arrow_array/array/
struct_array.rs

1// Licensed to the Apache Software Foundation (ASF) under one
2// or more contributor license agreements.  See the NOTICE file
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4// regarding copyright ownership.  The ASF licenses this file
5// to you under the Apache License, Version 2.0 (the
6// "License"); you may not use this file except in compliance
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8//
9//   http://www.apache.org/licenses/LICENSE-2.0
10//
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12// software distributed under the License is distributed on an
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14// KIND, either express or implied.  See the License for the
15// specific language governing permissions and limitations
16// under the License.
17
18use crate::array::print_long_array;
19use crate::{make_array, new_null_array, Array, ArrayRef, RecordBatch};
20use arrow_buffer::{BooleanBuffer, Buffer, NullBuffer};
21use arrow_data::{ArrayData, ArrayDataBuilder};
22use arrow_schema::{ArrowError, DataType, Field, FieldRef, Fields};
23use std::sync::Arc;
24use std::{any::Any, ops::Index};
25
26/// An array of [structs](https://arrow.apache.org/docs/format/Columnar.html#struct-layout)
27///
28/// Each child (called *field*) is represented by a separate array.
29///
30/// # Comparison with [RecordBatch]
31///
32/// Both [`RecordBatch`] and [`StructArray`] represent a collection of columns / arrays with the
33/// same length.
34///
35/// However, there are a couple of key differences:
36///
37/// * [`StructArray`] can be nested within other [`Array`], including itself
38/// * [`RecordBatch`] can contain top-level metadata on its associated [`Schema`][arrow_schema::Schema]
39/// * [`StructArray`] can contain top-level nulls, i.e. `null`
40/// * [`RecordBatch`] can only represent nulls in its child columns, i.e. `{"field": null}`
41///
42/// [`StructArray`] is therefore a more general data container than [`RecordBatch`], and as such
43/// code that needs to handle both will typically share an implementation in terms of
44/// [`StructArray`] and convert to/from [`RecordBatch`] as necessary.
45///
46/// [`From`] implementations are provided to facilitate this conversion, however, converting
47/// from a [`StructArray`] containing top-level nulls to a [`RecordBatch`] will panic, as there
48/// is no way to preserve them.
49///
50/// # Example: Create an array from a vector of fields
51///
52/// ```
53/// use std::sync::Arc;
54/// use arrow_array::{Array, ArrayRef, BooleanArray, Int32Array, StructArray};
55/// use arrow_schema::{DataType, Field};
56///
57/// let boolean = Arc::new(BooleanArray::from(vec![false, false, true, true]));
58/// let int = Arc::new(Int32Array::from(vec![42, 28, 19, 31]));
59///
60/// let struct_array = StructArray::from(vec![
61///     (
62///         Arc::new(Field::new("b", DataType::Boolean, false)),
63///         boolean.clone() as ArrayRef,
64///     ),
65///     (
66///         Arc::new(Field::new("c", DataType::Int32, false)),
67///         int.clone() as ArrayRef,
68///     ),
69/// ]);
70/// assert_eq!(struct_array.column(0).as_ref(), boolean.as_ref());
71/// assert_eq!(struct_array.column(1).as_ref(), int.as_ref());
72/// assert_eq!(4, struct_array.len());
73/// assert_eq!(0, struct_array.null_count());
74/// assert_eq!(0, struct_array.offset());
75/// ```
76#[derive(Clone)]
77pub struct StructArray {
78    len: usize,
79    data_type: DataType,
80    nulls: Option<NullBuffer>,
81    fields: Vec<ArrayRef>,
82}
83
84impl StructArray {
85    /// Create a new [`StructArray`] from the provided parts, panicking on failure
86    ///
87    /// # Panics
88    ///
89    /// Panics if [`Self::try_new`] returns an error
90    pub fn new(fields: Fields, arrays: Vec<ArrayRef>, nulls: Option<NullBuffer>) -> Self {
91        Self::try_new(fields, arrays, nulls).unwrap()
92    }
93
94    /// Create a new [`StructArray`] from the provided parts, returning an error on failure
95    ///
96    /// # Errors
97    ///
98    /// Errors if
99    ///
100    /// * `fields.len() != arrays.len()`
101    /// * `fields[i].data_type() != arrays[i].data_type()`
102    /// * `arrays[i].len() != arrays[j].len()`
103    /// * `arrays[i].len() != nulls.len()`
104    /// * `!fields[i].is_nullable() && !nulls.contains(arrays[i].nulls())`
105    pub fn try_new(
106        fields: Fields,
107        arrays: Vec<ArrayRef>,
108        nulls: Option<NullBuffer>,
109    ) -> Result<Self, ArrowError> {
110        if fields.len() != arrays.len() {
111            return Err(ArrowError::InvalidArgumentError(format!(
112                "Incorrect number of arrays for StructArray fields, expected {} got {}",
113                fields.len(),
114                arrays.len()
115            )));
116        }
117        let len = arrays.first().map(|x| x.len()).unwrap_or_default();
118
119        if let Some(n) = nulls.as_ref() {
120            if n.len() != len {
121                return Err(ArrowError::InvalidArgumentError(format!(
122                    "Incorrect number of nulls for StructArray, expected {len} got {}",
123                    n.len(),
124                )));
125            }
126        }
127
128        for (f, a) in fields.iter().zip(&arrays) {
129            if f.data_type() != a.data_type() {
130                return Err(ArrowError::InvalidArgumentError(format!(
131                    "Incorrect datatype for StructArray field {:?}, expected {} got {}",
132                    f.name(),
133                    f.data_type(),
134                    a.data_type()
135                )));
136            }
137
138            if a.len() != len {
139                return Err(ArrowError::InvalidArgumentError(format!(
140                    "Incorrect array length for StructArray field {:?}, expected {} got {}",
141                    f.name(),
142                    len,
143                    a.len()
144                )));
145            }
146
147            if !f.is_nullable() {
148                if let Some(a) = a.logical_nulls() {
149                    if !nulls.as_ref().map(|n| n.contains(&a)).unwrap_or_default() {
150                        return Err(ArrowError::InvalidArgumentError(format!(
151                            "Found unmasked nulls for non-nullable StructArray field {:?}",
152                            f.name()
153                        )));
154                    }
155                }
156            }
157        }
158
159        Ok(Self {
160            len,
161            data_type: DataType::Struct(fields),
162            nulls: nulls.filter(|n| n.null_count() > 0),
163            fields: arrays,
164        })
165    }
166
167    /// Create a new [`StructArray`] of length `len` where all values are null
168    pub fn new_null(fields: Fields, len: usize) -> Self {
169        let arrays = fields
170            .iter()
171            .map(|f| new_null_array(f.data_type(), len))
172            .collect();
173
174        Self {
175            len,
176            data_type: DataType::Struct(fields),
177            nulls: Some(NullBuffer::new_null(len)),
178            fields: arrays,
179        }
180    }
181
182    /// Create a new [`StructArray`] from the provided parts without validation
183    ///
184    /// # Safety
185    ///
186    /// Safe if [`Self::new`] would not panic with the given arguments
187    pub unsafe fn new_unchecked(
188        fields: Fields,
189        arrays: Vec<ArrayRef>,
190        nulls: Option<NullBuffer>,
191    ) -> Self {
192        let len = arrays.first().map(|x| x.len()).unwrap_or_default();
193        Self {
194            len,
195            data_type: DataType::Struct(fields),
196            nulls,
197            fields: arrays,
198        }
199    }
200
201    /// Create a new [`StructArray`] containing no fields
202    ///
203    /// # Panics
204    ///
205    /// If `len != nulls.len()`
206    pub fn new_empty_fields(len: usize, nulls: Option<NullBuffer>) -> Self {
207        if let Some(n) = &nulls {
208            assert_eq!(len, n.len())
209        }
210        Self {
211            len,
212            data_type: DataType::Struct(Fields::empty()),
213            fields: vec![],
214            nulls,
215        }
216    }
217
218    /// Deconstruct this array into its constituent parts
219    pub fn into_parts(self) -> (Fields, Vec<ArrayRef>, Option<NullBuffer>) {
220        let f = match self.data_type {
221            DataType::Struct(f) => f,
222            _ => unreachable!(),
223        };
224        (f, self.fields, self.nulls)
225    }
226
227    /// Returns the field at `pos`.
228    pub fn column(&self, pos: usize) -> &ArrayRef {
229        &self.fields[pos]
230    }
231
232    /// Return the number of fields in this struct array
233    pub fn num_columns(&self) -> usize {
234        self.fields.len()
235    }
236
237    /// Returns the fields of the struct array
238    pub fn columns(&self) -> &[ArrayRef] {
239        &self.fields
240    }
241
242    /// Return field names in this struct array
243    pub fn column_names(&self) -> Vec<&str> {
244        match self.data_type() {
245            DataType::Struct(fields) => fields
246                .iter()
247                .map(|f| f.name().as_str())
248                .collect::<Vec<&str>>(),
249            _ => unreachable!("Struct array's data type is not struct!"),
250        }
251    }
252
253    /// Returns the [`Fields`] of this [`StructArray`]
254    pub fn fields(&self) -> &Fields {
255        match self.data_type() {
256            DataType::Struct(f) => f,
257            _ => unreachable!(),
258        }
259    }
260
261    /// Return child array whose field name equals to column_name
262    ///
263    /// Note: A schema can currently have duplicate field names, in which case
264    /// the first field will always be selected.
265    /// This issue will be addressed in [ARROW-11178](https://issues.apache.org/jira/browse/ARROW-11178)
266    pub fn column_by_name(&self, column_name: &str) -> Option<&ArrayRef> {
267        self.column_names()
268            .iter()
269            .position(|c| c == &column_name)
270            .map(|pos| self.column(pos))
271    }
272
273    /// Returns a zero-copy slice of this array with the indicated offset and length.
274    pub fn slice(&self, offset: usize, len: usize) -> Self {
275        assert!(
276            offset.saturating_add(len) <= self.len,
277            "the length + offset of the sliced StructArray cannot exceed the existing length"
278        );
279
280        let fields = self.fields.iter().map(|a| a.slice(offset, len)).collect();
281
282        Self {
283            len,
284            data_type: self.data_type.clone(),
285            nulls: self.nulls.as_ref().map(|n| n.slice(offset, len)),
286            fields,
287        }
288    }
289}
290
291impl From<ArrayData> for StructArray {
292    fn from(data: ArrayData) -> Self {
293        let fields = data
294            .child_data()
295            .iter()
296            .map(|cd| make_array(cd.clone()))
297            .collect();
298
299        Self {
300            len: data.len(),
301            data_type: data.data_type().clone(),
302            nulls: data.nulls().cloned(),
303            fields,
304        }
305    }
306}
307
308impl From<StructArray> for ArrayData {
309    fn from(array: StructArray) -> Self {
310        let builder = ArrayDataBuilder::new(array.data_type)
311            .len(array.len)
312            .nulls(array.nulls)
313            .child_data(array.fields.iter().map(|x| x.to_data()).collect());
314
315        unsafe { builder.build_unchecked() }
316    }
317}
318
319impl TryFrom<Vec<(&str, ArrayRef)>> for StructArray {
320    type Error = ArrowError;
321
322    /// builds a StructArray from a vector of names and arrays.
323    fn try_from(values: Vec<(&str, ArrayRef)>) -> Result<Self, ArrowError> {
324        let (fields, arrays): (Vec<_>, _) = values
325            .into_iter()
326            .map(|(name, array)| {
327                (
328                    Field::new(name, array.data_type().clone(), array.is_nullable()),
329                    array,
330                )
331            })
332            .unzip();
333
334        StructArray::try_new(fields.into(), arrays, None)
335    }
336}
337
338impl Array for StructArray {
339    fn as_any(&self) -> &dyn Any {
340        self
341    }
342
343    fn to_data(&self) -> ArrayData {
344        self.clone().into()
345    }
346
347    fn into_data(self) -> ArrayData {
348        self.into()
349    }
350
351    fn data_type(&self) -> &DataType {
352        &self.data_type
353    }
354
355    fn slice(&self, offset: usize, length: usize) -> ArrayRef {
356        Arc::new(self.slice(offset, length))
357    }
358
359    fn len(&self) -> usize {
360        self.len
361    }
362
363    fn is_empty(&self) -> bool {
364        self.len == 0
365    }
366
367    fn shrink_to_fit(&mut self) {
368        if let Some(nulls) = &mut self.nulls {
369            nulls.shrink_to_fit();
370        }
371        self.fields.iter_mut().for_each(|n| n.shrink_to_fit());
372    }
373
374    fn offset(&self) -> usize {
375        0
376    }
377
378    fn nulls(&self) -> Option<&NullBuffer> {
379        self.nulls.as_ref()
380    }
381
382    fn logical_null_count(&self) -> usize {
383        // More efficient that the default implementation
384        self.null_count()
385    }
386
387    fn get_buffer_memory_size(&self) -> usize {
388        let mut size = self.fields.iter().map(|a| a.get_buffer_memory_size()).sum();
389        if let Some(n) = self.nulls.as_ref() {
390            size += n.buffer().capacity();
391        }
392        size
393    }
394
395    fn get_array_memory_size(&self) -> usize {
396        let mut size = self.fields.iter().map(|a| a.get_array_memory_size()).sum();
397        size += std::mem::size_of::<Self>();
398        if let Some(n) = self.nulls.as_ref() {
399            size += n.buffer().capacity();
400        }
401        size
402    }
403}
404
405impl From<Vec<(FieldRef, ArrayRef)>> for StructArray {
406    fn from(v: Vec<(FieldRef, ArrayRef)>) -> Self {
407        let (fields, arrays): (Vec<_>, _) = v.into_iter().unzip();
408        StructArray::new(fields.into(), arrays, None)
409    }
410}
411
412impl std::fmt::Debug for StructArray {
413    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
414        writeln!(f, "StructArray")?;
415        writeln!(f, "-- validity: ")?;
416        writeln!(f, "[")?;
417        print_long_array(self, f, |_array, _index, f| write!(f, "valid"))?;
418        writeln!(f, "]\n[")?;
419        for (child_index, name) in self.column_names().iter().enumerate() {
420            let column = self.column(child_index);
421            writeln!(
422                f,
423                "-- child {}: \"{}\" ({:?})",
424                child_index,
425                name,
426                column.data_type()
427            )?;
428            std::fmt::Debug::fmt(column, f)?;
429            writeln!(f)?;
430        }
431        write!(f, "]")
432    }
433}
434
435impl From<(Vec<(FieldRef, ArrayRef)>, Buffer)> for StructArray {
436    fn from(pair: (Vec<(FieldRef, ArrayRef)>, Buffer)) -> Self {
437        let len = pair.0.first().map(|x| x.1.len()).unwrap_or_default();
438        let (fields, arrays): (Vec<_>, Vec<_>) = pair.0.into_iter().unzip();
439        let nulls = NullBuffer::new(BooleanBuffer::new(pair.1, 0, len));
440        Self::new(fields.into(), arrays, Some(nulls))
441    }
442}
443
444impl From<RecordBatch> for StructArray {
445    fn from(value: RecordBatch) -> Self {
446        Self {
447            len: value.num_rows(),
448            data_type: DataType::Struct(value.schema().fields().clone()),
449            nulls: None,
450            fields: value.columns().to_vec(),
451        }
452    }
453}
454
455impl Index<&str> for StructArray {
456    type Output = ArrayRef;
457
458    /// Get a reference to a column's array by name.
459    ///
460    /// Note: A schema can currently have duplicate field names, in which case
461    /// the first field will always be selected.
462    /// This issue will be addressed in [ARROW-11178](https://issues.apache.org/jira/browse/ARROW-11178)
463    ///
464    /// # Panics
465    ///
466    /// Panics if the name is not in the schema.
467    fn index(&self, name: &str) -> &Self::Output {
468        self.column_by_name(name).unwrap()
469    }
470}
471
472#[cfg(test)]
473mod tests {
474    use super::*;
475
476    use crate::{BooleanArray, Float32Array, Float64Array, Int32Array, Int64Array, StringArray};
477    use arrow_buffer::ToByteSlice;
478
479    #[test]
480    fn test_struct_array_builder() {
481        let boolean_array = BooleanArray::from(vec![false, false, true, true]);
482        let int_array = Int64Array::from(vec![42, 28, 19, 31]);
483
484        let fields = vec![
485            Field::new("a", DataType::Boolean, false),
486            Field::new("b", DataType::Int64, false),
487        ];
488        let struct_array_data = ArrayData::builder(DataType::Struct(fields.into()))
489            .len(4)
490            .add_child_data(boolean_array.to_data())
491            .add_child_data(int_array.to_data())
492            .build()
493            .unwrap();
494        let struct_array = StructArray::from(struct_array_data);
495
496        assert_eq!(struct_array.column(0).as_ref(), &boolean_array);
497        assert_eq!(struct_array.column(1).as_ref(), &int_array);
498    }
499
500    #[test]
501    fn test_struct_array_from() {
502        let boolean = Arc::new(BooleanArray::from(vec![false, false, true, true]));
503        let int = Arc::new(Int32Array::from(vec![42, 28, 19, 31]));
504
505        let struct_array = StructArray::from(vec![
506            (
507                Arc::new(Field::new("b", DataType::Boolean, false)),
508                boolean.clone() as ArrayRef,
509            ),
510            (
511                Arc::new(Field::new("c", DataType::Int32, false)),
512                int.clone() as ArrayRef,
513            ),
514        ]);
515        assert_eq!(struct_array.column(0).as_ref(), boolean.as_ref());
516        assert_eq!(struct_array.column(1).as_ref(), int.as_ref());
517        assert_eq!(4, struct_array.len());
518        assert_eq!(0, struct_array.null_count());
519        assert_eq!(0, struct_array.offset());
520    }
521
522    /// validates that struct can be accessed using `column_name` as index i.e. `struct_array["column_name"]`.
523    #[test]
524    fn test_struct_array_index_access() {
525        let boolean = Arc::new(BooleanArray::from(vec![false, false, true, true]));
526        let int = Arc::new(Int32Array::from(vec![42, 28, 19, 31]));
527
528        let struct_array = StructArray::from(vec![
529            (
530                Arc::new(Field::new("b", DataType::Boolean, false)),
531                boolean.clone() as ArrayRef,
532            ),
533            (
534                Arc::new(Field::new("c", DataType::Int32, false)),
535                int.clone() as ArrayRef,
536            ),
537        ]);
538        assert_eq!(struct_array["b"].as_ref(), boolean.as_ref());
539        assert_eq!(struct_array["c"].as_ref(), int.as_ref());
540    }
541
542    /// validates that the in-memory representation follows [the spec](https://arrow.apache.org/docs/format/Columnar.html#struct-layout)
543    #[test]
544    fn test_struct_array_from_vec() {
545        let strings: ArrayRef = Arc::new(StringArray::from(vec![
546            Some("joe"),
547            None,
548            None,
549            Some("mark"),
550        ]));
551        let ints: ArrayRef = Arc::new(Int32Array::from(vec![Some(1), Some(2), None, Some(4)]));
552
553        let arr =
554            StructArray::try_from(vec![("f1", strings.clone()), ("f2", ints.clone())]).unwrap();
555
556        let struct_data = arr.into_data();
557        assert_eq!(4, struct_data.len());
558        assert_eq!(0, struct_data.null_count());
559
560        let expected_string_data = ArrayData::builder(DataType::Utf8)
561            .len(4)
562            .null_bit_buffer(Some(Buffer::from(&[9_u8])))
563            .add_buffer(Buffer::from([0, 3, 3, 3, 7].to_byte_slice()))
564            .add_buffer(Buffer::from(b"joemark"))
565            .build()
566            .unwrap();
567
568        let expected_int_data = ArrayData::builder(DataType::Int32)
569            .len(4)
570            .null_bit_buffer(Some(Buffer::from(&[11_u8])))
571            .add_buffer(Buffer::from([1, 2, 0, 4].to_byte_slice()))
572            .build()
573            .unwrap();
574
575        assert_eq!(expected_string_data, struct_data.child_data()[0]);
576        assert_eq!(expected_int_data, struct_data.child_data()[1]);
577    }
578
579    #[test]
580    fn test_struct_array_from_vec_error() {
581        let strings: ArrayRef = Arc::new(StringArray::from(vec![
582            Some("joe"),
583            None,
584            None,
585            // 3 elements, not 4
586        ]));
587        let ints: ArrayRef = Arc::new(Int32Array::from(vec![Some(1), Some(2), None, Some(4)]));
588
589        let err = StructArray::try_from(vec![("f1", strings.clone()), ("f2", ints.clone())])
590            .unwrap_err()
591            .to_string();
592
593        assert_eq!(
594            err,
595            "Invalid argument error: Incorrect array length for StructArray field \"f2\", expected 3 got 4"
596        )
597    }
598
599    #[test]
600    #[should_panic(
601        expected = "Incorrect datatype for StructArray field \\\"b\\\", expected Int16 got Boolean"
602    )]
603    fn test_struct_array_from_mismatched_types_single() {
604        drop(StructArray::from(vec![(
605            Arc::new(Field::new("b", DataType::Int16, false)),
606            Arc::new(BooleanArray::from(vec![false, false, true, true])) as Arc<dyn Array>,
607        )]));
608    }
609
610    #[test]
611    #[should_panic(
612        expected = "Incorrect datatype for StructArray field \\\"b\\\", expected Int16 got Boolean"
613    )]
614    fn test_struct_array_from_mismatched_types_multiple() {
615        drop(StructArray::from(vec![
616            (
617                Arc::new(Field::new("b", DataType::Int16, false)),
618                Arc::new(BooleanArray::from(vec![false, false, true, true])) as Arc<dyn Array>,
619            ),
620            (
621                Arc::new(Field::new("c", DataType::Utf8, false)),
622                Arc::new(Int32Array::from(vec![42, 28, 19, 31])),
623            ),
624        ]));
625    }
626
627    #[test]
628    fn test_struct_array_slice() {
629        let boolean_data = ArrayData::builder(DataType::Boolean)
630            .len(5)
631            .add_buffer(Buffer::from([0b00010000]))
632            .null_bit_buffer(Some(Buffer::from([0b00010001])))
633            .build()
634            .unwrap();
635        let int_data = ArrayData::builder(DataType::Int32)
636            .len(5)
637            .add_buffer(Buffer::from([0, 28, 42, 0, 0].to_byte_slice()))
638            .null_bit_buffer(Some(Buffer::from([0b00000110])))
639            .build()
640            .unwrap();
641
642        let field_types = vec![
643            Field::new("a", DataType::Boolean, true),
644            Field::new("b", DataType::Int32, true),
645        ];
646        let struct_array_data = ArrayData::builder(DataType::Struct(field_types.into()))
647            .len(5)
648            .add_child_data(boolean_data.clone())
649            .add_child_data(int_data.clone())
650            .null_bit_buffer(Some(Buffer::from([0b00010111])))
651            .build()
652            .unwrap();
653        let struct_array = StructArray::from(struct_array_data);
654
655        assert_eq!(5, struct_array.len());
656        assert_eq!(1, struct_array.null_count());
657        assert!(struct_array.is_valid(0));
658        assert!(struct_array.is_valid(1));
659        assert!(struct_array.is_valid(2));
660        assert!(struct_array.is_null(3));
661        assert!(struct_array.is_valid(4));
662        assert_eq!(boolean_data, struct_array.column(0).to_data());
663        assert_eq!(int_data, struct_array.column(1).to_data());
664
665        let c0 = struct_array.column(0);
666        let c0 = c0.as_any().downcast_ref::<BooleanArray>().unwrap();
667        assert_eq!(5, c0.len());
668        assert_eq!(3, c0.null_count());
669        assert!(c0.is_valid(0));
670        assert!(!c0.value(0));
671        assert!(c0.is_null(1));
672        assert!(c0.is_null(2));
673        assert!(c0.is_null(3));
674        assert!(c0.is_valid(4));
675        assert!(c0.value(4));
676
677        let c1 = struct_array.column(1);
678        let c1 = c1.as_any().downcast_ref::<Int32Array>().unwrap();
679        assert_eq!(5, c1.len());
680        assert_eq!(3, c1.null_count());
681        assert!(c1.is_null(0));
682        assert!(c1.is_valid(1));
683        assert_eq!(28, c1.value(1));
684        assert!(c1.is_valid(2));
685        assert_eq!(42, c1.value(2));
686        assert!(c1.is_null(3));
687        assert!(c1.is_null(4));
688
689        let sliced_array = struct_array.slice(2, 3);
690        let sliced_array = sliced_array.as_any().downcast_ref::<StructArray>().unwrap();
691        assert_eq!(3, sliced_array.len());
692        assert_eq!(1, sliced_array.null_count());
693        assert!(sliced_array.is_valid(0));
694        assert!(sliced_array.is_null(1));
695        assert!(sliced_array.is_valid(2));
696
697        let sliced_c0 = sliced_array.column(0);
698        let sliced_c0 = sliced_c0.as_any().downcast_ref::<BooleanArray>().unwrap();
699        assert_eq!(3, sliced_c0.len());
700        assert!(sliced_c0.is_null(0));
701        assert!(sliced_c0.is_null(1));
702        assert!(sliced_c0.is_valid(2));
703        assert!(sliced_c0.value(2));
704
705        let sliced_c1 = sliced_array.column(1);
706        let sliced_c1 = sliced_c1.as_any().downcast_ref::<Int32Array>().unwrap();
707        assert_eq!(3, sliced_c1.len());
708        assert!(sliced_c1.is_valid(0));
709        assert_eq!(42, sliced_c1.value(0));
710        assert!(sliced_c1.is_null(1));
711        assert!(sliced_c1.is_null(2));
712    }
713
714    #[test]
715    #[should_panic(
716        expected = "Incorrect array length for StructArray field \\\"c\\\", expected 1 got 2"
717    )]
718    fn test_invalid_struct_child_array_lengths() {
719        drop(StructArray::from(vec![
720            (
721                Arc::new(Field::new("b", DataType::Float32, false)),
722                Arc::new(Float32Array::from(vec![1.1])) as Arc<dyn Array>,
723            ),
724            (
725                Arc::new(Field::new("c", DataType::Float64, false)),
726                Arc::new(Float64Array::from(vec![2.2, 3.3])),
727            ),
728        ]));
729    }
730
731    #[test]
732    fn test_struct_array_from_empty() {
733        let sa = StructArray::from(vec![]);
734        assert!(sa.is_empty())
735    }
736
737    #[test]
738    #[should_panic(expected = "Found unmasked nulls for non-nullable StructArray field \\\"c\\\"")]
739    fn test_struct_array_from_mismatched_nullability() {
740        drop(StructArray::from(vec![(
741            Arc::new(Field::new("c", DataType::Int32, false)),
742            Arc::new(Int32Array::from(vec![Some(42), None, Some(19)])) as ArrayRef,
743        )]));
744    }
745
746    #[test]
747    fn test_struct_array_fmt_debug() {
748        let arr: StructArray = StructArray::new(
749            vec![Arc::new(Field::new("c", DataType::Int32, true))].into(),
750            vec![Arc::new(Int32Array::from((0..30).collect::<Vec<_>>())) as ArrayRef],
751            Some(NullBuffer::new(BooleanBuffer::from(
752                (0..30).map(|i| i % 2 == 0).collect::<Vec<_>>(),
753            ))),
754        );
755        assert_eq!(format!("{arr:?}"), "StructArray\n-- validity: \n[\n  valid,\n  null,\n  valid,\n  null,\n  valid,\n  null,\n  valid,\n  null,\n  valid,\n  null,\n  ...10 elements...,\n  valid,\n  null,\n  valid,\n  null,\n  valid,\n  null,\n  valid,\n  null,\n  valid,\n  null,\n]\n[\n-- child 0: \"c\" (Int32)\nPrimitiveArray<Int32>\n[\n  0,\n  1,\n  2,\n  3,\n  4,\n  5,\n  6,\n  7,\n  8,\n  9,\n  ...10 elements...,\n  20,\n  21,\n  22,\n  23,\n  24,\n  25,\n  26,\n  27,\n  28,\n  29,\n]\n]")
756    }
757}
arrow_array/array/struct_array.rs

arrow_array/array/
struct_array.rs
