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//! Lower-level client connection API.
//!
//! The types in this module are to provide a lower-level API based around a
//! single connection. Connecting to a host, pooling connections, and the like
//! are not handled at this level. This module provides the building blocks to
//! customize those things externally.
//!
//! If don't have need to manage connections yourself, consider using the
//! higher-level [Client](super) API.
use std::fmt;
use std::marker::PhantomData;
use std::mem;
use bytes::Bytes;
use futures::{Async, Future, Poll};
use futures::future::{self, Either};
use tokio_io::{AsyncRead, AsyncWrite};
use body::Payload;
use common::Exec;
use upgrade::Upgraded;
use proto;
use super::dispatch;
use {Body, Request, Response};
type Http1Dispatcher<T, B, R> = proto::dispatch::Dispatcher<
proto::dispatch::Client<B>,
B,
T,
R,
>;
type ConnEither<T, B> = Either<
Http1Dispatcher<T, B, proto::h1::ClientTransaction>,
proto::h2::Client<T, B>,
>;
/// Returns a `Handshake` future over some IO.
///
/// This is a shortcut for `Builder::new().handshake(io)`.
pub fn handshake<T>(io: T) -> Handshake<T, ::Body>
where
T: AsyncRead + AsyncWrite + Send + 'static,
{
Builder::new()
.handshake(io)
}
/// The sender side of an established connection.
pub struct SendRequest<B> {
dispatch: dispatch::Sender<Request<B>, Response<Body>>,
}
/// A future that processes all HTTP state for the IO object.
///
/// In most cases, this should just be spawned into an executor, so that it
/// can process incoming and outgoing messages, notice hangups, and the like.
#[must_use = "futures do nothing unless polled"]
pub struct Connection<T, B>
where
T: AsyncRead + AsyncWrite + Send + 'static,
B: Payload + 'static,
{
inner: Option<ConnEither<T, B>>,
}
/// A builder to configure an HTTP connection.
///
/// After setting options, the builder is used to create a `Handshake` future.
#[derive(Clone, Debug)]
pub struct Builder {
exec: Exec,
h1_writev: bool,
h1_title_case_headers: bool,
http2: bool,
}
/// A future setting up HTTP over an IO object.
///
/// If successful, yields a `(SendRequest, Connection)` pair.
#[must_use = "futures do nothing unless polled"]
pub struct Handshake<T, B> {
builder: Builder,
io: Option<T>,
_marker: PhantomData<B>,
}
/// A future returned by `SendRequest::send_request`.
///
/// Yields a `Response` if successful.
#[must_use = "futures do nothing unless polled"]
pub struct ResponseFuture {
// for now, a Box is used to hide away the internal `B`
// that can be returned if canceled
inner: Box<Future<Item=Response<Body>, Error=::Error> + Send>,
}
/// Deconstructed parts of a `Connection`.
///
/// This allows taking apart a `Connection` at a later time, in order to
/// reclaim the IO object, and additional related pieces.
#[derive(Debug)]
pub struct Parts<T> {
/// The original IO object used in the handshake.
pub io: T,
/// A buffer of bytes that have been read but not processed as HTTP.
///
/// For instance, if the `Connection` is used for an HTTP upgrade request,
/// it is possible the server sent back the first bytes of the new protocol
/// along with the response upgrade.
///
/// You will want to check for any existing bytes if you plan to continue
/// communicating on the IO object.
pub read_buf: Bytes,
_inner: (),
}
// ========== internal client api
/// A `Future` for when `SendRequest::poll_ready()` is ready.
// FIXME: allow() required due to `impl Trait` leaking types to this lint
#[allow(missing_debug_implementations)]
#[must_use = "futures do nothing unless polled"]
pub(super) struct WhenReady<B> {
tx: Option<SendRequest<B>>,
}
// A `SendRequest` that can be cloned to send HTTP2 requests.
// private for now, probably not a great idea of a type...
#[must_use = "futures do nothing unless polled"]
pub(super) struct Http2SendRequest<B> {
dispatch: dispatch::UnboundedSender<Request<B>, Response<Body>>,
}
// ===== impl SendRequest
impl<B> SendRequest<B>
{
/// Polls to determine whether this sender can be used yet for a request.
///
/// If the associated connection is closed, this returns an Error.
pub fn poll_ready(&mut self) -> Poll<(), ::Error> {
self.dispatch.poll_ready()
}
pub(super) fn when_ready(self) -> WhenReady<B> {
WhenReady {
tx: Some(self),
}
}
pub(super) fn is_ready(&self) -> bool {
self.dispatch.is_ready()
}
pub(super) fn is_closed(&self) -> bool {
self.dispatch.is_closed()
}
pub(super) fn into_http2(self) -> Http2SendRequest<B> {
Http2SendRequest {
dispatch: self.dispatch.unbound(),
}
}
}
impl<B> SendRequest<B>
where
B: Payload + 'static,
{
/// Sends a `Request` on the associated connection.
///
/// Returns a future that if successful, yields the `Response`.
///
/// # Note
///
/// There are some key differences in what automatic things the `Client`
/// does for you that will not be done here:
///
/// - `Client` requires absolute-form `Uri`s, since the scheme and
/// authority are needed to connect. They aren't required here.
/// - Since the `Client` requires absolute-form `Uri`s, it can add
/// the `Host` header based on it. You must add a `Host` header yourself
/// before calling this method.
/// - Since absolute-form `Uri`s are not required, if received, they will
/// be serialized as-is.
///
/// # Example
///
/// ```
/// # extern crate futures;
/// # extern crate hyper;
/// # extern crate http;
/// # use http::header::HOST;
/// # use hyper::client::conn::SendRequest;
/// # use hyper::Body;
/// use futures::Future;
/// use hyper::Request;
///
/// # fn doc(mut tx: SendRequest<Body>) {
/// // build a Request
/// let req = Request::builder()
/// .uri("/foo/bar")
/// .header(HOST, "hyper.rs")
/// .body(Body::empty())
/// .unwrap();
///
/// // send it and get a future back
/// let fut = tx.send_request(req)
/// .map(|res| {
/// // got the Response
/// assert!(res.status().is_success());
/// });
/// # drop(fut);
/// # }
/// # fn main() {}
/// ```
pub fn send_request(&mut self, req: Request<B>) -> ResponseFuture {
let inner = match self.dispatch.send(req) {
Ok(rx) => {
Either::A(rx.then(move |res| {
match res {
Ok(Ok(res)) => Ok(res),
Ok(Err(err)) => Err(err),
// this is definite bug if it happens, but it shouldn't happen!
Err(_) => panic!("dispatch dropped without returning error"),
}
}))
},
Err(_req) => {
debug!("connection was not ready");
let err = ::Error::new_canceled(Some("connection was not ready"));
Either::B(future::err(err))
}
};
ResponseFuture {
inner: Box::new(inner),
}
}
pub(crate) fn send_request_retryable(&mut self, req: Request<B>) -> impl Future<Item = Response<Body>, Error = (::Error, Option<Request<B>>)>
where
B: Send,
{
match self.dispatch.try_send(req) {
Ok(rx) => {
Either::A(rx.then(move |res| {
match res {
Ok(Ok(res)) => Ok(res),
Ok(Err(err)) => Err(err),
// this is definite bug if it happens, but it shouldn't happen!
Err(_) => panic!("dispatch dropped without returning error"),
}
}))
},
Err(req) => {
debug!("connection was not ready");
let err = ::Error::new_canceled(Some("connection was not ready"));
Either::B(future::err((err, Some(req))))
}
}
}
}
/* TODO(0.12.0): when we change from tokio-service to tower.
impl<T, B> Service for SendRequest<T, B> {
type Request = Request<B>;
type Response = Response;
type Error = ::Error;
type Future = ResponseFuture;
fn call(&self, req: Self::Request) -> Self::Future {
}
}
*/
impl<B> fmt::Debug for SendRequest<B> {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
f.debug_struct("SendRequest")
.finish()
}
}
// ===== impl Http2SendRequest
impl<B> Http2SendRequest<B> {
pub(super) fn is_ready(&self) -> bool {
self.dispatch.is_ready()
}
pub(super) fn is_closed(&self) -> bool {
self.dispatch.is_closed()
}
}
impl<B> Http2SendRequest<B>
where
B: Payload + 'static,
{
pub(super) fn send_request_retryable(&mut self, req: Request<B>) -> impl Future<Item=Response<Body>, Error=(::Error, Option<Request<B>>)>
where
B: Send,
{
match self.dispatch.try_send(req) {
Ok(rx) => {
Either::A(rx.then(move |res| {
match res {
Ok(Ok(res)) => Ok(res),
Ok(Err(err)) => Err(err),
// this is definite bug if it happens, but it shouldn't happen!
Err(_) => panic!("dispatch dropped without returning error"),
}
}))
},
Err(req) => {
debug!("connection was not ready");
let err = ::Error::new_canceled(Some("connection was not ready"));
Either::B(future::err((err, Some(req))))
}
}
}
}
impl<B> fmt::Debug for Http2SendRequest<B> {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
f.debug_struct("Http2SendRequest")
.finish()
}
}
impl<B> Clone for Http2SendRequest<B> {
fn clone(&self) -> Self {
Http2SendRequest {
dispatch: self.dispatch.clone(),
}
}
}
// ===== impl Connection
impl<T, B> Connection<T, B>
where
T: AsyncRead + AsyncWrite + Send + 'static,
B: Payload + 'static,
{
/// Return the inner IO object, and additional information.
///
/// Only works for HTTP/1 connections. HTTP/2 connections will panic.
pub fn into_parts(self) -> Parts<T> {
let (io, read_buf, _) = match self.inner.expect("already upgraded") {
Either::A(h1) => h1.into_inner(),
Either::B(_h2) => {
panic!("http2 cannot into_inner");
}
};
Parts {
io: io,
read_buf: read_buf,
_inner: (),
}
}
/// Poll the connection for completion, but without calling `shutdown`
/// on the underlying IO.
///
/// This is useful to allow running a connection while doing an HTTP
/// upgrade. Once the upgrade is completed, the connection would be "done",
/// but it is not desired to actally shutdown the IO object. Instead you
/// would take it back using `into_parts`.
pub fn poll_without_shutdown(&mut self) -> Poll<(), ::Error> {
match self.inner.as_mut().expect("already upgraded") {
&mut Either::A(ref mut h1) => {
h1.poll_without_shutdown()
},
&mut Either::B(ref mut h2) => {
h2.poll().map(|x| x.map(|_| ()))
}
}
}
}
impl<T, B> Future for Connection<T, B>
where
T: AsyncRead + AsyncWrite + Send + 'static,
B: Payload + 'static,
{
type Item = ();
type Error = ::Error;
fn poll(&mut self) -> Poll<Self::Item, Self::Error> {
match try_ready!(self.inner.poll()) {
Some(proto::Dispatched::Shutdown) |
None => {
Ok(Async::Ready(()))
},
Some(proto::Dispatched::Upgrade(pending)) => {
let h1 = match mem::replace(&mut self.inner, None) {
Some(Either::A(h1)) => h1,
_ => unreachable!("Upgrade expects h1"),
};
let (io, buf, _) = h1.into_inner();
pending.fulfill(Upgraded::new(Box::new(io), buf));
Ok(Async::Ready(()))
}
}
}
}
impl<T, B> fmt::Debug for Connection<T, B>
where
T: AsyncRead + AsyncWrite + fmt::Debug + Send + 'static,
B: Payload + 'static,
{
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
f.debug_struct("Connection")
.finish()
}
}
// ===== impl Builder
impl Builder {
/// Creates a new connection builder.
#[inline]
pub fn new() -> Builder {
Builder {
exec: Exec::Default,
h1_writev: true,
h1_title_case_headers: false,
http2: false,
}
}
pub(super) fn exec(&mut self, exec: Exec) -> &mut Builder {
self.exec = exec;
self
}
pub(super) fn h1_writev(&mut self, enabled: bool) -> &mut Builder {
self.h1_writev = enabled;
self
}
pub(super) fn h1_title_case_headers(&mut self, enabled: bool) -> &mut Builder {
self.h1_title_case_headers = enabled;
self
}
/// Sets whether HTTP2 is required.
///
/// Default is false.
pub fn http2_only(&mut self, enabled: bool) -> &mut Builder {
self.http2 = enabled;
self
}
/// Constructs a connection with the configured options and IO.
#[inline]
pub fn handshake<T, B>(&self, io: T) -> Handshake<T, B>
where
T: AsyncRead + AsyncWrite + Send + 'static,
B: Payload + 'static,
{
Handshake {
builder: self.clone(),
io: Some(io),
_marker: PhantomData,
}
}
}
// ===== impl Handshake
impl<T, B> Future for Handshake<T, B>
where
T: AsyncRead + AsyncWrite + Send + 'static,
B: Payload + 'static,
{
type Item = (SendRequest<B>, Connection<T, B>);
type Error = ::Error;
fn poll(&mut self) -> Poll<Self::Item, Self::Error> {
let io = self.io.take().expect("polled more than once");
let (tx, rx) = dispatch::channel();
let either = if !self.builder.http2 {
let mut conn = proto::Conn::new(io);
if !self.builder.h1_writev {
conn.set_write_strategy_flatten();
}
if self.builder.h1_title_case_headers {
conn.set_title_case_headers();
}
let cd = proto::h1::dispatch::Client::new(rx);
let dispatch = proto::h1::Dispatcher::new(cd, conn);
Either::A(dispatch)
} else {
let h2 = proto::h2::Client::new(io, rx, self.builder.exec.clone());
Either::B(h2)
};
Ok(Async::Ready((
SendRequest {
dispatch: tx,
},
Connection {
inner: Some(either),
},
)))
}
}
impl<T, B> fmt::Debug for Handshake<T, B> {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
f.debug_struct("Handshake")
.finish()
}
}
// ===== impl ResponseFuture
impl Future for ResponseFuture {
type Item = Response<Body>;
type Error = ::Error;
#[inline]
fn poll(&mut self) -> Poll<Self::Item, Self::Error> {
self.inner.poll()
}
}
impl fmt::Debug for ResponseFuture {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
f.debug_struct("ResponseFuture")
.finish()
}
}
// ===== impl WhenReady
impl<B> Future for WhenReady<B> {
type Item = SendRequest<B>;
type Error = ::Error;
fn poll(&mut self) -> Poll<Self::Item, Self::Error> {
let mut tx = self.tx.take().expect("polled after complete");
match tx.poll_ready()? {
Async::Ready(()) => Ok(Async::Ready(tx)),
Async::NotReady => {
self.tx = Some(tx);
Ok(Async::NotReady)
}
}
}
}
// assert trait markers
trait AssertSend: Send {}
trait AssertSendSync: Send + Sync {}
#[doc(hidden)]
impl<B: Send> AssertSendSync for SendRequest<B> {}
#[doc(hidden)]
impl<T: Send, B: Send> AssertSend for Connection<T, B>
where
T: AsyncRead + AsyncWrite + Send + 'static,
B: Payload + 'static,
{}
#[doc(hidden)]
impl<T: Send + Sync, B: Send + Sync> AssertSendSync for Connection<T, B>
where
T: AsyncRead + AsyncWrite + Send + 'static,
B: Payload + 'static,
B::Data: Send + Sync + 'static,
{}
#[doc(hidden)]
impl AssertSendSync for Builder {}
#[doc(hidden)]
impl AssertSend for ResponseFuture {}