arrow_array/array/
byte_array.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::array::{get_offsets, print_long_array};
19use crate::builder::GenericByteBuilder;
20use crate::iterator::ArrayIter;
21use crate::types::bytes::ByteArrayNativeType;
22use crate::types::ByteArrayType;
23use crate::{Array, ArrayAccessor, ArrayRef, OffsetSizeTrait, Scalar};
24use arrow_buffer::{ArrowNativeType, Buffer, MutableBuffer};
25use arrow_buffer::{NullBuffer, OffsetBuffer};
26use arrow_data::{ArrayData, ArrayDataBuilder};
27use arrow_schema::{ArrowError, DataType};
28use std::any::Any;
29use std::sync::Arc;
30
31/// An array of [variable length byte arrays](https://arrow.apache.org/docs/format/Columnar.html#variable-size-binary-layout)
32///
33/// See [`StringArray`] and [`LargeStringArray`] for storing utf8 encoded string data
34///
35/// See [`BinaryArray`] and [`LargeBinaryArray`] for storing arbitrary bytes
36///
37/// # Example: From a Vec
38///
39/// ```
40/// # use arrow_array::{Array, GenericByteArray, types::Utf8Type};
41/// let arr: GenericByteArray<Utf8Type> = vec!["hello", "world", ""].into();
42/// assert_eq!(arr.value_data(), b"helloworld");
43/// assert_eq!(arr.value_offsets(), &[0, 5, 10, 10]);
44/// let values: Vec<_> = arr.iter().collect();
45/// assert_eq!(values, &[Some("hello"), Some("world"), Some("")]);
46/// ```
47///
48/// # Example: From an optional Vec
49///
50/// ```
51/// # use arrow_array::{Array, GenericByteArray, types::Utf8Type};
52/// let arr: GenericByteArray<Utf8Type> = vec![Some("hello"), Some("world"), Some(""), None].into();
53/// assert_eq!(arr.value_data(), b"helloworld");
54/// assert_eq!(arr.value_offsets(), &[0, 5, 10, 10, 10]);
55/// let values: Vec<_> = arr.iter().collect();
56/// assert_eq!(values, &[Some("hello"), Some("world"), Some(""), None]);
57/// ```
58///
59/// # Example: From an iterator of option
60///
61/// ```
62/// # use arrow_array::{Array, GenericByteArray, types::Utf8Type};
63/// let arr: GenericByteArray<Utf8Type> = (0..5).map(|x| (x % 2 == 0).then(|| x.to_string())).collect();
64/// let values: Vec<_> = arr.iter().collect();
65/// assert_eq!(values, &[Some("0"), None, Some("2"), None, Some("4")]);
66/// ```
67///
68/// # Example: Using Builder
69///
70/// ```
71/// # use arrow_array::Array;
72/// # use arrow_array::builder::GenericByteBuilder;
73/// # use arrow_array::types::Utf8Type;
74/// let mut builder = GenericByteBuilder::<Utf8Type>::new();
75/// builder.append_value("hello");
76/// builder.append_null();
77/// builder.append_value("world");
78/// let array = builder.finish();
79/// let values: Vec<_> = array.iter().collect();
80/// assert_eq!(values, &[Some("hello"), None, Some("world")]);
81/// ```
82///
83/// [`StringArray`]: crate::StringArray
84/// [`LargeStringArray`]: crate::LargeStringArray
85/// [`BinaryArray`]: crate::BinaryArray
86/// [`LargeBinaryArray`]: crate::LargeBinaryArray
87pub struct GenericByteArray<T: ByteArrayType> {
88    data_type: DataType,
89    value_offsets: OffsetBuffer<T::Offset>,
90    value_data: Buffer,
91    nulls: Option<NullBuffer>,
92}
93
94impl<T: ByteArrayType> Clone for GenericByteArray<T> {
95    fn clone(&self) -> Self {
96        Self {
97            data_type: T::DATA_TYPE,
98            value_offsets: self.value_offsets.clone(),
99            value_data: self.value_data.clone(),
100            nulls: self.nulls.clone(),
101        }
102    }
103}
104
105impl<T: ByteArrayType> GenericByteArray<T> {
106    /// Data type of the array.
107    pub const DATA_TYPE: DataType = T::DATA_TYPE;
108
109    /// Create a new [`GenericByteArray`] from the provided parts, panicking on failure
110    ///
111    /// # Panics
112    ///
113    /// Panics if [`GenericByteArray::try_new`] returns an error
114    pub fn new(
115        offsets: OffsetBuffer<T::Offset>,
116        values: Buffer,
117        nulls: Option<NullBuffer>,
118    ) -> Self {
119        Self::try_new(offsets, values, nulls).unwrap()
120    }
121
122    /// Create a new [`GenericByteArray`] from the provided parts, returning an error on failure
123    ///
124    /// # Errors
125    ///
126    /// * `offsets.len() - 1 != nulls.len()`
127    /// * Any consecutive pair of `offsets` does not denote a valid slice of `values`
128    pub fn try_new(
129        offsets: OffsetBuffer<T::Offset>,
130        values: Buffer,
131        nulls: Option<NullBuffer>,
132    ) -> Result<Self, ArrowError> {
133        let len = offsets.len() - 1;
134
135        // Verify that each pair of offsets is a valid slices of values
136        T::validate(&offsets, &values)?;
137
138        if let Some(n) = nulls.as_ref() {
139            if n.len() != len {
140                return Err(ArrowError::InvalidArgumentError(format!(
141                    "Incorrect length of null buffer for {}{}Array, expected {len} got {}",
142                    T::Offset::PREFIX,
143                    T::PREFIX,
144                    n.len(),
145                )));
146            }
147        }
148
149        Ok(Self {
150            data_type: T::DATA_TYPE,
151            value_offsets: offsets,
152            value_data: values,
153            nulls,
154        })
155    }
156
157    /// Create a new [`GenericByteArray`] from the provided parts, without validation
158    ///
159    /// # Safety
160    ///
161    /// Safe if [`Self::try_new`] would not error
162    pub unsafe fn new_unchecked(
163        offsets: OffsetBuffer<T::Offset>,
164        values: Buffer,
165        nulls: Option<NullBuffer>,
166    ) -> Self {
167        if cfg!(feature = "force_validate") {
168            return Self::new(offsets, values, nulls);
169        }
170        Self {
171            data_type: T::DATA_TYPE,
172            value_offsets: offsets,
173            value_data: values,
174            nulls,
175        }
176    }
177
178    /// Create a new [`GenericByteArray`] of length `len` where all values are null
179    pub fn new_null(len: usize) -> Self {
180        Self {
181            data_type: T::DATA_TYPE,
182            value_offsets: OffsetBuffer::new_zeroed(len),
183            value_data: MutableBuffer::new(0).into(),
184            nulls: Some(NullBuffer::new_null(len)),
185        }
186    }
187
188    /// Create a new [`Scalar`] from `v`
189    pub fn new_scalar(value: impl AsRef<T::Native>) -> Scalar<Self> {
190        Scalar::new(Self::from_iter_values(std::iter::once(value)))
191    }
192
193    /// Creates a [`GenericByteArray`] based on an iterator of values without nulls
194    pub fn from_iter_values<Ptr, I>(iter: I) -> Self
195    where
196        Ptr: AsRef<T::Native>,
197        I: IntoIterator<Item = Ptr>,
198    {
199        let iter = iter.into_iter();
200        let (_, data_len) = iter.size_hint();
201        let data_len = data_len.expect("Iterator must be sized"); // panic if no upper bound.
202
203        let mut offsets = MutableBuffer::new((data_len + 1) * std::mem::size_of::<T::Offset>());
204        offsets.push(T::Offset::usize_as(0));
205
206        let mut values = MutableBuffer::new(0);
207        for s in iter {
208            let s: &[u8] = s.as_ref().as_ref();
209            values.extend_from_slice(s);
210            offsets.push(T::Offset::usize_as(values.len()));
211        }
212
213        T::Offset::from_usize(values.len()).expect("offset overflow");
214        let offsets = Buffer::from(offsets);
215
216        // Safety: valid by construction
217        let value_offsets = unsafe { OffsetBuffer::new_unchecked(offsets.into()) };
218
219        Self {
220            data_type: T::DATA_TYPE,
221            value_data: values.into(),
222            value_offsets,
223            nulls: None,
224        }
225    }
226
227    /// Deconstruct this array into its constituent parts
228    pub fn into_parts(self) -> (OffsetBuffer<T::Offset>, Buffer, Option<NullBuffer>) {
229        (self.value_offsets, self.value_data, self.nulls)
230    }
231
232    /// Returns the length for value at index `i`.
233    /// # Panics
234    /// Panics if index `i` is out of bounds.
235    #[inline]
236    pub fn value_length(&self, i: usize) -> T::Offset {
237        let offsets = self.value_offsets();
238        offsets[i + 1] - offsets[i]
239    }
240
241    /// Returns a reference to the offsets of this array
242    ///
243    /// Unlike [`Self::value_offsets`] this returns the [`OffsetBuffer`]
244    /// allowing for zero-copy cloning
245    #[inline]
246    pub fn offsets(&self) -> &OffsetBuffer<T::Offset> {
247        &self.value_offsets
248    }
249
250    /// Returns the values of this array
251    ///
252    /// Unlike [`Self::value_data`] this returns the [`Buffer`]
253    /// allowing for zero-copy cloning
254    #[inline]
255    pub fn values(&self) -> &Buffer {
256        &self.value_data
257    }
258
259    /// Returns the raw value data
260    pub fn value_data(&self) -> &[u8] {
261        self.value_data.as_slice()
262    }
263
264    /// Returns true if all data within this array is ASCII
265    pub fn is_ascii(&self) -> bool {
266        let offsets = self.value_offsets();
267        let start = offsets.first().unwrap();
268        let end = offsets.last().unwrap();
269        self.value_data()[start.as_usize()..end.as_usize()].is_ascii()
270    }
271
272    /// Returns the offset values in the offsets buffer
273    #[inline]
274    pub fn value_offsets(&self) -> &[T::Offset] {
275        &self.value_offsets
276    }
277
278    /// Returns the element at index `i`
279    ///
280    /// Note: This method does not check for nulls and the value is arbitrary
281    /// if [`is_null`](Self::is_null) returns true for the index.
282    ///
283    /// # Safety
284    /// Caller is responsible for ensuring that the index is within the bounds of the array
285    pub unsafe fn value_unchecked(&self, i: usize) -> &T::Native {
286        let end = *self.value_offsets().get_unchecked(i + 1);
287        let start = *self.value_offsets().get_unchecked(i);
288
289        // Soundness
290        // pointer alignment & location is ensured by RawPtrBox
291        // buffer bounds/offset is ensured by the value_offset invariants
292
293        // Safety of `to_isize().unwrap()`
294        // `start` and `end` are &OffsetSize, which is a generic type that implements the
295        // OffsetSizeTrait. Currently, only i32 and i64 implement OffsetSizeTrait,
296        // both of which should cleanly cast to isize on an architecture that supports
297        // 32/64-bit offsets
298        let b = std::slice::from_raw_parts(
299            self.value_data
300                .as_ptr()
301                .offset(start.to_isize().unwrap_unchecked()),
302            (end - start).to_usize().unwrap_unchecked(),
303        );
304
305        // SAFETY:
306        // ArrayData is valid
307        T::Native::from_bytes_unchecked(b)
308    }
309
310    /// Returns the element at index `i`
311    ///
312    /// Note: This method does not check for nulls and the value is arbitrary
313    /// (but still well-defined) if [`is_null`](Self::is_null) returns true for the index.
314    ///
315    /// # Panics
316    /// Panics if index `i` is out of bounds.
317    pub fn value(&self, i: usize) -> &T::Native {
318        assert!(
319            i < self.len(),
320            "Trying to access an element at index {} from a {}{}Array of length {}",
321            i,
322            T::Offset::PREFIX,
323            T::PREFIX,
324            self.len()
325        );
326        // SAFETY:
327        // Verified length above
328        unsafe { self.value_unchecked(i) }
329    }
330
331    /// constructs a new iterator
332    pub fn iter(&self) -> ArrayIter<&Self> {
333        ArrayIter::new(self)
334    }
335
336    /// Returns a zero-copy slice of this array with the indicated offset and length.
337    pub fn slice(&self, offset: usize, length: usize) -> Self {
338        Self {
339            data_type: T::DATA_TYPE,
340            value_offsets: self.value_offsets.slice(offset, length),
341            value_data: self.value_data.clone(),
342            nulls: self.nulls.as_ref().map(|n| n.slice(offset, length)),
343        }
344    }
345
346    /// Returns `GenericByteBuilder` of this byte array for mutating its values if the underlying
347    /// offset and data buffers are not shared by others.
348    pub fn into_builder(self) -> Result<GenericByteBuilder<T>, Self> {
349        let len = self.len();
350        let value_len = T::Offset::as_usize(self.value_offsets()[len] - self.value_offsets()[0]);
351
352        let data = self.into_data();
353        let null_bit_buffer = data.nulls().map(|b| b.inner().sliced());
354
355        let element_len = std::mem::size_of::<T::Offset>();
356        let offset_buffer = data.buffers()[0]
357            .slice_with_length(data.offset() * element_len, (len + 1) * element_len);
358
359        let element_len = std::mem::size_of::<u8>();
360        let value_buffer = data.buffers()[1]
361            .slice_with_length(data.offset() * element_len, value_len * element_len);
362
363        drop(data);
364
365        let try_mutable_null_buffer = match null_bit_buffer {
366            None => Ok(None),
367            Some(null_buffer) => {
368                // Null buffer exists, tries to make it mutable
369                null_buffer.into_mutable().map(Some)
370            }
371        };
372
373        let try_mutable_buffers = match try_mutable_null_buffer {
374            Ok(mutable_null_buffer) => {
375                // Got mutable null buffer, tries to get mutable value buffer
376                let try_mutable_offset_buffer = offset_buffer.into_mutable();
377                let try_mutable_value_buffer = value_buffer.into_mutable();
378
379                // try_mutable_offset_buffer.map(...).map_err(...) doesn't work as the compiler complains
380                // mutable_null_buffer is moved into map closure.
381                match (try_mutable_offset_buffer, try_mutable_value_buffer) {
382                    (Ok(mutable_offset_buffer), Ok(mutable_value_buffer)) => unsafe {
383                        Ok(GenericByteBuilder::<T>::new_from_buffer(
384                            mutable_offset_buffer,
385                            mutable_value_buffer,
386                            mutable_null_buffer,
387                        ))
388                    },
389                    (Ok(mutable_offset_buffer), Err(value_buffer)) => Err((
390                        mutable_offset_buffer.into(),
391                        value_buffer,
392                        mutable_null_buffer.map(|b| b.into()),
393                    )),
394                    (Err(offset_buffer), Ok(mutable_value_buffer)) => Err((
395                        offset_buffer,
396                        mutable_value_buffer.into(),
397                        mutable_null_buffer.map(|b| b.into()),
398                    )),
399                    (Err(offset_buffer), Err(value_buffer)) => Err((
400                        offset_buffer,
401                        value_buffer,
402                        mutable_null_buffer.map(|b| b.into()),
403                    )),
404                }
405            }
406            Err(mutable_null_buffer) => {
407                // Unable to get mutable null buffer
408                Err((offset_buffer, value_buffer, Some(mutable_null_buffer)))
409            }
410        };
411
412        match try_mutable_buffers {
413            Ok(builder) => Ok(builder),
414            Err((offset_buffer, value_buffer, null_bit_buffer)) => {
415                let builder = ArrayData::builder(T::DATA_TYPE)
416                    .len(len)
417                    .add_buffer(offset_buffer)
418                    .add_buffer(value_buffer)
419                    .null_bit_buffer(null_bit_buffer);
420
421                let array_data = unsafe { builder.build_unchecked() };
422                let array = GenericByteArray::<T>::from(array_data);
423
424                Err(array)
425            }
426        }
427    }
428}
429
430impl<T: ByteArrayType> std::fmt::Debug for GenericByteArray<T> {
431    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
432        write!(f, "{}{}Array\n[\n", T::Offset::PREFIX, T::PREFIX)?;
433        print_long_array(self, f, |array, index, f| {
434            std::fmt::Debug::fmt(&array.value(index), f)
435        })?;
436        write!(f, "]")
437    }
438}
439
440impl<T: ByteArrayType> Array for GenericByteArray<T> {
441    fn as_any(&self) -> &dyn Any {
442        self
443    }
444
445    fn to_data(&self) -> ArrayData {
446        self.clone().into()
447    }
448
449    fn into_data(self) -> ArrayData {
450        self.into()
451    }
452
453    fn data_type(&self) -> &DataType {
454        &self.data_type
455    }
456
457    fn slice(&self, offset: usize, length: usize) -> ArrayRef {
458        Arc::new(self.slice(offset, length))
459    }
460
461    fn len(&self) -> usize {
462        self.value_offsets.len() - 1
463    }
464
465    fn is_empty(&self) -> bool {
466        self.value_offsets.len() <= 1
467    }
468
469    fn shrink_to_fit(&mut self) {
470        self.value_offsets.shrink_to_fit();
471        self.value_data.shrink_to_fit();
472        if let Some(nulls) = &mut self.nulls {
473            nulls.shrink_to_fit();
474        }
475    }
476
477    fn offset(&self) -> usize {
478        0
479    }
480
481    fn nulls(&self) -> Option<&NullBuffer> {
482        self.nulls.as_ref()
483    }
484
485    fn logical_null_count(&self) -> usize {
486        // More efficient that the default implementation
487        self.null_count()
488    }
489
490    fn get_buffer_memory_size(&self) -> usize {
491        let mut sum = self.value_offsets.inner().inner().capacity();
492        sum += self.value_data.capacity();
493        if let Some(x) = &self.nulls {
494            sum += x.buffer().capacity()
495        }
496        sum
497    }
498
499    fn get_array_memory_size(&self) -> usize {
500        std::mem::size_of::<Self>() + self.get_buffer_memory_size()
501    }
502}
503
504impl<'a, T: ByteArrayType> ArrayAccessor for &'a GenericByteArray<T> {
505    type Item = &'a T::Native;
506
507    fn value(&self, index: usize) -> Self::Item {
508        GenericByteArray::value(self, index)
509    }
510
511    unsafe fn value_unchecked(&self, index: usize) -> Self::Item {
512        GenericByteArray::value_unchecked(self, index)
513    }
514}
515
516impl<T: ByteArrayType> From<ArrayData> for GenericByteArray<T> {
517    fn from(data: ArrayData) -> Self {
518        assert_eq!(
519            data.data_type(),
520            &Self::DATA_TYPE,
521            "{}{}Array expects DataType::{}",
522            T::Offset::PREFIX,
523            T::PREFIX,
524            Self::DATA_TYPE
525        );
526        assert_eq!(
527            data.buffers().len(),
528            2,
529            "{}{}Array data should contain 2 buffers only (offsets and values)",
530            T::Offset::PREFIX,
531            T::PREFIX,
532        );
533        // SAFETY:
534        // ArrayData is valid, and verified type above
535        let value_offsets = unsafe { get_offsets(&data) };
536        let value_data = data.buffers()[1].clone();
537        Self {
538            value_offsets,
539            value_data,
540            data_type: T::DATA_TYPE,
541            nulls: data.nulls().cloned(),
542        }
543    }
544}
545
546impl<T: ByteArrayType> From<GenericByteArray<T>> for ArrayData {
547    fn from(array: GenericByteArray<T>) -> Self {
548        let len = array.len();
549
550        let offsets = array.value_offsets.into_inner().into_inner();
551        let builder = ArrayDataBuilder::new(array.data_type)
552            .len(len)
553            .buffers(vec![offsets, array.value_data])
554            .nulls(array.nulls);
555
556        unsafe { builder.build_unchecked() }
557    }
558}
559
560impl<'a, T: ByteArrayType> IntoIterator for &'a GenericByteArray<T> {
561    type Item = Option<&'a T::Native>;
562    type IntoIter = ArrayIter<Self>;
563
564    fn into_iter(self) -> Self::IntoIter {
565        ArrayIter::new(self)
566    }
567}
568
569impl<'a, Ptr, T: ByteArrayType> FromIterator<&'a Option<Ptr>> for GenericByteArray<T>
570where
571    Ptr: AsRef<T::Native> + 'a,
572{
573    fn from_iter<I: IntoIterator<Item = &'a Option<Ptr>>>(iter: I) -> Self {
574        iter.into_iter()
575            .map(|o| o.as_ref().map(|p| p.as_ref()))
576            .collect()
577    }
578}
579
580impl<Ptr, T: ByteArrayType> FromIterator<Option<Ptr>> for GenericByteArray<T>
581where
582    Ptr: AsRef<T::Native>,
583{
584    fn from_iter<I: IntoIterator<Item = Option<Ptr>>>(iter: I) -> Self {
585        let iter = iter.into_iter();
586        let mut builder = GenericByteBuilder::with_capacity(iter.size_hint().0, 1024);
587        builder.extend(iter);
588        builder.finish()
589    }
590}
591
592#[cfg(test)]
593mod tests {
594    use crate::{BinaryArray, StringArray};
595    use arrow_buffer::{Buffer, NullBuffer, OffsetBuffer};
596
597    #[test]
598    fn try_new() {
599        let data = Buffer::from_slice_ref("helloworld");
600        let offsets = OffsetBuffer::new(vec![0, 5, 10].into());
601        StringArray::new(offsets.clone(), data.clone(), None);
602
603        let nulls = NullBuffer::new_null(3);
604        let err =
605            StringArray::try_new(offsets.clone(), data.clone(), Some(nulls.clone())).unwrap_err();
606        assert_eq!(err.to_string(), "Invalid argument error: Incorrect length of null buffer for StringArray, expected 2 got 3");
607
608        let err = BinaryArray::try_new(offsets.clone(), data.clone(), Some(nulls)).unwrap_err();
609        assert_eq!(err.to_string(), "Invalid argument error: Incorrect length of null buffer for BinaryArray, expected 2 got 3");
610
611        let non_utf8_data = Buffer::from_slice_ref(b"he\xFFloworld");
612        let err = StringArray::try_new(offsets.clone(), non_utf8_data.clone(), None).unwrap_err();
613        assert_eq!(err.to_string(), "Invalid argument error: Encountered non UTF-8 data: invalid utf-8 sequence of 1 bytes from index 2");
614
615        BinaryArray::new(offsets, non_utf8_data, None);
616
617        let offsets = OffsetBuffer::new(vec![0, 5, 11].into());
618        let err = StringArray::try_new(offsets.clone(), data.clone(), None).unwrap_err();
619        assert_eq!(
620            err.to_string(),
621            "Invalid argument error: Offset of 11 exceeds length of values 10"
622        );
623
624        let err = BinaryArray::try_new(offsets.clone(), data, None).unwrap_err();
625        assert_eq!(
626            err.to_string(),
627            "Invalid argument error: Maximum offset of 11 is larger than values of length 10"
628        );
629
630        let non_ascii_data = Buffer::from_slice_ref("heìloworld");
631        StringArray::new(offsets.clone(), non_ascii_data.clone(), None);
632        BinaryArray::new(offsets, non_ascii_data.clone(), None);
633
634        let offsets = OffsetBuffer::new(vec![0, 3, 10].into());
635        let err = StringArray::try_new(offsets.clone(), non_ascii_data.clone(), None).unwrap_err();
636        assert_eq!(
637            err.to_string(),
638            "Invalid argument error: Split UTF-8 codepoint at offset 3"
639        );
640
641        BinaryArray::new(offsets, non_ascii_data, None);
642    }
643}
arrow_array/array/byte_array.rs

arrow_array/array/
byte_array.rs
