gio/
pollable_output_stream.rs

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

use std::{cell::RefCell, io, mem::transmute, pin::Pin};

use futures_channel::oneshot;
use futures_core::{
    stream::Stream,
    task::{Context, Poll},
    Future,
};
use futures_io::AsyncWrite;
use glib::{prelude::*, translate::*};

use crate::{error::to_std_io_result, ffi, prelude::*, Cancellable, PollableOutputStream};
#[cfg(feature = "v2_60")]
use crate::{OutputVector, PollableReturn};

mod sealed {
    pub trait Sealed {}
    impl<T: super::IsA<super::PollableOutputStream>> Sealed for T {}
}

pub trait PollableOutputStreamExtManual: sealed::Sealed + IsA<PollableOutputStream> {
    /// Creates a #GSource that triggers when @self can be written, or
    /// @cancellable is triggered or an error occurs. The callback on the
    /// source is of the #GPollableSourceFunc type.
    ///
    /// As with g_pollable_output_stream_is_writable(), it is possible that
    /// the stream may not actually be writable even after the source
    /// triggers, so you should use g_pollable_output_stream_write_nonblocking()
    /// rather than g_output_stream_write() from the callback.
    ///
    /// The behaviour of this method is undefined if
    /// g_pollable_output_stream_can_poll() returns [`false`] for @self.
    /// ## `cancellable`
    /// a #GCancellable, or [`None`]
    ///
    /// # Returns
    ///
    /// a new #GSource
    #[doc(alias = "g_pollable_output_stream_create_source")]
    fn create_source<F, C>(
        &self,
        cancellable: Option<&C>,
        name: Option<&str>,
        priority: glib::Priority,
        func: F,
    ) -> glib::Source
    where
        F: FnMut(&Self) -> glib::ControlFlow + 'static,
        C: IsA<Cancellable>,
    {
        unsafe extern "C" fn trampoline<
            O: IsA<PollableOutputStream>,
            F: FnMut(&O) -> glib::ControlFlow + 'static,
        >(
            stream: *mut ffi::GPollableOutputStream,
            func: glib::ffi::gpointer,
        ) -> glib::ffi::gboolean {
            let func: &RefCell<F> = &*(func as *const RefCell<F>);
            let mut func = func.borrow_mut();
            (*func)(PollableOutputStream::from_glib_borrow(stream).unsafe_cast_ref()).into_glib()
        }
        unsafe extern "C" fn destroy_closure<F>(ptr: glib::ffi::gpointer) {
            let _ = Box::<RefCell<F>>::from_raw(ptr as *mut _);
        }
        let cancellable = cancellable.map(|c| c.as_ref());
        let gcancellable = cancellable.to_glib_none();
        unsafe {
            let source = ffi::g_pollable_output_stream_create_source(
                self.as_ref().to_glib_none().0,
                gcancellable.0,
            );

            let trampoline = trampoline::<Self, F> as glib::ffi::gpointer;
            glib::ffi::g_source_set_callback(
                source,
                Some(transmute::<
                    glib::ffi::gpointer,
                    unsafe extern "C" fn(glib::ffi::gpointer) -> glib::ffi::gboolean,
                >(trampoline)),
                Box::into_raw(Box::new(RefCell::new(func))) as glib::ffi::gpointer,
                Some(destroy_closure::<F>),
            );
            glib::ffi::g_source_set_priority(source, priority.into_glib());

            if let Some(name) = name {
                glib::ffi::g_source_set_name(source, name.to_glib_none().0);
            }

            from_glib_full(source)
        }
    }

    fn create_source_future<C: IsA<Cancellable>>(
        &self,
        cancellable: Option<&C>,
        priority: glib::Priority,
    ) -> Pin<Box<dyn std::future::Future<Output = ()> + 'static>> {
        let cancellable: Option<Cancellable> = cancellable.map(|c| c.as_ref()).cloned();

        let obj = self.clone();
        Box::pin(glib::SourceFuture::new(move |send| {
            let mut send = Some(send);
            obj.create_source(cancellable.as_ref(), None, priority, move |_| {
                let _ = send.take().unwrap().send(());
                glib::ControlFlow::Break
            })
        }))
    }

    fn create_source_stream<C: IsA<Cancellable>>(
        &self,
        cancellable: Option<&C>,
        priority: glib::Priority,
    ) -> Pin<Box<dyn Stream<Item = ()> + 'static>> {
        let cancellable: Option<Cancellable> = cancellable.map(|c| c.as_ref()).cloned();

        let obj = self.clone();
        Box::pin(glib::SourceStream::new(move |send| {
            let send = Some(send);
            obj.create_source(cancellable.as_ref(), None, priority, move |_| {
                if send.as_ref().unwrap().unbounded_send(()).is_err() {
                    glib::ControlFlow::Break
                } else {
                    glib::ControlFlow::Continue
                }
            })
        }))
    }

    /// Attempts to write the bytes contained in the @n_vectors @vectors to @self,
    /// as with g_output_stream_writev(). If @self is not currently writable,
    /// this will immediately return %@G_POLLABLE_RETURN_WOULD_BLOCK, and you can
    /// use g_pollable_output_stream_create_source() to create a #GSource
    /// that will be triggered when @self is writable. @error will *not* be
    /// set in that case.
    ///
    /// Note that since this method never blocks, you cannot actually
    /// use @cancellable to cancel it. However, it will return an error
    /// if @cancellable has already been cancelled when you call, which
    /// may happen if you call this method after a source triggers due
    /// to having been cancelled.
    ///
    /// Also note that if [`PollableReturn::WouldBlock`][crate::PollableReturn::WouldBlock] is returned some underlying
    /// transports like D/TLS require that you re-send the same @vectors and
    /// @n_vectors in the next write call.
    ///
    /// The behaviour of this method is undefined if
    /// g_pollable_output_stream_can_poll() returns [`false`] for @self.
    /// ## `vectors`
    /// the buffer containing the #GOutputVectors to write.
    /// ## `cancellable`
    /// a #GCancellable, or [`None`]
    ///
    /// # Returns
    ///
    /// %@G_POLLABLE_RETURN_OK on success, [`PollableReturn::WouldBlock`][crate::PollableReturn::WouldBlock]
    /// if the stream is not currently writable (and @error is *not* set), or
    /// [`PollableReturn::Failed`][crate::PollableReturn::Failed] if there was an error in which case @error will
    /// be set.
    ///
    /// ## `bytes_written`
    /// location to store the number of bytes that were
    ///     written to the stream
    #[cfg(feature = "v2_60")]
    #[cfg_attr(docsrs, doc(cfg(feature = "v2_60")))]
    #[doc(alias = "g_pollable_output_stream_writev_nonblocking")]
    fn writev_nonblocking(
        &self,
        vectors: &[OutputVector],
        cancellable: Option<&impl IsA<Cancellable>>,
    ) -> Result<(PollableReturn, usize), glib::Error> {
        unsafe {
            let mut error = std::ptr::null_mut();
            let mut bytes_written = 0;

            let ret = ffi::g_pollable_output_stream_writev_nonblocking(
                self.as_ref().to_glib_none().0,
                vectors.as_ptr() as *const _,
                vectors.len(),
                &mut bytes_written,
                cancellable.map(|p| p.as_ref()).to_glib_none().0,
                &mut error,
            );
            if error.is_null() {
                Ok((from_glib(ret), bytes_written))
            } else {
                Err(from_glib_full(error))
            }
        }
    }

    fn into_async_write(self) -> Result<OutputStreamAsyncWrite<Self>, Self>
    where
        Self: IsA<PollableOutputStream>,
    {
        if self.can_poll() {
            Ok(OutputStreamAsyncWrite(self, None))
        } else {
            Err(self)
        }
    }
}

impl<O: IsA<PollableOutputStream>> PollableOutputStreamExtManual for O {}

#[derive(Debug)]
pub struct OutputStreamAsyncWrite<T: IsA<PollableOutputStream>>(
    T,
    Option<oneshot::Receiver<Result<(), glib::Error>>>,
);

impl<T: IsA<PollableOutputStream>> OutputStreamAsyncWrite<T> {
    pub fn into_output_stream(self) -> T {
        self.0
    }

    pub fn output_stream(&self) -> &T {
        &self.0
    }
}

impl<T: IsA<PollableOutputStream>> AsyncWrite for OutputStreamAsyncWrite<T> {
    fn poll_write(self: Pin<&mut Self>, cx: &mut Context, buf: &[u8]) -> Poll<io::Result<usize>> {
        let stream = Pin::get_ref(self.as_ref());
        let gio_result = stream
            .0
            .as_ref()
            .write_nonblocking(buf, crate::Cancellable::NONE);

        match gio_result {
            Ok(size) => Poll::Ready(Ok(size as usize)),
            Err(err) => {
                let kind = err
                    .kind::<crate::IOErrorEnum>()
                    .unwrap_or(crate::IOErrorEnum::Failed);
                if kind == crate::IOErrorEnum::WouldBlock {
                    let mut waker = Some(cx.waker().clone());
                    let source = stream.0.as_ref().create_source(
                        crate::Cancellable::NONE,
                        None,
                        glib::Priority::default(),
                        move |_| {
                            if let Some(waker) = waker.take() {
                                waker.wake();
                            }
                            glib::ControlFlow::Break
                        },
                    );
                    let main_context = glib::MainContext::ref_thread_default();
                    source.attach(Some(&main_context));

                    Poll::Pending
                } else {
                    Poll::Ready(Err(io::Error::new(io::ErrorKind::from(kind), err)))
                }
            }
        }
    }

    #[cfg(feature = "v2_60")]
    #[cfg_attr(docsrs, doc(cfg(feature = "v2_60")))]
    fn poll_write_vectored(
        self: Pin<&mut Self>,
        cx: &mut Context<'_>,
        bufs: &[io::IoSlice<'_>],
    ) -> Poll<io::Result<usize>> {
        let stream = Pin::get_ref(self.as_ref());
        let vectors = bufs
            .iter()
            .map(|v| OutputVector::new(v))
            .collect::<smallvec::SmallVec<[_; 2]>>();
        let gio_result = stream
            .0
            .as_ref()
            .writev_nonblocking(&vectors, crate::Cancellable::NONE);

        match gio_result {
            Ok((PollableReturn::Ok, size)) => Poll::Ready(Ok(size)),
            Ok((PollableReturn::WouldBlock, _)) => {
                let mut waker = Some(cx.waker().clone());
                let source = stream.0.as_ref().create_source(
                    crate::Cancellable::NONE,
                    None,
                    glib::Priority::default(),
                    move |_| {
                        if let Some(waker) = waker.take() {
                            waker.wake();
                        }
                        glib::ControlFlow::Break
                    },
                );
                let main_context = glib::MainContext::ref_thread_default();
                source.attach(Some(&main_context));

                Poll::Pending
            }
            Ok((_, _)) => unreachable!(),
            Err(err) => Poll::Ready(Err(io::Error::new(
                io::ErrorKind::from(
                    err.kind::<crate::IOErrorEnum>()
                        .unwrap_or(crate::IOErrorEnum::Failed),
                ),
                err,
            ))),
        }
    }

    fn poll_flush(self: Pin<&mut Self>, cx: &mut Context) -> Poll<io::Result<()>> {
        let stream = unsafe { Pin::get_unchecked_mut(self) };

        let rx = if let Some(ref mut rx) = stream.1 {
            rx
        } else {
            let (tx, rx) = oneshot::channel();
            stream.0.as_ref().flush_async(
                glib::Priority::default(),
                crate::Cancellable::NONE,
                move |res| {
                    let _ = tx.send(res);
                },
            );

            stream.1 = Some(rx);
            stream.1.as_mut().unwrap()
        };

        match Pin::new(rx).poll(cx) {
            Poll::Ready(Ok(res)) => {
                let _ = stream.1.take();
                Poll::Ready(to_std_io_result(res))
            }
            Poll::Ready(Err(_)) => {
                let _ = stream.1.take();
                Poll::Ready(Ok(()))
            }
            Poll::Pending => Poll::Pending,
        }
    }

    fn poll_close(self: Pin<&mut Self>, cx: &mut Context) -> Poll<io::Result<()>> {
        let stream = unsafe { Pin::get_unchecked_mut(self) };

        let rx = if let Some(ref mut rx) = stream.1 {
            rx
        } else {
            let (tx, rx) = oneshot::channel();
            stream.0.as_ref().close_async(
                glib::Priority::default(),
                crate::Cancellable::NONE,
                move |res| {
                    let _ = tx.send(res);
                },
            );

            stream.1 = Some(rx);
            stream.1.as_mut().unwrap()
        };

        match Pin::new(rx).poll(cx) {
            Poll::Ready(Ok(res)) => {
                let _ = stream.1.take();
                Poll::Ready(to_std_io_result(res))
            }
            Poll::Ready(Err(_)) => {
                let _ = stream.1.take();
                Poll::Ready(Ok(()))
            }
            Poll::Pending => Poll::Pending,
        }
    }
}