ferray_core/
buffer.rs

1// ferray-core: AsRawBuffer trait for zero-copy interop (REQ-29)
2
3use crate::dimension::Dimension;
4use crate::dtype::{DType, Element};
5
6use crate::array::arc::ArcArray;
7use crate::array::owned::Array;
8use crate::array::view::ArrayView;
9
10/// Trait exposing the raw memory layout of an array for zero-copy interop.
11///
12/// Implementors provide enough information for foreign code (C, Python/NumPy,
13/// Arrow, etc.) to read the array data without copying.
14pub trait AsRawBuffer {
15    /// Raw pointer to the first element.
16    fn raw_ptr(&self) -> *const u8;
17
18    /// Shape as a slice of dimension sizes.
19    fn raw_shape(&self) -> &[usize];
20
21    /// Strides in bytes (not elements).
22    fn raw_strides_bytes(&self) -> Vec<isize>;
23
24    /// Runtime dtype descriptor.
25    fn raw_dtype(&self) -> DType;
26
27    /// Whether the data is C-contiguous.
28    fn is_c_contiguous(&self) -> bool;
29
30    /// Whether the data is Fortran-contiguous.
31    fn is_f_contiguous(&self) -> bool;
32}
33
34impl<T: Element, D: Dimension> AsRawBuffer for Array<T, D> {
35    fn raw_ptr(&self) -> *const u8 {
36        self.as_ptr() as *const u8
37    }
38
39    fn raw_shape(&self) -> &[usize] {
40        self.shape()
41    }
42
43    fn raw_strides_bytes(&self) -> Vec<isize> {
44        let itemsize = std::mem::size_of::<T>() as isize;
45        self.strides().iter().map(|&s| s * itemsize).collect()
46    }
47
48    fn raw_dtype(&self) -> DType {
49        T::dtype()
50    }
51
52    fn is_c_contiguous(&self) -> bool {
53        self.layout().is_c_contiguous()
54    }
55
56    fn is_f_contiguous(&self) -> bool {
57        self.layout().is_f_contiguous()
58    }
59}
60
61impl<T: Element, D: Dimension> AsRawBuffer for ArrayView<'_, T, D> {
62    fn raw_ptr(&self) -> *const u8 {
63        self.as_ptr() as *const u8
64    }
65
66    fn raw_shape(&self) -> &[usize] {
67        self.shape()
68    }
69
70    fn raw_strides_bytes(&self) -> Vec<isize> {
71        let itemsize = std::mem::size_of::<T>() as isize;
72        self.strides().iter().map(|&s| s * itemsize).collect()
73    }
74
75    fn raw_dtype(&self) -> DType {
76        T::dtype()
77    }
78
79    fn is_c_contiguous(&self) -> bool {
80        self.layout().is_c_contiguous()
81    }
82
83    fn is_f_contiguous(&self) -> bool {
84        self.layout().is_f_contiguous()
85    }
86}
87
88impl<T: Element, D: Dimension> AsRawBuffer for ArcArray<T, D> {
89    fn raw_ptr(&self) -> *const u8 {
90        self.as_ptr() as *const u8
91    }
92
93    fn raw_shape(&self) -> &[usize] {
94        self.shape()
95    }
96
97    fn raw_strides_bytes(&self) -> Vec<isize> {
98        let itemsize = std::mem::size_of::<T>() as isize;
99        self.strides().iter().map(|&s| s * itemsize).collect()
100    }
101
102    fn raw_dtype(&self) -> DType {
103        T::dtype()
104    }
105
106    fn is_c_contiguous(&self) -> bool {
107        self.layout().is_c_contiguous()
108    }
109
110    fn is_f_contiguous(&self) -> bool {
111        self.layout().is_f_contiguous()
112    }
113}
114
115#[cfg(test)]
116mod tests {
117    use super::*;
118    use crate::dimension::Ix2;
119
120    #[test]
121    fn raw_buffer_array() {
122        let arr = Array::<f64, Ix2>::from_vec(Ix2::new([2, 3]), vec![1.0, 2.0, 3.0, 4.0, 5.0, 6.0])
123            .unwrap();
124
125        assert_eq!(arr.raw_shape(), &[2, 3]);
126        assert_eq!(arr.raw_dtype(), DType::F64);
127        assert!(arr.is_c_contiguous());
128        assert!(!arr.raw_ptr().is_null());
129
130        // Strides in bytes: row stride = 3*8=24, col stride = 8
131        let strides = arr.raw_strides_bytes();
132        assert_eq!(strides, vec![24, 8]);
133    }
134
135    #[test]
136    fn raw_buffer_view() {
137        let arr = Array::<f32, Ix2>::from_vec(Ix2::new([2, 2]), vec![1.0, 2.0, 3.0, 4.0]).unwrap();
138        let v = arr.view();
139
140        assert_eq!(v.raw_dtype(), DType::F32);
141        assert_eq!(v.raw_shape(), &[2, 2]);
142        assert!(v.is_c_contiguous());
143    }
144
145    #[test]
146    fn raw_buffer_arc() {
147        let arr = Array::<i32, Ix2>::from_vec(Ix2::new([2, 2]), vec![1, 2, 3, 4]).unwrap();
148        let arc = ArcArray::from_owned(arr);
149
150        assert_eq!(arc.raw_dtype(), DType::I32);
151        assert_eq!(arc.raw_shape(), &[2, 2]);
152    }
153}
ferray_core/buffer.rs

ferray_core/
buffer.rs
