1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153

use BindClient;
use super::{RequestId, Multiplex};
use super::lift::{LiftBind, LiftTransport};
use simple::LiftProto;

use std::{fmt, io};

use streaming::{self, Message};
use streaming::multiplex::StreamingMultiplex;
use tokio_service::Service;
use futures::{stream, Stream, Sink, Future, IntoFuture, Poll};
use futures::future::Executor;

type MyStream<E> = stream::Empty<(), E>;

/// An multiplexed client protocol.
///
/// The `T` parameter is used for the I/O object used to communicate, which is
/// supplied in `bind_transport`.
///
/// For simple protocols, the `Self` type is often a unit struct. In more
/// advanced cases, `Self` may contain configuration information that is used
/// for setting up the transport in `bind_transport`.
pub trait ClientProto<T: 'static>: 'static {
    /// Request messages.
    type Request: 'static;

    /// Response messages.
    type Response: 'static;

    /// The message transport, which usually take `T` as a parameter.
    ///
    /// An easy way to build a transport is to use `tokio_core::io::Framed`
    /// together with a `Codec`; in that case, the transport type is
    /// `Framed<T, YourCodec>`. See the crate docs for an example.
    type Transport: 'static +
        Stream<Item = (RequestId, Self::Response), Error = io::Error> +
        Sink<SinkItem = (RequestId, Self::Request), SinkError = io::Error>;

    /// A future for initializing a transport from an I/O object.
    ///
    /// In simple cases, `Result<Self::Transport, Self::Error>` often suffices.
    type BindTransport: IntoFuture<Item = Self::Transport, Error = io::Error>;

    /// Build a transport from the given I/O object, using `self` for any
    /// configuration.
    ///
    /// An easy way to build a transport is to use `tokio_core::io::Framed`
    /// together with a `Codec`; in that case, `bind_transport` is just
    /// `io.framed(YourCodec)`. See the crate docs for an example.
    fn bind_transport(&self, io: T) -> Self::BindTransport;
}

impl<T: 'static, P: ClientProto<T>> BindClient<Multiplex, T> for P {
    type ServiceRequest = P::Request;
    type ServiceResponse = P::Response;
    type ServiceError = io::Error;

    type BindClient = ClientService<T, P>;

    fn bind_client<E>(&self, executor: &E, io: T) -> Self::BindClient
        where E: Executor<Box<Future<Item = (), Error = ()>>>,
    {
        ClientService {
            inner: BindClient::<StreamingMultiplex<MyStream<io::Error>>, T>::bind_client(
                LiftProto::from_ref(self), executor, io
            )
        }
    }
}

impl<T, P> streaming::multiplex::ClientProto<T> for LiftProto<P> where
    T: 'static, P: ClientProto<T>
{
    type Request = P::Request;
    type RequestBody = ();

    type Response = P::Response;
    type ResponseBody = ();

    type Error = io::Error;

    type Transport = LiftTransport<P::Transport, io::Error>;
    type BindTransport = LiftBind<T, <P::BindTransport as IntoFuture>::Future, io::Error>;

    fn bind_transport(&self, io: T) -> Self::BindTransport {
        LiftBind::lift(ClientProto::bind_transport(self.lower(), io).into_future())
    }
}

/// Client `Service` for simple multiplex protocols
pub struct ClientService<T, P> where T: 'static, P: ClientProto<T> {
    inner: <LiftProto<P> as BindClient<StreamingMultiplex<MyStream<io::Error>>, T>>::BindClient
}

impl<T, P> Service for ClientService<T, P> where T: 'static, P: ClientProto<T> {
    type Request = P::Request;
    type Response = P::Response;
    type Error = io::Error;
    type Future = ClientFuture<T, P>;

    fn call(&self, req: P::Request) -> Self::Future {
        ClientFuture {
            inner: self.inner.call(Message::WithoutBody(req))
        }
    }
}

impl<T, P> Clone for ClientService<T, P> where T: 'static, P: ClientProto<T> {
    fn clone(&self) -> Self {
        ClientService {
            inner: self.inner.clone(),
        }
    }
}

impl<T, P> fmt::Debug for ClientService<T, P>
    where T: 'static + fmt::Debug,
          P: ClientProto<T> + fmt::Debug
{
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        write!(f, "ClientService {{ ... }}")
    }
}

/// Future returned by a call to [`ClientService`].
///
/// [`ClientService`]: struct.ClientService.html
pub struct ClientFuture<T, P> where T: 'static, P: ClientProto<T> {
    inner: <<LiftProto<P> as BindClient<StreamingMultiplex<MyStream<io::Error>>, T>>::BindClient
            as Service>::Future
}

impl<T, P> Future for ClientFuture<T, P>  where T: 'static, P: ClientProto<T> {
    type Item = P::Response;
    type Error = io::Error;

    fn poll(&mut self) -> Poll<Self::Item, Self::Error> {
        match try_ready!(self.inner.poll()) {
            Message::WithoutBody(msg) => Ok(msg.into()),
            Message::WithBody(..) => panic!("bodies not supported"),
        }
    }
}

impl<T, P> fmt::Debug for ClientFuture<T, P>
    where T: 'static + fmt::Debug,
          P: ClientProto<T> + fmt::Debug
{
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        write!(f, "ClientService {{ ... }}")
    }
}