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

use std::sync::Arc;

use polars_utils::slice::GetSaferUnchecked;

use super::{make_growable, Growable};
use crate::array::growable::utils::{extend_validity, prepare_validity};
use crate::array::{Array, StructArray};
use crate::bitmap::MutableBitmap;

/// Concrete [`Growable`] for the [`StructArray`].
pub struct GrowableStruct<'a> {
    arrays: Vec<&'a StructArray>,
    validity: Option<MutableBitmap>,
    values: Vec<Box<dyn Growable<'a> + 'a>>,
}

impl<'a> GrowableStruct<'a> {
    /// Creates a new [`GrowableStruct`] bound to `arrays` with a pre-allocated `capacity`.
    /// # Panics
    /// If `arrays` is empty.
    pub fn new(arrays: Vec<&'a StructArray>, mut use_validity: bool, capacity: usize) -> Self {
        assert!(!arrays.is_empty());

        // if any of the arrays has nulls, insertions from any array requires setting bits
        // as there is at least one array with nulls.
        if arrays.iter().any(|array| array.null_count() > 0) {
            use_validity = true;
        };

        let arrays = arrays
            .iter()
            .map(|array| array.as_any().downcast_ref::<StructArray>().unwrap())
            .collect::<Vec<_>>();

        // ([field1, field2], [field3, field4]) -> ([field1, field3], [field2, field3])
        let values = (0..arrays[0].values().len())
            .map(|i| {
                make_growable(
                    &arrays
                        .iter()
                        .map(|x| x.values()[i].as_ref())
                        .collect::<Vec<_>>(),
                    use_validity,
                    capacity,
                )
            })
            .collect::<Vec<Box<dyn Growable>>>();

        Self {
            arrays,
            values,
            validity: prepare_validity(use_validity, capacity),
        }
    }

    fn to(&mut self) -> StructArray {
        let validity = std::mem::take(&mut self.validity);
        let values = std::mem::take(&mut self.values);
        let values = values.into_iter().map(|mut x| x.as_box()).collect();

        StructArray::new(
            self.arrays[0].data_type().clone(),
            values,
            validity.map(|v| v.into()),
        )
    }
}

impl<'a> Growable<'a> for GrowableStruct<'a> {
    unsafe fn extend(&mut self, index: usize, start: usize, len: usize) {
        let array = *self.arrays.get_unchecked_release(index);
        extend_validity(&mut self.validity, array, start, len);

        if array.null_count() == 0 {
            self.values
                .iter_mut()
                .for_each(|child| child.extend(index, start, len))
        } else {
            (start..start + len).for_each(|i| {
                if array.is_valid(i) {
                    self.values
                        .iter_mut()
                        .for_each(|child| child.extend(index, i, 1))
                } else {
                    self.values
                        .iter_mut()
                        .for_each(|child| child.extend_validity(1))
                }
            })
        }
    }

    fn extend_validity(&mut self, additional: usize) {
        self.values
            .iter_mut()
            .for_each(|child| child.extend_validity(additional));
        if let Some(validity) = &mut self.validity {
            validity.extend_constant(additional, false);
        }
    }

    #[inline]
    fn len(&self) -> usize {
        if let Some(child) = self.values.first() {
            child.len()
        } else {
            unreachable!()
        }
    }

    fn as_arc(&mut self) -> Arc<dyn Array> {
        Arc::new(self.to())
    }

    fn as_box(&mut self) -> Box<dyn Array> {
        Box::new(self.to())
    }
}

impl<'a> From<GrowableStruct<'a>> for StructArray {
    fn from(val: GrowableStruct<'a>) -> Self {
        let values = val.values.into_iter().map(|mut x| x.as_box()).collect();

        StructArray::new(
            val.arrays[0].data_type().clone(),
            values,
            val.validity.map(|v| v.into()),
        )
    }
}