polars_core/chunked_array/object/extension/
drop.rs

1use crate::chunked_array::object::extension::PolarsExtension;
2use crate::prelude::*;
3
4/// This will dereference a raw ptr when dropping the [`PolarsExtension`], make sure that it's valid.
5pub(crate) unsafe fn drop_list(ca: &ListChunked) {
6    let mut inner = ca.inner_dtype();
7    let mut nested_count = 0;
8
9    while let Some(a) = inner.inner_dtype() {
10        nested_count += 1;
11        inner = a;
12    }
13
14    if matches!(inner, DataType::Object(_)) {
15        if nested_count != 0 {
16            panic!("multiple nested objects not yet supported")
17        }
18        // if empty the memory is leaked somewhere
19        assert!(!ca.chunks.is_empty());
20        for lst_arr in &ca.chunks {
21            if let ArrowDataType::LargeList(fld) = lst_arr.dtype() {
22                let dtype = fld.dtype();
23
24                assert!(matches!(dtype, ArrowDataType::Extension(_)));
25
26                // recreate the polars extension so that the content is dropped
27                let arr = lst_arr.as_any().downcast_ref::<LargeListArray>().unwrap();
28
29                let values = arr.values();
30                drop_object_array(values.as_ref())
31            }
32        }
33    }
34}
35
36pub(crate) unsafe fn drop_object_array(values: &dyn Array) {
37    let arr = values
38        .as_any()
39        .downcast_ref::<FixedSizeBinaryArray>()
40        .unwrap();
41
42    // If the buf is not shared with anyone but us we can deallocate.
43    let buf = arr.values();
44    if buf.storage_refcount() == 1 && !buf.is_empty() {
45        PolarsExtension::new(arr.clone());
46    };
47}