Files
tarpc/rpc/src/transport/mod.rs
2019-02-26 09:32:41 -08:00

122 lines
3.1 KiB
Rust

// Copyright 2018 Google LLC
//
// Use of this source code is governed by an MIT-style
// license that can be found in the LICENSE file or at
// https://opensource.org/licenses/MIT.
//! Provides a [`Transport`] trait as well as implementations.
//!
//! The rpc crate is transport- and protocol-agnostic. Any transport that impls [`Transport`]
//! can be plugged in, using whatever protocol it wants.
use futures::prelude::*;
use std::{
io,
net::SocketAddr,
pin::Pin,
task::{Poll, Waker},
};
pub mod channel;
/// A bidirectional stream ([`Sink`] + [`Stream`]) of messages.
pub trait Transport
where
Self: Stream<Item = io::Result<<Self as Transport>::Item>>,
Self: Sink<SinkItem = <Self as Transport>::SinkItem, SinkError = io::Error>,
{
/// The type read off the transport.
type Item;
/// The type written to the transport.
type SinkItem;
/// The address of the remote peer this transport is in communication with.
fn peer_addr(&self) -> io::Result<SocketAddr>;
/// The address of the local half of this transport.
fn local_addr(&self) -> io::Result<SocketAddr>;
}
/// Returns a new Transport backed by the given Stream + Sink and connecting addresses.
pub fn new<S, Item>(
inner: S,
peer_addr: SocketAddr,
local_addr: SocketAddr,
) -> impl Transport<Item = Item, SinkItem = S::SinkItem>
where
S: Stream<Item = io::Result<Item>>,
S: Sink<SinkError = io::Error>,
{
TransportShim {
inner,
peer_addr,
local_addr,
}
}
/// A transport created by adding peers to a Stream + Sink.
#[derive(Debug)]
struct TransportShim<S> {
peer_addr: SocketAddr,
local_addr: SocketAddr,
inner: S,
}
impl<S> TransportShim<S> {
pin_utils::unsafe_pinned!(inner: S);
}
impl<S> Stream for TransportShim<S>
where
S: Stream,
{
type Item = S::Item;
fn poll_next(self: Pin<&mut Self>, waker: &Waker) -> Poll<Option<S::Item>> {
self.inner().poll_next(waker)
}
}
impl<S> Sink for TransportShim<S>
where
S: Sink,
{
type SinkItem = S::SinkItem;
type SinkError = S::SinkError;
fn start_send(self: Pin<&mut Self>, item: S::SinkItem) -> Result<(), S::SinkError> {
self.inner().start_send(item)
}
fn poll_ready(self: Pin<&mut Self>, waker: &Waker) -> Poll<Result<(), S::SinkError>> {
self.inner().poll_ready(waker)
}
fn poll_flush(self: Pin<&mut Self>, waker: &Waker) -> Poll<Result<(), S::SinkError>> {
self.inner().poll_flush(waker)
}
fn poll_close(self: Pin<&mut Self>, waker: &Waker) -> Poll<Result<(), S::SinkError>> {
self.inner().poll_close(waker)
}
}
impl<S, Item> Transport for TransportShim<S>
where
S: Stream + Sink,
Self: Stream<Item = io::Result<Item>>,
Self: Sink<SinkItem = S::SinkItem, SinkError = io::Error>,
{
type Item = Item;
type SinkItem = S::SinkItem;
/// The address of the remote peer this transport is in communication with.
fn peer_addr(&self) -> io::Result<SocketAddr> {
Ok(self.peer_addr)
}
/// The address of the local half of this transport.
fn local_addr(&self) -> io::Result<SocketAddr> {
Ok(self.local_addr)
}
}