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

use std::{future::Future, pin::Pin, ptr};

use glib::{prelude::*, subclass::prelude::*, thread_guard::ThreadGuard, translate::*, Error};

use crate::{
    AsyncInitable, AsyncResult, Cancellable, CancellableFuture, GioFutureResult, LocalTask,
};

pub trait AsyncInitableImpl: ObjectImpl {
    fn init_future(
        &self,
        io_priority: glib::Priority,
    ) -> Pin<Box<dyn Future<Output = Result<(), Error>> + 'static>> {
        self.parent_init_future(io_priority)
    }
}

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

pub trait AsyncInitableImplExt: sealed::Sealed + AsyncInitableImpl + ObjectSubclass {
    fn parent_init_future(
        &self,
        io_priority: glib::Priority,
    ) -> Pin<Box<dyn Future<Output = Result<(), Error>> + 'static>> {
        unsafe {
            let type_data = Self::type_data();
            let parent_iface = type_data.as_ref().parent_interface::<AsyncInitable>()
                as *const ffi::GAsyncInitableIface;

            let init_async = (*parent_iface)
                .init_async
                .expect("no parent \"init_async\" implementation");

            unsafe extern "C" fn parent_init_future_callback<T>(
                source_object: *mut glib::gobject_ffi::GObject,
                res: *mut crate::ffi::GAsyncResult,
                user_data: glib::ffi::gpointer,
            ) where
                T: AsyncInitableImpl,
            {
                let type_data = T::type_data();
                let parent_iface = type_data.as_ref().parent_interface::<AsyncInitable>()
                    as *const ffi::GAsyncInitableIface;
                let init_finish = (*parent_iface)
                    .init_finish
                    .expect("no parent \"init_finish\" implementation");

                let r: Box<ThreadGuard<GioFutureResult<Result<(), Error>>>> =
                    Box::from_raw(user_data as *mut _);
                let r = r.into_inner();

                let mut error = ptr::null_mut();
                init_finish(source_object as *mut _, res, &mut error);
                let result = if error.is_null() {
                    Ok(())
                } else {
                    Err(from_glib_full(error))
                };
                r.resolve(result);
            }

            Box::pin(crate::GioFuture::new(
                &*self.obj(),
                move |obj, cancellable, res| {
                    let user_data: Box<ThreadGuard<GioFutureResult<Result<(), Error>>>> =
                        Box::new(ThreadGuard::new(res));
                    let user_data = Box::into_raw(user_data);
                    init_async(
                        obj.unsafe_cast_ref::<AsyncInitable>().to_glib_none().0,
                        io_priority.into_glib(),
                        cancellable.to_glib_none().0,
                        Some(parent_init_future_callback::<Self>),
                        user_data as *mut _,
                    );
                },
            ))
        }
    }
}

impl<T: AsyncInitableImpl> AsyncInitableImplExt for T {}

unsafe impl<T: AsyncInitableImpl> IsImplementable<T> for AsyncInitable {
    fn interface_init(iface: &mut glib::Interface<Self>) {
        let iface = iface.as_mut();
        iface.init_async = Some(async_initable_init_async::<T>);
        iface.init_finish = Some(async_initable_init_finish);
    }
}

unsafe extern "C" fn async_initable_init_async<T: AsyncInitableImpl>(
    initable: *mut ffi::GAsyncInitable,
    io_priority: std::os::raw::c_int,
    cancellable: *mut ffi::GCancellable,
    callback: ffi::GAsyncReadyCallback,
    user_data: glib::ffi::gpointer,
) {
    let instance = &*(initable as *mut T::Instance);
    let imp = instance.imp();
    let cancellable = Option::<Cancellable>::from_glib_none(cancellable);

    let task = callback.map(|callback| {
        let task = LocalTask::new(
            Some(imp.obj().unsafe_cast_ref::<glib::Object>()),
            cancellable.as_ref(),
            move |task, obj| {
                let result: *mut crate::ffi::GAsyncResult =
                    task.upcast_ref::<AsyncResult>().to_glib_none().0;
                let obj: *mut glib::gobject_ffi::GObject = obj.to_glib_none().0;
                callback(obj, result, user_data);
            },
        );
        task.set_check_cancellable(true);
        task.set_return_on_cancel(true);
        task
    });

    glib::MainContext::ref_thread_default().spawn_local(async move {
        let io_priority = from_glib(io_priority);
        let res = if let Some(cancellable) = cancellable {
            CancellableFuture::new(imp.init_future(io_priority), cancellable)
                .await
                .map_err(|cancelled| cancelled.into())
                .and_then(|res| res)
        } else {
            imp.init_future(io_priority).await
        };
        if let Some(task) = task {
            task.return_result(res.map(|_t| true));
        }
    });
}

unsafe extern "C" fn async_initable_init_finish(
    initable: *mut ffi::GAsyncInitable,
    res: *mut ffi::GAsyncResult,
    error: *mut *mut glib::ffi::GError,
) -> glib::ffi::gboolean {
    let res = from_glib_none::<_, AsyncResult>(res);

    let task = res
        .downcast::<LocalTask<bool>>()
        .expect("GAsyncResult is not a GTask");
    if !LocalTask::<bool>::is_valid(
        &task,
        Some(from_glib_borrow::<_, AsyncInitable>(initable).as_ref()),
    ) {
        panic!("Task is not valid for source object");
    }

    match task.propagate() {
        Ok(v) => {
            debug_assert!(v);
            true.into_glib()
        }
        Err(e) => {
            if !error.is_null() {
                *error = e.into_glib_ptr();
            }
            false.into_glib()
        }
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    use crate::prelude::*;

    pub mod imp {
        use std::cell::Cell;

        use super::*;

        pub struct AsyncInitableTestType(pub Cell<u64>);

        #[glib::object_subclass]
        impl ObjectSubclass for AsyncInitableTestType {
            const NAME: &'static str = "AsyncInitableTestType";
            type Type = super::AsyncInitableTestType;
            type Interfaces = (AsyncInitable,);

            fn new() -> Self {
                Self(Cell::new(0))
            }
        }

        impl AsyncInitableImpl for AsyncInitableTestType {
            fn init_future(
                &self,
                _io_priority: glib::Priority,
            ) -> Pin<Box<dyn Future<Output = Result<(), Error>> + 'static>> {
                let imp = glib::subclass::ObjectImplRef::new(self);
                Box::pin(async move {
                    glib::timeout_future_seconds(0).await;
                    imp.0.set(0x123456789abcdef);
                    Ok(())
                })
            }
        }

        impl ObjectImpl for AsyncInitableTestType {}
    }

    pub mod ffi {
        use super::*;
        pub type AsyncInitableTestType = <imp::AsyncInitableTestType as ObjectSubclass>::Instance;

        pub unsafe extern "C" fn async_initable_test_type_get_value(
            this: *mut AsyncInitableTestType,
        ) -> u64 {
            let this = super::AsyncInitableTestType::from_glib_borrow(this);
            this.imp().0.get()
        }
    }

    glib::wrapper! {
        pub struct AsyncInitableTestType(ObjectSubclass<imp::AsyncInitableTestType>)
            @implements AsyncInitable;
    }

    #[allow(clippy::new_without_default)]
    impl AsyncInitableTestType {
        pub async fn new() -> Self {
            AsyncInitable::new_future(glib::Priority::default())
                .await
                .expect("Failed creation/initialization of AsyncInitableTestType object")
        }

        pub unsafe fn new_uninit() -> Self {
            // This creates an uninitialized AsyncInitableTestType object, for testing
            // purposes. In real code, using AsyncInitable::new_future (like the new() method
            // does) is recommended.
            glib::Object::new_internal(Self::static_type(), &mut [])
                .downcast()
                .unwrap()
        }

        pub fn value(&self) -> u64 {
            self.imp().0.get()
        }
    }

    #[test]
    fn test_async_initable_with_init() {
        glib::MainContext::new().block_on(async {
            let res = unsafe {
                let test = AsyncInitableTestType::new_uninit();

                assert_ne!(0x123456789abcdef, test.value());

                test.init_future(glib::Priority::default())
                    .await
                    .map(|_| test)
            };
            assert!(res.is_ok());
            let test = res.unwrap();

            assert_eq!(0x123456789abcdef, test.value());
        });
    }

    #[test]
    fn test_async_initable_with_initable_new() {
        glib::MainContext::new().block_on(async {
            let test = AsyncInitableTestType::new().await;
            assert_eq!(0x123456789abcdef, test.value());
        });
    }

    #[test]
    #[should_panic = ""]
    fn test_async_initable_new_failure() {
        glib::MainContext::new().block_on(async {
            let value: u32 = 2;
            let _ = AsyncInitable::builder::<AsyncInitableTestType>()
                .property("invalid-property", value)
                .build_future(glib::Priority::default())
                .await;
            unreachable!();
        });
    }

    #[test]
    fn test_async_initable_with_initable_with_type() {
        glib::MainContext::new().block_on(async {
            let test = AsyncInitable::with_type_future(
                AsyncInitableTestType::static_type(),
                glib::Priority::default(),
            )
            .await
            .expect("Failed creation/initialization of AsyncInitableTestType object from type")
            .downcast::<AsyncInitableTestType>()
            .expect("Failed downcast of AsyncInitableTestType object");
            assert_eq!(0x123456789abcdef, test.value());
        });
    }

    #[test]
    fn test_async_initable_with_async_initable_with_values() {
        glib::MainContext::new().block_on(async {
            let test = AsyncInitable::with_type_future(
                AsyncInitableTestType::static_type(),
                glib::Priority::default(),
            )
            .await
            .expect("Failed creation/initialization of AsyncInitableTestType object from values")
            .downcast::<AsyncInitableTestType>()
            .expect("Failed downcast of AsyncInitableTestType object");
            assert_eq!(0x123456789abcdef, test.value());
        });
    }

    #[test]
    fn test_async_initable_through_ffi() {
        use futures_channel::oneshot;

        glib::MainContext::new().block_on(async {
            unsafe {
                let test = AsyncInitableTestType::new_uninit();
                let test: *mut ffi::AsyncInitableTestType = test.as_ptr();

                assert_ne!(
                    0x123456789abcdef,
                    ffi::async_initable_test_type_get_value(test)
                );

                let (tx, rx) = oneshot::channel::<Result<(), glib::Error>>();
                let user_data = Box::new(ThreadGuard::new(tx));
                unsafe extern "C" fn init_async_callback(
                    source_object: *mut glib::gobject_ffi::GObject,
                    res: *mut crate::ffi::GAsyncResult,
                    user_data: glib::ffi::gpointer,
                ) {
                    let tx: Box<ThreadGuard<oneshot::Sender<Result<(), glib::Error>>>> =
                        Box::from_raw(user_data as *mut _);
                    let tx = tx.into_inner();
                    let mut error = ptr::null_mut();
                    let ret = crate::ffi::g_async_initable_init_finish(
                        source_object as *mut _,
                        res,
                        &mut error,
                    );
                    assert_eq!(ret, glib::ffi::GTRUE);
                    let result = if error.is_null() {
                        Ok(())
                    } else {
                        Err(from_glib_full(error))
                    };
                    tx.send(result).unwrap();
                }

                crate::ffi::g_async_initable_init_async(
                    test as *mut crate::ffi::GAsyncInitable,
                    glib::ffi::G_PRIORITY_DEFAULT,
                    std::ptr::null_mut(),
                    Some(init_async_callback),
                    Box::into_raw(user_data) as *mut _,
                );

                let result = rx.await.unwrap();
                assert!(result.is_ok());
                assert_eq!(
                    0x123456789abcdef,
                    ffi::async_initable_test_type_get_value(test)
                );
            }
        });
    }
}