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

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

use streaming::{self, Message};
use streaming::pipeline::StreamingPipeline;
use tokio_core::reactor::Handle;
use tokio_service::Service;
use futures::{stream, Stream, Sink, Future, Poll, IntoFuture};
use std::io;

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

/// A pipelined 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;

    /// Errors produced by the service.
    type Error: From<io::Error> + 'static;

    /// The message transport, which works with I/O objects of type `T`.
    ///
    /// 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 = Self::Response, Error = io::Error> +
        Sink<SinkItem = 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<Pipeline, T> for P {
    type ServiceRequest = P::Request;
    type ServiceResponse = P::Response;
    type ServiceError = P::Error;

    type BindClient = ClientService<T, P>;

    fn bind_client(&self, handle: &Handle, io: T) -> Self::BindClient {
        ClientService {
            inner: BindClient::<StreamingPipeline<MyStream<P::Error>>, T>::bind_client(
                LiftProto::from_ref(self), handle, io
            )
        }
    }
}

impl<T, P> streaming::pipeline::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 = P::Error;

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

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

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

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

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

pub struct ClientFuture<T, P> where T: 'static, P: ClientProto<T> {
    inner: <<LiftProto<P> as BindClient<StreamingPipeline<MyStream<P::Error>>, T>>::BindClient
            as Service>::Future
}

impl<T, P> Future for ClientFuture<T, P> where P: ClientProto<T> {
    type Item = P::Response;
    type Error = P::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"),
        }
    }
}