arrow_array/array/
fixed_size_list_array.rs

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5// to you under the Apache License, Version 2.0 (the
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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 size arrays](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, returning an error on failure.
146    ///
147    /// Note that if `size == 0` and `nulls` is `None` (a degenerate, non-nullable
148    /// `FixedSizeListArray`), this function will set the length of the array to 0.
149    ///
150    /// If you would like to have a degenerate, non-nullable `FixedSizeListArray` with arbitrary
151    /// length, use the [`try_new_with_length()`] constructor.
152    ///
153    /// [`try_new_with_length()`]: Self::try_new_with_length
154    ///
155    /// # Errors
156    ///
157    /// * `size < 0`
158    /// * `values.len() != nulls.len() * size` if `nulls` is `Some`
159    /// * `values.data_type() != field.data_type()`
160    /// * `!field.is_nullable() && !nulls.expand(size).contains(values.logical_nulls())`
161    pub fn try_new(
162        field: FieldRef,
163        size: i32,
164        values: ArrayRef,
165        nulls: Option<NullBuffer>,
166    ) -> Result<Self, ArrowError> {
167        let s = size.to_usize().ok_or_else(|| {
168            ArrowError::InvalidArgumentError(format!("Size cannot be negative, got {size}"))
169        })?;
170
171        if s == 0 {
172            // Note that for degenerate (`size == 0`) and non-nullable `FixedSizeList`s, we will set
173            // the length to 0 (`_or_default`).
174            let len = nulls.as_ref().map(|x| x.len()).unwrap_or_default();
175
176            Self::try_new_with_length(field, size, values, nulls, len)
177        } else {
178            if values.len() % s != 0 {
179                return Err(ArrowError::InvalidArgumentError(format!(
180                    "Incorrect length of values buffer for FixedSizeListArray, \
181                     expected a multiple of {s} got {}",
182                    values.len(),
183                )));
184            }
185
186            let len = values.len() / s;
187
188            // Check that the null buffer length is correct (if it exists).
189            if let Some(null_buffer) = &nulls {
190                if s * null_buffer.len() != values.len() {
191                    return Err(ArrowError::InvalidArgumentError(format!(
192                        "Incorrect length of values buffer for FixedSizeListArray, \
193                            expected {} got {}",
194                        s * null_buffer.len(),
195                        values.len(),
196                    )));
197                }
198            }
199
200            Self::try_new_with_length(field, size, values, nulls, len)
201        }
202    }
203
204    /// Create a new [`FixedSizeListArray`] from the provided parts, returning an error on failure.
205    ///
206    /// This method exists to allow the construction of arbitrary length degenerate (`size == 0`)
207    /// and non-nullable `FixedSizeListArray`s. If you want a nullable `FixedSizeListArray`, then
208    /// you can use [`try_new()`] instead.
209    ///
210    /// [`try_new()`]: Self::try_new
211    ///
212    /// # Errors
213    ///
214    /// * `size < 0`
215    /// * `nulls.len() != len` if `nulls` is `Some`
216    /// * `values.len() != len * size`
217    /// * `values.data_type() != field.data_type()`
218    /// * `!field.is_nullable() && !nulls.expand(size).contains(values.logical_nulls())`
219    pub fn try_new_with_length(
220        field: FieldRef,
221        size: i32,
222        values: ArrayRef,
223        nulls: Option<NullBuffer>,
224        len: usize,
225    ) -> Result<Self, ArrowError> {
226        let s = size.to_usize().ok_or_else(|| {
227            ArrowError::InvalidArgumentError(format!("Size cannot be negative, got {size}"))
228        })?;
229
230        if let Some(null_buffer) = &nulls {
231            if null_buffer.len() != len {
232                return Err(ArrowError::InvalidArgumentError(format!(
233                    "Invalid null buffer for FixedSizeListArray, expected {len} found {}",
234                    null_buffer.len()
235                )));
236            }
237        }
238
239        if s == 0 && !values.is_empty() {
240            return Err(ArrowError::InvalidArgumentError(format!(
241                "An degenerate FixedSizeListArray should have no underlying values, found {} values",
242                values.len()
243            )));
244        }
245
246        if values.len() != len * s {
247            return Err(ArrowError::InvalidArgumentError(format!(
248                "Incorrect length of values buffer for FixedSizeListArray, expected {} got {}",
249                len * s,
250                values.len(),
251            )));
252        }
253
254        if field.data_type() != values.data_type() {
255            return Err(ArrowError::InvalidArgumentError(format!(
256                "FixedSizeListArray expected data type {} got {} for {:?}",
257                field.data_type(),
258                values.data_type(),
259                field.name()
260            )));
261        }
262
263        if let Some(a) = values.logical_nulls() {
264            let nulls_valid = field.is_nullable()
265                || nulls
266                    .as_ref()
267                    .map(|n| n.expand(size as _).contains(&a))
268                    .unwrap_or_default()
269                || (nulls.is_none() && a.null_count() == 0);
270
271            if !nulls_valid {
272                return Err(ArrowError::InvalidArgumentError(format!(
273                    "Found unmasked nulls for non-nullable FixedSizeListArray field {:?}",
274                    field.name()
275                )));
276            }
277        }
278
279        let data_type = DataType::FixedSizeList(field, size);
280        Ok(Self {
281            data_type,
282            values,
283            value_length: size,
284            nulls,
285            len,
286        })
287    }
288
289    /// Create a new [`FixedSizeListArray`] of length `len` where all values are null
290    ///
291    /// # Panics
292    ///
293    /// Panics if
294    ///
295    /// * `size < 0`
296    /// * `size * len` would overflow `usize`
297    pub fn new_null(field: FieldRef, size: i32, len: usize) -> Self {
298        let capacity = size.to_usize().unwrap().checked_mul(len).unwrap();
299        Self {
300            values: make_array(ArrayData::new_null(field.data_type(), capacity)),
301            data_type: DataType::FixedSizeList(field, size),
302            nulls: Some(NullBuffer::new_null(len)),
303            value_length: size,
304            len,
305        }
306    }
307
308    /// Deconstruct this array into its constituent parts
309    pub fn into_parts(self) -> (FieldRef, i32, ArrayRef, Option<NullBuffer>) {
310        let f = match self.data_type {
311            DataType::FixedSizeList(f, _) => f,
312            _ => unreachable!(),
313        };
314        (f, self.value_length, self.values, self.nulls)
315    }
316
317    /// Returns a reference to the values of this list.
318    pub fn values(&self) -> &ArrayRef {
319        &self.values
320    }
321
322    /// Returns a clone of the value type of this list.
323    pub fn value_type(&self) -> DataType {
324        self.values.data_type().clone()
325    }
326
327    /// Returns ith value of this list array.
328    ///
329    /// Note: This method does not check for nulls and the value is arbitrary
330    /// (but still well-defined) if [`is_null`](Self::is_null) returns true for the index.
331    ///
332    /// # Panics
333    /// Panics if index `i` is out of bounds
334    pub fn value(&self, i: usize) -> ArrayRef {
335        self.values
336            .slice(self.value_offset_at(i), self.value_length() as usize)
337    }
338
339    /// Returns the offset for value at index `i`.
340    ///
341    /// Note this doesn't do any bound checking, for performance reason.
342    #[inline]
343    pub fn value_offset(&self, i: usize) -> i32 {
344        self.value_offset_at(i) as i32
345    }
346
347    /// Returns the length for an element.
348    ///
349    /// All elements have the same length as the array is a fixed size.
350    #[inline]
351    pub const fn value_length(&self) -> i32 {
352        self.value_length
353    }
354
355    #[inline]
356    const fn value_offset_at(&self, i: usize) -> usize {
357        i * self.value_length as usize
358    }
359
360    /// Returns a zero-copy slice of this array with the indicated offset and length.
361    pub fn slice(&self, offset: usize, len: usize) -> Self {
362        assert!(
363            offset.saturating_add(len) <= self.len,
364            "the length + offset of the sliced FixedSizeListArray cannot exceed the existing length"
365        );
366        let size = self.value_length as usize;
367
368        Self {
369            data_type: self.data_type.clone(),
370            values: self.values.slice(offset * size, len * size),
371            nulls: self.nulls.as_ref().map(|n| n.slice(offset, len)),
372            value_length: self.value_length,
373            len,
374        }
375    }
376
377    /// Creates a [`FixedSizeListArray`] from an iterator of primitive values
378    /// # Example
379    /// ```
380    /// # use arrow_array::FixedSizeListArray;
381    /// # use arrow_array::types::Int32Type;
382    ///
383    /// let data = vec![
384    ///    Some(vec![Some(0), Some(1), Some(2)]),
385    ///    None,
386    ///    Some(vec![Some(3), None, Some(5)]),
387    ///    Some(vec![Some(6), Some(7), Some(45)]),
388    /// ];
389    /// let list_array = FixedSizeListArray::from_iter_primitive::<Int32Type, _, _>(data, 3);
390    /// println!("{:?}", list_array);
391    /// ```
392    pub fn from_iter_primitive<T, P, I>(iter: I, length: i32) -> Self
393    where
394        T: ArrowPrimitiveType,
395        P: IntoIterator<Item = Option<<T as ArrowPrimitiveType>::Native>>,
396        I: IntoIterator<Item = Option<P>>,
397    {
398        let l = length as usize;
399        let iter = iter.into_iter();
400        let size_hint = iter.size_hint().0;
401        let mut builder = FixedSizeListBuilder::with_capacity(
402            PrimitiveBuilder::<T>::with_capacity(size_hint * l),
403            length,
404            size_hint,
405        );
406
407        for i in iter {
408            match i {
409                Some(p) => {
410                    for t in p {
411                        builder.values().append_option(t);
412                    }
413                    builder.append(true);
414                }
415                None => {
416                    builder.values().append_nulls(l);
417                    builder.append(false)
418                }
419            }
420        }
421        builder.finish()
422    }
423
424    /// constructs a new iterator
425    pub fn iter(&self) -> FixedSizeListIter<'_> {
426        FixedSizeListIter::new(self)
427    }
428}
429
430impl From<ArrayData> for FixedSizeListArray {
431    fn from(data: ArrayData) -> Self {
432        let value_length = match data.data_type() {
433            DataType::FixedSizeList(_, len) => *len,
434            data_type => {
435                panic!(
436                    "FixedSizeListArray data should contain a FixedSizeList data type, got {data_type}"
437                )
438            }
439        };
440
441        let size = value_length as usize;
442        let values =
443            make_array(data.child_data()[0].slice(data.offset() * size, data.len() * size));
444        Self {
445            data_type: data.data_type().clone(),
446            values,
447            nulls: data.nulls().cloned(),
448            value_length,
449            len: data.len(),
450        }
451    }
452}
453
454impl From<FixedSizeListArray> for ArrayData {
455    fn from(array: FixedSizeListArray) -> Self {
456        let builder = ArrayDataBuilder::new(array.data_type)
457            .len(array.len)
458            .nulls(array.nulls)
459            .child_data(vec![array.values.to_data()]);
460
461        unsafe { builder.build_unchecked() }
462    }
463}
464
465impl super::private::Sealed for FixedSizeListArray {}
466
467impl Array for FixedSizeListArray {
468    fn as_any(&self) -> &dyn Any {
469        self
470    }
471
472    fn to_data(&self) -> ArrayData {
473        self.clone().into()
474    }
475
476    fn into_data(self) -> ArrayData {
477        self.into()
478    }
479
480    fn data_type(&self) -> &DataType {
481        &self.data_type
482    }
483
484    fn slice(&self, offset: usize, length: usize) -> ArrayRef {
485        Arc::new(self.slice(offset, length))
486    }
487
488    fn len(&self) -> usize {
489        self.len
490    }
491
492    fn is_empty(&self) -> bool {
493        self.len == 0
494    }
495
496    fn shrink_to_fit(&mut self) {
497        self.values.shrink_to_fit();
498        if let Some(nulls) = &mut self.nulls {
499            nulls.shrink_to_fit();
500        }
501    }
502
503    fn offset(&self) -> usize {
504        0
505    }
506
507    fn nulls(&self) -> Option<&NullBuffer> {
508        self.nulls.as_ref()
509    }
510
511    fn logical_null_count(&self) -> usize {
512        // More efficient that the default implementation
513        self.null_count()
514    }
515
516    fn get_buffer_memory_size(&self) -> usize {
517        let mut size = self.values.get_buffer_memory_size();
518        if let Some(n) = self.nulls.as_ref() {
519            size += n.buffer().capacity();
520        }
521        size
522    }
523
524    fn get_array_memory_size(&self) -> usize {
525        let mut size = std::mem::size_of::<Self>() + self.values.get_array_memory_size();
526        if let Some(n) = self.nulls.as_ref() {
527            size += n.buffer().capacity();
528        }
529        size
530    }
531}
532
533impl ArrayAccessor for FixedSizeListArray {
534    type Item = ArrayRef;
535
536    fn value(&self, index: usize) -> Self::Item {
537        FixedSizeListArray::value(self, index)
538    }
539
540    unsafe fn value_unchecked(&self, index: usize) -> Self::Item {
541        FixedSizeListArray::value(self, index)
542    }
543}
544
545impl std::fmt::Debug for FixedSizeListArray {
546    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
547        write!(f, "FixedSizeListArray<{}>\n[\n", self.value_length())?;
548        print_long_array(self, f, |array, index, f| {
549            std::fmt::Debug::fmt(&array.value(index), f)
550        })?;
551        write!(f, "]")
552    }
553}
554
555impl ArrayAccessor for &FixedSizeListArray {
556    type Item = ArrayRef;
557
558    fn value(&self, index: usize) -> Self::Item {
559        FixedSizeListArray::value(self, index)
560    }
561
562    unsafe fn value_unchecked(&self, index: usize) -> Self::Item {
563        FixedSizeListArray::value(self, index)
564    }
565}
566
567#[cfg(test)]
568mod tests {
569    use arrow_buffer::{BooleanBuffer, Buffer, bit_util};
570    use arrow_schema::Field;
571
572    use crate::cast::AsArray;
573    use crate::types::Int32Type;
574    use crate::{Int32Array, new_empty_array};
575
576    use super::*;
577
578    #[test]
579    fn test_fixed_size_list_array() {
580        // Construct a value array
581        let value_data = ArrayData::builder(DataType::Int32)
582            .len(9)
583            .add_buffer(Buffer::from_slice_ref([0, 1, 2, 3, 4, 5, 6, 7, 8]))
584            .build()
585            .unwrap();
586
587        // Construct a list array from the above two
588        let list_data_type =
589            DataType::FixedSizeList(Arc::new(Field::new_list_field(DataType::Int32, false)), 3);
590        let list_data = ArrayData::builder(list_data_type.clone())
591            .len(3)
592            .add_child_data(value_data.clone())
593            .build()
594            .unwrap();
595        let list_array = FixedSizeListArray::from(list_data);
596
597        assert_eq!(value_data, list_array.values().to_data());
598        assert_eq!(DataType::Int32, list_array.value_type());
599        assert_eq!(3, list_array.len());
600        assert_eq!(0, list_array.null_count());
601        assert_eq!(6, list_array.value_offset(2));
602        assert_eq!(3, list_array.value_length());
603        assert_eq!(0, list_array.value(0).as_primitive::<Int32Type>().value(0));
604        for i in 0..3 {
605            assert!(list_array.is_valid(i));
606            assert!(!list_array.is_null(i));
607        }
608
609        // Now test with a non-zero offset
610        let list_data = ArrayData::builder(list_data_type)
611            .len(2)
612            .offset(1)
613            .add_child_data(value_data.clone())
614            .build()
615            .unwrap();
616        let list_array = FixedSizeListArray::from(list_data);
617
618        assert_eq!(value_data.slice(3, 6), list_array.values().to_data());
619        assert_eq!(DataType::Int32, list_array.value_type());
620        assert_eq!(2, list_array.len());
621        assert_eq!(0, list_array.null_count());
622        assert_eq!(3, list_array.value(0).as_primitive::<Int32Type>().value(0));
623        assert_eq!(3, list_array.value_offset(1));
624        assert_eq!(3, list_array.value_length());
625    }
626
627    #[test]
628    #[should_panic(expected = "assertion failed: (offset + length) <= self.len()")]
629    // Different error messages, so skip for now
630    // https://github.com/apache/arrow-rs/issues/1545
631    #[cfg(not(feature = "force_validate"))]
632    fn test_fixed_size_list_array_unequal_children() {
633        // Construct a value array
634        let value_data = ArrayData::builder(DataType::Int32)
635            .len(8)
636            .add_buffer(Buffer::from_slice_ref([0, 1, 2, 3, 4, 5, 6, 7]))
637            .build()
638            .unwrap();
639
640        // Construct a list array from the above two
641        let list_data_type =
642            DataType::FixedSizeList(Arc::new(Field::new_list_field(DataType::Int32, false)), 3);
643        let list_data = unsafe {
644            ArrayData::builder(list_data_type)
645                .len(3)
646                .add_child_data(value_data)
647                .build_unchecked()
648        };
649        drop(FixedSizeListArray::from(list_data));
650    }
651
652    #[test]
653    fn test_fixed_size_list_array_slice() {
654        // Construct a value array
655        let value_data = ArrayData::builder(DataType::Int32)
656            .len(10)
657            .add_buffer(Buffer::from_slice_ref([0, 1, 2, 3, 4, 5, 6, 7, 8, 9]))
658            .build()
659            .unwrap();
660
661        // Set null buts for the nested array:
662        //  [[0, 1], null, null, [6, 7], [8, 9]]
663        // 01011001 00000001
664        let mut null_bits: [u8; 1] = [0; 1];
665        bit_util::set_bit(&mut null_bits, 0);
666        bit_util::set_bit(&mut null_bits, 3);
667        bit_util::set_bit(&mut null_bits, 4);
668
669        // Construct a fixed size list array from the above two
670        let list_data_type =
671            DataType::FixedSizeList(Arc::new(Field::new_list_field(DataType::Int32, false)), 2);
672        let list_data = ArrayData::builder(list_data_type)
673            .len(5)
674            .add_child_data(value_data.clone())
675            .null_bit_buffer(Some(Buffer::from(null_bits)))
676            .build()
677            .unwrap();
678        let list_array = FixedSizeListArray::from(list_data);
679
680        assert_eq!(value_data, list_array.values().to_data());
681        assert_eq!(DataType::Int32, list_array.value_type());
682        assert_eq!(5, list_array.len());
683        assert_eq!(2, list_array.null_count());
684        assert_eq!(6, list_array.value_offset(3));
685        assert_eq!(2, list_array.value_length());
686
687        let sliced_array = list_array.slice(1, 4);
688        assert_eq!(4, sliced_array.len());
689        assert_eq!(2, sliced_array.null_count());
690
691        for i in 0..sliced_array.len() {
692            if bit_util::get_bit(&null_bits, 1 + i) {
693                assert!(sliced_array.is_valid(i));
694            } else {
695                assert!(sliced_array.is_null(i));
696            }
697        }
698
699        // Check offset and length for each non-null value.
700        let sliced_list_array = sliced_array
701            .as_any()
702            .downcast_ref::<FixedSizeListArray>()
703            .unwrap();
704        assert_eq!(2, sliced_list_array.value_length());
705        assert_eq!(4, sliced_list_array.value_offset(2));
706        assert_eq!(6, sliced_list_array.value_offset(3));
707    }
708
709    #[test]
710    #[should_panic(expected = "the offset of the new Buffer cannot exceed the existing length")]
711    fn test_fixed_size_list_array_index_out_of_bound() {
712        // Construct a value array
713        let value_data = ArrayData::builder(DataType::Int32)
714            .len(10)
715            .add_buffer(Buffer::from_slice_ref([0, 1, 2, 3, 4, 5, 6, 7, 8, 9]))
716            .build()
717            .unwrap();
718
719        // Set null buts for the nested array:
720        //  [[0, 1], null, null, [6, 7], [8, 9]]
721        // 01011001 00000001
722        let mut null_bits: [u8; 1] = [0; 1];
723        bit_util::set_bit(&mut null_bits, 0);
724        bit_util::set_bit(&mut null_bits, 3);
725        bit_util::set_bit(&mut null_bits, 4);
726
727        // Construct a fixed size list array from the above two
728        let list_data_type =
729            DataType::FixedSizeList(Arc::new(Field::new_list_field(DataType::Int32, false)), 2);
730        let list_data = ArrayData::builder(list_data_type)
731            .len(5)
732            .add_child_data(value_data)
733            .null_bit_buffer(Some(Buffer::from(null_bits)))
734            .build()
735            .unwrap();
736        let list_array = FixedSizeListArray::from(list_data);
737
738        list_array.value(10);
739    }
740
741    #[test]
742    fn test_fixed_size_list_constructors() {
743        let values = Arc::new(Int32Array::from_iter([
744            Some(1),
745            Some(2),
746            None,
747            None,
748            Some(3),
749            Some(4),
750        ]));
751
752        let field = Arc::new(Field::new_list_field(DataType::Int32, true));
753        let list = FixedSizeListArray::new(field.clone(), 2, values.clone(), None);
754        assert_eq!(list.len(), 3);
755
756        let nulls = NullBuffer::new_null(3);
757        let list = FixedSizeListArray::new(field.clone(), 2, values.clone(), Some(nulls));
758        assert_eq!(list.len(), 3);
759
760        let list = FixedSizeListArray::new(field.clone(), 3, values.clone(), None);
761        assert_eq!(list.len(), 2);
762
763        let err = FixedSizeListArray::try_new(field.clone(), 4, values.clone(), None).unwrap_err();
764        assert_eq!(
765            err.to_string(),
766            "Invalid argument error: Incorrect length of values buffer for FixedSizeListArray, \
767             expected a multiple of 4 got 6",
768        );
769
770        let err =
771            FixedSizeListArray::try_new_with_length(field.clone(), 4, values.clone(), None, 1)
772                .unwrap_err();
773        assert_eq!(
774            err.to_string(),
775            "Invalid argument error: Incorrect length of values buffer for FixedSizeListArray, expected 4 got 6"
776        );
777
778        let err = FixedSizeListArray::try_new(field.clone(), -1, values.clone(), None).unwrap_err();
779        assert_eq!(
780            err.to_string(),
781            "Invalid argument error: Size cannot be negative, got -1"
782        );
783
784        let nulls = NullBuffer::new_null(2);
785        let err = FixedSizeListArray::try_new(field, 2, values.clone(), Some(nulls)).unwrap_err();
786        assert_eq!(
787            err.to_string(),
788            "Invalid argument error: Incorrect length of values buffer for FixedSizeListArray, expected 4 got 6"
789        );
790
791        let field = Arc::new(Field::new_list_field(DataType::Int32, false));
792        let err = FixedSizeListArray::try_new(field.clone(), 2, values.clone(), None).unwrap_err();
793        assert_eq!(
794            err.to_string(),
795            "Invalid argument error: Found unmasked nulls for non-nullable FixedSizeListArray field \"item\""
796        );
797
798        // Valid as nulls in child masked by parent
799        let nulls = NullBuffer::new(BooleanBuffer::new(Buffer::from([0b0000101]), 0, 3));
800        FixedSizeListArray::new(field, 2, values.clone(), Some(nulls));
801
802        let field = Arc::new(Field::new_list_field(DataType::Int64, true));
803        let err = FixedSizeListArray::try_new(field, 2, values, None).unwrap_err();
804        assert_eq!(
805            err.to_string(),
806            "Invalid argument error: FixedSizeListArray expected data type Int64 got Int32 for \"item\""
807        );
808    }
809
810    #[test]
811    fn degenerate_fixed_size_list() {
812        let field = Arc::new(Field::new_list_field(DataType::Int32, true));
813        let nulls = NullBuffer::new_null(2);
814        let values = new_empty_array(&DataType::Int32);
815        let list = FixedSizeListArray::new(field.clone(), 0, values.clone(), Some(nulls.clone()));
816        assert_eq!(list.len(), 2);
817
818        // Test invalid null buffer length.
819        let err = FixedSizeListArray::try_new_with_length(
820            field.clone(),
821            0,
822            values.clone(),
823            Some(nulls),
824            5,
825        )
826        .unwrap_err();
827        assert_eq!(
828            err.to_string(),
829            "Invalid argument error: Invalid null buffer for FixedSizeListArray, expected 5 found 2"
830        );
831
832        // Test non-empty values for degenerate list.
833        let non_empty_values = Arc::new(Int32Array::from(vec![1, 2, 3]));
834        let err =
835            FixedSizeListArray::try_new_with_length(field.clone(), 0, non_empty_values, None, 3)
836                .unwrap_err();
837        assert_eq!(
838            err.to_string(),
839            "Invalid argument error: An degenerate FixedSizeListArray should have no underlying values, found 3 values"
840        );
841    }
842
843    #[test]
844    fn test_fixed_size_list_new_null_len() {
845        let field = Arc::new(Field::new_list_field(DataType::Int32, true));
846        let array = FixedSizeListArray::new_null(field, 2, 5);
847        assert_eq!(array.len(), 5);
848    }
849}
arrow_array/array/fixed_size_list_array.rs

arrow_array/array/
fixed_size_list_array.rs
