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arrow_select/
filter.rs

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2// or more contributor license agreements.  See the NOTICE file
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5// to you under the Apache License, Version 2.0 (the
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8//
9//   http://www.apache.org/licenses/LICENSE-2.0
10//
11// Unless required by applicable law or agreed to in writing,
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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
18//! Defines filter kernels
19
20use std::ops::AddAssign;
21use std::sync::Arc;
22
23use arrow_array::builder::BooleanBufferBuilder;
24use arrow_array::cast::AsArray;
25use arrow_array::types::{
26    ArrowDictionaryKeyType, ArrowPrimitiveType, ByteArrayType, ByteViewType, RunEndIndexType,
27};
28use arrow_array::*;
29use arrow_buffer::{
30    ArrowNativeType, BooleanBuffer, NullBuffer, OffsetBuffer, RunEndBuffer, ScalarBuffer, bit_util,
31};
32use arrow_buffer::{Buffer, MutableBuffer};
33use arrow_data::bit_iterator::{BitIndexIterator, BitSliceIterator};
34use arrow_data::transform::MutableArrayData;
35use arrow_schema::*;
36
37/// If the filter selects more than this fraction of rows, use
38/// [`SlicesIterator`] to copy ranges of values. Otherwise iterate
39/// over individual rows using [`IndexIterator`]
40///
41/// Threshold of 0.8 chosen based on <https://dl.acm.org/doi/abs/10.1145/3465998.3466009>
42///
43const FILTER_SLICES_SELECTIVITY_THRESHOLD: f64 = 0.8;
44
45/// An iterator of `(usize, usize)` each representing an interval
46/// `[start, end)` whose slots of a bitmap [Buffer] are true.
47///
48/// Each interval corresponds to a contiguous region of memory to be
49/// "taken" from an array to be filtered.
50///
51/// ## Notes:
52///
53/// 1. Ignores the validity bitmap (ignores nulls)
54///
55/// 2. Only performant for filters that copy across long contiguous runs
56#[derive(Debug)]
57pub struct SlicesIterator<'a>(BitSliceIterator<'a>);
58
59impl<'a> SlicesIterator<'a> {
60    /// Creates a new iterator from a [BooleanArray]
61    pub fn new(filter: &'a BooleanArray) -> Self {
62        filter.values().into()
63    }
64}
65
66impl<'a> From<&'a BooleanBuffer> for SlicesIterator<'a> {
67    fn from(filter: &'a BooleanBuffer) -> Self {
68        Self(filter.set_slices())
69    }
70}
71
72impl Iterator for SlicesIterator<'_> {
73    type Item = (usize, usize);
74
75    fn next(&mut self) -> Option<Self::Item> {
76        self.0.next()
77    }
78}
79
80/// An iterator of `usize` whose index in [`BooleanArray`] is true
81///
82/// This provides the best performance on most predicates, apart from those which keep
83/// large runs and therefore favour [`SlicesIterator`]
84pub(crate) struct IndexIterator<'a> {
85    remaining: usize,
86    iter: BitIndexIterator<'a>,
87}
88
89impl<'a> IndexIterator<'a> {
90    pub(crate) fn new(filter: &'a BooleanArray, remaining: usize) -> Self {
91        assert_eq!(filter.null_count(), 0);
92        let iter = filter.values().set_indices();
93        Self { remaining, iter }
94    }
95
96    /// Collect this iterator as a [`Vec`]
97    /// This is more efficient than the standard `collect` as we can
98    /// pre-allocate the entire uninitialized buffer and then fill it (roughly 1.6x faster)
99    pub fn collect(mut self) -> Vec<usize> {
100        let len = self.remaining;
101        let mut result = Vec::with_capacity(len);
102        let ptr: *mut usize = result.as_mut_ptr();
103        for i in 0..len {
104            // SAFETY: we have allocated enough space in `result` and remaining
105            // correctly tracks the number of elements
106            let next = self.iter.next();
107            debug_assert!(next.is_some(), "IndexIterator exhausted early");
108            unsafe {
109                *ptr.add(i) = next.unwrap_unchecked();
110            }
111        }
112        // SAFETY: we have initialized `len` elements
113        unsafe {
114            result.set_len(len);
115        }
116        result
117    }
118}
119
120impl Iterator for IndexIterator<'_> {
121    type Item = usize;
122
123    fn next(&mut self) -> Option<Self::Item> {
124        if self.remaining != 0 {
125            // Fascinatingly swapping these two lines around results in a 50%
126            // performance regression for some benchmarks
127            let next = self.iter.next().expect("IndexIterator exhausted early");
128            self.remaining -= 1;
129            // Must panic if exhausted early as trusted length iterator
130            return Some(next);
131        }
132        None
133    }
134
135    fn size_hint(&self) -> (usize, Option<usize>) {
136        (self.remaining, Some(self.remaining))
137    }
138}
139
140/// Convert all null values in `BooleanArray` to `false`
141///
142/// This is useful for filter-like operations which select only `true`
143/// values, but not `false` or `NULL` values
144///
145/// Internally this is implemented as a bitwise `AND` operation with null bits
146/// and the boolean bits.
147///
148/// # Example
149/// ```
150/// # use arrow_array::{Array, BooleanArray};
151/// # use arrow_select::filter::prep_null_mask_filter;
152/// let filter = BooleanArray::from(vec![
153///   Some(true),
154///   Some(false),
155///   None
156/// ]);
157/// // convert Boolean array to a filter mask
158/// let null_mask = prep_null_mask_filter(&filter);
159/// // there are no nulls in the output mask
160/// assert!(null_mask.nulls().is_none());
161/// assert_eq!(null_mask, BooleanArray::from(vec![
162///  true,
163///  false,
164///  false, // Null is converted to false
165/// ]));
166/// ```
167pub fn prep_null_mask_filter(filter: &BooleanArray) -> BooleanArray {
168    let nulls = filter.nulls().unwrap();
169    let mask = filter.values() & nulls.inner();
170    BooleanArray::new(mask, None)
171}
172
173/// Returns a filtered `values` [`Array`] where the corresponding elements of
174/// `predicate` are `true`.
175///
176/// If multiple arrays (or record batches) need to be filtered using the same predicate array,
177/// consider using [FilterBuilder] to create a single [FilterPredicate] and then
178/// calling [FilterPredicate::filter_record_batch].
179///
180/// In contrast to this function, it is then the responsibility of the caller
181/// to use [FilterBuilder::optimize] if appropriate.
182///
183/// # See also
184/// * [`FilterBuilder`] for more control over the filtering process.
185/// * [`filter_record_batch`] to filter a [`RecordBatch`]
186/// * [`BatchCoalescer`]: to filter multiple [`RecordBatch`] and coalesce
187///   the results into a single array.
188///
189/// [`BatchCoalescer`]: crate::coalesce::BatchCoalescer
190///
191/// # Example
192/// ```rust
193/// # use arrow_array::{Int32Array, BooleanArray};
194/// # use arrow_select::filter::filter;
195/// let array = Int32Array::from(vec![5, 6, 7, 8, 9]);
196/// let filter_array = BooleanArray::from(vec![true, false, false, true, false]);
197/// let c = filter(&array, &filter_array).unwrap();
198/// let c = c.as_any().downcast_ref::<Int32Array>().unwrap();
199/// assert_eq!(c, &Int32Array::from(vec![5, 8]));
200/// ```
201pub fn filter(values: &dyn Array, predicate: &BooleanArray) -> Result<ArrayRef, ArrowError> {
202    let mut filter_builder = FilterBuilder::new(predicate);
203
204    if FilterBuilder::is_optimize_beneficial(values.data_type()) {
205        // Only optimize if filtering more than one array
206        // Otherwise, the overhead of optimization can be more than the benefit
207        filter_builder = filter_builder.optimize();
208    }
209
210    let predicate = filter_builder.build();
211
212    filter_array(values, &predicate)
213}
214
215/// Returns a filtered [RecordBatch] where the corresponding elements of
216/// `predicate` are true.
217///
218/// This is the equivalent of calling [filter] on each column of the [RecordBatch].
219///
220/// If multiple record batches (or arrays) need to be filtered using the same predicate array,
221/// consider using [FilterBuilder] to create a single [FilterPredicate] and then
222/// calling [FilterPredicate::filter_record_batch].
223/// In contrast to this function, it is then the responsibility of the caller
224/// to use [FilterBuilder::optimize] if appropriate.
225pub fn filter_record_batch(
226    record_batch: &RecordBatch,
227    predicate: &BooleanArray,
228) -> Result<RecordBatch, ArrowError> {
229    let mut filter_builder = FilterBuilder::new(predicate);
230    let num_cols = record_batch.num_columns();
231    if num_cols > 1
232        || (num_cols > 0
233            && FilterBuilder::is_optimize_beneficial(
234                record_batch.schema_ref().field(0).data_type(),
235            ))
236    {
237        // Only optimize if filtering more than one column or if the column contains multiple internal arrays
238        // Otherwise, the overhead of optimization can be more than the benefit
239        filter_builder = filter_builder.optimize();
240    }
241    let filter = filter_builder.build();
242
243    filter.filter_record_batch(record_batch)
244}
245
246/// A builder to construct [`FilterPredicate`]
247#[derive(Debug)]
248pub struct FilterBuilder {
249    filter: BooleanArray,
250    count: usize,
251    strategy: IterationStrategy,
252}
253
254impl FilterBuilder {
255    /// Create a new [`FilterBuilder`] that can be used to construct a [`FilterPredicate`]
256    pub fn new(filter: &BooleanArray) -> Self {
257        Self::new_with_count(filter, filter.true_count())
258    }
259
260    pub(crate) fn new_with_count(filter: &BooleanArray, count: usize) -> Self {
261        let filter = match filter.null_count() {
262            0 => filter.clone(),
263            _ => prep_null_mask_filter(filter),
264        };
265
266        let strategy = IterationStrategy::default_strategy(filter.len(), count);
267
268        Self {
269            filter,
270            count,
271            strategy,
272        }
273    }
274
275    /// Compute an optimized representation of the provided `filter` mask that can be
276    /// applied to an array more quickly.
277    ///
278    /// When filtering multiple arrays (e.g. a [`RecordBatch`] or a
279    /// [`StructArray`] with multiple fields), optimizing the filter can provide
280    /// significant performance benefits.
281    ///
282    /// However, optimization takes time and can have a larger memory footprint
283    /// than the original mask, so it is often faster to filter a single array,
284    /// without filter optimization.
285    pub fn optimize(mut self) -> Self {
286        match self.strategy {
287            IterationStrategy::SlicesIterator => {
288                let slices = SlicesIterator::new(&self.filter).collect();
289                self.strategy = IterationStrategy::Slices(slices)
290            }
291            IterationStrategy::IndexIterator => {
292                let indices = IndexIterator::new(&self.filter, self.count).collect();
293                self.strategy = IterationStrategy::Indices(indices)
294            }
295            _ => {}
296        }
297        self
298    }
299
300    /// Determines if calling [FilterBuilder::optimize] is beneficial for the
301    /// given type even when filtering just a single array.
302    ///
303    /// See [`FilterBuilder::optimize`] for more details.
304    pub fn is_optimize_beneficial(data_type: &DataType) -> bool {
305        match data_type {
306            DataType::Struct(fields) => {
307                fields.len() > 1
308                    || fields.len() == 1
309                        && FilterBuilder::is_optimize_beneficial(fields[0].data_type())
310            }
311            DataType::Union(fields, UnionMode::Sparse) => !fields.is_empty(),
312            _ => false,
313        }
314    }
315
316    /// Construct the final `FilterPredicate`
317    pub fn build(self) -> FilterPredicate {
318        FilterPredicate {
319            filter: self.filter,
320            count: self.count,
321            strategy: self.strategy,
322        }
323    }
324}
325
326/// The iteration strategy used to evaluate [`FilterPredicate`]
327#[derive(Debug)]
328enum IterationStrategy {
329    /// A lazily evaluated iterator of ranges
330    SlicesIterator,
331    /// A lazily evaluated iterator of indices
332    IndexIterator,
333    /// A precomputed list of indices
334    Indices(Vec<usize>),
335    /// A precomputed array of ranges
336    Slices(Vec<(usize, usize)>),
337    /// Select all rows
338    All,
339    /// Select no rows
340    None,
341}
342
343impl IterationStrategy {
344    /// The default [`IterationStrategy`] for a filter of length `filter_length`
345    /// and selecting `filter_count` rows
346    fn default_strategy(filter_length: usize, filter_count: usize) -> Self {
347        if filter_length == 0 || filter_count == 0 {
348            return IterationStrategy::None;
349        }
350
351        if filter_count == filter_length {
352            return IterationStrategy::All;
353        }
354
355        // Compute the selectivity of the predicate by dividing the number of true
356        // bits in the predicate by the predicate's total length
357        //
358        // This can then be used as a heuristic for the optimal iteration strategy
359        let selectivity_frac = filter_count as f64 / filter_length as f64;
360        if selectivity_frac > FILTER_SLICES_SELECTIVITY_THRESHOLD {
361            return IterationStrategy::SlicesIterator;
362        }
363        IterationStrategy::IndexIterator
364    }
365}
366
367/// Borrowed description of which rows a [`FilterPredicate`] selects.
368pub(crate) enum FilterSelection<'a> {
369    None,
370    All { len: usize },
371    Slices(FilterSlices<'a>),
372    Indices(FilterIndices<'a>),
373}
374
375pub(crate) type FilterSlices<'a> =
376    FilterIterator<std::iter::Copied<std::slice::Iter<'a, (usize, usize)>>, SlicesIterator<'a>>;
377
378pub(crate) type FilterIndices<'a> =
379    FilterIterator<std::iter::Copied<std::slice::Iter<'a, usize>>, IndexIterator<'a>>;
380
381/// Holds either materialized rows or a lazy iterator.
382///
383/// This does not implement [`Iterator`] on purpose. Callers use
384/// [`Self::for_each`] or [`Self::try_for_each`] so the enum is matched once
385/// before the loop, not once per row in `next`.
386pub(crate) enum FilterIterator<M, I> {
387    Materialized(M),
388    Lazy(I),
389}
390
391impl<M, I> FilterIterator<M, I>
392where
393    M: Iterator,
394    I: Iterator<Item = M::Item>,
395{
396    pub(crate) fn for_each<F>(self, f: F)
397    where
398        F: FnMut(M::Item),
399    {
400        match self {
401            Self::Materialized(iter) => iter.for_each(f),
402            Self::Lazy(iter) => iter.for_each(f),
403        }
404    }
405
406    pub(crate) fn try_for_each<F, E>(self, mut f: F) -> Result<(), E>
407    where
408        F: FnMut(M::Item) -> Result<(), E>,
409    {
410        match self {
411            Self::Materialized(iter) => {
412                for item in iter {
413                    f(item)?;
414                }
415            }
416            Self::Lazy(iter) => {
417                for item in iter {
418                    f(item)?;
419                }
420            }
421        }
422
423        Ok(())
424    }
425}
426
427/// A filtering predicate that can be applied to an [`Array`]
428#[derive(Debug)]
429pub struct FilterPredicate {
430    filter: BooleanArray,
431    count: usize,
432    strategy: IterationStrategy,
433}
434
435impl FilterPredicate {
436    /// Selects rows from `values` based on this [`FilterPredicate`]
437    pub fn filter(&self, values: &dyn Array) -> Result<ArrayRef, ArrowError> {
438        filter_array(values, self)
439    }
440
441    /// Returns a filtered [`RecordBatch`] containing only the rows that are selected by this
442    /// [`FilterPredicate`].
443    ///
444    /// This is the equivalent of calling [filter] on each column of the [`RecordBatch`].
445    pub fn filter_record_batch(
446        &self,
447        record_batch: &RecordBatch,
448    ) -> Result<RecordBatch, ArrowError> {
449        let filtered_arrays = record_batch
450            .columns()
451            .iter()
452            .map(|a| filter_array(a, self))
453            .collect::<Result<Vec<_>, _>>()?;
454
455        // SAFETY: we know that the set of filtered arrays will match the schema of the original
456        // record batch
457        unsafe {
458            Ok(RecordBatch::new_unchecked(
459                record_batch.schema(),
460                filtered_arrays,
461                self.count,
462            ))
463        }
464    }
465
466    /// Number of rows being selected based on this [`FilterPredicate`]
467    pub fn count(&self) -> usize {
468        self.count
469    }
470
471    pub(crate) fn selection(&self) -> FilterSelection<'_> {
472        match &self.strategy {
473            IterationStrategy::None => FilterSelection::None,
474            IterationStrategy::All => FilterSelection::All { len: self.count },
475            IterationStrategy::Slices(slices) => {
476                FilterSelection::Slices(FilterIterator::Materialized(slices.iter().copied()))
477            }
478            IterationStrategy::SlicesIterator => {
479                FilterSelection::Slices(FilterIterator::Lazy(SlicesIterator::new(&self.filter)))
480            }
481            IterationStrategy::Indices(indices) => {
482                FilterSelection::Indices(FilterIterator::Materialized(indices.iter().copied()))
483            }
484            IterationStrategy::IndexIterator => FilterSelection::Indices(FilterIterator::Lazy(
485                IndexIterator::new(&self.filter, self.count),
486            )),
487        }
488    }
489
490    /// Filters the given `nulls` buffer using this predicate.
491    ///
492    /// Returns `None` when there is nothing to track in the output, either
493    /// because the input `nulls` was `None`, the input had no nulls, or the
494    /// filtered result has no nulls. Otherwise returns the filtered
495    /// [`NullBuffer`] with its precomputed null count.
496    pub fn filter_nulls(&self, nulls: Option<&NullBuffer>) -> Option<NullBuffer> {
497        let nulls = nulls?;
498        if nulls.null_count() == 0 {
499            return None;
500        }
501
502        let nulls = filter_bits(nulls.inner(), self);
503        // The filtered `nulls` has a length of `self.count` bits and therefore
504        // the null count is this minus the number of valid bits
505        let null_count = self.count - nulls.count_set_bits_offset(0, self.count);
506
507        if null_count == 0 {
508            return None;
509        }
510
511        let buffer = BooleanBuffer::new(nulls, 0, self.count);
512        debug_assert_eq!(null_count, buffer.len() - buffer.count_set_bits());
513        // SAFETY: `null_count` was derived from `buffer` above, so it matches
514        // the number of unset bits as required by `new_unchecked`.
515        Some(unsafe { NullBuffer::new_unchecked(buffer, null_count) })
516    }
517}
518
519fn filter_array(values: &dyn Array, predicate: &FilterPredicate) -> Result<ArrayRef, ArrowError> {
520    if predicate.filter.len() > values.len() {
521        return Err(ArrowError::InvalidArgumentError(format!(
522            "Filter predicate of length {} is larger than target array of length {}",
523            predicate.filter.len(),
524            values.len()
525        )));
526    }
527
528    match predicate.strategy {
529        IterationStrategy::None => Ok(new_empty_array(values.data_type())),
530        IterationStrategy::All => Ok(values.slice(0, predicate.count)),
531        // actually filter
532        _ => downcast_primitive_array! {
533            values => Ok(Arc::new(filter_primitive(values, predicate))),
534            DataType::Boolean => {
535                let values = values.as_any().downcast_ref::<BooleanArray>().unwrap();
536                Ok(Arc::new(filter_boolean(values, predicate)))
537            }
538            DataType::Utf8 => {
539                Ok(Arc::new(filter_bytes(values.as_string::<i32>(), predicate)))
540            }
541            DataType::LargeUtf8 => {
542                Ok(Arc::new(filter_bytes(values.as_string::<i64>(), predicate)))
543            }
544            DataType::Utf8View => {
545                Ok(Arc::new(filter_byte_view(values.as_string_view(), predicate)))
546            }
547            DataType::Binary => {
548                Ok(Arc::new(filter_bytes(values.as_binary::<i32>(), predicate)))
549            }
550            DataType::LargeBinary => {
551                Ok(Arc::new(filter_bytes(values.as_binary::<i64>(), predicate)))
552            }
553            DataType::BinaryView => {
554                Ok(Arc::new(filter_byte_view(values.as_binary_view(), predicate)))
555            }
556            DataType::FixedSizeBinary(_) => {
557                Ok(Arc::new(filter_fixed_size_binary(values.as_fixed_size_binary(), predicate)))
558            }
559            DataType::ListView(_) => {
560                Ok(Arc::new(filter_list_view::<i32>(values.as_list_view(), predicate)))
561            }
562            DataType::LargeListView(_) => {
563                Ok(Arc::new(filter_list_view::<i64>(values.as_list_view(), predicate)))
564            }
565            DataType::RunEndEncoded(_, _) => {
566                downcast_run_array!{
567                    values => Ok(Arc::new(filter_run_end_array(values, predicate)?)),
568                    t => unimplemented!("Filter not supported for RunEndEncoded type {:?}", t)
569                }
570            }
571            DataType::Dictionary(_, _) => downcast_dictionary_array! {
572                values => Ok(Arc::new(filter_dict(values, predicate))),
573                t => unimplemented!("Filter not supported for dictionary type {:?}", t)
574            }
575            DataType::Struct(_) => {
576                Ok(Arc::new(filter_struct(values.as_struct(), predicate)?))
577            }
578            DataType::Union(_, UnionMode::Sparse) => {
579                Ok(Arc::new(filter_sparse_union(values.as_union(), predicate)?))
580            }
581            _ => {
582                let data = values.to_data();
583                // fallback to using MutableArrayData
584                let mut mutable = MutableArrayData::new(
585                    vec![&data],
586                    false,
587                    predicate.count,
588                );
589
590                match &predicate.strategy {
591                    IterationStrategy::Slices(slices) => {
592                        for (start, end) in slices {
593                            mutable.try_extend(0, *start, *end)?;
594                        }
595                    }
596                    _ => {
597                        let iter = SlicesIterator::new(&predicate.filter);
598                        for (start, end) in iter {
599                            mutable.try_extend(0, start, end)?;
600                        }
601                    }
602                }
603
604                let data = mutable.freeze();
605                Ok(make_array(data))
606            }
607        },
608    }
609}
610
611/// Filter any supported [`RunArray`] based on a [`FilterPredicate`]
612fn filter_run_end_array<R: RunEndIndexType>(
613    array: &RunArray<R>,
614    predicate: &FilterPredicate,
615) -> Result<RunArray<R>, ArrowError>
616where
617    R::Native: Into<i64> + From<bool>,
618    R::Native: AddAssign,
619{
620    let run_ends: &RunEndBuffer<R::Native> = array.run_ends();
621    let start_physical = run_ends.get_start_physical_index();
622    let end_physical = run_ends.get_end_physical_index();
623    let physical_len = end_physical - start_physical + 1;
624
625    let mut new_run_ends = vec![R::default_value(); physical_len];
626    let offset = run_ends.offset() as u64;
627
628    let mut start = 0u64;
629    let mut j = 0;
630    let mut count = R::default_value();
631    let filter_values = predicate.filter.values();
632    let run_ends = run_ends.inner();
633
634    let pred: BooleanArray = BooleanBuffer::collect_bool(physical_len, |i| {
635        let mut keep = false;
636        let mut end = (run_ends[i + start_physical].into() as u64).saturating_sub(offset);
637        let difference = end.saturating_sub(filter_values.len() as u64);
638        end -= difference;
639
640        // Safety: we subtract the difference off `end` so we are always within bounds
641        for pred in (start..end).map(|i| unsafe { filter_values.value_unchecked(i as usize) }) {
642            count += R::Native::from(pred);
643            keep |= pred
644        }
645        // this is to avoid branching
646        new_run_ends[j] = count;
647        j += keep as usize;
648
649        start = end;
650        keep
651    })
652    .into();
653
654    new_run_ends.truncate(j);
655
656    let values = array.values_slice();
657    let values = filter(values.as_ref(), &pred)?;
658
659    let run_ends = PrimitiveArray::<R>::try_new(new_run_ends.into(), None)?;
660    RunArray::try_new(&run_ends, &values)
661}
662
663/// Computes a new null mask for `data` based on `predicate`
664///
665/// If the predicate selected no null-rows, returns `None`, otherwise returns
666/// `Some((null_count, null_buffer))` where `null_count` is the number of nulls
667/// in the filtered output, and `null_buffer` is the filtered null buffer
668///
669pub(crate) fn filter_null_mask(
670    nulls: Option<&NullBuffer>,
671    predicate: &FilterPredicate,
672) -> Option<(usize, Buffer)> {
673    let nulls = nulls?;
674    if nulls.null_count() == 0 {
675        return None;
676    }
677
678    let nulls = filter_bits(nulls.inner(), predicate);
679    // The filtered `nulls` has a length of `predicate.count` bits and
680    // therefore the null count is this minus the number of valid bits
681    let null_count = predicate.count - nulls.count_set_bits_offset(0, predicate.count);
682
683    if null_count == 0 {
684        return None;
685    }
686
687    Some((null_count, nulls))
688}
689
690/// Filter the packed bitmask `buffer`, with `predicate` starting at bit offset `offset`
691fn filter_bits(buffer: &BooleanBuffer, predicate: &FilterPredicate) -> Buffer {
692    let src = buffer.values();
693    let offset = buffer.offset();
694    assert!(buffer.len() >= predicate.filter.len());
695
696    match &predicate.strategy {
697        IterationStrategy::IndexIterator => {
698            let bits =
699                // SAFETY: IndexIterator uses the filter predicate to derive indices
700                IndexIterator::new(&predicate.filter, predicate.count).map(|src_idx| unsafe {
701                    bit_util::get_bit_raw(buffer.values().as_ptr(), src_idx + offset)
702                });
703
704            // SAFETY: `IndexIterator` reports its size correctly
705            unsafe { MutableBuffer::from_trusted_len_iter_bool(bits).into() }
706        }
707        IterationStrategy::Indices(indices) => {
708            // SAFETY: indices were derived from the filter predicate
709            let bits = indices.iter().map(|src_idx| unsafe {
710                bit_util::get_bit_raw(buffer.values().as_ptr(), *src_idx + offset)
711            });
712            // SAFETY: `Vec::iter()` reports its size correctly
713            unsafe { MutableBuffer::from_trusted_len_iter_bool(bits).into() }
714        }
715        IterationStrategy::SlicesIterator => {
716            let mut builder = BooleanBufferBuilder::new(predicate.count);
717            for (start, end) in SlicesIterator::new(&predicate.filter) {
718                builder.append_packed_range(start + offset..end + offset, src)
719            }
720            builder.into()
721        }
722        IterationStrategy::Slices(slices) => {
723            let mut builder = BooleanBufferBuilder::new(predicate.count);
724            for (start, end) in slices {
725                builder.append_packed_range(*start + offset..*end + offset, src)
726            }
727            builder.into()
728        }
729        IterationStrategy::All | IterationStrategy::None => unreachable!(),
730    }
731}
732
733/// `filter` implementation for boolean buffers
734fn filter_boolean(array: &BooleanArray, predicate: &FilterPredicate) -> BooleanArray {
735    let buffer = filter_bits(array.values(), predicate);
736    let values = BooleanBuffer::new(buffer, 0, predicate.count);
737    let nulls = predicate.filter_nulls(array.nulls());
738
739    BooleanArray::new(values, nulls)
740}
741
742#[inline(never)]
743pub(crate) fn filter_native<T: ArrowNativeType>(
744    values: &[T],
745    predicate: &FilterPredicate,
746) -> Buffer {
747    assert!(values.len() >= predicate.filter.len());
748
749    match &predicate.strategy {
750        IterationStrategy::SlicesIterator => {
751            let mut buffer = Vec::with_capacity(predicate.count);
752            for (start, end) in SlicesIterator::new(&predicate.filter) {
753                // SAFETY: indices were derived from the filter predicate
754                buffer.extend_from_slice(unsafe { values.get_unchecked(start..end) });
755            }
756            buffer.into()
757        }
758        IterationStrategy::Slices(slices) => {
759            let mut buffer = Vec::with_capacity(predicate.count);
760            for (start, end) in slices {
761                // SAFETY: indices were derived from the filter predicate
762                buffer.extend_from_slice(unsafe { values.get_unchecked(*start..*end) });
763            }
764            buffer.into()
765        }
766        IterationStrategy::IndexIterator => {
767            // SAFETY: indices were derived from the filter predicate
768            let iter = IndexIterator::new(&predicate.filter, predicate.count)
769                .map(|x| unsafe { *values.get_unchecked(x) });
770
771            // SAFETY: IndexIterator is trusted length
772            unsafe { MutableBuffer::from_trusted_len_iter(iter) }.into()
773        }
774        IterationStrategy::Indices(indices) => {
775            // SAFETY: indices were derived from the filter predicate
776            let iter = indices.iter().map(|x| unsafe { *values.get_unchecked(*x) });
777            iter.collect::<Vec<_>>().into()
778        }
779        IterationStrategy::All | IterationStrategy::None => unreachable!(),
780    }
781}
782
783/// `filter` implementation for primitive arrays
784fn filter_primitive<T>(array: &PrimitiveArray<T>, predicate: &FilterPredicate) -> PrimitiveArray<T>
785where
786    T: ArrowPrimitiveType,
787{
788    let buffer = filter_native(array.values(), predicate);
789    let values = ScalarBuffer::new(buffer, 0, predicate.count);
790    let nulls = predicate.filter_nulls(array.nulls());
791    let filtered = PrimitiveArray::new(values, nulls);
792
793    // Avoid the compatibility check when the physical type already matches.
794    if array.data_type() == &T::DATA_TYPE {
795        filtered
796    } else {
797        filtered.with_data_type(array.data_type().clone())
798    }
799}
800
801/// [`FilterBytes`] is created from a source [`GenericByteArray`] and can be
802/// used to build a new [`GenericByteArray`] by copying values from the source
803///
804/// TODO(raphael): Could this be used for the take kernel as well?
805struct FilterBytes<'a, OffsetSize> {
806    src_offsets: &'a [OffsetSize],
807    src_values: &'a [u8],
808    dst_offsets: Vec<OffsetSize>,
809    dst_values: Vec<u8>,
810    cur_offset: OffsetSize,
811}
812
813impl<'a, OffsetSize> FilterBytes<'a, OffsetSize>
814where
815    OffsetSize: OffsetSizeTrait,
816{
817    fn new<T>(capacity: usize, array: &'a GenericByteArray<T>) -> Self
818    where
819        T: ByteArrayType<Offset = OffsetSize>,
820    {
821        let dst_values = Vec::new();
822        let mut dst_offsets: Vec<OffsetSize> = Vec::with_capacity(capacity + 1);
823        let cur_offset = OffsetSize::from_usize(0).unwrap();
824
825        dst_offsets.push(cur_offset);
826
827        Self {
828            src_offsets: array.value_offsets(),
829            src_values: array.value_data(),
830            dst_offsets,
831            dst_values,
832            cur_offset,
833        }
834    }
835
836    /// Returns the byte offset at `idx`
837    #[inline]
838    fn get_value_offset(&self, idx: usize) -> usize {
839        self.src_offsets[idx].as_usize()
840    }
841
842    /// Returns the start and end of the value at index `idx` along with its length
843    #[inline]
844    fn get_value_range(&self, idx: usize) -> (usize, usize, OffsetSize) {
845        // These can only fail if `array` contains invalid data
846        let start = self.get_value_offset(idx);
847        let end = self.get_value_offset(idx + 1);
848        let len = OffsetSize::from_usize(end - start).expect("illegal offset range");
849        (start, end, len)
850    }
851
852    fn extend_offsets_idx(&mut self, iter: impl Iterator<Item = usize>) {
853        self.dst_offsets.extend(iter.map(|idx| {
854            let start = self.src_offsets[idx].as_usize();
855            let end = self.src_offsets[idx + 1].as_usize();
856            let len = OffsetSize::from_usize(end - start).expect("illegal offset range");
857            self.cur_offset += len;
858
859            self.cur_offset
860        }));
861    }
862
863    /// Extends the in-progress array by the indexes in the provided iterator
864    fn extend_idx(&mut self, iter: impl Iterator<Item = usize>) {
865        self.dst_values.reserve_exact(self.cur_offset.as_usize());
866
867        for idx in iter {
868            let start = self.src_offsets[idx].as_usize();
869            let end = self.src_offsets[idx + 1].as_usize();
870            self.dst_values
871                .extend_from_slice(&self.src_values[start..end]);
872        }
873    }
874
875    fn extend_offsets_slices(&mut self, iter: impl Iterator<Item = (usize, usize)>, count: usize) {
876        self.dst_offsets.reserve_exact(count);
877        for (start, end) in iter {
878            // These can only fail if `array` contains invalid data
879            for idx in start..end {
880                let (_, _, len) = self.get_value_range(idx);
881                self.cur_offset += len;
882                self.dst_offsets.push(self.cur_offset);
883            }
884        }
885    }
886
887    /// Extends the in-progress array by the ranges in the provided iterator
888    fn extend_slices(&mut self, iter: impl Iterator<Item = (usize, usize)>) {
889        self.dst_values.reserve_exact(self.cur_offset.as_usize());
890
891        for (start, end) in iter {
892            let value_start = self.get_value_offset(start);
893            let value_end = self.get_value_offset(end);
894            self.dst_values
895                .extend_from_slice(&self.src_values[value_start..value_end]);
896        }
897    }
898}
899
900/// `filter` implementation for byte arrays
901///
902/// Note: NULLs with a non-zero slot length in `array` will have the corresponding
903/// data copied across. This allows handling the null mask separately from the data
904fn filter_bytes<T>(array: &GenericByteArray<T>, predicate: &FilterPredicate) -> GenericByteArray<T>
905where
906    T: ByteArrayType,
907{
908    let mut filter = FilterBytes::new(predicate.count, array);
909
910    match &predicate.strategy {
911        IterationStrategy::SlicesIterator => {
912            filter.extend_offsets_slices(SlicesIterator::new(&predicate.filter), predicate.count);
913            filter.extend_slices(SlicesIterator::new(&predicate.filter))
914        }
915        IterationStrategy::Slices(slices) => {
916            filter.extend_offsets_slices(slices.iter().cloned(), predicate.count);
917            filter.extend_slices(slices.iter().cloned())
918        }
919        IterationStrategy::IndexIterator => {
920            filter.extend_offsets_idx(IndexIterator::new(&predicate.filter, predicate.count));
921            filter.extend_idx(IndexIterator::new(&predicate.filter, predicate.count))
922        }
923        IterationStrategy::Indices(indices) => {
924            filter.extend_offsets_idx(indices.iter().cloned());
925            filter.extend_idx(indices.iter().cloned())
926        }
927        IterationStrategy::All | IterationStrategy::None => unreachable!(),
928    }
929
930    // SAFETY: `dst_offsets` starts at `[0]` and only grows by the running
931    // `cur_offset`, so it is monotonically non-decreasing.
932    let offsets = unsafe { OffsetBuffer::new_unchecked(filter.dst_offsets.into()) };
933    let nulls = predicate.filter_nulls(array.nulls());
934
935    // SAFETY: `offsets` index into `dst_values` by construction, and each slot
936    // is a byte-for-byte copy from `array`, so UTF-8 validity (if any) is preserved.
937    // Length invariant: `offsets.len() - 1 == predicate.count == nulls.len()`.
938    unsafe { GenericByteArray::new_unchecked(offsets, filter.dst_values.into(), nulls) }
939}
940
941/// `filter` implementation for byte view arrays.
942fn filter_byte_view<T: ByteViewType>(
943    array: &GenericByteViewArray<T>,
944    predicate: &FilterPredicate,
945) -> GenericByteViewArray<T> {
946    let new_view_buffer = filter_native(array.views(), predicate);
947    let views = ScalarBuffer::new(new_view_buffer, 0, predicate.count);
948    let buffers = array.data_buffers().to_vec();
949    let nulls = predicate.filter_nulls(array.nulls());
950
951    // SAFETY: each view is copied unchanged from `array.views()` and `buffers`
952    // is the same buffer list, so every view still points to an in-bounds
953    // (and, for strings, UTF-8 valid) range.
954    unsafe { GenericByteViewArray::new_unchecked(views, buffers, nulls) }
955}
956
957fn filter_fixed_size_binary(
958    array: &FixedSizeBinaryArray,
959    predicate: &FilterPredicate,
960) -> FixedSizeBinaryArray {
961    let values: &[u8] = array.values();
962    let value_length = array.value_length() as usize;
963    let calculate_offset_from_index = |index: usize| index * value_length;
964    let buffer = match &predicate.strategy {
965        IterationStrategy::SlicesIterator => {
966            let mut buffer = MutableBuffer::with_capacity(predicate.count * value_length);
967            for (start, end) in SlicesIterator::new(&predicate.filter) {
968                buffer.extend_from_slice(
969                    &values[calculate_offset_from_index(start)..calculate_offset_from_index(end)],
970                );
971            }
972            buffer
973        }
974        IterationStrategy::Slices(slices) => {
975            let mut buffer = MutableBuffer::with_capacity(predicate.count * value_length);
976            for (start, end) in slices {
977                buffer.extend_from_slice(
978                    &values[calculate_offset_from_index(*start)..calculate_offset_from_index(*end)],
979                );
980            }
981            buffer
982        }
983        IterationStrategy::IndexIterator => {
984            let iter = IndexIterator::new(&predicate.filter, predicate.count).map(|x| {
985                &values[calculate_offset_from_index(x)..calculate_offset_from_index(x + 1)]
986            });
987
988            let mut buffer = MutableBuffer::new(predicate.count * value_length);
989            iter.for_each(|item| buffer.extend_from_slice(item));
990            buffer
991        }
992        IterationStrategy::Indices(indices) => {
993            let iter = indices.iter().map(|x| {
994                &values[calculate_offset_from_index(*x)..calculate_offset_from_index(*x + 1)]
995            });
996
997            let mut buffer = MutableBuffer::new(predicate.count * value_length);
998            iter.for_each(|item| buffer.extend_from_slice(item));
999            buffer
1000        }
1001        IterationStrategy::All | IterationStrategy::None => unreachable!(),
1002    };
1003
1004    let nulls = predicate.filter_nulls(array.nulls());
1005
1006    FixedSizeBinaryArray::new(array.value_length(), buffer.into(), nulls)
1007}
1008
1009/// `filter` implementation for dictionaries
1010fn filter_dict<K: ArrowDictionaryKeyType>(
1011    array: &DictionaryArray<K>,
1012    predicate: &FilterPredicate,
1013) -> DictionaryArray<K> {
1014    // SAFETY:
1015    // Keys were valid before, filtered subset is therefore still valid
1016    let new_keys = filter_primitive(array.keys(), predicate);
1017    unsafe { DictionaryArray::new_unchecked(new_keys, array.values().clone()) }
1018}
1019
1020/// `filter` implementation for structs
1021fn filter_struct(
1022    array: &StructArray,
1023    predicate: &FilterPredicate,
1024) -> Result<StructArray, ArrowError> {
1025    let columns = array
1026        .columns()
1027        .iter()
1028        .map(|column| filter_array(column, predicate))
1029        .collect::<Result<_, _>>()?;
1030
1031    let nulls = predicate.filter_nulls(array.nulls());
1032
1033    Ok(unsafe {
1034        StructArray::new_unchecked_with_length(
1035            array.fields().clone(),
1036            columns,
1037            nulls,
1038            predicate.count(),
1039        )
1040    })
1041}
1042
1043/// `filter` implementation for sparse unions
1044fn filter_sparse_union(
1045    array: &UnionArray,
1046    predicate: &FilterPredicate,
1047) -> Result<UnionArray, ArrowError> {
1048    let DataType::Union(fields, UnionMode::Sparse) = array.data_type() else {
1049        unreachable!()
1050    };
1051
1052    let type_ids = filter_primitive(
1053        &Int8Array::try_new(array.type_ids().clone(), None)?,
1054        predicate,
1055    );
1056
1057    let children = fields
1058        .iter()
1059        .map(|(child_type_id, _)| filter_array(array.child(child_type_id), predicate))
1060        .collect::<Result<_, _>>()?;
1061
1062    Ok(unsafe {
1063        UnionArray::new_unchecked(fields.clone(), type_ids.into_parts().1, None, children)
1064    })
1065}
1066
1067/// `filter` implementation for list views
1068fn filter_list_view<OffsetType: OffsetSizeTrait>(
1069    array: &GenericListViewArray<OffsetType>,
1070    predicate: &FilterPredicate,
1071) -> GenericListViewArray<OffsetType> {
1072    let filtered_offsets = filter_native::<OffsetType>(array.offsets(), predicate);
1073    let filtered_sizes = filter_native::<OffsetType>(array.sizes(), predicate);
1074
1075    let field = match array.data_type() {
1076        DataType::ListView(field) | DataType::LargeListView(field) => field.clone(),
1077        _ => unreachable!(),
1078    };
1079    let offsets = ScalarBuffer::new(filtered_offsets, 0, predicate.count);
1080    let sizes = ScalarBuffer::new(filtered_sizes, 0, predicate.count);
1081    let values = array.values().clone();
1082    let nulls = predicate.filter_nulls(array.nulls());
1083
1084    // SAFETY: each `(offset, size)` pair is copied unchanged from `array` and
1085    // indexes into the same `values` child, so every range stays in-bounds.
1086    // `field` and `values`' data type are unchanged from `array`.
1087    unsafe { GenericListViewArray::new_unchecked(field, offsets, sizes, values, nulls) }
1088}
1089
1090#[cfg(test)]
1091mod tests {
1092    use super::*;
1093    use arrow_array::builder::*;
1094    use arrow_array::cast::as_run_array;
1095    use arrow_array::types::*;
1096    use rand::distr::uniform::{UniformSampler, UniformUsize};
1097    use rand::distr::{Alphanumeric, StandardUniform};
1098    use rand::prelude::*;
1099    use rand::rng;
1100
1101    macro_rules! def_temporal_test {
1102        ($test:ident, $array_type: ident, $data: expr) => {
1103            #[test]
1104            fn $test() {
1105                let a = $data;
1106                let b = BooleanArray::from(vec![true, false, true, false]);
1107                let c = filter(&a, &b).unwrap();
1108                let d = c.as_ref().as_any().downcast_ref::<$array_type>().unwrap();
1109                assert_eq!(2, d.len());
1110                assert_eq!(1, d.value(0));
1111                assert_eq!(3, d.value(1));
1112            }
1113        };
1114    }
1115
1116    def_temporal_test!(
1117        test_filter_date32,
1118        Date32Array,
1119        Date32Array::from(vec![1, 2, 3, 4])
1120    );
1121    def_temporal_test!(
1122        test_filter_date64,
1123        Date64Array,
1124        Date64Array::from(vec![1, 2, 3, 4])
1125    );
1126    def_temporal_test!(
1127        test_filter_time32_second,
1128        Time32SecondArray,
1129        Time32SecondArray::from(vec![1, 2, 3, 4])
1130    );
1131    def_temporal_test!(
1132        test_filter_time32_millisecond,
1133        Time32MillisecondArray,
1134        Time32MillisecondArray::from(vec![1, 2, 3, 4])
1135    );
1136    def_temporal_test!(
1137        test_filter_time64_microsecond,
1138        Time64MicrosecondArray,
1139        Time64MicrosecondArray::from(vec![1, 2, 3, 4])
1140    );
1141    def_temporal_test!(
1142        test_filter_time64_nanosecond,
1143        Time64NanosecondArray,
1144        Time64NanosecondArray::from(vec![1, 2, 3, 4])
1145    );
1146    def_temporal_test!(
1147        test_filter_duration_second,
1148        DurationSecondArray,
1149        DurationSecondArray::from(vec![1, 2, 3, 4])
1150    );
1151    def_temporal_test!(
1152        test_filter_duration_millisecond,
1153        DurationMillisecondArray,
1154        DurationMillisecondArray::from(vec![1, 2, 3, 4])
1155    );
1156    def_temporal_test!(
1157        test_filter_duration_microsecond,
1158        DurationMicrosecondArray,
1159        DurationMicrosecondArray::from(vec![1, 2, 3, 4])
1160    );
1161    def_temporal_test!(
1162        test_filter_duration_nanosecond,
1163        DurationNanosecondArray,
1164        DurationNanosecondArray::from(vec![1, 2, 3, 4])
1165    );
1166    def_temporal_test!(
1167        test_filter_timestamp_second,
1168        TimestampSecondArray,
1169        TimestampSecondArray::from(vec![1, 2, 3, 4])
1170    );
1171    def_temporal_test!(
1172        test_filter_timestamp_millisecond,
1173        TimestampMillisecondArray,
1174        TimestampMillisecondArray::from(vec![1, 2, 3, 4])
1175    );
1176    def_temporal_test!(
1177        test_filter_timestamp_microsecond,
1178        TimestampMicrosecondArray,
1179        TimestampMicrosecondArray::from(vec![1, 2, 3, 4])
1180    );
1181    def_temporal_test!(
1182        test_filter_timestamp_nanosecond,
1183        TimestampNanosecondArray,
1184        TimestampNanosecondArray::from(vec![1, 2, 3, 4])
1185    );
1186
1187    #[test]
1188    fn test_filter_array_slice() {
1189        let a = Int32Array::from(vec![5, 6, 7, 8, 9]).slice(1, 4);
1190        let b = BooleanArray::from(vec![true, false, false, true]);
1191        // filtering with sliced filter array is not currently supported
1192        // let b_slice = BooleanArray::from(vec![true, false, false, true, false]).slice(1, 4);
1193        // let b = b_slice.as_any().downcast_ref().unwrap();
1194        let c = filter(&a, &b).unwrap();
1195        let d = c.as_ref().as_any().downcast_ref::<Int32Array>().unwrap();
1196        assert_eq!(2, d.len());
1197        assert_eq!(6, d.value(0));
1198        assert_eq!(9, d.value(1));
1199    }
1200
1201    #[test]
1202    fn test_filter_array_low_density() {
1203        // this test exercises the all 0's branch of the filter algorithm
1204        let mut data_values = (1..=65).collect::<Vec<i32>>();
1205        let mut filter_values = (1..=65).map(|i| matches!(i % 65, 0)).collect::<Vec<bool>>();
1206        // set up two more values after the batch
1207        data_values.extend_from_slice(&[66, 67]);
1208        filter_values.extend_from_slice(&[false, true]);
1209        let a = Int32Array::from(data_values);
1210        let b = BooleanArray::from(filter_values);
1211        let c = filter(&a, &b).unwrap();
1212        let d = c.as_ref().as_any().downcast_ref::<Int32Array>().unwrap();
1213        assert_eq!(2, d.len());
1214        assert_eq!(65, d.value(0));
1215        assert_eq!(67, d.value(1));
1216    }
1217
1218    #[test]
1219    fn test_filter_array_high_density() {
1220        // this test exercises the all 1's branch of the filter algorithm
1221        let mut data_values = (1..=65).map(Some).collect::<Vec<_>>();
1222        let mut filter_values = (1..=65)
1223            .map(|i| !matches!(i % 65, 0))
1224            .collect::<Vec<bool>>();
1225        // set second data value to null
1226        data_values[1] = None;
1227        // set up two more values after the batch
1228        data_values.extend_from_slice(&[Some(66), None, Some(67), None]);
1229        filter_values.extend_from_slice(&[false, true, true, true]);
1230        let a = Int32Array::from(data_values);
1231        let b = BooleanArray::from(filter_values);
1232        let c = filter(&a, &b).unwrap();
1233        let d = c.as_ref().as_any().downcast_ref::<Int32Array>().unwrap();
1234        assert_eq!(67, d.len());
1235        assert_eq!(3, d.null_count());
1236        assert_eq!(1, d.value(0));
1237        assert!(d.is_null(1));
1238        assert_eq!(64, d.value(63));
1239        assert!(d.is_null(64));
1240        assert_eq!(67, d.value(65));
1241    }
1242
1243    #[test]
1244    fn test_filter_string_array_simple() {
1245        let a = StringArray::from(vec!["hello", " ", "world", "!"]);
1246        let b = BooleanArray::from(vec![true, false, true, false]);
1247        let c = filter(&a, &b).unwrap();
1248        let d = c.as_ref().as_any().downcast_ref::<StringArray>().unwrap();
1249        assert_eq!(2, d.len());
1250        assert_eq!("hello", d.value(0));
1251        assert_eq!("world", d.value(1));
1252    }
1253
1254    #[test]
1255    fn test_filter_primitive_array_with_null() {
1256        let a = Int32Array::from(vec![Some(5), None]);
1257        let b = BooleanArray::from(vec![false, true]);
1258        let c = filter(&a, &b).unwrap();
1259        let d = c.as_ref().as_any().downcast_ref::<Int32Array>().unwrap();
1260        assert_eq!(1, d.len());
1261        assert!(d.is_null(0));
1262    }
1263
1264    #[test]
1265    fn test_filter_string_array_with_null() {
1266        let a = StringArray::from(vec![Some("hello"), None, Some("world"), None]);
1267        let b = BooleanArray::from(vec![true, false, false, true]);
1268        let c = filter(&a, &b).unwrap();
1269        let d = c.as_ref().as_any().downcast_ref::<StringArray>().unwrap();
1270        assert_eq!(2, d.len());
1271        assert_eq!("hello", d.value(0));
1272        assert!(!d.is_null(0));
1273        assert!(d.is_null(1));
1274    }
1275
1276    #[test]
1277    fn test_filter_binary_array_with_null() {
1278        let data: Vec<Option<&[u8]>> = vec![Some(b"hello"), None, Some(b"world"), None];
1279        let a = BinaryArray::from(data);
1280        let b = BooleanArray::from(vec![true, false, false, true]);
1281        let c = filter(&a, &b).unwrap();
1282        let d = c.as_ref().as_any().downcast_ref::<BinaryArray>().unwrap();
1283        assert_eq!(2, d.len());
1284        assert_eq!(b"hello", d.value(0));
1285        assert!(!d.is_null(0));
1286        assert!(d.is_null(1));
1287    }
1288
1289    fn _test_filter_byte_view<T>()
1290    where
1291        T: ByteViewType,
1292        str: AsRef<T::Native>,
1293        T::Native: PartialEq,
1294    {
1295        let array = {
1296            // ["hello", "world", null, "large payload over 12 bytes", "lulu"]
1297            let mut builder = GenericByteViewBuilder::<T>::new();
1298            builder.append_value("hello");
1299            builder.append_value("world");
1300            builder.append_null();
1301            builder.append_value("large payload over 12 bytes");
1302            builder.append_value("lulu");
1303            builder.finish()
1304        };
1305
1306        {
1307            let predicate = BooleanArray::from(vec![true, false, true, true, false]);
1308            let actual = filter(&array, &predicate).unwrap();
1309
1310            assert_eq!(actual.len(), 3);
1311
1312            let expected = {
1313                // ["hello", null, "large payload over 12 bytes"]
1314                let mut builder = GenericByteViewBuilder::<T>::new();
1315                builder.append_value("hello");
1316                builder.append_null();
1317                builder.append_value("large payload over 12 bytes");
1318                builder.finish()
1319            };
1320
1321            assert_eq!(actual.as_ref(), &expected);
1322        }
1323
1324        {
1325            let predicate = BooleanArray::from(vec![true, false, false, false, true]);
1326            let actual = filter(&array, &predicate).unwrap();
1327
1328            assert_eq!(actual.len(), 2);
1329
1330            let expected = {
1331                // ["hello", "lulu"]
1332                let mut builder = GenericByteViewBuilder::<T>::new();
1333                builder.append_value("hello");
1334                builder.append_value("lulu");
1335                builder.finish()
1336            };
1337
1338            assert_eq!(actual.as_ref(), &expected);
1339        }
1340    }
1341
1342    #[test]
1343    fn test_filter_string_view() {
1344        _test_filter_byte_view::<StringViewType>()
1345    }
1346
1347    #[test]
1348    fn test_filter_binary_view() {
1349        _test_filter_byte_view::<BinaryViewType>()
1350    }
1351
1352    #[test]
1353    fn test_filter_fixed_binary() {
1354        let v1 = [1_u8, 2];
1355        let v2 = [3_u8, 4];
1356        let v3 = [5_u8, 6];
1357        let v = vec![&v1, &v2, &v3];
1358        let a = FixedSizeBinaryArray::try_from(v).unwrap();
1359        let b = BooleanArray::from(vec![true, false, true]);
1360        let c = filter(&a, &b).unwrap();
1361        let d = c
1362            .as_ref()
1363            .as_any()
1364            .downcast_ref::<FixedSizeBinaryArray>()
1365            .unwrap();
1366        assert_eq!(d.len(), 2);
1367        assert_eq!(d.value(0), &v1);
1368        assert_eq!(d.value(1), &v3);
1369        let c2 = FilterBuilder::new(&b)
1370            .optimize()
1371            .build()
1372            .filter(&a)
1373            .unwrap();
1374        let d2 = c2
1375            .as_ref()
1376            .as_any()
1377            .downcast_ref::<FixedSizeBinaryArray>()
1378            .unwrap();
1379        assert_eq!(d, d2);
1380
1381        let b = BooleanArray::from(vec![false, false, false]);
1382        let c = filter(&a, &b).unwrap();
1383        let d = c
1384            .as_ref()
1385            .as_any()
1386            .downcast_ref::<FixedSizeBinaryArray>()
1387            .unwrap();
1388        assert_eq!(d.len(), 0);
1389
1390        let b = BooleanArray::from(vec![true, true, true]);
1391        let c = filter(&a, &b).unwrap();
1392        let d = c
1393            .as_ref()
1394            .as_any()
1395            .downcast_ref::<FixedSizeBinaryArray>()
1396            .unwrap();
1397        assert_eq!(d.len(), 3);
1398        assert_eq!(d.value(0), &v1);
1399        assert_eq!(d.value(1), &v2);
1400        assert_eq!(d.value(2), &v3);
1401
1402        let b = BooleanArray::from(vec![false, false, true]);
1403        let c = filter(&a, &b).unwrap();
1404        let d = c
1405            .as_ref()
1406            .as_any()
1407            .downcast_ref::<FixedSizeBinaryArray>()
1408            .unwrap();
1409        assert_eq!(d.len(), 1);
1410        assert_eq!(d.value(0), &v3);
1411        let c2 = FilterBuilder::new(&b)
1412            .optimize()
1413            .build()
1414            .filter(&a)
1415            .unwrap();
1416        let d2 = c2
1417            .as_ref()
1418            .as_any()
1419            .downcast_ref::<FixedSizeBinaryArray>()
1420            .unwrap();
1421        assert_eq!(d, d2);
1422    }
1423
1424    #[test]
1425    fn test_filter_array_slice_with_null() {
1426        let a = Int32Array::from(vec![Some(5), None, Some(7), Some(8), Some(9)]).slice(1, 4);
1427        let b = BooleanArray::from(vec![true, false, false, true]);
1428        // filtering with sliced filter array is not currently supported
1429        // let b_slice = BooleanArray::from(vec![true, false, false, true, false]).slice(1, 4);
1430        // let b = b_slice.as_any().downcast_ref().unwrap();
1431        let c = filter(&a, &b).unwrap();
1432        let d = c.as_ref().as_any().downcast_ref::<Int32Array>().unwrap();
1433        assert_eq!(2, d.len());
1434        assert!(d.is_null(0));
1435        assert!(!d.is_null(1));
1436        assert_eq!(9, d.value(1));
1437    }
1438
1439    #[test]
1440    fn test_filter_run_end_encoding_array() {
1441        let run_ends = Int64Array::from(vec![2, 3, 8]);
1442        let values = Int64Array::from(vec![7, -2, 9]);
1443        let a = RunArray::try_new(&run_ends, &values).expect("Failed to create RunArray");
1444        let b = BooleanArray::from(vec![true, false, true, false, true, false, true, false]);
1445        let c = filter(&a, &b).unwrap();
1446        let actual: &RunArray<Int64Type> = as_run_array(&c);
1447        assert_eq!(4, actual.len());
1448
1449        let expected = RunArray::try_new(
1450            &Int64Array::from(vec![1, 2, 4]),
1451            &Int64Array::from(vec![7, -2, 9]),
1452        )
1453        .expect("Failed to make expected RunArray test is broken");
1454
1455        assert_eq!(&actual.run_ends().values(), &expected.run_ends().values());
1456        assert_eq!(actual.values(), expected.values())
1457    }
1458
1459    #[test]
1460    fn test_filter_run_end_encoding_array_sliced() {
1461        let run_ends = Int64Array::from(vec![2, 3, 8]);
1462        let values = Int64Array::from(vec![7, -2, 9]);
1463        let a = RunArray::try_new(&run_ends, &values).unwrap(); // [7, 7, -2, 9, 9, 9, 9, 9]
1464        let a = a.slice(2, 3); // [-2, 9, 9]
1465        let b = BooleanArray::from(vec![true, false, true]);
1466        let result = filter(&a, &b).unwrap();
1467
1468        let result = result.as_run::<Int64Type>();
1469        let result = result.downcast::<Int64Array>().unwrap();
1470
1471        let expected = vec![-2, 9];
1472        let actual = result.into_iter().flatten().collect::<Vec<_>>();
1473        assert_eq!(expected, actual);
1474    }
1475
1476    #[test]
1477    fn test_filter_run_end_encoding_array_remove_value() {
1478        let run_ends = Int32Array::from(vec![2, 3, 8, 10]);
1479        let values = Int32Array::from(vec![7, -2, 9, -8]);
1480        let a = RunArray::try_new(&run_ends, &values).expect("Failed to create RunArray");
1481        let b = BooleanArray::from(vec![
1482            false, true, false, false, true, false, true, false, false, false,
1483        ]);
1484        let c = filter(&a, &b).unwrap();
1485        let actual: &RunArray<Int32Type> = as_run_array(&c);
1486        assert_eq!(3, actual.len());
1487
1488        let expected =
1489            RunArray::try_new(&Int32Array::from(vec![1, 3]), &Int32Array::from(vec![7, 9]))
1490                .expect("Failed to make expected RunArray test is broken");
1491
1492        assert_eq!(&actual.run_ends().values(), &expected.run_ends().values());
1493        assert_eq!(actual.values(), expected.values())
1494    }
1495
1496    #[test]
1497    fn test_filter_run_end_encoding_array_remove_all_but_one() {
1498        let run_ends = Int16Array::from(vec![2, 3, 8, 10]);
1499        let values = Int16Array::from(vec![7, -2, 9, -8]);
1500        let a = RunArray::try_new(&run_ends, &values).expect("Failed to create RunArray");
1501        let b = BooleanArray::from(vec![
1502            false, false, false, false, false, false, true, false, false, false,
1503        ]);
1504        let c = filter(&a, &b).unwrap();
1505        let actual: &RunArray<Int16Type> = as_run_array(&c);
1506        assert_eq!(1, actual.len());
1507
1508        let expected = RunArray::try_new(&Int16Array::from(vec![1]), &Int16Array::from(vec![9]))
1509            .expect("Failed to make expected RunArray test is broken");
1510
1511        assert_eq!(&actual.run_ends().values(), &expected.run_ends().values());
1512        assert_eq!(actual.values(), expected.values())
1513    }
1514
1515    #[test]
1516    fn test_filter_run_end_encoding_array_empty() {
1517        let run_ends = Int64Array::from(vec![2, 3, 8, 10]);
1518        let values = Int64Array::from(vec![7, -2, 9, -8]);
1519        let a = RunArray::try_new(&run_ends, &values).expect("Failed to create RunArray");
1520        let b = BooleanArray::from(vec![
1521            false, false, false, false, false, false, false, false, false, false,
1522        ]);
1523        let c = filter(&a, &b).unwrap();
1524        let actual: &RunArray<Int64Type> = as_run_array(&c);
1525        assert_eq!(0, actual.len());
1526    }
1527
1528    #[test]
1529    fn test_filter_run_end_encoding_array_max_value_gt_predicate_len() {
1530        let run_ends = Int64Array::from(vec![2, 3, 8, 10]);
1531        let values = Int64Array::from(vec![7, -2, 9, -8]);
1532        let a = RunArray::try_new(&run_ends, &values).expect("Failed to create RunArray");
1533        let b = BooleanArray::from(vec![false, true, true]);
1534        let c = filter(&a, &b).unwrap();
1535        let actual: &RunArray<Int64Type> = as_run_array(&c);
1536        assert_eq!(2, actual.len());
1537
1538        let expected = RunArray::try_new(
1539            &Int64Array::from(vec![1, 2]),
1540            &Int64Array::from(vec![7, -2]),
1541        )
1542        .expect("Failed to make expected RunArray test is broken");
1543
1544        assert_eq!(&actual.run_ends().values(), &expected.run_ends().values());
1545        assert_eq!(actual.values(), expected.values())
1546    }
1547
1548    #[test]
1549    fn test_filter_dictionary_array() {
1550        let values = [Some("hello"), None, Some("world"), Some("!")];
1551        let a: Int8DictionaryArray = values.iter().copied().collect();
1552        let b = BooleanArray::from(vec![false, true, true, false]);
1553        let c = filter(&a, &b).unwrap();
1554        let d = c
1555            .as_ref()
1556            .as_any()
1557            .downcast_ref::<Int8DictionaryArray>()
1558            .unwrap();
1559        let value_array = d.values();
1560        let values = value_array.as_any().downcast_ref::<StringArray>().unwrap();
1561        // values are cloned in the filtered dictionary array
1562        assert_eq!(3, values.len());
1563        // but keys are filtered
1564        assert_eq!(2, d.len());
1565        assert!(d.is_null(0));
1566        assert_eq!("world", values.value(d.keys().value(1) as usize));
1567    }
1568
1569    #[test]
1570    fn test_filter_list_array() {
1571        let field = Arc::new(Field::new_list_field(DataType::Int32, false));
1572        let offsets = OffsetBuffer::new(vec![0i64, 3, 6, 8, 8].into());
1573        let value_array = Arc::new(Int32Array::from_iter_values(0..8));
1574        let nulls = Some(NullBuffer::from(vec![true, true, true, false]));
1575        //  a = [[0, 1, 2], [3, 4, 5], [6, 7], null]
1576        let a = LargeListArray::new(field.clone(), offsets, value_array, nulls);
1577        let b = BooleanArray::from(vec![false, true, false, true]);
1578        let result = filter(&a, &b).unwrap();
1579
1580        // expected: [[3, 4, 5], null]
1581        let offsets = OffsetBuffer::new(vec![0i64, 3, 3].into());
1582        let value_array = Arc::new(Int32Array::from_iter_values([3, 4, 5]));
1583        let nulls = Some(NullBuffer::from(vec![true, false]));
1584        let expected: ArrayRef = Arc::new(LargeListArray::new(field, offsets, value_array, nulls));
1585
1586        assert_eq!(&expected, &result);
1587    }
1588
1589    fn test_case_filter_list_view<T: OffsetSizeTrait>() {
1590        // [[1, 2], null, [], [3,4]]
1591        let mut list_array = GenericListViewBuilder::<T, _>::new(Int32Builder::new());
1592        list_array.append_value([Some(1), Some(2)]);
1593        list_array.append_null();
1594        list_array.append_value([]);
1595        list_array.append_value([Some(3), Some(4)]);
1596
1597        let list_array = list_array.finish();
1598        let predicate = BooleanArray::from_iter([true, false, true, false]);
1599
1600        // Filter result: [[1, 2], []]
1601        let filtered = filter(&list_array, &predicate)
1602            .unwrap()
1603            .as_list_view::<T>()
1604            .clone();
1605
1606        let mut expected =
1607            GenericListViewBuilder::<T, _>::with_capacity(Int32Builder::with_capacity(5), 3);
1608        expected.append_value([Some(1), Some(2)]);
1609        expected.append_value([]);
1610        let expected = expected.finish();
1611
1612        assert_eq!(&filtered, &expected);
1613    }
1614
1615    fn test_case_filter_sliced_list_view<T: OffsetSizeTrait>() {
1616        // [[1, 2], null, [], [3,4]]
1617        let mut list_array =
1618            GenericListViewBuilder::<T, _>::with_capacity(Int32Builder::with_capacity(6), 4);
1619        list_array.append_value([Some(1), Some(2)]);
1620        list_array.append_null();
1621        list_array.append_value([]);
1622        list_array.append_value([Some(3), Some(4)]);
1623
1624        let list_array = list_array.finish();
1625
1626        // Sliced: [null, [], [3, 4]]
1627        let sliced = list_array.slice(1, 3);
1628        let predicate = BooleanArray::from_iter([false, false, true]);
1629
1630        // Filter result: [[1, 2], []]
1631        let filtered = filter(&sliced, &predicate)
1632            .unwrap()
1633            .as_list_view::<T>()
1634            .clone();
1635
1636        let mut expected = GenericListViewBuilder::<T, _>::new(Int32Builder::new());
1637        expected.append_value([Some(3), Some(4)]);
1638        let expected = expected.finish();
1639
1640        assert_eq!(&filtered, &expected);
1641    }
1642
1643    #[test]
1644    fn test_filter_list_view_array() {
1645        test_case_filter_list_view::<i32>();
1646        test_case_filter_list_view::<i64>();
1647
1648        test_case_filter_sliced_list_view::<i32>();
1649        test_case_filter_sliced_list_view::<i64>();
1650    }
1651
1652    #[test]
1653    fn test_slice_iterator_bits() {
1654        let filter_values = (0..64).map(|i| i == 1).collect::<Vec<bool>>();
1655        let filter = BooleanArray::from(filter_values);
1656        let filter_count = filter.true_count();
1657
1658        let iter = SlicesIterator::new(&filter);
1659        let chunks = iter.collect::<Vec<_>>();
1660
1661        assert_eq!(chunks, vec![(1, 2)]);
1662        assert_eq!(filter_count, 1);
1663    }
1664
1665    #[test]
1666    fn test_slice_iterator_bits1() {
1667        let filter_values = (0..64).map(|i| i != 1).collect::<Vec<bool>>();
1668        let filter = BooleanArray::from(filter_values);
1669        let filter_count = filter.true_count();
1670
1671        let iter = SlicesIterator::new(&filter);
1672        let chunks = iter.collect::<Vec<_>>();
1673
1674        assert_eq!(chunks, vec![(0, 1), (2, 64)]);
1675        assert_eq!(filter_count, 64 - 1);
1676    }
1677
1678    #[test]
1679    fn test_slice_iterator_chunk_and_bits() {
1680        let filter_values = (0..130).map(|i| i % 62 != 0).collect::<Vec<bool>>();
1681        let filter = BooleanArray::from(filter_values);
1682        let filter_count = filter.true_count();
1683
1684        let iter = SlicesIterator::new(&filter);
1685        let chunks = iter.collect::<Vec<_>>();
1686
1687        assert_eq!(chunks, vec![(1, 62), (63, 124), (125, 130)]);
1688        assert_eq!(filter_count, 61 + 61 + 5);
1689    }
1690
1691    #[test]
1692    fn test_filter_selection_iterators() {
1693        let slices = [(0, 2), (4, 5)];
1694        let mut ranges = Vec::new();
1695        let selection: FilterSlices<'_> = FilterIterator::Materialized(slices.iter().copied());
1696        selection.for_each(|range| ranges.push(range));
1697        assert_eq!(ranges, slices);
1698
1699        let filter = BooleanArray::from(vec![true, true, false, false, true]);
1700        let mut ranges = Vec::new();
1701        let selection: FilterSlices<'_> = FilterIterator::Lazy(SlicesIterator::new(&filter));
1702        selection
1703            .try_for_each(|range| {
1704                ranges.push(range);
1705                Ok::<(), ArrowError>(())
1706            })
1707            .unwrap();
1708        assert_eq!(ranges, vec![(0, 2), (4, 5)]);
1709
1710        let indices = [1, 3, 5];
1711        let mut selected = Vec::new();
1712        let selection: FilterIndices<'_> = FilterIterator::Materialized(indices.iter().copied());
1713        selection.for_each(|idx| selected.push(idx));
1714        assert_eq!(selected, indices);
1715
1716        let filter = BooleanArray::from(vec![false, true, false, true]);
1717        let mut selected = Vec::new();
1718        let selection: FilterIndices<'_> = FilterIterator::Lazy(IndexIterator::new(&filter, 2));
1719        selection
1720            .try_for_each(|idx| {
1721                selected.push(idx);
1722                Ok::<(), ArrowError>(())
1723            })
1724            .unwrap();
1725        assert_eq!(selected, vec![1, 3]);
1726    }
1727
1728    #[test]
1729    fn test_null_mask() {
1730        let a = Int64Array::from(vec![Some(1), Some(2), None]);
1731
1732        let mask1 = BooleanArray::from(vec![Some(true), Some(true), None]);
1733        let out = filter(&a, &mask1).unwrap();
1734        assert_eq!(out.as_ref(), &a.slice(0, 2));
1735    }
1736
1737    #[test]
1738    fn test_filter_record_batch_no_columns() {
1739        let pred = BooleanArray::from(vec![Some(true), Some(true), None]);
1740        let options = RecordBatchOptions::default().with_row_count(Some(100));
1741        let record_batch =
1742            RecordBatch::try_new_with_options(Arc::new(Schema::empty()), vec![], &options).unwrap();
1743        let out = filter_record_batch(&record_batch, &pred).unwrap();
1744
1745        assert_eq!(out.num_rows(), 2);
1746    }
1747
1748    #[test]
1749    fn test_fast_path() {
1750        let a: PrimitiveArray<Int64Type> = PrimitiveArray::from(vec![Some(1), Some(2), None]);
1751
1752        // all true
1753        let mask = BooleanArray::from(vec![true, true, true]);
1754        let out = filter(&a, &mask).unwrap();
1755        let b = out
1756            .as_any()
1757            .downcast_ref::<PrimitiveArray<Int64Type>>()
1758            .unwrap();
1759        assert_eq!(&a, b);
1760
1761        // all false
1762        let mask = BooleanArray::from(vec![false, false, false]);
1763        let out = filter(&a, &mask).unwrap();
1764        assert_eq!(out.len(), 0);
1765        assert_eq!(out.data_type(), &DataType::Int64);
1766    }
1767
1768    #[test]
1769    fn test_slices() {
1770        // takes up 2 u64s
1771        let bools = std::iter::repeat_n(true, 10)
1772            .chain(std::iter::repeat_n(false, 30))
1773            .chain(std::iter::repeat_n(true, 20))
1774            .chain(std::iter::repeat_n(false, 17))
1775            .chain(std::iter::repeat_n(true, 4));
1776
1777        let bool_array: BooleanArray = bools.map(Some).collect();
1778
1779        let slices: Vec<_> = SlicesIterator::new(&bool_array).collect();
1780        let expected = vec![(0, 10), (40, 60), (77, 81)];
1781        assert_eq!(slices, expected);
1782
1783        // slice with offset and truncated len
1784        let len = bool_array.len();
1785        let sliced_array = bool_array.slice(7, len - 10);
1786        let sliced_array = sliced_array
1787            .as_any()
1788            .downcast_ref::<BooleanArray>()
1789            .unwrap();
1790        let slices: Vec<_> = SlicesIterator::new(sliced_array).collect();
1791        let expected = vec![(0, 3), (33, 53), (70, 71)];
1792        assert_eq!(slices, expected);
1793    }
1794
1795    fn test_slices_fuzz(mask_len: usize, offset: usize, truncate: usize) {
1796        let mut rng = rng();
1797
1798        let bools: Vec<bool> = std::iter::from_fn(|| Some(rng.random()))
1799            .take(mask_len)
1800            .collect();
1801
1802        let buffer = Buffer::from_iter(bools.iter().cloned());
1803
1804        let truncated_length = mask_len - offset - truncate;
1805
1806        let filter = BooleanArray::new(BooleanBuffer::new(buffer, offset, truncated_length), None);
1807
1808        let slice_bits: Vec<_> = SlicesIterator::new(&filter)
1809            .flat_map(|(start, end)| start..end)
1810            .collect();
1811
1812        let count = filter.true_count();
1813        let index_bits: Vec<_> = IndexIterator::new(&filter, count).collect();
1814
1815        let expected_bits: Vec<_> = bools
1816            .iter()
1817            .skip(offset)
1818            .take(truncated_length)
1819            .enumerate()
1820            .flat_map(|(idx, v)| v.then(|| idx))
1821            .collect();
1822
1823        assert_eq!(slice_bits, expected_bits);
1824        assert_eq!(index_bits, expected_bits);
1825    }
1826
1827    #[test]
1828    #[cfg_attr(miri, ignore)]
1829    fn fuzz_test_slices_iterator() {
1830        let mut rng = rng();
1831
1832        let uusize = UniformUsize::new(usize::MIN, usize::MAX).unwrap();
1833        for _ in 0..100 {
1834            let mask_len = rng.random_range(0..1024);
1835            let max_offset = 64.min(mask_len);
1836            let offset = uusize.sample(&mut rng).checked_rem(max_offset).unwrap_or(0);
1837
1838            let max_truncate = 128.min(mask_len - offset);
1839            let truncate = uusize
1840                .sample(&mut rng)
1841                .checked_rem(max_truncate)
1842                .unwrap_or(0);
1843
1844            test_slices_fuzz(mask_len, offset, truncate);
1845        }
1846
1847        test_slices_fuzz(64, 0, 0);
1848        test_slices_fuzz(64, 8, 0);
1849        test_slices_fuzz(64, 8, 8);
1850        test_slices_fuzz(32, 8, 8);
1851        test_slices_fuzz(32, 5, 9);
1852    }
1853
1854    /// Filters `values` by `predicate` using standard rust iterators
1855    fn filter_rust<T>(values: impl IntoIterator<Item = T>, predicate: &[bool]) -> Vec<T> {
1856        values
1857            .into_iter()
1858            .zip(predicate)
1859            .filter(|(_, x)| **x)
1860            .map(|(a, _)| a)
1861            .collect()
1862    }
1863
1864    /// Generates an array of length `len` with `valid_percent` non-null values
1865    fn gen_primitive<T>(len: usize, valid_percent: f64) -> Vec<Option<T>>
1866    where
1867        StandardUniform: Distribution<T>,
1868    {
1869        let mut rng = rng();
1870        (0..len)
1871            .map(|_| rng.random_bool(valid_percent).then(|| rng.random()))
1872            .collect()
1873    }
1874
1875    /// Generates an array of length `len` with `valid_percent` non-null values
1876    fn gen_strings(
1877        len: usize,
1878        valid_percent: f64,
1879        str_len_range: std::ops::Range<usize>,
1880    ) -> Vec<Option<String>> {
1881        let mut rng = rng();
1882        (0..len)
1883            .map(|_| {
1884                rng.random_bool(valid_percent).then(|| {
1885                    let len = rng.random_range(str_len_range.clone());
1886                    (0..len)
1887                        .map(|_| char::from(rng.sample(Alphanumeric)))
1888                        .collect()
1889                })
1890            })
1891            .collect()
1892    }
1893
1894    /// Returns an iterator that calls `Option::as_deref` on each item
1895    fn as_deref<T: std::ops::Deref>(src: &[Option<T>]) -> impl Iterator<Item = Option<&T::Target>> {
1896        src.iter().map(|x| x.as_deref())
1897    }
1898
1899    #[test]
1900    #[cfg_attr(miri, ignore)]
1901    fn fuzz_filter() {
1902        let mut rng = rng();
1903
1904        for i in 0..100 {
1905            let filter_percent = match i {
1906                0..=4 => 1.,
1907                5..=10 => 0.,
1908                _ => rng.random_range(0.0..1.0),
1909            };
1910
1911            let valid_percent = rng.random_range(0.0..1.0);
1912
1913            let array_len = rng.random_range(32..256);
1914            let array_offset = rng.random_range(0..10);
1915
1916            // Construct a predicate
1917            let filter_offset = rng.random_range(0..10);
1918            let filter_truncate = rng.random_range(0..10);
1919            let bools: Vec<_> = std::iter::from_fn(|| Some(rng.random_bool(filter_percent)))
1920                .take(array_len + filter_offset - filter_truncate)
1921                .collect();
1922
1923            let predicate = BooleanArray::from_iter(bools.iter().cloned().map(Some));
1924
1925            // Offset predicate
1926            let predicate = predicate.slice(filter_offset, array_len - filter_truncate);
1927            let predicate = predicate.as_any().downcast_ref::<BooleanArray>().unwrap();
1928            let bools = &bools[filter_offset..];
1929
1930            // Test i32
1931            let values = gen_primitive(array_len + array_offset, valid_percent);
1932            let src = Int32Array::from_iter(values.iter().cloned());
1933
1934            let src = src.slice(array_offset, array_len);
1935            let src = src.as_any().downcast_ref::<Int32Array>().unwrap();
1936            let values = &values[array_offset..];
1937
1938            let filtered = filter(src, predicate).unwrap();
1939            let array = filtered.as_any().downcast_ref::<Int32Array>().unwrap();
1940            let actual: Vec<_> = array.iter().collect();
1941
1942            assert_eq!(actual, filter_rust(values.iter().cloned(), bools));
1943
1944            // Test string
1945            let strings = gen_strings(array_len + array_offset, valid_percent, 0..20);
1946            let src = StringArray::from_iter(as_deref(&strings));
1947
1948            let src = src.slice(array_offset, array_len);
1949            let src = src.as_any().downcast_ref::<StringArray>().unwrap();
1950
1951            let filtered = filter(src, predicate).unwrap();
1952            let array = filtered.as_any().downcast_ref::<StringArray>().unwrap();
1953            let actual: Vec<_> = array.iter().collect();
1954
1955            let expected_strings = filter_rust(as_deref(&strings[array_offset..]), bools);
1956            assert_eq!(actual, expected_strings);
1957
1958            // Test string dictionary
1959            let src = DictionaryArray::<Int32Type>::from_iter(as_deref(&strings));
1960
1961            let src = src.slice(array_offset, array_len);
1962            let src = src
1963                .as_any()
1964                .downcast_ref::<DictionaryArray<Int32Type>>()
1965                .unwrap();
1966
1967            let filtered = filter(src, predicate).unwrap();
1968
1969            let array = filtered
1970                .as_any()
1971                .downcast_ref::<DictionaryArray<Int32Type>>()
1972                .unwrap();
1973
1974            let values = array
1975                .values()
1976                .as_any()
1977                .downcast_ref::<StringArray>()
1978                .unwrap();
1979
1980            let actual: Vec<_> = array
1981                .keys()
1982                .iter()
1983                .map(|key| key.map(|key| values.value(key as usize)))
1984                .collect();
1985
1986            assert_eq!(actual, expected_strings);
1987        }
1988    }
1989
1990    #[test]
1991    fn test_filter_map() {
1992        let mut builder =
1993            MapBuilder::new(None, StringBuilder::new(), Int64Builder::with_capacity(4));
1994        // [{"key1": 1}, {"key2": 2, "key3": 3}, null, {"key1": 1}
1995        builder.keys().append_value("key1");
1996        builder.values().append_value(1);
1997        builder.append(true).unwrap();
1998        builder.keys().append_value("key2");
1999        builder.keys().append_value("key3");
2000        builder.values().append_value(2);
2001        builder.values().append_value(3);
2002        builder.append(true).unwrap();
2003        builder.append(false).unwrap();
2004        builder.keys().append_value("key1");
2005        builder.values().append_value(1);
2006        builder.append(true).unwrap();
2007        let maparray = Arc::new(builder.finish()) as ArrayRef;
2008
2009        let indices = vec![Some(true), Some(false), Some(false), Some(true)]
2010            .into_iter()
2011            .collect::<BooleanArray>();
2012        let got = filter(&maparray, &indices).unwrap();
2013
2014        let mut builder =
2015            MapBuilder::new(None, StringBuilder::new(), Int64Builder::with_capacity(2));
2016        builder.keys().append_value("key1");
2017        builder.values().append_value(1);
2018        builder.append(true).unwrap();
2019        builder.keys().append_value("key1");
2020        builder.values().append_value(1);
2021        builder.append(true).unwrap();
2022        let expected = Arc::new(builder.finish()) as ArrayRef;
2023
2024        assert_eq!(&expected, &got);
2025    }
2026
2027    #[test]
2028    fn test_filter_fixed_size_list_arrays() {
2029        let field = Arc::new(Field::new_list_field(DataType::Int32, false));
2030        let value_array = Arc::new(Int32Array::from_iter_values(0..9));
2031        let array = FixedSizeListArray::new(field, 3, value_array, None);
2032
2033        let filter_array = BooleanArray::from(vec![true, false, false]);
2034
2035        let c = filter(&array, &filter_array).unwrap();
2036        let filtered = c.as_any().downcast_ref::<FixedSizeListArray>().unwrap();
2037
2038        assert_eq!(filtered.len(), 1);
2039
2040        let list = filtered.value(0);
2041        assert_eq!(
2042            &[0, 1, 2],
2043            list.as_any().downcast_ref::<Int32Array>().unwrap().values()
2044        );
2045
2046        let filter_array = BooleanArray::from(vec![true, false, true]);
2047
2048        let c = filter(&array, &filter_array).unwrap();
2049        let filtered = c.as_any().downcast_ref::<FixedSizeListArray>().unwrap();
2050
2051        assert_eq!(filtered.len(), 2);
2052
2053        let list = filtered.value(0);
2054        assert_eq!(
2055            &[0, 1, 2],
2056            list.as_any().downcast_ref::<Int32Array>().unwrap().values()
2057        );
2058        let list = filtered.value(1);
2059        assert_eq!(
2060            &[6, 7, 8],
2061            list.as_any().downcast_ref::<Int32Array>().unwrap().values()
2062        );
2063    }
2064
2065    #[test]
2066    fn test_filter_fixed_size_list_arrays_with_null() {
2067        let field = Arc::new(Field::new_list_field(DataType::Int32, false));
2068        let value_array = Arc::new(Int32Array::from_iter_values(0..10));
2069        let nulls = Some(NullBuffer::from(vec![true, false, false, true, true]));
2070        let array = FixedSizeListArray::new(field, 2, value_array, nulls);
2071
2072        let filter_array = BooleanArray::from(vec![true, true, false, true, false]);
2073
2074        let c = filter(&array, &filter_array).unwrap();
2075        let filtered = c.as_any().downcast_ref::<FixedSizeListArray>().unwrap();
2076
2077        assert_eq!(filtered.len(), 3);
2078
2079        let list = filtered.value(0);
2080        assert_eq!(
2081            &[0, 1],
2082            list.as_any().downcast_ref::<Int32Array>().unwrap().values()
2083        );
2084        assert!(filtered.is_null(1));
2085        let list = filtered.value(2);
2086        assert_eq!(
2087            &[6, 7],
2088            list.as_any().downcast_ref::<Int32Array>().unwrap().values()
2089        );
2090    }
2091
2092    fn test_filter_union_array(array: UnionArray) {
2093        let filter_array = BooleanArray::from(vec![true, false, false]);
2094        let c = filter(&array, &filter_array).unwrap();
2095        let filtered = c.as_any().downcast_ref::<UnionArray>().unwrap();
2096
2097        let mut builder = UnionBuilder::new_dense();
2098        builder.append::<Int32Type>("A", 1).unwrap();
2099        let expected_array = builder.build().unwrap();
2100
2101        compare_union_arrays(filtered, &expected_array);
2102
2103        let filter_array = BooleanArray::from(vec![true, false, true]);
2104        let c = filter(&array, &filter_array).unwrap();
2105        let filtered = c.as_any().downcast_ref::<UnionArray>().unwrap();
2106
2107        let mut builder = UnionBuilder::new_dense();
2108        builder.append::<Int32Type>("A", 1).unwrap();
2109        builder.append::<Int32Type>("A", 34).unwrap();
2110        let expected_array = builder.build().unwrap();
2111
2112        compare_union_arrays(filtered, &expected_array);
2113
2114        let filter_array = BooleanArray::from(vec![true, true, false]);
2115        let c = filter(&array, &filter_array).unwrap();
2116        let filtered = c.as_any().downcast_ref::<UnionArray>().unwrap();
2117
2118        let mut builder = UnionBuilder::new_dense();
2119        builder.append::<Int32Type>("A", 1).unwrap();
2120        builder.append::<Float64Type>("B", 3.2).unwrap();
2121        let expected_array = builder.build().unwrap();
2122
2123        compare_union_arrays(filtered, &expected_array);
2124    }
2125
2126    #[test]
2127    fn test_filter_union_array_dense() {
2128        let mut builder = UnionBuilder::new_dense();
2129        builder.append::<Int32Type>("A", 1).unwrap();
2130        builder.append::<Float64Type>("B", 3.2).unwrap();
2131        builder.append::<Int32Type>("A", 34).unwrap();
2132        let array = builder.build().unwrap();
2133
2134        test_filter_union_array(array);
2135    }
2136
2137    #[test]
2138    fn test_filter_run_union_array_dense() {
2139        let mut builder = UnionBuilder::new_dense();
2140        builder.append::<Int32Type>("A", 1).unwrap();
2141        builder.append::<Int32Type>("A", 3).unwrap();
2142        builder.append::<Int32Type>("A", 34).unwrap();
2143        let array = builder.build().unwrap();
2144
2145        let filter_array = BooleanArray::from(vec![true, true, false]);
2146        let c = filter(&array, &filter_array).unwrap();
2147        let filtered = c.as_any().downcast_ref::<UnionArray>().unwrap();
2148
2149        let mut builder = UnionBuilder::new_dense();
2150        builder.append::<Int32Type>("A", 1).unwrap();
2151        builder.append::<Int32Type>("A", 3).unwrap();
2152        let expected = builder.build().unwrap();
2153
2154        assert_eq!(filtered.to_data(), expected.to_data());
2155    }
2156
2157    #[test]
2158    fn test_filter_union_array_dense_with_nulls() {
2159        let mut builder = UnionBuilder::new_dense();
2160        builder.append::<Int32Type>("A", 1).unwrap();
2161        builder.append::<Float64Type>("B", 3.2).unwrap();
2162        builder.append_null::<Float64Type>("B").unwrap();
2163        builder.append::<Int32Type>("A", 34).unwrap();
2164        let array = builder.build().unwrap();
2165
2166        let filter_array = BooleanArray::from(vec![true, true, false, false]);
2167        let c = filter(&array, &filter_array).unwrap();
2168        let filtered = c.as_any().downcast_ref::<UnionArray>().unwrap();
2169
2170        let mut builder = UnionBuilder::new_dense();
2171        builder.append::<Int32Type>("A", 1).unwrap();
2172        builder.append::<Float64Type>("B", 3.2).unwrap();
2173        let expected_array = builder.build().unwrap();
2174
2175        compare_union_arrays(filtered, &expected_array);
2176
2177        let filter_array = BooleanArray::from(vec![true, false, true, false]);
2178        let c = filter(&array, &filter_array).unwrap();
2179        let filtered = c.as_any().downcast_ref::<UnionArray>().unwrap();
2180
2181        let mut builder = UnionBuilder::new_dense();
2182        builder.append::<Int32Type>("A", 1).unwrap();
2183        builder.append_null::<Float64Type>("B").unwrap();
2184        let expected_array = builder.build().unwrap();
2185
2186        compare_union_arrays(filtered, &expected_array);
2187    }
2188
2189    #[test]
2190    fn test_filter_union_array_sparse() {
2191        let mut builder = UnionBuilder::new_sparse();
2192        builder.append::<Int32Type>("A", 1).unwrap();
2193        builder.append::<Float64Type>("B", 3.2).unwrap();
2194        builder.append::<Int32Type>("A", 34).unwrap();
2195        let array = builder.build().unwrap();
2196
2197        test_filter_union_array(array);
2198    }
2199
2200    #[test]
2201    fn test_filter_union_array_sparse_with_nulls() {
2202        let mut builder = UnionBuilder::new_sparse();
2203        builder.append::<Int32Type>("A", 1).unwrap();
2204        builder.append::<Float64Type>("B", 3.2).unwrap();
2205        builder.append_null::<Float64Type>("B").unwrap();
2206        builder.append::<Int32Type>("A", 34).unwrap();
2207        let array = builder.build().unwrap();
2208
2209        let filter_array = BooleanArray::from(vec![true, false, true, false]);
2210        let c = filter(&array, &filter_array).unwrap();
2211        let filtered = c.as_any().downcast_ref::<UnionArray>().unwrap();
2212
2213        let mut builder = UnionBuilder::new_sparse();
2214        builder.append::<Int32Type>("A", 1).unwrap();
2215        builder.append_null::<Float64Type>("B").unwrap();
2216        let expected_array = builder.build().unwrap();
2217
2218        compare_union_arrays(filtered, &expected_array);
2219    }
2220
2221    fn compare_union_arrays(union1: &UnionArray, union2: &UnionArray) {
2222        assert_eq!(union1.len(), union2.len());
2223
2224        for i in 0..union1.len() {
2225            let type_id = union1.type_id(i);
2226
2227            let slot1 = union1.value(i);
2228            let slot2 = union2.value(i);
2229
2230            assert_eq!(slot1.is_null(0), slot2.is_null(0));
2231
2232            if !slot1.is_null(0) && !slot2.is_null(0) {
2233                match type_id {
2234                    0 => {
2235                        let slot1 = slot1.as_any().downcast_ref::<Int32Array>().unwrap();
2236                        assert_eq!(slot1.len(), 1);
2237                        let value1 = slot1.value(0);
2238
2239                        let slot2 = slot2.as_any().downcast_ref::<Int32Array>().unwrap();
2240                        assert_eq!(slot2.len(), 1);
2241                        let value2 = slot2.value(0);
2242                        assert_eq!(value1, value2);
2243                    }
2244                    1 => {
2245                        let slot1 = slot1.as_any().downcast_ref::<Float64Array>().unwrap();
2246                        assert_eq!(slot1.len(), 1);
2247                        let value1 = slot1.value(0);
2248
2249                        let slot2 = slot2.as_any().downcast_ref::<Float64Array>().unwrap();
2250                        assert_eq!(slot2.len(), 1);
2251                        let value2 = slot2.value(0);
2252                        assert_eq!(value1, value2);
2253                    }
2254                    _ => unreachable!(),
2255                }
2256            }
2257        }
2258    }
2259
2260    #[test]
2261    fn test_filter_struct() {
2262        let predicate = BooleanArray::from(vec![true, false, true, false]);
2263
2264        let a = Arc::new(StringArray::from(vec!["hello", " ", "world", "!"]));
2265        let a_filtered = Arc::new(StringArray::from(vec!["hello", "world"]));
2266
2267        let b = Arc::new(Int32Array::from(vec![5, 6, 7, 8]));
2268        let b_filtered = Arc::new(Int32Array::from(vec![5, 7]));
2269
2270        let null_mask = NullBuffer::from(vec![true, false, false, true]);
2271        let null_mask_filtered = NullBuffer::from(vec![true, false]);
2272
2273        let a_field = Field::new("a", DataType::Utf8, false);
2274        let b_field = Field::new("b", DataType::Int32, false);
2275
2276        let array = StructArray::new(vec![a_field.clone()].into(), vec![a.clone()], None);
2277        let expected =
2278            StructArray::new(vec![a_field.clone()].into(), vec![a_filtered.clone()], None);
2279
2280        let result = filter(&array, &predicate).unwrap();
2281
2282        assert_eq!(result.to_data(), expected.to_data());
2283
2284        let array = StructArray::new(
2285            vec![a_field.clone()].into(),
2286            vec![a.clone()],
2287            Some(null_mask.clone()),
2288        );
2289        let expected = StructArray::new(
2290            vec![a_field.clone()].into(),
2291            vec![a_filtered.clone()],
2292            Some(null_mask_filtered.clone()),
2293        );
2294
2295        let result = filter(&array, &predicate).unwrap();
2296
2297        assert_eq!(result.to_data(), expected.to_data());
2298
2299        let array = StructArray::new(
2300            vec![a_field.clone(), b_field.clone()].into(),
2301            vec![a.clone(), b.clone()],
2302            None,
2303        );
2304        let expected = StructArray::new(
2305            vec![a_field.clone(), b_field.clone()].into(),
2306            vec![a_filtered.clone(), b_filtered.clone()],
2307            None,
2308        );
2309
2310        let result = filter(&array, &predicate).unwrap();
2311
2312        assert_eq!(result.to_data(), expected.to_data());
2313
2314        let array = StructArray::new(
2315            vec![a_field.clone(), b_field.clone()].into(),
2316            vec![a.clone(), b.clone()],
2317            Some(null_mask.clone()),
2318        );
2319
2320        let expected = StructArray::new(
2321            vec![a_field.clone(), b_field.clone()].into(),
2322            vec![a_filtered.clone(), b_filtered.clone()],
2323            Some(null_mask_filtered.clone()),
2324        );
2325
2326        let result = filter(&array, &predicate).unwrap();
2327
2328        assert_eq!(result.to_data(), expected.to_data());
2329    }
2330
2331    #[test]
2332    fn test_filter_empty_struct() {
2333        /*
2334            "a": {
2335                "b": int64,
2336                "c": {}
2337            },
2338        */
2339        let fields = arrow_schema::Field::new(
2340            "a",
2341            arrow_schema::DataType::Struct(arrow_schema::Fields::from(vec![
2342                arrow_schema::Field::new("b", arrow_schema::DataType::Int64, true),
2343                arrow_schema::Field::new(
2344                    "c",
2345                    arrow_schema::DataType::Struct(arrow_schema::Fields::empty()),
2346                    true,
2347                ),
2348            ])),
2349            true,
2350        );
2351
2352        /* Test record
2353            {"a":{"c": {}}}
2354            {"a":{"c": {}}}
2355            {"a":{"c": {}}}
2356        */
2357
2358        // Create the record batch with the nested struct array
2359        let schema = Arc::new(Schema::new(vec![fields]));
2360
2361        let b = Arc::new(Int64Array::from(vec![None, None, None]));
2362        let c = Arc::new(StructArray::new_empty_fields(
2363            3,
2364            Some(NullBuffer::from(vec![true, true, true])),
2365        ));
2366        let a = StructArray::new(
2367            vec![
2368                Field::new("b", DataType::Int64, true),
2369                Field::new("c", DataType::Struct(Fields::empty()), true),
2370            ]
2371            .into(),
2372            vec![b.clone(), c.clone()],
2373            Some(NullBuffer::from(vec![true, true, true])),
2374        );
2375        let record_batch = RecordBatch::try_new(schema, vec![Arc::new(a)]).unwrap();
2376        println!("{record_batch:?}");
2377
2378        // Apply the filter
2379        let predicate = BooleanArray::from(vec![true, false, true]);
2380        let filtered_batch = filter_record_batch(&record_batch, &predicate).unwrap();
2381
2382        // The filtered batch should have 2 rows (the 1st and 3rd)
2383        assert_eq!(filtered_batch.num_rows(), 2);
2384    }
2385
2386    #[test]
2387    #[should_panic]
2388    fn test_filter_bits_too_large() {
2389        let buffer = BooleanBuffer::from(vec![false; 8]);
2390        let predicate = BooleanArray::from(vec![true; 9]);
2391        let filter = FilterBuilder::new(&predicate).build();
2392        filter_bits(&buffer, &filter);
2393    }
2394
2395    #[test]
2396    #[should_panic]
2397    fn test_filter_native_too_large() {
2398        let values = vec![1; 8];
2399        let predicate = BooleanArray::from(vec![false; 9]);
2400        let filter = FilterBuilder::new(&predicate).build();
2401        filter_native(&values, &filter);
2402    }
2403}