arrow_array/builder/
generic_bytes_builder.rs

1// Licensed to the Apache Software Foundation (ASF) under one
2// or more contributor license agreements.  See the NOTICE file
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4// regarding copyright ownership.  The ASF licenses this file
5// to you under the Apache License, Version 2.0 (the
6// "License"); you may not use this file except in compliance
7// with the License.  You may obtain a copy of the License at
8//
9//   http://www.apache.org/licenses/LICENSE-2.0
10//
11// Unless required by applicable law or agreed to in writing,
12// software distributed under the License is distributed on an
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14// KIND, either express or implied.  See the License for the
15// specific language governing permissions and limitations
16// under the License.
17
18use crate::builder::ArrayBuilder;
19use crate::types::{ByteArrayType, GenericBinaryType, GenericStringType};
20use crate::{Array, ArrayRef, GenericByteArray, OffsetSizeTrait};
21use arrow_buffer::{ArrowNativeType, Buffer, MutableBuffer, NullBufferBuilder, ScalarBuffer};
22use arrow_data::ArrayDataBuilder;
23use arrow_schema::ArrowError;
24use std::any::Any;
25use std::sync::Arc;
26
27/// Builder for [`GenericByteArray`]
28///
29/// For building strings, see docs on [`GenericStringBuilder`].
30/// For building binary, see docs on [`GenericBinaryBuilder`].
31pub struct GenericByteBuilder<T: ByteArrayType> {
32    value_builder: Vec<u8>,
33    offsets_builder: Vec<T::Offset>,
34    null_buffer_builder: NullBufferBuilder,
35}
36
37impl<T: ByteArrayType> GenericByteBuilder<T> {
38    /// Creates a new [`GenericByteBuilder`].
39    pub fn new() -> Self {
40        Self::with_capacity(1024, 1024)
41    }
42
43    /// Creates a new [`GenericByteBuilder`].
44    ///
45    /// - `item_capacity` is the number of items to pre-allocate.
46    ///   The size of the preallocated buffer of offsets is the number of items plus one.
47    /// - `data_capacity` is the total number of bytes of data to pre-allocate
48    ///   (for all items, not per item).
49    pub fn with_capacity(item_capacity: usize, data_capacity: usize) -> Self {
50        let mut offsets_builder = Vec::with_capacity(item_capacity + 1);
51        offsets_builder.push(T::Offset::from_usize(0).unwrap());
52        Self {
53            value_builder: Vec::with_capacity(data_capacity),
54            offsets_builder,
55            null_buffer_builder: NullBufferBuilder::new(item_capacity),
56        }
57    }
58
59    /// Creates a new  [`GenericByteBuilder`] from buffers.
60    ///
61    /// # Safety
62    ///
63    /// This doesn't verify buffer contents as it assumes the buffers are from
64    /// existing and valid [`GenericByteArray`].
65    pub unsafe fn new_from_buffer(
66        offsets_buffer: MutableBuffer,
67        value_buffer: MutableBuffer,
68        null_buffer: Option<MutableBuffer>,
69    ) -> Self {
70        let offsets_builder: Vec<T::Offset> =
71            ScalarBuffer::<T::Offset>::from(offsets_buffer).into();
72        let value_builder: Vec<u8> = ScalarBuffer::<u8>::from(value_buffer).into();
73
74        let null_buffer_builder = null_buffer
75            .map(|buffer| NullBufferBuilder::new_from_buffer(buffer, offsets_builder.len() - 1))
76            .unwrap_or_else(|| NullBufferBuilder::new_with_len(offsets_builder.len() - 1));
77
78        Self {
79            value_builder,
80            offsets_builder,
81            null_buffer_builder,
82        }
83    }
84
85    #[inline]
86    fn next_offset(&self) -> T::Offset {
87        T::Offset::from_usize(self.value_builder.len()).expect("byte array offset overflow")
88    }
89
90    /// Appends a value into the builder.
91    ///
92    /// See the [GenericStringBuilder] documentation for examples of
93    /// incrementally building string values with multiple `write!` calls.
94    ///
95    /// # Panics
96    ///
97    /// Panics if the resulting length of [`Self::values_slice`] would exceed
98    /// `T::Offset::MAX` bytes.
99    ///
100    /// For example, this can happen with [`StringArray`] or [`BinaryArray`]
101    /// where the total length of all values exceeds 2GB
102    ///
103    /// [`StringArray`]: crate::StringArray
104    /// [`BinaryArray`]: crate::BinaryArray
105    #[inline]
106    pub fn append_value(&mut self, value: impl AsRef<T::Native>) {
107        self.value_builder
108            .extend_from_slice(value.as_ref().as_ref());
109        self.null_buffer_builder.append(true);
110        self.offsets_builder.push(self.next_offset());
111    }
112
113    /// Appends a value of type `T` into the builder `n` times.
114    ///
115    /// See [`Self::append_value`] for more panic information.
116    ///
117    /// # Panics
118    ///
119    /// Panics for the same reasons as [`Self::append_value`]
120    #[inline]
121    pub fn append_value_n(&mut self, value: impl AsRef<T::Native>, n: usize) {
122        let bytes: &[u8] = value.as_ref().as_ref();
123        self.value_builder.reserve(bytes.len() * n);
124        self.offsets_builder.reserve(n);
125        for _ in 0..n {
126            self.value_builder.extend_from_slice(bytes);
127            self.offsets_builder.push(self.next_offset());
128        }
129        self.null_buffer_builder.append_n_non_nulls(n);
130    }
131
132    /// Append an `Option` value into the builder.
133    ///
134    /// - A `None` value will append a null value.
135    /// - A `Some` value will append the value.
136    ///
137    /// See [`Self::append_value`] for more panic information.
138    ///
139    /// # Panics
140    ///
141    /// Panics for the same reasons as [`Self::append_value`]
142    #[inline]
143    pub fn append_option(&mut self, value: Option<impl AsRef<T::Native>>) {
144        match value {
145            None => self.append_null(),
146            Some(v) => self.append_value(v),
147        };
148    }
149
150    /// Append a null value into the builder.
151    #[inline]
152    pub fn append_null(&mut self) {
153        self.null_buffer_builder.append(false);
154        self.offsets_builder.push(self.next_offset());
155    }
156
157    /// Appends `n` `null`s into the builder.
158    #[inline]
159    pub fn append_nulls(&mut self, n: usize) {
160        self.null_buffer_builder.append_n_nulls(n);
161        let next_offset = self.next_offset();
162        self.offsets_builder
163            .extend(std::iter::repeat_n(next_offset, n));
164    }
165
166    /// Appends array values and null to this builder as is
167    /// (this means that underlying null values are copied as is).
168    #[inline]
169    pub fn append_array(&mut self, array: &GenericByteArray<T>) -> Result<(), ArrowError> {
170        use num_traits::CheckedAdd;
171        if array.len() == 0 {
172            return Ok(());
173        }
174
175        let offsets = array.offsets();
176
177        // If the offsets are contiguous, we can append them directly avoiding the need to align
178        // for example, when the first appended array is not sliced (starts at offset 0)
179        if self.next_offset() == offsets[0] {
180            self.offsets_builder.extend_from_slice(&offsets[1..]);
181        } else {
182            // Shifting all the offsets
183            let shift: T::Offset = self.next_offset() - offsets[0];
184
185            if shift.checked_add(&offsets[offsets.len() - 1]).is_none() {
186                return Err(ArrowError::OffsetOverflowError(
187                    shift.as_usize() + offsets[offsets.len() - 1].as_usize(),
188                ));
189            }
190
191            self.offsets_builder
192                .extend(offsets[1..].iter().map(|&offset| offset + shift));
193        }
194
195        // Append underlying values, starting from the first offset and ending at the last offset
196        self.value_builder.extend_from_slice(
197            &array.values().as_slice()[offsets[0].as_usize()..offsets[array.len()].as_usize()],
198        );
199
200        if let Some(null_buffer) = array.nulls() {
201            self.null_buffer_builder.append_buffer(null_buffer);
202        } else {
203            self.null_buffer_builder.append_n_non_nulls(array.len());
204        }
205        Ok(())
206    }
207
208    /// Builds the [`GenericByteArray`] and reset this builder.
209    pub fn finish(&mut self) -> GenericByteArray<T> {
210        let array_type = T::DATA_TYPE;
211        let array_builder = ArrayDataBuilder::new(array_type)
212            .len(self.len())
213            .add_buffer(std::mem::take(&mut self.offsets_builder).into())
214            .add_buffer(std::mem::take(&mut self.value_builder).into())
215            .nulls(self.null_buffer_builder.finish());
216
217        self.offsets_builder.push(self.next_offset());
218        let array_data = unsafe { array_builder.build_unchecked() };
219        GenericByteArray::from(array_data)
220    }
221
222    /// Builds the [`GenericByteArray`] without resetting the builder.
223    pub fn finish_cloned(&self) -> GenericByteArray<T> {
224        let array_type = T::DATA_TYPE;
225        let offset_buffer = Buffer::from_slice_ref(self.offsets_builder.as_slice());
226        let value_buffer = Buffer::from_slice_ref(self.value_builder.as_slice());
227        let array_builder = ArrayDataBuilder::new(array_type)
228            .len(self.len())
229            .add_buffer(offset_buffer)
230            .add_buffer(value_buffer)
231            .nulls(self.null_buffer_builder.finish_cloned());
232
233        let array_data = unsafe { array_builder.build_unchecked() };
234        GenericByteArray::from(array_data)
235    }
236
237    /// Returns the current values buffer as a slice
238    pub fn values_slice(&self) -> &[u8] {
239        self.value_builder.as_slice()
240    }
241
242    /// Returns the current values buffer capacity, in bytes.
243    pub fn values_capacity(&self) -> usize {
244        self.value_builder.capacity()
245    }
246
247    /// Returns the current offsets buffer as a slice
248    pub fn offsets_slice(&self) -> &[T::Offset] {
249        self.offsets_builder.as_slice()
250    }
251
252    /// Returns the current offsets buffer capacity, in offsets.
253    pub fn offsets_capacity(&self) -> usize {
254        self.offsets_builder.capacity()
255    }
256
257    /// Returns the current null buffer as a slice
258    pub fn validity_slice(&self) -> Option<&[u8]> {
259        self.null_buffer_builder.as_slice()
260    }
261
262    /// Returns the current null buffer allocated capacity, in bytes.
263    pub fn validity_capacity(&self) -> usize {
264        self.null_buffer_builder.allocated_size()
265    }
266
267    /// Returns the current null buffer as a mutable slice
268    pub fn validity_slice_mut(&mut self) -> Option<&mut [u8]> {
269        self.null_buffer_builder.as_slice_mut()
270    }
271}
272
273impl<T: ByteArrayType> std::fmt::Debug for GenericByteBuilder<T> {
274    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
275        write!(f, "{}{}Builder", T::Offset::PREFIX, T::PREFIX)?;
276        f.debug_struct("")
277            .field("value_builder", &self.value_builder)
278            .field("offsets_builder", &self.offsets_builder)
279            .field("null_buffer_builder", &self.null_buffer_builder)
280            .finish()
281    }
282}
283
284impl<T: ByteArrayType> Default for GenericByteBuilder<T> {
285    fn default() -> Self {
286        Self::new()
287    }
288}
289
290impl<T: ByteArrayType> ArrayBuilder for GenericByteBuilder<T> {
291    /// Returns the number of binary slots in the builder
292    fn len(&self) -> usize {
293        self.null_buffer_builder.len()
294    }
295
296    /// Builds the array and reset this builder.
297    fn finish(&mut self) -> ArrayRef {
298        Arc::new(self.finish())
299    }
300
301    /// Builds the array without resetting the builder.
302    fn finish_cloned(&self) -> ArrayRef {
303        Arc::new(self.finish_cloned())
304    }
305
306    /// Returns the builder as a non-mutable `Any` reference.
307    fn as_any(&self) -> &dyn Any {
308        self
309    }
310
311    /// Returns the builder as a mutable `Any` reference.
312    fn as_any_mut(&mut self) -> &mut dyn Any {
313        self
314    }
315
316    /// Returns the boxed builder as a box of `Any`.
317    fn into_box_any(self: Box<Self>) -> Box<dyn Any> {
318        self
319    }
320}
321
322impl<T: ByteArrayType, V: AsRef<T::Native>> Extend<Option<V>> for GenericByteBuilder<T> {
323    #[inline]
324    fn extend<I: IntoIterator<Item = Option<V>>>(&mut self, iter: I) {
325        for v in iter {
326            self.append_option(v)
327        }
328    }
329}
330
331/// Array builder for [`GenericStringArray`][crate::GenericStringArray]
332///
333/// Values can be appended using [`GenericByteBuilder::append_value`], and nulls with
334/// [`GenericByteBuilder::append_null`].
335///
336/// This builder also implements [`std::fmt::Write`] with any written data
337/// included in the next appended value. This allows using [`std::fmt::Display`]
338/// with standard Rust idioms like `write!` and `writeln!` to write data
339/// directly to the builder without intermediate allocations.
340///
341/// # Example writing strings with `append_value`
342/// ```
343/// # use arrow_array::builder::GenericStringBuilder;
344/// let mut builder = GenericStringBuilder::<i32>::new();
345///
346/// // Write one string value
347/// builder.append_value("foobarbaz");
348///
349/// // Write a second string
350/// builder.append_value("v2");
351///
352/// let array = builder.finish();
353/// assert_eq!(array.value(0), "foobarbaz");
354/// assert_eq!(array.value(1), "v2");
355/// ```
356///
357/// # Example incrementally writing strings with `std::fmt::Write`
358///
359/// ```
360/// # use std::fmt::Write;
361/// # use arrow_array::builder::GenericStringBuilder;
362/// let mut builder = GenericStringBuilder::<i32>::new();
363///
364/// // Write data in multiple `write!` calls
365/// write!(builder, "foo").unwrap();
366/// write!(builder, "bar").unwrap();
367/// // The next call to append_value finishes the current string
368/// // including all previously written strings.
369/// builder.append_value("baz");
370///
371/// // Write second value with a single write call
372/// write!(builder, "v2").unwrap();
373/// // finish the value by calling append_value with an empty string
374/// builder.append_value("");
375///
376/// let array = builder.finish();
377/// assert_eq!(array.value(0), "foobarbaz");
378/// assert_eq!(array.value(1), "v2");
379/// ```
380pub type GenericStringBuilder<O> = GenericByteBuilder<GenericStringType<O>>;
381
382impl<O: OffsetSizeTrait> std::fmt::Write for GenericStringBuilder<O> {
383    fn write_str(&mut self, s: &str) -> std::fmt::Result {
384        self.value_builder.extend_from_slice(s.as_bytes());
385        Ok(())
386    }
387}
388
389/// A byte size value representing the number of bytes to allocate per string in [`GenericStringBuilder`]
390///
391/// To create a [`GenericStringBuilder`] using `.with_capacity` we are required to provide: \
392/// - `item_capacity` - the row count \
393/// - `data_capacity` - total string byte count \
394///
395/// We will use the `AVERAGE_STRING_LENGTH` * row_count for `data_capacity`. \
396///
397/// These capacities are preallocation hints used to improve performance,
398/// but consequences of passing a hint too large or too small should be negligible.
399const AVERAGE_STRING_LENGTH: usize = 16;
400/// Trait for string-like array builders
401///
402/// This trait provides unified interface for builders that append string-like data
403/// such as [`GenericStringBuilder<O>`] and [`crate::builder::StringViewBuilder`]
404pub trait StringLikeArrayBuilder: ArrayBuilder {
405    /// Returns a human-readable type name for the builder.
406    fn type_name() -> &'static str;
407
408    /// Creates a new builder with the given row capacity.
409    fn with_capacity(capacity: usize) -> Self;
410
411    /// Appends a non-null string value to the builder.
412    fn append_value(&mut self, value: &str);
413
414    /// Appends a null value to the builder.
415    fn append_null(&mut self);
416}
417
418impl<O: OffsetSizeTrait> StringLikeArrayBuilder for GenericStringBuilder<O> {
419    fn type_name() -> &'static str {
420        std::any::type_name::<Self>()
421    }
422    fn with_capacity(capacity: usize) -> Self {
423        Self::with_capacity(capacity, capacity * AVERAGE_STRING_LENGTH)
424    }
425    fn append_value(&mut self, value: &str) {
426        Self::append_value(self, value);
427    }
428    fn append_null(&mut self) {
429        Self::append_null(self);
430    }
431}
432
433/// A byte size value representing the number of bytes to allocate per binary in [`GenericBinaryBuilder`]
434///
435/// To create a [`GenericBinaryBuilder`] using `.with_capacity` we are required to provide: \
436/// - `item_capacity` - the row count \
437/// - `data_capacity` - total binary byte count \
438///
439/// We will use the `AVERAGE_BINARY_LENGTH` * row_count for `data_capacity`. \
440///
441/// These capacities are preallocation hints used to improve performance,
442/// but consequences of passing a hint too large or too small should be negligible.
443const AVERAGE_BINARY_LENGTH: usize = 128;
444/// Trait for binary-like array builders
445///
446/// This trait provides unified interface for builders that append binary-like data
447/// such as [`GenericBinaryBuilder<O>`] and [`crate::builder::BinaryViewBuilder`]
448pub trait BinaryLikeArrayBuilder: ArrayBuilder {
449    /// Returns a human-readable type name for the builder.
450    fn type_name() -> &'static str;
451
452    /// Creates a new builder with the given row capacity.
453    fn with_capacity(capacity: usize) -> Self;
454
455    /// Appends a non-null string value to the builder.
456    fn append_value(&mut self, value: &[u8]);
457
458    /// Appends a null value to the builder.
459    fn append_null(&mut self);
460}
461
462impl<O: OffsetSizeTrait> BinaryLikeArrayBuilder for GenericBinaryBuilder<O> {
463    fn type_name() -> &'static str {
464        std::any::type_name::<Self>()
465    }
466    fn with_capacity(capacity: usize) -> Self {
467        Self::with_capacity(capacity, capacity * AVERAGE_BINARY_LENGTH)
468    }
469    fn append_value(&mut self, value: &[u8]) {
470        Self::append_value(self, value);
471    }
472    fn append_null(&mut self) {
473        Self::append_null(self);
474    }
475}
476
477///  Array builder for [`GenericBinaryArray`][crate::GenericBinaryArray]
478///
479/// Values can be appended using [`GenericByteBuilder::append_value`], and nulls with
480/// [`GenericByteBuilder::append_null`].
481///
482/// # Example
483/// ```
484/// # use arrow_array::builder::GenericBinaryBuilder;
485/// let mut builder = GenericBinaryBuilder::<i32>::new();
486///
487/// // Write data
488/// builder.append_value("foo");
489///
490/// // Write second value
491/// builder.append_value(&[0,1,2]);
492///
493/// let array = builder.finish();
494/// // binary values
495/// assert_eq!(array.value(0), b"foo");
496/// assert_eq!(array.value(1), b"\x00\x01\x02");
497/// ```
498///
499/// # Example incrementally writing bytes with `write_bytes`
500///
501/// ```
502/// # use std::io::Write;
503/// # use arrow_array::builder::GenericBinaryBuilder;
504/// let mut builder = GenericBinaryBuilder::<i32>::new();
505///
506/// // Write data in multiple `write_bytes` calls
507/// write!(builder, "foo").unwrap();
508/// write!(builder, "bar").unwrap();
509/// // The next call to append_value finishes the current string
510/// // including all previously written strings.
511/// builder.append_value("baz");
512///
513/// // Write second value with a single write call
514/// write!(builder, "v2").unwrap();
515/// // finish the value by calling append_value with an empty string
516/// builder.append_value("");
517///
518/// let array = builder.finish();
519/// assert_eq!(array.value(0), "foobarbaz".as_bytes());
520/// assert_eq!(array.value(1), "v2".as_bytes());
521/// ```
522pub type GenericBinaryBuilder<O> = GenericByteBuilder<GenericBinaryType<O>>;
523
524impl<O: OffsetSizeTrait> std::io::Write for GenericBinaryBuilder<O> {
525    fn write(&mut self, bs: &[u8]) -> std::io::Result<usize> {
526        self.value_builder.extend_from_slice(bs);
527        Ok(bs.len())
528    }
529
530    fn flush(&mut self) -> std::io::Result<()> {
531        Ok(())
532    }
533}
534
535#[cfg(test)]
536mod tests {
537    use super::*;
538    use crate::GenericStringArray;
539    use crate::array::Array;
540    use arrow_buffer::NullBuffer;
541    use std::fmt::Write as _;
542    use std::io::Write as _;
543
544    fn _test_generic_binary_builder<O: OffsetSizeTrait>() {
545        let mut builder = GenericBinaryBuilder::<O>::new();
546
547        builder.append_value(b"hello");
548        builder.append_value(b"");
549        builder.append_null();
550        builder.append_value(b"rust");
551
552        let array = builder.finish();
553
554        assert_eq!(4, array.len());
555        assert_eq!(1, array.null_count());
556        assert_eq!(b"hello", array.value(0));
557        assert_eq!([] as [u8; 0], array.value(1));
558        assert!(array.is_null(2));
559        assert_eq!(b"rust", array.value(3));
560        assert_eq!(O::from_usize(5).unwrap(), array.value_offsets()[2]);
561        assert_eq!(O::from_usize(4).unwrap(), array.value_length(3));
562    }
563
564    #[test]
565    fn test_binary_builder() {
566        _test_generic_binary_builder::<i32>()
567    }
568
569    #[test]
570    fn test_large_binary_builder() {
571        _test_generic_binary_builder::<i64>()
572    }
573
574    fn _test_generic_binary_builder_all_nulls<O: OffsetSizeTrait>() {
575        let mut builder = GenericBinaryBuilder::<O>::new();
576        builder.append_null();
577        builder.append_null();
578        builder.append_null();
579        builder.append_nulls(2);
580        assert_eq!(5, builder.len());
581        assert!(!builder.is_empty());
582
583        let array = builder.finish();
584        assert_eq!(5, array.null_count());
585        assert_eq!(5, array.len());
586        assert!(array.is_null(0));
587        assert!(array.is_null(1));
588        assert!(array.is_null(2));
589        assert!(array.is_null(3));
590        assert!(array.is_null(4));
591    }
592
593    #[test]
594    fn test_binary_builder_all_nulls() {
595        _test_generic_binary_builder_all_nulls::<i32>()
596    }
597
598    #[test]
599    fn test_large_binary_builder_all_nulls() {
600        _test_generic_binary_builder_all_nulls::<i64>()
601    }
602
603    fn _test_generic_binary_builder_reset<O: OffsetSizeTrait>() {
604        let mut builder = GenericBinaryBuilder::<O>::new();
605
606        builder.append_value(b"hello");
607        builder.append_value(b"");
608        builder.append_null();
609        builder.append_value(b"rust");
610        builder.finish();
611
612        assert!(builder.is_empty());
613
614        builder.append_value(b"parquet");
615        builder.append_null();
616        builder.append_value(b"arrow");
617        builder.append_value(b"");
618        builder.append_nulls(2);
619        builder.append_value(b"hi");
620        let array = builder.finish();
621
622        assert_eq!(7, array.len());
623        assert_eq!(3, array.null_count());
624        assert_eq!(b"parquet", array.value(0));
625        assert!(array.is_null(1));
626        assert!(array.is_null(4));
627        assert!(array.is_null(5));
628        assert_eq!(b"arrow", array.value(2));
629        assert_eq!(b"", array.value(1));
630        assert_eq!(b"hi", array.value(6));
631
632        assert_eq!(O::zero(), array.value_offsets()[0]);
633        assert_eq!(O::from_usize(7).unwrap(), array.value_offsets()[2]);
634        assert_eq!(O::from_usize(14).unwrap(), array.value_offsets()[7]);
635        assert_eq!(O::from_usize(5).unwrap(), array.value_length(2));
636    }
637
638    #[test]
639    fn test_binary_builder_reset() {
640        _test_generic_binary_builder_reset::<i32>()
641    }
642
643    #[test]
644    fn test_large_binary_builder_reset() {
645        _test_generic_binary_builder_reset::<i64>()
646    }
647
648    fn _test_generic_string_array_builder<O: OffsetSizeTrait>() {
649        let mut builder = GenericStringBuilder::<O>::new();
650        let owned = "arrow".to_owned();
651
652        builder.append_value("hello");
653        builder.append_value("");
654        builder.append_value(&owned);
655        builder.append_null();
656        builder.append_option(Some("rust"));
657        builder.append_option(None::<&str>);
658        builder.append_option(None::<String>);
659        builder.append_nulls(2);
660        builder.append_value("parquet");
661        assert_eq!(10, builder.len());
662
663        assert_eq!(
664            GenericStringArray::<O>::from(vec![
665                Some("hello"),
666                Some(""),
667                Some("arrow"),
668                None,
669                Some("rust"),
670                None,
671                None,
672                None,
673                None,
674                Some("parquet")
675            ]),
676            builder.finish()
677        );
678    }
679
680    #[test]
681    fn test_string_array_builder() {
682        _test_generic_string_array_builder::<i32>()
683    }
684
685    #[test]
686    fn test_large_string_array_builder() {
687        _test_generic_string_array_builder::<i64>()
688    }
689
690    fn _test_generic_string_array_builder_finish<O: OffsetSizeTrait>() {
691        let mut builder = GenericStringBuilder::<O>::with_capacity(3, 11);
692
693        builder.append_value("hello");
694        builder.append_value("rust");
695        builder.append_null();
696
697        builder.finish();
698        assert!(builder.is_empty());
699        assert_eq!(&[O::zero()], builder.offsets_slice());
700
701        builder.append_value("arrow");
702        builder.append_value("parquet");
703        let arr = builder.finish();
704        // array should not have null buffer because there is not `null` value.
705        assert!(arr.nulls().is_none());
706        assert_eq!(GenericStringArray::<O>::from(vec!["arrow", "parquet"]), arr,)
707    }
708
709    #[test]
710    fn test_string_array_builder_finish() {
711        _test_generic_string_array_builder_finish::<i32>()
712    }
713
714    #[test]
715    fn test_large_string_array_builder_finish() {
716        _test_generic_string_array_builder_finish::<i64>()
717    }
718
719    fn _test_generic_string_array_builder_finish_cloned<O: OffsetSizeTrait>() {
720        let mut builder = GenericStringBuilder::<O>::with_capacity(3, 11);
721
722        builder.append_value("hello");
723        builder.append_value("rust");
724        builder.append_null();
725
726        let mut arr = builder.finish_cloned();
727        assert!(!builder.is_empty());
728        assert_eq!(3, arr.len());
729
730        builder.append_value("arrow");
731        builder.append_value("parquet");
732        arr = builder.finish();
733
734        assert!(arr.nulls().is_some());
735        assert_eq!(&[O::zero()], builder.offsets_slice());
736        assert_eq!(5, arr.len());
737    }
738
739    #[test]
740    fn test_string_array_builder_finish_cloned() {
741        _test_generic_string_array_builder_finish_cloned::<i32>()
742    }
743
744    #[test]
745    fn test_large_string_array_builder_finish_cloned() {
746        _test_generic_string_array_builder_finish_cloned::<i64>()
747    }
748
749    #[test]
750    fn test_extend() {
751        let mut builder = GenericStringBuilder::<i32>::new();
752        builder.extend(["a", "b", "c", "", "a", "b", "c"].into_iter().map(Some));
753        builder.extend(["d", "cupcakes", "hello"].into_iter().map(Some));
754        let array = builder.finish();
755        assert_eq!(array.value_offsets(), &[0, 1, 2, 3, 3, 4, 5, 6, 7, 15, 20]);
756        assert_eq!(array.value_data(), b"abcabcdcupcakeshello");
757    }
758
759    #[test]
760    fn test_write_str() {
761        let mut builder = GenericStringBuilder::<i32>::new();
762        write!(builder, "foo").unwrap();
763        builder.append_value("");
764        writeln!(builder, "bar").unwrap();
765        builder.append_value("");
766        write!(builder, "fiz").unwrap();
767        write!(builder, "buz").unwrap();
768        builder.append_value("");
769        let a = builder.finish();
770        let r: Vec<_> = a.iter().flatten().collect();
771        assert_eq!(r, &["foo", "bar\n", "fizbuz"])
772    }
773
774    #[test]
775    fn test_write_bytes() {
776        let mut builder = GenericBinaryBuilder::<i32>::new();
777        write!(builder, "foo").unwrap();
778        builder.append_value("");
779        writeln!(builder, "bar").unwrap();
780        builder.append_value("");
781        write!(builder, "fiz").unwrap();
782        write!(builder, "buz").unwrap();
783        builder.append_value("");
784        let a = builder.finish();
785        let r: Vec<_> = a.iter().flatten().collect();
786        assert_eq!(
787            r,
788            &["foo".as_bytes(), "bar\n".as_bytes(), "fizbuz".as_bytes()]
789        )
790    }
791
792    #[test]
793    fn test_append_array_without_nulls() {
794        let input = vec![
795            "hello", "world", "how", "are", "you", "doing", "today", "I", "am", "doing", "well",
796            "thank", "you", "for", "asking",
797        ];
798        let arr1 = GenericStringArray::<i32>::from(input[..3].to_vec());
799        let arr2 = GenericStringArray::<i32>::from(input[3..7].to_vec());
800        let arr3 = GenericStringArray::<i32>::from(input[7..].to_vec());
801
802        let mut builder = GenericStringBuilder::<i32>::new();
803        builder.append_array(&arr1).unwrap();
804        builder.append_array(&arr2).unwrap();
805        builder.append_array(&arr3).unwrap();
806
807        let actual = builder.finish();
808        let expected = GenericStringArray::<i32>::from(input);
809
810        assert_eq!(actual, expected);
811    }
812
813    #[test]
814    fn test_append_array_with_nulls() {
815        let input = vec![
816            Some("hello"),
817            None,
818            Some("how"),
819            None,
820            None,
821            None,
822            None,
823            Some("I"),
824            Some("am"),
825            Some("doing"),
826            Some("well"),
827        ];
828        let arr1 = GenericStringArray::<i32>::from(input[..3].to_vec());
829        let arr2 = GenericStringArray::<i32>::from(input[3..7].to_vec());
830        let arr3 = GenericStringArray::<i32>::from(input[7..].to_vec());
831
832        let mut builder = GenericStringBuilder::<i32>::new();
833        builder.append_array(&arr1).unwrap();
834        builder.append_array(&arr2).unwrap();
835        builder.append_array(&arr3).unwrap();
836
837        let actual = builder.finish();
838        let expected = GenericStringArray::<i32>::from(input);
839
840        assert_eq!(actual, expected);
841    }
842
843    #[test]
844    fn test_append_empty_array() {
845        let arr = GenericStringArray::<i32>::from(Vec::<&str>::new());
846        let mut builder = GenericStringBuilder::<i32>::new();
847        builder.append_array(&arr).unwrap();
848        let result = builder.finish();
849        assert_eq!(result.len(), 0);
850    }
851
852    #[test]
853    fn test_append_array_with_offset_not_starting_at_0() {
854        let input = vec![
855            Some("hello"),
856            None,
857            Some("how"),
858            None,
859            None,
860            None,
861            None,
862            Some("I"),
863            Some("am"),
864            Some("doing"),
865            Some("well"),
866        ];
867        let full_array = GenericStringArray::<i32>::from(input);
868        let sliced = full_array.slice(1, 4);
869
870        assert_ne!(sliced.offsets()[0].as_usize(), 0);
871        assert_ne!(sliced.offsets().last(), full_array.offsets().last());
872
873        let mut builder = GenericStringBuilder::<i32>::new();
874        builder.append_array(&sliced).unwrap();
875        let actual = builder.finish();
876
877        let expected = GenericStringArray::<i32>::from(vec![None, Some("how"), None, None]);
878
879        assert_eq!(actual, expected);
880    }
881
882    #[test]
883    fn test_append_underlying_null_values_added_as_is() {
884        let input_1_array_with_nulls = {
885            let input = vec![
886                "hello", "world", "how", "are", "you", "doing", "today", "I", "am",
887            ];
888            let (offsets, buffer, _) = GenericStringArray::<i32>::from(input).into_parts();
889
890            GenericStringArray::<i32>::new(
891                offsets,
892                buffer,
893                Some(NullBuffer::from(&[
894                    true, false, true, false, false, true, true, true, false,
895                ])),
896            )
897        };
898        let input_2_array_with_nulls = {
899            let input = vec!["doing", "well", "thank", "you", "for", "asking"];
900            let (offsets, buffer, _) = GenericStringArray::<i32>::from(input).into_parts();
901
902            GenericStringArray::<i32>::new(
903                offsets,
904                buffer,
905                Some(NullBuffer::from(&[false, false, true, false, true, true])),
906            )
907        };
908
909        let mut builder = GenericStringBuilder::<i32>::new();
910        builder.append_array(&input_1_array_with_nulls).unwrap();
911        builder.append_array(&input_2_array_with_nulls).unwrap();
912
913        let actual = builder.finish();
914        let expected = GenericStringArray::<i32>::from(vec![
915            Some("hello"),
916            None, // world
917            Some("how"),
918            None, // are
919            None, // you
920            Some("doing"),
921            Some("today"),
922            Some("I"),
923            None, // am
924            None, // doing
925            None, // well
926            Some("thank"),
927            None, // "you",
928            Some("for"),
929            Some("asking"),
930        ]);
931
932        assert_eq!(actual, expected);
933
934        let expected_underlying_buffer = Buffer::from(
935            [
936                "hello", "world", "how", "are", "you", "doing", "today", "I", "am", "doing",
937                "well", "thank", "you", "for", "asking",
938            ]
939            .join("")
940            .as_bytes(),
941        );
942        assert_eq!(actual.values(), &expected_underlying_buffer);
943    }
944
945    #[test]
946    fn append_array_with_continues_indices() {
947        let input = vec![
948            "hello", "world", "how", "are", "you", "doing", "today", "I", "am", "doing", "well",
949            "thank", "you", "for", "asking",
950        ];
951        let full_array = GenericStringArray::<i32>::from(input);
952        let slice1 = full_array.slice(0, 3);
953        let slice2 = full_array.slice(3, 4);
954        let slice3 = full_array.slice(7, full_array.len() - 7);
955
956        let mut builder = GenericStringBuilder::<i32>::new();
957        builder.append_array(&slice1).unwrap();
958        builder.append_array(&slice2).unwrap();
959        builder.append_array(&slice3).unwrap();
960
961        let actual = builder.finish();
962
963        assert_eq!(actual, full_array);
964    }
965
966    #[test]
967    fn test_append_array_offset_overflow_precise() {
968        let mut builder = GenericStringBuilder::<i32>::new();
969
970        let initial_string = "x".repeat(i32::MAX as usize - 100);
971        builder.append_value(&initial_string);
972
973        let overflow_string = "y".repeat(200);
974        let overflow_array = GenericStringArray::<i32>::from(vec![overflow_string.as_str()]);
975
976        let result = builder.append_array(&overflow_array);
977
978        assert!(matches!(result, Err(ArrowError::OffsetOverflowError(_))));
979    }
980
981    #[test]
982    fn test_append_value_n() {
983        let mut builder = GenericStringBuilder::<i32>::new();
984        builder.append_value("hello");
985        builder.append_value_n("world", 3);
986        builder.append_null();
987        let array = builder.finish();
988
989        assert_eq!(5, array.len());
990        assert_eq!(1, array.null_count());
991        assert_eq!("hello", array.value(0));
992        assert_eq!("world", array.value(1));
993        assert_eq!("world", array.value(2));
994        assert_eq!("world", array.value(3));
995        assert!(array.is_null(4));
996    }
997}
arrow_array/builder/generic_bytes_builder.rs

arrow_array/builder/
generic_bytes_builder.rs
