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
// Take a look at the license at the top of the repository in the LICENSE file.

use futures_channel::{mpsc, oneshot};
use futures_core::future::{FusedFuture, Future};
use futures_core::stream::{FusedStream, Stream};
use futures_core::task;
use futures_core::task::Poll;
use std::marker::Unpin;
use std::pin;
use std::pin::Pin;
use std::time::Duration;

use crate::Continue;
use crate::MainContext;
use crate::Priority;
use crate::Source;

// rustdoc-stripper-ignore-next
/// Represents a `Future` around a `glib::Source`. The future will
/// be resolved once the source has provided a value
pub struct SourceFuture<F, T> {
    create_source: Option<F>,
    source: Option<(Source, oneshot::Receiver<T>)>,
}

impl<F, T: 'static> SourceFuture<F, T>
where
    F: FnOnce(oneshot::Sender<T>) -> Source + 'static,
{
    // rustdoc-stripper-ignore-next
    /// Create a new `SourceFuture`
    ///
    /// The provided closure should return a newly created `glib::Source` when called
    /// and pass the value provided by the source to the oneshot sender that is passed
    /// to the closure.
    pub fn new(create_source: F) -> SourceFuture<F, T> {
        SourceFuture {
            create_source: Some(create_source),
            source: None,
        }
    }
}

impl<F, T> Unpin for SourceFuture<F, T> {}

impl<F, T> Future for SourceFuture<F, T>
where
    F: FnOnce(oneshot::Sender<T>) -> Source + 'static,
{
    type Output = T;

    fn poll(mut self: pin::Pin<&mut Self>, ctx: &mut task::Context) -> Poll<T> {
        let SourceFuture {
            ref mut create_source,
            ref mut source,
            ..
        } = *self;

        if let Some(create_source) = create_source.take() {
            let main_context = MainContext::ref_thread_default();
            assert!(
                main_context.is_owner(),
                "Spawning futures only allowed if the thread is owning the MainContext"
            );

            // Channel for sending back the Source result to our future here.
            //
            // In theory, we could directly continue polling the
            // corresponding task from the Source callback,
            // however this would break at the very least
            // the g_main_current_source() API.
            let (send, recv) = oneshot::channel();

            let s = create_source(send);

            s.attach(Some(&main_context));
            *source = Some((s, recv));
        }

        // At this point we must have a receiver
        let res = {
            let &mut (_, ref mut receiver) = source.as_mut().unwrap();
            Pin::new(receiver).poll(ctx)
        };
        #[allow(clippy::match_wild_err_arm)]
        match res {
            Poll::Ready(Err(_)) => panic!("Source sender was unexpectedly closed"),
            Poll::Ready(Ok(v)) => {
                // Get rid of the reference to the source, it triggered
                let _ = source.take();
                Poll::Ready(v)
            }
            Poll::Pending => Poll::Pending,
        }
    }
}

impl<F, T> FusedFuture for SourceFuture<F, T>
where
    F: FnOnce(oneshot::Sender<T>) -> Source + 'static,
{
    fn is_terminated(&self) -> bool {
        self.create_source.is_none()
            && self
                .source
                .as_ref()
                .map_or(true, |(_, receiver)| receiver.is_terminated())
    }
}

impl<T, F> Drop for SourceFuture<T, F> {
    fn drop(&mut self) {
        // Get rid of the source, we don't care anymore if it still triggers
        if let Some((source, _)) = self.source.take() {
            source.destroy();
        }
    }
}

// rustdoc-stripper-ignore-next
/// Create a `Future` that will resolve after the given number of milliseconds.
///
/// The `Future` must be spawned on an `Executor` backed by a `glib::MainContext`.
pub fn timeout_future(value: Duration) -> Pin<Box<dyn Future<Output = ()> + Send + 'static>> {
    timeout_future_with_priority(crate::PRIORITY_DEFAULT, value)
}

// rustdoc-stripper-ignore-next
/// Create a `Future` that will resolve after the given number of milliseconds.
///
/// The `Future` must be spawned on an `Executor` backed by a `glib::MainContext`.
pub fn timeout_future_with_priority(
    priority: Priority,
    value: Duration,
) -> Pin<Box<dyn Future<Output = ()> + Send + 'static>> {
    Box::pin(SourceFuture::new(move |send| {
        let mut send = Some(send);
        crate::timeout_source_new(value, None, priority, move || {
            let _ = send.take().unwrap().send(());
            Continue(false)
        })
    }))
}

// rustdoc-stripper-ignore-next
/// Create a `Future` that will resolve after the given number of seconds.
///
/// The `Future` must be spawned on an `Executor` backed by a `glib::MainContext`.
pub fn timeout_future_seconds(value: u32) -> Pin<Box<dyn Future<Output = ()> + Send + 'static>> {
    timeout_future_seconds_with_priority(crate::PRIORITY_DEFAULT, value)
}

// rustdoc-stripper-ignore-next
/// Create a `Future` that will resolve after the given number of seconds.
///
/// The `Future` must be spawned on an `Executor` backed by a `glib::MainContext`.
pub fn timeout_future_seconds_with_priority(
    priority: Priority,
    value: u32,
) -> Pin<Box<dyn Future<Output = ()> + Send + 'static>> {
    Box::pin(SourceFuture::new(move |send| {
        let mut send = Some(send);
        crate::timeout_source_new_seconds(value, None, priority, move || {
            let _ = send.take().unwrap().send(());
            Continue(false)
        })
    }))
}

// rustdoc-stripper-ignore-next
/// Create a `Future` that will resolve once the child process with the given pid exits
///
/// The `Future` will resolve to the pid of the child process and the exit code.
///
/// The `Future` must be spawned on an `Executor` backed by a `glib::MainContext`.
pub fn child_watch_future(
    pid: crate::Pid,
) -> Pin<Box<dyn Future<Output = (crate::Pid, i32)> + Send + 'static>> {
    child_watch_future_with_priority(crate::PRIORITY_DEFAULT, pid)
}

// rustdoc-stripper-ignore-next
/// Create a `Future` that will resolve once the child process with the given pid exits
///
/// The `Future` will resolve to the pid of the child process and the exit code.
///
/// The `Future` must be spawned on an `Executor` backed by a `glib::MainContext`.
pub fn child_watch_future_with_priority(
    priority: Priority,
    pid: crate::Pid,
) -> Pin<Box<dyn Future<Output = (crate::Pid, i32)> + Send + 'static>> {
    Box::pin(SourceFuture::new(move |send| {
        let mut send = Some(send);
        crate::child_watch_source_new(pid, None, priority, move |pid, code| {
            let _ = send.take().unwrap().send((pid, code));
        })
    }))
}

#[cfg(any(unix, feature = "dox"))]
#[cfg_attr(feature = "dox", doc(cfg(unix)))]
// rustdoc-stripper-ignore-next
/// Create a `Future` that will resolve once the given UNIX signal is raised
///
/// The `Future` must be spawned on an `Executor` backed by a `glib::MainContext`.
pub fn unix_signal_future(signum: i32) -> Pin<Box<dyn Future<Output = ()> + Send + 'static>> {
    unix_signal_future_with_priority(crate::PRIORITY_DEFAULT, signum)
}

#[cfg(any(unix, feature = "dox"))]
#[cfg_attr(feature = "dox", doc(cfg(unix)))]
// rustdoc-stripper-ignore-next
/// Create a `Future` that will resolve once the given UNIX signal is raised
///
/// The `Future` must be spawned on an `Executor` backed by a `glib::MainContext`.
pub fn unix_signal_future_with_priority(
    priority: Priority,
    signum: i32,
) -> Pin<Box<dyn Future<Output = ()> + Send + 'static>> {
    Box::pin(SourceFuture::new(move |send| {
        let mut send = Some(send);
        crate::unix_signal_source_new(signum, None, priority, move || {
            let _ = send.take().unwrap().send(());
            Continue(false)
        })
    }))
}

// rustdoc-stripper-ignore-next
/// Represents a `Stream` around a `glib::Source`. The stream will
/// be provide all values that are provided by the source
pub struct SourceStream<F, T> {
    create_source: Option<F>,
    source: Option<(Source, mpsc::UnboundedReceiver<T>)>,
}

impl<F, T> Unpin for SourceStream<F, T> {}

impl<F, T: 'static> SourceStream<F, T>
where
    F: FnOnce(mpsc::UnboundedSender<T>) -> Source + 'static,
{
    // rustdoc-stripper-ignore-next
    /// Create a new `SourceStream`
    ///
    /// The provided closure should return a newly created `glib::Source` when called
    /// and pass the values provided by the source to the sender that is passed
    /// to the closure.
    pub fn new(create_source: F) -> SourceStream<F, T> {
        SourceStream {
            create_source: Some(create_source),
            source: None,
        }
    }
}

impl<F, T> Stream for SourceStream<F, T>
where
    F: FnOnce(mpsc::UnboundedSender<T>) -> Source + 'static,
{
    type Item = T;

    fn poll_next(mut self: pin::Pin<&mut Self>, ctx: &mut task::Context) -> Poll<Option<T>> {
        let SourceStream {
            ref mut create_source,
            ref mut source,
            ..
        } = *self;

        if let Some(create_source) = create_source.take() {
            let main_context = MainContext::ref_thread_default();
            assert!(
                main_context.is_owner(),
                "Spawning futures only allowed if the thread is owning the MainContext"
            );

            // Channel for sending back the Source result to our future here.
            //
            // In theory we could directly continue polling the
            // corresponding task from the Source callback,
            // however this would break at the very least
            // the g_main_current_source() API.
            let (send, recv) = mpsc::unbounded();

            let s = create_source(send);

            s.attach(Some(&main_context));
            *source = Some((s, recv));
        }

        // At this point we must have a receiver
        let res = {
            let &mut (_, ref mut receiver) = source.as_mut().unwrap();
            Pin::new(receiver).poll_next(ctx)
        };
        #[allow(clippy::match_wild_err_arm)]
        match res {
            Poll::Ready(v) => {
                if v.is_none() {
                    // Get rid of the reference to the source, it triggered
                    let _ = source.take();
                }
                Poll::Ready(v)
            }
            Poll::Pending => Poll::Pending,
        }
    }
}

impl<F, T> FusedStream for SourceStream<F, T>
where
    F: FnOnce(mpsc::UnboundedSender<T>) -> Source + 'static,
{
    fn is_terminated(&self) -> bool {
        self.create_source.is_none()
            && self
                .source
                .as_ref()
                .map_or(true, |(_, receiver)| receiver.is_terminated())
    }
}

impl<T, F> Drop for SourceStream<T, F> {
    fn drop(&mut self) {
        // Get rid of the source, we don't care anymore if it still triggers
        if let Some((source, _)) = self.source.take() {
            source.destroy();
        }
    }
}

// rustdoc-stripper-ignore-next
/// Create a `Stream` that will provide a value every given number of milliseconds.
///
/// The `Future` must be spawned on an `Executor` backed by a `glib::MainContext`.
pub fn interval_stream(value: Duration) -> Pin<Box<dyn Stream<Item = ()> + Send + 'static>> {
    interval_stream_with_priority(crate::PRIORITY_DEFAULT, value)
}

// rustdoc-stripper-ignore-next
/// Create a `Stream` that will provide a value every given number of milliseconds.
///
/// The `Future` must be spawned on an `Executor` backed by a `glib::MainContext`.
pub fn interval_stream_with_priority(
    priority: Priority,
    value: Duration,
) -> Pin<Box<dyn Stream<Item = ()> + Send + 'static>> {
    Box::pin(SourceStream::new(move |send| {
        crate::timeout_source_new(value, None, priority, move || {
            if send.unbounded_send(()).is_err() {
                Continue(false)
            } else {
                Continue(true)
            }
        })
    }))
}

// rustdoc-stripper-ignore-next
/// Create a `Stream` that will provide a value every given number of seconds.
///
/// The `Stream` must be spawned on an `Executor` backed by a `glib::MainContext`.
pub fn interval_stream_seconds(value: u32) -> Pin<Box<dyn Stream<Item = ()> + Send + 'static>> {
    interval_stream_seconds_with_priority(crate::PRIORITY_DEFAULT, value)
}

// rustdoc-stripper-ignore-next
/// Create a `Stream` that will provide a value every given number of seconds.
///
/// The `Stream` must be spawned on an `Executor` backed by a `glib::MainContext`.
pub fn interval_stream_seconds_with_priority(
    priority: Priority,
    value: u32,
) -> Pin<Box<dyn Stream<Item = ()> + Send + 'static>> {
    Box::pin(SourceStream::new(move |send| {
        crate::timeout_source_new_seconds(value, None, priority, move || {
            if send.unbounded_send(()).is_err() {
                Continue(false)
            } else {
                Continue(true)
            }
        })
    }))
}

#[cfg(any(unix, feature = "dox"))]
#[cfg_attr(feature = "dox", doc(cfg(unix)))]
// rustdoc-stripper-ignore-next
/// Create a `Stream` that will provide a value whenever the given UNIX signal is raised
///
/// The `Stream` must be spawned on an `Executor` backed by a `glib::MainContext`.
pub fn unix_signal_stream(signum: i32) -> Pin<Box<dyn Stream<Item = ()> + Send + 'static>> {
    unix_signal_stream_with_priority(crate::PRIORITY_DEFAULT, signum)
}

#[cfg(any(unix, feature = "dox"))]
#[cfg_attr(feature = "dox", doc(cfg(unix)))]
// rustdoc-stripper-ignore-next
/// Create a `Stream` that will provide a value whenever the given UNIX signal is raised
///
/// The `Stream` must be spawned on an `Executor` backed by a `glib::MainContext`.
pub fn unix_signal_stream_with_priority(
    priority: Priority,
    signum: i32,
) -> Pin<Box<dyn Stream<Item = ()> + Send + 'static>> {
    Box::pin(SourceStream::new(move |send| {
        crate::unix_signal_source_new(signum, None, priority, move || {
            if send.unbounded_send(()).is_err() {
                Continue(false)
            } else {
                Continue(true)
            }
        })
    }))
}

#[cfg(test)]
mod tests {
    use super::*;
    use futures_util::future::FutureExt;
    use futures_util::stream::StreamExt;
    use std::thread;
    use std::time::Duration;

    #[test]
    fn test_timeout() {
        let c = MainContext::new();

        c.block_on(timeout_future(Duration::from_millis(20)));
    }

    #[test]
    fn test_timeout_send() {
        let c = MainContext::new();
        let l = crate::MainLoop::new(Some(&c), false);

        let l_clone = l.clone();
        c.spawn(timeout_future(Duration::from_millis(20)).then(move |()| {
            l_clone.quit();
            futures_util::future::ready(())
        }));

        l.run();
    }

    #[test]
    fn test_interval() {
        let c = MainContext::new();

        let mut count = 0;

        {
            let count = &mut count;
            c.block_on(
                interval_stream(Duration::from_millis(20))
                    .take(2)
                    .for_each(|()| {
                        *count += 1;

                        futures_util::future::ready(())
                    })
                    .map(|_| ()),
            );
        }

        assert_eq!(count, 2);
    }

    #[test]
    fn test_timeout_and_channel() {
        let c = MainContext::default();

        let res = c.block_on(timeout_future(Duration::from_millis(20)).then(|()| {
            let (sender, receiver) = oneshot::channel();

            thread::spawn(move || {
                sender.send(1).unwrap();
            });

            receiver.then(|i| futures_util::future::ready(i.unwrap()))
        }));

        assert_eq!(res, 1);
    }
}