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use super::{Frame, RequestId, Transport};
use super::advanced::{Multiplex, MultiplexMessage};
use BindServer;
use streaming::{Message, Body};
use tokio_service::Service;
use tokio_core::reactor::Handle;
use futures::{Future, Poll, Async};
use futures::{IntoFuture, Stream};
use std::io;
pub trait ServerProto<T: 'static>: 'static {
type Request: 'static;
type RequestBody: 'static;
type Response: 'static;
type ResponseBody: 'static;
type Error: From<io::Error> + 'static;
type Transport:
Transport<Self::RequestBody,
Item = Frame<Self::Request, Self::RequestBody, Self::Error>,
SinkItem = Frame<Self::Response, Self::ResponseBody, Self::Error>>;
type BindTransport: IntoFuture<Item = Self::Transport, Error = io::Error>;
fn bind_transport(&self, io: T) -> Self::BindTransport;
}
impl<P, T, B> BindServer<super::StreamingMultiplex<B>, T> for P where
P: ServerProto<T>,
T: 'static,
B: Stream<Item = P::ResponseBody, Error = P::Error>,
{
type ServiceRequest = Message<P::Request, Body<P::RequestBody, P::Error>>;
type ServiceResponse = Message<P::Response, B>;
type ServiceError = P::Error;
fn bind_server<S>(&self, handle: &Handle, io: T, service: S)
where S: Service<Request = Self::ServiceRequest,
Response = Self::ServiceResponse,
Error = Self::ServiceError> + 'static
{
let task = self.bind_transport(io).into_future().and_then(|transport| {
let dispatch: Dispatch<S, T, P> = Dispatch {
service: service,
transport: transport,
in_flight: vec![],
};
Multiplex::new(dispatch)
}).map_err(|_| ());
handle.spawn(task)
}
}
struct Dispatch<S, T, P> where
T: 'static, P: ServerProto<T>, S: Service
{
service: S,
transport: P::Transport,
in_flight: Vec<(RequestId, InFlight<S::Future>)>,
}
enum InFlight<F: Future> {
Active(F),
Done(Result<F::Item, F::Error>),
}
const MAX_IN_FLIGHT_REQUESTS: usize = 32;
impl<P, T, B, S> super::advanced::Dispatch for Dispatch<S, T, P> where
P: ServerProto<T>,
B: Stream<Item = P::ResponseBody, Error = P::Error>,
S: Service<Request = Message<P::Request, Body<P::RequestBody, P::Error>>,
Response = Message<P::Response, B>,
Error = P::Error>,
{
type Io = T;
type In = P::Response;
type BodyIn = P::ResponseBody;
type Out = P::Request;
type BodyOut = P::RequestBody;
type Error = P::Error;
type Stream = B;
type Transport = P::Transport;
fn transport(&mut self) -> &mut P::Transport {
&mut self.transport
}
fn poll(&mut self) -> Poll<Option<MultiplexMessage<Self::In, B, Self::Error>>, io::Error> {
trace!("Dispatch::poll");
let mut idx = None;
for (i, &mut (request_id, ref mut slot)) in self.in_flight.iter_mut().enumerate() {
trace!(" --> poll; request_id={:?}", request_id);
if slot.poll() && idx.is_none() {
idx = Some(i);
}
}
if let Some(idx) = idx {
let (request_id, message) = self.in_flight.remove(idx);
let message = MultiplexMessage {
id: request_id,
message: message.unwrap_done(),
solo: false,
};
Ok(Async::Ready(Some(message)))
} else {
Ok(Async::NotReady)
}
}
fn dispatch(&mut self, message: MultiplexMessage<Self::Out, Body<Self::BodyOut, Self::Error>, Self::Error>) -> io::Result<()> {
assert!(self.poll_ready().is_ready());
let MultiplexMessage { id, message, solo } = message;
assert!(!solo);
if let Ok(request) = message {
let response = self.service.call(request);
self.in_flight.push((id, InFlight::Active(response)));
}
Ok(())
}
fn poll_ready(&self) -> Async<()> {
if self.in_flight.len() < MAX_IN_FLIGHT_REQUESTS {
Async::Ready(())
} else {
Async::NotReady
}
}
fn cancel(&mut self, _request_id: RequestId) -> io::Result<()> {
Ok(())
}
}
impl<F> InFlight<F>
where F: Future,
{
fn poll(&mut self) -> bool {
let res = match *self {
InFlight::Active(ref mut f) => {
trace!(" --> polling future");
match f.poll() {
Ok(Async::Ready(e)) => Ok(e),
Err(e) => Err(e),
Ok(Async::NotReady) => return false,
}
}
_ => return true,
};
*self = InFlight::Done(res);
true
}
fn unwrap_done(self) -> Result<F::Item, F::Error> {
match self {
InFlight::Done(res) => res,
_ => panic!("future is not ready"),
}
}
}