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
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
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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        if cfg!(feature = "force_validate") {
193            return Self::new(fields, arrays, nulls);
194        }
195
196        let len = arrays.first().map(|x| x.len()).unwrap_or_default();
197        Self {
198            len,
199            data_type: DataType::Struct(fields),
200            nulls,
201            fields: arrays,
202        }
203    }
204
205    /// Create a new [`StructArray`] containing no fields
206    ///
207    /// # Panics
208    ///
209    /// If `len != nulls.len()`
210    pub fn new_empty_fields(len: usize, nulls: Option<NullBuffer>) -> Self {
211        if let Some(n) = &nulls {
212            assert_eq!(len, n.len())
213        }
214        Self {
215            len,
216            data_type: DataType::Struct(Fields::empty()),
217            fields: vec![],
218            nulls,
219        }
220    }
221
222    /// Deconstruct this array into its constituent parts
223    pub fn into_parts(self) -> (Fields, Vec<ArrayRef>, Option<NullBuffer>) {
224        let f = match self.data_type {
225            DataType::Struct(f) => f,
226            _ => unreachable!(),
227        };
228        (f, self.fields, self.nulls)
229    }
230
231    /// Returns the field at `pos`.
232    pub fn column(&self, pos: usize) -> &ArrayRef {
233        &self.fields[pos]
234    }
235
236    /// Return the number of fields in this struct array
237    pub fn num_columns(&self) -> usize {
238        self.fields.len()
239    }
240
241    /// Returns the fields of the struct array
242    pub fn columns(&self) -> &[ArrayRef] {
243        &self.fields
244    }
245
246    /// Return field names in this struct array
247    pub fn column_names(&self) -> Vec<&str> {
248        match self.data_type() {
249            DataType::Struct(fields) => fields
250                .iter()
251                .map(|f| f.name().as_str())
252                .collect::<Vec<&str>>(),
253            _ => unreachable!("Struct array's data type is not struct!"),
254        }
255    }
256
257    /// Returns the [`Fields`] of this [`StructArray`]
258    pub fn fields(&self) -> &Fields {
259        match self.data_type() {
260            DataType::Struct(f) => f,
261            _ => unreachable!(),
262        }
263    }
264
265    /// Return child array whose field name equals to column_name
266    ///
267    /// Note: A schema can currently have duplicate field names, in which case
268    /// the first field will always be selected.
269    /// This issue will be addressed in [ARROW-11178](https://issues.apache.org/jira/browse/ARROW-11178)
270    pub fn column_by_name(&self, column_name: &str) -> Option<&ArrayRef> {
271        self.column_names()
272            .iter()
273            .position(|c| c == &column_name)
274            .map(|pos| self.column(pos))
275    }
276
277    /// Returns a zero-copy slice of this array with the indicated offset and length.
278    pub fn slice(&self, offset: usize, len: usize) -> Self {
279        assert!(
280            offset.saturating_add(len) <= self.len,
281            "the length + offset of the sliced StructArray cannot exceed the existing length"
282        );
283
284        let fields = self.fields.iter().map(|a| a.slice(offset, len)).collect();
285
286        Self {
287            len,
288            data_type: self.data_type.clone(),
289            nulls: self.nulls.as_ref().map(|n| n.slice(offset, len)),
290            fields,
291        }
292    }
293}
294
295impl From<ArrayData> for StructArray {
296    fn from(data: ArrayData) -> Self {
297        let fields = data
298            .child_data()
299            .iter()
300            .map(|cd| make_array(cd.clone()))
301            .collect();
302
303        Self {
304            len: data.len(),
305            data_type: data.data_type().clone(),
306            nulls: data.nulls().cloned(),
307            fields,
308        }
309    }
310}
311
312impl From<StructArray> for ArrayData {
313    fn from(array: StructArray) -> Self {
314        let builder = ArrayDataBuilder::new(array.data_type)
315            .len(array.len)
316            .nulls(array.nulls)
317            .child_data(array.fields.iter().map(|x| x.to_data()).collect());
318
319        unsafe { builder.build_unchecked() }
320    }
321}
322
323impl TryFrom<Vec<(&str, ArrayRef)>> for StructArray {
324    type Error = ArrowError;
325
326    /// builds a StructArray from a vector of names and arrays.
327    fn try_from(values: Vec<(&str, ArrayRef)>) -> Result<Self, ArrowError> {
328        let (fields, arrays): (Vec<_>, _) = values
329            .into_iter()
330            .map(|(name, array)| {
331                (
332                    Field::new(name, array.data_type().clone(), array.is_nullable()),
333                    array,
334                )
335            })
336            .unzip();
337
338        StructArray::try_new(fields.into(), arrays, None)
339    }
340}
341
342impl Array for StructArray {
343    fn as_any(&self) -> &dyn Any {
344        self
345    }
346
347    fn to_data(&self) -> ArrayData {
348        self.clone().into()
349    }
350
351    fn into_data(self) -> ArrayData {
352        self.into()
353    }
354
355    fn data_type(&self) -> &DataType {
356        &self.data_type
357    }
358
359    fn slice(&self, offset: usize, length: usize) -> ArrayRef {
360        Arc::new(self.slice(offset, length))
361    }
362
363    fn len(&self) -> usize {
364        self.len
365    }
366
367    fn is_empty(&self) -> bool {
368        self.len == 0
369    }
370
371    fn shrink_to_fit(&mut self) {
372        if let Some(nulls) = &mut self.nulls {
373            nulls.shrink_to_fit();
374        }
375        self.fields.iter_mut().for_each(|n| n.shrink_to_fit());
376    }
377
378    fn offset(&self) -> usize {
379        0
380    }
381
382    fn nulls(&self) -> Option<&NullBuffer> {
383        self.nulls.as_ref()
384    }
385
386    fn logical_null_count(&self) -> usize {
387        // More efficient that the default implementation
388        self.null_count()
389    }
390
391    fn get_buffer_memory_size(&self) -> usize {
392        let mut size = self.fields.iter().map(|a| a.get_buffer_memory_size()).sum();
393        if let Some(n) = self.nulls.as_ref() {
394            size += n.buffer().capacity();
395        }
396        size
397    }
398
399    fn get_array_memory_size(&self) -> usize {
400        let mut size = self.fields.iter().map(|a| a.get_array_memory_size()).sum();
401        size += std::mem::size_of::<Self>();
402        if let Some(n) = self.nulls.as_ref() {
403            size += n.buffer().capacity();
404        }
405        size
406    }
407}
408
409impl From<Vec<(FieldRef, ArrayRef)>> for StructArray {
410    fn from(v: Vec<(FieldRef, ArrayRef)>) -> Self {
411        let (fields, arrays): (Vec<_>, _) = v.into_iter().unzip();
412        StructArray::new(fields.into(), arrays, None)
413    }
414}
415
416impl std::fmt::Debug for StructArray {
417    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
418        writeln!(f, "StructArray")?;
419        writeln!(f, "-- validity:")?;
420        writeln!(f, "[")?;
421        print_long_array(self, f, |_array, _index, f| write!(f, "valid"))?;
422        writeln!(f, "]\n[")?;
423        for (child_index, name) in self.column_names().iter().enumerate() {
424            let column = self.column(child_index);
425            writeln!(
426                f,
427                "-- child {}: \"{}\" ({:?})",
428                child_index,
429                name,
430                column.data_type()
431            )?;
432            std::fmt::Debug::fmt(column, f)?;
433            writeln!(f)?;
434        }
435        write!(f, "]")
436    }
437}
438
439impl From<(Vec<(FieldRef, ArrayRef)>, Buffer)> for StructArray {
440    fn from(pair: (Vec<(FieldRef, ArrayRef)>, Buffer)) -> Self {
441        let len = pair.0.first().map(|x| x.1.len()).unwrap_or_default();
442        let (fields, arrays): (Vec<_>, Vec<_>) = pair.0.into_iter().unzip();
443        let nulls = NullBuffer::new(BooleanBuffer::new(pair.1, 0, len));
444        Self::new(fields.into(), arrays, Some(nulls))
445    }
446}
447
448impl From<RecordBatch> for StructArray {
449    fn from(value: RecordBatch) -> Self {
450        Self {
451            len: value.num_rows(),
452            data_type: DataType::Struct(value.schema().fields().clone()),
453            nulls: None,
454            fields: value.columns().to_vec(),
455        }
456    }
457}
458
459impl Index<&str> for StructArray {
460    type Output = ArrayRef;
461
462    /// Get a reference to a column's array by name.
463    ///
464    /// Note: A schema can currently have duplicate field names, in which case
465    /// the first field will always be selected.
466    /// This issue will be addressed in [ARROW-11178](https://issues.apache.org/jira/browse/ARROW-11178)
467    ///
468    /// # Panics
469    ///
470    /// Panics if the name is not in the schema.
471    fn index(&self, name: &str) -> &Self::Output {
472        self.column_by_name(name).unwrap()
473    }
474}
475
476#[cfg(test)]
477mod tests {
478    use super::*;
479
480    use crate::{BooleanArray, Float32Array, Float64Array, Int32Array, Int64Array, StringArray};
481    use arrow_buffer::ToByteSlice;
482
483    #[test]
484    fn test_struct_array_builder() {
485        let boolean_array = BooleanArray::from(vec![false, false, true, true]);
486        let int_array = Int64Array::from(vec![42, 28, 19, 31]);
487
488        let fields = vec![
489            Field::new("a", DataType::Boolean, false),
490            Field::new("b", DataType::Int64, false),
491        ];
492        let struct_array_data = ArrayData::builder(DataType::Struct(fields.into()))
493            .len(4)
494            .add_child_data(boolean_array.to_data())
495            .add_child_data(int_array.to_data())
496            .build()
497            .unwrap();
498        let struct_array = StructArray::from(struct_array_data);
499
500        assert_eq!(struct_array.column(0).as_ref(), &boolean_array);
501        assert_eq!(struct_array.column(1).as_ref(), &int_array);
502    }
503
504    #[test]
505    fn test_struct_array_from() {
506        let boolean = Arc::new(BooleanArray::from(vec![false, false, true, true]));
507        let int = Arc::new(Int32Array::from(vec![42, 28, 19, 31]));
508
509        let struct_array = StructArray::from(vec![
510            (
511                Arc::new(Field::new("b", DataType::Boolean, false)),
512                boolean.clone() as ArrayRef,
513            ),
514            (
515                Arc::new(Field::new("c", DataType::Int32, false)),
516                int.clone() as ArrayRef,
517            ),
518        ]);
519        assert_eq!(struct_array.column(0).as_ref(), boolean.as_ref());
520        assert_eq!(struct_array.column(1).as_ref(), int.as_ref());
521        assert_eq!(4, struct_array.len());
522        assert_eq!(0, struct_array.null_count());
523        assert_eq!(0, struct_array.offset());
524    }
525
526    /// validates that struct can be accessed using `column_name` as index i.e. `struct_array["column_name"]`.
527    #[test]
528    fn test_struct_array_index_access() {
529        let boolean = Arc::new(BooleanArray::from(vec![false, false, true, true]));
530        let int = Arc::new(Int32Array::from(vec![42, 28, 19, 31]));
531
532        let struct_array = StructArray::from(vec![
533            (
534                Arc::new(Field::new("b", DataType::Boolean, false)),
535                boolean.clone() as ArrayRef,
536            ),
537            (
538                Arc::new(Field::new("c", DataType::Int32, false)),
539                int.clone() as ArrayRef,
540            ),
541        ]);
542        assert_eq!(struct_array["b"].as_ref(), boolean.as_ref());
543        assert_eq!(struct_array["c"].as_ref(), int.as_ref());
544    }
545
546    /// validates that the in-memory representation follows [the spec](https://arrow.apache.org/docs/format/Columnar.html#struct-layout)
547    #[test]
548    fn test_struct_array_from_vec() {
549        let strings: ArrayRef = Arc::new(StringArray::from(vec![
550            Some("joe"),
551            None,
552            None,
553            Some("mark"),
554        ]));
555        let ints: ArrayRef = Arc::new(Int32Array::from(vec![Some(1), Some(2), None, Some(4)]));
556
557        let arr =
558            StructArray::try_from(vec![("f1", strings.clone()), ("f2", ints.clone())]).unwrap();
559
560        let struct_data = arr.into_data();
561        assert_eq!(4, struct_data.len());
562        assert_eq!(0, struct_data.null_count());
563
564        let expected_string_data = ArrayData::builder(DataType::Utf8)
565            .len(4)
566            .null_bit_buffer(Some(Buffer::from(&[9_u8])))
567            .add_buffer(Buffer::from([0, 3, 3, 3, 7].to_byte_slice()))
568            .add_buffer(Buffer::from(b"joemark"))
569            .build()
570            .unwrap();
571
572        let expected_int_data = ArrayData::builder(DataType::Int32)
573            .len(4)
574            .null_bit_buffer(Some(Buffer::from(&[11_u8])))
575            .add_buffer(Buffer::from([1, 2, 0, 4].to_byte_slice()))
576            .build()
577            .unwrap();
578
579        assert_eq!(expected_string_data, struct_data.child_data()[0]);
580        assert_eq!(expected_int_data, struct_data.child_data()[1]);
581    }
582
583    #[test]
584    fn test_struct_array_from_vec_error() {
585        let strings: ArrayRef = Arc::new(StringArray::from(vec![
586            Some("joe"),
587            None,
588            None,
589            // 3 elements, not 4
590        ]));
591        let ints: ArrayRef = Arc::new(Int32Array::from(vec![Some(1), Some(2), None, Some(4)]));
592
593        let err = StructArray::try_from(vec![("f1", strings.clone()), ("f2", ints.clone())])
594            .unwrap_err()
595            .to_string();
596
597        assert_eq!(
598            err,
599            "Invalid argument error: Incorrect array length for StructArray field \"f2\", expected 3 got 4"
600        )
601    }
602
603    #[test]
604    #[should_panic(
605        expected = "Incorrect datatype for StructArray field \\\"b\\\", expected Int16 got Boolean"
606    )]
607    fn test_struct_array_from_mismatched_types_single() {
608        drop(StructArray::from(vec![(
609            Arc::new(Field::new("b", DataType::Int16, false)),
610            Arc::new(BooleanArray::from(vec![false, false, true, true])) as Arc<dyn Array>,
611        )]));
612    }
613
614    #[test]
615    #[should_panic(
616        expected = "Incorrect datatype for StructArray field \\\"b\\\", expected Int16 got Boolean"
617    )]
618    fn test_struct_array_from_mismatched_types_multiple() {
619        drop(StructArray::from(vec![
620            (
621                Arc::new(Field::new("b", DataType::Int16, false)),
622                Arc::new(BooleanArray::from(vec![false, false, true, true])) as Arc<dyn Array>,
623            ),
624            (
625                Arc::new(Field::new("c", DataType::Utf8, false)),
626                Arc::new(Int32Array::from(vec![42, 28, 19, 31])),
627            ),
628        ]));
629    }
630
631    #[test]
632    fn test_struct_array_slice() {
633        let boolean_data = ArrayData::builder(DataType::Boolean)
634            .len(5)
635            .add_buffer(Buffer::from([0b00010000]))
636            .null_bit_buffer(Some(Buffer::from([0b00010001])))
637            .build()
638            .unwrap();
639        let int_data = ArrayData::builder(DataType::Int32)
640            .len(5)
641            .add_buffer(Buffer::from([0, 28, 42, 0, 0].to_byte_slice()))
642            .null_bit_buffer(Some(Buffer::from([0b00000110])))
643            .build()
644            .unwrap();
645
646        let field_types = vec![
647            Field::new("a", DataType::Boolean, true),
648            Field::new("b", DataType::Int32, true),
649        ];
650        let struct_array_data = ArrayData::builder(DataType::Struct(field_types.into()))
651            .len(5)
652            .add_child_data(boolean_data.clone())
653            .add_child_data(int_data.clone())
654            .null_bit_buffer(Some(Buffer::from([0b00010111])))
655            .build()
656            .unwrap();
657        let struct_array = StructArray::from(struct_array_data);
658
659        assert_eq!(5, struct_array.len());
660        assert_eq!(1, struct_array.null_count());
661        assert!(struct_array.is_valid(0));
662        assert!(struct_array.is_valid(1));
663        assert!(struct_array.is_valid(2));
664        assert!(struct_array.is_null(3));
665        assert!(struct_array.is_valid(4));
666        assert_eq!(boolean_data, struct_array.column(0).to_data());
667        assert_eq!(int_data, struct_array.column(1).to_data());
668
669        let c0 = struct_array.column(0);
670        let c0 = c0.as_any().downcast_ref::<BooleanArray>().unwrap();
671        assert_eq!(5, c0.len());
672        assert_eq!(3, c0.null_count());
673        assert!(c0.is_valid(0));
674        assert!(!c0.value(0));
675        assert!(c0.is_null(1));
676        assert!(c0.is_null(2));
677        assert!(c0.is_null(3));
678        assert!(c0.is_valid(4));
679        assert!(c0.value(4));
680
681        let c1 = struct_array.column(1);
682        let c1 = c1.as_any().downcast_ref::<Int32Array>().unwrap();
683        assert_eq!(5, c1.len());
684        assert_eq!(3, c1.null_count());
685        assert!(c1.is_null(0));
686        assert!(c1.is_valid(1));
687        assert_eq!(28, c1.value(1));
688        assert!(c1.is_valid(2));
689        assert_eq!(42, c1.value(2));
690        assert!(c1.is_null(3));
691        assert!(c1.is_null(4));
692
693        let sliced_array = struct_array.slice(2, 3);
694        let sliced_array = sliced_array.as_any().downcast_ref::<StructArray>().unwrap();
695        assert_eq!(3, sliced_array.len());
696        assert_eq!(1, sliced_array.null_count());
697        assert!(sliced_array.is_valid(0));
698        assert!(sliced_array.is_null(1));
699        assert!(sliced_array.is_valid(2));
700
701        let sliced_c0 = sliced_array.column(0);
702        let sliced_c0 = sliced_c0.as_any().downcast_ref::<BooleanArray>().unwrap();
703        assert_eq!(3, sliced_c0.len());
704        assert!(sliced_c0.is_null(0));
705        assert!(sliced_c0.is_null(1));
706        assert!(sliced_c0.is_valid(2));
707        assert!(sliced_c0.value(2));
708
709        let sliced_c1 = sliced_array.column(1);
710        let sliced_c1 = sliced_c1.as_any().downcast_ref::<Int32Array>().unwrap();
711        assert_eq!(3, sliced_c1.len());
712        assert!(sliced_c1.is_valid(0));
713        assert_eq!(42, sliced_c1.value(0));
714        assert!(sliced_c1.is_null(1));
715        assert!(sliced_c1.is_null(2));
716    }
717
718    #[test]
719    #[should_panic(
720        expected = "Incorrect array length for StructArray field \\\"c\\\", expected 1 got 2"
721    )]
722    fn test_invalid_struct_child_array_lengths() {
723        drop(StructArray::from(vec![
724            (
725                Arc::new(Field::new("b", DataType::Float32, false)),
726                Arc::new(Float32Array::from(vec![1.1])) as Arc<dyn Array>,
727            ),
728            (
729                Arc::new(Field::new("c", DataType::Float64, false)),
730                Arc::new(Float64Array::from(vec![2.2, 3.3])),
731            ),
732        ]));
733    }
734
735    #[test]
736    fn test_struct_array_from_empty() {
737        let sa = StructArray::from(vec![]);
738        assert!(sa.is_empty())
739    }
740
741    #[test]
742    #[should_panic(expected = "Found unmasked nulls for non-nullable StructArray field \\\"c\\\"")]
743    fn test_struct_array_from_mismatched_nullability() {
744        drop(StructArray::from(vec![(
745            Arc::new(Field::new("c", DataType::Int32, false)),
746            Arc::new(Int32Array::from(vec![Some(42), None, Some(19)])) as ArrayRef,
747        )]));
748    }
749
750    #[test]
751    fn test_struct_array_fmt_debug() {
752        let arr: StructArray = StructArray::new(
753            vec![Arc::new(Field::new("c", DataType::Int32, true))].into(),
754            vec![Arc::new(Int32Array::from((0..30).collect::<Vec<_>>())) as ArrayRef],
755            Some(NullBuffer::new(BooleanBuffer::from(
756                (0..30).map(|i| i % 2 == 0).collect::<Vec<_>>(),
757            ))),
758        );
759        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]")
760    }
761}
arrow_array/array/struct_array.rs

arrow_array/array/
struct_array.rs
