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

use crate::prelude::*;
use arrow::array::Array;
use arrow::buffer::Buffer;

impl<T> ToBitRepr for ChunkedArray<T>
where
    T: PolarsNumericType,
{
    fn bit_repr_is_large() -> bool {
        std::mem::size_of::<T::Native>() == 8
    }

    fn bit_repr_large(&self) -> UInt64Chunked {
        if std::mem::size_of::<T::Native>() == 8 {
            let chunks = self
                .downcast_iter()
                .map(|array| {
                    let buf = array.values().clone();
                    // Safety:
                    // we just check the size of T::Native to be 64 bits
                    // The fields can still be reordered between generic types
                    // so we do some extra assertions
                    let len = buf.len();
                    let offset = buf.offset();
                    let ptr = buf.as_slice().as_ptr() as usize;
                    #[allow(clippy::transmute_undefined_repr)]
                    let reinterpretted_buf = unsafe { std::mem::transmute::<_, Buffer<u64>>(buf) };
                    assert_eq!(reinterpretted_buf.len(), len);
                    assert_eq!(reinterpretted_buf.offset(), offset);
                    assert_eq!(reinterpretted_buf.as_slice().as_ptr() as usize, ptr);
                    Arc::new(PrimitiveArray::from_data(
                        ArrowDataType::UInt64,
                        reinterpretted_buf,
                        array.validity().cloned(),
                    )) as Arc<dyn Array>
                })
                .collect::<Vec<_>>();
            UInt64Chunked::from_chunks(self.name(), chunks)
        } else {
            unreachable!()
        }
    }

    fn bit_repr_small(&self) -> UInt32Chunked {
        if std::mem::size_of::<T::Native>() == 4 {
            let chunks = self
                .downcast_iter()
                .map(|array| {
                    let buf = array.values().clone();
                    // Safety:
                    // we just check the size of T::Native to be 32 bits
                    // The fields can still be reordered between generic types
                    // so we do some extra assertions
                    let len = buf.len();
                    let offset = buf.offset();
                    let ptr = buf.as_slice().as_ptr() as usize;
                    #[allow(clippy::transmute_undefined_repr)]
                    let reinterpretted_buf = unsafe { std::mem::transmute::<_, Buffer<u32>>(buf) };
                    assert_eq!(reinterpretted_buf.len(), len);
                    assert_eq!(reinterpretted_buf.offset(), offset);
                    assert_eq!(reinterpretted_buf.as_slice().as_ptr() as usize, ptr);
                    Arc::new(PrimitiveArray::from_data(
                        ArrowDataType::UInt32,
                        reinterpretted_buf,
                        array.validity().cloned(),
                    )) as Arc<dyn Array>
                })
                .collect::<Vec<_>>();
            UInt32Chunked::from_chunks(self.name(), chunks)
        } else {
            self.cast(&DataType::UInt32).unwrap().u32().unwrap().clone()
        }
    }
}

#[cfg(feature = "reinterpret")]
impl Reinterpret for UInt64Chunked {
    fn reinterpret_signed(&self) -> Series {
        let chunks = self
            .downcast_iter()
            .map(|array| {
                let buf = array.values().clone();
                // Safety
                // same bit length u64 <-> i64
                // The fields can still be reordered between generic types
                // so we do some extra assertions
                let len = buf.len();
                let offset = buf.offset();
                let ptr = buf.as_slice().as_ptr() as usize;
                #[allow(clippy::transmute_undefined_repr)]
                let reinterpretted_buf = unsafe { std::mem::transmute::<_, Buffer<i64>>(buf) };
                assert_eq!(reinterpretted_buf.len(), len);
                assert_eq!(reinterpretted_buf.offset(), offset);
                assert_eq!(reinterpretted_buf.as_slice().as_ptr() as usize, ptr);
                Arc::new(PrimitiveArray::from_data(
                    ArrowDataType::Int64,
                    reinterpretted_buf,
                    array.validity().cloned(),
                )) as Arc<dyn Array>
            })
            .collect::<Vec<_>>();
        Int64Chunked::from_chunks(self.name(), chunks).into_series()
    }

    fn reinterpret_unsigned(&self) -> Series {
        self.clone().into_series()
    }
}
#[cfg(feature = "reinterpret")]
impl Reinterpret for Int64Chunked {
    fn reinterpret_signed(&self) -> Series {
        self.clone().into_series()
    }

    fn reinterpret_unsigned(&self) -> Series {
        self.bit_repr_large().into_series()
    }
}

impl UInt64Chunked {
    pub(crate) fn reinterpret_float(&self) -> Series {
        let chunks = self
            .downcast_iter()
            .map(|array| {
                let buf = array.values().clone();
                // Safety
                // same bit length u64 <-> f64
                // The fields can still be reordered between generic types
                // so we do some extra assertions
                let len = buf.len();
                let offset = buf.offset();
                let ptr = buf.as_slice().as_ptr() as usize;
                #[allow(clippy::transmute_undefined_repr)]
                let reinterpretted_buf = unsafe { std::mem::transmute::<_, Buffer<f64>>(buf) };
                assert_eq!(reinterpretted_buf.len(), len);
                assert_eq!(reinterpretted_buf.offset(), offset);
                assert_eq!(reinterpretted_buf.as_slice().as_ptr() as usize, ptr);
                Arc::new(PrimitiveArray::from_data(
                    ArrowDataType::Float64,
                    reinterpretted_buf,
                    array.validity().cloned(),
                )) as Arc<dyn Array>
            })
            .collect::<Vec<_>>();
        Float64Chunked::from_chunks(self.name(), chunks).into()
    }
}
impl UInt32Chunked {
    pub(crate) fn reinterpret_float(&self) -> Series {
        let chunks = self
            .downcast_iter()
            .map(|array| {
                let buf = array.values().clone();
                // Safety
                // same bit length u32 <-> f32
                // The fields can still be reordered between generic types
                // so we do some extra assertions
                let len = buf.len();
                let offset = buf.offset();
                let ptr = buf.as_slice().as_ptr() as usize;
                #[allow(clippy::transmute_undefined_repr)]
                let reinterpretted_buf = unsafe { std::mem::transmute::<_, Buffer<f32>>(buf) };
                assert_eq!(reinterpretted_buf.len(), len);
                assert_eq!(reinterpretted_buf.offset(), offset);
                assert_eq!(reinterpretted_buf.as_slice().as_ptr() as usize, ptr);
                Arc::new(PrimitiveArray::from_data(
                    ArrowDataType::Float32,
                    reinterpretted_buf,
                    array.validity().cloned(),
                )) as Arc<dyn Array>
            })
            .collect::<Vec<_>>();
        Float32Chunked::from_chunks(self.name(), chunks).into()
    }
}

/// Used to save compilation paths. Use carefully. Although this is safe,
/// if misused it can lead to incorrect results.
impl Float32Chunked {
    pub(crate) fn apply_as_ints<F>(&self, f: F) -> Series
    where
        F: Fn(&Series) -> Series,
    {
        let s = self.bit_repr_small().into_series();
        let out = f(&s);
        let out = out.u32().unwrap();
        out.reinterpret_float()
    }
}
impl Float64Chunked {
    pub(crate) fn apply_as_ints<F>(&self, f: F) -> Series
    where
        F: Fn(&Series) -> Series,
    {
        let s = self.bit_repr_large().into_series();
        let out = f(&s);
        let out = out.u64().unwrap();
        out.reinterpret_float()
    }
}