliedType">Type of the applied service.</param>
public ConnectionMap(Type requestedType, KernelService appliedType)
{
{
Debug.Assert(requestedType != null, "A requested type must be provided.");
Debug.Assert(appliedType != null, "An applied type must be provided.");
}
Requested = requestedType;
Applied = appliedType;
}
/// <summary>
/// Gets the dependency services that are currently available based on the given collection of dependencies.
/// </summary>
/// <param name="demandedServices">The collection of types which should be matched up with the installed services.</param>
/// <returns>
/// A collection containing a mapping between the demanded dependency and the service that would
/// serve for this dependency.
/// </returns>
/// <design>
/// Note that the current connection strategy only works if there are no demands for duplicates OR
/// services with the same interfaces.
/// </design>
private IEnumerable <KeyValuePair <Type, KernelService> > GetInstalledDependencies(IEnumerable <Type> demandedServices)
{
// Create a copy of the available service list. Then when we
// select a service we'll remove it from this list.
var available = new List <KernelService>(from service in m_Services select service.Value);
// Dependencies have just gotten a whole lot more complex
// We want to be able to match up interfaces & abstract classes too
// The problem is that we only want to pass each service only once
var result = new List <KeyValuePair <Type, KernelService> >();
foreach (var dependency in demandedServices)
{
KernelService selected = null;
foreach (var storedService in available)
{
if (dependency.IsAssignableFrom(storedService.GetType()))
{
selected = storedService;
break;
}
}
if (selected != null)
{
available.Remove(selected);
result.Add(new KeyValuePair <Type, KernelService>(dependency, selected));
}
if (available.Count == 0)
{
break;
}
}
return(result);
}
/// <summary>
/// Provides one of the services on which the current service depends.
/// </summary>
/// <param name="dependency">The dependency service.</param>
public virtual void ConnectTo(KernelService dependency)
{
// Do nothing here ...
}
/// <summary>
/// Resets this instance.
/// </summary>
internal void Reset()
{
m_Connection = null;
}
/// <summary>
/// Provides one of the services on which the current service depends.
/// </summary>
/// <param name="dependency">The dependency service.</param>
public override void ConnectTo(KernelService dependency)
{
m_Connection = dependency;
}
/// <summary>
/// Resets this instance.
/// </summary>
internal void Reset()
{
m_Connection = null;
}
/// <summary>
/// Provides one of the services on which the current service depends.
/// </summary>
/// <param name="dependency">The dependency service.</param>
public override void ConnectTo(KernelService dependency)
{
m_Connection = dependency;
}
/// <summary>
/// Gets the services that depend on the specified service type.
/// </summary>
/// <param name="service">The service type.</param>
/// <returns>
/// A collection containing a mapping between the demanded dependency and the service that would
/// serve for this dependency.
/// </returns>
private IEnumerable <KeyValuePair <Type, KernelService> > GetDependentServices(KernelService service)
{
var result = new List <KeyValuePair <Type, KernelService> >();
foreach (var map in m_Services)
{
var dependencyHolder = map.Value as IHaveServiceDependencies;
if (dependencyHolder != null)
{
foreach (var dependency in dependencyHolder.ServicesToConnectTo())
{
if (dependency.IsAssignableFrom(service.GetType()))
{
result.Add(new KeyValuePair <Type, KernelService>(dependency, map.Value));
break;
}
}
}
}
return(result);
}
/// <summary>
/// Installs the specified service.
/// </summary>
/// <param name="service">The service which should be installed.</param>
/// <remarks>
/// <para>
/// Only services that are 'installed' can be used by the service manager.
/// Services that have not been installed are simply unknown to the service
/// manager.
/// </para>
/// <para>
/// Note that only one instance for each <c>Type</c> can be provided to
/// the service manager.
/// </para>
/// </remarks>
/// <exception cref="ArgumentNullException">
/// Thrown if <paramref name="service"/> is <see langword="null" />.
/// </exception>
public void Install(KernelService service)
{
{
Enforce.Argument(() => service);
}
if ((m_State != StartupState.NotStarted) && (m_State != StartupState.Started))
{
throw new KernelNotInInstallReadyStateException();
}
if (m_Services.ContainsKey(service.GetType()))
{
throw new ServiceTypeAlreadyInstalledException();
}
var dependencyHolder = service as IHaveServiceDependencies;
if (dependencyHolder != null)
{
if (dependencyHolder.ServicesToConnectTo().Contains(dependencyHolder.GetType()))
{
throw new ServiceCannotDependOnItselfException();
}
if (dependencyHolder.ServicesToConnectTo().Contains(typeof(KernelService)))
{
throw new ServiceCannotDependOnGenericKernelServiceException();
}
var selectedService = GetInstalledDependencies(dependencyHolder.ServicesToConnectTo());
foreach (var map in selectedService)
{
if (!m_Connections.ContainsKey(service))
{
m_Connections.Add(service, new List <ConnectionMap>());
}
var connection = m_Connections[service];
connection.Add(new ConnectionMap(map.Key, map.Value));
dependencyHolder.ConnectTo(map.Value);
}
}
var selectedServices = GetDependentServices(service);
foreach (var map in selectedServices)
{
if (!m_Connections.ContainsKey(map.Value))
{
m_Connections.Add(map.Value, new List <ConnectionMap>());
}
var connection = m_Connections[map.Value];
connection.Add(new ConnectionMap(map.Key, service));
var dependent = map.Value as IHaveServiceDependencies;
Debug.Assert(dependent != null, "The service should be able to handle dependencies.");
dependent.ConnectTo(service);
}
m_Services.Add(service.GetType(), service);
}
/// <summary>
/// Provides one of the services on which the current service depends.
/// </summary>
/// <param name="dependency">The dependency service.</param>
public virtual void ConnectTo(KernelService dependency)
{
// Do nothing here ...
}
/// <summary>
/// Gets the services that depend on the specified service type.
/// </summary>
/// <param name="service">The service type.</param>
/// <returns>
/// A collection containing a mapping between the demanded dependency and the service that would
/// serve for this dependency.
/// </returns>
private IEnumerable<KeyValuePair<Type, KernelService>> GetDependentServices(KernelService service)
{
var result = new List<KeyValuePair<Type, KernelService>>();
foreach (var map in m_Services)
{
var dependencyHolder = map.Value as IHaveServiceDependencies;
if (dependencyHolder != null)
{
foreach (var dependency in dependencyHolder.ServicesToConnectTo())
{
if (dependency.IsAssignableFrom(service.GetType()))
{
result.Add(new KeyValuePair<Type, KernelService>(dependency, map.Value));
break;
}
}
}
}
return result;
}
/// <summary>
/// Installs the specified service.
/// </summary>
/// <param name="service">The service which should be installed.</param>
/// <remarks>
/// <para>
/// Only services that are 'installed' can be used by the service manager.
/// Services that have not been installed are simply unknown to the service
/// manager.
/// </para>
/// <para>
/// Note that only one instance for each <c>Type</c> can be provided to
/// the service manager.
/// </para>
/// </remarks>
/// <exception cref="ArgumentNullException">
/// Thrown if <paramref name="service"/> is <see langword="null" />.
/// </exception>
public void Install(KernelService service)
{
{
Enforce.Argument(() => service);
}
if ((m_State != StartupState.NotStarted) && (m_State != StartupState.Started))
{
throw new KernelNotInInstallReadyStateException();
}
if (m_Services.ContainsKey(service.GetType()))
{
throw new ServiceTypeAlreadyInstalledException();
}
var dependencyHolder = service as IHaveServiceDependencies;
if (dependencyHolder != null)
{
if (dependencyHolder.ServicesToConnectTo().Contains(dependencyHolder.GetType()))
{
throw new ServiceCannotDependOnItselfException();
}
if (dependencyHolder.ServicesToConnectTo().Contains(typeof(KernelService)))
{
throw new ServiceCannotDependOnGenericKernelServiceException();
}
var selectedService = GetInstalledDependencies(dependencyHolder.ServicesToConnectTo());
foreach (var map in selectedService)
{
if (!m_Connections.ContainsKey(service))
{
m_Connections.Add(service, new List<ConnectionMap>());
}
var connection = m_Connections[service];
connection.Add(new ConnectionMap(map.Key, map.Value));
dependencyHolder.ConnectTo(map.Value);
}
}
var selectedServices = GetDependentServices(service);
foreach (var map in selectedServices)
{
if (!m_Connections.ContainsKey(map.Value))
{
m_Connections.Add(map.Value, new List<ConnectionMap>());
}
var connection = m_Connections[map.Value];
connection.Add(new ConnectionMap(map.Key, service));
var dependent = map.Value as IHaveServiceDependencies;
Debug.Assert(dependent != null, "The service should be able to handle dependencies.");
dependent.ConnectTo(service);
}
m_Services.Add(service.GetType(), service);
}
