internal static QueryDelegate CreateDelegate <TMiddleware>(
Func <IServiceProvider, QueryDelegate, TMiddleware> factory,
QueryDelegate next)
where TMiddleware : class
{
object sync = new object();
TMiddleware middleware = null;
var compiled = MiddlewareActivator
.CompileMiddleware <TMiddleware, IQueryContext>();
return(context =>
{
if (middleware == null)
{
lock (sync)
{
if (middleware == null)
{
middleware = factory(context.Services, next);
}
}
}
return compiled(context, context.Services, middleware);
});
}
private static FieldDelegate CreateDelegate <TMiddleware>(
Func <IServiceProvider, FieldDelegate, TMiddleware> factory,
FieldDelegate next)
where TMiddleware : class
{
object sync = new object();
TMiddleware middleware = null;
ClassQueryDelegate <TMiddleware, IMiddlewareContext> compiled =
MiddlewareActivator
.CompileMiddleware <TMiddleware, IMiddlewareContext>();
return(context =>
{
if (middleware == null)
{
lock (sync)
{
if (middleware == null)
{
middleware = factory(
context.Service <IServiceProvider>(),
next);
}
}
}
return compiled(
context,
context.Service <IServiceProvider>(),
middleware);
});
}