/rust/registry/src/index.crates.io-6f17d22bba15001f/tokio-test-0.4.4/src/io.rs

Source (jump to first uncovered line)
#![cfg(not(loom))]

//! A mock type implementing [`AsyncRead`] and [`AsyncWrite`].
//!
//!
//! # Overview
//!
//! Provides a type that implements [`AsyncRead`] + [`AsyncWrite`] that can be configured
//! to handle an arbitrary sequence of read and write operations. This is useful
//! for writing unit tests for networking services as using an actual network
//! type is fairly non deterministic.
//!
//! # Usage
//!
//! Attempting to write data that the mock isn't expecting will result in a
//! panic.
//!
//! [`AsyncRead`]: tokio::io::AsyncRead
//! [`AsyncWrite`]: tokio::io::AsyncWrite

use tokio::io::{AsyncRead, AsyncWrite, ReadBuf};
use tokio::sync::mpsc;
use tokio::time::{self, Duration, Instant, Sleep};
use tokio_stream::wrappers::UnboundedReceiverStream;

use futures_core::{ready, Stream};
use std::collections::VecDeque;
use std::fmt;
use std::future::Future;
use std::pin::Pin;
use std::sync::Arc;
use std::task::{self, Poll, Waker};
use std::{cmp, io};

/// An I/O object that follows a predefined script.
///
/// This value is created by `Builder` and implements `AsyncRead` + `AsyncWrite`. It
/// follows the scenario described by the builder and panics otherwise.
#[derive(Debug)]
pub struct Mock {
    inner: Inner,
}

/// A handle to send additional actions to the related `Mock`.
#[derive(Debug)]
pub struct Handle {
    tx: mpsc::UnboundedSender<Action>,
}

/// Builds `Mock` instances.
#[derive(Debug, Clone, Default)]
pub struct Builder {
    // Sequence of actions for the Mock to take
    actions: VecDeque<Action>,
}

#[derive(Debug, Clone)]
enum Action {
    Read(Vec<u8>),
    Write(Vec<u8>),
    Wait(Duration),
    // Wrapped in Arc so that Builder can be cloned and Send.
    // Mock is not cloned as does not need to check Rc for ref counts.
    ReadError(Option<Arc<io::Error>>),
    WriteError(Option<Arc<io::Error>>),
}

struct Inner {
    actions: VecDeque<Action>,
    waiting: Option<Instant>,
    sleep: Option<Pin<Box<Sleep>>>,
    read_wait: Option<Waker>,
    rx: UnboundedReceiverStream<Action>,
}

impl Builder {
    /// Return a new, empty `Builder`.
    pub fn new() -> Self {
        Self::default()
    }

    /// Sequence a `read` operation.
    ///
    /// The next operation in the mock's script will be to expect a `read` call
    /// and return `buf`.
    pub fn read(&mut self, buf: &[u8]) -> &mut Self {
        self.actions.push_back(Action::Read(buf.into()));
        self
    }

    /// Sequence a `read` operation that produces an error.
    ///
    /// The next operation in the mock's script will be to expect a `read` call
    /// and return `error`.
    pub fn read_error(&mut self, error: io::Error) -> &mut Self {
        let error = Some(error.into());
        self.actions.push_back(Action::ReadError(error));
        self
    }

    /// Sequence a `write` operation.
    ///
    /// The next operation in the mock's script will be to expect a `write`
    /// call.
    pub fn write(&mut self, buf: &[u8]) -> &mut Self {
        self.actions.push_back(Action::Write(buf.into()));
        self
    }

    /// Sequence a `write` operation that produces an error.
    ///
    /// The next operation in the mock's script will be to expect a `write`
    /// call that provides `error`.
    pub fn write_error(&mut self, error: io::Error) -> &mut Self {
        let error = Some(error.into());
        self.actions.push_back(Action::WriteError(error));
        self
    }

    /// Sequence a wait.
    ///
    /// The next operation in the mock's script will be to wait without doing so
    /// for `duration` amount of time.
    pub fn wait(&mut self, duration: Duration) -> &mut Self {
        let duration = cmp::max(duration, Duration::from_millis(1));
        self.actions.push_back(Action::Wait(duration));
        self
    }

    /// Build a `Mock` value according to the defined script.
    pub fn build(&mut self) -> Mock {
        let (mock, _) = self.build_with_handle();
        mock
    }

    /// Build a `Mock` value paired with a handle
    pub fn build_with_handle(&mut self) -> (Mock, Handle) {
        let (inner, handle) = Inner::new(self.actions.clone());

        let mock = Mock { inner };

        (mock, handle)
    }
}

impl Handle {
    /// Sequence a `read` operation.
    ///
    /// The next operation in the mock's script will be to expect a `read` call
    /// and return `buf`.
    pub fn read(&mut self, buf: &[u8]) -> &mut Self {
        self.tx.send(Action::Read(buf.into())).unwrap();
        self
    }

    /// Sequence a `read` operation error.
    ///
    /// The next operation in the mock's script will be to expect a `read` call
    /// and return `error`.
    pub fn read_error(&mut self, error: io::Error) -> &mut Self {
        let error = Some(error.into());
        self.tx.send(Action::ReadError(error)).unwrap();
        self
    }

    /// Sequence a `write` operation.
    ///
    /// The next operation in the mock's script will be to expect a `write`
    /// call.
    pub fn write(&mut self, buf: &[u8]) -> &mut Self {
        self.tx.send(Action::Write(buf.into())).unwrap();
        self
    }

    /// Sequence a `write` operation error.
    ///
    /// The next operation in the mock's script will be to expect a `write`
    /// call error.
    pub fn write_error(&mut self, error: io::Error) -> &mut Self {
        let error = Some(error.into());
        self.tx.send(Action::WriteError(error)).unwrap();
        self
    }
}

impl Inner {
    fn new(actions: VecDeque<Action>) -> (Inner, Handle) {
        let (tx, rx) = mpsc::unbounded_channel();

        let rx = UnboundedReceiverStream::new(rx);

        let inner = Inner {
            actions,
            sleep: None,
            read_wait: None,
            rx,
            waiting: None,
        };

        let handle = Handle { tx };

        (inner, handle)
    }

    fn poll_action(&mut self, cx: &mut task::Context<'_>) -> Poll<Option<Action>> {
        Pin::new(&mut self.rx).poll_next(cx)
    }

    fn read(&mut self, dst: &mut ReadBuf<'_>) -> io::Result<()> {
        match self.action() {
            Some(&mut Action::Read(ref mut data)) => {
                // Figure out how much to copy
                let n = cmp::min(dst.remaining(), data.len());

                // Copy the data into the `dst` slice
                dst.put_slice(&data[..n]);

                // Drain the data from the source
                data.drain(..n);

                Ok(())
            }
            Some(&mut Action::ReadError(ref mut err)) => {
                // As the
                let err = err.take().expect("Should have been removed from actions.");
                let err = Arc::try_unwrap(err).expect("There are no other references.");
                Err(err)
            }
            Some(_) => {
                // Either waiting or expecting a write
                Err(io::ErrorKind::WouldBlock.into())
            }
            None => Ok(()),
        }
    }

    fn write(&mut self, mut src: &[u8]) -> io::Result<usize> {
        let mut ret = 0;

        if self.actions.is_empty() {
            return Err(io::ErrorKind::BrokenPipe.into());
        }

        if let Some(&mut Action::Wait(..)) = self.action() {
            return Err(io::ErrorKind::WouldBlock.into());
        }

        if let Some(&mut Action::WriteError(ref mut err)) = self.action() {
            let err = err.take().expect("Should have been removed from actions.");
            let err = Arc::try_unwrap(err).expect("There are no other references.");
            return Err(err);
        }

        for i in 0..self.actions.len() {
            match self.actions[i] {
                Action::Write(ref mut expect) => {
                    let n = cmp::min(src.len(), expect.len());

                    assert_eq!(&src[..n], &expect[..n]);

                    // Drop data that was matched
                    expect.drain(..n);
                    src = &src[n..];

                    ret += n;

                    if src.is_empty() {
                        return Ok(ret);
                    }
                }
                Action::Wait(..) | Action::WriteError(..) => {
                    break;
                }
                _ => {}
            }

            // TODO: remove write
        }

        Ok(ret)
    }

    fn remaining_wait(&mut self) -> Option<Duration> {
        match self.action() {
            Some(&mut Action::Wait(dur)) => Some(dur),
            _ => None,
        }
    }

    fn action(&mut self) -> Option<&mut Action> {
        loop {
            if self.actions.is_empty() {
                return None;
            }

            match self.actions[0] {
                Action::Read(ref mut data) => {
                    if !data.is_empty() {
                        break;
                    }
                }
                Action::Write(ref mut data) => {
                    if !data.is_empty() {
                        break;
                    }
                }
                Action::Wait(ref mut dur) => {
                    if let Some(until) = self.waiting {
                        let now = Instant::now();

                        if now < until {
                            break;
                        } else {
                            self.waiting = None;
                        }
                    } else {
                        self.waiting = Some(Instant::now() + *dur);
                        break;
                    }
                }
                Action::ReadError(ref mut error) | Action::WriteError(ref mut error) => {
                    if error.is_some() {
                        break;
                    }
                }
            }

            let _action = self.actions.pop_front();
        }

        self.actions.front_mut()
    }
}

// ===== impl Inner =====

impl Mock {
    fn maybe_wakeup_reader(&mut self) {
        match self.inner.action() {
            Some(&mut Action::Read(_)) | Some(&mut Action::ReadError(_)) | None => {
                if let Some(waker) = self.inner.read_wait.take() {
                    waker.wake();
                }
            }
            _ => {}
        }
    }
}

impl AsyncRead for Mock {
    fn poll_read(
        mut self: Pin<&mut Self>,
        cx: &mut task::Context<'_>,
        buf: &mut ReadBuf<'_>,
    ) -> Poll<io::Result<()>> {
        loop {
            if let Some(ref mut sleep) = self.inner.sleep {
                ready!(Pin::new(sleep).poll(cx));
            }

            // If a sleep is set, it has already fired
            self.inner.sleep = None;

            // Capture 'filled' to monitor if it changed
            let filled = buf.filled().len();

            match self.inner.read(buf) {
                Err(ref e) if e.kind() == io::ErrorKind::WouldBlock => {
                    if let Some(rem) = self.inner.remaining_wait() {
                        let until = Instant::now() + rem;
                        self.inner.sleep = Some(Box::pin(time::sleep_until(until)));
                    } else {
                        self.inner.read_wait = Some(cx.waker().clone());
                        return Poll::Pending;
                    }
                }
                Ok(()) => {
                    if buf.filled().len() == filled {
                        match ready!(self.inner.poll_action(cx)) {
                            Some(action) => {
                                self.inner.actions.push_back(action);
                                continue;
                            }
                            None => {
                                return Poll::Ready(Ok(()));
                            }
                        }
                    } else {
                        return Poll::Ready(Ok(()));
                    }
                }
                Err(e) => return Poll::Ready(Err(e)),
            }
        }
    }
}

impl AsyncWrite for Mock {
    fn poll_write(
        mut self: Pin<&mut Self>,
        cx: &mut task::Context<'_>,
        buf: &[u8],
    ) -> Poll<io::Result<usize>> {
        loop {
            if let Some(ref mut sleep) = self.inner.sleep {
                ready!(Pin::new(sleep).poll(cx));
            }

            // If a sleep is set, it has already fired
            self.inner.sleep = None;

            if self.inner.actions.is_empty() {
                match self.inner.poll_action(cx) {
                    Poll::Pending => {
                        // do not propagate pending
                    }
                    Poll::Ready(Some(action)) => {
                        self.inner.actions.push_back(action);
                    }
                    Poll::Ready(None) => {
                        panic!("unexpected write");
                    }
                }
            }

            match self.inner.write(buf) {
                Err(ref e) if e.kind() == io::ErrorKind::WouldBlock => {
                    if let Some(rem) = self.inner.remaining_wait() {
                        let until = Instant::now() + rem;
                        self.inner.sleep = Some(Box::pin(time::sleep_until(until)));
                    } else {
                        panic!("unexpected WouldBlock");
                    }
                }
                Ok(0) => {
                    // TODO: Is this correct?
                    if !self.inner.actions.is_empty() {
                        return Poll::Pending;
                    }

                    // TODO: Extract
                    match ready!(self.inner.poll_action(cx)) {
                        Some(action) => {
                            self.inner.actions.push_back(action);
                            continue;
                        }
                        None => {
                            panic!("unexpected write");
                        }
                    }
                }
                ret => {
                    self.maybe_wakeup_reader();
                    return Poll::Ready(ret);
                }
            }
        }
    }

    fn poll_flush(self: Pin<&mut Self>, _cx: &mut task::Context<'_>) -> Poll<io::Result<()>> {
        Poll::Ready(Ok(()))
    }

    fn poll_shutdown(self: Pin<&mut Self>, _cx: &mut task::Context<'_>) -> Poll<io::Result<()>> {
        Poll::Ready(Ok(()))
    }
}

/// Ensures that Mock isn't dropped with data "inside".
impl Drop for Mock {
    fn drop(&mut self) {
        // Avoid double panicking, since makes debugging much harder.
        if std::thread::panicking() {
            return;
        }

        self.inner.actions.iter().for_each(|a| match a {
            Action::Read(data) => assert!(data.is_empty(), "There is still data left to read."),
            Action::Write(data) => assert!(data.is_empty(), "There is still data left to write."),
            _ => (),
        });
    }
}
/*
/// Returns `true` if called from the context of a futures-rs Task
fn is_task_ctx() -> bool {
    use std::panic;

    // Save the existing panic hook
    let h = panic::take_hook();

    // Install a new one that does nothing
    panic::set_hook(Box::new(|_| {}));

    // Attempt to call the fn
    let r = panic::catch_unwind(|| task::current()).is_ok();

    // Re-install the old one
    panic::set_hook(h);

    // Return the result
    r
}
*/

impl fmt::Debug for Inner {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        write!(f, "Inner {{...}}")
    }
}

Coverage Report

Created: 2025-07-18 06:42

Line	Count	Source (jump to first uncovered line)
1		#![cfg(not(loom))]
2
3		//! A mock type implementing [`AsyncRead`] and [`AsyncWrite`].
4		//!
5		//!
6		//! # Overview
7		//!
8		//! Provides a type that implements [`AsyncRead`] + [`AsyncWrite`] that can be configured
9		//! to handle an arbitrary sequence of read and write operations. This is useful
10		//! for writing unit tests for networking services as using an actual network
11		//! type is fairly non deterministic.
12		//!
13		//! # Usage
14		//!
15		//! Attempting to write data that the mock isn't expecting will result in a
16		//! panic.
17		//!
18		//! [`AsyncRead`]: tokio::io::AsyncRead
19		//! [`AsyncWrite`]: tokio::io::AsyncWrite
20
21		use tokio::io::{AsyncRead, AsyncWrite, ReadBuf};
22		use tokio::sync::mpsc;
23		use tokio::time::{self, Duration, Instant, Sleep};
24		use tokio_stream::wrappers::UnboundedReceiverStream;
25
26		use futures_core::{ready, Stream};
27		use std::collections::VecDeque;
28		use std::fmt;
29		use std::future::Future;
30		use std::pin::Pin;
31		use std::sync::Arc;
32		use std::task::{self, Poll, Waker};
33		use std::{cmp, io};
34
35		/// An I/O object that follows a predefined script.
36		///
37		/// This value is created by `Builder` and implements `AsyncRead` + `AsyncWrite`. It
38		/// follows the scenario described by the builder and panics otherwise.
39		#[derive(Debug)]
40		pub struct Mock {
41		inner: Inner,
42		}
43
44		/// A handle to send additional actions to the related `Mock`.
45		#[derive(Debug)]
46		pub struct Handle {
47		tx: mpsc::UnboundedSender<Action>,
48		}
49
50		/// Builds `Mock` instances.
51		#[derive(Debug, Clone, Default)]
52		pub struct Builder {
53		// Sequence of actions for the Mock to take
54		actions: VecDeque<Action>,
55		}
56
57		#[derive(Debug, Clone)]
58		enum Action {
59		Read(Vec<u8>),
60		Write(Vec<u8>),
61		Wait(Duration),
62		// Wrapped in Arc so that Builder can be cloned and Send.
63		// Mock is not cloned as does not need to check Rc for ref counts.
64		ReadError(Option<Arc<io::Error>>),
65		WriteError(Option<Arc<io::Error>>),
66		}
67
68		struct Inner {
69		actions: VecDeque<Action>,
70		waiting: Option<Instant>,
71		sleep: Option<Pin<Box<Sleep>>>,
72		read_wait: Option<Waker>,
73		rx: UnboundedReceiverStream<Action>,
74		}
75
76		impl Builder {
77		/// Return a new, empty `Builder`.
78	0	pub fn new() -> Self {
79	0	Self::default()
80	0	}
81
82		/// Sequence a `read` operation.
83		///
84		/// The next operation in the mock's script will be to expect a `read` call
85		/// and return `buf`.
86	0	pub fn read(&mut self, buf: &[u8]) -> &mut Self {
87	0	self.actions.push_back(Action::Read(buf.into()));
88	0	self
89	0	}
90
91		/// Sequence a `read` operation that produces an error.
92		///
93		/// The next operation in the mock's script will be to expect a `read` call
94		/// and return `error`.
95	0	pub fn read_error(&mut self, error: io::Error) -> &mut Self {
96	0	let error = Some(error.into());
97	0	self.actions.push_back(Action::ReadError(error));
98	0	self
99	0	}
100
101		/// Sequence a `write` operation.
102		///
103		/// The next operation in the mock's script will be to expect a `write`
104		/// call.
105	0	pub fn write(&mut self, buf: &[u8]) -> &mut Self {
106	0	self.actions.push_back(Action::Write(buf.into()));
107	0	self
108	0	}
109
110		/// Sequence a `write` operation that produces an error.
111		///
112		/// The next operation in the mock's script will be to expect a `write`
113		/// call that provides `error`.
114	0	pub fn write_error(&mut self, error: io::Error) -> &mut Self {
115	0	let error = Some(error.into());
116	0	self.actions.push_back(Action::WriteError(error));
117	0	self
118	0	}
119
120		/// Sequence a wait.
121		///
122		/// The next operation in the mock's script will be to wait without doing so
123		/// for `duration` amount of time.
124	0	pub fn wait(&mut self, duration: Duration) -> &mut Self {
125	0	let duration = cmp::max(duration, Duration::from_millis(1));
126	0	self.actions.push_back(Action::Wait(duration));
127	0	self
128	0	}
129
130		/// Build a `Mock` value according to the defined script.
131	0	pub fn build(&mut self) -> Mock {
132	0	let (mock, _) = self.build_with_handle();
133	0	mock
134	0	}
135
136		/// Build a `Mock` value paired with a handle
137	0	pub fn build_with_handle(&mut self) -> (Mock, Handle) {
138	0	let (inner, handle) = Inner::new(self.actions.clone());
139	0
140	0	let mock = Mock { inner };
141	0
142	0	(mock, handle)
143	0	}
144		}
145
146		impl Handle {
147		/// Sequence a `read` operation.
148		///
149		/// The next operation in the mock's script will be to expect a `read` call
150		/// and return `buf`.
151	0	pub fn read(&mut self, buf: &[u8]) -> &mut Self {
152	0	self.tx.send(Action::Read(buf.into())).unwrap();
153	0	self
154	0	}
155
156		/// Sequence a `read` operation error.
157		///
158		/// The next operation in the mock's script will be to expect a `read` call
159		/// and return `error`.
160	0	pub fn read_error(&mut self, error: io::Error) -> &mut Self {
161	0	let error = Some(error.into());
162	0	self.tx.send(Action::ReadError(error)).unwrap();
163	0	self
164	0	}
165
166		/// Sequence a `write` operation.
167		///
168		/// The next operation in the mock's script will be to expect a `write`
169		/// call.
170	0	pub fn write(&mut self, buf: &[u8]) -> &mut Self {
171	0	self.tx.send(Action::Write(buf.into())).unwrap();
172	0	self
173	0	}
174
175		/// Sequence a `write` operation error.
176		///
177		/// The next operation in the mock's script will be to expect a `write`
178		/// call error.
179	0	pub fn write_error(&mut self, error: io::Error) -> &mut Self {
180	0	let error = Some(error.into());
181	0	self.tx.send(Action::WriteError(error)).unwrap();
182	0	self
183	0	}
184		}
185
186		impl Inner {
187	0	fn new(actions: VecDeque<Action>) -> (Inner, Handle) {
188	0	let (tx, rx) = mpsc::unbounded_channel();
189	0
190	0	let rx = UnboundedReceiverStream::new(rx);
191	0
192	0	let inner = Inner {
193	0	actions,
194	0	sleep: None,
195	0	read_wait: None,
196	0	rx,
197	0	waiting: None,
198	0	};
199	0
200	0	let handle = Handle { tx };
201	0
202	0	(inner, handle)
203	0	}
204
205	0	fn poll_action(&mut self, cx: &mut task::Context<'_>) -> Poll<Option<Action>> {
206	0	Pin::new(&mut self.rx).poll_next(cx)
207	0	}
208
209	0	fn read(&mut self, dst: &mut ReadBuf<'_>) -> io::Result<()> {
210	0	match self.action() {
211	0	Some(&mut Action::Read(ref mut data)) => {
212	0	// Figure out how much to copy
213	0	let n = cmp::min(dst.remaining(), data.len());
214	0
215	0	// Copy the data into the `dst` slice
216	0	dst.put_slice(&data[..n]);
217	0
218	0	// Drain the data from the source
219	0	data.drain(..n);
220	0
221	0	Ok(())
222		}
223	0	Some(&mut Action::ReadError(ref mut err)) => {
224	0	// As the
225	0	let err = err.take().expect("Should have been removed from actions.");
226	0	let err = Arc::try_unwrap(err).expect("There are no other references.");
227	0	Err(err)
228		}
229		Some(_) => {
230		// Either waiting or expecting a write
231	0	Err(io::ErrorKind::WouldBlock.into())
232		}
233	0	None => Ok(()),
234		}
235	0	}
236
237	0	fn write(&mut self, mut src: &[u8]) -> io::Result<usize> {
238	0	let mut ret = 0;
239	0
240	0	if self.actions.is_empty() {
241	0	return Err(io::ErrorKind::BrokenPipe.into());
242	0	}
243	0
244	0	if let Some(&mut Action::Wait(..)) = self.action() {
245	0	return Err(io::ErrorKind::WouldBlock.into());
246	0	}
247
248	0	if let Some(&mut Action::WriteError(ref mut err)) = self.action() {
249	0	let err = err.take().expect("Should have been removed from actions.");
250	0	let err = Arc::try_unwrap(err).expect("There are no other references.");
251	0	return Err(err);
252	0	}
253
254	0	for i in 0..self.actions.len() {
255	0	match self.actions[i] {
256	0	Action::Write(ref mut expect) => {
257	0	let n = cmp::min(src.len(), expect.len());
258	0
259	0	assert_eq!(&src[..n], &expect[..n]);
260
261		// Drop data that was matched
262	0	expect.drain(..n);
263	0	src = &src[n..];
264	0
265	0	ret += n;
266	0
267	0	if src.is_empty() {
268	0	return Ok(ret);
269	0	}
270		}
271		Action::Wait(..) \| Action::WriteError(..) => {
272	0	break;
273		}
274	0	_ => {}
275		}
276
277		// TODO: remove write
278		}
279
280	0	Ok(ret)
281	0	}
282
283	0	fn remaining_wait(&mut self) -> Option<Duration> {
284	0	match self.action() {
285	0	Some(&mut Action::Wait(dur)) => Some(dur),
286	0	_ => None,
287		}
288	0	}
289
290	0	fn action(&mut self) -> Option<&mut Action> {
291		loop {
292	0	if self.actions.is_empty() {
293	0	return None;
294	0	}
295	0
296	0	match self.actions[0] {
297	0	Action::Read(ref mut data) => {
298	0	if !data.is_empty() {
299	0	break;
300	0	}
301		}
302	0	Action::Write(ref mut data) => {
303	0	if !data.is_empty() {
304	0	break;
305	0	}
306		}
307	0	Action::Wait(ref mut dur) => {
308	0	if let Some(until) = self.waiting {
309	0	let now = Instant::now();
310	0
311	0	if now < until {
312	0	break;
313	0	} else {
314	0	self.waiting = None;
315	0	}
316		} else {
317	0	self.waiting = Some(Instant::now() + *dur);
318	0	break;
319		}
320		}
321	0	Action::ReadError(ref mut error) \| Action::WriteError(ref mut error) => {
322	0	if error.is_some() {
323	0	break;
324	0	}
325		}
326		}
327
328	0	let _action = self.actions.pop_front();
329		}
330
331	0	self.actions.front_mut()
332	0	}
333		}
334
335		// ===== impl Inner =====
336
337		impl Mock {
338	0	fn maybe_wakeup_reader(&mut self) {
339	0	match self.inner.action() {
340		Some(&mut Action::Read(_)) \| Some(&mut Action::ReadError(_)) \| None => {
341	0	if let Some(waker) = self.inner.read_wait.take() {
342	0	waker.wake();
343	0	}
344		}
345	0	_ => {}
346		}
347	0	}
348		}
349
350		impl AsyncRead for Mock {
351	0	fn poll_read(
352	0	mut self: Pin<&mut Self>,
353	0	cx: &mut task::Context<'_>,
354	0	buf: &mut ReadBuf<'_>,
355	0	) -> Poll<io::Result<()>> {
356		loop {
357	0	if let Some(ref mut sleep) = self.inner.sleep {
358	0	ready!(Pin::new(sleep).poll(cx));
359	0	}
360
361		// If a sleep is set, it has already fired
362	0	self.inner.sleep = None;
363	0
364	0	// Capture 'filled' to monitor if it changed
365	0	let filled = buf.filled().len();
366	0
367	0	match self.inner.read(buf) {
368	0	Err(ref e) if e.kind() == io::ErrorKind::WouldBlock => {
369	0	if let Some(rem) = self.inner.remaining_wait() {
370	0	let until = Instant::now() + rem;
371	0	self.inner.sleep = Some(Box::pin(time::sleep_until(until)));
372	0	} else {
373	0	self.inner.read_wait = Some(cx.waker().clone());
374	0	return Poll::Pending;
375		}
376		}
377		Ok(()) => {
378	0	if buf.filled().len() == filled {
379	0	match ready!(self.inner.poll_action(cx)) {
380	0	Some(action) => {
381	0	self.inner.actions.push_back(action);
382	0	continue;
383		}
384		None => {
385	0	return Poll::Ready(Ok(()));
386		}
387		}
388		} else {
389	0	return Poll::Ready(Ok(()));
390		}
391		}
392	0	Err(e) => return Poll::Ready(Err(e)),
393		}
394		}
395	0	}
396		}
397
398		impl AsyncWrite for Mock {
399	0	fn poll_write(
400	0	mut self: Pin<&mut Self>,
401	0	cx: &mut task::Context<'_>,
402	0	buf: &[u8],
403	0	) -> Poll<io::Result<usize>> {
404		loop {
405	0	if let Some(ref mut sleep) = self.inner.sleep {
406	0	ready!(Pin::new(sleep).poll(cx));
407	0	}
408
409		// If a sleep is set, it has already fired
410	0	self.inner.sleep = None;
411	0
412	0	if self.inner.actions.is_empty() {
413	0	match self.inner.poll_action(cx) {
414	0	Poll::Pending => {
415	0	// do not propagate pending
416	0	}
417	0	Poll::Ready(Some(action)) => {
418	0	self.inner.actions.push_back(action);
419	0	}
420		Poll::Ready(None) => {
421	0	panic!("unexpected write");
422		}
423		}
424	0	}
425
426	0	match self.inner.write(buf) {
427	0	Err(ref e) if e.kind() == io::ErrorKind::WouldBlock => {
428	0	if let Some(rem) = self.inner.remaining_wait() {
429	0	let until = Instant::now() + rem;
430	0	self.inner.sleep = Some(Box::pin(time::sleep_until(until)));
431	0	} else {
432	0	panic!("unexpected WouldBlock");
433		}
434		}
435		Ok(0) => {
436		// TODO: Is this correct?
437	0	if !self.inner.actions.is_empty() {
438	0	return Poll::Pending;
439	0	}
440
441		// TODO: Extract
442	0	match ready!(self.inner.poll_action(cx)) {
443	0	Some(action) => {
444	0	self.inner.actions.push_back(action);
445	0	continue;
446		}
447		None => {
448	0	panic!("unexpected write");
449		}
450		}
451		}
452	0	ret => {
453	0	self.maybe_wakeup_reader();
454	0	return Poll::Ready(ret);
455		}
456		}
457		}
458	0	}
459
460	0	fn poll_flush(self: Pin<&mut Self>, _cx: &mut task::Context<'_>) -> Poll<io::Result<()>> {
461	0	Poll::Ready(Ok(()))
462	0	}
463
464	0	fn poll_shutdown(self: Pin<&mut Self>, _cx: &mut task::Context<'_>) -> Poll<io::Result<()>> {
465	0	Poll::Ready(Ok(()))
466	0	}
467		}
468
469		/// Ensures that Mock isn't dropped with data "inside".
470		impl Drop for Mock {
471	0	fn drop(&mut self) {
472	0	// Avoid double panicking, since makes debugging much harder.
473	0	if std::thread::panicking() {
474	0	return;
475	0	}
476	0
477	0	self.inner.actions.iter().for_each(\|a\| match a {
478	0	Action::Read(data) => assert!(data.is_empty(), "There is still data left to read."),
479	0	Action::Write(data) => assert!(data.is_empty(), "There is still data left to write."),
480	0	_ => (),
481	0	});
482	0	}
483		}
484		/*
485		/// Returns `true` if called from the context of a futures-rs Task
486		fn is_task_ctx() -> bool {
487		use std::panic;
488
489		// Save the existing panic hook
490		let h = panic::take_hook();
491
492		// Install a new one that does nothing
493		panic::set_hook(Box::new(\|_\| {}));
494
495		// Attempt to call the fn
496		let r = panic::catch_unwind(\|\| task::current()).is_ok();
497
498		// Re-install the old one
499		panic::set_hook(h);
500
501		// Return the result
502		r
503		}
504		*/
505
506		impl fmt::Debug for Inner {
507	0	fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
508	0	write!(f, "Inner {{...}}")
509	0	}
510		}