arrow_array/array/
mod.rs

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16// under the License.
17
18//! The concrete array definitions
19
20mod binary_array;
21
22use crate::types::*;
23use arrow_buffer::{ArrowNativeType, NullBuffer, OffsetBuffer, ScalarBuffer};
24use arrow_data::ArrayData;
25use arrow_schema::{DataType, IntervalUnit, TimeUnit};
26use std::any::Any;
27use std::sync::Arc;
28
29pub use binary_array::*;
30
31mod boolean_array;
32pub use boolean_array::*;
33
34mod byte_array;
35pub use byte_array::*;
36
37mod dictionary_array;
38pub use dictionary_array::*;
39
40mod fixed_size_binary_array;
41pub use fixed_size_binary_array::*;
42
43mod fixed_size_list_array;
44pub use fixed_size_list_array::*;
45
46mod list_array;
47pub use list_array::*;
48
49mod map_array;
50pub use map_array::*;
51
52mod null_array;
53pub use null_array::*;
54
55mod primitive_array;
56pub use primitive_array::*;
57
58mod string_array;
59pub use string_array::*;
60
61mod struct_array;
62pub use struct_array::*;
63
64mod union_array;
65pub use union_array::*;
66
67mod run_array;
68
69pub use run_array::*;
70
71mod byte_view_array;
72
73pub use byte_view_array::*;
74
75mod list_view_array;
76
77pub use list_view_array::*;
78
79use crate::iterator::ArrayIter;
80
81/// An array in the [arrow columnar format](https://arrow.apache.org/docs/format/Columnar.html)
82pub trait Array: std::fmt::Debug + Send + Sync {
83    /// Returns the array as [`Any`] so that it can be
84    /// downcasted to a specific implementation.
85    ///
86    /// # Example:
87    ///
88    /// ```
89    /// # use std::sync::Arc;
90    /// # use arrow_array::{Int32Array, RecordBatch};
91    /// # use arrow_schema::{Schema, Field, DataType, ArrowError};
92    ///
93    /// let id = Int32Array::from(vec![1, 2, 3, 4, 5]);
94    /// let batch = RecordBatch::try_new(
95    ///     Arc::new(Schema::new(vec![Field::new("id", DataType::Int32, false)])),
96    ///     vec![Arc::new(id)]
97    /// ).unwrap();
98    ///
99    /// let int32array = batch
100    ///     .column(0)
101    ///     .as_any()
102    ///     .downcast_ref::<Int32Array>()
103    ///     .expect("Failed to downcast");
104    /// ```
105    fn as_any(&self) -> &dyn Any;
106
107    /// Returns the underlying data of this array
108    fn to_data(&self) -> ArrayData;
109
110    /// Returns the underlying data of this array
111    ///
112    /// Unlike [`Array::to_data`] this consumes self, allowing it avoid unnecessary clones
113    fn into_data(self) -> ArrayData;
114
115    /// Returns a reference to the [`DataType`] of this array.
116    ///
117    /// # Example:
118    ///
119    /// ```
120    /// use arrow_schema::DataType;
121    /// use arrow_array::{Array, Int32Array};
122    ///
123    /// let array = Int32Array::from(vec![1, 2, 3, 4, 5]);
124    ///
125    /// assert_eq!(*array.data_type(), DataType::Int32);
126    /// ```
127    fn data_type(&self) -> &DataType;
128
129    /// Returns a zero-copy slice of this array with the indicated offset and length.
130    ///
131    /// # Example:
132    ///
133    /// ```
134    /// use arrow_array::{Array, Int32Array};
135    ///
136    /// let array = Int32Array::from(vec![1, 2, 3, 4, 5]);
137    /// // Make slice over the values [2, 3, 4]
138    /// let array_slice = array.slice(1, 3);
139    ///
140    /// assert_eq!(&array_slice, &Int32Array::from(vec![2, 3, 4]));
141    /// ```
142    fn slice(&self, offset: usize, length: usize) -> ArrayRef;
143
144    /// Returns the length (i.e., number of elements) of this array.
145    ///
146    /// # Example:
147    ///
148    /// ```
149    /// use arrow_array::{Array, Int32Array};
150    ///
151    /// let array = Int32Array::from(vec![1, 2, 3, 4, 5]);
152    ///
153    /// assert_eq!(array.len(), 5);
154    /// ```
155    fn len(&self) -> usize;
156
157    /// Returns whether this array is empty.
158    ///
159    /// # Example:
160    ///
161    /// ```
162    /// use arrow_array::{Array, Int32Array};
163    ///
164    /// let array = Int32Array::from(vec![1, 2, 3, 4, 5]);
165    ///
166    /// assert_eq!(array.is_empty(), false);
167    /// ```
168    fn is_empty(&self) -> bool;
169
170    /// Shrinks the capacity of any exclusively owned buffer as much as possible
171    ///
172    /// Shared or externally allocated buffers will be ignored, and
173    /// any buffer offsets will be preserved.
174    fn shrink_to_fit(&mut self) {}
175
176    /// Returns the offset into the underlying data used by this array(-slice).
177    /// Note that the underlying data can be shared by many arrays.
178    /// This defaults to `0`.
179    ///
180    /// # Example:
181    ///
182    /// ```
183    /// use arrow_array::{Array, BooleanArray};
184    ///
185    /// let array = BooleanArray::from(vec![false, false, true, true]);
186    /// let array_slice = array.slice(1, 3);
187    ///
188    /// assert_eq!(array.offset(), 0);
189    /// assert_eq!(array_slice.offset(), 1);
190    /// ```
191    fn offset(&self) -> usize;
192
193    /// Returns the null buffer of this array if any.
194    ///
195    /// The null buffer contains the "physical" nulls of an array, that is how
196    /// the nulls are represented in the underlying arrow format.
197    ///
198    /// The physical representation is efficient, but is sometimes non intuitive
199    /// for certain array types such as those with nullable child arrays like
200    /// [`DictionaryArray::values`], [`RunArray::values`] or [`UnionArray`], or without a
201    /// null buffer, such as [`NullArray`].
202    ///
203    /// To determine if each element of such an array is "logically" null,
204    /// use the slower [`Array::logical_nulls`] to obtain a computed mask.
205    fn nulls(&self) -> Option<&NullBuffer>;
206
207    /// Returns a potentially computed [`NullBuffer`] that represents the logical
208    /// null values of this array, if any.
209    ///
210    /// Logical nulls represent the values that are null in the array,
211    /// regardless of the underlying physical arrow representation.
212    ///
213    /// For most array types, this is equivalent to the "physical" nulls
214    /// returned by [`Array::nulls`]. It is different for the following cases, because which
215    /// elements are null is not encoded in a single null buffer:
216    ///
217    /// * [`DictionaryArray`] where [`DictionaryArray::values`] contains nulls
218    /// * [`RunArray`] where [`RunArray::values`] contains nulls
219    /// * [`NullArray`] where all indices are nulls
220    /// * [`UnionArray`] where the selected values contains nulls
221    ///
222    /// In these cases a logical [`NullBuffer`] will be computed, encoding the
223    /// logical nullability of these arrays, beyond what is encoded in
224    /// [`Array::nulls`]
225    fn logical_nulls(&self) -> Option<NullBuffer> {
226        self.nulls().cloned()
227    }
228
229    /// Returns whether the element at `index` is null according to [`Array::nulls`]
230    ///
231    /// Note: For performance reasons, this method returns nullability solely as determined by the
232    /// null buffer. This difference can lead to surprising results, for example, [`NullArray::is_null`] always
233    /// returns `false` as the array lacks a null buffer. Similarly [`DictionaryArray`], [`RunArray`] and [`UnionArray`] may
234    /// encode nullability in their children. See [`Self::logical_nulls`] for more information.
235    ///
236    /// # Example:
237    ///
238    /// ```
239    /// use arrow_array::{Array, Int32Array, NullArray};
240    ///
241    /// let array = Int32Array::from(vec![Some(1), None]);
242    /// assert_eq!(array.is_null(0), false);
243    /// assert_eq!(array.is_null(1), true);
244    ///
245    /// // NullArrays do not have a null buffer, and therefore always
246    /// // return false for is_null.
247    /// let array = NullArray::new(1);
248    /// assert_eq!(array.is_null(0), false);
249    /// ```
250    fn is_null(&self, index: usize) -> bool {
251        self.nulls().map(|n| n.is_null(index)).unwrap_or_default()
252    }
253
254    /// Returns whether the element at `index` is *not* null, the
255    /// opposite of [`Self::is_null`].
256    ///
257    /// # Example:
258    ///
259    /// ```
260    /// use arrow_array::{Array, Int32Array};
261    ///
262    /// let array = Int32Array::from(vec![Some(1), None]);
263    ///
264    /// assert_eq!(array.is_valid(0), true);
265    /// assert_eq!(array.is_valid(1), false);
266    /// ```
267    fn is_valid(&self, index: usize) -> bool {
268        !self.is_null(index)
269    }
270
271    /// Returns the total number of physical null values in this array.
272    ///
273    /// Note: this method returns the physical null count, i.e. that encoded in [`Array::nulls`],
274    /// see [`Array::logical_nulls`] for logical nullability
275    ///
276    /// # Example:
277    ///
278    /// ```
279    /// use arrow_array::{Array, Int32Array};
280    ///
281    /// // Construct an array with values [1, NULL, NULL]
282    /// let array = Int32Array::from(vec![Some(1), None, None]);
283    ///
284    /// assert_eq!(array.null_count(), 2);
285    /// ```
286    fn null_count(&self) -> usize {
287        self.nulls().map(|n| n.null_count()).unwrap_or_default()
288    }
289
290    /// Returns the total number of logical null values in this array.
291    ///
292    /// Note: this method returns the logical null count, i.e. that encoded in
293    /// [`Array::logical_nulls`]. In general this is equivalent to [`Array::null_count`] but may differ in the
294    /// presence of logical nullability, see [`Array::nulls`] and [`Array::logical_nulls`].
295    ///
296    /// # Example:
297    ///
298    /// ```
299    /// use arrow_array::{Array, Int32Array};
300    ///
301    /// // Construct an array with values [1, NULL, NULL]
302    /// let array = Int32Array::from(vec![Some(1), None, None]);
303    ///
304    /// assert_eq!(array.logical_null_count(), 2);
305    /// ```
306    fn logical_null_count(&self) -> usize {
307        self.logical_nulls()
308            .map(|n| n.null_count())
309            .unwrap_or_default()
310    }
311
312    /// Returns `false` if the array is guaranteed to not contain any logical nulls
313    ///
314    /// This is generally equivalent to `Array::logical_null_count() != 0` unless determining
315    /// the logical nulls is expensive, in which case this method can return true even for an
316    /// array without nulls.
317    ///
318    /// This is also generally equivalent to `Array::null_count() != 0` but may differ in the
319    /// presence of logical nullability, see [`Array::logical_null_count`] and [`Array::null_count`].
320    ///
321    /// Implementations will return `true` unless they can cheaply prove no logical nulls
322    /// are present. For example a [`DictionaryArray`] with nullable values will still return true,
323    /// even if the nulls present in [`DictionaryArray::values`] are not referenced by any key,
324    /// and therefore would not appear in [`Array::logical_nulls`].
325    fn is_nullable(&self) -> bool {
326        // TODO this is not necessarily perfect default implementation, since null_count() and logical_null_count() are not always equivalent
327        self.null_count() != 0
328    }
329
330    /// Returns the total number of bytes of memory pointed to by this array.
331    /// The buffers store bytes in the Arrow memory format, and include the data as well as the validity map.
332    /// Note that this does not always correspond to the exact memory usage of an array,
333    /// since multiple arrays can share the same buffers or slices thereof.
334    fn get_buffer_memory_size(&self) -> usize;
335
336    /// Returns the total number of bytes of memory occupied physically by this array.
337    /// This value will always be greater than returned by `get_buffer_memory_size()` and
338    /// includes the overhead of the data structures that contain the pointers to the various buffers.
339    fn get_array_memory_size(&self) -> usize;
340}
341
342/// A reference-counted reference to a generic `Array`
343pub type ArrayRef = Arc<dyn Array>;
344
345/// Ergonomics: Allow use of an ArrayRef as an `&dyn Array`
346impl Array for ArrayRef {
347    fn as_any(&self) -> &dyn Any {
348        self.as_ref().as_any()
349    }
350
351    fn to_data(&self) -> ArrayData {
352        self.as_ref().to_data()
353    }
354
355    fn into_data(self) -> ArrayData {
356        self.to_data()
357    }
358
359    fn data_type(&self) -> &DataType {
360        self.as_ref().data_type()
361    }
362
363    fn slice(&self, offset: usize, length: usize) -> ArrayRef {
364        self.as_ref().slice(offset, length)
365    }
366
367    fn len(&self) -> usize {
368        self.as_ref().len()
369    }
370
371    fn is_empty(&self) -> bool {
372        self.as_ref().is_empty()
373    }
374
375    /// For shared buffers, this is a no-op.
376    fn shrink_to_fit(&mut self) {
377        if let Some(slf) = Arc::get_mut(self) {
378            slf.shrink_to_fit();
379        } else {
380            // We ignore shared buffers.
381        }
382    }
383
384    fn offset(&self) -> usize {
385        self.as_ref().offset()
386    }
387
388    fn nulls(&self) -> Option<&NullBuffer> {
389        self.as_ref().nulls()
390    }
391
392    fn logical_nulls(&self) -> Option<NullBuffer> {
393        self.as_ref().logical_nulls()
394    }
395
396    fn is_null(&self, index: usize) -> bool {
397        self.as_ref().is_null(index)
398    }
399
400    fn is_valid(&self, index: usize) -> bool {
401        self.as_ref().is_valid(index)
402    }
403
404    fn null_count(&self) -> usize {
405        self.as_ref().null_count()
406    }
407
408    fn logical_null_count(&self) -> usize {
409        self.as_ref().logical_null_count()
410    }
411
412    fn is_nullable(&self) -> bool {
413        self.as_ref().is_nullable()
414    }
415
416    fn get_buffer_memory_size(&self) -> usize {
417        self.as_ref().get_buffer_memory_size()
418    }
419
420    fn get_array_memory_size(&self) -> usize {
421        self.as_ref().get_array_memory_size()
422    }
423}
424
425impl<T: Array> Array for &T {
426    fn as_any(&self) -> &dyn Any {
427        T::as_any(self)
428    }
429
430    fn to_data(&self) -> ArrayData {
431        T::to_data(self)
432    }
433
434    fn into_data(self) -> ArrayData {
435        self.to_data()
436    }
437
438    fn data_type(&self) -> &DataType {
439        T::data_type(self)
440    }
441
442    fn slice(&self, offset: usize, length: usize) -> ArrayRef {
443        T::slice(self, offset, length)
444    }
445
446    fn len(&self) -> usize {
447        T::len(self)
448    }
449
450    fn is_empty(&self) -> bool {
451        T::is_empty(self)
452    }
453
454    fn offset(&self) -> usize {
455        T::offset(self)
456    }
457
458    fn nulls(&self) -> Option<&NullBuffer> {
459        T::nulls(self)
460    }
461
462    fn logical_nulls(&self) -> Option<NullBuffer> {
463        T::logical_nulls(self)
464    }
465
466    fn is_null(&self, index: usize) -> bool {
467        T::is_null(self, index)
468    }
469
470    fn is_valid(&self, index: usize) -> bool {
471        T::is_valid(self, index)
472    }
473
474    fn null_count(&self) -> usize {
475        T::null_count(self)
476    }
477
478    fn logical_null_count(&self) -> usize {
479        T::logical_null_count(self)
480    }
481
482    fn is_nullable(&self) -> bool {
483        T::is_nullable(self)
484    }
485
486    fn get_buffer_memory_size(&self) -> usize {
487        T::get_buffer_memory_size(self)
488    }
489
490    fn get_array_memory_size(&self) -> usize {
491        T::get_array_memory_size(self)
492    }
493}
494
495/// A generic trait for accessing the values of an [`Array`]
496///
497/// This trait helps write specialized implementations of algorithms for
498/// different array types. Specialized implementations allow the compiler
499/// to optimize the code for the specific array type, which can lead to
500/// significant performance improvements.
501///
502/// # Example
503/// For example, to write three different implementations of a string length function
504/// for [`StringArray`], [`LargeStringArray`], and [`StringViewArray`], you can write
505///
506/// ```
507/// # use std::sync::Arc;
508/// # use arrow_array::{ArrayAccessor, ArrayRef, ArrowPrimitiveType, OffsetSizeTrait, PrimitiveArray};
509/// # use arrow_buffer::ArrowNativeType;
510/// # use arrow_array::cast::AsArray;
511/// # use arrow_array::iterator::ArrayIter;
512/// # use arrow_array::types::{Int32Type, Int64Type};
513/// # use arrow_schema::{ArrowError, DataType};
514/// /// This function takes a dynamically typed `ArrayRef` and calls
515/// /// calls one of three specialized implementations
516/// fn character_length(arg: ArrayRef) -> Result<ArrayRef, ArrowError> {
517///     match arg.data_type() {
518///         DataType::Utf8 => {
519///             // downcast the ArrayRef to a StringArray and call the specialized implementation
520///             let string_array = arg.as_string::<i32>();
521///             character_length_general::<Int32Type, _>(string_array)
522///         }
523///         DataType::LargeUtf8 => {
524///             character_length_general::<Int64Type, _>(arg.as_string::<i64>())
525///         }
526///         DataType::Utf8View => {
527///             character_length_general::<Int32Type, _>(arg.as_string_view())
528///         }
529///         _ => Err(ArrowError::InvalidArgumentError("Unsupported data type".to_string())),
530///     }
531/// }
532///
533/// /// A generic implementation of the character_length function
534/// /// This function uses the `ArrayAccessor` trait to access the values of the array
535/// /// so the compiler can generated specialized implementations for different array types
536/// ///
537/// /// Returns a new array with the length of each string in the input array
538/// /// * Int32Array for Utf8 and Utf8View arrays (lengths are 32-bit integers)
539/// /// * Int64Array for LargeUtf8 arrays (lengths are 64-bit integers)
540/// ///
541/// /// This is generic on the type of the primitive array (different string arrays have
542/// /// different lengths) and the type of the array accessor (different string arrays
543/// /// have different ways to access the values)
544/// fn character_length_general<'a, T: ArrowPrimitiveType, V: ArrayAccessor<Item = &'a str>>(
545///     array: V,
546/// ) -> Result<ArrayRef, ArrowError>
547/// where
548///     T::Native: OffsetSizeTrait,
549/// {
550///     let iter = ArrayIter::new(array);
551///     // Create a Int32Array / Int64Array with the length of each string
552///     let result = iter
553///         .map(|string| {
554///             string.map(|string: &str| {
555///                 T::Native::from_usize(string.chars().count())
556///                     .expect("should not fail as string.chars will always return integer")
557///             })
558///         })
559///         .collect::<PrimitiveArray<T>>();
560///
561///     /// Return the result as a new ArrayRef (dynamically typed)
562///     Ok(Arc::new(result) as ArrayRef)
563/// }
564/// ```
565///
566/// # Validity
567///
568/// An [`ArrayAccessor`] must always return a well-defined value for an index
569/// that is within the bounds `0..Array::len`, including for null indexes where
570/// [`Array::is_null`] is true.
571///
572/// The value at null indexes is unspecified, and implementations must not rely
573/// on a specific value such as [`Default::default`] being returned, however, it
574/// must not be undefined
575pub trait ArrayAccessor: Array {
576    /// The Arrow type of the element being accessed.
577    type Item: Send + Sync;
578
579    /// Returns the element at index `i`
580    /// # Panics
581    /// Panics if the value is outside the bounds of the array
582    fn value(&self, index: usize) -> Self::Item;
583
584    /// Returns the element at index `i`
585    /// # Safety
586    /// Caller is responsible for ensuring that the index is within the bounds of the array
587    unsafe fn value_unchecked(&self, index: usize) -> Self::Item;
588}
589
590/// A trait for Arrow String Arrays, currently three types are supported:
591/// - `StringArray`
592/// - `LargeStringArray`
593/// - `StringViewArray`
594///
595/// This trait helps to abstract over the different types of string arrays
596/// so that we don't need to duplicate the implementation for each type.
597pub trait StringArrayType<'a>: ArrayAccessor<Item = &'a str> + Sized {
598    /// Returns true if all data within this string array is ASCII
599    fn is_ascii(&self) -> bool;
600
601    /// Constructs a new iterator
602    fn iter(&self) -> ArrayIter<Self>;
603}
604
605impl<'a, O: OffsetSizeTrait> StringArrayType<'a> for &'a GenericStringArray<O> {
606    fn is_ascii(&self) -> bool {
607        GenericStringArray::<O>::is_ascii(self)
608    }
609
610    fn iter(&self) -> ArrayIter<Self> {
611        GenericStringArray::<O>::iter(self)
612    }
613}
614impl<'a> StringArrayType<'a> for &'a StringViewArray {
615    fn is_ascii(&self) -> bool {
616        StringViewArray::is_ascii(self)
617    }
618
619    fn iter(&self) -> ArrayIter<Self> {
620        StringViewArray::iter(self)
621    }
622}
623
624impl PartialEq for dyn Array + '_ {
625    fn eq(&self, other: &Self) -> bool {
626        self.to_data().eq(&other.to_data())
627    }
628}
629
630impl<T: Array> PartialEq<T> for dyn Array + '_ {
631    fn eq(&self, other: &T) -> bool {
632        self.to_data().eq(&other.to_data())
633    }
634}
635
636impl PartialEq for NullArray {
637    fn eq(&self, other: &NullArray) -> bool {
638        self.to_data().eq(&other.to_data())
639    }
640}
641
642impl<T: ArrowPrimitiveType> PartialEq for PrimitiveArray<T> {
643    fn eq(&self, other: &PrimitiveArray<T>) -> bool {
644        self.to_data().eq(&other.to_data())
645    }
646}
647
648impl<K: ArrowDictionaryKeyType> PartialEq for DictionaryArray<K> {
649    fn eq(&self, other: &Self) -> bool {
650        self.to_data().eq(&other.to_data())
651    }
652}
653
654impl PartialEq for BooleanArray {
655    fn eq(&self, other: &BooleanArray) -> bool {
656        self.to_data().eq(&other.to_data())
657    }
658}
659
660impl<OffsetSize: OffsetSizeTrait> PartialEq for GenericStringArray<OffsetSize> {
661    fn eq(&self, other: &Self) -> bool {
662        self.to_data().eq(&other.to_data())
663    }
664}
665
666impl<OffsetSize: OffsetSizeTrait> PartialEq for GenericBinaryArray<OffsetSize> {
667    fn eq(&self, other: &Self) -> bool {
668        self.to_data().eq(&other.to_data())
669    }
670}
671
672impl PartialEq for FixedSizeBinaryArray {
673    fn eq(&self, other: &Self) -> bool {
674        self.to_data().eq(&other.to_data())
675    }
676}
677
678impl<OffsetSize: OffsetSizeTrait> PartialEq for GenericListArray<OffsetSize> {
679    fn eq(&self, other: &Self) -> bool {
680        self.to_data().eq(&other.to_data())
681    }
682}
683
684impl<OffsetSize: OffsetSizeTrait> PartialEq for GenericListViewArray<OffsetSize> {
685    fn eq(&self, other: &Self) -> bool {
686        self.to_data().eq(&other.to_data())
687    }
688}
689
690impl PartialEq for MapArray {
691    fn eq(&self, other: &Self) -> bool {
692        self.to_data().eq(&other.to_data())
693    }
694}
695
696impl PartialEq for FixedSizeListArray {
697    fn eq(&self, other: &Self) -> bool {
698        self.to_data().eq(&other.to_data())
699    }
700}
701
702impl PartialEq for StructArray {
703    fn eq(&self, other: &Self) -> bool {
704        self.to_data().eq(&other.to_data())
705    }
706}
707
708impl<T: ByteViewType + ?Sized> PartialEq for GenericByteViewArray<T> {
709    fn eq(&self, other: &Self) -> bool {
710        self.to_data().eq(&other.to_data())
711    }
712}
713
714/// Constructs an array using the input `data`.
715/// Returns a reference-counted `Array` instance.
716pub fn make_array(data: ArrayData) -> ArrayRef {
717    match data.data_type() {
718        DataType::Boolean => Arc::new(BooleanArray::from(data)) as ArrayRef,
719        DataType::Int8 => Arc::new(Int8Array::from(data)) as ArrayRef,
720        DataType::Int16 => Arc::new(Int16Array::from(data)) as ArrayRef,
721        DataType::Int32 => Arc::new(Int32Array::from(data)) as ArrayRef,
722        DataType::Int64 => Arc::new(Int64Array::from(data)) as ArrayRef,
723        DataType::UInt8 => Arc::new(UInt8Array::from(data)) as ArrayRef,
724        DataType::UInt16 => Arc::new(UInt16Array::from(data)) as ArrayRef,
725        DataType::UInt32 => Arc::new(UInt32Array::from(data)) as ArrayRef,
726        DataType::UInt64 => Arc::new(UInt64Array::from(data)) as ArrayRef,
727        DataType::Float16 => Arc::new(Float16Array::from(data)) as ArrayRef,
728        DataType::Float32 => Arc::new(Float32Array::from(data)) as ArrayRef,
729        DataType::Float64 => Arc::new(Float64Array::from(data)) as ArrayRef,
730        DataType::Date32 => Arc::new(Date32Array::from(data)) as ArrayRef,
731        DataType::Date64 => Arc::new(Date64Array::from(data)) as ArrayRef,
732        DataType::Time32(TimeUnit::Second) => Arc::new(Time32SecondArray::from(data)) as ArrayRef,
733        DataType::Time32(TimeUnit::Millisecond) => {
734            Arc::new(Time32MillisecondArray::from(data)) as ArrayRef
735        }
736        DataType::Time64(TimeUnit::Microsecond) => {
737            Arc::new(Time64MicrosecondArray::from(data)) as ArrayRef
738        }
739        DataType::Time64(TimeUnit::Nanosecond) => {
740            Arc::new(Time64NanosecondArray::from(data)) as ArrayRef
741        }
742        DataType::Timestamp(TimeUnit::Second, _) => {
743            Arc::new(TimestampSecondArray::from(data)) as ArrayRef
744        }
745        DataType::Timestamp(TimeUnit::Millisecond, _) => {
746            Arc::new(TimestampMillisecondArray::from(data)) as ArrayRef
747        }
748        DataType::Timestamp(TimeUnit::Microsecond, _) => {
749            Arc::new(TimestampMicrosecondArray::from(data)) as ArrayRef
750        }
751        DataType::Timestamp(TimeUnit::Nanosecond, _) => {
752            Arc::new(TimestampNanosecondArray::from(data)) as ArrayRef
753        }
754        DataType::Interval(IntervalUnit::YearMonth) => {
755            Arc::new(IntervalYearMonthArray::from(data)) as ArrayRef
756        }
757        DataType::Interval(IntervalUnit::DayTime) => {
758            Arc::new(IntervalDayTimeArray::from(data)) as ArrayRef
759        }
760        DataType::Interval(IntervalUnit::MonthDayNano) => {
761            Arc::new(IntervalMonthDayNanoArray::from(data)) as ArrayRef
762        }
763        DataType::Duration(TimeUnit::Second) => {
764            Arc::new(DurationSecondArray::from(data)) as ArrayRef
765        }
766        DataType::Duration(TimeUnit::Millisecond) => {
767            Arc::new(DurationMillisecondArray::from(data)) as ArrayRef
768        }
769        DataType::Duration(TimeUnit::Microsecond) => {
770            Arc::new(DurationMicrosecondArray::from(data)) as ArrayRef
771        }
772        DataType::Duration(TimeUnit::Nanosecond) => {
773            Arc::new(DurationNanosecondArray::from(data)) as ArrayRef
774        }
775        DataType::Binary => Arc::new(BinaryArray::from(data)) as ArrayRef,
776        DataType::LargeBinary => Arc::new(LargeBinaryArray::from(data)) as ArrayRef,
777        DataType::FixedSizeBinary(_) => Arc::new(FixedSizeBinaryArray::from(data)) as ArrayRef,
778        DataType::BinaryView => Arc::new(BinaryViewArray::from(data)) as ArrayRef,
779        DataType::Utf8 => Arc::new(StringArray::from(data)) as ArrayRef,
780        DataType::LargeUtf8 => Arc::new(LargeStringArray::from(data)) as ArrayRef,
781        DataType::Utf8View => Arc::new(StringViewArray::from(data)) as ArrayRef,
782        DataType::List(_) => Arc::new(ListArray::from(data)) as ArrayRef,
783        DataType::LargeList(_) => Arc::new(LargeListArray::from(data)) as ArrayRef,
784        DataType::ListView(_) => Arc::new(ListViewArray::from(data)) as ArrayRef,
785        DataType::LargeListView(_) => Arc::new(LargeListViewArray::from(data)) as ArrayRef,
786        DataType::Struct(_) => Arc::new(StructArray::from(data)) as ArrayRef,
787        DataType::Map(_, _) => Arc::new(MapArray::from(data)) as ArrayRef,
788        DataType::Union(_, _) => Arc::new(UnionArray::from(data)) as ArrayRef,
789        DataType::FixedSizeList(_, _) => Arc::new(FixedSizeListArray::from(data)) as ArrayRef,
790        DataType::Dictionary(ref key_type, _) => match key_type.as_ref() {
791            DataType::Int8 => Arc::new(DictionaryArray::<Int8Type>::from(data)) as ArrayRef,
792            DataType::Int16 => Arc::new(DictionaryArray::<Int16Type>::from(data)) as ArrayRef,
793            DataType::Int32 => Arc::new(DictionaryArray::<Int32Type>::from(data)) as ArrayRef,
794            DataType::Int64 => Arc::new(DictionaryArray::<Int64Type>::from(data)) as ArrayRef,
795            DataType::UInt8 => Arc::new(DictionaryArray::<UInt8Type>::from(data)) as ArrayRef,
796            DataType::UInt16 => Arc::new(DictionaryArray::<UInt16Type>::from(data)) as ArrayRef,
797            DataType::UInt32 => Arc::new(DictionaryArray::<UInt32Type>::from(data)) as ArrayRef,
798            DataType::UInt64 => Arc::new(DictionaryArray::<UInt64Type>::from(data)) as ArrayRef,
799            dt => panic!("Unexpected dictionary key type {dt:?}"),
800        },
801        DataType::RunEndEncoded(ref run_ends_type, _) => match run_ends_type.data_type() {
802            DataType::Int16 => Arc::new(RunArray::<Int16Type>::from(data)) as ArrayRef,
803            DataType::Int32 => Arc::new(RunArray::<Int32Type>::from(data)) as ArrayRef,
804            DataType::Int64 => Arc::new(RunArray::<Int64Type>::from(data)) as ArrayRef,
805            dt => panic!("Unexpected data type for run_ends array {dt:?}"),
806        },
807        DataType::Null => Arc::new(NullArray::from(data)) as ArrayRef,
808        DataType::Decimal128(_, _) => Arc::new(Decimal128Array::from(data)) as ArrayRef,
809        DataType::Decimal256(_, _) => Arc::new(Decimal256Array::from(data)) as ArrayRef,
810        dt => panic!("Unexpected data type {dt:?}"),
811    }
812}
813
814/// Creates a new empty array
815///
816/// ```
817/// use std::sync::Arc;
818/// use arrow_schema::DataType;
819/// use arrow_array::{ArrayRef, Int32Array, new_empty_array};
820///
821/// let empty_array = new_empty_array(&DataType::Int32);
822/// let array: ArrayRef = Arc::new(Int32Array::from(vec![] as Vec<i32>));
823///
824/// assert_eq!(&array, &empty_array);
825/// ```
826pub fn new_empty_array(data_type: &DataType) -> ArrayRef {
827    let data = ArrayData::new_empty(data_type);
828    make_array(data)
829}
830
831/// Creates a new array of `data_type` of length `length` filled
832/// entirely of `NULL` values
833///
834/// ```
835/// use std::sync::Arc;
836/// use arrow_schema::DataType;
837/// use arrow_array::{ArrayRef, Int32Array, new_null_array};
838///
839/// let null_array = new_null_array(&DataType::Int32, 3);
840/// let array: ArrayRef = Arc::new(Int32Array::from(vec![None, None, None]));
841///
842/// assert_eq!(&array, &null_array);
843/// ```
844pub fn new_null_array(data_type: &DataType, length: usize) -> ArrayRef {
845    make_array(ArrayData::new_null(data_type, length))
846}
847
848/// Helper function that gets offset from an [`ArrayData`]
849///
850/// # Safety
851///
852/// - ArrayData must contain a valid [`OffsetBuffer`] as its first buffer
853unsafe fn get_offsets<O: ArrowNativeType>(data: &ArrayData) -> OffsetBuffer<O> {
854    match data.is_empty() && data.buffers()[0].is_empty() {
855        true => OffsetBuffer::new_empty(),
856        false => {
857            let buffer =
858                ScalarBuffer::new(data.buffers()[0].clone(), data.offset(), data.len() + 1);
859            // Safety:
860            // ArrayData is valid
861            unsafe { OffsetBuffer::new_unchecked(buffer) }
862        }
863    }
864}
865
866/// Helper function for printing potentially long arrays.
867fn print_long_array<A, F>(array: &A, f: &mut std::fmt::Formatter, print_item: F) -> std::fmt::Result
868where
869    A: Array,
870    F: Fn(&A, usize, &mut std::fmt::Formatter) -> std::fmt::Result,
871{
872    let head = std::cmp::min(10, array.len());
873
874    for i in 0..head {
875        if array.is_null(i) {
876            writeln!(f, "  null,")?;
877        } else {
878            write!(f, "  ")?;
879            print_item(array, i, f)?;
880            writeln!(f, ",")?;
881        }
882    }
883    if array.len() > 10 {
884        if array.len() > 20 {
885            writeln!(f, "  ...{} elements...,", array.len() - 20)?;
886        }
887
888        let tail = std::cmp::max(head, array.len() - 10);
889
890        for i in tail..array.len() {
891            if array.is_null(i) {
892                writeln!(f, "  null,")?;
893            } else {
894                write!(f, "  ")?;
895                print_item(array, i, f)?;
896                writeln!(f, ",")?;
897            }
898        }
899    }
900    Ok(())
901}
902
903#[cfg(test)]
904mod tests {
905    use super::*;
906    use crate::cast::{as_union_array, downcast_array};
907    use crate::downcast_run_array;
908    use arrow_buffer::MutableBuffer;
909    use arrow_schema::{Field, Fields, UnionFields, UnionMode};
910
911    #[test]
912    fn test_empty_primitive() {
913        let array = new_empty_array(&DataType::Int32);
914        let a = array.as_any().downcast_ref::<Int32Array>().unwrap();
915        assert_eq!(a.len(), 0);
916        let expected: &[i32] = &[];
917        assert_eq!(a.values(), expected);
918    }
919
920    #[test]
921    fn test_empty_variable_sized() {
922        let array = new_empty_array(&DataType::Utf8);
923        let a = array.as_any().downcast_ref::<StringArray>().unwrap();
924        assert_eq!(a.len(), 0);
925        assert_eq!(a.value_offsets()[0], 0i32);
926    }
927
928    #[test]
929    fn test_empty_list_primitive() {
930        let data_type = DataType::List(Arc::new(Field::new("item", DataType::Int32, false)));
931        let array = new_empty_array(&data_type);
932        let a = array.as_any().downcast_ref::<ListArray>().unwrap();
933        assert_eq!(a.len(), 0);
934        assert_eq!(a.value_offsets()[0], 0i32);
935    }
936
937    #[test]
938    fn test_null_boolean() {
939        let array = new_null_array(&DataType::Boolean, 9);
940        let a = array.as_any().downcast_ref::<BooleanArray>().unwrap();
941        assert_eq!(a.len(), 9);
942        for i in 0..9 {
943            assert!(a.is_null(i));
944        }
945    }
946
947    #[test]
948    fn test_null_primitive() {
949        let array = new_null_array(&DataType::Int32, 9);
950        let a = array.as_any().downcast_ref::<Int32Array>().unwrap();
951        assert_eq!(a.len(), 9);
952        for i in 0..9 {
953            assert!(a.is_null(i));
954        }
955    }
956
957    #[test]
958    fn test_null_struct() {
959        // It is possible to create a null struct containing a non-nullable child
960        // see https://github.com/apache/arrow-rs/pull/3244 for details
961        let struct_type = DataType::Struct(vec![Field::new("data", DataType::Int64, false)].into());
962        let array = new_null_array(&struct_type, 9);
963
964        let a = array.as_any().downcast_ref::<StructArray>().unwrap();
965        assert_eq!(a.len(), 9);
966        assert_eq!(a.column(0).len(), 9);
967        for i in 0..9 {
968            assert!(a.is_null(i));
969        }
970
971        // Make sure we can slice the resulting array.
972        a.slice(0, 5);
973    }
974
975    #[test]
976    fn test_null_variable_sized() {
977        let array = new_null_array(&DataType::Utf8, 9);
978        let a = array.as_any().downcast_ref::<StringArray>().unwrap();
979        assert_eq!(a.len(), 9);
980        assert_eq!(a.value_offsets()[9], 0i32);
981        for i in 0..9 {
982            assert!(a.is_null(i));
983        }
984    }
985
986    #[test]
987    fn test_null_list_primitive() {
988        let data_type = DataType::List(Arc::new(Field::new("item", DataType::Int32, true)));
989        let array = new_null_array(&data_type, 9);
990        let a = array.as_any().downcast_ref::<ListArray>().unwrap();
991        assert_eq!(a.len(), 9);
992        assert_eq!(a.value_offsets()[9], 0i32);
993        for i in 0..9 {
994            assert!(a.is_null(i));
995        }
996    }
997
998    #[test]
999    fn test_null_map() {
1000        let data_type = DataType::Map(
1001            Arc::new(Field::new(
1002                "entry",
1003                DataType::Struct(Fields::from(vec![
1004                    Field::new("key", DataType::Utf8, false),
1005                    Field::new("value", DataType::Int32, true),
1006                ])),
1007                false,
1008            )),
1009            false,
1010        );
1011        let array = new_null_array(&data_type, 9);
1012        let a = array.as_any().downcast_ref::<MapArray>().unwrap();
1013        assert_eq!(a.len(), 9);
1014        assert_eq!(a.value_offsets()[9], 0i32);
1015        for i in 0..9 {
1016            assert!(a.is_null(i));
1017        }
1018    }
1019
1020    #[test]
1021    fn test_null_dictionary() {
1022        let values =
1023            vec![None, None, None, None, None, None, None, None, None] as Vec<Option<&str>>;
1024
1025        let array: DictionaryArray<Int8Type> = values.into_iter().collect();
1026        let array = Arc::new(array) as ArrayRef;
1027
1028        let null_array = new_null_array(array.data_type(), 9);
1029        assert_eq!(&array, &null_array);
1030        assert_eq!(
1031            array.to_data().buffers()[0].len(),
1032            null_array.to_data().buffers()[0].len()
1033        );
1034    }
1035
1036    #[test]
1037    fn test_null_union() {
1038        for mode in [UnionMode::Sparse, UnionMode::Dense] {
1039            let data_type = DataType::Union(
1040                UnionFields::new(
1041                    vec![2, 1],
1042                    vec![
1043                        Field::new("foo", DataType::Int32, true),
1044                        Field::new("bar", DataType::Int64, true),
1045                    ],
1046                ),
1047                mode,
1048            );
1049            let array = new_null_array(&data_type, 4);
1050
1051            let array = as_union_array(array.as_ref());
1052            assert_eq!(array.len(), 4);
1053            assert_eq!(array.null_count(), 0);
1054            assert_eq!(array.logical_null_count(), 4);
1055
1056            for i in 0..4 {
1057                let a = array.value(i);
1058                assert_eq!(a.len(), 1);
1059                assert_eq!(a.null_count(), 1);
1060                assert_eq!(a.logical_null_count(), 1);
1061                assert!(a.is_null(0))
1062            }
1063
1064            array.to_data().validate_full().unwrap();
1065        }
1066    }
1067
1068    #[test]
1069    #[allow(unused_parens)]
1070    fn test_null_runs() {
1071        for r in [DataType::Int16, DataType::Int32, DataType::Int64] {
1072            let data_type = DataType::RunEndEncoded(
1073                Arc::new(Field::new("run_ends", r, false)),
1074                Arc::new(Field::new("values", DataType::Utf8, true)),
1075            );
1076
1077            let array = new_null_array(&data_type, 4);
1078            let array = array.as_ref();
1079
1080            downcast_run_array! {
1081                array => {
1082                    assert_eq!(array.len(), 4);
1083                    assert_eq!(array.null_count(), 0);
1084                    assert_eq!(array.logical_null_count(), 4);
1085                    assert_eq!(array.values().len(), 1);
1086                    assert_eq!(array.values().null_count(), 1);
1087                    assert_eq!(array.run_ends().len(), 4);
1088                    assert_eq!(array.run_ends().values(), &[4]);
1089
1090                    let idx = array.get_physical_indices(&[0, 1, 2, 3]).unwrap();
1091                    assert_eq!(idx, &[0,0,0,0]);
1092                }
1093                d => unreachable!("{d}")
1094            }
1095        }
1096    }
1097
1098    #[test]
1099    fn test_null_fixed_size_binary() {
1100        for size in [1, 2, 7] {
1101            let array = new_null_array(&DataType::FixedSizeBinary(size), 6);
1102            let array = array
1103                .as_ref()
1104                .as_any()
1105                .downcast_ref::<FixedSizeBinaryArray>()
1106                .unwrap();
1107
1108            assert_eq!(array.len(), 6);
1109            assert_eq!(array.null_count(), 6);
1110            assert_eq!(array.logical_null_count(), 6);
1111            array.iter().for_each(|x| assert!(x.is_none()));
1112        }
1113    }
1114
1115    #[test]
1116    fn test_memory_size_null() {
1117        let null_arr = NullArray::new(32);
1118
1119        assert_eq!(0, null_arr.get_buffer_memory_size());
1120        assert_eq!(
1121            std::mem::size_of::<usize>(),
1122            null_arr.get_array_memory_size()
1123        );
1124    }
1125
1126    #[test]
1127    fn test_memory_size_primitive() {
1128        let arr = PrimitiveArray::<Int64Type>::from_iter_values(0..128);
1129        let empty = PrimitiveArray::<Int64Type>::from(ArrayData::new_empty(arr.data_type()));
1130
1131        // subtract empty array to avoid magic numbers for the size of additional fields
1132        assert_eq!(
1133            arr.get_array_memory_size() - empty.get_array_memory_size(),
1134            128 * std::mem::size_of::<i64>()
1135        );
1136    }
1137
1138    #[test]
1139    fn test_memory_size_primitive_sliced() {
1140        let arr = PrimitiveArray::<Int64Type>::from_iter_values(0..128);
1141        let slice1 = arr.slice(0, 64);
1142        let slice2 = arr.slice(64, 64);
1143
1144        // both slices report the full buffer memory usage, even though the buffers are shared
1145        assert_eq!(slice1.get_array_memory_size(), arr.get_array_memory_size());
1146        assert_eq!(slice2.get_array_memory_size(), arr.get_array_memory_size());
1147    }
1148
1149    #[test]
1150    fn test_memory_size_primitive_nullable() {
1151        let arr: PrimitiveArray<Int64Type> = (0..128)
1152            .map(|i| if i % 20 == 0 { Some(i) } else { None })
1153            .collect();
1154        let empty_with_bitmap = PrimitiveArray::<Int64Type>::from(
1155            ArrayData::builder(arr.data_type().clone())
1156                .add_buffer(MutableBuffer::new(0).into())
1157                .null_bit_buffer(Some(MutableBuffer::new_null(0).into()))
1158                .build()
1159                .unwrap(),
1160        );
1161
1162        // expected size is the size of the PrimitiveArray struct,
1163        // which includes the optional validity buffer
1164        // plus one buffer on the heap
1165        assert_eq!(
1166            std::mem::size_of::<PrimitiveArray<Int64Type>>(),
1167            empty_with_bitmap.get_array_memory_size()
1168        );
1169
1170        // subtract empty array to avoid magic numbers for the size of additional fields
1171        // the size of the validity bitmap is rounded up to 64 bytes
1172        assert_eq!(
1173            arr.get_array_memory_size() - empty_with_bitmap.get_array_memory_size(),
1174            128 * std::mem::size_of::<i64>() + 64
1175        );
1176    }
1177
1178    #[test]
1179    fn test_memory_size_dictionary() {
1180        let values = PrimitiveArray::<Int64Type>::from_iter_values(0..16);
1181        let keys = PrimitiveArray::<Int16Type>::from_iter_values(
1182            (0..256).map(|i| (i % values.len()) as i16),
1183        );
1184
1185        let dict_data_type = DataType::Dictionary(
1186            Box::new(keys.data_type().clone()),
1187            Box::new(values.data_type().clone()),
1188        );
1189        let dict_data = keys
1190            .into_data()
1191            .into_builder()
1192            .data_type(dict_data_type)
1193            .child_data(vec![values.into_data()])
1194            .build()
1195            .unwrap();
1196
1197        let empty_data = ArrayData::new_empty(&DataType::Dictionary(
1198            Box::new(DataType::Int16),
1199            Box::new(DataType::Int64),
1200        ));
1201
1202        let arr = DictionaryArray::<Int16Type>::from(dict_data);
1203        let empty = DictionaryArray::<Int16Type>::from(empty_data);
1204
1205        let expected_keys_size = 256 * std::mem::size_of::<i16>();
1206        assert_eq!(
1207            arr.keys().get_array_memory_size() - empty.keys().get_array_memory_size(),
1208            expected_keys_size
1209        );
1210
1211        let expected_values_size = 16 * std::mem::size_of::<i64>();
1212        assert_eq!(
1213            arr.values().get_array_memory_size() - empty.values().get_array_memory_size(),
1214            expected_values_size
1215        );
1216
1217        let expected_size = expected_keys_size + expected_values_size;
1218        assert_eq!(
1219            arr.get_array_memory_size() - empty.get_array_memory_size(),
1220            expected_size
1221        );
1222    }
1223
1224    /// Test function that takes an &dyn Array
1225    fn compute_my_thing(arr: &dyn Array) -> bool {
1226        !arr.is_empty()
1227    }
1228
1229    #[test]
1230    fn test_array_ref_as_array() {
1231        let arr: Int32Array = vec![1, 2, 3].into_iter().map(Some).collect();
1232
1233        // works well!
1234        assert!(compute_my_thing(&arr));
1235
1236        // Should also work when wrapped as an ArrayRef
1237        let arr: ArrayRef = Arc::new(arr);
1238        assert!(compute_my_thing(&arr));
1239        assert!(compute_my_thing(arr.as_ref()));
1240    }
1241
1242    #[test]
1243    fn test_downcast_array() {
1244        let array: Int32Array = vec![1, 2, 3].into_iter().map(Some).collect();
1245
1246        let boxed: ArrayRef = Arc::new(array);
1247        let array: Int32Array = downcast_array(&boxed);
1248
1249        let expected: Int32Array = vec![1, 2, 3].into_iter().map(Some).collect();
1250        assert_eq!(array, expected);
1251    }
1252}
arrow_array/array/mod.rs

arrow_array/array/
mod.rs
