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
// Copyright 2014-2016 bluss and ndarray developers.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.

//! The data (inner representation) traits for ndarray

use rawpointer::PointerExt;
use std::mem::{self, size_of};
use std::ptr::NonNull;
use std::sync::Arc;

use crate::{
    ArrayBase, CowRepr, Dimension, OwnedArcRepr, OwnedRepr, RawViewRepr, ViewRepr,
};

/// Array representation trait.
///
/// For an array that meets the invariants of the `ArrayBase` type. This trait
/// does not imply any ownership or lifetime; pointers to elements in the array
/// may not be safe to dereference.
///
/// ***Note:*** `RawData` is not an extension interface at this point.
/// Traits in Rust can serve many different roles. This trait is public because
/// it is used as a bound on public methods.
pub unsafe trait RawData: Sized {
    /// The array element type.
    type Elem;

    #[doc(hidden)]
    // This method is only used for debugging
    fn _data_slice(&self) -> Option<&[Self::Elem]>;

    private_decl! {}
}

/// Array representation trait.
///
/// For an array with writable elements.
///
/// ***Internal trait, see `RawData`.***
pub unsafe trait RawDataMut: RawData {
    /// If possible, ensures that the array has unique access to its data.
    ///
    /// If `Self` provides safe mutable access to array elements, then it
    /// **must** panic or ensure that the data is unique.
    #[doc(hidden)]
    fn try_ensure_unique<D>(_: &mut ArrayBase<Self, D>)
    where
        Self: Sized,
        D: Dimension;

    /// If possible, returns whether the array has unique access to its data.
    ///
    /// If `Self` provides safe mutable access to array elements, then it
    /// **must** return `Some(_)`.
    #[doc(hidden)]
    fn try_is_unique(&mut self) -> Option<bool>;
}

/// Array representation trait.
///
/// An array representation that can be cloned.
///
/// ***Internal trait, see `RawData`.***
pub unsafe trait RawDataClone: RawData {
    #[doc(hidden)]
    /// Unsafe because, `ptr` must point inside the current storage.
    unsafe fn clone_with_ptr(&self, ptr: NonNull<Self::Elem>) -> (Self, NonNull<Self::Elem>);

    #[doc(hidden)]
    unsafe fn clone_from_with_ptr(
        &mut self,
        other: &Self,
        ptr: NonNull<Self::Elem>,
    ) -> NonNull<Self::Elem> {
        let (data, ptr) = other.clone_with_ptr(ptr);
        *self = data;
        ptr
    }
}

/// Array representation trait.
///
/// For an array with elements that can be accessed with safe code.
///
/// ***Internal trait, see `RawData`.***
pub unsafe trait Data: RawData {
    /// Converts the array to a uniquely owned array, cloning elements if necessary.
    #[doc(hidden)]
    fn into_owned<D>(self_: ArrayBase<Self, D>) -> ArrayBase<OwnedRepr<Self::Elem>, D>
    where
        Self::Elem: Clone,
        D: Dimension;
}

/// Array representation trait.
///
/// For an array with writable elements that can be accessed with safe code.
///
/// ***Internal trait, see `Data`.***
//
// # For implementers
//
// If you implement the `DataMut` trait, you are guaranteeing that the
// `RawDataMut::try_ensure_unique` implementation always panics or ensures that
// the data is unique. You are also guaranteeing that `try_is_unique` always
// returns `Some(_)`.
pub unsafe trait DataMut: Data + RawDataMut {
    /// Ensures that the array has unique access to its data.
    #[doc(hidden)]
    #[inline]
    fn ensure_unique<D>(self_: &mut ArrayBase<Self, D>)
    where
        Self: Sized,
        D: Dimension,
    {
        Self::try_ensure_unique(self_)
    }

    /// Returns whether the array has unique access to its data.
    #[doc(hidden)]
    #[inline]
    fn is_unique(&mut self) -> bool {
        self.try_is_unique().unwrap()
    }
}

/// Array representation trait.
///
/// An array representation that can be cloned and allows elements to be
/// accessed with safe code.
///
/// ***Internal trait, see `Data`.***
#[deprecated(note = "use `Data + RawDataClone` instead", since = "0.13.0")]
pub trait DataClone: Data + RawDataClone {}

#[allow(deprecated)]
impl<T> DataClone for T where T: Data + RawDataClone {}

unsafe impl<A> RawData for RawViewRepr<*const A> {
    type Elem = A;
    fn _data_slice(&self) -> Option<&[A]> {
        None
    }
    private_impl! {}
}

unsafe impl<A> RawDataClone for RawViewRepr<*const A> {
    unsafe fn clone_with_ptr(&self, ptr: NonNull<Self::Elem>) -> (Self, NonNull<Self::Elem>) {
        (*self, ptr)
    }
}

unsafe impl<A> RawData for RawViewRepr<*mut A> {
    type Elem = A;
    fn _data_slice(&self) -> Option<&[A]> {
        None
    }
    private_impl! {}
}

unsafe impl<A> RawDataMut for RawViewRepr<*mut A> {
    #[inline]
    fn try_ensure_unique<D>(_: &mut ArrayBase<Self, D>)
    where
        Self: Sized,
        D: Dimension,
    {
    }

    #[inline]
    fn try_is_unique(&mut self) -> Option<bool> {
        None
    }
}

unsafe impl<A> RawDataClone for RawViewRepr<*mut A> {
    unsafe fn clone_with_ptr(&self, ptr: NonNull<Self::Elem>) -> (Self, NonNull<Self::Elem>) {
        (*self, ptr)
    }
}

unsafe impl<A> RawData for OwnedArcRepr<A> {
    type Elem = A;
    fn _data_slice(&self) -> Option<&[A]> {
        Some(self.0.as_slice())
    }
    private_impl! {}
}

// NOTE: Copy on write
unsafe impl<A> RawDataMut for OwnedArcRepr<A>
where
    A: Clone,
{
    fn try_ensure_unique<D>(self_: &mut ArrayBase<Self, D>)
    where
        Self: Sized,
        D: Dimension,
    {
        if Arc::get_mut(&mut self_.data.0).is_some() {
            return;
        }
        if self_.dim.size() <= self_.data.0.len() / 2 {
            // Create a new vec if the current view is less than half of
            // backing data.
            unsafe {
                *self_ = ArrayBase::from_shape_vec_unchecked(
                    self_.dim.clone(),
                    self_.iter().cloned().collect(),
                );
            }
            return;
        }
        let rcvec = &mut self_.data.0;
        let a_size = mem::size_of::<A>() as isize;
        let our_off = if a_size != 0 {
            (self_.ptr.as_ptr() as isize - rcvec.as_ptr() as isize) / a_size
        } else {
            0
        };
        let rvec = Arc::make_mut(rcvec);
        unsafe {
            self_.ptr = rvec.as_nonnull_mut().offset(our_off);
        }
    }

    fn try_is_unique(&mut self) -> Option<bool> {
        Some(Arc::get_mut(&mut self.0).is_some())
    }
}

unsafe impl<A> Data for OwnedArcRepr<A> {
    fn into_owned<D>(mut self_: ArrayBase<Self, D>) -> ArrayBase<OwnedRepr<Self::Elem>, D>
    where
        A: Clone,
        D: Dimension,
    {
        Self::ensure_unique(&mut self_);
        let data = Arc::try_unwrap(self_.data.0).ok().unwrap();
        ArrayBase {
            data,
            ptr: self_.ptr,
            dim: self_.dim,
            strides: self_.strides,
        }
    }
}

unsafe impl<A> DataMut for OwnedArcRepr<A> where A: Clone {}

unsafe impl<A> RawDataClone for OwnedArcRepr<A> {
    unsafe fn clone_with_ptr(&self, ptr: NonNull<Self::Elem>) -> (Self, NonNull<Self::Elem>) {
        // pointer is preserved
        (self.clone(), ptr)
    }
}

unsafe impl<A> RawData for OwnedRepr<A> {
    type Elem = A;
    fn _data_slice(&self) -> Option<&[A]> {
        Some(self.as_slice())
    }
    private_impl! {}
}

unsafe impl<A> RawDataMut for OwnedRepr<A> {
    #[inline]
    fn try_ensure_unique<D>(_: &mut ArrayBase<Self, D>)
    where
        Self: Sized,
        D: Dimension,
    {
    }

    #[inline]
    fn try_is_unique(&mut self) -> Option<bool> {
        Some(true)
    }
}

unsafe impl<A> Data for OwnedRepr<A> {
    #[inline]
    fn into_owned<D>(self_: ArrayBase<Self, D>) -> ArrayBase<OwnedRepr<Self::Elem>, D>
    where
        A: Clone,
        D: Dimension,
    {
        self_
    }
}

unsafe impl<A> DataMut for OwnedRepr<A> {}

unsafe impl<A> RawDataClone for OwnedRepr<A>
where
    A: Clone,
{
    unsafe fn clone_with_ptr(&self, ptr: NonNull<Self::Elem>) -> (Self, NonNull<Self::Elem>) {
        let mut u = self.clone();
        let mut new_ptr = u.as_nonnull_mut();
        if size_of::<A>() != 0 {
            let our_off =
                (ptr.as_ptr() as isize - self.as_ptr() as isize) / mem::size_of::<A>() as isize;
            new_ptr = new_ptr.offset(our_off);
        }
        (u, new_ptr)
    }

    unsafe fn clone_from_with_ptr(
        &mut self,
        other: &Self,
        ptr: NonNull<Self::Elem>,
    ) -> NonNull<Self::Elem> {
        let our_off = if size_of::<A>() != 0 {
            (ptr.as_ptr() as isize - other.as_ptr() as isize) / mem::size_of::<A>() as isize
        } else {
            0
        };
        self.clone_from(&other);
        self.as_nonnull_mut().offset(our_off)
    }
}

unsafe impl<'a, A> RawData for ViewRepr<&'a A> {
    type Elem = A;
    fn _data_slice(&self) -> Option<&[A]> {
        None
    }
    private_impl! {}
}

unsafe impl<'a, A> Data for ViewRepr<&'a A> {
    fn into_owned<D>(self_: ArrayBase<Self, D>) -> ArrayBase<OwnedRepr<Self::Elem>, D>
    where
        Self::Elem: Clone,
        D: Dimension,
    {
        self_.to_owned()
    }
}

unsafe impl<'a, A> RawDataClone for ViewRepr<&'a A> {
    unsafe fn clone_with_ptr(&self, ptr: NonNull<Self::Elem>) -> (Self, NonNull<Self::Elem>) {
        (*self, ptr)
    }
}

unsafe impl<'a, A> RawData for ViewRepr<&'a mut A> {
    type Elem = A;
    fn _data_slice(&self) -> Option<&[A]> {
        None
    }
    private_impl! {}
}

unsafe impl<'a, A> RawDataMut for ViewRepr<&'a mut A> {
    #[inline]
    fn try_ensure_unique<D>(_: &mut ArrayBase<Self, D>)
    where
        Self: Sized,
        D: Dimension,
    {
    }

    #[inline]
    fn try_is_unique(&mut self) -> Option<bool> {
        Some(true)
    }
}

unsafe impl<'a, A> Data for ViewRepr<&'a mut A> {
    fn into_owned<D>(self_: ArrayBase<Self, D>) -> ArrayBase<OwnedRepr<Self::Elem>, D>
    where
        Self::Elem: Clone,
        D: Dimension,
    {
        self_.to_owned()
    }
}

unsafe impl<'a, A> DataMut for ViewRepr<&'a mut A> {}

/// Array representation trait.
///
/// A representation that is a unique or shared owner of its data.
///
/// ***Internal trait, see `Data`.***
pub unsafe trait DataOwned: Data {
    #[doc(hidden)]
    fn new(elements: Vec<Self::Elem>) -> Self;

    /// Converts the data representation to a shared (copy on write)
    /// representation, without any copying.
    #[doc(hidden)]
    fn into_shared(self) -> OwnedArcRepr<Self::Elem>;
}

/// Array representation trait.
///
/// A representation that is a lightweight view.
///
/// ***Internal trait, see `Data`.***
pub unsafe trait DataShared: Clone + Data + RawDataClone {}

unsafe impl<A> DataShared for OwnedArcRepr<A> {}
unsafe impl<'a, A> DataShared for ViewRepr<&'a A> {}

unsafe impl<A> DataOwned for OwnedRepr<A> {
    fn new(elements: Vec<A>) -> Self {
        OwnedRepr::from(elements)
    }
    fn into_shared(self) -> OwnedArcRepr<A> {
        OwnedArcRepr(Arc::new(self))
    }
}

unsafe impl<A> DataOwned for OwnedArcRepr<A> {
    fn new(elements: Vec<A>) -> Self {
        OwnedArcRepr(Arc::new(OwnedRepr::from(elements)))
    }

    fn into_shared(self) -> OwnedArcRepr<A> {
        self
    }
}

unsafe impl<'a, A> RawData for CowRepr<'a, A> {
    type Elem = A;
    fn _data_slice(&self) -> Option<&[A]> {
        match self {
            CowRepr::View(view) => view._data_slice(),
            CowRepr::Owned(data) => data._data_slice(),
        }
    }
    private_impl! {}
}

unsafe impl<'a, A> RawDataMut for CowRepr<'a, A>
where
    A: Clone,
{
    #[inline]
    fn try_ensure_unique<D>(array: &mut ArrayBase<Self, D>)
    where
        Self: Sized,
        D: Dimension,
    {
        match array.data {
            CowRepr::View(_) => {
                let owned = array.to_owned();
                array.data = CowRepr::Owned(owned.data);
                array.ptr = owned.ptr;
                array.dim = owned.dim;
                array.strides = owned.strides;
            }
            CowRepr::Owned(_) => {}
        }
    }

    #[inline]
    fn try_is_unique(&mut self) -> Option<bool> {
        Some(self.is_owned())
    }
}

unsafe impl<'a, A> RawDataClone for CowRepr<'a, A>
where
    A: Clone,
{
    unsafe fn clone_with_ptr(&self, ptr: NonNull<Self::Elem>) -> (Self, NonNull<Self::Elem>) {
        match self {
            CowRepr::View(view) => {
                let (new_view, ptr) = view.clone_with_ptr(ptr);
                (CowRepr::View(new_view), ptr)
            }
            CowRepr::Owned(data) => {
                let (new_data, ptr) = data.clone_with_ptr(ptr);
                (CowRepr::Owned(new_data), ptr)
            }
        }
    }

    #[doc(hidden)]
    unsafe fn clone_from_with_ptr(
        &mut self,
        other: &Self,
        ptr: NonNull<Self::Elem>,
    ) -> NonNull<Self::Elem> {
        match (&mut *self, other) {
            (CowRepr::View(self_), CowRepr::View(other)) => self_.clone_from_with_ptr(other, ptr),
            (CowRepr::Owned(self_), CowRepr::Owned(other)) => self_.clone_from_with_ptr(other, ptr),
            (_, CowRepr::Owned(other)) => {
                let (cloned, ptr) = other.clone_with_ptr(ptr);
                *self = CowRepr::Owned(cloned);
                ptr
            }
            (_, CowRepr::View(other)) => {
                let (cloned, ptr) = other.clone_with_ptr(ptr);
                *self = CowRepr::View(cloned);
                ptr
            }
        }
    }
}

unsafe impl<'a, A> Data for CowRepr<'a, A> {
    #[inline]
    fn into_owned<D>(self_: ArrayBase<CowRepr<'a, A>, D>) -> ArrayBase<OwnedRepr<Self::Elem>, D>
    where
        A: Clone,
        D: Dimension,
    {
        match self_.data {
            CowRepr::View(_) => self_.to_owned(),
            CowRepr::Owned(data) => ArrayBase {
                data,
                ptr: self_.ptr,
                dim: self_.dim,
                strides: self_.strides,
            },
        }
    }
}

unsafe impl<'a, A> DataMut for CowRepr<'a, A> where A: Clone {}

/// Array representation trait.
///
/// The RawDataSubst trait maps the element type of array storage, while
/// keeping the same kind of storage.
///
/// For example, `RawDataSubst<B>` can map the type `OwnedRepr<A>` to `OwnedRepr<B>`.
pub trait RawDataSubst<A>: RawData {
    /// The resulting array storage of the same kind but substituted element type
    type Output: RawData<Elem = A>;
}

impl<A, B> RawDataSubst<B> for OwnedRepr<A> {
    type Output = OwnedRepr<B>;
}

impl<A, B> RawDataSubst<B> for OwnedArcRepr<A> {
    type Output = OwnedArcRepr<B>;
}

impl<A, B> RawDataSubst<B> for RawViewRepr<*const A> {
    type Output = RawViewRepr<*const B>;
}

impl<A, B> RawDataSubst<B> for RawViewRepr<*mut A> {
    type Output = RawViewRepr<*mut B>;
}

impl<'a, A: 'a, B: 'a> RawDataSubst<B> for ViewRepr<&'a A> {
    type Output = ViewRepr<&'a B>;
}

impl<'a, A: 'a, B: 'a> RawDataSubst<B> for ViewRepr<&'a mut A> {
    type Output = ViewRepr<&'a mut B>;
}