/// <summary>
/// Loads the assembly from the byte array and executes the best matched method based on the incoming request.
/// </summary>
/// <param name="assemblyBytes">Byte array containing the assembly to be loaded.</param>
/// <param name="request"><see cref="RouteRequest"/> object containing all data for the current request.</param>
/// <returns><see cref="RouteResponse"/> object containing the response for the current request.</returns>
public RouteResponse Execute(byte[] assemblyBytes, RouteRequest request)
{
// Run the private async method synchronously.
var task = ExecuteAsync(assemblyBytes, request);
task.Wait();
return(task.Result);
}
public RouteResponse Execute(byte[] assemblyBytes, RouteRequest request)
{
var assembly = Assembly.Load(assemblyBytes);
var baseController = typeof(BaseController);
var classType = assembly.GetTypes().FirstOrDefault(t => t.InheritsFrom(baseController));
if (classType == null)
{
throw new EntryPointException($"Could not locate any types that inherit from '{baseController.Name}'.");
}
// Locate a public instance method that begins with the http method type.
var methodType = classType.GetMethods(BindingFlags.Instance | BindingFlags.Public)
.Where(m => !m.Name.Equals("GetHashCode") && !m.Name.Equals("GetType"))
.FirstOrDefault(m => m.Name.StartsWith(request.Method, StringComparison.CurrentCultureIgnoreCase));
if (methodType == null)
{
throw new EntryPointException($"No method was found for http verb '{request.Method}'.");
}
// Create an instance of controller.
var instance = classType.CreateInstance();
// Void methods are treated as a no content result, so we'll create the ExecutionResponse object ourselves with NoContent status code.
if (methodType.ReturnType == typeof(void))
{
return new RouteResponse(HttpStatusCode.NoContent)
{
Body = new byte[0]
}
}
;
// Methods that directly return an ExecutionResponse are considered bare-metal responses, so we'll just pass it along.
return((RouteResponse)methodType.Invoke(instance, new object[] { request }));
}
}
private async Task <RouteResponse> ExecuteAsync(byte[] assemblyBytes, RouteRequest request)
{
var assembly = Assembly.Load(assemblyBytes);
var baseController = typeof(BaseController);
var classType = assembly.GetTypes().FirstOrDefault(t => t.InheritsFrom(baseController));
if (classType == null)
{
throw new EntryPointException($"Could not locate any types that inherit from '{baseController.Name}'.");
}
// Locate a public instance method that begins with the http method type.
var methodType = classType.GetMethods(BindingFlags.Instance | BindingFlags.Public)
.Where(m => !m.Name.Equals("GetHashCode") && !m.Name.Equals("GetType"))
.FirstOrDefault(m => m.Name.StartsWith(request.Method, StringComparison.CurrentCultureIgnoreCase));
if (methodType == null)
{
throw new EntryPointException($"No method was found for http verb '{request.Method}'.");
}
// For async methods we need to ensure that the method is marked async. Otherwise we will fail
// with an exception. We could still run it, but we don't want to promote bad code.
if ((methodType.ReturnType == typeof(Task) || methodType.ReturnType.InheritsFrom(typeof(Task))) && !methodType.IsAsyncMethod())
{
throw new EntryPointException($"Found method named '{methodType.Name}' which returns Task, however the method must be marked as async.");
}
// Create an instance of controller and execute the method.
var instance = classType.CreateInstance();
var result = methodType.Invoke(instance, new object[] { request });
// Depending on the result, we can determine if a method is asynchronous or not
// and treat it as such by waiting for it to complete before returning the result.
switch (result)
{
// Standard synchronous return type, return it straight away.
case RouteResponse resultTyped:
return(resultTyped);
// Typed async result, wait for the result then return it.
case Task <RouteResponse> resultTaskTyped:
return(await resultTaskTyped);
// Untyped async result, wait for completion then return a no content result.
case Task resultTask:
await resultTask;
return(RouteResponse.NoContent);
// For void methods, we'll return a no content result, otherwise it's an unknown type so throw.
default:
// Void is a valid type, return an empty result.
if (methodType.ReturnType == typeof(void))
{
return(RouteResponse.NoContent);
}
// All other types should produce an exception because we aren't sure what they want us to do with it.
throw new EntryPointException($"Found method named '{methodType.Name}', but has an invalid return type. Valid types are void, RouteResponse, Task, and Task<RouteResponse>.");
}
}
