arrow_array/array/
fixed_size_list_array.rs

1// Licensed to the Apache Software Foundation (ASF) under one
2// or more contributor license agreements.  See the NOTICE file
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4// regarding copyright ownership.  The ASF licenses this file
5// to you under the Apache License, Version 2.0 (the
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8//
9//   http://www.apache.org/licenses/LICENSE-2.0
10//
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14// KIND, either express or implied.  See the License for the
15// specific language governing permissions and limitations
16// under the License.
17
18use crate::array::print_long_array;
19use crate::builder::{FixedSizeListBuilder, PrimitiveBuilder};
20use crate::iterator::FixedSizeListIter;
21use crate::{Array, ArrayAccessor, ArrayRef, ArrowPrimitiveType, make_array};
22use arrow_buffer::ArrowNativeType;
23use arrow_buffer::buffer::NullBuffer;
24use arrow_data::{ArrayData, ArrayDataBuilder};
25use arrow_schema::{ArrowError, DataType, FieldRef};
26use std::any::Any;
27use std::sync::Arc;
28
29/// An array of [fixed length lists], similar to JSON arrays
30/// (e.g. `["A", "B"]`).
31///
32/// Lists are represented using a `values` child
33/// array where each list has a fixed size of `value_length`.
34///
35/// Use [`FixedSizeListBuilder`] to construct a [`FixedSizeListArray`].
36///
37/// # Representation
38///
39/// A [`FixedSizeListArray`] can represent a list of values of any other
40/// supported Arrow type. Each element of the `FixedSizeListArray` itself is
41/// a list which may contain NULL and non-null values,
42/// or may itself be NULL.
43///
44/// For example, this `FixedSizeListArray` stores lists of strings:
45///
46/// ```text
47/// ┌─────────────┐
48/// │    [A,B]    │
49/// ├─────────────┤
50/// │    NULL     │
51/// ├─────────────┤
52/// │   [C,NULL]  │
53/// └─────────────┘
54/// ```
55///
56/// The `values` of this `FixedSizeListArray`s are stored in a child
57/// [`StringArray`] where logical null values take up `values_length` slots in the array
58/// as shown in the following diagram. The logical values
59/// are shown on the left, and the actual `FixedSizeListArray` encoding on the right
60///
61/// ```text
62///                                 ┌ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ┐
63///                                                         ┌ ─ ─ ─ ─ ─ ─ ─ ─┐
64///  ┌─────────────┐                │     ┌───┐               ┌───┐ ┌──────┐      │
65///  │   [A,B]     │                      │ 1 │             │ │ 1 │ │  A   │ │ 0
66///  ├─────────────┤                │     ├───┤               ├───┤ ├──────┤      │
67///  │    NULL     │                      │ 0 │             │ │ 1 │ │  B   │ │ 1
68///  ├─────────────┤                │     ├───┤               ├───┤ ├──────┤      │
69///  │  [C,NULL]   │                      │ 1 │             │ │ 0 │ │ ???? │ │ 2
70///  └─────────────┘                │     └───┘               ├───┤ ├──────┤      │
71///                                                         | │ 0 │ │ ???? │ │ 3
72///  Logical Values                 │   Validity              ├───┤ ├──────┤      │
73///                                     (nulls)             │ │ 1 │ │  C   │ │ 4
74///                                 │                         ├───┤ ├──────┤      │
75///                                                         │ │ 0 │ │ ???? │ │ 5
76///                                 │                         └───┘ └──────┘      │
77///                                                         │     Values     │
78///                                 │   FixedSizeListArray        (Array)         │
79///                                                         └ ─ ─ ─ ─ ─ ─ ─ ─┘
80///                                 └ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ┘
81/// ```
82///
83/// # Example
84///
85/// ```
86/// # use std::sync::Arc;
87/// # use arrow_array::{Array, FixedSizeListArray, Int32Array};
88/// # use arrow_data::ArrayData;
89/// # use arrow_schema::{DataType, Field};
90/// # use arrow_buffer::Buffer;
91/// // Construct a value array
92/// let value_data = ArrayData::builder(DataType::Int32)
93///     .len(9)
94///     .add_buffer(Buffer::from_slice_ref(&[0, 1, 2, 3, 4, 5, 6, 7, 8]))
95///     .build()
96///     .unwrap();
97/// let list_data_type = DataType::FixedSizeList(
98///     Arc::new(Field::new_list_field(DataType::Int32, false)),
99///     3,
100/// );
101/// let list_data = ArrayData::builder(list_data_type.clone())
102///     .len(3)
103///     .add_child_data(value_data.clone())
104///     .build()
105///     .unwrap();
106/// let list_array = FixedSizeListArray::from(list_data);
107/// let list0 = list_array.value(0);
108/// let list1 = list_array.value(1);
109/// let list2 = list_array.value(2);
110///
111/// assert_eq!( &[0, 1, 2], list0.as_any().downcast_ref::<Int32Array>().unwrap().values());
112/// assert_eq!( &[3, 4, 5], list1.as_any().downcast_ref::<Int32Array>().unwrap().values());
113/// assert_eq!( &[6, 7, 8], list2.as_any().downcast_ref::<Int32Array>().unwrap().values());
114/// ```
115///
116/// [`StringArray`]: crate::array::StringArray
117/// [fixed length lists]: https://arrow.apache.org/docs/format/Columnar.html#fixed-size-list-layout
118#[derive(Clone)]
119pub struct FixedSizeListArray {
120    data_type: DataType, // Must be DataType::FixedSizeList(value_length)
121    values: ArrayRef,
122    nulls: Option<NullBuffer>,
123    value_length: i32,
124    len: usize,
125}
126
127impl FixedSizeListArray {
128    /// Create a new [`FixedSizeListArray`] with `size` element size, panicking on failure.
129    ///
130    /// Note that if `size == 0` and `nulls` is `None` (a degenerate, non-nullable
131    /// `FixedSizeListArray`), this function will set the length of the array to 0.
132    ///
133    /// If you would like to have a degenerate, non-nullable `FixedSizeListArray` with arbitrary
134    /// length, use the [`try_new_with_length()`] constructor.
135    ///
136    /// [`try_new_with_length()`]: Self::try_new_with_length
137    ///
138    /// # Panics
139    ///
140    /// Panics if [`Self::try_new`] returns an error
141    pub fn new(field: FieldRef, size: i32, values: ArrayRef, nulls: Option<NullBuffer>) -> Self {
142        Self::try_new(field, size, values, nulls).unwrap()
143    }
144
145    /// Create a new [`FixedSizeListArray`] from the provided parts without validation.
146    ///
147    /// # Safety
148    /// - `size >= 0`
149    /// - `values.len() == len * size as usize`
150    /// - `nulls.len() == len` if `nulls` is `Some`
151    /// - `field.data_type() == values.data_type()`
152    pub unsafe fn new_unchecked(
153        field: FieldRef,
154        size: i32,
155        values: ArrayRef,
156        nulls: Option<NullBuffer>,
157        len: usize,
158    ) -> Self {
159        if cfg!(feature = "force_validate") {
160            return Self::try_new_with_length(field, size, values, nulls, len).unwrap();
161        }
162        Self {
163            data_type: DataType::FixedSizeList(field, size),
164            values,
165            value_length: size,
166            nulls,
167            len,
168        }
169    }
170
171    /// Create a new [`FixedSizeListArray`] from the provided parts, returning an error on failure.
172    ///
173    /// Note that if `size == 0` and `nulls` is `None` (a degenerate, non-nullable
174    /// `FixedSizeListArray`), this function will set the length of the array to 0.
175    ///
176    /// If you would like to have a degenerate, non-nullable `FixedSizeListArray` with arbitrary
177    /// length, use the [`try_new_with_length()`] constructor.
178    ///
179    /// [`try_new_with_length()`]: Self::try_new_with_length
180    ///
181    /// # Errors
182    ///
183    /// * `size < 0`
184    /// * `values.len() != nulls.len() * size` if `nulls` is `Some`
185    /// * `values.data_type() != field.data_type()`
186    /// * `!field.is_nullable() && !nulls.expand(size).contains(values.logical_nulls())`
187    pub fn try_new(
188        field: FieldRef,
189        size: i32,
190        values: ArrayRef,
191        nulls: Option<NullBuffer>,
192    ) -> Result<Self, ArrowError> {
193        let s = size.to_usize().ok_or_else(|| {
194            ArrowError::InvalidArgumentError(format!("Size cannot be negative, got {size}"))
195        })?;
196
197        if s == 0 {
198            // Note that for degenerate (`size == 0`) and non-nullable `FixedSizeList`s, we will set
199            // the length to 0 (`_or_default`).
200            let len = nulls.as_ref().map(|x| x.len()).unwrap_or_default();
201
202            Self::try_new_with_length(field, size, values, nulls, len)
203        } else {
204            if !values.len().is_multiple_of(s) {
205                return Err(ArrowError::InvalidArgumentError(format!(
206                    "Incorrect length of values buffer for FixedSizeListArray, \
207                     expected a multiple of {s} got {}",
208                    values.len(),
209                )));
210            }
211
212            let len = values.len() / s;
213
214            // Check that the null buffer length is correct (if it exists).
215            if let Some(null_buffer) = &nulls
216                && s * null_buffer.len() != values.len()
217            {
218                return Err(ArrowError::InvalidArgumentError(format!(
219                    "Incorrect length of values buffer for FixedSizeListArray, \
220                            expected {} got {}",
221                    s * null_buffer.len(),
222                    values.len(),
223                )));
224            }
225
226            Self::try_new_with_length(field, size, values, nulls, len)
227        }
228    }
229
230    /// Create a new [`FixedSizeListArray`] from the provided parts, returning an error on failure.
231    ///
232    /// This method exists to allow the construction of arbitrary length degenerate (`size == 0`)
233    /// and non-nullable `FixedSizeListArray`s. If you want a nullable `FixedSizeListArray`, then
234    /// you can use [`try_new()`] instead.
235    ///
236    /// [`try_new()`]: Self::try_new
237    ///
238    /// # Errors
239    ///
240    /// * `size < 0`
241    /// * `nulls.len() != len` if `nulls` is `Some`
242    /// * `values.len() != len * size`
243    /// * `values.data_type() != field.data_type()`
244    /// * `!field.is_nullable() && !nulls.expand(size).contains(values.logical_nulls())`
245    pub fn try_new_with_length(
246        field: FieldRef,
247        size: i32,
248        values: ArrayRef,
249        nulls: Option<NullBuffer>,
250        len: usize,
251    ) -> Result<Self, ArrowError> {
252        let s = size.to_usize().ok_or_else(|| {
253            ArrowError::InvalidArgumentError(format!("Size cannot be negative, got {size}"))
254        })?;
255
256        if let Some(null_buffer) = &nulls
257            && null_buffer.len() != len
258        {
259            return Err(ArrowError::InvalidArgumentError(format!(
260                "Invalid null buffer for FixedSizeListArray, expected {len} found {}",
261                null_buffer.len()
262            )));
263        }
264
265        if s == 0 && !values.is_empty() {
266            return Err(ArrowError::InvalidArgumentError(format!(
267                "An degenerate FixedSizeListArray should have no underlying values, found {} values",
268                values.len()
269            )));
270        }
271
272        if values.len() != len * s {
273            return Err(ArrowError::InvalidArgumentError(format!(
274                "Incorrect length of values buffer for FixedSizeListArray, expected {} got {}",
275                len * s,
276                values.len(),
277            )));
278        }
279
280        if field.data_type() != values.data_type() {
281            return Err(ArrowError::InvalidArgumentError(format!(
282                "FixedSizeListArray expected data type {} got {} for {:?}",
283                field.data_type(),
284                values.data_type(),
285                field.name()
286            )));
287        }
288
289        if let Some(a) = values.logical_nulls() {
290            let nulls_valid = field.is_nullable()
291                || nulls
292                    .as_ref()
293                    .is_some_and(|n| n.expand(size as _).contains(&a))
294                || (nulls.is_none() && a.null_count() == 0);
295
296            if !nulls_valid {
297                return Err(ArrowError::InvalidArgumentError(format!(
298                    "Found unmasked nulls for non-nullable FixedSizeListArray field {:?}",
299                    field.name()
300                )));
301            }
302        }
303
304        let data_type = DataType::FixedSizeList(field, size);
305        Ok(Self {
306            data_type,
307            values,
308            value_length: size,
309            nulls,
310            len,
311        })
312    }
313
314    /// Create a new [`FixedSizeListArray`] of length `len` where all values are null
315    ///
316    /// # Panics
317    ///
318    /// Panics if
319    ///
320    /// * `size < 0`
321    /// * `size * len` would overflow `usize`
322    pub fn new_null(field: FieldRef, size: i32, len: usize) -> Self {
323        let capacity = size.to_usize().unwrap().checked_mul(len).unwrap();
324        Self {
325            values: make_array(ArrayData::new_null(field.data_type(), capacity)),
326            data_type: DataType::FixedSizeList(field, size),
327            nulls: Some(NullBuffer::new_null(len)),
328            value_length: size,
329            len,
330        }
331    }
332
333    /// Deconstruct this array into its constituent parts
334    pub fn into_parts(self) -> (FieldRef, i32, ArrayRef, Option<NullBuffer>) {
335        let DataType::FixedSizeList(f, _) = self.data_type else {
336            unreachable!()
337        };
338        (f, self.value_length, self.values, self.nulls)
339    }
340
341    /// The field that describes the values of this list.
342    pub fn value_field(&self) -> &FieldRef {
343        match &self.data_type {
344            DataType::FixedSizeList(f, _) => f,
345            _ => unreachable!(),
346        }
347    }
348
349    /// Returns a reference to the values of this list.
350    pub fn values(&self) -> &ArrayRef {
351        &self.values
352    }
353
354    /// Returns a clone of the value type of this list.
355    pub fn value_type(&self) -> DataType {
356        self.values.data_type().clone()
357    }
358
359    /// Returns ith value of this list array.
360    ///
361    /// Note: This method does not check for nulls and the value is arbitrary
362    /// (but still well-defined) if [`is_null`](Self::is_null) returns true for the index.
363    ///
364    /// # Panics
365    /// Panics if index `i` is out of bounds
366    pub fn value(&self, i: usize) -> ArrayRef {
367        self.values
368            .slice(self.value_offset_at(i), self.value_length() as usize)
369    }
370
371    /// Returns the offset for value at index `i`.
372    ///
373    /// Note this doesn't do any bound checking, for performance reason.
374    #[inline]
375    pub fn value_offset(&self, i: usize) -> i32 {
376        self.value_offset_at(i) as i32
377    }
378
379    /// Returns the length for an element.
380    ///
381    /// All elements have the same length as the array is a fixed size.
382    #[inline]
383    pub const fn value_length(&self) -> i32 {
384        self.value_length
385    }
386
387    #[inline]
388    const fn value_offset_at(&self, i: usize) -> usize {
389        i * self.value_length as usize
390    }
391
392    /// Returns a zero-copy slice of this array with the indicated offset and length.
393    ///
394    /// # Panics
395    /// Panics if `offset + len > self.len()`
396    pub fn slice(&self, offset: usize, len: usize) -> Self {
397        assert!(
398            offset.saturating_add(len) <= self.len,
399            "the length + offset of the sliced FixedSizeListArray cannot exceed the existing length"
400        );
401        let size = self.value_length as usize;
402
403        Self {
404            data_type: self.data_type.clone(),
405            values: self.values.slice(offset * size, len * size),
406            nulls: self.nulls.as_ref().map(|n| n.slice(offset, len)),
407            value_length: self.value_length,
408            len,
409        }
410    }
411
412    /// Creates a [`FixedSizeListArray`] from an iterator of primitive values
413    /// # Example
414    /// ```
415    /// # use arrow_array::FixedSizeListArray;
416    /// # use arrow_array::types::Int32Type;
417    ///
418    /// let data = vec![
419    ///    Some(vec![Some(0), Some(1), Some(2)]),
420    ///    None,
421    ///    Some(vec![Some(3), None, Some(5)]),
422    ///    Some(vec![Some(6), Some(7), Some(45)]),
423    /// ];
424    /// let list_array = FixedSizeListArray::from_iter_primitive::<Int32Type, _, _>(data, 3);
425    /// println!("{:?}", list_array);
426    /// ```
427    pub fn from_iter_primitive<T, P, I>(iter: I, length: i32) -> Self
428    where
429        T: ArrowPrimitiveType,
430        P: IntoIterator<Item = Option<<T as ArrowPrimitiveType>::Native>>,
431        I: IntoIterator<Item = Option<P>>,
432    {
433        let l = length as usize;
434        let iter = iter.into_iter();
435        let size_hint = iter.size_hint().0;
436        let mut builder = FixedSizeListBuilder::with_capacity(
437            PrimitiveBuilder::<T>::with_capacity(size_hint * l),
438            length,
439            size_hint,
440        );
441
442        for i in iter {
443            match i {
444                Some(p) => {
445                    for t in p {
446                        builder.values().append_option(t);
447                    }
448                    builder.append(true);
449                }
450                None => {
451                    builder.values().append_nulls(l);
452                    builder.append(false)
453                }
454            }
455        }
456        builder.finish()
457    }
458
459    /// constructs a new iterator
460    pub fn iter(&self) -> FixedSizeListIter<'_> {
461        FixedSizeListIter::new(self)
462    }
463}
464
465impl<'a> IntoIterator for &'a FixedSizeListArray {
466    type Item = Option<ArrayRef>;
467    type IntoIter = FixedSizeListIter<'a>;
468
469    fn into_iter(self) -> Self::IntoIter {
470        FixedSizeListIter::new(self)
471    }
472}
473
474impl From<ArrayData> for FixedSizeListArray {
475    fn from(data: ArrayData) -> Self {
476        let (data_type, len, nulls, offset, _buffers, child_data) = data.into_parts();
477
478        let value_length = match data_type {
479            DataType::FixedSizeList(_, len) => len,
480            data_type => {
481                panic!(
482                    "FixedSizeListArray data should contain a FixedSizeList data type, got {data_type}"
483                )
484            }
485        };
486
487        let size = value_length as usize;
488        let values = make_array(child_data[0].slice(offset * size, len * size));
489        Self {
490            data_type,
491            values,
492            nulls,
493            value_length,
494            len,
495        }
496    }
497}
498
499impl From<FixedSizeListArray> for ArrayData {
500    fn from(array: FixedSizeListArray) -> Self {
501        let builder = ArrayDataBuilder::new(array.data_type)
502            .len(array.len)
503            .nulls(array.nulls)
504            .child_data(vec![array.values.to_data()]);
505
506        unsafe { builder.build_unchecked() }
507    }
508}
509
510/// SAFETY: Correctly implements the contract of Arrow Arrays
511unsafe impl Array for FixedSizeListArray {
512    fn as_any(&self) -> &dyn Any {
513        self
514    }
515
516    fn to_data(&self) -> ArrayData {
517        self.clone().into()
518    }
519
520    fn into_data(self) -> ArrayData {
521        self.into()
522    }
523
524    fn data_type(&self) -> &DataType {
525        &self.data_type
526    }
527
528    fn slice(&self, offset: usize, length: usize) -> ArrayRef {
529        Arc::new(self.slice(offset, length))
530    }
531
532    fn len(&self) -> usize {
533        self.len
534    }
535
536    fn is_empty(&self) -> bool {
537        self.len == 0
538    }
539
540    fn shrink_to_fit(&mut self) {
541        self.values.shrink_to_fit();
542        if let Some(nulls) = &mut self.nulls {
543            nulls.shrink_to_fit();
544        }
545    }
546
547    fn offset(&self) -> usize {
548        0
549    }
550
551    fn nulls(&self) -> Option<&NullBuffer> {
552        self.nulls.as_ref()
553    }
554
555    fn logical_null_count(&self) -> usize {
556        // More efficient that the default implementation
557        self.null_count()
558    }
559
560    fn get_buffer_memory_size(&self) -> usize {
561        let mut size = self.values.get_buffer_memory_size();
562        if let Some(n) = self.nulls.as_ref() {
563            size += n.buffer().capacity();
564        }
565        size
566    }
567
568    fn get_array_memory_size(&self) -> usize {
569        let mut size = std::mem::size_of::<Self>() + self.values.get_array_memory_size();
570        if let Some(n) = self.nulls.as_ref() {
571            size += n.buffer().capacity();
572        }
573        size
574    }
575
576    #[cfg(feature = "pool")]
577    fn claim(&self, pool: &dyn arrow_buffer::MemoryPool) {
578        self.values.claim(pool);
579        if let Some(nulls) = &self.nulls {
580            nulls.claim(pool);
581        }
582    }
583}
584
585impl super::ListLikeArray for FixedSizeListArray {
586    fn values(&self) -> &ArrayRef {
587        self.values()
588    }
589
590    fn element_range(&self, index: usize) -> std::ops::Range<usize> {
591        let value_length = self.value_length().as_usize();
592        let offset = index * value_length;
593        offset..(offset + value_length)
594    }
595}
596
597impl ArrayAccessor for FixedSizeListArray {
598    type Item = ArrayRef;
599
600    fn value(&self, index: usize) -> Self::Item {
601        FixedSizeListArray::value(self, index)
602    }
603
604    unsafe fn value_unchecked(&self, index: usize) -> Self::Item {
605        FixedSizeListArray::value(self, index)
606    }
607}
608
609impl std::fmt::Debug for FixedSizeListArray {
610    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
611        write!(f, "FixedSizeListArray<{}>\n[\n", self.value_length())?;
612        print_long_array(self, f, &mut |index, f| {
613            std::fmt::Debug::fmt(&self.value(index), f)
614        })?;
615        write!(f, "]")
616    }
617}
618
619impl ArrayAccessor for &FixedSizeListArray {
620    type Item = ArrayRef;
621
622    fn value(&self, index: usize) -> Self::Item {
623        FixedSizeListArray::value(self, index)
624    }
625
626    unsafe fn value_unchecked(&self, index: usize) -> Self::Item {
627        FixedSizeListArray::value(self, index)
628    }
629}
630
631#[cfg(test)]
632mod tests {
633    use arrow_buffer::{BooleanBuffer, Buffer, bit_util};
634    use arrow_schema::Field;
635
636    use crate::cast::AsArray;
637    use crate::types::Int32Type;
638    use crate::{Int32Array, new_empty_array};
639
640    use super::*;
641
642    #[test]
643    fn test_fixed_size_list_array() {
644        // Construct a value array
645        let value_data = ArrayData::builder(DataType::Int32)
646            .len(9)
647            .add_buffer(Buffer::from_slice_ref([0, 1, 2, 3, 4, 5, 6, 7, 8]))
648            .build()
649            .unwrap();
650
651        // Construct a list array from the above two
652        let list_data_type =
653            DataType::FixedSizeList(Arc::new(Field::new_list_field(DataType::Int32, false)), 3);
654        let list_data = ArrayData::builder(list_data_type.clone())
655            .len(3)
656            .add_child_data(value_data.clone())
657            .build()
658            .unwrap();
659        let list_array = FixedSizeListArray::from(list_data);
660
661        assert_eq!(value_data, list_array.values().to_data());
662        assert_eq!(DataType::Int32, list_array.value_type());
663        assert_eq!(3, list_array.len());
664        assert_eq!(0, list_array.null_count());
665        assert_eq!(6, list_array.value_offset(2));
666        assert_eq!(3, list_array.value_length());
667        assert_eq!(0, list_array.value(0).as_primitive::<Int32Type>().value(0));
668        for i in 0..3 {
669            assert!(list_array.is_valid(i));
670            assert!(!list_array.is_null(i));
671        }
672
673        // Now test with a non-zero offset
674        let list_data = ArrayData::builder(list_data_type)
675            .len(2)
676            .offset(1)
677            .add_child_data(value_data.clone())
678            .build()
679            .unwrap();
680        let list_array = FixedSizeListArray::from(list_data);
681
682        assert_eq!(value_data.slice(3, 6), list_array.values().to_data());
683        assert_eq!(DataType::Int32, list_array.value_type());
684        assert_eq!(2, list_array.len());
685        assert_eq!(0, list_array.null_count());
686        assert_eq!(3, list_array.value(0).as_primitive::<Int32Type>().value(0));
687        assert_eq!(3, list_array.value_offset(1));
688        assert_eq!(3, list_array.value_length());
689    }
690
691    #[test]
692    #[should_panic(expected = "assertion failed: end <= self.len()")]
693    // Different error messages, so skip for now
694    // https://github.com/apache/arrow-rs/issues/1545
695    #[cfg(not(feature = "force_validate"))]
696    fn test_fixed_size_list_array_unequal_children() {
697        // Construct a value array
698        let value_data = ArrayData::builder(DataType::Int32)
699            .len(8)
700            .add_buffer(Buffer::from_slice_ref([0, 1, 2, 3, 4, 5, 6, 7]))
701            .build()
702            .unwrap();
703
704        // Construct a list array from the above two
705        let list_data_type =
706            DataType::FixedSizeList(Arc::new(Field::new_list_field(DataType::Int32, false)), 3);
707        let list_data = unsafe {
708            ArrayData::builder(list_data_type)
709                .len(3)
710                .add_child_data(value_data)
711                .build_unchecked()
712        };
713        drop(FixedSizeListArray::from(list_data));
714    }
715
716    #[test]
717    fn test_fixed_size_list_array_slice() {
718        // Construct a value array
719        let value_data = ArrayData::builder(DataType::Int32)
720            .len(10)
721            .add_buffer(Buffer::from_slice_ref([0, 1, 2, 3, 4, 5, 6, 7, 8, 9]))
722            .build()
723            .unwrap();
724
725        // Set null buts for the nested array:
726        //  [[0, 1], null, null, [6, 7], [8, 9]]
727        // 01011001 00000001
728        let mut null_bits: [u8; 1] = [0; 1];
729        bit_util::set_bit(&mut null_bits, 0);
730        bit_util::set_bit(&mut null_bits, 3);
731        bit_util::set_bit(&mut null_bits, 4);
732
733        // Construct a fixed size list array from the above two
734        let list_data_type =
735            DataType::FixedSizeList(Arc::new(Field::new_list_field(DataType::Int32, false)), 2);
736        let list_data = ArrayData::builder(list_data_type)
737            .len(5)
738            .add_child_data(value_data.clone())
739            .null_bit_buffer(Some(Buffer::from(null_bits)))
740            .build()
741            .unwrap();
742        let list_array = FixedSizeListArray::from(list_data);
743
744        assert_eq!(value_data, list_array.values().to_data());
745        assert_eq!(DataType::Int32, list_array.value_type());
746        assert_eq!(5, list_array.len());
747        assert_eq!(2, list_array.null_count());
748        assert_eq!(6, list_array.value_offset(3));
749        assert_eq!(2, list_array.value_length());
750
751        let sliced_array = list_array.slice(1, 4);
752        assert_eq!(4, sliced_array.len());
753        assert_eq!(2, sliced_array.null_count());
754
755        for i in 0..sliced_array.len() {
756            if bit_util::get_bit(&null_bits, 1 + i) {
757                assert!(sliced_array.is_valid(i));
758            } else {
759                assert!(sliced_array.is_null(i));
760            }
761        }
762
763        // Check offset and length for each non-null value.
764        let sliced_list_array = sliced_array
765            .as_any()
766            .downcast_ref::<FixedSizeListArray>()
767            .unwrap();
768        assert_eq!(2, sliced_list_array.value_length());
769        assert_eq!(4, sliced_list_array.value_offset(2));
770        assert_eq!(6, sliced_list_array.value_offset(3));
771    }
772
773    #[test]
774    #[should_panic(expected = "the offset of the new Buffer cannot exceed the existing length")]
775    fn test_fixed_size_list_array_index_out_of_bound() {
776        // Construct a value array
777        let value_data = ArrayData::builder(DataType::Int32)
778            .len(10)
779            .add_buffer(Buffer::from_slice_ref([0, 1, 2, 3, 4, 5, 6, 7, 8, 9]))
780            .build()
781            .unwrap();
782
783        // Set null buts for the nested array:
784        //  [[0, 1], null, null, [6, 7], [8, 9]]
785        // 01011001 00000001
786        let mut null_bits: [u8; 1] = [0; 1];
787        bit_util::set_bit(&mut null_bits, 0);
788        bit_util::set_bit(&mut null_bits, 3);
789        bit_util::set_bit(&mut null_bits, 4);
790
791        // Construct a fixed size list array from the above two
792        let list_data_type =
793            DataType::FixedSizeList(Arc::new(Field::new_list_field(DataType::Int32, false)), 2);
794        let list_data = ArrayData::builder(list_data_type)
795            .len(5)
796            .add_child_data(value_data)
797            .null_bit_buffer(Some(Buffer::from(null_bits)))
798            .build()
799            .unwrap();
800        let list_array = FixedSizeListArray::from(list_data);
801
802        list_array.value(10);
803    }
804
805    #[test]
806    fn test_fixed_size_list_constructors() {
807        let values = Arc::new(Int32Array::from_iter([
808            Some(1),
809            Some(2),
810            None,
811            None,
812            Some(3),
813            Some(4),
814        ]));
815
816        let field = Arc::new(Field::new_list_field(DataType::Int32, true));
817        let list = FixedSizeListArray::new(field.clone(), 2, values.clone(), None);
818        assert_eq!(list.len(), 3);
819
820        let nulls = NullBuffer::new_null(3);
821        let list = FixedSizeListArray::new(field.clone(), 2, values.clone(), Some(nulls));
822        assert_eq!(list.len(), 3);
823
824        let list = FixedSizeListArray::new(field.clone(), 3, values.clone(), None);
825        assert_eq!(list.len(), 2);
826
827        let err = FixedSizeListArray::try_new(field.clone(), 4, values.clone(), None).unwrap_err();
828        assert_eq!(
829            err.to_string(),
830            "Invalid argument error: Incorrect length of values buffer for FixedSizeListArray, \
831             expected a multiple of 4 got 6",
832        );
833
834        let err =
835            FixedSizeListArray::try_new_with_length(field.clone(), 4, values.clone(), None, 1)
836                .unwrap_err();
837        assert_eq!(
838            err.to_string(),
839            "Invalid argument error: Incorrect length of values buffer for FixedSizeListArray, expected 4 got 6"
840        );
841
842        let err = FixedSizeListArray::try_new(field.clone(), -1, values.clone(), None).unwrap_err();
843        assert_eq!(
844            err.to_string(),
845            "Invalid argument error: Size cannot be negative, got -1"
846        );
847
848        let nulls = NullBuffer::new_null(2);
849        let err = FixedSizeListArray::try_new(field, 2, values.clone(), Some(nulls)).unwrap_err();
850        assert_eq!(
851            err.to_string(),
852            "Invalid argument error: Incorrect length of values buffer for FixedSizeListArray, expected 4 got 6"
853        );
854
855        let field = Arc::new(Field::new_list_field(DataType::Int32, false));
856        let err = FixedSizeListArray::try_new(field.clone(), 2, values.clone(), None).unwrap_err();
857        assert_eq!(
858            err.to_string(),
859            "Invalid argument error: Found unmasked nulls for non-nullable FixedSizeListArray field \"item\""
860        );
861
862        // Valid as nulls in child masked by parent
863        let nulls = NullBuffer::new(BooleanBuffer::new(Buffer::from([0b0000101]), 0, 3));
864        FixedSizeListArray::new(field, 2, values.clone(), Some(nulls));
865
866        let field = Arc::new(Field::new_list_field(DataType::Int64, true));
867        let err = FixedSizeListArray::try_new(field, 2, values, None).unwrap_err();
868        assert_eq!(
869            err.to_string(),
870            "Invalid argument error: FixedSizeListArray expected data type Int64 got Int32 for \"item\""
871        );
872    }
873
874    #[test]
875    fn degenerate_fixed_size_list() {
876        let field = Arc::new(Field::new_list_field(DataType::Int32, true));
877        let nulls = NullBuffer::new_null(2);
878        let values = new_empty_array(&DataType::Int32);
879        let list = FixedSizeListArray::new(field.clone(), 0, values.clone(), Some(nulls.clone()));
880        assert_eq!(list.len(), 2);
881
882        // Test invalid null buffer length.
883        let err = FixedSizeListArray::try_new_with_length(
884            field.clone(),
885            0,
886            values.clone(),
887            Some(nulls),
888            5,
889        )
890        .unwrap_err();
891        assert_eq!(
892            err.to_string(),
893            "Invalid argument error: Invalid null buffer for FixedSizeListArray, expected 5 found 2"
894        );
895
896        // Test non-empty values for degenerate list.
897        let non_empty_values = Arc::new(Int32Array::from(vec![1, 2, 3]));
898        let err =
899            FixedSizeListArray::try_new_with_length(field.clone(), 0, non_empty_values, None, 3)
900                .unwrap_err();
901        assert_eq!(
902            err.to_string(),
903            "Invalid argument error: An degenerate FixedSizeListArray should have no underlying values, found 3 values"
904        );
905    }
906
907    #[test]
908    fn test_fixed_size_list_new_null_len() {
909        let field = Arc::new(Field::new_list_field(DataType::Int32, true));
910        let array = FixedSizeListArray::new_null(field, 2, 5);
911        assert_eq!(array.len(), 5);
912    }
913}
arrow_array/array/fixed_size_list_array.rs

arrow_array/array/
fixed_size_list_array.rs
