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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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
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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 f = match self.data_type {
336            DataType::FixedSizeList(f, _) => f,
337            _ => unreachable!(),
338        };
339        (f, self.value_length, self.values, self.nulls)
340    }
341
342    /// The field that describes the values of this list.
343    pub fn value_field(&self) -> &FieldRef {
344        match &self.data_type {
345            DataType::FixedSizeList(f, _) => f,
346            _ => unreachable!(),
347        }
348    }
349
350    /// Returns a reference to the values of this list.
351    pub fn values(&self) -> &ArrayRef {
352        &self.values
353    }
354
355    /// Returns a clone of the value type of this list.
356    pub fn value_type(&self) -> DataType {
357        self.values.data_type().clone()
358    }
359
360    /// Returns ith value of this list array.
361    ///
362    /// Note: This method does not check for nulls and the value is arbitrary
363    /// (but still well-defined) if [`is_null`](Self::is_null) returns true for the index.
364    ///
365    /// # Panics
366    /// Panics if index `i` is out of bounds
367    pub fn value(&self, i: usize) -> ArrayRef {
368        self.values
369            .slice(self.value_offset_at(i), self.value_length() as usize)
370    }
371
372    /// Returns the offset for value at index `i`.
373    ///
374    /// Note this doesn't do any bound checking, for performance reason.
375    #[inline]
376    pub fn value_offset(&self, i: usize) -> i32 {
377        self.value_offset_at(i) as i32
378    }
379
380    /// Returns the length for an element.
381    ///
382    /// All elements have the same length as the array is a fixed size.
383    #[inline]
384    pub const fn value_length(&self) -> i32 {
385        self.value_length
386    }
387
388    #[inline]
389    const fn value_offset_at(&self, i: usize) -> usize {
390        i * self.value_length as usize
391    }
392
393    /// Returns a zero-copy slice of this array with the indicated offset and length.
394    ///
395    /// # Panics
396    /// Panics if `offset + len > self.len()`
397    pub fn slice(&self, offset: usize, len: usize) -> Self {
398        assert!(
399            offset.saturating_add(len) <= self.len,
400            "the length + offset of the sliced FixedSizeListArray cannot exceed the existing length"
401        );
402        let size = self.value_length as usize;
403
404        Self {
405            data_type: self.data_type.clone(),
406            values: self.values.slice(offset * size, len * size),
407            nulls: self.nulls.as_ref().map(|n| n.slice(offset, len)),
408            value_length: self.value_length,
409            len,
410        }
411    }
412
413    /// Creates a [`FixedSizeListArray`] from an iterator of primitive values
414    /// # Example
415    /// ```
416    /// # use arrow_array::FixedSizeListArray;
417    /// # use arrow_array::types::Int32Type;
418    ///
419    /// let data = vec![
420    ///    Some(vec![Some(0), Some(1), Some(2)]),
421    ///    None,
422    ///    Some(vec![Some(3), None, Some(5)]),
423    ///    Some(vec![Some(6), Some(7), Some(45)]),
424    /// ];
425    /// let list_array = FixedSizeListArray::from_iter_primitive::<Int32Type, _, _>(data, 3);
426    /// println!("{:?}", list_array);
427    /// ```
428    pub fn from_iter_primitive<T, P, I>(iter: I, length: i32) -> Self
429    where
430        T: ArrowPrimitiveType,
431        P: IntoIterator<Item = Option<<T as ArrowPrimitiveType>::Native>>,
432        I: IntoIterator<Item = Option<P>>,
433    {
434        let l = length as usize;
435        let iter = iter.into_iter();
436        let size_hint = iter.size_hint().0;
437        let mut builder = FixedSizeListBuilder::with_capacity(
438            PrimitiveBuilder::<T>::with_capacity(size_hint * l),
439            length,
440            size_hint,
441        );
442
443        for i in iter {
444            match i {
445                Some(p) => {
446                    for t in p {
447                        builder.values().append_option(t);
448                    }
449                    builder.append(true);
450                }
451                None => {
452                    builder.values().append_nulls(l);
453                    builder.append(false)
454                }
455            }
456        }
457        builder.finish()
458    }
459
460    /// constructs a new iterator
461    pub fn iter(&self) -> FixedSizeListIter<'_> {
462        FixedSizeListIter::new(self)
463    }
464}
465
466impl From<ArrayData> for FixedSizeListArray {
467    fn from(data: ArrayData) -> Self {
468        let (data_type, len, nulls, offset, _buffers, child_data) = data.into_parts();
469
470        let value_length = match data_type {
471            DataType::FixedSizeList(_, len) => len,
472            data_type => {
473                panic!(
474                    "FixedSizeListArray data should contain a FixedSizeList data type, got {data_type}"
475                )
476            }
477        };
478
479        let size = value_length as usize;
480        let values = make_array(child_data[0].slice(offset * size, len * size));
481        Self {
482            data_type,
483            values,
484            nulls,
485            value_length,
486            len,
487        }
488    }
489}
490
491impl From<FixedSizeListArray> for ArrayData {
492    fn from(array: FixedSizeListArray) -> Self {
493        let builder = ArrayDataBuilder::new(array.data_type)
494            .len(array.len)
495            .nulls(array.nulls)
496            .child_data(vec![array.values.to_data()]);
497
498        unsafe { builder.build_unchecked() }
499    }
500}
501
502/// SAFETY: Correctly implements the contract of Arrow Arrays
503unsafe impl Array for FixedSizeListArray {
504    fn as_any(&self) -> &dyn Any {
505        self
506    }
507
508    fn to_data(&self) -> ArrayData {
509        self.clone().into()
510    }
511
512    fn into_data(self) -> ArrayData {
513        self.into()
514    }
515
516    fn data_type(&self) -> &DataType {
517        &self.data_type
518    }
519
520    fn slice(&self, offset: usize, length: usize) -> ArrayRef {
521        Arc::new(self.slice(offset, length))
522    }
523
524    fn len(&self) -> usize {
525        self.len
526    }
527
528    fn is_empty(&self) -> bool {
529        self.len == 0
530    }
531
532    fn shrink_to_fit(&mut self) {
533        self.values.shrink_to_fit();
534        if let Some(nulls) = &mut self.nulls {
535            nulls.shrink_to_fit();
536        }
537    }
538
539    fn offset(&self) -> usize {
540        0
541    }
542
543    fn nulls(&self) -> Option<&NullBuffer> {
544        self.nulls.as_ref()
545    }
546
547    fn logical_null_count(&self) -> usize {
548        // More efficient that the default implementation
549        self.null_count()
550    }
551
552    fn get_buffer_memory_size(&self) -> usize {
553        let mut size = self.values.get_buffer_memory_size();
554        if let Some(n) = self.nulls.as_ref() {
555            size += n.buffer().capacity();
556        }
557        size
558    }
559
560    fn get_array_memory_size(&self) -> usize {
561        let mut size = std::mem::size_of::<Self>() + self.values.get_array_memory_size();
562        if let Some(n) = self.nulls.as_ref() {
563            size += n.buffer().capacity();
564        }
565        size
566    }
567
568    #[cfg(feature = "pool")]
569    fn claim(&self, pool: &dyn arrow_buffer::MemoryPool) {
570        self.values.claim(pool);
571        if let Some(nulls) = &self.nulls {
572            nulls.claim(pool);
573        }
574    }
575}
576
577impl super::ListLikeArray for FixedSizeListArray {
578    fn values(&self) -> &ArrayRef {
579        self.values()
580    }
581
582    fn element_range(&self, index: usize) -> std::ops::Range<usize> {
583        let value_length = self.value_length().as_usize();
584        let offset = index * value_length;
585        offset..(offset + value_length)
586    }
587}
588
589impl ArrayAccessor for FixedSizeListArray {
590    type Item = ArrayRef;
591
592    fn value(&self, index: usize) -> Self::Item {
593        FixedSizeListArray::value(self, index)
594    }
595
596    unsafe fn value_unchecked(&self, index: usize) -> Self::Item {
597        FixedSizeListArray::value(self, index)
598    }
599}
600
601impl std::fmt::Debug for FixedSizeListArray {
602    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
603        write!(f, "FixedSizeListArray<{}>\n[\n", self.value_length())?;
604        print_long_array(self, f, |array, index, f| {
605            std::fmt::Debug::fmt(&array.value(index), f)
606        })?;
607        write!(f, "]")
608    }
609}
610
611impl ArrayAccessor for &FixedSizeListArray {
612    type Item = ArrayRef;
613
614    fn value(&self, index: usize) -> Self::Item {
615        FixedSizeListArray::value(self, index)
616    }
617
618    unsafe fn value_unchecked(&self, index: usize) -> Self::Item {
619        FixedSizeListArray::value(self, index)
620    }
621}
622
623#[cfg(test)]
624mod tests {
625    use arrow_buffer::{BooleanBuffer, Buffer, bit_util};
626    use arrow_schema::Field;
627
628    use crate::cast::AsArray;
629    use crate::types::Int32Type;
630    use crate::{Int32Array, new_empty_array};
631
632    use super::*;
633
634    #[test]
635    fn test_fixed_size_list_array() {
636        // Construct a value array
637        let value_data = ArrayData::builder(DataType::Int32)
638            .len(9)
639            .add_buffer(Buffer::from_slice_ref([0, 1, 2, 3, 4, 5, 6, 7, 8]))
640            .build()
641            .unwrap();
642
643        // Construct a list array from the above two
644        let list_data_type =
645            DataType::FixedSizeList(Arc::new(Field::new_list_field(DataType::Int32, false)), 3);
646        let list_data = ArrayData::builder(list_data_type.clone())
647            .len(3)
648            .add_child_data(value_data.clone())
649            .build()
650            .unwrap();
651        let list_array = FixedSizeListArray::from(list_data);
652
653        assert_eq!(value_data, list_array.values().to_data());
654        assert_eq!(DataType::Int32, list_array.value_type());
655        assert_eq!(3, list_array.len());
656        assert_eq!(0, list_array.null_count());
657        assert_eq!(6, list_array.value_offset(2));
658        assert_eq!(3, list_array.value_length());
659        assert_eq!(0, list_array.value(0).as_primitive::<Int32Type>().value(0));
660        for i in 0..3 {
661            assert!(list_array.is_valid(i));
662            assert!(!list_array.is_null(i));
663        }
664
665        // Now test with a non-zero offset
666        let list_data = ArrayData::builder(list_data_type)
667            .len(2)
668            .offset(1)
669            .add_child_data(value_data.clone())
670            .build()
671            .unwrap();
672        let list_array = FixedSizeListArray::from(list_data);
673
674        assert_eq!(value_data.slice(3, 6), list_array.values().to_data());
675        assert_eq!(DataType::Int32, list_array.value_type());
676        assert_eq!(2, list_array.len());
677        assert_eq!(0, list_array.null_count());
678        assert_eq!(3, list_array.value(0).as_primitive::<Int32Type>().value(0));
679        assert_eq!(3, list_array.value_offset(1));
680        assert_eq!(3, list_array.value_length());
681    }
682
683    #[test]
684    #[should_panic(expected = "assertion failed: end <= self.len()")]
685    // Different error messages, so skip for now
686    // https://github.com/apache/arrow-rs/issues/1545
687    #[cfg(not(feature = "force_validate"))]
688    fn test_fixed_size_list_array_unequal_children() {
689        // Construct a value array
690        let value_data = ArrayData::builder(DataType::Int32)
691            .len(8)
692            .add_buffer(Buffer::from_slice_ref([0, 1, 2, 3, 4, 5, 6, 7]))
693            .build()
694            .unwrap();
695
696        // Construct a list array from the above two
697        let list_data_type =
698            DataType::FixedSizeList(Arc::new(Field::new_list_field(DataType::Int32, false)), 3);
699        let list_data = unsafe {
700            ArrayData::builder(list_data_type)
701                .len(3)
702                .add_child_data(value_data)
703                .build_unchecked()
704        };
705        drop(FixedSizeListArray::from(list_data));
706    }
707
708    #[test]
709    fn test_fixed_size_list_array_slice() {
710        // Construct a value array
711        let value_data = ArrayData::builder(DataType::Int32)
712            .len(10)
713            .add_buffer(Buffer::from_slice_ref([0, 1, 2, 3, 4, 5, 6, 7, 8, 9]))
714            .build()
715            .unwrap();
716
717        // Set null buts for the nested array:
718        //  [[0, 1], null, null, [6, 7], [8, 9]]
719        // 01011001 00000001
720        let mut null_bits: [u8; 1] = [0; 1];
721        bit_util::set_bit(&mut null_bits, 0);
722        bit_util::set_bit(&mut null_bits, 3);
723        bit_util::set_bit(&mut null_bits, 4);
724
725        // Construct a fixed size list array from the above two
726        let list_data_type =
727            DataType::FixedSizeList(Arc::new(Field::new_list_field(DataType::Int32, false)), 2);
728        let list_data = ArrayData::builder(list_data_type)
729            .len(5)
730            .add_child_data(value_data.clone())
731            .null_bit_buffer(Some(Buffer::from(null_bits)))
732            .build()
733            .unwrap();
734        let list_array = FixedSizeListArray::from(list_data);
735
736        assert_eq!(value_data, list_array.values().to_data());
737        assert_eq!(DataType::Int32, list_array.value_type());
738        assert_eq!(5, list_array.len());
739        assert_eq!(2, list_array.null_count());
740        assert_eq!(6, list_array.value_offset(3));
741        assert_eq!(2, list_array.value_length());
742
743        let sliced_array = list_array.slice(1, 4);
744        assert_eq!(4, sliced_array.len());
745        assert_eq!(2, sliced_array.null_count());
746
747        for i in 0..sliced_array.len() {
748            if bit_util::get_bit(&null_bits, 1 + i) {
749                assert!(sliced_array.is_valid(i));
750            } else {
751                assert!(sliced_array.is_null(i));
752            }
753        }
754
755        // Check offset and length for each non-null value.
756        let sliced_list_array = sliced_array
757            .as_any()
758            .downcast_ref::<FixedSizeListArray>()
759            .unwrap();
760        assert_eq!(2, sliced_list_array.value_length());
761        assert_eq!(4, sliced_list_array.value_offset(2));
762        assert_eq!(6, sliced_list_array.value_offset(3));
763    }
764
765    #[test]
766    #[should_panic(expected = "the offset of the new Buffer cannot exceed the existing length")]
767    fn test_fixed_size_list_array_index_out_of_bound() {
768        // Construct a value array
769        let value_data = ArrayData::builder(DataType::Int32)
770            .len(10)
771            .add_buffer(Buffer::from_slice_ref([0, 1, 2, 3, 4, 5, 6, 7, 8, 9]))
772            .build()
773            .unwrap();
774
775        // Set null buts for the nested array:
776        //  [[0, 1], null, null, [6, 7], [8, 9]]
777        // 01011001 00000001
778        let mut null_bits: [u8; 1] = [0; 1];
779        bit_util::set_bit(&mut null_bits, 0);
780        bit_util::set_bit(&mut null_bits, 3);
781        bit_util::set_bit(&mut null_bits, 4);
782
783        // Construct a fixed size list array from the above two
784        let list_data_type =
785            DataType::FixedSizeList(Arc::new(Field::new_list_field(DataType::Int32, false)), 2);
786        let list_data = ArrayData::builder(list_data_type)
787            .len(5)
788            .add_child_data(value_data)
789            .null_bit_buffer(Some(Buffer::from(null_bits)))
790            .build()
791            .unwrap();
792        let list_array = FixedSizeListArray::from(list_data);
793
794        list_array.value(10);
795    }
796
797    #[test]
798    fn test_fixed_size_list_constructors() {
799        let values = Arc::new(Int32Array::from_iter([
800            Some(1),
801            Some(2),
802            None,
803            None,
804            Some(3),
805            Some(4),
806        ]));
807
808        let field = Arc::new(Field::new_list_field(DataType::Int32, true));
809        let list = FixedSizeListArray::new(field.clone(), 2, values.clone(), None);
810        assert_eq!(list.len(), 3);
811
812        let nulls = NullBuffer::new_null(3);
813        let list = FixedSizeListArray::new(field.clone(), 2, values.clone(), Some(nulls));
814        assert_eq!(list.len(), 3);
815
816        let list = FixedSizeListArray::new(field.clone(), 3, values.clone(), None);
817        assert_eq!(list.len(), 2);
818
819        let err = FixedSizeListArray::try_new(field.clone(), 4, values.clone(), None).unwrap_err();
820        assert_eq!(
821            err.to_string(),
822            "Invalid argument error: Incorrect length of values buffer for FixedSizeListArray, \
823             expected a multiple of 4 got 6",
824        );
825
826        let err =
827            FixedSizeListArray::try_new_with_length(field.clone(), 4, values.clone(), None, 1)
828                .unwrap_err();
829        assert_eq!(
830            err.to_string(),
831            "Invalid argument error: Incorrect length of values buffer for FixedSizeListArray, expected 4 got 6"
832        );
833
834        let err = FixedSizeListArray::try_new(field.clone(), -1, values.clone(), None).unwrap_err();
835        assert_eq!(
836            err.to_string(),
837            "Invalid argument error: Size cannot be negative, got -1"
838        );
839
840        let nulls = NullBuffer::new_null(2);
841        let err = FixedSizeListArray::try_new(field, 2, values.clone(), Some(nulls)).unwrap_err();
842        assert_eq!(
843            err.to_string(),
844            "Invalid argument error: Incorrect length of values buffer for FixedSizeListArray, expected 4 got 6"
845        );
846
847        let field = Arc::new(Field::new_list_field(DataType::Int32, false));
848        let err = FixedSizeListArray::try_new(field.clone(), 2, values.clone(), None).unwrap_err();
849        assert_eq!(
850            err.to_string(),
851            "Invalid argument error: Found unmasked nulls for non-nullable FixedSizeListArray field \"item\""
852        );
853
854        // Valid as nulls in child masked by parent
855        let nulls = NullBuffer::new(BooleanBuffer::new(Buffer::from([0b0000101]), 0, 3));
856        FixedSizeListArray::new(field, 2, values.clone(), Some(nulls));
857
858        let field = Arc::new(Field::new_list_field(DataType::Int64, true));
859        let err = FixedSizeListArray::try_new(field, 2, values, None).unwrap_err();
860        assert_eq!(
861            err.to_string(),
862            "Invalid argument error: FixedSizeListArray expected data type Int64 got Int32 for \"item\""
863        );
864    }
865
866    #[test]
867    fn degenerate_fixed_size_list() {
868        let field = Arc::new(Field::new_list_field(DataType::Int32, true));
869        let nulls = NullBuffer::new_null(2);
870        let values = new_empty_array(&DataType::Int32);
871        let list = FixedSizeListArray::new(field.clone(), 0, values.clone(), Some(nulls.clone()));
872        assert_eq!(list.len(), 2);
873
874        // Test invalid null buffer length.
875        let err = FixedSizeListArray::try_new_with_length(
876            field.clone(),
877            0,
878            values.clone(),
879            Some(nulls),
880            5,
881        )
882        .unwrap_err();
883        assert_eq!(
884            err.to_string(),
885            "Invalid argument error: Invalid null buffer for FixedSizeListArray, expected 5 found 2"
886        );
887
888        // Test non-empty values for degenerate list.
889        let non_empty_values = Arc::new(Int32Array::from(vec![1, 2, 3]));
890        let err =
891            FixedSizeListArray::try_new_with_length(field.clone(), 0, non_empty_values, None, 3)
892                .unwrap_err();
893        assert_eq!(
894            err.to_string(),
895            "Invalid argument error: An degenerate FixedSizeListArray should have no underlying values, found 3 values"
896        );
897    }
898
899    #[test]
900    fn test_fixed_size_list_new_null_len() {
901        let field = Arc::new(Field::new_list_field(DataType::Int32, true));
902        let array = FixedSizeListArray::new_null(field, 2, 5);
903        assert_eq!(array.len(), 5);
904    }
905}
arrow_array/array/fixed_size_list_array.rs

arrow_array/array/
fixed_size_list_array.rs
