use alloc::{boxed::Box, rc::Rc};
use core::{future::Future, pin::Pin};
use paste::paste;
use crate::{Service, ServiceFactory};
pub type BoxFuture<T> = Pin<Box<dyn Future<Output = T>>>;
macro_rules! service_object {
($name: ident, $type: tt, $fn_name: ident) => {
paste! {
#[doc = "Type alias for service trait object using `" $type "`."]
pub type $name<Req, Res, Err> = $type<
dyn Service<Req, Response = Res, Error = Err, Future = BoxFuture<Result<Res, Err>>>,
>;
#[doc = "Wraps service as a trait object using [`" $name "`]."]
pub fn $fn_name<S, Req>(service: S) -> $name<Req, S::Response, S::Error>
where
S: Service<Req> + 'static,
Req: 'static,
S::Future: 'static,
{
$type::new(ServiceWrapper::new(service))
}
}
};
}
service_object!(BoxService, Box, service);
service_object!(RcService, Rc, rc_service);
struct ServiceWrapper<S> {
inner: S,
}
impl<S> ServiceWrapper<S> {
fn new(inner: S) -> Self {
Self { inner }
}
}
impl<S, Req, Res, Err> Service<Req> for ServiceWrapper<S>
where
S: Service<Req, Response = Res, Error = Err>,
S::Future: 'static,
{
type Response = Res;
type Error = Err;
type Future = BoxFuture<Result<Res, Err>>;
crate::forward_ready!(inner);
fn call(&self, req: Req) -> Self::Future {
Box::pin(self.inner.call(req))
}
}
pub struct BoxServiceFactory<Cfg, Req, Res, Err, InitErr>(Inner<Cfg, Req, Res, Err, InitErr>);
pub fn factory<SF, Req>(
factory: SF,
) -> BoxServiceFactory<SF::Config, Req, SF::Response, SF::Error, SF::InitError>
where
SF: ServiceFactory<Req> + 'static,
Req: 'static,
SF::Response: 'static,
SF::Service: 'static,
SF::Future: 'static,
SF::Error: 'static,
SF::InitError: 'static,
{
BoxServiceFactory(Box::new(FactoryWrapper(factory)))
}
type Inner<C, Req, Res, Err, InitErr> = Box<
dyn ServiceFactory<
Req,
Config = C,
Response = Res,
Error = Err,
InitError = InitErr,
Service = BoxService<Req, Res, Err>,
Future = BoxFuture<Result<BoxService<Req, Res, Err>, InitErr>>,
>,
>;
impl<C, Req, Res, Err, InitErr> ServiceFactory<Req>
for BoxServiceFactory<C, Req, Res, Err, InitErr>
where
Req: 'static,
Res: 'static,
Err: 'static,
InitErr: 'static,
{
type Response = Res;
type Error = Err;
type Config = C;
type Service = BoxService<Req, Res, Err>;
type InitError = InitErr;
type Future = BoxFuture<Result<Self::Service, InitErr>>;
fn new_service(&self, cfg: C) -> Self::Future {
self.0.new_service(cfg)
}
}
struct FactoryWrapper<SF>(SF);
impl<SF, Req, Cfg, Res, Err, InitErr> ServiceFactory<Req> for FactoryWrapper<SF>
where
Req: 'static,
Res: 'static,
Err: 'static,
InitErr: 'static,
SF: ServiceFactory<Req, Config = Cfg, Response = Res, Error = Err, InitError = InitErr>,
SF::Future: 'static,
SF::Service: 'static,
<SF::Service as Service<Req>>::Future: 'static,
{
type Response = Res;
type Error = Err;
type Config = Cfg;
type Service = BoxService<Req, Res, Err>;
type InitError = InitErr;
type Future = BoxFuture<Result<Self::Service, Self::InitError>>;
fn new_service(&self, cfg: Cfg) -> Self::Future {
let f = self.0.new_service(cfg);
Box::pin(async { f.await.map(|s| Box::new(ServiceWrapper::new(s)) as _) })
}
}