Kikkon commented on code in PR #5723: URL: https://github.com/apache/arrow-rs/pull/5723#discussion_r1698524309
########## arrow-array/src/array/list_view_array.rs: ########## @@ -0,0 +1,938 @@ +// 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 std::any::Any; +use std::sync::Arc; + +use arrow_buffer::{NullBuffer, ScalarBuffer}; +use arrow_data::{ArrayData, ArrayDataBuilder}; +use arrow_schema::{ArrowError, DataType, FieldRef}; + +use crate::array::{make_array, print_long_array}; +use crate::iterator::GenericListViewArrayIter; +use crate::{new_empty_array, Array, ArrayAccessor, ArrayRef, FixedSizeListArray, OffsetSizeTrait}; + +/// 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 from [`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: ScalarBuffer<OffsetSize>, + value_sizes: ScalarBuffer<OffsetSize>, +} + +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(), + } + } +} + +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 + }; + + /// Create a new [`GenericListViewArray`] from the provided parts + /// + /// # Errors + /// + /// Errors if + /// + /// * `offsets.len() != sizes.len()` + /// * `offsets.len() != nulls.len()` + /// * `offsets.last() > values.len()` + /// * `!field.is_nullable() && values.is_nullable()` + /// * `field.data_type() != values.data_type()` + /// * `0 <= offsets[i] <= length of the child array` + /// * `0 <= offsets[i] + size[i] <= length of the child array` + pub fn try_new( + field: FieldRef, + offsets: ScalarBuffer<OffsetSize>, + sizes: ScalarBuffer<OffsetSize>, + values: ArrayRef, + nulls: Option<NullBuffer>, + ) -> Result<Self, ArrowError> { + let len = offsets.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 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() + ))); + } + + for i in 0..offsets.len() { + let length = values.len(); + let offset = offsets[i].as_usize(); + let size = sizes[i].as_usize(); + if offset > length { + return Err(ArrowError::InvalidArgumentError(format!( + "Invalid offset value for {}ListViewArray, offset: {}, length: {}", + OffsetSize::PREFIX, + offset, + length + ))); + } + if offset.saturating_add(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() + ))); + } + } + + if !field.is_nullable() && values.is_nullable() { + return Err(ArrowError::InvalidArgumentError(format!( + "Non-nullable field of {}ListViewArray {:?} cannot contain nulls", Review Comment: （： Aha, I directly referenced the error messages from the list array for this part to maintain consistency. -- This is an automated message from the Apache Git Service. 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