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
3// distributed with this work for additional information
4// regarding copyright ownership.  The ASF licenses this file
5// to you under the Apache License, Version 2.0 (the
6// "License"); you may not use this file except in compliance
7// with the License.  You may obtain a copy of the License at
8//
9//   http://www.apache.org/licenses/LICENSE-2.0
10//
11// Unless required by applicable law or agreed to in writing,
12// software distributed under the License is distributed on an
13// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
14// KIND, either express or implied.  See the License for the
15// specific language governing permissions and limitations
16// under the License.
17
18use crate::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            offsets_builder,
80            value_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    /// Append an `Option` value into the builder.
114    ///
115    /// - A `None` value will append a null value.
116    /// - A `Some` value will append the value.
117    ///
118    /// See [`Self::append_value`] for more panic information.
119    #[inline]
120    pub fn append_option(&mut self, value: Option<impl AsRef<T::Native>>) {
121        match value {
122            None => self.append_null(),
123            Some(v) => self.append_value(v),
124        };
125    }
126
127    /// Append a null value into the builder.
128    #[inline]
129    pub fn append_null(&mut self) {
130        self.null_buffer_builder.append(false);
131        self.offsets_builder.push(self.next_offset());
132    }
133
134    /// Appends `n` `null`s into the builder.
135    #[inline]
136    pub fn append_nulls(&mut self, n: usize) {
137        self.null_buffer_builder.append_n_nulls(n);
138        let next_offset = self.next_offset();
139        self.offsets_builder
140            .extend(std::iter::repeat_n(next_offset, n));
141    }
142
143    /// Appends array values and null to this builder as is
144    /// (this means that underlying null values are copied as is).
145    #[inline]
146    pub fn append_array(&mut self, array: &GenericByteArray<T>) -> Result<(), ArrowError> {
147        use num_traits::CheckedAdd;
148        if array.len() == 0 {
149            return Ok(());
150        }
151
152        let offsets = array.offsets();
153
154        // If the offsets are contiguous, we can append them directly avoiding the need to align
155        // for example, when the first appended array is not sliced (starts at offset 0)
156        if self.next_offset() == offsets[0] {
157            self.offsets_builder.extend_from_slice(&offsets[1..]);
158        } else {
159            // Shifting all the offsets
160            let shift: T::Offset = self.next_offset() - offsets[0];
161
162            if shift.checked_add(&offsets[offsets.len() - 1]).is_none() {
163                return Err(ArrowError::OffsetOverflowError(
164                    shift.as_usize() + offsets[offsets.len() - 1].as_usize(),
165                ));
166            }
167
168            self.offsets_builder
169                .extend(offsets[1..].iter().map(|&offset| offset + shift));
170        }
171
172        // Append underlying values, starting from the first offset and ending at the last offset
173        self.value_builder.extend_from_slice(
174            &array.values().as_slice()[offsets[0].as_usize()..offsets[array.len()].as_usize()],
175        );
176
177        if let Some(null_buffer) = array.nulls() {
178            self.null_buffer_builder.append_buffer(null_buffer);
179        } else {
180            self.null_buffer_builder.append_n_non_nulls(array.len());
181        }
182        Ok(())
183    }
184
185    /// Builds the [`GenericByteArray`] and reset this builder.
186    pub fn finish(&mut self) -> GenericByteArray<T> {
187        let array_type = T::DATA_TYPE;
188        let array_builder = ArrayDataBuilder::new(array_type)
189            .len(self.len())
190            .add_buffer(std::mem::take(&mut self.offsets_builder).into())
191            .add_buffer(std::mem::take(&mut self.value_builder).into())
192            .nulls(self.null_buffer_builder.finish());
193
194        self.offsets_builder.push(self.next_offset());
195        let array_data = unsafe { array_builder.build_unchecked() };
196        GenericByteArray::from(array_data)
197    }
198
199    /// Builds the [`GenericByteArray`] without resetting the builder.
200    pub fn finish_cloned(&self) -> GenericByteArray<T> {
201        let array_type = T::DATA_TYPE;
202        let offset_buffer = Buffer::from_slice_ref(self.offsets_builder.as_slice());
203        let value_buffer = Buffer::from_slice_ref(self.value_builder.as_slice());
204        let array_builder = ArrayDataBuilder::new(array_type)
205            .len(self.len())
206            .add_buffer(offset_buffer)
207            .add_buffer(value_buffer)
208            .nulls(self.null_buffer_builder.finish_cloned());
209
210        let array_data = unsafe { array_builder.build_unchecked() };
211        GenericByteArray::from(array_data)
212    }
213
214    /// Returns the current values buffer as a slice
215    pub fn values_slice(&self) -> &[u8] {
216        self.value_builder.as_slice()
217    }
218
219    /// Returns the current offsets buffer as a slice
220    pub fn offsets_slice(&self) -> &[T::Offset] {
221        self.offsets_builder.as_slice()
222    }
223
224    /// Returns the current null buffer as a slice
225    pub fn validity_slice(&self) -> Option<&[u8]> {
226        self.null_buffer_builder.as_slice()
227    }
228
229    /// Returns the current null buffer as a mutable slice
230    pub fn validity_slice_mut(&mut self) -> Option<&mut [u8]> {
231        self.null_buffer_builder.as_slice_mut()
232    }
233}
234
235impl<T: ByteArrayType> std::fmt::Debug for GenericByteBuilder<T> {
236    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
237        write!(f, "{}{}Builder", T::Offset::PREFIX, T::PREFIX)?;
238        f.debug_struct("")
239            .field("value_builder", &self.value_builder)
240            .field("offsets_builder", &self.offsets_builder)
241            .field("null_buffer_builder", &self.null_buffer_builder)
242            .finish()
243    }
244}
245
246impl<T: ByteArrayType> Default for GenericByteBuilder<T> {
247    fn default() -> Self {
248        Self::new()
249    }
250}
251
252impl<T: ByteArrayType> ArrayBuilder for GenericByteBuilder<T> {
253    /// Returns the number of binary slots in the builder
254    fn len(&self) -> usize {
255        self.null_buffer_builder.len()
256    }
257
258    /// Builds the array and reset this builder.
259    fn finish(&mut self) -> ArrayRef {
260        Arc::new(self.finish())
261    }
262
263    /// Builds the array without resetting the builder.
264    fn finish_cloned(&self) -> ArrayRef {
265        Arc::new(self.finish_cloned())
266    }
267
268    /// Returns the builder as a non-mutable `Any` reference.
269    fn as_any(&self) -> &dyn Any {
270        self
271    }
272
273    /// Returns the builder as a mutable `Any` reference.
274    fn as_any_mut(&mut self) -> &mut dyn Any {
275        self
276    }
277
278    /// Returns the boxed builder as a box of `Any`.
279    fn into_box_any(self: Box<Self>) -> Box<dyn Any> {
280        self
281    }
282}
283
284impl<T: ByteArrayType, V: AsRef<T::Native>> Extend<Option<V>> for GenericByteBuilder<T> {
285    #[inline]
286    fn extend<I: IntoIterator<Item = Option<V>>>(&mut self, iter: I) {
287        for v in iter {
288            self.append_option(v)
289        }
290    }
291}
292
293/// Array builder for [`GenericStringArray`][crate::GenericStringArray]
294///
295/// Values can be appended using [`GenericByteBuilder::append_value`], and nulls with
296/// [`GenericByteBuilder::append_null`].
297///
298/// This builder also implements [`std::fmt::Write`] with any written data
299/// included in the next appended value. This allows using [`std::fmt::Display`]
300/// with standard Rust idioms like `write!` and `writeln!` to write data
301/// directly to the builder without intermediate allocations.
302///
303/// # Example writing strings with `append_value`
304/// ```
305/// # use arrow_array::builder::GenericStringBuilder;
306/// let mut builder = GenericStringBuilder::<i32>::new();
307///
308/// // Write one string value
309/// builder.append_value("foobarbaz");
310///
311/// // Write a second string
312/// builder.append_value("v2");
313///
314/// let array = builder.finish();
315/// assert_eq!(array.value(0), "foobarbaz");
316/// assert_eq!(array.value(1), "v2");
317/// ```
318///
319/// # Example incrementally writing strings with `std::fmt::Write`
320///
321/// ```
322/// # use std::fmt::Write;
323/// # use arrow_array::builder::GenericStringBuilder;
324/// let mut builder = GenericStringBuilder::<i32>::new();
325///
326/// // Write data in multiple `write!` calls
327/// write!(builder, "foo").unwrap();
328/// write!(builder, "bar").unwrap();
329/// // The next call to append_value finishes the current string
330/// // including all previously written strings.
331/// builder.append_value("baz");
332///
333/// // Write second value with a single write call
334/// write!(builder, "v2").unwrap();
335/// // finish the value by calling append_value with an empty string
336/// builder.append_value("");
337///
338/// let array = builder.finish();
339/// assert_eq!(array.value(0), "foobarbaz");
340/// assert_eq!(array.value(1), "v2");
341/// ```
342pub type GenericStringBuilder<O> = GenericByteBuilder<GenericStringType<O>>;
343
344impl<O: OffsetSizeTrait> std::fmt::Write for GenericStringBuilder<O> {
345    fn write_str(&mut self, s: &str) -> std::fmt::Result {
346        self.value_builder.extend_from_slice(s.as_bytes());
347        Ok(())
348    }
349}
350
351///  Array builder for [`GenericBinaryArray`][crate::GenericBinaryArray]
352///
353/// Values can be appended using [`GenericByteBuilder::append_value`], and nulls with
354/// [`GenericByteBuilder::append_null`].
355///
356/// # Example
357/// ```
358/// # use arrow_array::builder::GenericBinaryBuilder;
359/// let mut builder = GenericBinaryBuilder::<i32>::new();
360///
361/// // Write data
362/// builder.append_value("foo");
363///
364/// // Write second value
365/// builder.append_value(&[0,1,2]);
366///
367/// let array = builder.finish();
368/// // binary values
369/// assert_eq!(array.value(0), b"foo");
370/// assert_eq!(array.value(1), b"\x00\x01\x02");
371/// ```
372///
373/// # Example incrementally writing bytes with `write_bytes`
374///
375/// ```
376/// # use std::io::Write;
377/// # use arrow_array::builder::GenericBinaryBuilder;
378/// let mut builder = GenericBinaryBuilder::<i32>::new();
379///
380/// // Write data in multiple `write_bytes` calls
381/// write!(builder, "foo").unwrap();
382/// write!(builder, "bar").unwrap();
383/// // The next call to append_value finishes the current string
384/// // including all previously written strings.
385/// builder.append_value("baz");
386///
387/// // Write second value with a single write call
388/// write!(builder, "v2").unwrap();
389/// // finish the value by calling append_value with an empty string
390/// builder.append_value("");
391///
392/// let array = builder.finish();
393/// assert_eq!(array.value(0), "foobarbaz".as_bytes());
394/// assert_eq!(array.value(1), "v2".as_bytes());
395/// ```
396pub type GenericBinaryBuilder<O> = GenericByteBuilder<GenericBinaryType<O>>;
397
398impl<O: OffsetSizeTrait> std::io::Write for GenericBinaryBuilder<O> {
399    fn write(&mut self, bs: &[u8]) -> std::io::Result<usize> {
400        self.value_builder.extend_from_slice(bs);
401        Ok(bs.len())
402    }
403
404    fn flush(&mut self) -> std::io::Result<()> {
405        Ok(())
406    }
407}
408
409#[cfg(test)]
410mod tests {
411    use super::*;
412    use crate::GenericStringArray;
413    use crate::array::Array;
414    use arrow_buffer::NullBuffer;
415    use std::fmt::Write as _;
416    use std::io::Write as _;
417
418    fn _test_generic_binary_builder<O: OffsetSizeTrait>() {
419        let mut builder = GenericBinaryBuilder::<O>::new();
420
421        builder.append_value(b"hello");
422        builder.append_value(b"");
423        builder.append_null();
424        builder.append_value(b"rust");
425
426        let array = builder.finish();
427
428        assert_eq!(4, array.len());
429        assert_eq!(1, array.null_count());
430        assert_eq!(b"hello", array.value(0));
431        assert_eq!([] as [u8; 0], array.value(1));
432        assert!(array.is_null(2));
433        assert_eq!(b"rust", array.value(3));
434        assert_eq!(O::from_usize(5).unwrap(), array.value_offsets()[2]);
435        assert_eq!(O::from_usize(4).unwrap(), array.value_length(3));
436    }
437
438    #[test]
439    fn test_binary_builder() {
440        _test_generic_binary_builder::<i32>()
441    }
442
443    #[test]
444    fn test_large_binary_builder() {
445        _test_generic_binary_builder::<i64>()
446    }
447
448    fn _test_generic_binary_builder_all_nulls<O: OffsetSizeTrait>() {
449        let mut builder = GenericBinaryBuilder::<O>::new();
450        builder.append_null();
451        builder.append_null();
452        builder.append_null();
453        builder.append_nulls(2);
454        assert_eq!(5, builder.len());
455        assert!(!builder.is_empty());
456
457        let array = builder.finish();
458        assert_eq!(5, array.null_count());
459        assert_eq!(5, array.len());
460        assert!(array.is_null(0));
461        assert!(array.is_null(1));
462        assert!(array.is_null(2));
463        assert!(array.is_null(3));
464        assert!(array.is_null(4));
465    }
466
467    #[test]
468    fn test_binary_builder_all_nulls() {
469        _test_generic_binary_builder_all_nulls::<i32>()
470    }
471
472    #[test]
473    fn test_large_binary_builder_all_nulls() {
474        _test_generic_binary_builder_all_nulls::<i64>()
475    }
476
477    fn _test_generic_binary_builder_reset<O: OffsetSizeTrait>() {
478        let mut builder = GenericBinaryBuilder::<O>::new();
479
480        builder.append_value(b"hello");
481        builder.append_value(b"");
482        builder.append_null();
483        builder.append_value(b"rust");
484        builder.finish();
485
486        assert!(builder.is_empty());
487
488        builder.append_value(b"parquet");
489        builder.append_null();
490        builder.append_value(b"arrow");
491        builder.append_value(b"");
492        builder.append_nulls(2);
493        builder.append_value(b"hi");
494        let array = builder.finish();
495
496        assert_eq!(7, array.len());
497        assert_eq!(3, array.null_count());
498        assert_eq!(b"parquet", array.value(0));
499        assert!(array.is_null(1));
500        assert!(array.is_null(4));
501        assert!(array.is_null(5));
502        assert_eq!(b"arrow", array.value(2));
503        assert_eq!(b"", array.value(1));
504        assert_eq!(b"hi", array.value(6));
505
506        assert_eq!(O::zero(), array.value_offsets()[0]);
507        assert_eq!(O::from_usize(7).unwrap(), array.value_offsets()[2]);
508        assert_eq!(O::from_usize(14).unwrap(), array.value_offsets()[7]);
509        assert_eq!(O::from_usize(5).unwrap(), array.value_length(2));
510    }
511
512    #[test]
513    fn test_binary_builder_reset() {
514        _test_generic_binary_builder_reset::<i32>()
515    }
516
517    #[test]
518    fn test_large_binary_builder_reset() {
519        _test_generic_binary_builder_reset::<i64>()
520    }
521
522    fn _test_generic_string_array_builder<O: OffsetSizeTrait>() {
523        let mut builder = GenericStringBuilder::<O>::new();
524        let owned = "arrow".to_owned();
525
526        builder.append_value("hello");
527        builder.append_value("");
528        builder.append_value(&owned);
529        builder.append_null();
530        builder.append_option(Some("rust"));
531        builder.append_option(None::<&str>);
532        builder.append_option(None::<String>);
533        builder.append_nulls(2);
534        builder.append_value("parquet");
535        assert_eq!(10, builder.len());
536
537        assert_eq!(
538            GenericStringArray::<O>::from(vec![
539                Some("hello"),
540                Some(""),
541                Some("arrow"),
542                None,
543                Some("rust"),
544                None,
545                None,
546                None,
547                None,
548                Some("parquet")
549            ]),
550            builder.finish()
551        );
552    }
553
554    #[test]
555    fn test_string_array_builder() {
556        _test_generic_string_array_builder::<i32>()
557    }
558
559    #[test]
560    fn test_large_string_array_builder() {
561        _test_generic_string_array_builder::<i64>()
562    }
563
564    fn _test_generic_string_array_builder_finish<O: OffsetSizeTrait>() {
565        let mut builder = GenericStringBuilder::<O>::with_capacity(3, 11);
566
567        builder.append_value("hello");
568        builder.append_value("rust");
569        builder.append_null();
570
571        builder.finish();
572        assert!(builder.is_empty());
573        assert_eq!(&[O::zero()], builder.offsets_slice());
574
575        builder.append_value("arrow");
576        builder.append_value("parquet");
577        let arr = builder.finish();
578        // array should not have null buffer because there is not `null` value.
579        assert!(arr.nulls().is_none());
580        assert_eq!(GenericStringArray::<O>::from(vec!["arrow", "parquet"]), arr,)
581    }
582
583    #[test]
584    fn test_string_array_builder_finish() {
585        _test_generic_string_array_builder_finish::<i32>()
586    }
587
588    #[test]
589    fn test_large_string_array_builder_finish() {
590        _test_generic_string_array_builder_finish::<i64>()
591    }
592
593    fn _test_generic_string_array_builder_finish_cloned<O: OffsetSizeTrait>() {
594        let mut builder = GenericStringBuilder::<O>::with_capacity(3, 11);
595
596        builder.append_value("hello");
597        builder.append_value("rust");
598        builder.append_null();
599
600        let mut arr = builder.finish_cloned();
601        assert!(!builder.is_empty());
602        assert_eq!(3, arr.len());
603
604        builder.append_value("arrow");
605        builder.append_value("parquet");
606        arr = builder.finish();
607
608        assert!(arr.nulls().is_some());
609        assert_eq!(&[O::zero()], builder.offsets_slice());
610        assert_eq!(5, arr.len());
611    }
612
613    #[test]
614    fn test_string_array_builder_finish_cloned() {
615        _test_generic_string_array_builder_finish_cloned::<i32>()
616    }
617
618    #[test]
619    fn test_large_string_array_builder_finish_cloned() {
620        _test_generic_string_array_builder_finish_cloned::<i64>()
621    }
622
623    #[test]
624    fn test_extend() {
625        let mut builder = GenericStringBuilder::<i32>::new();
626        builder.extend(["a", "b", "c", "", "a", "b", "c"].into_iter().map(Some));
627        builder.extend(["d", "cupcakes", "hello"].into_iter().map(Some));
628        let array = builder.finish();
629        assert_eq!(array.value_offsets(), &[0, 1, 2, 3, 3, 4, 5, 6, 7, 15, 20]);
630        assert_eq!(array.value_data(), b"abcabcdcupcakeshello");
631    }
632
633    #[test]
634    fn test_write_str() {
635        let mut builder = GenericStringBuilder::<i32>::new();
636        write!(builder, "foo").unwrap();
637        builder.append_value("");
638        writeln!(builder, "bar").unwrap();
639        builder.append_value("");
640        write!(builder, "fiz").unwrap();
641        write!(builder, "buz").unwrap();
642        builder.append_value("");
643        let a = builder.finish();
644        let r: Vec<_> = a.iter().flatten().collect();
645        assert_eq!(r, &["foo", "bar\n", "fizbuz"])
646    }
647
648    #[test]
649    fn test_write_bytes() {
650        let mut builder = GenericBinaryBuilder::<i32>::new();
651        write!(builder, "foo").unwrap();
652        builder.append_value("");
653        writeln!(builder, "bar").unwrap();
654        builder.append_value("");
655        write!(builder, "fiz").unwrap();
656        write!(builder, "buz").unwrap();
657        builder.append_value("");
658        let a = builder.finish();
659        let r: Vec<_> = a.iter().flatten().collect();
660        assert_eq!(
661            r,
662            &["foo".as_bytes(), "bar\n".as_bytes(), "fizbuz".as_bytes()]
663        )
664    }
665
666    #[test]
667    fn test_append_array_without_nulls() {
668        let input = vec![
669            "hello", "world", "how", "are", "you", "doing", "today", "I", "am", "doing", "well",
670            "thank", "you", "for", "asking",
671        ];
672        let arr1 = GenericStringArray::<i32>::from(input[..3].to_vec());
673        let arr2 = GenericStringArray::<i32>::from(input[3..7].to_vec());
674        let arr3 = GenericStringArray::<i32>::from(input[7..].to_vec());
675
676        let mut builder = GenericStringBuilder::<i32>::new();
677        builder.append_array(&arr1).unwrap();
678        builder.append_array(&arr2).unwrap();
679        builder.append_array(&arr3).unwrap();
680
681        let actual = builder.finish();
682        let expected = GenericStringArray::<i32>::from(input);
683
684        assert_eq!(actual, expected);
685    }
686
687    #[test]
688    fn test_append_array_with_nulls() {
689        let input = vec![
690            Some("hello"),
691            None,
692            Some("how"),
693            None,
694            None,
695            None,
696            None,
697            Some("I"),
698            Some("am"),
699            Some("doing"),
700            Some("well"),
701        ];
702        let arr1 = GenericStringArray::<i32>::from(input[..3].to_vec());
703        let arr2 = GenericStringArray::<i32>::from(input[3..7].to_vec());
704        let arr3 = GenericStringArray::<i32>::from(input[7..].to_vec());
705
706        let mut builder = GenericStringBuilder::<i32>::new();
707        builder.append_array(&arr1).unwrap();
708        builder.append_array(&arr2).unwrap();
709        builder.append_array(&arr3).unwrap();
710
711        let actual = builder.finish();
712        let expected = GenericStringArray::<i32>::from(input);
713
714        assert_eq!(actual, expected);
715    }
716
717    #[test]
718    fn test_append_empty_array() {
719        let arr = GenericStringArray::<i32>::from(Vec::<&str>::new());
720        let mut builder = GenericStringBuilder::<i32>::new();
721        builder.append_array(&arr).unwrap();
722        let result = builder.finish();
723        assert_eq!(result.len(), 0);
724    }
725
726    #[test]
727    fn test_append_array_with_offset_not_starting_at_0() {
728        let input = vec![
729            Some("hello"),
730            None,
731            Some("how"),
732            None,
733            None,
734            None,
735            None,
736            Some("I"),
737            Some("am"),
738            Some("doing"),
739            Some("well"),
740        ];
741        let full_array = GenericStringArray::<i32>::from(input);
742        let sliced = full_array.slice(1, 4);
743
744        assert_ne!(sliced.offsets()[0].as_usize(), 0);
745        assert_ne!(sliced.offsets().last(), full_array.offsets().last());
746
747        let mut builder = GenericStringBuilder::<i32>::new();
748        builder.append_array(&sliced).unwrap();
749        let actual = builder.finish();
750
751        let expected = GenericStringArray::<i32>::from(vec![None, Some("how"), None, None]);
752
753        assert_eq!(actual, expected);
754    }
755
756    #[test]
757    fn test_append_underlying_null_values_added_as_is() {
758        let input_1_array_with_nulls = {
759            let input = vec![
760                "hello", "world", "how", "are", "you", "doing", "today", "I", "am",
761            ];
762            let (offsets, buffer, _) = GenericStringArray::<i32>::from(input).into_parts();
763
764            GenericStringArray::<i32>::new(
765                offsets,
766                buffer,
767                Some(NullBuffer::from(&[
768                    true, false, true, false, false, true, true, true, false,
769                ])),
770            )
771        };
772        let input_2_array_with_nulls = {
773            let input = vec!["doing", "well", "thank", "you", "for", "asking"];
774            let (offsets, buffer, _) = GenericStringArray::<i32>::from(input).into_parts();
775
776            GenericStringArray::<i32>::new(
777                offsets,
778                buffer,
779                Some(NullBuffer::from(&[false, false, true, false, true, true])),
780            )
781        };
782
783        let mut builder = GenericStringBuilder::<i32>::new();
784        builder.append_array(&input_1_array_with_nulls).unwrap();
785        builder.append_array(&input_2_array_with_nulls).unwrap();
786
787        let actual = builder.finish();
788        let expected = GenericStringArray::<i32>::from(vec![
789            Some("hello"),
790            None, // world
791            Some("how"),
792            None, // are
793            None, // you
794            Some("doing"),
795            Some("today"),
796            Some("I"),
797            None, // am
798            None, // doing
799            None, // well
800            Some("thank"),
801            None, // "you",
802            Some("for"),
803            Some("asking"),
804        ]);
805
806        assert_eq!(actual, expected);
807
808        let expected_underlying_buffer = Buffer::from(
809            [
810                "hello", "world", "how", "are", "you", "doing", "today", "I", "am", "doing",
811                "well", "thank", "you", "for", "asking",
812            ]
813            .join("")
814            .as_bytes(),
815        );
816        assert_eq!(actual.values(), &expected_underlying_buffer);
817    }
818
819    #[test]
820    fn append_array_with_continues_indices() {
821        let input = vec![
822            "hello", "world", "how", "are", "you", "doing", "today", "I", "am", "doing", "well",
823            "thank", "you", "for", "asking",
824        ];
825        let full_array = GenericStringArray::<i32>::from(input);
826        let slice1 = full_array.slice(0, 3);
827        let slice2 = full_array.slice(3, 4);
828        let slice3 = full_array.slice(7, full_array.len() - 7);
829
830        let mut builder = GenericStringBuilder::<i32>::new();
831        builder.append_array(&slice1).unwrap();
832        builder.append_array(&slice2).unwrap();
833        builder.append_array(&slice3).unwrap();
834
835        let actual = builder.finish();
836
837        assert_eq!(actual, full_array);
838    }
839
840    #[test]
841    fn test_append_array_offset_overflow_precise() {
842        let mut builder = GenericStringBuilder::<i32>::new();
843
844        let initial_string = "x".repeat(i32::MAX as usize - 100);
845        builder.append_value(&initial_string);
846
847        let overflow_string = "y".repeat(200);
848        let overflow_array = GenericStringArray::<i32>::from(vec![overflow_string.as_str()]);
849
850        let result = builder.append_array(&overflow_array);
851
852        assert!(matches!(result, Err(ArrowError::OffsetOverflowError(_))));
853    }
854}
arrow_array/builder/generic_bytes_builder.rs

arrow_array/builder/
generic_bytes_builder.rs
