use std::{
convert::Infallible,
fmt,
marker::PhantomData,
task::{
Context,
Poll,
},
};
use futures::FutureExt;
use tower::Service;
use super::Handler;
use crate::{
make_service::IntoMakeService,
message::{
Message,
MessageHead,
},
response::Response,
};
pub struct HandlerService<H, T, S, R> {
handler: H,
state: S,
_marker: PhantomData<fn() -> T>,
_request_marker: PhantomData<R>,
}
impl<H, T, S, R> HandlerService<H, T, S, R> {
pub(super) fn new(handler: H, state: S) -> Self {
Self {
handler,
state,
_marker: PhantomData,
_request_marker: PhantomData,
}
}
pub fn into_make_service(self) -> IntoMakeService<HandlerService<H, T, S, R>> {
IntoMakeService::new(self)
}
pub fn state(&self) -> &S {
&self.state
}
}
impl<H, T, S, R> fmt::Debug for HandlerService<H, T, S, R> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.debug_struct("HandlerService").finish_non_exhaustive()
}
}
impl<H, T, S, R> Clone for HandlerService<H, T, S, R>
where
H: Clone,
S: Clone,
{
fn clone(&self) -> Self {
Self {
handler: self.handler.clone(),
state: self.state.clone(),
_marker: PhantomData,
_request_marker: PhantomData,
}
}
}
impl<H, T, S, R> Service<Message<R>> for HandlerService<H, T, S, R>
where
H: Handler<T, S, R> + Clone + Send + 'static,
S: Clone + Send + Sync,
R: MessageHead,
{
type Response = Response;
type Error = Infallible;
type Future = super::future::IntoServiceFuture<H::Future>;
fn poll_ready(&mut self, _cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
// `IntoService` can only be constructed from async functions which are always ready, or
// from `Layered` which buffers in `<Layered as Handler>::call` and is therefore
// also always ready.
Poll::Ready(Ok(()))
}
fn call(&mut self, req: Message<R>) -> Self::Future {
let handler = self.handler.clone();
let future = Handler::call(handler, req, self.state.clone());
let future = future.map(Ok as _);
super::future::IntoServiceFuture::new(future)
}
}