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
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
//! 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 std::sync::Arc;

use bytes::Bytes;
use futures::{Async, Future, Poll};
use futures::future::{self, Either, Executor};
use h2;
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 {
    pub(super) exec: Exec,
    h1_writev: bool,
    h1_title_case_headers: bool,
    h1_read_buf_exact_size: Option<usize>,
    h1_max_buf_size: Option<usize>,
    http2: bool,
    h2_builder: h2::client::Builder,
}

/// 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<dyn 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().with("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().with("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().with("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`.
    ///
    /// Use [`poll_fn`](https://docs.rs/futures/0.1.25/futures/future/fn.poll_fn.html)
    /// and [`try_ready!`](https://docs.rs/futures/0.1.25/futures/macro.try_ready.html)
    /// to work with this function; or use the `without_shutdown` wrapper.
    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(|_| ()))
            }
        }
    }

    /// Prevent shutdown of the underlying IO object at the end of service the request,
    /// instead run `into_parts`. This is a convenience wrapper over `poll_without_shutdown`.
    pub fn without_shutdown(self) -> impl Future<Item=Parts<T>, Error=::Error> {
        let mut conn = Some(self);
        ::futures::future::poll_fn(move || -> ::Result<_> {
            try_ready!(conn.as_mut().unwrap().poll_without_shutdown());
            Ok(conn.take().unwrap().into_parts().into())
        })
    }
}

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 {
        let mut h2_builder = h2::client::Builder::default();
        h2_builder.enable_push(false);

        Builder {
            exec: Exec::Default,
            h1_writev: true,
            h1_read_buf_exact_size: None,
            h1_title_case_headers: false,
            h1_max_buf_size: None,
            http2: false,
            h2_builder,
        }
    }

    /// Provide an executor to execute background HTTP2 tasks.
    pub fn executor<E>(&mut self, exec: E) -> &mut Builder
    where
        E: Executor<Box<dyn Future<Item=(), Error=()> + Send>> + Send + Sync + 'static,
    {
        self.exec = Exec::Executor(Arc::new(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
    }

    pub(super) fn h1_read_buf_exact_size(&mut self, sz: Option<usize>) -> &mut Builder {
        self.h1_read_buf_exact_size = sz;
        self.h1_max_buf_size = None;
        self
    }

    pub(super) fn h1_max_buf_size(&mut self, max: usize) -> &mut Self {
        assert!(
            max >= proto::h1::MINIMUM_MAX_BUFFER_SIZE,
            "the max_buf_size cannot be smaller than the minimum that h1 specifies."
        );

        self.h1_max_buf_size = Some(max);
        self.h1_read_buf_exact_size = None;
        self
    }

    /// Sets whether HTTP2 is required.
    ///
    /// Default is false.
    pub fn http2_only(&mut self, enabled: bool) -> &mut Builder {
        self.http2 = enabled;
        self
    }

    /// Sets the [`SETTINGS_INITIAL_WINDOW_SIZE`][spec] option for HTTP2
    /// stream-level flow control.
    ///
    /// Default is 65,535
    ///
    /// [spec]: https://http2.github.io/http2-spec/#SETTINGS_INITIAL_WINDOW_SIZE
    pub fn http2_initial_stream_window_size(&mut self, sz: impl Into<Option<u32>>) -> &mut Self {
        if let Some(sz) = sz.into() {
            self.h2_builder.initial_window_size(sz);
        }
        self
    }

    /// Sets the max connection-level flow control for HTTP2
    ///
    /// Default is 65,535
    pub fn http2_initial_connection_window_size(&mut self, sz: impl Into<Option<u32>>) -> &mut Self {
        if let Some(sz) = sz.into() {
            self.h2_builder.initial_connection_window_size(sz);
        }
        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,
    {
        trace!("client handshake HTTP/{}", if self.http2 { 2 } else { 1 });
        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();
            }
            if let Some(sz) = self.builder.h1_read_buf_exact_size {
                conn.set_read_buf_exact_size(sz);
            }
            if let Some(max) = self.builder.h1_max_buf_size {
                conn.set_max_buf_size(max);
            }
            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.h2_builder, 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 {}