polars_arrow/array/list/
ffi.rs

1use polars_error::PolarsResult;
2
3use super::super::ffi::ToFfi;
4use super::super::Array;
5use super::ListArray;
6use crate::array::FromFfi;
7use crate::bitmap::align;
8use crate::ffi;
9use crate::offset::{Offset, OffsetsBuffer};
10
11unsafe impl<O: Offset> ToFfi for ListArray<O> {
12    fn buffers(&self) -> Vec<Option<*const u8>> {
13        vec![
14            self.validity.as_ref().map(|x| x.as_ptr()),
15            Some(self.offsets.buffer().storage_ptr().cast::<u8>()),
16        ]
17    }
18
19    fn children(&self) -> Vec<Box<dyn Array>> {
20        vec![self.values.clone()]
21    }
22
23    fn offset(&self) -> Option<usize> {
24        let offset = self.offsets.buffer().offset();
25        if let Some(bitmap) = self.validity.as_ref() {
26            if bitmap.offset() == offset {
27                Some(offset)
28            } else {
29                None
30            }
31        } else {
32            Some(offset)
33        }
34    }
35
36    fn to_ffi_aligned(&self) -> Self {
37        let offset = self.offsets.buffer().offset();
38
39        let validity = self.validity.as_ref().map(|bitmap| {
40            if bitmap.offset() == offset {
41                bitmap.clone()
42            } else {
43                align(bitmap, offset)
44            }
45        });
46
47        Self {
48            dtype: self.dtype.clone(),
49            validity,
50            offsets: self.offsets.clone(),
51            values: self.values.clone(),
52        }
53    }
54}
55
56impl<O: Offset, A: ffi::ArrowArrayRef> FromFfi<A> for ListArray<O> {
57    unsafe fn try_from_ffi(array: A) -> PolarsResult<Self> {
58        let dtype = array.dtype().clone();
59        let validity = unsafe { array.validity() }?;
60        let offsets = unsafe { array.buffer::<O>(1) }?;
61        let child = unsafe { array.child(0)? };
62        let values = ffi::try_from(child)?;
63
64        // assumption that data from FFI is well constructed
65        let offsets = unsafe { OffsetsBuffer::new_unchecked(offsets) };
66
67        Self::try_new(dtype, offsets, values, validity)
68    }
69}
polars_arrow/array/list/ffi.rs

polars_arrow/array/list/
ffi.rs
