public IHandler GetHandler(Type service)
{
_handlersByService.TryGetValue(service, out var serviceHandler);
if (serviceHandler == null && service.GetTypeInfo().IsGenericType&& service.GetTypeInfo().IsGenericTypeDefinition == false)
{
var openService = service.GetGenericTypeDefinition();
var handlerCandidates = GetHandlers(openService);
foreach (var handlerCandidate in handlerCandidates)
{
if (handlerCandidate.Supports(service))
{
return(handlerCandidate);
}
}
}
var key = new ReplacementKey
{
Service = service,
Implementation = serviceHandler?.Handler.ComponentModel.Implementation
};
_replacementsByService.TryGetValue(key, out var replacement);
if (replacement?.IsActive ?? false)
{
return(replacement.Handler);
}
_togglableHandlersByService.TryGetValue(service, out var togglableHandlers);
// If replacement == null && togglableHandlers == null, this handler can be cached
return
(togglableHandlers?
.FirstOrDefault(togglableHandler => togglableHandler.IsActive)?.Handler
?? serviceHandler?.Handler);
}
private void RegisterReplacementByService(TogglableHandler togglableHandler)
{
foreach (var implementationType in togglableHandler.Replacement.Implementations)
{
foreach (var serviceType in togglableHandler.Replacement.Services)
{
var key = new ReplacementKey
{
Service = serviceType,
Implementation = implementationType
};
if (_replacementsByService.ContainsKey(key))
{
throw new InvalidOperationException(
$"Replacement of implementation '{implementationType.FullName}' " +
$"and service '{serviceType.FullName}' already registered");
}
_replacementsByService[key] = togglableHandler;
}
}
}
