arrow_array/array/
list_array.rs

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1// Licensed to the Apache Software Foundation (ASF) under one
2// or more contributor license agreements.  See the NOTICE file
3// distributed with this work for additional information
4// regarding copyright ownership.  The ASF licenses this file
5// to you under the Apache License, Version 2.0 (the
6// "License"); you may not use this file except in compliance
7// with the License.  You may obtain a copy of the License at
8//
9//   http://www.apache.org/licenses/LICENSE-2.0
10//
11// Unless required by applicable law or agreed to in writing,
12// software distributed under the License is distributed on an
13// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
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::{get_offsets, make_array, print_long_array};
19use crate::builder::{GenericListBuilder, PrimitiveBuilder};
20use crate::{
21    iterator::GenericListArrayIter, new_empty_array, Array, ArrayAccessor, ArrayRef,
22    ArrowPrimitiveType, FixedSizeListArray,
23};
24use arrow_buffer::{ArrowNativeType, NullBuffer, OffsetBuffer};
25use arrow_data::{ArrayData, ArrayDataBuilder};
26use arrow_schema::{ArrowError, DataType, FieldRef};
27use num::Integer;
28use std::any::Any;
29use std::sync::Arc;
30
31/// A type that can be used within a variable-size array to encode offset information
32///
33/// See [`ListArray`], [`LargeListArray`], [`BinaryArray`], [`LargeBinaryArray`],
34/// [`StringArray`] and [`LargeStringArray`]
35///
36/// [`BinaryArray`]: crate::array::BinaryArray
37/// [`LargeBinaryArray`]: crate::array::LargeBinaryArray
38/// [`StringArray`]: crate::array::StringArray
39/// [`LargeStringArray`]: crate::array::LargeStringArray
40pub trait OffsetSizeTrait: ArrowNativeType + std::ops::AddAssign + Integer {
41    /// True for 64 bit offset size and false for 32 bit offset size
42    const IS_LARGE: bool;
43    /// Prefix for the offset size
44    const PREFIX: &'static str;
45}
46
47impl OffsetSizeTrait for i32 {
48    const IS_LARGE: bool = false;
49    const PREFIX: &'static str = "";
50}
51
52impl OffsetSizeTrait for i64 {
53    const IS_LARGE: bool = true;
54    const PREFIX: &'static str = "Large";
55}
56
57/// An array of [variable length lists], similar to JSON arrays
58/// (e.g. `["A", "B", "C"]`).
59///
60/// Lists are represented using `offsets` into a `values` child
61/// array. Offsets are stored in two adjacent entries of an
62/// [`OffsetBuffer`].
63///
64/// Arrow defines [`ListArray`] with `i32` offsets and
65/// [`LargeListArray`] with `i64` offsets.
66///
67/// Use [`GenericListBuilder`] to construct a [`GenericListArray`].
68///
69/// # Representation
70///
71/// A [`ListArray`] can represent a list of values of any other
72/// supported Arrow type. Each element of the `ListArray` itself is
73/// a list which may be empty, may contain NULL and non-null values,
74/// or may itself be NULL.
75///
76/// For example, the `ListArray` shown in the following diagram stores
77/// lists of strings. Note that `[]` represents an empty (length
78/// 0), but non NULL list.
79///
80/// ```text
81/// ┌─────────────┐
82/// │   [A,B,C]   │
83/// ├─────────────┤
84/// │     []      │
85/// ├─────────────┤
86/// │    NULL     │
87/// ├─────────────┤
88/// │     [D]     │
89/// ├─────────────┤
90/// │  [NULL, F]  │
91/// └─────────────┘
92/// ```
93///
94/// The `values` are stored in a child [`StringArray`] and the offsets
95/// are stored in an [`OffsetBuffer`] as shown in the following
96/// diagram. The logical values and offsets are shown on the left, and
97/// the actual `ListArray` encoding on the right.
98///
99/// ```text
100///                                         ┌ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─
101///                                                                 ┌ ─ ─ ─ ─ ─ ─ ┐    │
102///  ┌─────────────┐  ┌───────┐             │     ┌───┐   ┌───┐       ┌───┐ ┌───┐
103///  │   [A,B,C]   │  │ (0,3) │                   │ 1 │   │ 0 │     │ │ 1 │ │ A │ │ 0  │
104///  ├─────────────┤  ├───────┤             │     ├───┤   ├───┤       ├───┤ ├───┤
105///  │      []     │  │ (3,3) │                   │ 1 │   │ 3 │     │ │ 1 │ │ B │ │ 1  │
106///  ├─────────────┤  ├───────┤             │     ├───┤   ├───┤       ├───┤ ├───┤
107///  │    NULL     │  │ (3,4) │                   │ 0 │   │ 3 │     │ │ 1 │ │ C │ │ 2  │
108///  ├─────────────┤  ├───────┤             │     ├───┤   ├───┤       ├───┤ ├───┤
109///  │     [D]     │  │ (4,5) │                   │ 1 │   │ 4 │     │ │ ? │ │ ? │ │ 3  │
110///  ├─────────────┤  ├───────┤             │     ├───┤   ├───┤       ├───┤ ├───┤
111///  │  [NULL, F]  │  │ (5,7) │                   │ 1 │   │ 5 │     │ │ 1 │ │ D │ │ 4  │
112///  └─────────────┘  └───────┘             │     └───┘   ├───┤       ├───┤ ├───┤
113///                                                       │ 7 │     │ │ 0 │ │ ? │ │ 5  │
114///                                         │  Validity   └───┘       ├───┤ ├───┤
115///     Logical       Logical                  (nulls)   Offsets    │ │ 1 │ │ F │ │ 6  │
116///      Values       Offsets               │                         └───┘ └───┘
117///                                                                 │    Values   │    │
118///                 (offsets[i],            │   ListArray               (Array)
119///                offsets[i+1])                                    └ ─ ─ ─ ─ ─ ─ ┘    │
120///                                         └ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─
121///
122///
123/// ```
124///
125/// [`StringArray`]: crate::array::StringArray
126/// [variable length lists]: https://arrow.apache.org/docs/format/Columnar.html#variable-size-list-layout
127pub struct GenericListArray<OffsetSize: OffsetSizeTrait> {
128    data_type: DataType,
129    nulls: Option<NullBuffer>,
130    values: ArrayRef,
131    value_offsets: OffsetBuffer<OffsetSize>,
132}
133
134impl<OffsetSize: OffsetSizeTrait> Clone for GenericListArray<OffsetSize> {
135    fn clone(&self) -> Self {
136        Self {
137            data_type: self.data_type.clone(),
138            nulls: self.nulls.clone(),
139            values: self.values.clone(),
140            value_offsets: self.value_offsets.clone(),
141        }
142    }
143}
144
145impl<OffsetSize: OffsetSizeTrait> GenericListArray<OffsetSize> {
146    /// The data type constructor of list array.
147    /// The input is the schema of the child array and
148    /// the output is the [`DataType`], List or LargeList.
149    pub const DATA_TYPE_CONSTRUCTOR: fn(FieldRef) -> DataType = if OffsetSize::IS_LARGE {
150        DataType::LargeList
151    } else {
152        DataType::List
153    };
154
155    /// Create a new [`GenericListArray`] from the provided parts
156    ///
157    /// # Errors
158    ///
159    /// Errors if
160    ///
161    /// * `offsets.len() - 1 != nulls.len()`
162    /// * `offsets.last() > values.len()`
163    /// * `!field.is_nullable() && values.is_nullable()`
164    /// * `field.data_type() != values.data_type()`
165    pub fn try_new(
166        field: FieldRef,
167        offsets: OffsetBuffer<OffsetSize>,
168        values: ArrayRef,
169        nulls: Option<NullBuffer>,
170    ) -> Result<Self, ArrowError> {
171        let len = offsets.len() - 1; // Offsets guaranteed to not be empty
172        let end_offset = offsets.last().unwrap().as_usize();
173        // don't need to check other values of `offsets` because they are checked
174        // during construction of `OffsetBuffer`
175        if end_offset > values.len() {
176            return Err(ArrowError::InvalidArgumentError(format!(
177                "Max offset of {end_offset} exceeds length of values {}",
178                values.len()
179            )));
180        }
181
182        if let Some(n) = nulls.as_ref() {
183            if n.len() != len {
184                return Err(ArrowError::InvalidArgumentError(format!(
185                    "Incorrect length of null buffer for {}ListArray, expected {len} got {}",
186                    OffsetSize::PREFIX,
187                    n.len(),
188                )));
189            }
190        }
191        if !field.is_nullable() && values.is_nullable() {
192            return Err(ArrowError::InvalidArgumentError(format!(
193                "Non-nullable field of {}ListArray {:?} cannot contain nulls",
194                OffsetSize::PREFIX,
195                field.name()
196            )));
197        }
198
199        if field.data_type() != values.data_type() {
200            return Err(ArrowError::InvalidArgumentError(format!(
201                "{}ListArray expected data type {} got {} for {:?}",
202                OffsetSize::PREFIX,
203                field.data_type(),
204                values.data_type(),
205                field.name()
206            )));
207        }
208
209        Ok(Self {
210            data_type: Self::DATA_TYPE_CONSTRUCTOR(field),
211            nulls,
212            values,
213            value_offsets: offsets,
214        })
215    }
216
217    /// Create a new [`GenericListArray`] from the provided parts
218    ///
219    /// # Panics
220    ///
221    /// Panics if [`Self::try_new`] returns an error
222    pub fn new(
223        field: FieldRef,
224        offsets: OffsetBuffer<OffsetSize>,
225        values: ArrayRef,
226        nulls: Option<NullBuffer>,
227    ) -> Self {
228        Self::try_new(field, offsets, values, nulls).unwrap()
229    }
230
231    /// Create a new [`GenericListArray`] of length `len` where all values are null
232    pub fn new_null(field: FieldRef, len: usize) -> Self {
233        let values = new_empty_array(field.data_type());
234        Self {
235            data_type: Self::DATA_TYPE_CONSTRUCTOR(field),
236            nulls: Some(NullBuffer::new_null(len)),
237            value_offsets: OffsetBuffer::new_zeroed(len),
238            values,
239        }
240    }
241
242    /// Deconstruct this array into its constituent parts
243    pub fn into_parts(
244        self,
245    ) -> (
246        FieldRef,
247        OffsetBuffer<OffsetSize>,
248        ArrayRef,
249        Option<NullBuffer>,
250    ) {
251        let f = match self.data_type {
252            DataType::List(f) | DataType::LargeList(f) => f,
253            _ => unreachable!(),
254        };
255        (f, self.value_offsets, self.values, self.nulls)
256    }
257
258    /// Returns a reference to the offsets of this list
259    ///
260    /// Unlike [`Self::value_offsets`] this returns the [`OffsetBuffer`]
261    /// allowing for zero-copy cloning
262    #[inline]
263    pub fn offsets(&self) -> &OffsetBuffer<OffsetSize> {
264        &self.value_offsets
265    }
266
267    /// Returns a reference to the values of this list
268    #[inline]
269    pub fn values(&self) -> &ArrayRef {
270        &self.values
271    }
272
273    /// Returns a clone of the value type of this list.
274    pub fn value_type(&self) -> DataType {
275        self.values.data_type().clone()
276    }
277
278    /// Returns ith value of this list array.
279    /// # Safety
280    /// Caller must ensure that the index is within the array bounds
281    pub unsafe fn value_unchecked(&self, i: usize) -> ArrayRef {
282        let end = self.value_offsets().get_unchecked(i + 1).as_usize();
283        let start = self.value_offsets().get_unchecked(i).as_usize();
284        self.values.slice(start, end - start)
285    }
286
287    /// Returns ith value of this list array.
288    pub fn value(&self, i: usize) -> ArrayRef {
289        let end = self.value_offsets()[i + 1].as_usize();
290        let start = self.value_offsets()[i].as_usize();
291        self.values.slice(start, end - start)
292    }
293
294    /// Returns the offset values in the offsets buffer
295    #[inline]
296    pub fn value_offsets(&self) -> &[OffsetSize] {
297        &self.value_offsets
298    }
299
300    /// Returns the length for value at index `i`.
301    #[inline]
302    pub fn value_length(&self, i: usize) -> OffsetSize {
303        let offsets = self.value_offsets();
304        offsets[i + 1] - offsets[i]
305    }
306
307    /// constructs a new iterator
308    pub fn iter<'a>(&'a self) -> GenericListArrayIter<'a, OffsetSize> {
309        GenericListArrayIter::<'a, OffsetSize>::new(self)
310    }
311
312    #[inline]
313    fn get_type(data_type: &DataType) -> Option<&DataType> {
314        match (OffsetSize::IS_LARGE, data_type) {
315            (true, DataType::LargeList(child)) | (false, DataType::List(child)) => {
316                Some(child.data_type())
317            }
318            _ => None,
319        }
320    }
321
322    /// Returns a zero-copy slice of this array with the indicated offset and length.
323    pub fn slice(&self, offset: usize, length: usize) -> Self {
324        Self {
325            data_type: self.data_type.clone(),
326            nulls: self.nulls.as_ref().map(|n| n.slice(offset, length)),
327            values: self.values.clone(),
328            value_offsets: self.value_offsets.slice(offset, length),
329        }
330    }
331
332    /// Creates a [`GenericListArray`] from an iterator of primitive values
333    /// # Example
334    /// ```
335    /// # use arrow_array::ListArray;
336    /// # use arrow_array::types::Int32Type;
337    ///
338    /// let data = vec![
339    ///    Some(vec![Some(0), Some(1), Some(2)]),
340    ///    None,
341    ///    Some(vec![Some(3), None, Some(5)]),
342    ///    Some(vec![Some(6), Some(7)]),
343    /// ];
344    /// let list_array = ListArray::from_iter_primitive::<Int32Type, _, _>(data);
345    /// println!("{:?}", list_array);
346    /// ```
347    pub fn from_iter_primitive<T, P, I>(iter: I) -> Self
348    where
349        T: ArrowPrimitiveType,
350        P: IntoIterator<Item = Option<<T as ArrowPrimitiveType>::Native>>,
351        I: IntoIterator<Item = Option<P>>,
352    {
353        let iter = iter.into_iter();
354        let size_hint = iter.size_hint().0;
355        let mut builder =
356            GenericListBuilder::with_capacity(PrimitiveBuilder::<T>::new(), size_hint);
357
358        for i in iter {
359            match i {
360                Some(p) => {
361                    for t in p {
362                        builder.values().append_option(t);
363                    }
364                    builder.append(true);
365                }
366                None => builder.append(false),
367            }
368        }
369        builder.finish()
370    }
371}
372
373impl<OffsetSize: OffsetSizeTrait> From<ArrayData> for GenericListArray<OffsetSize> {
374    fn from(data: ArrayData) -> Self {
375        Self::try_new_from_array_data(data)
376            .expect("Expected infallible creation of GenericListArray from ArrayDataRef failed")
377    }
378}
379
380impl<OffsetSize: OffsetSizeTrait> From<GenericListArray<OffsetSize>> for ArrayData {
381    fn from(array: GenericListArray<OffsetSize>) -> Self {
382        let len = array.len();
383        let builder = ArrayDataBuilder::new(array.data_type)
384            .len(len)
385            .nulls(array.nulls)
386            .buffers(vec![array.value_offsets.into_inner().into_inner()])
387            .child_data(vec![array.values.to_data()]);
388
389        unsafe { builder.build_unchecked() }
390    }
391}
392
393impl<OffsetSize: OffsetSizeTrait> From<FixedSizeListArray> for GenericListArray<OffsetSize> {
394    fn from(value: FixedSizeListArray) -> Self {
395        let (field, size) = match value.data_type() {
396            DataType::FixedSizeList(f, size) => (f, *size as usize),
397            _ => unreachable!(),
398        };
399
400        let offsets = OffsetBuffer::from_lengths(std::iter::repeat(size).take(value.len()));
401
402        Self {
403            data_type: Self::DATA_TYPE_CONSTRUCTOR(field.clone()),
404            nulls: value.nulls().cloned(),
405            values: value.values().clone(),
406            value_offsets: offsets,
407        }
408    }
409}
410
411impl<OffsetSize: OffsetSizeTrait> GenericListArray<OffsetSize> {
412    fn try_new_from_array_data(data: ArrayData) -> Result<Self, ArrowError> {
413        if data.buffers().len() != 1 {
414            return Err(ArrowError::InvalidArgumentError(format!(
415                "ListArray data should contain a single buffer only (value offsets), had {}",
416                data.buffers().len()
417            )));
418        }
419
420        if data.child_data().len() != 1 {
421            return Err(ArrowError::InvalidArgumentError(format!(
422                "ListArray should contain a single child array (values array), had {}",
423                data.child_data().len()
424            )));
425        }
426
427        let values = data.child_data()[0].clone();
428
429        if let Some(child_data_type) = Self::get_type(data.data_type()) {
430            if values.data_type() != child_data_type {
431                return Err(ArrowError::InvalidArgumentError(format!(
432                    "[Large]ListArray's child datatype {:?} does not \
433                             correspond to the List's datatype {:?}",
434                    values.data_type(),
435                    child_data_type
436                )));
437            }
438        } else {
439            return Err(ArrowError::InvalidArgumentError(format!(
440                "[Large]ListArray's datatype must be [Large]ListArray(). It is {:?}",
441                data.data_type()
442            )));
443        }
444
445        let values = make_array(values);
446        // SAFETY:
447        // ArrayData is valid, and verified type above
448        let value_offsets = unsafe { get_offsets(&data) };
449
450        Ok(Self {
451            data_type: data.data_type().clone(),
452            nulls: data.nulls().cloned(),
453            values,
454            value_offsets,
455        })
456    }
457}
458
459impl<OffsetSize: OffsetSizeTrait> Array for GenericListArray<OffsetSize> {
460    fn as_any(&self) -> &dyn Any {
461        self
462    }
463
464    fn to_data(&self) -> ArrayData {
465        self.clone().into()
466    }
467
468    fn into_data(self) -> ArrayData {
469        self.into()
470    }
471
472    fn data_type(&self) -> &DataType {
473        &self.data_type
474    }
475
476    fn slice(&self, offset: usize, length: usize) -> ArrayRef {
477        Arc::new(self.slice(offset, length))
478    }
479
480    fn len(&self) -> usize {
481        self.value_offsets.len() - 1
482    }
483
484    fn is_empty(&self) -> bool {
485        self.value_offsets.len() <= 1
486    }
487
488    fn offset(&self) -> usize {
489        0
490    }
491
492    fn nulls(&self) -> Option<&NullBuffer> {
493        self.nulls.as_ref()
494    }
495
496    fn logical_null_count(&self) -> usize {
497        // More efficient that the default implementation
498        self.null_count()
499    }
500
501    fn get_buffer_memory_size(&self) -> usize {
502        let mut size = self.values.get_buffer_memory_size();
503        size += self.value_offsets.inner().inner().capacity();
504        if let Some(n) = self.nulls.as_ref() {
505            size += n.buffer().capacity();
506        }
507        size
508    }
509
510    fn get_array_memory_size(&self) -> usize {
511        let mut size = std::mem::size_of::<Self>() + self.values.get_array_memory_size();
512        size += self.value_offsets.inner().inner().capacity();
513        if let Some(n) = self.nulls.as_ref() {
514            size += n.buffer().capacity();
515        }
516        size
517    }
518}
519
520impl<OffsetSize: OffsetSizeTrait> ArrayAccessor for &GenericListArray<OffsetSize> {
521    type Item = ArrayRef;
522
523    fn value(&self, index: usize) -> Self::Item {
524        GenericListArray::value(self, index)
525    }
526
527    unsafe fn value_unchecked(&self, index: usize) -> Self::Item {
528        GenericListArray::value(self, index)
529    }
530}
531
532impl<OffsetSize: OffsetSizeTrait> std::fmt::Debug for GenericListArray<OffsetSize> {
533    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
534        let prefix = OffsetSize::PREFIX;
535
536        write!(f, "{prefix}ListArray\n[\n")?;
537        print_long_array(self, f, |array, index, f| {
538            std::fmt::Debug::fmt(&array.value(index), f)
539        })?;
540        write!(f, "]")
541    }
542}
543
544/// A [`GenericListArray`] of variable size lists, storing offsets as `i32`.
545///
546// See [`ListBuilder`](crate::builder::ListBuilder) for how to construct a [`ListArray`]
547pub type ListArray = GenericListArray<i32>;
548
549/// A [`GenericListArray`] of variable size lists, storing offsets as `i64`.
550///
551// See [`LargeListBuilder`](crate::builder::LargeListBuilder) for how to construct a [`LargeListArray`]
552pub type LargeListArray = GenericListArray<i64>;
553
554#[cfg(test)]
555mod tests {
556    use super::*;
557    use crate::builder::{FixedSizeListBuilder, Int32Builder, ListBuilder, UnionBuilder};
558    use crate::cast::AsArray;
559    use crate::types::Int32Type;
560    use crate::{Int32Array, Int64Array};
561    use arrow_buffer::{bit_util, Buffer, ScalarBuffer};
562    use arrow_schema::Field;
563
564    fn create_from_buffers() -> ListArray {
565        //  [[0, 1, 2], [3, 4, 5], [6, 7]]
566        let values = Int32Array::from(vec![0, 1, 2, 3, 4, 5, 6, 7]);
567        let offsets = OffsetBuffer::new(ScalarBuffer::from(vec![0, 3, 6, 8]));
568        let field = Arc::new(Field::new("item", DataType::Int32, true));
569        ListArray::new(field, offsets, Arc::new(values), None)
570    }
571
572    #[test]
573    fn test_from_iter_primitive() {
574        let data = vec![
575            Some(vec![Some(0), Some(1), Some(2)]),
576            Some(vec![Some(3), Some(4), Some(5)]),
577            Some(vec![Some(6), Some(7)]),
578        ];
579        let list_array = ListArray::from_iter_primitive::<Int32Type, _, _>(data);
580
581        let another = create_from_buffers();
582        assert_eq!(list_array, another)
583    }
584
585    #[test]
586    fn test_empty_list_array() {
587        // Construct an empty value array
588        let value_data = ArrayData::builder(DataType::Int32)
589            .len(0)
590            .add_buffer(Buffer::from([]))
591            .build()
592            .unwrap();
593
594        // Construct an empty offset buffer
595        let value_offsets = Buffer::from([]);
596
597        // Construct a list array from the above two
598        let list_data_type = DataType::List(Arc::new(Field::new("item", DataType::Int32, false)));
599        let list_data = ArrayData::builder(list_data_type)
600            .len(0)
601            .add_buffer(value_offsets)
602            .add_child_data(value_data)
603            .build()
604            .unwrap();
605
606        let list_array = ListArray::from(list_data);
607        assert_eq!(list_array.len(), 0)
608    }
609
610    #[test]
611    fn test_list_array() {
612        // Construct a value array
613        let value_data = ArrayData::builder(DataType::Int32)
614            .len(8)
615            .add_buffer(Buffer::from_slice_ref([0, 1, 2, 3, 4, 5, 6, 7]))
616            .build()
617            .unwrap();
618
619        // Construct a buffer for value offsets, for the nested array:
620        //  [[0, 1, 2], [3, 4, 5], [6, 7]]
621        let value_offsets = Buffer::from_slice_ref([0, 3, 6, 8]);
622
623        // Construct a list array from the above two
624        let list_data_type = DataType::List(Arc::new(Field::new("item", DataType::Int32, false)));
625        let list_data = ArrayData::builder(list_data_type.clone())
626            .len(3)
627            .add_buffer(value_offsets.clone())
628            .add_child_data(value_data.clone())
629            .build()
630            .unwrap();
631        let list_array = ListArray::from(list_data);
632
633        let values = list_array.values();
634        assert_eq!(value_data, values.to_data());
635        assert_eq!(DataType::Int32, list_array.value_type());
636        assert_eq!(3, list_array.len());
637        assert_eq!(0, list_array.null_count());
638        assert_eq!(6, list_array.value_offsets()[2]);
639        assert_eq!(2, list_array.value_length(2));
640        assert_eq!(0, list_array.value(0).as_primitive::<Int32Type>().value(0));
641        assert_eq!(
642            0,
643            unsafe { list_array.value_unchecked(0) }
644                .as_primitive::<Int32Type>()
645                .value(0)
646        );
647        for i in 0..3 {
648            assert!(list_array.is_valid(i));
649            assert!(!list_array.is_null(i));
650        }
651
652        // Now test with a non-zero offset (skip first element)
653        //  [[3, 4, 5], [6, 7]]
654        let list_data = ArrayData::builder(list_data_type)
655            .len(2)
656            .offset(1)
657            .add_buffer(value_offsets)
658            .add_child_data(value_data.clone())
659            .build()
660            .unwrap();
661        let list_array = ListArray::from(list_data);
662
663        let values = list_array.values();
664        assert_eq!(value_data, values.to_data());
665        assert_eq!(DataType::Int32, list_array.value_type());
666        assert_eq!(2, list_array.len());
667        assert_eq!(0, list_array.null_count());
668        assert_eq!(6, list_array.value_offsets()[1]);
669        assert_eq!(2, list_array.value_length(1));
670        assert_eq!(3, list_array.value(0).as_primitive::<Int32Type>().value(0));
671        assert_eq!(
672            3,
673            unsafe { list_array.value_unchecked(0) }
674                .as_primitive::<Int32Type>()
675                .value(0)
676        );
677    }
678
679    #[test]
680    fn test_large_list_array() {
681        // Construct a value array
682        let value_data = ArrayData::builder(DataType::Int32)
683            .len(8)
684            .add_buffer(Buffer::from_slice_ref([0, 1, 2, 3, 4, 5, 6, 7]))
685            .build()
686            .unwrap();
687
688        // Construct a buffer for value offsets, for the nested array:
689        //  [[0, 1, 2], [3, 4, 5], [6, 7]]
690        let value_offsets = Buffer::from_slice_ref([0i64, 3, 6, 8]);
691
692        // Construct a list array from the above two
693        let list_data_type = DataType::new_large_list(DataType::Int32, false);
694        let list_data = ArrayData::builder(list_data_type.clone())
695            .len(3)
696            .add_buffer(value_offsets.clone())
697            .add_child_data(value_data.clone())
698            .build()
699            .unwrap();
700        let list_array = LargeListArray::from(list_data);
701
702        let values = list_array.values();
703        assert_eq!(value_data, values.to_data());
704        assert_eq!(DataType::Int32, list_array.value_type());
705        assert_eq!(3, list_array.len());
706        assert_eq!(0, list_array.null_count());
707        assert_eq!(6, list_array.value_offsets()[2]);
708        assert_eq!(2, list_array.value_length(2));
709        assert_eq!(0, list_array.value(0).as_primitive::<Int32Type>().value(0));
710        assert_eq!(
711            0,
712            unsafe { list_array.value_unchecked(0) }
713                .as_primitive::<Int32Type>()
714                .value(0)
715        );
716        for i in 0..3 {
717            assert!(list_array.is_valid(i));
718            assert!(!list_array.is_null(i));
719        }
720
721        // Now test with a non-zero offset
722        //  [[3, 4, 5], [6, 7]]
723        let list_data = ArrayData::builder(list_data_type)
724            .len(2)
725            .offset(1)
726            .add_buffer(value_offsets)
727            .add_child_data(value_data.clone())
728            .build()
729            .unwrap();
730        let list_array = LargeListArray::from(list_data);
731
732        let values = list_array.values();
733        assert_eq!(value_data, values.to_data());
734        assert_eq!(DataType::Int32, list_array.value_type());
735        assert_eq!(2, list_array.len());
736        assert_eq!(0, list_array.null_count());
737        assert_eq!(6, list_array.value_offsets()[1]);
738        assert_eq!(2, list_array.value_length(1));
739        assert_eq!(3, list_array.value(0).as_primitive::<Int32Type>().value(0));
740        assert_eq!(
741            3,
742            unsafe { list_array.value_unchecked(0) }
743                .as_primitive::<Int32Type>()
744                .value(0)
745        );
746    }
747
748    #[test]
749    fn test_list_array_slice() {
750        // Construct a value array
751        let value_data = ArrayData::builder(DataType::Int32)
752            .len(10)
753            .add_buffer(Buffer::from_slice_ref([0, 1, 2, 3, 4, 5, 6, 7, 8, 9]))
754            .build()
755            .unwrap();
756
757        // Construct a buffer for value offsets, for the nested array:
758        //  [[0, 1], null, null, [2, 3], [4, 5], null, [6, 7, 8], null, [9]]
759        let value_offsets = Buffer::from_slice_ref([0, 2, 2, 2, 4, 6, 6, 9, 9, 10]);
760        // 01011001 00000001
761        let mut null_bits: [u8; 2] = [0; 2];
762        bit_util::set_bit(&mut null_bits, 0);
763        bit_util::set_bit(&mut null_bits, 3);
764        bit_util::set_bit(&mut null_bits, 4);
765        bit_util::set_bit(&mut null_bits, 6);
766        bit_util::set_bit(&mut null_bits, 8);
767
768        // Construct a list array from the above two
769        let list_data_type = DataType::List(Arc::new(Field::new("item", DataType::Int32, false)));
770        let list_data = ArrayData::builder(list_data_type)
771            .len(9)
772            .add_buffer(value_offsets)
773            .add_child_data(value_data.clone())
774            .null_bit_buffer(Some(Buffer::from(null_bits)))
775            .build()
776            .unwrap();
777        let list_array = ListArray::from(list_data);
778
779        let values = list_array.values();
780        assert_eq!(value_data, values.to_data());
781        assert_eq!(DataType::Int32, list_array.value_type());
782        assert_eq!(9, list_array.len());
783        assert_eq!(4, list_array.null_count());
784        assert_eq!(2, list_array.value_offsets()[3]);
785        assert_eq!(2, list_array.value_length(3));
786
787        let sliced_array = list_array.slice(1, 6);
788        assert_eq!(6, sliced_array.len());
789        assert_eq!(3, sliced_array.null_count());
790
791        for i in 0..sliced_array.len() {
792            if bit_util::get_bit(&null_bits, 1 + i) {
793                assert!(sliced_array.is_valid(i));
794            } else {
795                assert!(sliced_array.is_null(i));
796            }
797        }
798
799        // Check offset and length for each non-null value.
800        let sliced_list_array = sliced_array.as_any().downcast_ref::<ListArray>().unwrap();
801        assert_eq!(2, sliced_list_array.value_offsets()[2]);
802        assert_eq!(2, sliced_list_array.value_length(2));
803        assert_eq!(4, sliced_list_array.value_offsets()[3]);
804        assert_eq!(2, sliced_list_array.value_length(3));
805        assert_eq!(6, sliced_list_array.value_offsets()[5]);
806        assert_eq!(3, sliced_list_array.value_length(5));
807    }
808
809    #[test]
810    fn test_large_list_array_slice() {
811        // Construct a value array
812        let value_data = ArrayData::builder(DataType::Int32)
813            .len(10)
814            .add_buffer(Buffer::from_slice_ref([0, 1, 2, 3, 4, 5, 6, 7, 8, 9]))
815            .build()
816            .unwrap();
817
818        // Construct a buffer for value offsets, for the nested array:
819        //  [[0, 1], null, null, [2, 3], [4, 5], null, [6, 7, 8], null, [9]]
820        let value_offsets = Buffer::from_slice_ref([0i64, 2, 2, 2, 4, 6, 6, 9, 9, 10]);
821        // 01011001 00000001
822        let mut null_bits: [u8; 2] = [0; 2];
823        bit_util::set_bit(&mut null_bits, 0);
824        bit_util::set_bit(&mut null_bits, 3);
825        bit_util::set_bit(&mut null_bits, 4);
826        bit_util::set_bit(&mut null_bits, 6);
827        bit_util::set_bit(&mut null_bits, 8);
828
829        // Construct a list array from the above two
830        let list_data_type = DataType::new_large_list(DataType::Int32, false);
831        let list_data = ArrayData::builder(list_data_type)
832            .len(9)
833            .add_buffer(value_offsets)
834            .add_child_data(value_data.clone())
835            .null_bit_buffer(Some(Buffer::from(null_bits)))
836            .build()
837            .unwrap();
838        let list_array = LargeListArray::from(list_data);
839
840        let values = list_array.values();
841        assert_eq!(value_data, values.to_data());
842        assert_eq!(DataType::Int32, list_array.value_type());
843        assert_eq!(9, list_array.len());
844        assert_eq!(4, list_array.null_count());
845        assert_eq!(2, list_array.value_offsets()[3]);
846        assert_eq!(2, list_array.value_length(3));
847
848        let sliced_array = list_array.slice(1, 6);
849        assert_eq!(6, sliced_array.len());
850        assert_eq!(3, sliced_array.null_count());
851
852        for i in 0..sliced_array.len() {
853            if bit_util::get_bit(&null_bits, 1 + i) {
854                assert!(sliced_array.is_valid(i));
855            } else {
856                assert!(sliced_array.is_null(i));
857            }
858        }
859
860        // Check offset and length for each non-null value.
861        let sliced_list_array = sliced_array
862            .as_any()
863            .downcast_ref::<LargeListArray>()
864            .unwrap();
865        assert_eq!(2, sliced_list_array.value_offsets()[2]);
866        assert_eq!(2, sliced_list_array.value_length(2));
867        assert_eq!(4, sliced_list_array.value_offsets()[3]);
868        assert_eq!(2, sliced_list_array.value_length(3));
869        assert_eq!(6, sliced_list_array.value_offsets()[5]);
870        assert_eq!(3, sliced_list_array.value_length(5));
871    }
872
873    #[test]
874    #[should_panic(expected = "index out of bounds: the len is 10 but the index is 11")]
875    fn test_list_array_index_out_of_bound() {
876        // Construct a value array
877        let value_data = ArrayData::builder(DataType::Int32)
878            .len(10)
879            .add_buffer(Buffer::from_slice_ref([0, 1, 2, 3, 4, 5, 6, 7, 8, 9]))
880            .build()
881            .unwrap();
882
883        // Construct a buffer for value offsets, for the nested array:
884        //  [[0, 1], null, null, [2, 3], [4, 5], null, [6, 7, 8], null, [9]]
885        let value_offsets = Buffer::from_slice_ref([0i64, 2, 2, 2, 4, 6, 6, 9, 9, 10]);
886        // 01011001 00000001
887        let mut null_bits: [u8; 2] = [0; 2];
888        bit_util::set_bit(&mut null_bits, 0);
889        bit_util::set_bit(&mut null_bits, 3);
890        bit_util::set_bit(&mut null_bits, 4);
891        bit_util::set_bit(&mut null_bits, 6);
892        bit_util::set_bit(&mut null_bits, 8);
893
894        // Construct a list array from the above two
895        let list_data_type = DataType::new_large_list(DataType::Int32, false);
896        let list_data = ArrayData::builder(list_data_type)
897            .len(9)
898            .add_buffer(value_offsets)
899            .add_child_data(value_data)
900            .null_bit_buffer(Some(Buffer::from(null_bits)))
901            .build()
902            .unwrap();
903        let list_array = LargeListArray::from(list_data);
904        assert_eq!(9, list_array.len());
905
906        list_array.value(10);
907    }
908    #[test]
909    #[should_panic(expected = "ListArray data should contain a single buffer only (value offsets)")]
910    // Different error messages, so skip for now
911    // https://github.com/apache/arrow-rs/issues/1545
912    #[cfg(not(feature = "force_validate"))]
913    fn test_list_array_invalid_buffer_len() {
914        let value_data = unsafe {
915            ArrayData::builder(DataType::Int32)
916                .len(8)
917                .add_buffer(Buffer::from_slice_ref([0, 1, 2, 3, 4, 5, 6, 7]))
918                .build_unchecked()
919        };
920        let list_data_type = DataType::List(Arc::new(Field::new("item", DataType::Int32, false)));
921        let list_data = unsafe {
922            ArrayData::builder(list_data_type)
923                .len(3)
924                .add_child_data(value_data)
925                .build_unchecked()
926        };
927        drop(ListArray::from(list_data));
928    }
929
930    #[test]
931    #[should_panic(expected = "ListArray should contain a single child array (values array)")]
932    // Different error messages, so skip for now
933    // https://github.com/apache/arrow-rs/issues/1545
934    #[cfg(not(feature = "force_validate"))]
935    fn test_list_array_invalid_child_array_len() {
936        let value_offsets = Buffer::from_slice_ref([0, 2, 5, 7]);
937        let list_data_type = DataType::List(Arc::new(Field::new("item", DataType::Int32, false)));
938        let list_data = unsafe {
939            ArrayData::builder(list_data_type)
940                .len(3)
941                .add_buffer(value_offsets)
942                .build_unchecked()
943        };
944        drop(ListArray::from(list_data));
945    }
946
947    #[test]
948    #[should_panic(expected = "[Large]ListArray's datatype must be [Large]ListArray(). It is List")]
949    fn test_from_array_data_validation() {
950        let mut builder = ListBuilder::new(Int32Builder::new());
951        builder.values().append_value(1);
952        builder.append(true);
953        let array = builder.finish();
954        let _ = LargeListArray::from(array.into_data());
955    }
956
957    #[test]
958    fn test_list_array_offsets_need_not_start_at_zero() {
959        let value_data = ArrayData::builder(DataType::Int32)
960            .len(8)
961            .add_buffer(Buffer::from_slice_ref([0, 1, 2, 3, 4, 5, 6, 7]))
962            .build()
963            .unwrap();
964
965        let value_offsets = Buffer::from_slice_ref([2, 2, 5, 7]);
966
967        let list_data_type = DataType::List(Arc::new(Field::new("item", DataType::Int32, false)));
968        let list_data = ArrayData::builder(list_data_type)
969            .len(3)
970            .add_buffer(value_offsets)
971            .add_child_data(value_data)
972            .build()
973            .unwrap();
974
975        let list_array = ListArray::from(list_data);
976        assert_eq!(list_array.value_length(0), 0);
977        assert_eq!(list_array.value_length(1), 3);
978        assert_eq!(list_array.value_length(2), 2);
979    }
980
981    #[test]
982    #[should_panic(expected = "Memory pointer is not aligned with the specified scalar type")]
983    // Different error messages, so skip for now
984    // https://github.com/apache/arrow-rs/issues/1545
985    #[cfg(not(feature = "force_validate"))]
986    fn test_primitive_array_alignment() {
987        let buf = Buffer::from_slice_ref([0_u64]);
988        let buf2 = buf.slice(1);
989        let array_data = unsafe {
990            ArrayData::builder(DataType::Int32)
991                .add_buffer(buf2)
992                .build_unchecked()
993        };
994        drop(Int32Array::from(array_data));
995    }
996
997    #[test]
998    #[should_panic(expected = "Memory pointer is not aligned with the specified scalar type")]
999    // Different error messages, so skip for now
1000    // https://github.com/apache/arrow-rs/issues/1545
1001    #[cfg(not(feature = "force_validate"))]
1002    fn test_list_array_alignment() {
1003        let buf = Buffer::from_slice_ref([0_u64]);
1004        let buf2 = buf.slice(1);
1005
1006        let values: [i32; 8] = [0; 8];
1007        let value_data = unsafe {
1008            ArrayData::builder(DataType::Int32)
1009                .add_buffer(Buffer::from_slice_ref(values))
1010                .build_unchecked()
1011        };
1012
1013        let list_data_type = DataType::List(Arc::new(Field::new("item", DataType::Int32, false)));
1014        let list_data = unsafe {
1015            ArrayData::builder(list_data_type)
1016                .add_buffer(buf2)
1017                .add_child_data(value_data)
1018                .build_unchecked()
1019        };
1020        drop(ListArray::from(list_data));
1021    }
1022
1023    #[test]
1024    fn list_array_equality() {
1025        // test scaffold
1026        fn do_comparison(
1027            lhs_data: Vec<Option<Vec<Option<i32>>>>,
1028            rhs_data: Vec<Option<Vec<Option<i32>>>>,
1029            should_equal: bool,
1030        ) {
1031            let lhs = ListArray::from_iter_primitive::<Int32Type, _, _>(lhs_data.clone());
1032            let rhs = ListArray::from_iter_primitive::<Int32Type, _, _>(rhs_data.clone());
1033            assert_eq!(lhs == rhs, should_equal);
1034
1035            let lhs = LargeListArray::from_iter_primitive::<Int32Type, _, _>(lhs_data);
1036            let rhs = LargeListArray::from_iter_primitive::<Int32Type, _, _>(rhs_data);
1037            assert_eq!(lhs == rhs, should_equal);
1038        }
1039
1040        do_comparison(
1041            vec![
1042                Some(vec![Some(0), Some(1), Some(2)]),
1043                None,
1044                Some(vec![Some(3), None, Some(5)]),
1045                Some(vec![Some(6), Some(7)]),
1046            ],
1047            vec![
1048                Some(vec![Some(0), Some(1), Some(2)]),
1049                None,
1050                Some(vec![Some(3), None, Some(5)]),
1051                Some(vec![Some(6), Some(7)]),
1052            ],
1053            true,
1054        );
1055
1056        do_comparison(
1057            vec![
1058                None,
1059                None,
1060                Some(vec![Some(3), None, Some(5)]),
1061                Some(vec![Some(6), Some(7)]),
1062            ],
1063            vec![
1064                Some(vec![Some(0), Some(1), Some(2)]),
1065                None,
1066                Some(vec![Some(3), None, Some(5)]),
1067                Some(vec![Some(6), Some(7)]),
1068            ],
1069            false,
1070        );
1071
1072        do_comparison(
1073            vec![
1074                None,
1075                None,
1076                Some(vec![Some(3), None, Some(5)]),
1077                Some(vec![Some(6), Some(7)]),
1078            ],
1079            vec![
1080                None,
1081                None,
1082                Some(vec![Some(3), None, Some(5)]),
1083                Some(vec![Some(0), Some(0)]),
1084            ],
1085            false,
1086        );
1087
1088        do_comparison(
1089            vec![None, None, Some(vec![Some(1)])],
1090            vec![None, None, Some(vec![Some(2)])],
1091            false,
1092        );
1093    }
1094
1095    #[test]
1096    fn test_empty_offsets() {
1097        let f = Arc::new(Field::new("element", DataType::Int32, true));
1098        let string = ListArray::from(
1099            ArrayData::builder(DataType::List(f.clone()))
1100                .buffers(vec![Buffer::from(&[])])
1101                .add_child_data(ArrayData::new_empty(&DataType::Int32))
1102                .build()
1103                .unwrap(),
1104        );
1105        assert_eq!(string.value_offsets(), &[0]);
1106        let string = LargeListArray::from(
1107            ArrayData::builder(DataType::LargeList(f))
1108                .buffers(vec![Buffer::from(&[])])
1109                .add_child_data(ArrayData::new_empty(&DataType::Int32))
1110                .build()
1111                .unwrap(),
1112        );
1113        assert_eq!(string.len(), 0);
1114        assert_eq!(string.value_offsets(), &[0]);
1115    }
1116
1117    #[test]
1118    fn test_try_new() {
1119        let offsets = OffsetBuffer::new(vec![0, 1, 4, 5].into());
1120        let values = Int32Array::new(vec![1, 2, 3, 4, 5].into(), None);
1121        let values = Arc::new(values) as ArrayRef;
1122
1123        let field = Arc::new(Field::new("element", DataType::Int32, false));
1124        ListArray::new(field.clone(), offsets.clone(), values.clone(), None);
1125
1126        let nulls = NullBuffer::new_null(3);
1127        ListArray::new(field.clone(), offsets, values.clone(), Some(nulls));
1128
1129        let nulls = NullBuffer::new_null(3);
1130        let offsets = OffsetBuffer::new(vec![0, 1, 2, 4, 5].into());
1131        let err = LargeListArray::try_new(field, offsets.clone(), values.clone(), Some(nulls))
1132            .unwrap_err();
1133
1134        assert_eq!(
1135            err.to_string(),
1136            "Invalid argument error: Incorrect length of null buffer for LargeListArray, expected 4 got 3"
1137        );
1138
1139        let field = Arc::new(Field::new("element", DataType::Int64, false));
1140        let err = LargeListArray::try_new(field.clone(), offsets.clone(), values.clone(), None)
1141            .unwrap_err();
1142
1143        assert_eq!(
1144            err.to_string(),
1145            "Invalid argument error: LargeListArray expected data type Int64 got Int32 for \"element\""
1146        );
1147
1148        let nulls = NullBuffer::new_null(7);
1149        let values = Int64Array::new(vec![0; 7].into(), Some(nulls));
1150        let values = Arc::new(values);
1151
1152        let err =
1153            LargeListArray::try_new(field, offsets.clone(), values.clone(), None).unwrap_err();
1154
1155        assert_eq!(
1156            err.to_string(),
1157            "Invalid argument error: Non-nullable field of LargeListArray \"element\" cannot contain nulls"
1158        );
1159
1160        let field = Arc::new(Field::new("element", DataType::Int64, true));
1161        LargeListArray::new(field.clone(), offsets.clone(), values, None);
1162
1163        let values = Int64Array::new(vec![0; 2].into(), None);
1164        let err = LargeListArray::try_new(field, offsets, Arc::new(values), None).unwrap_err();
1165
1166        assert_eq!(
1167            err.to_string(),
1168            "Invalid argument error: Max offset of 5 exceeds length of values 2"
1169        );
1170    }
1171
1172    #[test]
1173    fn test_from_fixed_size_list() {
1174        let mut builder = FixedSizeListBuilder::new(Int32Builder::new(), 3);
1175        builder.values().append_slice(&[1, 2, 3]);
1176        builder.append(true);
1177        builder.values().append_slice(&[0, 0, 0]);
1178        builder.append(false);
1179        builder.values().append_slice(&[4, 5, 6]);
1180        builder.append(true);
1181        let list: ListArray = builder.finish().into();
1182
1183        let values: Vec<_> = list
1184            .iter()
1185            .map(|x| x.map(|x| x.as_primitive::<Int32Type>().values().to_vec()))
1186            .collect();
1187        assert_eq!(values, vec![Some(vec![1, 2, 3]), None, Some(vec![4, 5, 6])])
1188    }
1189
1190    #[test]
1191    fn test_nullable_union() {
1192        let offsets = OffsetBuffer::new(vec![0, 1, 4, 5].into());
1193        let mut builder = UnionBuilder::new_dense();
1194        builder.append::<Int32Type>("a", 1).unwrap();
1195        builder.append::<Int32Type>("b", 2).unwrap();
1196        builder.append::<Int32Type>("b", 3).unwrap();
1197        builder.append::<Int32Type>("a", 4).unwrap();
1198        builder.append::<Int32Type>("a", 5).unwrap();
1199        let values = builder.build().unwrap();
1200        let field = Arc::new(Field::new("element", values.data_type().clone(), false));
1201        ListArray::new(field.clone(), offsets, Arc::new(values), None);
1202    }
1203}
arrow_array/array/list_array.rs

arrow_array/array/
list_array.rs
