tustvold commented on code in PR #5576: URL: https://github.com/apache/arrow-rs/pull/5576#discussion_r1549265183
########## arrow-array/src/array/list_view_array.rs: ########## @@ -0,0 +1,1227 @@ +// Licensed to the Apache Software Foundation (ASF) under one +// or more contributor license agreements. See the NOTICE file +// distributed with this work for additional information +// regarding copyright ownership. The ASF licenses this file +// to you under the Apache License, Version 2.0 (the +// "License"); you may not use this file except in compliance +// with the License. You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, +// software distributed under the License is distributed on an +// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY +// KIND, either express or implied. See the License for the +// specific language governing permissions and limitations +// under the License. + +use crate::array::{get_offsets, get_sizes, make_array, print_long_array}; +use crate::builder::{GenericListViewBuilder, PrimitiveBuilder}; +use crate::iterator::GenericListViewArrayIter; +use crate::{ + new_empty_array, Array, ArrayAccessor, ArrayRef, ArrowPrimitiveType, FixedSizeListArray, + OffsetSizeTrait, +}; +use arrow_buffer::{NullBuffer, OffsetBuffer, SizeBuffer}; +use arrow_data::{ArrayData, ArrayDataBuilder}; +use arrow_schema::{ArrowError, DataType, FieldRef}; +use std::any::Any; +use std::ops::Add; +use std::sync::Arc; + +/// A [`GenericListViewArray`] of variable size lists, storing offsets as `i32`. +/// +// See [`ListViewBuilder`](crate::builder::ListViewBuilder) for how to construct a [`ListViewArray`] +pub type ListViewArray = GenericListViewArray<i32>; + +/// A [`GenericListViewArray`] of variable size lists, storing offsets as `i64`. +/// +// See [`LargeListViewArray`](crate::builder::LargeListViewBuilder) for how to construct a [`LargeListViewArray`] +pub type LargeListViewArray = GenericListViewArray<i64>; + +/// +/// Different than [`crate::GenericListArray`] as it stores both an offset and length +/// meaning that take / filter operations can be implemented without copying the underlying data. +/// +/// [Variable-size List Layout: ListView Layout]: https://arrow.apache.org/docs/format/Columnar.html#listview-layout +pub struct GenericListViewArray<OffsetSize: OffsetSizeTrait> { + data_type: DataType, + nulls: Option<NullBuffer>, + values: ArrayRef, + value_offsets: OffsetBuffer<OffsetSize>, + value_sizes: SizeBuffer<OffsetSize>, + len: usize, +} + +impl<OffsetSize: OffsetSizeTrait> Clone for GenericListViewArray<OffsetSize> { + fn clone(&self) -> Self { + Self { + data_type: self.data_type.clone(), + nulls: self.nulls.clone(), + values: self.values.clone(), + value_offsets: self.value_offsets.clone(), + value_sizes: self.value_sizes.clone(), + len: self.len, + } + } +} + +impl<OffsetSize: OffsetSizeTrait> GenericListViewArray<OffsetSize> { + /// The data type constructor of listview array. + /// The input is the schema of the child array and + /// the output is the [`DataType`], ListView or LargeListView. + pub const DATA_TYPE_CONSTRUCTOR: fn(FieldRef) -> DataType = if OffsetSize::IS_LARGE { + DataType::LargeListView + } else { + DataType::ListView + }; + + /// Returns the data type of the list view array + pub fn try_new( + field: FieldRef, + offsets: OffsetBuffer<OffsetSize>, + sizes: SizeBuffer<OffsetSize>, + values: ArrayRef, + nulls: Option<NullBuffer>, + ) -> Result<Self, ArrowError> { + let mut len = 0usize; + for i in 0..offsets.len() { + let offset = offsets[i].as_usize(); + let size = sizes[i].as_usize(); + if offset + size > values.len() { + return Err(ArrowError::InvalidArgumentError(format!( + "Invalid offset and size values for {}ListViewArray, offset: {}, size: {}, values.len(): {}", + OffsetSize::PREFIX, offset, size, values.len() + ))); + } + len = len.add(size); + } + + let len = offsets.len(); + if len != sizes.len() { + return Err(ArrowError::InvalidArgumentError(format!( + "Length of offsets buffer and sizes buffer must be equal for {}ListViewArray, got {} and {}", + OffsetSize::PREFIX, len, sizes.len() + ))); + } + + if let Some(n) = nulls.as_ref() { + if n.len() != len { + return Err(ArrowError::InvalidArgumentError(format!( + "Incorrect length of null buffer for {}ListViewArray, expected {len} got {}", + OffsetSize::PREFIX, + n.len(), + ))); + } + } + if !field.is_nullable() && values.is_nullable() { + return Err(ArrowError::InvalidArgumentError(format!( + "Non-nullable field of {}ListViewArray {:?} cannot contain nulls", + OffsetSize::PREFIX, + field.name() + ))); + } + + if field.data_type() != values.data_type() { + return Err(ArrowError::InvalidArgumentError(format!( + "{}ListViewArray expected data type {} got {} for {:?}", + OffsetSize::PREFIX, + field.data_type(), + values.data_type(), + field.name() + ))); + } + + Ok(Self { + data_type: Self::DATA_TYPE_CONSTRUCTOR(field), + nulls, + values, + value_offsets: offsets, + value_sizes: sizes, + len, + }) + } + + /// Create a new [`GenericListViewArray`] from the provided parts + /// + /// # Panics + /// + /// Panics if [`Self::try_new`] returns an error + pub fn new( + field: FieldRef, + offsets: OffsetBuffer<OffsetSize>, + sizes: SizeBuffer<OffsetSize>, + values: ArrayRef, + nulls: Option<NullBuffer>, + ) -> Self { + Self::try_new(field, offsets, sizes, values, nulls).unwrap() + } + + /// Create a new [`GenericListViewArray`] of length `len` where all values are null + pub fn new_null(field: FieldRef, len: usize) -> Self { + let values = new_empty_array(field.data_type()); + Self { + data_type: Self::DATA_TYPE_CONSTRUCTOR(field), + nulls: Some(NullBuffer::new_null(len)), + value_offsets: OffsetBuffer::new_zeroed(len), + value_sizes: SizeBuffer::new_zeroed(len), + values, + len: 0usize, + } + } + + /// Deconstruct this array into its constituent parts + pub fn into_parts( + self, + ) -> ( + FieldRef, + OffsetBuffer<OffsetSize>, + SizeBuffer<OffsetSize>, + ArrayRef, + Option<NullBuffer>, + ) { + let f = match self.data_type { + DataType::ListView(f) | DataType::LargeListView(f) => f, + _ => unreachable!(), + }; + ( + f, + self.value_offsets, + self.value_sizes, + self.values, + self.nulls, + ) + } + + /// Returns a reference to the offsets of this list + /// + /// Unlike [`Self::value_offsets`] this returns the [`OffsetBuffer`] + /// allowing for zero-copy cloning + #[inline] + pub fn offsets(&self) -> &OffsetBuffer<OffsetSize> { + &self.value_offsets + } + + /// Returns a reference to the values of this list + #[inline] + pub fn values(&self) -> &ArrayRef { + &self.values + } + + /// Returns a reference to the sizes of this list + /// + /// Unlike [`Self::value_sizes`] this returns the [`SizeBuffer`] + /// allowing for zero-copy cloning + #[inline] + pub fn sizes(&self) -> &SizeBuffer<OffsetSize> { + &self.value_sizes + } + + /// Returns a clone of the value type of this list. + pub fn value_type(&self) -> DataType { + self.values.data_type().clone() + } + + /// Returns ith value of this list view array. + /// # Safety + /// Caller must ensure that the index is within the array bounds + pub unsafe fn value_unchecked(&self, i: usize) -> ArrayRef { + let end = self.value_offsets().get_unchecked(i + 1).as_usize(); + let start = self.value_offsets().get_unchecked(i).as_usize(); + self.values.slice(start, end - start) + } + + /// Returns ith value of this list view array. + pub fn value(&self, i: usize) -> ArrayRef { + let offset = self.value_offsets()[i].as_usize(); + let length = self.value_sizes()[i].as_usize(); + self.values.slice(offset, length) + } + + /// Returns the offset values in the offsets buffer + #[inline] + pub fn value_offsets(&self) -> &[OffsetSize] { + &self.value_offsets + } + + /// Returns the sizes values in the offsets buffer + #[inline] + pub fn value_sizes(&self) -> &[OffsetSize] { + &self.value_sizes + } + + /// Returns the length for value at index `i`. + #[inline] + pub fn value_length(&self, i: usize) -> OffsetSize { + self.value_sizes[i] + } + + /// constructs a new iterator + pub fn iter<'a>(&'a self) -> GenericListViewArrayIter<'a, OffsetSize> { + GenericListViewArrayIter::<'a, OffsetSize>::new(self) + } + + #[inline] + fn get_type(data_type: &DataType) -> Option<&DataType> { + match (OffsetSize::IS_LARGE, data_type) { + (true, DataType::LargeListView(child)) | (false, DataType::ListView(child)) => { + Some(child.data_type()) + } + _ => None, + } + } + + /// Returns a zero-copy slice of this array with the indicated offset and length. + pub fn slice(&self, offset: usize, length: usize) -> Self { + Self { + data_type: self.data_type.clone(), + nulls: self.nulls.as_ref().map(|n| n.slice(offset, length)), + values: self.values.clone(), + value_offsets: self.value_offsets.slice(offset, length), + value_sizes: self.value_sizes.slice(offset, length), + len: length, + } + } + + /// Creates a [`GenericListViewArray`] from an iterator of primitive values + /// + pub fn from_iter_primitive<T, P, I>(iter: I) -> Self + where + T: ArrowPrimitiveType, + P: IntoIterator<Item = Option<<T as ArrowPrimitiveType>::Native>>, + I: IntoIterator<Item = Option<P>>, + { + let iter = iter.into_iter(); + let size_hint = iter.size_hint().0; + let mut builder = + GenericListViewBuilder::with_capacity(PrimitiveBuilder::<T>::new(), size_hint); + + for i in iter { + match i { + Some(p) => { + let mut size = 0usize; + for t in p { + builder.values().append_option(t); + size = size.add(1); + } + builder.append(true, size); + } + None => builder.append(false, 0), + } + } + builder.finish() + } +} + +impl<'a, OffsetSize: OffsetSizeTrait> ArrayAccessor for &'a GenericListViewArray<OffsetSize> { + type Item = ArrayRef; + + fn value(&self, index: usize) -> Self::Item { + GenericListViewArray::value(self, index) + } + + unsafe fn value_unchecked(&self, index: usize) -> Self::Item { + GenericListViewArray::value(self, index) + } +} + +impl<OffsetSize: OffsetSizeTrait> Array for GenericListViewArray<OffsetSize> { + fn as_any(&self) -> &dyn Any { + self + } + + fn to_data(&self) -> ArrayData { + self.clone().into() + } + + fn into_data(self) -> ArrayData { + self.into() + } + + fn data_type(&self) -> &DataType { + &self.data_type + } + + fn slice(&self, offset: usize, length: usize) -> ArrayRef { + Arc::new(self.slice(offset, length)) + } + + fn len(&self) -> usize { + self.len + } + + fn is_empty(&self) -> bool { + self.value_offsets.len() <= 1 + } + + fn offset(&self) -> usize { + 0 + } + + fn nulls(&self) -> Option<&NullBuffer> { + self.nulls.as_ref() + } + + fn get_buffer_memory_size(&self) -> usize { + let mut size = self.values.get_buffer_memory_size(); + size += self.value_offsets.inner().inner().capacity(); + if let Some(n) = self.nulls.as_ref() { + size += n.buffer().capacity(); + } + size + } + + fn get_array_memory_size(&self) -> usize { + let mut size = std::mem::size_of::<Self>() + self.values.get_array_memory_size(); + size += self.value_offsets.inner().inner().capacity(); + if let Some(n) = self.nulls.as_ref() { + size += n.buffer().capacity(); + } + size + } +} + +impl<OffsetSize: OffsetSizeTrait> std::fmt::Debug for GenericListViewArray<OffsetSize> { + fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result { + let prefix = OffsetSize::PREFIX; + write!(f, "{prefix}ListViewArray\n[\n")?; + print_long_array(self, f, |array, index, f| { + std::fmt::Debug::fmt(&array.value(index), f) + })?; + write!(f, "]") + } +} + +impl<OffsetSize: OffsetSizeTrait> From<GenericListViewArray<OffsetSize>> for ArrayData { + fn from(array: GenericListViewArray<OffsetSize>) -> Self { + let len = array.len(); + let builder = ArrayDataBuilder::new(array.data_type) + .len(len) + .nulls(array.nulls) + .buffers(vec![ + array.value_offsets.into_inner().into_inner(), + array.value_sizes.into_inner().into_inner(), + ]) + .child_data(vec![array.values.to_data()]); + + unsafe { builder.build_unchecked() } + } +} + +impl<OffsetSize: OffsetSizeTrait> From<ArrayData> for GenericListViewArray<OffsetSize> { + fn from(data: ArrayData) -> Self { + Self::try_new_from_array_data(data) + .expect("Expected infallible creation of GenericListViewArray from ArrayDataRef failed") + } +} + +impl<OffsetSize: OffsetSizeTrait> From<FixedSizeListArray> for GenericListViewArray<OffsetSize> { + fn from(value: FixedSizeListArray) -> Self { + let (field, size) = match value.data_type() { + DataType::FixedSizeList(f, size) => (f, *size as usize), + _ => unreachable!(), + }; + + let offsets = OffsetBuffer::from_lengths(std::iter::repeat(size).take(value.len())); + let sizes = SizeBuffer::from_lengths(std::iter::repeat(size).take(value.len())); + Self { + data_type: Self::DATA_TYPE_CONSTRUCTOR(field.clone()), + nulls: value.nulls().cloned(), + values: value.values().clone(), + value_offsets: offsets, + value_sizes: sizes, + len: value.len(), + } + } +} + +impl<OffsetSize: OffsetSizeTrait> GenericListViewArray<OffsetSize> { + fn try_new_from_array_data(data: ArrayData) -> Result<Self, ArrowError> { + if data.buffers().len() != 2 { + return Err(ArrowError::InvalidArgumentError(format!( + "ListViewArray data should contain two buffer (value offsets & value size), had {}", + data.buffers().len() + ))); + } + + if data.child_data().len() != 1 { + return Err(ArrowError::InvalidArgumentError(format!( + "ListViewArray should contain a single child array (values array), had {}", + data.child_data().len() + ))); + } + + let values = data.child_data()[0].clone(); + + if let Some(child_data_type) = Self::get_type(data.data_type()) { + if values.data_type() != child_data_type { + return Err(ArrowError::InvalidArgumentError(format!( + "[Large]ListViewArray's child datatype {:?} does not \ + correspond to the List's datatype {:?}", + values.data_type(), + child_data_type + ))); + } + } else { + return Err(ArrowError::InvalidArgumentError(format!( + "[Large]ListViewArray's datatype must be [Large]ListViewArray(). It is {:?}", + data.data_type() + ))); + } + + let values = make_array(values); + // SAFETY: + // ArrayData is valid, and verified type above + let value_offsets = unsafe { get_offsets(&data) }; + let value_sizes = unsafe { get_sizes(&data) }; + + Ok(Self { + data_type: data.data_type().clone(), + nulls: data.nulls().cloned(), + values, + value_offsets, + value_sizes, + len: data.len(), + }) + } +} + +#[cfg(test)] +mod tests { + use super::*; + use crate::builder::{FixedSizeListBuilder, Int32Builder, ListViewBuilder}; + use crate::cast::AsArray; + use crate::types::Int32Type; + use crate::{Int32Array, Int64Array}; + use arrow_buffer::{bit_util, Buffer, ScalarBuffer}; + use arrow_schema::DataType::LargeListView; + use arrow_schema::Field; + + fn create_from_buffers() -> ListViewArray { + // [[0, 1, 2], [3, 4, 5], [6, 7]] + let values = Int32Array::from(vec![0, 1, 2, 3, 4, 5, 6, 7]); + let offsets = OffsetBuffer::new(ScalarBuffer::from(vec![0, 3, 6])); + let field = Arc::new(Field::new("item", DataType::Int32, true)); + let sizes = SizeBuffer::new(ScalarBuffer::from(vec![3, 3, 2])); + + ListViewArray::new(field, offsets, sizes, Arc::new(values), None) + } + + #[test] + fn test_from_iter_primitive() { + let data = vec![ + Some(vec![Some(0), Some(1), Some(2)]), + Some(vec![Some(3), Some(4), Some(5)]), + Some(vec![Some(6), Some(7)]), + ]; + let list_array = ListViewArray::from_iter_primitive::<Int32Type, _, _>(data); + let another = create_from_buffers(); + assert_eq!(list_array, another) + } + + #[test] + fn test_empty_list_view_array() { + // Construct an empty value array + let value_data = ArrayData::builder(DataType::Int32) + .len(0) + .add_buffer(Buffer::from([])) + .build() + .unwrap(); + + // Construct an empty offset buffer + let value_offsets = Buffer::from([]); + // Construct an empty size buffer + let value_sizes = Buffer::from([]); + + // Construct a list view array from the above two + let list_data_type = + DataType::ListView(Arc::new(Field::new("item", DataType::Int32, false))); + let list_data = ArrayData::builder(list_data_type) + .len(0) + .add_buffer(value_offsets) + .add_buffer(value_sizes) + .add_child_data(value_data) + .build() + .unwrap(); + + let list_array = ListViewArray::from(list_data); + assert_eq!(list_array.len(), 0) + } + + #[test] Review Comment: Could we possibly use the constructors in these tests instead of ArrayData, this should be much easier to follow and maintain -- This is an automated message from the Apache Git Service. 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