arrow_array/array/
struct_array.rs

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1// Licensed to the Apache Software Foundation (ASF) under one
2// or more contributor license agreements.  See the NOTICE file
3// distributed with this work for additional information
4// regarding copyright ownership.  The ASF licenses this file
5// to you under the Apache License, Version 2.0 (the
6// "License"); you may not use this file except in compliance
7// with the License.  You may obtain a copy of the License at
8//
9//   http://www.apache.org/licenses/LICENSE-2.0
10//
11// Unless required by applicable law or agreed to in writing,
12// software distributed under the License is distributed on an
13// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
14// KIND, either express or implied.  See the License for the
15// specific language governing permissions and limitations
16// under the License.
17
18use crate::array::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    /// Returns child array refs of the struct array
243    #[deprecated(note = "Use columns().to_vec()")]
244    pub fn columns_ref(&self) -> Vec<ArrayRef> {
245        self.columns().to_vec()
246    }
247
248    /// Return field names in this struct array
249    pub fn column_names(&self) -> Vec<&str> {
250        match self.data_type() {
251            DataType::Struct(fields) => fields
252                .iter()
253                .map(|f| f.name().as_str())
254                .collect::<Vec<&str>>(),
255            _ => unreachable!("Struct array's data type is not struct!"),
256        }
257    }
258
259    /// Returns the [`Fields`] of this [`StructArray`]
260    pub fn fields(&self) -> &Fields {
261        match self.data_type() {
262            DataType::Struct(f) => f,
263            _ => unreachable!(),
264        }
265    }
266
267    /// Return child array whose field name equals to column_name
268    ///
269    /// Note: A schema can currently have duplicate field names, in which case
270    /// the first field will always be selected.
271    /// This issue will be addressed in [ARROW-11178](https://issues.apache.org/jira/browse/ARROW-11178)
272    pub fn column_by_name(&self, column_name: &str) -> Option<&ArrayRef> {
273        self.column_names()
274            .iter()
275            .position(|c| c == &column_name)
276            .map(|pos| self.column(pos))
277    }
278
279    /// Returns a zero-copy slice of this array with the indicated offset and length.
280    pub fn slice(&self, offset: usize, len: usize) -> Self {
281        assert!(
282            offset.saturating_add(len) <= self.len,
283            "the length + offset of the sliced StructArray cannot exceed the existing length"
284        );
285
286        let fields = self.fields.iter().map(|a| a.slice(offset, len)).collect();
287
288        Self {
289            len,
290            data_type: self.data_type.clone(),
291            nulls: self.nulls.as_ref().map(|n| n.slice(offset, len)),
292            fields,
293        }
294    }
295}
296
297impl From<ArrayData> for StructArray {
298    fn from(data: ArrayData) -> Self {
299        let fields = data
300            .child_data()
301            .iter()
302            .map(|cd| make_array(cd.clone()))
303            .collect();
304
305        Self {
306            len: data.len(),
307            data_type: data.data_type().clone(),
308            nulls: data.nulls().cloned(),
309            fields,
310        }
311    }
312}
313
314impl From<StructArray> for ArrayData {
315    fn from(array: StructArray) -> Self {
316        let builder = ArrayDataBuilder::new(array.data_type)
317            .len(array.len)
318            .nulls(array.nulls)
319            .child_data(array.fields.iter().map(|x| x.to_data()).collect());
320
321        unsafe { builder.build_unchecked() }
322    }
323}
324
325impl TryFrom<Vec<(&str, ArrayRef)>> for StructArray {
326    type Error = ArrowError;
327
328    /// builds a StructArray from a vector of names and arrays.
329    fn try_from(values: Vec<(&str, ArrayRef)>) -> Result<Self, ArrowError> {
330        let (fields, arrays): (Vec<_>, _) = values
331            .into_iter()
332            .map(|(name, array)| {
333                (
334                    Field::new(name, array.data_type().clone(), array.is_nullable()),
335                    array,
336                )
337            })
338            .unzip();
339
340        StructArray::try_new(fields.into(), arrays, None)
341    }
342}
343
344impl Array for StructArray {
345    fn as_any(&self) -> &dyn Any {
346        self
347    }
348
349    fn to_data(&self) -> ArrayData {
350        self.clone().into()
351    }
352
353    fn into_data(self) -> ArrayData {
354        self.into()
355    }
356
357    fn data_type(&self) -> &DataType {
358        &self.data_type
359    }
360
361    fn slice(&self, offset: usize, length: usize) -> ArrayRef {
362        Arc::new(self.slice(offset, length))
363    }
364
365    fn len(&self) -> usize {
366        self.len
367    }
368
369    fn is_empty(&self) -> bool {
370        self.len == 0
371    }
372
373    fn offset(&self) -> usize {
374        0
375    }
376
377    fn nulls(&self) -> Option<&NullBuffer> {
378        self.nulls.as_ref()
379    }
380
381    fn logical_null_count(&self) -> usize {
382        // More efficient that the default implementation
383        self.null_count()
384    }
385
386    fn get_buffer_memory_size(&self) -> usize {
387        let mut size = self.fields.iter().map(|a| a.get_buffer_memory_size()).sum();
388        if let Some(n) = self.nulls.as_ref() {
389            size += n.buffer().capacity();
390        }
391        size
392    }
393
394    fn get_array_memory_size(&self) -> usize {
395        let mut size = self.fields.iter().map(|a| a.get_array_memory_size()).sum();
396        size += std::mem::size_of::<Self>();
397        if let Some(n) = self.nulls.as_ref() {
398            size += n.buffer().capacity();
399        }
400        size
401    }
402}
403
404impl From<Vec<(FieldRef, ArrayRef)>> for StructArray {
405    fn from(v: Vec<(FieldRef, ArrayRef)>) -> Self {
406        let (fields, arrays): (Vec<_>, _) = v.into_iter().unzip();
407        StructArray::new(fields.into(), arrays, None)
408    }
409}
410
411impl std::fmt::Debug for StructArray {
412    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
413        writeln!(f, "StructArray")?;
414        writeln!(f, "-- validity: ")?;
415        writeln!(f, "[")?;
416        print_long_array(self, f, |_array, _index, f| write!(f, "valid"))?;
417        writeln!(f, "]\n[")?;
418        for (child_index, name) in self.column_names().iter().enumerate() {
419            let column = self.column(child_index);
420            writeln!(
421                f,
422                "-- child {}: \"{}\" ({:?})",
423                child_index,
424                name,
425                column.data_type()
426            )?;
427            std::fmt::Debug::fmt(column, f)?;
428            writeln!(f)?;
429        }
430        write!(f, "]")
431    }
432}
433
434impl From<(Vec<(FieldRef, ArrayRef)>, Buffer)> for StructArray {
435    fn from(pair: (Vec<(FieldRef, ArrayRef)>, Buffer)) -> Self {
436        let len = pair.0.first().map(|x| x.1.len()).unwrap_or_default();
437        let (fields, arrays): (Vec<_>, Vec<_>) = pair.0.into_iter().unzip();
438        let nulls = NullBuffer::new(BooleanBuffer::new(pair.1, 0, len));
439        Self::new(fields.into(), arrays, Some(nulls))
440    }
441}
442
443impl From<RecordBatch> for StructArray {
444    fn from(value: RecordBatch) -> Self {
445        Self {
446            len: value.num_rows(),
447            data_type: DataType::Struct(value.schema().fields().clone()),
448            nulls: None,
449            fields: value.columns().to_vec(),
450        }
451    }
452}
453
454impl Index<&str> for StructArray {
455    type Output = ArrayRef;
456
457    /// Get a reference to a column's array by name.
458    ///
459    /// Note: A schema can currently have duplicate field names, in which case
460    /// the first field will always be selected.
461    /// This issue will be addressed in [ARROW-11178](https://issues.apache.org/jira/browse/ARROW-11178)
462    ///
463    /// # Panics
464    ///
465    /// Panics if the name is not in the schema.
466    fn index(&self, name: &str) -> &Self::Output {
467        self.column_by_name(name).unwrap()
468    }
469}
470
471#[cfg(test)]
472mod tests {
473    use super::*;
474
475    use crate::{BooleanArray, Float32Array, Float64Array, Int32Array, Int64Array, StringArray};
476    use arrow_buffer::ToByteSlice;
477
478    #[test]
479    fn test_struct_array_builder() {
480        let boolean_array = BooleanArray::from(vec![false, false, true, true]);
481        let int_array = Int64Array::from(vec![42, 28, 19, 31]);
482
483        let fields = vec![
484            Field::new("a", DataType::Boolean, false),
485            Field::new("b", DataType::Int64, false),
486        ];
487        let struct_array_data = ArrayData::builder(DataType::Struct(fields.into()))
488            .len(4)
489            .add_child_data(boolean_array.to_data())
490            .add_child_data(int_array.to_data())
491            .build()
492            .unwrap();
493        let struct_array = StructArray::from(struct_array_data);
494
495        assert_eq!(struct_array.column(0).as_ref(), &boolean_array);
496        assert_eq!(struct_array.column(1).as_ref(), &int_array);
497    }
498
499    #[test]
500    fn test_struct_array_from() {
501        let boolean = Arc::new(BooleanArray::from(vec![false, false, true, true]));
502        let int = Arc::new(Int32Array::from(vec![42, 28, 19, 31]));
503
504        let struct_array = StructArray::from(vec![
505            (
506                Arc::new(Field::new("b", DataType::Boolean, false)),
507                boolean.clone() as ArrayRef,
508            ),
509            (
510                Arc::new(Field::new("c", DataType::Int32, false)),
511                int.clone() as ArrayRef,
512            ),
513        ]);
514        assert_eq!(struct_array.column(0).as_ref(), boolean.as_ref());
515        assert_eq!(struct_array.column(1).as_ref(), int.as_ref());
516        assert_eq!(4, struct_array.len());
517        assert_eq!(0, struct_array.null_count());
518        assert_eq!(0, struct_array.offset());
519    }
520
521    /// validates that struct can be accessed using `column_name` as index i.e. `struct_array["column_name"]`.
522    #[test]
523    fn test_struct_array_index_access() {
524        let boolean = Arc::new(BooleanArray::from(vec![false, false, true, true]));
525        let int = Arc::new(Int32Array::from(vec![42, 28, 19, 31]));
526
527        let struct_array = StructArray::from(vec![
528            (
529                Arc::new(Field::new("b", DataType::Boolean, false)),
530                boolean.clone() as ArrayRef,
531            ),
532            (
533                Arc::new(Field::new("c", DataType::Int32, false)),
534                int.clone() as ArrayRef,
535            ),
536        ]);
537        assert_eq!(struct_array["b"].as_ref(), boolean.as_ref());
538        assert_eq!(struct_array["c"].as_ref(), int.as_ref());
539    }
540
541    /// validates that the in-memory representation follows [the spec](https://arrow.apache.org/docs/format/Columnar.html#struct-layout)
542    #[test]
543    fn test_struct_array_from_vec() {
544        let strings: ArrayRef = Arc::new(StringArray::from(vec![
545            Some("joe"),
546            None,
547            None,
548            Some("mark"),
549        ]));
550        let ints: ArrayRef = Arc::new(Int32Array::from(vec![Some(1), Some(2), None, Some(4)]));
551
552        let arr =
553            StructArray::try_from(vec![("f1", strings.clone()), ("f2", ints.clone())]).unwrap();
554
555        let struct_data = arr.into_data();
556        assert_eq!(4, struct_data.len());
557        assert_eq!(0, struct_data.null_count());
558
559        let expected_string_data = ArrayData::builder(DataType::Utf8)
560            .len(4)
561            .null_bit_buffer(Some(Buffer::from(&[9_u8])))
562            .add_buffer(Buffer::from([0, 3, 3, 3, 7].to_byte_slice()))
563            .add_buffer(Buffer::from(b"joemark"))
564            .build()
565            .unwrap();
566
567        let expected_int_data = ArrayData::builder(DataType::Int32)
568            .len(4)
569            .null_bit_buffer(Some(Buffer::from(&[11_u8])))
570            .add_buffer(Buffer::from([1, 2, 0, 4].to_byte_slice()))
571            .build()
572            .unwrap();
573
574        assert_eq!(expected_string_data, struct_data.child_data()[0]);
575        assert_eq!(expected_int_data, struct_data.child_data()[1]);
576    }
577
578    #[test]
579    fn test_struct_array_from_vec_error() {
580        let strings: ArrayRef = Arc::new(StringArray::from(vec![
581            Some("joe"),
582            None,
583            None,
584            // 3 elements, not 4
585        ]));
586        let ints: ArrayRef = Arc::new(Int32Array::from(vec![Some(1), Some(2), None, Some(4)]));
587
588        let err = StructArray::try_from(vec![("f1", strings.clone()), ("f2", ints.clone())])
589            .unwrap_err()
590            .to_string();
591
592        assert_eq!(
593            err,
594            "Invalid argument error: Incorrect array length for StructArray field \"f2\", expected 3 got 4"
595        )
596    }
597
598    #[test]
599    #[should_panic(
600        expected = "Incorrect datatype for StructArray field \\\"b\\\", expected Int16 got Boolean"
601    )]
602    fn test_struct_array_from_mismatched_types_single() {
603        drop(StructArray::from(vec![(
604            Arc::new(Field::new("b", DataType::Int16, false)),
605            Arc::new(BooleanArray::from(vec![false, false, true, true])) as Arc<dyn Array>,
606        )]));
607    }
608
609    #[test]
610    #[should_panic(
611        expected = "Incorrect datatype for StructArray field \\\"b\\\", expected Int16 got Boolean"
612    )]
613    fn test_struct_array_from_mismatched_types_multiple() {
614        drop(StructArray::from(vec![
615            (
616                Arc::new(Field::new("b", DataType::Int16, false)),
617                Arc::new(BooleanArray::from(vec![false, false, true, true])) as Arc<dyn Array>,
618            ),
619            (
620                Arc::new(Field::new("c", DataType::Utf8, false)),
621                Arc::new(Int32Array::from(vec![42, 28, 19, 31])),
622            ),
623        ]));
624    }
625
626    #[test]
627    fn test_struct_array_slice() {
628        let boolean_data = ArrayData::builder(DataType::Boolean)
629            .len(5)
630            .add_buffer(Buffer::from([0b00010000]))
631            .null_bit_buffer(Some(Buffer::from([0b00010001])))
632            .build()
633            .unwrap();
634        let int_data = ArrayData::builder(DataType::Int32)
635            .len(5)
636            .add_buffer(Buffer::from([0, 28, 42, 0, 0].to_byte_slice()))
637            .null_bit_buffer(Some(Buffer::from([0b00000110])))
638            .build()
639            .unwrap();
640
641        let field_types = vec![
642            Field::new("a", DataType::Boolean, true),
643            Field::new("b", DataType::Int32, true),
644        ];
645        let struct_array_data = ArrayData::builder(DataType::Struct(field_types.into()))
646            .len(5)
647            .add_child_data(boolean_data.clone())
648            .add_child_data(int_data.clone())
649            .null_bit_buffer(Some(Buffer::from([0b00010111])))
650            .build()
651            .unwrap();
652        let struct_array = StructArray::from(struct_array_data);
653
654        assert_eq!(5, struct_array.len());
655        assert_eq!(1, struct_array.null_count());
656        assert!(struct_array.is_valid(0));
657        assert!(struct_array.is_valid(1));
658        assert!(struct_array.is_valid(2));
659        assert!(struct_array.is_null(3));
660        assert!(struct_array.is_valid(4));
661        assert_eq!(boolean_data, struct_array.column(0).to_data());
662        assert_eq!(int_data, struct_array.column(1).to_data());
663
664        let c0 = struct_array.column(0);
665        let c0 = c0.as_any().downcast_ref::<BooleanArray>().unwrap();
666        assert_eq!(5, c0.len());
667        assert_eq!(3, c0.null_count());
668        assert!(c0.is_valid(0));
669        assert!(!c0.value(0));
670        assert!(c0.is_null(1));
671        assert!(c0.is_null(2));
672        assert!(c0.is_null(3));
673        assert!(c0.is_valid(4));
674        assert!(c0.value(4));
675
676        let c1 = struct_array.column(1);
677        let c1 = c1.as_any().downcast_ref::<Int32Array>().unwrap();
678        assert_eq!(5, c1.len());
679        assert_eq!(3, c1.null_count());
680        assert!(c1.is_null(0));
681        assert!(c1.is_valid(1));
682        assert_eq!(28, c1.value(1));
683        assert!(c1.is_valid(2));
684        assert_eq!(42, c1.value(2));
685        assert!(c1.is_null(3));
686        assert!(c1.is_null(4));
687
688        let sliced_array = struct_array.slice(2, 3);
689        let sliced_array = sliced_array.as_any().downcast_ref::<StructArray>().unwrap();
690        assert_eq!(3, sliced_array.len());
691        assert_eq!(1, sliced_array.null_count());
692        assert!(sliced_array.is_valid(0));
693        assert!(sliced_array.is_null(1));
694        assert!(sliced_array.is_valid(2));
695
696        let sliced_c0 = sliced_array.column(0);
697        let sliced_c0 = sliced_c0.as_any().downcast_ref::<BooleanArray>().unwrap();
698        assert_eq!(3, sliced_c0.len());
699        assert!(sliced_c0.is_null(0));
700        assert!(sliced_c0.is_null(1));
701        assert!(sliced_c0.is_valid(2));
702        assert!(sliced_c0.value(2));
703
704        let sliced_c1 = sliced_array.column(1);
705        let sliced_c1 = sliced_c1.as_any().downcast_ref::<Int32Array>().unwrap();
706        assert_eq!(3, sliced_c1.len());
707        assert!(sliced_c1.is_valid(0));
708        assert_eq!(42, sliced_c1.value(0));
709        assert!(sliced_c1.is_null(1));
710        assert!(sliced_c1.is_null(2));
711    }
712
713    #[test]
714    #[should_panic(
715        expected = "Incorrect array length for StructArray field \\\"c\\\", expected 1 got 2"
716    )]
717    fn test_invalid_struct_child_array_lengths() {
718        drop(StructArray::from(vec![
719            (
720                Arc::new(Field::new("b", DataType::Float32, false)),
721                Arc::new(Float32Array::from(vec![1.1])) as Arc<dyn Array>,
722            ),
723            (
724                Arc::new(Field::new("c", DataType::Float64, false)),
725                Arc::new(Float64Array::from(vec![2.2, 3.3])),
726            ),
727        ]));
728    }
729
730    #[test]
731    fn test_struct_array_from_empty() {
732        let sa = StructArray::from(vec![]);
733        assert!(sa.is_empty())
734    }
735
736    #[test]
737    #[should_panic(expected = "Found unmasked nulls for non-nullable StructArray field \\\"c\\\"")]
738    fn test_struct_array_from_mismatched_nullability() {
739        drop(StructArray::from(vec![(
740            Arc::new(Field::new("c", DataType::Int32, false)),
741            Arc::new(Int32Array::from(vec![Some(42), None, Some(19)])) as ArrayRef,
742        )]));
743    }
744
745    #[test]
746    fn test_struct_array_fmt_debug() {
747        let arr: StructArray = StructArray::new(
748            vec![Arc::new(Field::new("c", DataType::Int32, true))].into(),
749            vec![Arc::new(Int32Array::from((0..30).collect::<Vec<_>>())) as ArrayRef],
750            Some(NullBuffer::new(BooleanBuffer::from(
751                (0..30).map(|i| i % 2 == 0).collect::<Vec<_>>(),
752            ))),
753        );
754        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]")
755    }
756}
arrow_array/array/struct_array.rs

arrow_array/array/
struct_array.rs
