internal static DirectiveDelegate CreateDelegate <TMiddleware>(
Func <IServiceProvider, FieldDelegate, TMiddleware> factory,
FieldDelegate next)
where TMiddleware : class
{
object sync = new object();
TMiddleware middleware = null;
ClassQueryDelegate <TMiddleware, IDirectiveContext> compiled =
MiddlewareCompiler <TMiddleware> .CompileDelegate <IDirectiveContext>(
(context, middleware) => new List <IParameterHandler>
{
new ServiceParameterHandler(Expression.Property(context, _services))
});
return(context =>
{
if (middleware is null)
{
lock (sync)
{
middleware = middleware ?? factory(context.Services, next);
}
}
return compiled(context, middleware);
});
}
internal static DirectiveMiddleware Create <TMiddleware>()
where TMiddleware : class
{
return(next =>
{
MiddlewareFactory <TMiddleware, IServiceProvider, FieldDelegate> factory =
MiddlewareCompiler <TMiddleware>
.CompileFactory <IServiceProvider, FieldDelegate>(
(services, next) =>
new IParameterHandler[] { new ServiceParameterHandler(services) });
return CreateDelegate(
(s, n) => factory(s, n),
next);
});
}
internal static RequestCoreMiddleware Create <TMiddleware>()
where TMiddleware : class
{
return((context, next) =>
{
TMiddleware middleware =
MiddlewareCompiler <TMiddleware>
.CompileFactory <IRequestCoreMiddlewareContext, RequestDelegate>(
(c, n) => CreateFactoryParameterHandlers(c, context.Options))
.Invoke(context, next);
ClassQueryDelegate <TMiddleware, IRequestContext> compiled =
MiddlewareCompiler <TMiddleware> .CompileDelegate <IRequestContext>(
(c, m) => CreateDelegateParameterHandlers(c, context.Options));
return c => compiled(c, middleware);
});
}
