src/routing.rs

use crate::{
    body::{Body, BoxBody},
    error::Error,
    handler::{Handler, HandlerSvc},
    App, IntoService,
};
use bytes::Bytes;
use futures_util::{future, ready};
use http::{Method, Request, Response, StatusCode};
use pin_project::pin_project;
use std::{
    convert::Infallible,
    fmt,
    future::Future,
    pin::Pin,
    task::{Context, Poll},
};
use tower::{
    buffer::{Buffer, BufferLayer},
    util::BoxService,
    BoxError, Service, ServiceBuilder,
};

#[derive(Clone, Copy)]
pub struct AlwaysNotFound(pub(crate) ());

impl<R> Service<R> for AlwaysNotFound {
    type Response = Response<Body>;
    type Error = Infallible;
    type Future = future::Ready<Result<Self::Response, Self::Error>>;

    fn poll_ready(&mut self, _cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
        Poll::Ready(Ok(()))
    }

    fn call(&mut self, _req: R) -> Self::Future {
        let mut res = Response::new(Body::empty());
        *res.status_mut() = StatusCode::NOT_FOUND;
        future::ok(res)
    }
}

#[derive(Debug, Clone)]
pub struct RouteAt<R> {
    pub(crate) app: App<R>,
    pub(crate) route_spec: Bytes,
}

impl<R> RouteAt<R> {
    pub fn get<F, B, T>(self, handler_fn: F) -> RouteBuilder<Or<HandlerSvc<F, B, T>, R>>
    where
        F: Handler<B, T>,
    {
        self.add_route(handler_fn, Method::GET)
    }

    pub fn get_service<S, B>(self, service: S) -> RouteBuilder<Or<S, R>>
    where
        S: Service<Request<Body>, Response = Response<B>> + Clone,
        S::Error: Into<BoxError>,
    {
        self.add_route_service(service, Method::GET)
    }

    pub fn post<F, B, T>(self, handler_fn: F) -> RouteBuilder<Or<HandlerSvc<F, B, T>, R>>
    where
        F: Handler<B, T>,
    {
        self.add_route(handler_fn, Method::POST)
    }

    pub fn post_service<S, B>(self, service: S) -> RouteBuilder<Or<S, R>>
    where
        S: Service<Request<Body>, Response = Response<B>> + Clone,
        S::Error: Into<BoxError>,
    {
        self.add_route_service(service, Method::POST)
    }

    fn add_route<H, B, T>(
        self,
        handler: H,
        method: Method,
    ) -> RouteBuilder<Or<HandlerSvc<H, B, T>, R>>
    where
        H: Handler<B, T>,
    {
        self.add_route_service(HandlerSvc::new(handler), method)
    }

    fn add_route_service<S>(self, service: S, method: Method) -> RouteBuilder<Or<S, R>> {
        assert!(
            self.route_spec.starts_with(b"/"),
            "route spec must start with a slash (`/`)"
        );

        let new_app = App {
            service_tree: Or {
                service,
                route_spec: RouteSpec::new(method, self.route_spec.clone()),
                fallback: self.app.service_tree,
                handler_ready: false,
                fallback_ready: false,
            },
        };

        RouteBuilder {
            app: new_app,
            route_spec: self.route_spec,
        }
    }
}

pub struct RouteBuilder<R> {
    app: App<R>,
    route_spec: Bytes,
}

impl<R> Clone for RouteBuilder<R>
where
    R: Clone,
{
    fn clone(&self) -> Self {
        Self {
            app: self.app.clone(),
            route_spec: self.route_spec.clone(),
        }
    }
}

impl<R> RouteBuilder<R> {
    pub fn at(self, route_spec: &str) -> RouteAt<R> {
        self.app.at(route_spec)
    }

    pub fn get<F, B, T>(self, handler_fn: F) -> RouteBuilder<Or<HandlerSvc<F, B, T>, R>>
    where
        F: Handler<B, T>,
    {
        self.app.at_bytes(self.route_spec).get(handler_fn)
    }

    pub fn get_service<S, B>(self, service: S) -> RouteBuilder<Or<S, R>>
    where
        S: Service<Request<Body>, Response = Response<B>> + Clone,
        S::Error: Into<BoxError>,
    {
        self.app.at_bytes(self.route_spec).get_service(service)
    }

    pub fn post<F, B, T>(self, handler_fn: F) -> RouteBuilder<Or<HandlerSvc<F, B, T>, R>>
    where
        F: Handler<B, T>,
    {
        self.app.at_bytes(self.route_spec).post(handler_fn)
    }

    pub fn post_service<S, B>(self, service: S) -> RouteBuilder<Or<S, R>>
    where
        S: Service<Request<Body>, Response = Response<B>> + Clone,
        S::Error: Into<BoxError>,
    {
        self.app.at_bytes(self.route_spec).post_service(service)
    }

    pub fn into_service(self) -> IntoService<R> {
        IntoService {
            app: self.app,
            poll_ready_error: None,
        }
    }

    pub fn boxed<B>(self) -> RouteBuilder<BoxServiceTree<B>>
    where
        R: Service<Request<Body>, Response = Response<B>, Error = Error> + Send + 'static,
        R::Future: Send,
        B: Default + 'static,
    {
        let svc = ServiceBuilder::new()
            .layer(BufferLayer::new(1024))
            .layer(BoxService::layer())
            .service(self.app.service_tree);

        let app = App {
            service_tree: BoxServiceTree { inner: svc },
        };

        RouteBuilder {
            app,
            route_spec: self.route_spec,
        }
    }
}

pub struct Or<H, F> {
    service: H,
    route_spec: RouteSpec,
    fallback: F,
    handler_ready: bool,
    fallback_ready: bool,
}

impl<H, F> Clone for Or<H, F>
where
    H: Clone,
    F: Clone,
{
    fn clone(&self) -> Self {
        Self {
            service: self.service.clone(),
            fallback: self.fallback.clone(),
            route_spec: self.route_spec.clone(),
            // important to reset readiness when cloning
            handler_ready: false,
            fallback_ready: false,
        }
    }
}

#[derive(Clone)]
struct RouteSpec {
    method: Method,
    spec: Bytes,
}

impl RouteSpec {
    fn new(method: Method, spec: impl Into<Bytes>) -> Self {
        Self {
            method,
            spec: spec.into(),
        }
    }
}

impl RouteSpec {
    fn matches<B>(&self, req: &Request<B>) -> Option<Vec<(String, String)>> {
        if req.method() != self.method {
            return None;
        }

        let path = req.uri().path().as_bytes();
        let path_parts = path.split(|b| *b == b'/');

        let spec_parts = self.spec.split(|b| *b == b'/');

        if spec_parts.clone().count() != path_parts.clone().count() {
            return None;
        }

        let mut params = Vec::new();

        spec_parts
            .zip(path_parts)
            .all(|(spec, path)| {
                if let Some(key) = spec.strip_prefix(b":") {
                    let key = std::str::from_utf8(key).unwrap().to_string();
                    if let Ok(value) = std::str::from_utf8(path) {
                        params.push((key, value.to_string()));
                        true
                    } else {
                        false
                    }
                } else {
                    spec == path
                }
            })
            .then(|| params)
    }
}

impl<H, F, HB, FB> Service<Request<Body>> for Or<H, F>
where
    H: Service<Request<Body>, Response = Response<HB>>,
    H::Error: Into<Error>,
    HB: http_body::Body + Send + Sync + 'static,
    HB::Error: Into<BoxError>,

    F: Service<Request<Body>, Response = Response<FB>>,
    F::Error: Into<Error>,
    FB: http_body::Body<Data = HB::Data> + Send + Sync + 'static,
    FB::Error: Into<BoxError>,
{
    type Response = Response<BoxBody<HB::Data, Error>>;
    type Error = Error;
    type Future = future::Either<BoxResponseBody<H::Future>, BoxResponseBody<F::Future>>;

    fn poll_ready(&mut self, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
        loop {
            if !self.handler_ready {
                ready!(self.service.poll_ready(cx)).map_err(Into::into)?;
                self.handler_ready = true;
            }

            if !self.fallback_ready {
                ready!(self.fallback.poll_ready(cx)).map_err(Into::into)?;
                self.fallback_ready = true;
            }

            if self.handler_ready && self.fallback_ready {
                return Poll::Ready(Ok(()));
            }
        }
    }

    fn call(&mut self, mut req: Request<Body>) -> Self::Future {
        if let Some(params) = self.route_spec.matches(&req) {
            assert!(
                self.handler_ready,
                "handler not ready. Did you forget to call `poll_ready`?"
            );

            self.handler_ready = false;

            req.extensions_mut().insert(Some(UrlParams(params)));

            future::Either::Left(BoxResponseBody(self.service.call(req)))
        } else {
            assert!(
                self.fallback_ready,
                "fallback not ready. Did you forget to call `poll_ready`?"
            );

            self.fallback_ready = false;

            // TODO(david): this leads to each route creating one box body, probably not great
            future::Either::Right(BoxResponseBody(self.fallback.call(req)))
        }
    }
}

pub(crate) struct UrlParams(pub(crate) Vec<(String, String)>);

#[pin_project]
pub struct BoxResponseBody<F>(#[pin] F);

impl<F, B, E> Future for BoxResponseBody<F>
where
    F: Future<Output = Result<Response<B>, E>>,
    E: Into<Error>,
    B: http_body::Body + Send + Sync + 'static,
    B::Error: Into<BoxError>,
{
    type Output = Result<Response<BoxBody<B::Data, Error>>, Error>;

    fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
        let response: Response<B> = ready!(self.project().0.poll(cx)).map_err(Into::into)?;
        let response = response.map(|body| {
            // TODO(david): attempt to downcast this into `Error`
            let body = body.map_err(|err| Error::ResponseBody(err.into()));
            BoxBody::new(body)
        });
        Poll::Ready(Ok(response))
    }
}

pub struct BoxServiceTree<B> {
    inner: Buffer<BoxService<Request<Body>, Response<B>, Error>, Request<Body>>,
}

impl<B> Clone for BoxServiceTree<B> {
    fn clone(&self) -> Self {
        Self {
            inner: self.inner.clone(),
        }
    }
}

impl<B> fmt::Debug for BoxServiceTree<B> {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        f.debug_struct("BoxServiceTree").finish()
    }
}

impl<B> Service<Request<Body>> for BoxServiceTree<B>
where
    B: 'static,
{
    type Response = Response<B>;
    type Error = Error;
    type Future = BoxServiceTreeResponseFuture<B>;

    #[inline]
    fn poll_ready(&mut self, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
        self.inner.poll_ready(cx).map_err(Error::from_service_error)
    }

    #[inline]
    fn call(&mut self, req: Request<Body>) -> Self::Future {
        BoxServiceTreeResponseFuture {
            inner: self.inner.call(req),
        }
    }
}

#[pin_project]
pub struct BoxServiceTreeResponseFuture<B> {
    #[pin]
    inner: InnerFuture<B>,
}

type InnerFuture<B> = tower::buffer::future::ResponseFuture<
    Pin<Box<dyn Future<Output = Result<Response<B>, Error>> + Send + 'static>>,
>;

impl<B> Future for BoxServiceTreeResponseFuture<B> {
    type Output = Result<Response<B>, Error>;

    fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
        self.project()
            .inner
            .poll(cx)
            .map_err(Error::from_service_error)
    }
}

#[cfg(test)]
mod tests {
    #[allow(unused_imports)]
    use super::*;

    #[test]
    fn test_routing() {
        assert_match((Method::GET, "/"), (Method::GET, "/"));
        refute_match((Method::GET, "/"), (Method::POST, "/"));
        refute_match((Method::POST, "/"), (Method::GET, "/"));

        assert_match((Method::GET, "/foo"), (Method::GET, "/foo"));
        assert_match((Method::GET, "/foo/"), (Method::GET, "/foo/"));
        refute_match((Method::GET, "/foo"), (Method::GET, "/foo/"));
        refute_match((Method::GET, "/foo/"), (Method::GET, "/foo"));

        assert_match((Method::GET, "/foo/bar"), (Method::GET, "/foo/bar"));
        refute_match((Method::GET, "/foo/bar/"), (Method::GET, "/foo/bar"));
        refute_match((Method::GET, "/foo/bar"), (Method::GET, "/foo/bar/"));

        assert_match((Method::GET, "/:value"), (Method::GET, "/foo"));
        assert_match((Method::GET, "/users/:id"), (Method::GET, "/users/1"));
        assert_match(
            (Method::GET, "/users/:id/action"),
            (Method::GET, "/users/42/action"),
        );
        refute_match(
            (Method::GET, "/users/:id/action"),
            (Method::GET, "/users/42"),
        );
        refute_match(
            (Method::GET, "/users/:id"),
            (Method::GET, "/users/42/action"),
        );
    }

    fn assert_match(route_spec: (Method, &'static str), req_spec: (Method, &'static str)) {
        let route = RouteSpec::new(route_spec.0.clone(), route_spec.1);
        let req = Request::builder()
            .method(req_spec.0.clone())
            .uri(req_spec.1)
            .body(())
            .unwrap();

        assert!(
            route.matches(&req).is_some(),
            "`{} {}` doesn't match `{} {}`",
            req.method(),
            req.uri().path(),
            route.method,
            std::str::from_utf8(&route.spec).unwrap(),
        );
    }

    fn refute_match(route_spec: (Method, &'static str), req_spec: (Method, &'static str)) {
        let route = RouteSpec::new(route_spec.0.clone(), route_spec.1);
        let req = Request::builder()
            .method(req_spec.0.clone())
            .uri(req_spec.1)
            .body(())
            .unwrap();

        assert!(
            route.matches(&req).is_none(),
            "`{} {}` shouldn't match `{} {}`",
            req.method(),
            req.uri().path(),
            route.method,
            std::str::from_utf8(&route.spec).unwrap(),
        );
    }
}
Break things into modules 2021-05-30 13:24:03 +02:00			`use crate::{`
			`body::{Body, BoxBody},`
			`error::Error,`
			`handler::{Handler, HandlerSvc},`
			`App, IntoService,`
			`};`
			`use bytes::Bytes;`
			`use futures_util::{future, ready};`
			`use http::{Method, Request, Response, StatusCode};`
			`use pin_project::pin_project;`
			`use std::{`
			`convert::Infallible,`
More work 2021-05-31 16:28:26 +02:00			`fmt,`
Break things into modules 2021-05-30 13:24:03 +02:00			`future::Future,`
			`pin::Pin,`
			`task::{Context, Poll},`
			`};`
More work 2021-05-31 16:28:26 +02:00			`use tower::{`
			`buffer::{Buffer, BufferLayer},`
			`util::BoxService,`
			`BoxError, Service, ServiceBuilder,`
			`};`
Break things into modules 2021-05-30 13:24:03 +02:00
			`#[derive(Clone, Copy)]`
More work 2021-05-31 16:28:26 +02:00			`pub struct AlwaysNotFound(pub(crate) ());`
Break things into modules 2021-05-30 13:24:03 +02:00
More work 2021-05-31 16:28:26 +02:00			`impl<R> Service<R> for AlwaysNotFound {`
Break things into modules 2021-05-30 13:24:03 +02:00			`type Response = Response<Body>;`
			`type Error = Infallible;`
			`type Future = future::Ready<Result<Self::Response, Self::Error>>;`

			`fn poll_ready(&mut self, _cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {`
			`Poll::Ready(Ok(()))`
			`}`

			`fn call(&mut self, _req: R) -> Self::Future {`
			`let mut res = Response::new(Body::empty());`
			`*res.status_mut() = StatusCode::NOT_FOUND;`
			`future::ok(res)`
			`}`
			`}`

			`#[derive(Debug, Clone)]`
			`pub struct RouteAt<R> {`
			`pub(crate) app: App<R>,`
			`pub(crate) route_spec: Bytes,`
			`}`

			`impl<R> RouteAt<R> {`
More work 2021-05-31 16:28:26 +02:00			`pub fn get<F, B, T>(self, handler_fn: F) -> RouteBuilder<Or<HandlerSvc<F, B, T>, R>>`
Break things into modules 2021-05-30 13:24:03 +02:00			`where`
			`F: Handler<B, T>,`
			`{`
			`self.add_route(handler_fn, Method::GET)`
			`}`

More work 2021-05-31 16:28:26 +02:00			`pub fn get_service<S, B>(self, service: S) -> RouteBuilder<Or<S, R>>`
Break things into modules 2021-05-30 13:24:03 +02:00			`where`
			`S: Service<Request<Body>, Response = Response<B>> + Clone,`
			`S::Error: Into<BoxError>,`
			`{`
			`self.add_route_service(service, Method::GET)`
			`}`

More work 2021-05-31 16:28:26 +02:00			`pub fn post<F, B, T>(self, handler_fn: F) -> RouteBuilder<Or<HandlerSvc<F, B, T>, R>>`
Break things into modules 2021-05-30 13:24:03 +02:00			`where`
			`F: Handler<B, T>,`
			`{`
			`self.add_route(handler_fn, Method::POST)`
			`}`

More work 2021-05-31 16:28:26 +02:00			`pub fn post_service<S, B>(self, service: S) -> RouteBuilder<Or<S, R>>`
Break things into modules 2021-05-30 13:24:03 +02:00			`where`
			`S: Service<Request<Body>, Response = Response<B>> + Clone,`
			`S::Error: Into<BoxError>,`
			`{`
			`self.add_route_service(service, Method::POST)`
			`}`

			`fn add_route<H, B, T>(`
			`self,`
			`handler: H,`
			`method: Method,`
More work 2021-05-31 16:28:26 +02:00			`) -> RouteBuilder<Or<HandlerSvc<H, B, T>, R>>`
Break things into modules 2021-05-30 13:24:03 +02:00			`where`
			`H: Handler<B, T>,`
			`{`
			`self.add_route_service(HandlerSvc::new(handler), method)`
			`}`

More work 2021-05-31 16:28:26 +02:00			`fn add_route_service<S>(self, service: S, method: Method) -> RouteBuilder<Or<S, R>> {`
Routing with dynamic parts! 2021-05-30 15:44:26 +02:00			`assert!(`
			`self.route_spec.starts_with(b"/"),`
			"route spec must start with a slash (`/`)"
			`);`

Break things into modules 2021-05-30 13:24:03 +02:00			`let new_app = App {`
More work 2021-05-31 16:28:26 +02:00			`service_tree: Or {`
Break things into modules 2021-05-30 13:24:03 +02:00			`service,`
Routing with dynamic parts! 2021-05-30 15:44:26 +02:00			`route_spec: RouteSpec::new(method, self.route_spec.clone()),`
More work 2021-05-31 16:28:26 +02:00			`fallback: self.app.service_tree,`
Break things into modules 2021-05-30 13:24:03 +02:00			`handler_ready: false,`
			`fallback_ready: false,`
			`},`
			`};`

			`RouteBuilder {`
			`app: new_app,`
			`route_spec: self.route_spec,`
			`}`
			`}`
			`}`

			`pub struct RouteBuilder<R> {`
			`app: App<R>,`
			`route_spec: Bytes,`
			`}`

			`impl<R> Clone for RouteBuilder<R>`
			`where`
			`R: Clone,`
			`{`
			`fn clone(&self) -> Self {`
			`Self {`
			`app: self.app.clone(),`
			`route_spec: self.route_spec.clone(),`
			`}`
			`}`
			`}`

			`impl<R> RouteBuilder<R> {`
			`pub fn at(self, route_spec: &str) -> RouteAt<R> {`
			`self.app.at(route_spec)`
			`}`

More work 2021-05-31 16:28:26 +02:00			`pub fn get<F, B, T>(self, handler_fn: F) -> RouteBuilder<Or<HandlerSvc<F, B, T>, R>>`
Break things into modules 2021-05-30 13:24:03 +02:00			`where`
			`F: Handler<B, T>,`
			`{`
			`self.app.at_bytes(self.route_spec).get(handler_fn)`
			`}`

More work 2021-05-31 16:28:26 +02:00			`pub fn get_service<S, B>(self, service: S) -> RouteBuilder<Or<S, R>>`
Break things into modules 2021-05-30 13:24:03 +02:00			`where`
			`S: Service<Request<Body>, Response = Response<B>> + Clone,`
			`S::Error: Into<BoxError>,`
			`{`
			`self.app.at_bytes(self.route_spec).get_service(service)`
			`}`

More work 2021-05-31 16:28:26 +02:00			`pub fn post<F, B, T>(self, handler_fn: F) -> RouteBuilder<Or<HandlerSvc<F, B, T>, R>>`
Break things into modules 2021-05-30 13:24:03 +02:00			`where`
			`F: Handler<B, T>,`
			`{`
			`self.app.at_bytes(self.route_spec).post(handler_fn)`
			`}`

More work 2021-05-31 16:28:26 +02:00			`pub fn post_service<S, B>(self, service: S) -> RouteBuilder<Or<S, R>>`
Break things into modules 2021-05-30 13:24:03 +02:00			`where`
			`S: Service<Request<Body>, Response = Response<B>> + Clone,`
			`S::Error: Into<BoxError>,`
			`{`
			`self.app.at_bytes(self.route_spec).post_service(service)`
			`}`

			`pub fn into_service(self) -> IntoService<R> {`
			`IntoService {`
			`app: self.app,`
			`poll_ready_error: None,`
			`}`
			`}`
More work 2021-05-31 16:28:26 +02:00
			`pub fn boxed<B>(self) -> RouteBuilder<BoxServiceTree<B>>`
			`where`
			`R: Service<Request<Body>, Response = Response<B>, Error = Error> + Send + 'static,`
			`R::Future: Send,`
			`B: Default + 'static,`
			`{`
			`let svc = ServiceBuilder::new()`
			`.layer(BufferLayer::new(1024))`
			`.layer(BoxService::layer())`
			`.service(self.app.service_tree);`

			`let app = App {`
			`service_tree: BoxServiceTree { inner: svc },`
			`};`

			`RouteBuilder {`
			`app,`
			`route_spec: self.route_spec,`
			`}`
			`}`
Break things into modules 2021-05-30 13:24:03 +02:00			`}`

More work 2021-05-31 16:28:26 +02:00			`pub struct Or<H, F> {`
Break things into modules 2021-05-30 13:24:03 +02:00			`service: H,`
			`route_spec: RouteSpec,`
			`fallback: F,`
			`handler_ready: bool,`
			`fallback_ready: bool,`
			`}`

More work 2021-05-31 16:28:26 +02:00			`impl<H, F> Clone for Or<H, F>`
Break things into modules 2021-05-30 13:24:03 +02:00			`where`
			`H: Clone,`
			`F: Clone,`
			`{`
			`fn clone(&self) -> Self {`
			`Self {`
			`service: self.service.clone(),`
			`fallback: self.fallback.clone(),`
			`route_spec: self.route_spec.clone(),`
			`// important to reset readiness when cloning`
			`handler_ready: false,`
			`fallback_ready: false,`
			`}`
			`}`
			`}`

			`#[derive(Clone)]`
			`struct RouteSpec {`
			`method: Method,`
			`spec: Bytes,`
			`}`

			`impl RouteSpec {`
Routing with dynamic parts! 2021-05-30 15:44:26 +02:00			`fn new(method: Method, spec: impl Into<Bytes>) -> Self {`
			`Self {`
			`method,`
			`spec: spec.into(),`
			`}`
			`}`
			`}`

			`impl RouteSpec {`
			`fn matches<B>(&self, req: &Request<B>) -> Option<Vec<(String, String)>> {`
			`if req.method() != self.method {`
			`return None;`
			`}`

			`let path = req.uri().path().as_bytes();`
			`let path_parts = path.split(\|b\| *b == b'/');`

			`let spec_parts = self.spec.split(\|b\| *b == b'/');`

			`if spec_parts.clone().count() != path_parts.clone().count() {`
			`return None;`
			`}`

			`let mut params = Vec::new();`

			`spec_parts`
			`.zip(path_parts)`
			`.all(\|(spec, path)\| {`
			`if let Some(key) = spec.strip_prefix(b":") {`
			`let key = std::str::from_utf8(key).unwrap().to_string();`
			`if let Ok(value) = std::str::from_utf8(path) {`
			`params.push((key, value.to_string()));`
			`true`
			`} else {`
			`false`
			`}`
			`} else {`
			`spec == path`
			`}`
			`})`
			`.then(\|\| params)`
Break things into modules 2021-05-30 13:24:03 +02:00			`}`
			`}`

More work 2021-05-31 16:28:26 +02:00			`impl<H, F, HB, FB> Service<Request<Body>> for Or<H, F>`
Break things into modules 2021-05-30 13:24:03 +02:00			`where`
			`H: Service<Request<Body>, Response = Response<HB>>,`
			`H::Error: Into<Error>,`
			`HB: http_body::Body + Send + Sync + 'static,`
			`HB::Error: Into<BoxError>,`

			`F: Service<Request<Body>, Response = Response<FB>>,`
			`F::Error: Into<Error>,`
			`FB: http_body::Body<Data = HB::Data> + Send + Sync + 'static,`
			`FB::Error: Into<BoxError>,`
			`{`
			`type Response = Response<BoxBody<HB::Data, Error>>;`
			`type Error = Error;`
			`type Future = future::Either<BoxResponseBody<H::Future>, BoxResponseBody<F::Future>>;`

			`fn poll_ready(&mut self, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {`
			`loop {`
			`if !self.handler_ready {`
			`ready!(self.service.poll_ready(cx)).map_err(Into::into)?;`
			`self.handler_ready = true;`
			`}`

			`if !self.fallback_ready {`
			`ready!(self.fallback.poll_ready(cx)).map_err(Into::into)?;`
			`self.fallback_ready = true;`
			`}`

			`if self.handler_ready && self.fallback_ready {`
			`return Poll::Ready(Ok(()));`
			`}`
			`}`
			`}`

Routing with dynamic parts! 2021-05-30 15:44:26 +02:00			`fn call(&mut self, mut req: Request<Body>) -> Self::Future {`
			`if let Some(params) = self.route_spec.matches(&req) {`
Break things into modules 2021-05-30 13:24:03 +02:00			`assert!(`
			`self.handler_ready,`
			"handler not ready. Did you forget to call `poll_ready`?"
			`);`

			`self.handler_ready = false;`

Routing with dynamic parts! 2021-05-30 15:44:26 +02:00			`req.extensions_mut().insert(Some(UrlParams(params)));`

Break things into modules 2021-05-30 13:24:03 +02:00			`future::Either::Left(BoxResponseBody(self.service.call(req)))`
			`} else {`
			`assert!(`
			`self.fallback_ready,`
			"fallback not ready. Did you forget to call `poll_ready`?"
			`);`

			`self.fallback_ready = false;`

			`// TODO(david): this leads to each route creating one box body, probably not great`
			`future::Either::Right(BoxResponseBody(self.fallback.call(req)))`
			`}`
			`}`
			`}`

Routing with dynamic parts! 2021-05-30 15:44:26 +02:00			`pub(crate) struct UrlParams(pub(crate) Vec<(String, String)>);`

Break things into modules 2021-05-30 13:24:03 +02:00			`#[pin_project]`
			`pub struct BoxResponseBody<F>(#[pin] F);`

			`impl<F, B, E> Future for BoxResponseBody<F>`
			`where`
			`F: Future<Output = Result<Response<B>, E>>,`
			`E: Into<Error>,`
			`B: http_body::Body + Send + Sync + 'static,`
			`B::Error: Into<BoxError>,`
			`{`
			`type Output = Result<Response<BoxBody<B::Data, Error>>, Error>;`

			`fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {`
			`let response: Response<B> = ready!(self.project().0.poll(cx)).map_err(Into::into)?;`
			`let response = response.map(\|body\| {`
			// TODO(david): attempt to downcast this into `Error`
			`let body = body.map_err(\|err\| Error::ResponseBody(err.into()));`
			`BoxBody::new(body)`
			`});`
			`Poll::Ready(Ok(response))`
			`}`
			`}`
Routing with dynamic parts! 2021-05-30 15:44:26 +02:00
More work 2021-05-31 16:28:26 +02:00			`pub struct BoxServiceTree<B> {`
			`inner: Buffer<BoxService<Request<Body>, Response<B>, Error>, Request<Body>>,`
			`}`

			`impl<B> Clone for BoxServiceTree<B> {`
			`fn clone(&self) -> Self {`
			`Self {`
			`inner: self.inner.clone(),`
			`}`
			`}`
			`}`

			`impl<B> fmt::Debug for BoxServiceTree<B> {`
			`fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {`
			`f.debug_struct("BoxServiceTree").finish()`
			`}`
			`}`

			`impl<B> Service<Request<Body>> for BoxServiceTree<B>`
			`where`
			`B: 'static,`
			`{`
			`type Response = Response<B>;`
			`type Error = Error;`
			`type Future = BoxServiceTreeResponseFuture<B>;`

			`#[inline]`
			`fn poll_ready(&mut self, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {`
			`self.inner.poll_ready(cx).map_err(Error::from_service_error)`
			`}`

			`#[inline]`
			`fn call(&mut self, req: Request<Body>) -> Self::Future {`
			`BoxServiceTreeResponseFuture {`
			`inner: self.inner.call(req),`
			`}`
			`}`
			`}`

			`#[pin_project]`
			`pub struct BoxServiceTreeResponseFuture<B> {`
			`#[pin]`
			`inner: InnerFuture<B>,`
			`}`

			`type InnerFuture<B> = tower::buffer::future::ResponseFuture<`
			`Pin<Box<dyn Future<Output = Result<Response<B>, Error>> + Send + 'static>>,`
			`>;`

			`impl<B> Future for BoxServiceTreeResponseFuture<B> {`
			`type Output = Result<Response<B>, Error>;`

			`fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {`
			`self.project()`
			`.inner`
			`.poll(cx)`
			`.map_err(Error::from_service_error)`
			`}`
			`}`

Routing with dynamic parts! 2021-05-30 15:44:26 +02:00			`#[cfg(test)]`
			`mod tests {`
			`#[allow(unused_imports)]`
			`use super::*;`

			`#[test]`
			`fn test_routing() {`
			`assert_match((Method::GET, "/"), (Method::GET, "/"));`
			`refute_match((Method::GET, "/"), (Method::POST, "/"));`
			`refute_match((Method::POST, "/"), (Method::GET, "/"));`

			`assert_match((Method::GET, "/foo"), (Method::GET, "/foo"));`
			`assert_match((Method::GET, "/foo/"), (Method::GET, "/foo/"));`
			`refute_match((Method::GET, "/foo"), (Method::GET, "/foo/"));`
			`refute_match((Method::GET, "/foo/"), (Method::GET, "/foo"));`

			`assert_match((Method::GET, "/foo/bar"), (Method::GET, "/foo/bar"));`
			`refute_match((Method::GET, "/foo/bar/"), (Method::GET, "/foo/bar"));`
			`refute_match((Method::GET, "/foo/bar"), (Method::GET, "/foo/bar/"));`

			`assert_match((Method::GET, "/:value"), (Method::GET, "/foo"));`
			`assert_match((Method::GET, "/users/:id"), (Method::GET, "/users/1"));`
			`assert_match(`
			`(Method::GET, "/users/:id/action"),`
			`(Method::GET, "/users/42/action"),`
			`);`
			`refute_match(`
			`(Method::GET, "/users/:id/action"),`
			`(Method::GET, "/users/42"),`
			`);`
			`refute_match(`
			`(Method::GET, "/users/:id"),`
			`(Method::GET, "/users/42/action"),`
			`);`
			`}`

			`fn assert_match(route_spec: (Method, &'static str), req_spec: (Method, &'static str)) {`
			`let route = RouteSpec::new(route_spec.0.clone(), route_spec.1);`
			`let req = Request::builder()`
			`.method(req_spec.0.clone())`
			`.uri(req_spec.1)`
			`.body(())`
			`.unwrap();`

			`assert!(`
			`route.matches(&req).is_some(),`
			"`{} {}` doesn't match `{} {}`",
			`req.method(),`
			`req.uri().path(),`
			`route.method,`
			`std::str::from_utf8(&route.spec).unwrap(),`
			`);`
			`}`

			`fn refute_match(route_spec: (Method, &'static str), req_spec: (Method, &'static str)) {`
			`let route = RouteSpec::new(route_spec.0.clone(), route_spec.1);`
			`let req = Request::builder()`
			`.method(req_spec.0.clone())`
			`.uri(req_spec.1)`
			`.body(())`
			`.unwrap();`

			`assert!(`
			`route.matches(&req).is_none(),`
			"`{} {}` shouldn't match `{} {}`",
			`req.method(),`
			`req.uri().path(),`
			`route.method,`
			`std::str::from_utf8(&route.spec).unwrap(),`
			`);`
			`}`
			`}`