arrow_array/array/
list_array.rs

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_from_buffer, make_array, print_long_array};
19use crate::builder::{ArrayBuilder, GenericListBuilder, PrimitiveBuilder};
20use crate::{
21    Array, ArrayAccessor, ArrayRef, ArrowPrimitiveType, FixedSizeListArray,
22    iterator::GenericListArrayIter, new_empty_array,
23};
24use arrow_buffer::{ArrowNativeType, NullBuffer, OffsetBuffer};
25use arrow_data::{ArrayData, ArrayDataBuilder};
26use arrow_schema::{ArrowError, DataType, FieldRef};
27use num_integer::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:
41    ArrowNativeType + std::ops::AddAssign + Integer + num_traits::CheckedAdd
42{
43    /// True for 64 bit offset size and false for 32 bit offset size
44    const IS_LARGE: bool;
45    /// Prefix for the offset size
46    const PREFIX: &'static str;
47    /// The max `usize` offset
48    const MAX_OFFSET: usize;
49}
50
51impl OffsetSizeTrait for i32 {
52    const IS_LARGE: bool = false;
53    const PREFIX: &'static str = "";
54    const MAX_OFFSET: usize = i32::MAX as usize;
55}
56
57impl OffsetSizeTrait for i64 {
58    const IS_LARGE: bool = true;
59    const PREFIX: &'static str = "Large";
60    const MAX_OFFSET: usize = i64::MAX as usize;
61}
62
63/// An array of [variable length lists], similar to JSON arrays
64/// (e.g. `["A", "B", "C"]`). This struct specifically represents
65/// the [list layout]. Refer to [`GenericListViewArray`] for the
66/// [list-view layout].
67///
68/// Lists are represented using `offsets` into a `values` child
69/// array. Offsets are stored in two adjacent entries of an
70/// [`OffsetBuffer`].
71///
72/// Arrow defines [`ListArray`] with `i32` offsets and
73/// [`LargeListArray`] with `i64` offsets.
74///
75/// Use [`GenericListBuilder`] to construct a [`GenericListArray`].
76///
77/// # Representation
78///
79/// A [`ListArray`] can represent a list of values of any other
80/// supported Arrow type. Each element of the `ListArray` itself is
81/// a list which may be empty, may contain NULL and non-null values,
82/// or may itself be NULL.
83///
84/// For example, the `ListArray` shown in the following diagram stores
85/// lists of strings. Note that `[]` represents an empty (length
86/// 0), but non NULL list.
87///
88/// ```text
89/// ┌─────────────┐
90/// │   [A,B,C]   │
91/// ├─────────────┤
92/// │     []      │
93/// ├─────────────┤
94/// │    NULL     │
95/// ├─────────────┤
96/// │     [D]     │
97/// ├─────────────┤
98/// │  [NULL, F]  │
99/// └─────────────┘
100/// ```
101///
102/// The `values` are stored in a child [`StringArray`] and the offsets
103/// are stored in an [`OffsetBuffer`] as shown in the following
104/// diagram. The logical values and offsets are shown on the left, and
105/// the actual `ListArray` encoding on the right.
106///
107/// ```text
108///                                         ┌ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─
109///                                                                 ┌ ─ ─ ─ ─ ─ ─ ┐    │
110///  ┌─────────────┐  ┌───────┐             │     ┌───┐   ┌───┐       ┌───┐ ┌───┐
111///  │   [A,B,C]   │  │ (0,3) │                   │ 1 │   │ 0 │     │ │ 1 │ │ A │ │ 0  │
112///  ├─────────────┤  ├───────┤             │     ├───┤   ├───┤       ├───┤ ├───┤
113///  │ [] (empty)  │  │ (3,3) │                   │ 1 │   │ 3 │     │ │ 1 │ │ B │ │ 1  │
114///  ├─────────────┤  ├───────┤             │     ├───┤   ├───┤       ├───┤ ├───┤
115///  │    NULL     │  │ (3,3) │                   │ 0 │   │ 3 │     │ │ 1 │ │ C │ │ 2  │
116///  ├─────────────┤  ├───────┤             │     ├───┤   ├───┤       ├───┤ ├───┤
117///  │     [D]     │  │ (3,4) │                   │ 1 │   │ 3 │     │ │ 1 │ │ D │ │ 3  │
118///  ├─────────────┤  ├───────┤             │     ├───┤   ├───┤       ├───┤ ├───┤
119///  │  [NULL, F]  │  │ (4,6) │                   │ 1 │   │ 4 │     │ │ 0 │ │ ? │ │ 4  │
120///  └─────────────┘  └───────┘             │     └───┘   ├───┤       ├───┤ ├───┤
121///                                                       │ 6 │     │ │ 1 │ │ F │ │ 5  │
122///                                         │  Validity   └───┘       └───┘ └───┘
123///     Logical       Logical                  (nulls)   Offsets    │    Values   │    │
124///      Values       Offsets               │                           (Array)
125///                                                                 └ ─ ─ ─ ─ ─ ─ ┘    │
126///                 (offsets[i],            │   ListArray
127///                offsets[i+1])                                                       │
128///                                         └ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─
129/// ```
130///
131/// # Slicing
132///
133/// Slicing a `ListArray` creates a new `ListArray` without copying any data,
134/// but this means the [`Self::values`] and [`Self::offsets`] may have "unused" data
135///
136/// For example, calling `slice(1, 3)` on the `ListArray` in the above example
137/// would result in the following. Note
138///
139/// 1. `Values` array is unchanged
140/// 2. `Offsets` do not start at `0`, nor cover all values in the Values array.
141///
142/// ```text
143///                                 ┌ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─
144///                                                         ┌ ─ ─ ─ ─ ─ ─ ┐    │  ╔═══╗
145///                                 │                         ╔═══╗ ╔═══╗         ║   ║  Not used
146///                                                         │ ║ 1 ║ ║ A ║ │ 0  │  ╚═══╝
147///  ┌─────────────┐  ┌───────┐     │     ┌───┐   ┌───┐       ╠═══╣ ╠═══╣
148///  │ [] (empty)  │  │ (3,3) │           │ 1 │   │ 3 │     │ ║ 1 ║ ║ B ║ │ 1  │
149///  ├─────────────┤  ├───────┤     │     ├───┤   ├───┤       ╠═══╣ ╠═══╣
150///  │    NULL     │  │ (3,3) │           │ 0 │   │ 3 │     │ ║ 1 ║ ║ C ║ │ 2  │
151///  ├─────────────┤  ├───────┤     │     ├───┤   ├───┤       ╚═══╝ ╚═══╝
152///  │     [D]     │  │ (3,4) │           │ 1 │   │ 3 │     │ │ 1 │ │ D │ │ 3  │
153///  └─────────────┘  └───────┘     │     └───┘   ├───┤       ╔═══╗ ╔═══╗
154///                                               │ 4 │     │ ║ 0 ║ ║ ? ║ │ 4  │
155///                                 │             └───┘       ╠═══╣ ╠═══╣
156///                                                         │ ║ 1 ║ ║ F ║ │ 5  │
157///                                 │  Validity               ╚═══╝ ╚═══╝
158///     Logical       Logical          (nulls)   Offsets    │    Values   │    │
159///      Values       Offsets       │                           (Array)
160///                                                         └ ─ ─ ─ ─ ─ ─ ┘    │
161///                 (offsets[i],    │   ListArray
162///                offsets[i+1])                                               │
163///                                 └ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─
164/// ```
165///
166/// [`StringArray`]: crate::array::StringArray
167/// [`GenericListViewArray`]: crate::array::GenericListViewArray
168/// [variable length lists]: https://arrow.apache.org/docs/format/Columnar.html#variable-size-list-layout
169/// [list layout]: https://arrow.apache.org/docs/format/Columnar.html#list-layout
170/// [list-view layout]: https://arrow.apache.org/docs/format/Columnar.html#listview-layout
171pub struct GenericListArray<OffsetSize: OffsetSizeTrait> {
172    data_type: DataType,
173    nulls: Option<NullBuffer>,
174    values: ArrayRef,
175    value_offsets: OffsetBuffer<OffsetSize>,
176}
177
178impl<OffsetSize: OffsetSizeTrait> Clone for GenericListArray<OffsetSize> {
179    fn clone(&self) -> Self {
180        Self {
181            data_type: self.data_type.clone(),
182            nulls: self.nulls.clone(),
183            values: self.values.clone(),
184            value_offsets: self.value_offsets.clone(),
185        }
186    }
187}
188
189impl<OffsetSize: OffsetSizeTrait> GenericListArray<OffsetSize> {
190    /// The data type constructor of list array.
191    /// The input is the schema of the child array and
192    /// the output is the [`DataType`], List or LargeList.
193    pub const DATA_TYPE_CONSTRUCTOR: fn(FieldRef) -> DataType = if OffsetSize::IS_LARGE {
194        DataType::LargeList
195    } else {
196        DataType::List
197    };
198
199    /// Create a new [`GenericListArray`] from the provided parts
200    ///
201    /// # Errors
202    ///
203    /// Errors if
204    ///
205    /// * `offsets.len() - 1 != nulls.len()`
206    /// * `offsets.last() > values.len()`
207    /// * `!field.is_nullable() && values.is_nullable()`
208    /// * `field.data_type() != values.data_type()`
209    pub fn try_new(
210        field: FieldRef,
211        offsets: OffsetBuffer<OffsetSize>,
212        values: ArrayRef,
213        nulls: Option<NullBuffer>,
214    ) -> Result<Self, ArrowError> {
215        let len = offsets.len() - 1; // Offsets guaranteed to not be empty
216        let end_offset = offsets.last().unwrap().as_usize();
217        // don't need to check other values of `offsets` because they are checked
218        // during construction of `OffsetBuffer`
219        if end_offset > values.len() {
220            return Err(ArrowError::InvalidArgumentError(format!(
221                "Max offset of {end_offset} exceeds length of values {}",
222                values.len()
223            )));
224        }
225
226        if let Some(n) = nulls.as_ref() {
227            if n.len() != len {
228                return Err(ArrowError::InvalidArgumentError(format!(
229                    "Incorrect length of null buffer for {}ListArray, expected {len} got {}",
230                    OffsetSize::PREFIX,
231                    n.len(),
232                )));
233            }
234        }
235        if !field.is_nullable() && values.is_nullable() {
236            return Err(ArrowError::InvalidArgumentError(format!(
237                "Non-nullable field of {}ListArray {:?} cannot contain nulls",
238                OffsetSize::PREFIX,
239                field.name()
240            )));
241        }
242
243        if field.data_type() != values.data_type() {
244            return Err(ArrowError::InvalidArgumentError(format!(
245                "{}ListArray expected data type {} got {} for {:?}",
246                OffsetSize::PREFIX,
247                field.data_type(),
248                values.data_type(),
249                field.name()
250            )));
251        }
252
253        Ok(Self {
254            data_type: Self::DATA_TYPE_CONSTRUCTOR(field),
255            nulls,
256            values,
257            value_offsets: offsets,
258        })
259    }
260
261    /// Create a new [`GenericListArray`] from the provided parts
262    ///
263    /// # Panics
264    ///
265    /// Panics if [`Self::try_new`] returns an error
266    pub fn new(
267        field: FieldRef,
268        offsets: OffsetBuffer<OffsetSize>,
269        values: ArrayRef,
270        nulls: Option<NullBuffer>,
271    ) -> Self {
272        Self::try_new(field, offsets, values, nulls).unwrap()
273    }
274
275    /// Create a new [`GenericListArray`] of length `len` where all values are null
276    pub fn new_null(field: FieldRef, len: usize) -> Self {
277        let values = new_empty_array(field.data_type());
278        Self {
279            data_type: Self::DATA_TYPE_CONSTRUCTOR(field),
280            nulls: Some(NullBuffer::new_null(len)),
281            value_offsets: OffsetBuffer::new_zeroed(len),
282            values,
283        }
284    }
285
286    /// Deconstruct this array into its constituent parts
287    pub fn into_parts(
288        self,
289    ) -> (
290        FieldRef,
291        OffsetBuffer<OffsetSize>,
292        ArrayRef,
293        Option<NullBuffer>,
294    ) {
295        let f = match self.data_type {
296            DataType::List(f) | DataType::LargeList(f) => f,
297            _ => unreachable!(),
298        };
299        (f, self.value_offsets, self.values, self.nulls)
300    }
301
302    /// Returns a reference to the offsets of this list
303    ///
304    /// Unlike [`Self::value_offsets`] this returns the [`OffsetBuffer`]
305    /// allowing for zero-copy cloning.
306    ///
307    /// Notes: The `offsets` may not start at 0 and may not cover all values in
308    /// [`Self::values`]. This can happen when the list array was sliced via
309    /// [`Self::slice`]. See documentation for [`Self`] for more details.
310    #[inline]
311    pub fn offsets(&self) -> &OffsetBuffer<OffsetSize> {
312        &self.value_offsets
313    }
314
315    /// Returns a reference to the values of this list
316    ///
317    /// Note: The list array may not refer to all values in the `values` array.
318    /// For example if the list array was sliced via [`Self::slice`] values will
319    /// still contain values both before and after the slice. See documentation
320    /// for [`Self`] for more details.
321    #[inline]
322    pub fn values(&self) -> &ArrayRef {
323        &self.values
324    }
325
326    /// Returns a clone of the value type of this list.
327    pub fn value_type(&self) -> DataType {
328        self.values.data_type().clone()
329    }
330
331    /// Returns ith value of this list array.
332    ///
333    /// Note: This method does not check for nulls and the value is arbitrary
334    /// if [`is_null`](Self::is_null) returns true for the index.
335    ///
336    /// # Safety
337    /// Caller must ensure that the index is within the array bounds
338    pub unsafe fn value_unchecked(&self, i: usize) -> ArrayRef {
339        let end = unsafe { self.value_offsets().get_unchecked(i + 1).as_usize() };
340        let start = unsafe { self.value_offsets().get_unchecked(i).as_usize() };
341        self.values.slice(start, end - start)
342    }
343
344    /// Returns ith value of this list array.
345    ///
346    /// Note: This method does not check for nulls and the value is arbitrary
347    /// (but still well-defined) if [`is_null`](Self::is_null) returns true for the index.
348    ///
349    /// # Panics
350    /// Panics if index `i` is out of bounds
351    pub fn value(&self, i: usize) -> ArrayRef {
352        let end = self.value_offsets()[i + 1].as_usize();
353        let start = self.value_offsets()[i].as_usize();
354        self.values.slice(start, end - start)
355    }
356
357    /// Returns the offset values in the offsets buffer.
358    ///
359    /// See [`Self::offsets`] for more details.
360    #[inline]
361    pub fn value_offsets(&self) -> &[OffsetSize] {
362        &self.value_offsets
363    }
364
365    /// Returns the length for value at index `i`.
366    #[inline]
367    pub fn value_length(&self, i: usize) -> OffsetSize {
368        let offsets = self.value_offsets();
369        offsets[i + 1] - offsets[i]
370    }
371
372    /// constructs a new iterator
373    pub fn iter<'a>(&'a self) -> GenericListArrayIter<'a, OffsetSize> {
374        GenericListArrayIter::<'a, OffsetSize>::new(self)
375    }
376
377    #[inline]
378    fn get_type(data_type: &DataType) -> Option<&DataType> {
379        match (OffsetSize::IS_LARGE, data_type) {
380            (true, DataType::LargeList(child)) | (false, DataType::List(child)) => {
381                Some(child.data_type())
382            }
383            _ => None,
384        }
385    }
386
387    /// Returns a zero-copy slice of this array with the indicated offset and length.
388    ///
389    /// Notes: this method does *NOT* slice the underlying values array or modify
390    /// the values in the offsets buffer. See [`Self::values`] and
391    /// [`Self::offsets`] for more information.
392    pub fn slice(&self, offset: usize, length: usize) -> Self {
393        Self {
394            data_type: self.data_type.clone(),
395            nulls: self.nulls.as_ref().map(|n| n.slice(offset, length)),
396            values: self.values.clone(),
397            value_offsets: self.value_offsets.slice(offset, length),
398        }
399    }
400
401    /// Creates a [`GenericListArray`] from an iterator of primitive values
402    /// # Example
403    /// ```
404    /// # use arrow_array::ListArray;
405    /// # use arrow_array::types::Int32Type;
406    ///
407    /// let data = vec![
408    ///    Some(vec![Some(0), Some(1), Some(2)]),
409    ///    None,
410    ///    Some(vec![Some(3), None, Some(5)]),
411    ///    Some(vec![Some(6), Some(7)]),
412    /// ];
413    /// let list_array = ListArray::from_iter_primitive::<Int32Type, _, _>(data);
414    /// println!("{:?}", list_array);
415    /// ```
416    pub fn from_iter_primitive<T, P, I>(iter: I) -> Self
417    where
418        T: ArrowPrimitiveType,
419        P: IntoIterator<Item = Option<<T as ArrowPrimitiveType>::Native>>,
420        I: IntoIterator<Item = Option<P>>,
421    {
422        Self::from_nested_iter::<PrimitiveBuilder<T>, T::Native, P, I>(iter)
423    }
424
425    /// Creates a [`GenericListArray`] from a nested iterator of values.
426    /// This method works for any values type that has a corresponding builder that implements the
427    /// `Extend` trait. That includes all numeric types, booleans, binary and string types and also
428    /// dictionary encoded binary and strings.
429    ///
430    /// # Example
431    /// ```
432    /// # use arrow_array::ListArray;
433    /// # use arrow_array::types::Int32Type;
434    /// # use arrow_array::builder::StringDictionaryBuilder;
435    /// let data = vec![
436    ///    Some(vec![Some("foo"), Some("bar"), Some("baz")]),
437    ///    None,
438    ///    Some(vec![Some("bar"), None, Some("foo")]),
439    ///    Some(vec![]),
440    /// ];
441    /// let list_array = ListArray::from_nested_iter::<StringDictionaryBuilder<Int32Type>, _, _, _>(data);
442    /// println!("{:?}", list_array);
443    /// ```
444    pub fn from_nested_iter<B, T, P, I>(iter: I) -> Self
445    where
446        B: ArrayBuilder + Default + Extend<Option<T>>,
447        P: IntoIterator<Item = Option<T>>,
448        I: IntoIterator<Item = Option<P>>,
449    {
450        let iter = iter.into_iter();
451        let size_hint = iter.size_hint().0;
452        let mut builder = GenericListBuilder::with_capacity(B::default(), size_hint);
453
454        for i in iter {
455            match i {
456                Some(p) => {
457                    builder.values().extend(p);
458                    builder.append(true);
459                }
460                None => builder.append(false),
461            }
462        }
463        builder.finish()
464    }
465}
466
467impl<OffsetSize: OffsetSizeTrait> From<ArrayData> for GenericListArray<OffsetSize> {
468    fn from(data: ArrayData) -> Self {
469        Self::try_new_from_array_data(data)
470            .expect("Expected infallible creation of GenericListArray from ArrayDataRef failed")
471    }
472}
473
474impl<OffsetSize: OffsetSizeTrait> From<GenericListArray<OffsetSize>> for ArrayData {
475    fn from(array: GenericListArray<OffsetSize>) -> Self {
476        let len = array.len();
477        let builder = ArrayDataBuilder::new(array.data_type)
478            .len(len)
479            .nulls(array.nulls)
480            .buffers(vec![array.value_offsets.into_inner().into_inner()])
481            .child_data(vec![array.values.to_data()]);
482
483        unsafe { builder.build_unchecked() }
484    }
485}
486
487impl<OffsetSize: OffsetSizeTrait> From<FixedSizeListArray> for GenericListArray<OffsetSize> {
488    fn from(value: FixedSizeListArray) -> Self {
489        let (field, size) = match value.data_type() {
490            DataType::FixedSizeList(f, size) => (f, *size as usize),
491            _ => unreachable!(),
492        };
493
494        let offsets = OffsetBuffer::from_repeated_length(size, value.len());
495
496        Self {
497            data_type: Self::DATA_TYPE_CONSTRUCTOR(field.clone()),
498            nulls: value.nulls().cloned(),
499            values: value.values().clone(),
500            value_offsets: offsets,
501        }
502    }
503}
504
505impl<OffsetSize: OffsetSizeTrait> GenericListArray<OffsetSize> {
506    fn try_new_from_array_data(data: ArrayData) -> Result<Self, ArrowError> {
507        let (data_type, len, nulls, offset, mut buffers, mut child_data) = data.into_parts();
508
509        if buffers.len() != 1 {
510            return Err(ArrowError::InvalidArgumentError(format!(
511                "ListArray data should contain a single buffer only (value offsets), had {}",
512                buffers.len()
513            )));
514        }
515        let buffer = buffers.pop().expect("checked above");
516
517        if child_data.len() != 1 {
518            return Err(ArrowError::InvalidArgumentError(format!(
519                "ListArray should contain a single child array (values array), had {}",
520                child_data.len()
521            )));
522        }
523
524        let values = child_data.pop().expect("checked above");
525
526        if let Some(child_data_type) = Self::get_type(&data_type) {
527            if values.data_type() != child_data_type {
528                return Err(ArrowError::InvalidArgumentError(format!(
529                    "[Large]ListArray's child datatype {:?} does not \
530                             correspond to the List's datatype {:?}",
531                    values.data_type(),
532                    child_data_type
533                )));
534            }
535        } else {
536            return Err(ArrowError::InvalidArgumentError(format!(
537                "[Large]ListArray's datatype must be [Large]ListArray(). It is {data_type:?}",
538            )));
539        }
540
541        let values = make_array(values);
542        // SAFETY:
543        // ArrayData is valid, and verified type above
544        let value_offsets = unsafe { get_offsets_from_buffer(buffer, offset, len) };
545
546        Ok(Self {
547            data_type,
548            nulls,
549            values,
550            value_offsets,
551        })
552    }
553}
554
555/// SAFETY: Correctly implements the contract of Arrow Arrays
556unsafe impl<OffsetSize: OffsetSizeTrait> Array for GenericListArray<OffsetSize> {
557    fn as_any(&self) -> &dyn Any {
558        self
559    }
560
561    fn to_data(&self) -> ArrayData {
562        self.clone().into()
563    }
564
565    fn into_data(self) -> ArrayData {
566        self.into()
567    }
568
569    fn data_type(&self) -> &DataType {
570        &self.data_type
571    }
572
573    fn slice(&self, offset: usize, length: usize) -> ArrayRef {
574        Arc::new(self.slice(offset, length))
575    }
576
577    fn len(&self) -> usize {
578        self.value_offsets.len() - 1
579    }
580
581    fn is_empty(&self) -> bool {
582        self.value_offsets.len() <= 1
583    }
584
585    fn shrink_to_fit(&mut self) {
586        if let Some(nulls) = &mut self.nulls {
587            nulls.shrink_to_fit();
588        }
589        self.values.shrink_to_fit();
590        self.value_offsets.shrink_to_fit();
591    }
592
593    fn offset(&self) -> usize {
594        0
595    }
596
597    fn nulls(&self) -> Option<&NullBuffer> {
598        self.nulls.as_ref()
599    }
600
601    fn logical_null_count(&self) -> usize {
602        // More efficient that the default implementation
603        self.null_count()
604    }
605
606    fn get_buffer_memory_size(&self) -> usize {
607        let mut size = self.values.get_buffer_memory_size();
608        size += self.value_offsets.inner().inner().capacity();
609        if let Some(n) = self.nulls.as_ref() {
610            size += n.buffer().capacity();
611        }
612        size
613    }
614
615    fn get_array_memory_size(&self) -> usize {
616        let mut size = std::mem::size_of::<Self>() + self.values.get_array_memory_size();
617        size += self.value_offsets.inner().inner().capacity();
618        if let Some(n) = self.nulls.as_ref() {
619            size += n.buffer().capacity();
620        }
621        size
622    }
623}
624
625impl<OffsetSize: OffsetSizeTrait> ArrayAccessor for &GenericListArray<OffsetSize> {
626    type Item = ArrayRef;
627
628    fn value(&self, index: usize) -> Self::Item {
629        GenericListArray::value(self, index)
630    }
631
632    unsafe fn value_unchecked(&self, index: usize) -> Self::Item {
633        GenericListArray::value(self, index)
634    }
635}
636
637impl<OffsetSize: OffsetSizeTrait> std::fmt::Debug for GenericListArray<OffsetSize> {
638    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
639        let prefix = OffsetSize::PREFIX;
640
641        write!(f, "{prefix}ListArray\n[\n")?;
642        print_long_array(self, f, |array, index, f| {
643            std::fmt::Debug::fmt(&array.value(index), f)
644        })?;
645        write!(f, "]")
646    }
647}
648
649/// A [`GenericListArray`] of variable size lists, storing offsets as `i32`.
650///
651/// See [`ListBuilder`](crate::builder::ListBuilder) for how to construct a [`ListArray`]
652pub type ListArray = GenericListArray<i32>;
653
654/// A [`GenericListArray`] of variable size lists, storing offsets as `i64`.
655///
656/// See [`LargeListBuilder`](crate::builder::LargeListBuilder) for how to construct a [`LargeListArray`]
657pub type LargeListArray = GenericListArray<i64>;
658
659#[cfg(test)]
660mod tests {
661    use super::*;
662    use crate::builder::{
663        BooleanBuilder, FixedSizeListBuilder, Int32Builder, ListBuilder, StringBuilder,
664        StringDictionaryBuilder, UnionBuilder,
665    };
666    use crate::cast::AsArray;
667    use crate::types::{Int8Type, Int32Type};
668    use crate::{
669        BooleanArray, Int8Array, Int8DictionaryArray, Int32Array, Int64Array, StringArray,
670    };
671    use arrow_buffer::{Buffer, ScalarBuffer, bit_util};
672    use arrow_schema::Field;
673
674    fn create_from_buffers() -> ListArray {
675        //  [[0, 1, 2], [3, 4, 5], [6, 7]]
676        let values = Int32Array::from(vec![0, 1, 2, 3, 4, 5, 6, 7]);
677        let offsets = OffsetBuffer::new(ScalarBuffer::from(vec![0, 3, 6, 8]));
678        let field = Arc::new(Field::new_list_field(DataType::Int32, true));
679        ListArray::new(field, offsets, Arc::new(values), None)
680    }
681
682    #[test]
683    fn test_from_iter_primitive() {
684        let data = vec![
685            Some(vec![Some(0), Some(1), Some(2)]),
686            Some(vec![Some(3), Some(4), Some(5)]),
687            Some(vec![Some(6), Some(7)]),
688        ];
689        let list_array = ListArray::from_iter_primitive::<Int32Type, _, _>(data);
690
691        let another = create_from_buffers();
692        assert_eq!(list_array, another)
693    }
694
695    #[test]
696    fn test_empty_list_array() {
697        // Construct an empty value array
698        let value_data = ArrayData::builder(DataType::Int32)
699            .len(0)
700            .add_buffer(Buffer::from([]))
701            .build()
702            .unwrap();
703
704        // Construct an empty offset buffer
705        let value_offsets = Buffer::from([]);
706
707        // Construct a list array from the above two
708        let list_data_type =
709            DataType::List(Arc::new(Field::new_list_field(DataType::Int32, false)));
710        let list_data = ArrayData::builder(list_data_type)
711            .len(0)
712            .add_buffer(value_offsets)
713            .add_child_data(value_data)
714            .build()
715            .unwrap();
716
717        let list_array = ListArray::from(list_data);
718        assert_eq!(list_array.len(), 0)
719    }
720
721    #[test]
722    fn test_list_array() {
723        // Construct a value array
724        let value_data = ArrayData::builder(DataType::Int32)
725            .len(8)
726            .add_buffer(Buffer::from_slice_ref([0, 1, 2, 3, 4, 5, 6, 7]))
727            .build()
728            .unwrap();
729
730        // Construct a buffer for value offsets, for the nested array:
731        //  [[0, 1, 2], [3, 4, 5], [6, 7]]
732        let value_offsets = Buffer::from_slice_ref([0, 3, 6, 8]);
733
734        // Construct a list array from the above two
735        let list_data_type =
736            DataType::List(Arc::new(Field::new_list_field(DataType::Int32, false)));
737        let list_data = ArrayData::builder(list_data_type.clone())
738            .len(3)
739            .add_buffer(value_offsets.clone())
740            .add_child_data(value_data.clone())
741            .build()
742            .unwrap();
743        let list_array = ListArray::from(list_data);
744
745        let values = list_array.values();
746        assert_eq!(value_data, values.to_data());
747        assert_eq!(DataType::Int32, list_array.value_type());
748        assert_eq!(3, list_array.len());
749        assert_eq!(0, list_array.null_count());
750        assert_eq!(6, list_array.value_offsets()[2]);
751        assert_eq!(2, list_array.value_length(2));
752        assert_eq!(0, list_array.value(0).as_primitive::<Int32Type>().value(0));
753        assert_eq!(
754            0,
755            unsafe { list_array.value_unchecked(0) }
756                .as_primitive::<Int32Type>()
757                .value(0)
758        );
759        for i in 0..3 {
760            assert!(list_array.is_valid(i));
761            assert!(!list_array.is_null(i));
762        }
763
764        // Now test with a non-zero offset (skip first element)
765        //  [[3, 4, 5], [6, 7]]
766        let list_data = ArrayData::builder(list_data_type)
767            .len(2)
768            .offset(1)
769            .add_buffer(value_offsets)
770            .add_child_data(value_data.clone())
771            .build()
772            .unwrap();
773        let list_array = ListArray::from(list_data);
774
775        let values = list_array.values();
776        assert_eq!(value_data, values.to_data());
777        assert_eq!(DataType::Int32, list_array.value_type());
778        assert_eq!(2, list_array.len());
779        assert_eq!(0, list_array.null_count());
780        assert_eq!(6, list_array.value_offsets()[1]);
781        assert_eq!(2, list_array.value_length(1));
782        assert_eq!(3, list_array.value(0).as_primitive::<Int32Type>().value(0));
783        assert_eq!(
784            3,
785            unsafe { list_array.value_unchecked(0) }
786                .as_primitive::<Int32Type>()
787                .value(0)
788        );
789    }
790
791    #[test]
792    fn test_large_list_array() {
793        // Construct a value array
794        let value_data = ArrayData::builder(DataType::Int32)
795            .len(8)
796            .add_buffer(Buffer::from_slice_ref([0, 1, 2, 3, 4, 5, 6, 7]))
797            .build()
798            .unwrap();
799
800        // Construct a buffer for value offsets, for the nested array:
801        //  [[0, 1, 2], [3, 4, 5], [6, 7]]
802        let value_offsets = Buffer::from_slice_ref([0i64, 3, 6, 8]);
803
804        // Construct a list array from the above two
805        let list_data_type = DataType::new_large_list(DataType::Int32, false);
806        let list_data = ArrayData::builder(list_data_type.clone())
807            .len(3)
808            .add_buffer(value_offsets.clone())
809            .add_child_data(value_data.clone())
810            .build()
811            .unwrap();
812        let list_array = LargeListArray::from(list_data);
813
814        let values = list_array.values();
815        assert_eq!(value_data, values.to_data());
816        assert_eq!(DataType::Int32, list_array.value_type());
817        assert_eq!(3, list_array.len());
818        assert_eq!(0, list_array.null_count());
819        assert_eq!(6, list_array.value_offsets()[2]);
820        assert_eq!(2, list_array.value_length(2));
821        assert_eq!(0, list_array.value(0).as_primitive::<Int32Type>().value(0));
822        assert_eq!(
823            0,
824            unsafe { list_array.value_unchecked(0) }
825                .as_primitive::<Int32Type>()
826                .value(0)
827        );
828        for i in 0..3 {
829            assert!(list_array.is_valid(i));
830            assert!(!list_array.is_null(i));
831        }
832
833        // Now test with a non-zero offset
834        //  [[3, 4, 5], [6, 7]]
835        let list_data = ArrayData::builder(list_data_type)
836            .len(2)
837            .offset(1)
838            .add_buffer(value_offsets)
839            .add_child_data(value_data.clone())
840            .build()
841            .unwrap();
842        let list_array = LargeListArray::from(list_data);
843
844        let values = list_array.values();
845        assert_eq!(value_data, values.to_data());
846        assert_eq!(DataType::Int32, list_array.value_type());
847        assert_eq!(2, list_array.len());
848        assert_eq!(0, list_array.null_count());
849        assert_eq!(6, list_array.value_offsets()[1]);
850        assert_eq!(2, list_array.value_length(1));
851        assert_eq!(3, list_array.value(0).as_primitive::<Int32Type>().value(0));
852        assert_eq!(
853            3,
854            unsafe { list_array.value_unchecked(0) }
855                .as_primitive::<Int32Type>()
856                .value(0)
857        );
858    }
859
860    #[test]
861    fn test_list_array_slice() {
862        // Construct a value array
863        let value_data = ArrayData::builder(DataType::Int32)
864            .len(10)
865            .add_buffer(Buffer::from_slice_ref([0, 1, 2, 3, 4, 5, 6, 7, 8, 9]))
866            .build()
867            .unwrap();
868
869        // Construct a buffer for value offsets, for the nested array:
870        //  [[0, 1], null, null, [2, 3], [4, 5], null, [6, 7, 8], null, [9]]
871        let value_offsets = Buffer::from_slice_ref([0, 2, 2, 2, 4, 6, 6, 9, 9, 10]);
872        // 01011001 00000001
873        let mut null_bits: [u8; 2] = [0; 2];
874        bit_util::set_bit(&mut null_bits, 0);
875        bit_util::set_bit(&mut null_bits, 3);
876        bit_util::set_bit(&mut null_bits, 4);
877        bit_util::set_bit(&mut null_bits, 6);
878        bit_util::set_bit(&mut null_bits, 8);
879
880        // Construct a list array from the above two
881        let list_data_type =
882            DataType::List(Arc::new(Field::new_list_field(DataType::Int32, false)));
883        let list_data = ArrayData::builder(list_data_type)
884            .len(9)
885            .add_buffer(value_offsets)
886            .add_child_data(value_data.clone())
887            .null_bit_buffer(Some(Buffer::from(null_bits)))
888            .build()
889            .unwrap();
890        let list_array = ListArray::from(list_data);
891
892        let values = list_array.values();
893        assert_eq!(value_data, values.to_data());
894        assert_eq!(DataType::Int32, list_array.value_type());
895        assert_eq!(9, list_array.len());
896        assert_eq!(4, list_array.null_count());
897        assert_eq!(2, list_array.value_offsets()[3]);
898        assert_eq!(2, list_array.value_length(3));
899
900        let sliced_array = list_array.slice(1, 6);
901        assert_eq!(6, sliced_array.len());
902        assert_eq!(3, sliced_array.null_count());
903
904        for i in 0..sliced_array.len() {
905            if bit_util::get_bit(&null_bits, 1 + i) {
906                assert!(sliced_array.is_valid(i));
907            } else {
908                assert!(sliced_array.is_null(i));
909            }
910        }
911
912        // Check offset and length for each non-null value.
913        let sliced_list_array = sliced_array.as_any().downcast_ref::<ListArray>().unwrap();
914        assert_eq!(2, sliced_list_array.value_offsets()[2]);
915        assert_eq!(2, sliced_list_array.value_length(2));
916        assert_eq!(4, sliced_list_array.value_offsets()[3]);
917        assert_eq!(2, sliced_list_array.value_length(3));
918        assert_eq!(6, sliced_list_array.value_offsets()[5]);
919        assert_eq!(3, sliced_list_array.value_length(5));
920    }
921
922    #[test]
923    fn test_large_list_array_slice() {
924        // Construct a value array
925        let value_data = ArrayData::builder(DataType::Int32)
926            .len(10)
927            .add_buffer(Buffer::from_slice_ref([0, 1, 2, 3, 4, 5, 6, 7, 8, 9]))
928            .build()
929            .unwrap();
930
931        // Construct a buffer for value offsets, for the nested array:
932        //  [[0, 1], null, null, [2, 3], [4, 5], null, [6, 7, 8], null, [9]]
933        let value_offsets = Buffer::from_slice_ref([0i64, 2, 2, 2, 4, 6, 6, 9, 9, 10]);
934        // 01011001 00000001
935        let mut null_bits: [u8; 2] = [0; 2];
936        bit_util::set_bit(&mut null_bits, 0);
937        bit_util::set_bit(&mut null_bits, 3);
938        bit_util::set_bit(&mut null_bits, 4);
939        bit_util::set_bit(&mut null_bits, 6);
940        bit_util::set_bit(&mut null_bits, 8);
941
942        // Construct a list array from the above two
943        let list_data_type = DataType::new_large_list(DataType::Int32, false);
944        let list_data = ArrayData::builder(list_data_type)
945            .len(9)
946            .add_buffer(value_offsets)
947            .add_child_data(value_data.clone())
948            .null_bit_buffer(Some(Buffer::from(null_bits)))
949            .build()
950            .unwrap();
951        let list_array = LargeListArray::from(list_data);
952
953        let values = list_array.values();
954        assert_eq!(value_data, values.to_data());
955        assert_eq!(DataType::Int32, list_array.value_type());
956        assert_eq!(9, list_array.len());
957        assert_eq!(4, list_array.null_count());
958        assert_eq!(2, list_array.value_offsets()[3]);
959        assert_eq!(2, list_array.value_length(3));
960
961        let sliced_array = list_array.slice(1, 6);
962        assert_eq!(6, sliced_array.len());
963        assert_eq!(3, sliced_array.null_count());
964
965        for i in 0..sliced_array.len() {
966            if bit_util::get_bit(&null_bits, 1 + i) {
967                assert!(sliced_array.is_valid(i));
968            } else {
969                assert!(sliced_array.is_null(i));
970            }
971        }
972
973        // Check offset and length for each non-null value.
974        let sliced_list_array = sliced_array
975            .as_any()
976            .downcast_ref::<LargeListArray>()
977            .unwrap();
978        assert_eq!(2, sliced_list_array.value_offsets()[2]);
979        assert_eq!(2, sliced_list_array.value_length(2));
980        assert_eq!(4, sliced_list_array.value_offsets()[3]);
981        assert_eq!(2, sliced_list_array.value_length(3));
982        assert_eq!(6, sliced_list_array.value_offsets()[5]);
983        assert_eq!(3, sliced_list_array.value_length(5));
984    }
985
986    #[test]
987    #[should_panic(expected = "index out of bounds: the len is 10 but the index is 11")]
988    fn test_list_array_index_out_of_bound() {
989        // Construct a value array
990        let value_data = ArrayData::builder(DataType::Int32)
991            .len(10)
992            .add_buffer(Buffer::from_slice_ref([0, 1, 2, 3, 4, 5, 6, 7, 8, 9]))
993            .build()
994            .unwrap();
995
996        // Construct a buffer for value offsets, for the nested array:
997        //  [[0, 1], null, null, [2, 3], [4, 5], null, [6, 7, 8], null, [9]]
998        let value_offsets = Buffer::from_slice_ref([0i64, 2, 2, 2, 4, 6, 6, 9, 9, 10]);
999        // 01011001 00000001
1000        let mut null_bits: [u8; 2] = [0; 2];
1001        bit_util::set_bit(&mut null_bits, 0);
1002        bit_util::set_bit(&mut null_bits, 3);
1003        bit_util::set_bit(&mut null_bits, 4);
1004        bit_util::set_bit(&mut null_bits, 6);
1005        bit_util::set_bit(&mut null_bits, 8);
1006
1007        // Construct a list array from the above two
1008        let list_data_type = DataType::new_large_list(DataType::Int32, false);
1009        let list_data = ArrayData::builder(list_data_type)
1010            .len(9)
1011            .add_buffer(value_offsets)
1012            .add_child_data(value_data)
1013            .null_bit_buffer(Some(Buffer::from(null_bits)))
1014            .build()
1015            .unwrap();
1016        let list_array = LargeListArray::from(list_data);
1017        assert_eq!(9, list_array.len());
1018
1019        list_array.value(10);
1020    }
1021    #[test]
1022    #[should_panic(expected = "ListArray data should contain a single buffer only (value offsets)")]
1023    // Different error messages, so skip for now
1024    // https://github.com/apache/arrow-rs/issues/1545
1025    #[cfg(not(feature = "force_validate"))]
1026    fn test_list_array_invalid_buffer_len() {
1027        let value_data = unsafe {
1028            ArrayData::builder(DataType::Int32)
1029                .len(8)
1030                .add_buffer(Buffer::from_slice_ref([0, 1, 2, 3, 4, 5, 6, 7]))
1031                .build_unchecked()
1032        };
1033        let list_data_type =
1034            DataType::List(Arc::new(Field::new_list_field(DataType::Int32, false)));
1035        let list_data = unsafe {
1036            ArrayData::builder(list_data_type)
1037                .len(3)
1038                .add_child_data(value_data)
1039                .build_unchecked()
1040        };
1041        drop(ListArray::from(list_data));
1042    }
1043
1044    #[test]
1045    #[should_panic(expected = "ListArray should contain a single child array (values array)")]
1046    // Different error messages, so skip for now
1047    // https://github.com/apache/arrow-rs/issues/1545
1048    #[cfg(not(feature = "force_validate"))]
1049    fn test_list_array_invalid_child_array_len() {
1050        let value_offsets = Buffer::from_slice_ref([0, 2, 5, 7]);
1051        let list_data_type =
1052            DataType::List(Arc::new(Field::new_list_field(DataType::Int32, false)));
1053        let list_data = unsafe {
1054            ArrayData::builder(list_data_type)
1055                .len(3)
1056                .add_buffer(value_offsets)
1057                .build_unchecked()
1058        };
1059        drop(ListArray::from(list_data));
1060    }
1061
1062    #[test]
1063    #[should_panic(expected = "[Large]ListArray's datatype must be [Large]ListArray(). It is List")]
1064    fn test_from_array_data_validation() {
1065        let mut builder = ListBuilder::new(Int32Builder::new());
1066        builder.values().append_value(1);
1067        builder.append(true);
1068        let array = builder.finish();
1069        let _ = LargeListArray::from(array.into_data());
1070    }
1071
1072    #[test]
1073    fn test_list_array_offsets_need_not_start_at_zero() {
1074        let value_data = ArrayData::builder(DataType::Int32)
1075            .len(8)
1076            .add_buffer(Buffer::from_slice_ref([0, 1, 2, 3, 4, 5, 6, 7]))
1077            .build()
1078            .unwrap();
1079
1080        let value_offsets = Buffer::from_slice_ref([2, 2, 5, 7]);
1081
1082        let list_data_type =
1083            DataType::List(Arc::new(Field::new_list_field(DataType::Int32, false)));
1084        let list_data = ArrayData::builder(list_data_type)
1085            .len(3)
1086            .add_buffer(value_offsets)
1087            .add_child_data(value_data)
1088            .build()
1089            .unwrap();
1090
1091        let list_array = ListArray::from(list_data);
1092        assert_eq!(list_array.value_length(0), 0);
1093        assert_eq!(list_array.value_length(1), 3);
1094        assert_eq!(list_array.value_length(2), 2);
1095    }
1096
1097    #[test]
1098    #[should_panic(expected = "Memory pointer is not aligned with the specified scalar type")]
1099    // Different error messages, so skip for now
1100    // https://github.com/apache/arrow-rs/issues/1545
1101    #[cfg(not(feature = "force_validate"))]
1102    fn test_primitive_array_alignment() {
1103        let buf = Buffer::from_slice_ref([0_u64]);
1104        let buf2 = buf.slice(1);
1105        let array_data = unsafe {
1106            ArrayData::builder(DataType::Int32)
1107                .add_buffer(buf2)
1108                .build_unchecked()
1109        };
1110        drop(Int32Array::from(array_data));
1111    }
1112
1113    #[test]
1114    #[should_panic(expected = "Memory pointer is not aligned with the specified scalar type")]
1115    // Different error messages, so skip for now
1116    // https://github.com/apache/arrow-rs/issues/1545
1117    #[cfg(not(feature = "force_validate"))]
1118    fn test_list_array_alignment() {
1119        let buf = Buffer::from_slice_ref([0_u64]);
1120        let buf2 = buf.slice(1);
1121
1122        let values: [i32; 8] = [0; 8];
1123        let value_data = unsafe {
1124            ArrayData::builder(DataType::Int32)
1125                .add_buffer(Buffer::from_slice_ref(values))
1126                .build_unchecked()
1127        };
1128
1129        let list_data_type =
1130            DataType::List(Arc::new(Field::new_list_field(DataType::Int32, false)));
1131        let list_data = unsafe {
1132            ArrayData::builder(list_data_type)
1133                .add_buffer(buf2)
1134                .add_child_data(value_data)
1135                .build_unchecked()
1136        };
1137        drop(ListArray::from(list_data));
1138    }
1139
1140    #[test]
1141    fn list_array_equality() {
1142        // test scaffold
1143        fn do_comparison(
1144            lhs_data: Vec<Option<Vec<Option<i32>>>>,
1145            rhs_data: Vec<Option<Vec<Option<i32>>>>,
1146            should_equal: bool,
1147        ) {
1148            let lhs = ListArray::from_iter_primitive::<Int32Type, _, _>(lhs_data.clone());
1149            let rhs = ListArray::from_iter_primitive::<Int32Type, _, _>(rhs_data.clone());
1150            assert_eq!(lhs == rhs, should_equal);
1151
1152            let lhs = LargeListArray::from_iter_primitive::<Int32Type, _, _>(lhs_data);
1153            let rhs = LargeListArray::from_iter_primitive::<Int32Type, _, _>(rhs_data);
1154            assert_eq!(lhs == rhs, should_equal);
1155        }
1156
1157        do_comparison(
1158            vec![
1159                Some(vec![Some(0), Some(1), Some(2)]),
1160                None,
1161                Some(vec![Some(3), None, Some(5)]),
1162                Some(vec![Some(6), Some(7)]),
1163            ],
1164            vec![
1165                Some(vec![Some(0), Some(1), Some(2)]),
1166                None,
1167                Some(vec![Some(3), None, Some(5)]),
1168                Some(vec![Some(6), Some(7)]),
1169            ],
1170            true,
1171        );
1172
1173        do_comparison(
1174            vec![
1175                None,
1176                None,
1177                Some(vec![Some(3), None, Some(5)]),
1178                Some(vec![Some(6), Some(7)]),
1179            ],
1180            vec![
1181                Some(vec![Some(0), Some(1), Some(2)]),
1182                None,
1183                Some(vec![Some(3), None, Some(5)]),
1184                Some(vec![Some(6), Some(7)]),
1185            ],
1186            false,
1187        );
1188
1189        do_comparison(
1190            vec![
1191                None,
1192                None,
1193                Some(vec![Some(3), None, Some(5)]),
1194                Some(vec![Some(6), Some(7)]),
1195            ],
1196            vec![
1197                None,
1198                None,
1199                Some(vec![Some(3), None, Some(5)]),
1200                Some(vec![Some(0), Some(0)]),
1201            ],
1202            false,
1203        );
1204
1205        do_comparison(
1206            vec![None, None, Some(vec![Some(1)])],
1207            vec![None, None, Some(vec![Some(2)])],
1208            false,
1209        );
1210    }
1211
1212    #[test]
1213    fn test_empty_offsets() {
1214        let f = Arc::new(Field::new("element", DataType::Int32, true));
1215        let string = ListArray::from(
1216            ArrayData::builder(DataType::List(f.clone()))
1217                .buffers(vec![Buffer::from(&[])])
1218                .add_child_data(ArrayData::new_empty(&DataType::Int32))
1219                .build()
1220                .unwrap(),
1221        );
1222        assert_eq!(string.value_offsets(), &[0]);
1223        let string = LargeListArray::from(
1224            ArrayData::builder(DataType::LargeList(f))
1225                .buffers(vec![Buffer::from(&[])])
1226                .add_child_data(ArrayData::new_empty(&DataType::Int32))
1227                .build()
1228                .unwrap(),
1229        );
1230        assert_eq!(string.len(), 0);
1231        assert_eq!(string.value_offsets(), &[0]);
1232    }
1233
1234    #[test]
1235    fn test_try_new() {
1236        let offsets = OffsetBuffer::new(vec![0, 1, 4, 5].into());
1237        let values = Int32Array::new(vec![1, 2, 3, 4, 5].into(), None);
1238        let values = Arc::new(values) as ArrayRef;
1239
1240        let field = Arc::new(Field::new("element", DataType::Int32, false));
1241        ListArray::new(field.clone(), offsets.clone(), values.clone(), None);
1242
1243        let nulls = NullBuffer::new_null(3);
1244        ListArray::new(field.clone(), offsets, values.clone(), Some(nulls));
1245
1246        let nulls = NullBuffer::new_null(3);
1247        let offsets = OffsetBuffer::new(vec![0, 1, 2, 4, 5].into());
1248        let err = LargeListArray::try_new(field, offsets.clone(), values.clone(), Some(nulls))
1249            .unwrap_err();
1250
1251        assert_eq!(
1252            err.to_string(),
1253            "Invalid argument error: Incorrect length of null buffer for LargeListArray, expected 4 got 3"
1254        );
1255
1256        let field = Arc::new(Field::new("element", DataType::Int64, false));
1257        let err = LargeListArray::try_new(field.clone(), offsets.clone(), values.clone(), None)
1258            .unwrap_err();
1259
1260        assert_eq!(
1261            err.to_string(),
1262            "Invalid argument error: LargeListArray expected data type Int64 got Int32 for \"element\""
1263        );
1264
1265        let nulls = NullBuffer::new_null(7);
1266        let values = Int64Array::new(vec![0; 7].into(), Some(nulls));
1267        let values = Arc::new(values);
1268
1269        let err =
1270            LargeListArray::try_new(field, offsets.clone(), values.clone(), None).unwrap_err();
1271
1272        assert_eq!(
1273            err.to_string(),
1274            "Invalid argument error: Non-nullable field of LargeListArray \"element\" cannot contain nulls"
1275        );
1276
1277        let field = Arc::new(Field::new("element", DataType::Int64, true));
1278        LargeListArray::new(field.clone(), offsets.clone(), values, None);
1279
1280        let values = Int64Array::new(vec![0; 2].into(), None);
1281        let err = LargeListArray::try_new(field, offsets, Arc::new(values), None).unwrap_err();
1282
1283        assert_eq!(
1284            err.to_string(),
1285            "Invalid argument error: Max offset of 5 exceeds length of values 2"
1286        );
1287    }
1288
1289    #[test]
1290    fn test_from_fixed_size_list() {
1291        let mut builder = FixedSizeListBuilder::new(Int32Builder::new(), 3);
1292        builder.values().append_slice(&[1, 2, 3]);
1293        builder.append(true);
1294        builder.values().append_slice(&[0, 0, 0]);
1295        builder.append(false);
1296        builder.values().append_slice(&[4, 5, 6]);
1297        builder.append(true);
1298        let list: ListArray = builder.finish().into();
1299
1300        let values: Vec<_> = list
1301            .iter()
1302            .map(|x| x.map(|x| x.as_primitive::<Int32Type>().values().to_vec()))
1303            .collect();
1304        assert_eq!(values, vec![Some(vec![1, 2, 3]), None, Some(vec![4, 5, 6])])
1305    }
1306
1307    #[test]
1308    fn test_nullable_union() {
1309        let offsets = OffsetBuffer::new(vec![0, 1, 4, 5].into());
1310        let mut builder = UnionBuilder::new_dense();
1311        builder.append::<Int32Type>("a", 1).unwrap();
1312        builder.append::<Int32Type>("b", 2).unwrap();
1313        builder.append::<Int32Type>("b", 3).unwrap();
1314        builder.append::<Int32Type>("a", 4).unwrap();
1315        builder.append::<Int32Type>("a", 5).unwrap();
1316        let values = builder.build().unwrap();
1317        let field = Arc::new(Field::new("element", values.data_type().clone(), false));
1318        ListArray::new(field.clone(), offsets, Arc::new(values), None);
1319    }
1320
1321    #[test]
1322    fn test_list_new_null_len() {
1323        let field = Arc::new(Field::new_list_field(DataType::Int32, true));
1324        let array = ListArray::new_null(field, 5);
1325        assert_eq!(array.len(), 5);
1326    }
1327
1328    #[test]
1329    fn test_list_from_iter_i32() {
1330        let array = ListArray::from_nested_iter::<Int32Builder, _, _, _>(vec![
1331            None,
1332            Some(vec![Some(1), None, Some(2)]),
1333        ]);
1334        let expected_offsets = &[0, 0, 3];
1335        let expected_values: ArrayRef = Arc::new(Int32Array::from(vec![Some(1), None, Some(2)]));
1336        assert_eq!(array.value_offsets(), expected_offsets);
1337        assert_eq!(array.values(), &expected_values);
1338    }
1339
1340    #[test]
1341    fn test_list_from_iter_bool() {
1342        let array = ListArray::from_nested_iter::<BooleanBuilder, _, _, _>(vec![
1343            Some(vec![None, Some(false), Some(true)]),
1344            None,
1345        ]);
1346        let expected_offsets = &[0, 3, 3];
1347        let expected_values: ArrayRef =
1348            Arc::new(BooleanArray::from(vec![None, Some(false), Some(true)]));
1349        assert_eq!(array.value_offsets(), expected_offsets);
1350        assert_eq!(array.values(), &expected_values);
1351    }
1352
1353    #[test]
1354    fn test_list_from_iter_str() {
1355        let array = ListArray::from_nested_iter::<StringBuilder, _, _, _>(vec![
1356            Some(vec![Some("foo"), None, Some("bar")]),
1357            None,
1358        ]);
1359        let expected_offsets = &[0, 3, 3];
1360        let expected_values: ArrayRef =
1361            Arc::new(StringArray::from(vec![Some("foo"), None, Some("bar")]));
1362        assert_eq!(array.value_offsets(), expected_offsets);
1363        assert_eq!(array.values(), &expected_values);
1364    }
1365
1366    #[test]
1367    fn test_list_from_iter_dict_str() {
1368        let array =
1369            ListArray::from_nested_iter::<StringDictionaryBuilder<Int8Type>, _, _, _>(vec![
1370                Some(vec![Some("foo"), None, Some("bar"), Some("foo")]),
1371                None,
1372            ]);
1373        let expected_offsets = &[0, 4, 4];
1374        let expected_dict_values: ArrayRef =
1375            Arc::new(StringArray::from(vec![Some("foo"), Some("bar")]));
1376        let expected_dict_keys = Int8Array::from(vec![Some(0), None, Some(1), Some(0)]);
1377        let expected_values: ArrayRef = Arc::new(
1378            Int8DictionaryArray::try_new(expected_dict_keys, expected_dict_values).unwrap(),
1379        );
1380        assert_eq!(array.value_offsets(), expected_offsets);
1381        assert_eq!(array.values(), &expected_values);
1382    }
1383}
arrow_array/array/list_array.rs

arrow_array/array/
list_array.rs
