tustvold commented on code in PR #5723:
URL: https://github.com/apache/arrow-rs/pull/5723#discussion_r1634855699


##########
arrow-array/src/array/list_view_array.rs:
##########
@@ -0,0 +1,990 @@
+// 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, ArrowPrimitiveType, 
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",
+                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,
+        })
+    }
+
+    /// Create a new [`GenericListViewArray`] from the provided parts
+    ///
+    /// # Panics
+    ///
+    /// Panics if [`Self::try_new`] returns an error
+    pub fn new(
+        field: FieldRef,
+        offsets: ScalarBuffer<OffsetSize>,
+        sizes: ScalarBuffer<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: ScalarBuffer::from(vec![]),
+            value_sizes: ScalarBuffer::from(vec![]),
+            values,
+        }
+    }
+
+    /// Deconstruct this array into its constituent parts
+    pub fn into_parts(
+        self,
+    ) -> (
+        FieldRef,
+        ScalarBuffer<OffsetSize>,
+        ScalarBuffer<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 [`ScalarBuffer`]
+    /// allowing for zero-copy cloning
+    #[inline]
+    pub fn offsets(&self) -> &ScalarBuffer<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 [`ScalarBuffer`]
+    /// allowing for zero-copy cloning
+    #[inline]
+    pub fn sizes(&self) -> &ScalarBuffer<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 offset = self.value_offsets()[i].as_usize();
+        let length = self.value_sizes()[i].as_usize();
+        self.values.slice(offset, length)
+    }
+
+    /// 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),
+        }
+    }
+
+    /// 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>>,
+    {
+        panic!("Not yet implemented, wait list view array builder to be 
implemented")
+    }
+}
+
+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.sizes().len()
+    }
+
+    fn is_empty(&self) -> bool {
+        self.values.is_empty()
+    }
+
+    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().capacity();
+        size += self.value_sizes.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().capacity();
+        size += self.value_sizes.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(),
+                array.value_sizes.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 iter = std::iter::repeat(size).take(value.len());
+        let mut offsets = Vec::with_capacity(iter.size_hint().0);
+        offsets.push(OffsetSize::usize_as(0));
+        let mut acc = 0_usize;
+        let iter = std::iter::repeat(size).take(value.len());
+        let mut sizes = Vec::with_capacity(iter.size_hint().0);
+        for size in iter {
+            acc = acc.checked_add(size).expect("usize overflow");
+            offsets.push(OffsetSize::usize_as(acc));
+            sizes.push(OffsetSize::usize_as(size));
+        }
+        OffsetSize::from_usize(acc).expect("offset overflow");
+        let sizes = ScalarBuffer::from(sizes);
+        let offsets = ScalarBuffer::from(offsets);
+        Self {
+            data_type: Self::DATA_TYPE_CONSTRUCTOR(field.clone()),
+            nulls: value.nulls().cloned(),
+            values: value.values().clone(),
+            value_offsets: offsets,
+            value_sizes: sizes,
+        }
+    }
+}
+
+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 = ScalarBuffer::new(data.buffers()[0].clone(), 
data.offset(), data.len());
+        let value_sizes = ScalarBuffer::new(data.buffers()[1].clone(), 
data.offset(), data.len());
+
+        Ok(Self {
+            data_type: data.data_type().clone(),
+            nulls: data.nulls().cloned(),
+            values,
+            value_offsets,
+            value_sizes,
+        })
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use arrow_buffer::{bit_util, BooleanBuffer, Buffer, ScalarBuffer};
+    use arrow_schema::Field;
+
+    use crate::builder::{FixedSizeListBuilder, Int32Builder};
+    use crate::cast::AsArray;
+    use crate::types::Int32Type;
+    use crate::{Int32Array, Int64Array};
+
+    use super::*;
+
+    #[test]
+    fn test_empty_list_view_array() {
+        // Construct an empty value array
+        let vec: Vec<i32> = vec![];
+        let field = Arc::new(Field::new("item", DataType::Int32, true));
+        let sizes = ScalarBuffer::from(vec![]);
+        let offsets = ScalarBuffer::from(vec![]);
+        let values = Int32Array::from(vec);
+        let list_array = LargeListViewArray::new(field, offsets, sizes, 
Arc::new(values), None);
+
+        assert_eq!(list_array.len(), 0)
+    }
+
+    #[test]
+    fn test_list_view_array() {
+        // Construct a value array
+        let value_data = ArrayData::builder(DataType::Int32)
+            .len(8)
+            .add_buffer(Buffer::from_slice_ref([0, 1, 2, 3, 4, 5, 6, 7]))
+            .build()
+            .unwrap();
+
+        let field = Arc::new(Field::new("item", DataType::Int32, true));
+        let sizes = ScalarBuffer::from(vec![3i32, 3, 2]);
+        let offsets = ScalarBuffer::from(vec![0i32, 3, 6]);
+        let values = Int32Array::from(vec![0, 1, 2, 3, 4, 5, 6, 7]);
+        let list_array = ListViewArray::new(field, offsets, sizes, 
Arc::new(values), None);
+
+        let values = list_array.values();
+        assert_eq!(value_data, values.to_data());
+        assert_eq!(DataType::Int32, list_array.value_type());
+        assert_eq!(3, list_array.len());
+        assert_eq!(0, list_array.null_count());
+        assert_eq!(6, list_array.value_offsets()[2]);
+        assert_eq!(2, list_array.value_sizes()[2]);
+        assert_eq!(2, list_array.value_length(2));
+        assert_eq!(
+            0,
+            list_array
+                .value(0)
+                .as_any()
+                .downcast_ref::<Int32Array>()
+                .unwrap()
+                .value(0)
+        );
+        assert_eq!(
+            0,
+            unsafe { list_array.value_unchecked(0) }
+                .as_any()
+                .downcast_ref::<Int32Array>()
+                .unwrap()
+                .value(0)
+        );
+        for i in 0..3 {
+            assert!(list_array.is_valid(i));
+            assert!(!list_array.is_null(i));
+        }
+    }
+
+    #[test]
+    fn test_large_list_view_array() {
+        // Construct a value array
+        let value_data = ArrayData::builder(DataType::Int32)
+            .len(8)
+            .add_buffer(Buffer::from_slice_ref([0, 1, 2, 3, 4, 5, 6, 7]))
+            .build()
+            .unwrap();
+
+        let field = Arc::new(Field::new("item", DataType::Int32, true));
+        let sizes = ScalarBuffer::from(vec![3i64, 3, 2]);
+        let offsets = ScalarBuffer::from(vec![0i64, 3, 6]);
+        let values = Int32Array::from(vec![0, 1, 2, 3, 4, 5, 6, 7]);
+        let list_array = LargeListViewArray::new(field, offsets, sizes, 
Arc::new(values), None);
+
+        let values = list_array.values();
+        assert_eq!(value_data, values.to_data());
+        assert_eq!(DataType::Int32, list_array.value_type());
+        assert_eq!(3, list_array.len());
+        assert_eq!(0, list_array.null_count());
+        assert_eq!(6, list_array.value_offsets()[2]);
+        assert_eq!(2, list_array.value_sizes()[2]);
+        assert_eq!(2, list_array.value_length(2));
+        assert_eq!(
+            0,
+            list_array
+                .value(0)
+                .as_any()
+                .downcast_ref::<Int32Array>()
+                .unwrap()
+                .value(0)
+        );
+        assert_eq!(
+            0,
+            unsafe { list_array.value_unchecked(0) }
+                .as_any()
+                .downcast_ref::<Int32Array>()
+                .unwrap()
+                .value(0)
+        );
+        for i in 0..3 {
+            assert!(list_array.is_valid(i));
+            assert!(!list_array.is_null(i));
+        }
+    }
+
+    #[test]
+    fn test_list_view_array_slice() {
+        // Construct a value array
+        let value_data = ArrayData::builder(DataType::Int32)
+            .len(10)
+            .add_buffer(Buffer::from_slice_ref([0, 1, 2, 3, 4, 5, 6, 7, 8, 9]))
+            .build()
+            .unwrap();
+
+        // 01011001 00000001
+        let mut null_bits: [u8; 2] = [0; 2];
+        bit_util::set_bit(&mut null_bits, 0);
+        bit_util::set_bit(&mut null_bits, 3);
+        bit_util::set_bit(&mut null_bits, 4);
+        bit_util::set_bit(&mut null_bits, 6);
+        bit_util::set_bit(&mut null_bits, 8);
+        let buffer = BooleanBuffer::new(Buffer::from(null_bits), 0, 9);
+        let null_buffer = NullBuffer::new(buffer);
+
+        let field = Arc::new(Field::new("item", DataType::Int32, true));
+        let sizes = ScalarBuffer::from(vec![2, 0, 0, 2, 2, 0, 3, 0, 1]);
+        let offsets = ScalarBuffer::from(vec![0, 2, 2, 2, 4, 6, 6, 9, 9]);
+        let values = Int32Array::from(vec![0, 1, 2, 3, 4, 5, 6, 7, 8, 9]);
+        let list_array =
+            ListViewArray::new(field, offsets, sizes, Arc::new(values), 
Some(null_buffer));
+
+        let values = list_array.values();
+        assert_eq!(value_data, values.to_data());
+        assert_eq!(DataType::Int32, list_array.value_type());
+        assert_eq!(9, list_array.len());
+        assert_eq!(4, list_array.null_count());
+        assert_eq!(2, list_array.value_offsets()[3]);
+        assert_eq!(2, list_array.value_sizes()[3]);
+        assert_eq!(2, list_array.value_length(3));
+
+        let sliced_array = list_array.slice(1, 6);
+        assert_eq!(6, sliced_array.len());
+        assert_eq!(3, sliced_array.null_count());
+
+        for i in 0..sliced_array.len() {
+            if bit_util::get_bit(&null_bits, 1 + i) {
+                assert!(sliced_array.is_valid(i));
+            } else {
+                assert!(sliced_array.is_null(i));
+            }
+        }
+
+        // Check offset and length for each non-null value.
+        let sliced_list_array = sliced_array
+            .as_any()
+            .downcast_ref::<ListViewArray>()
+            .unwrap();
+        assert_eq!(2, sliced_list_array.value_offsets()[2]);
+        assert_eq!(2, sliced_list_array.value_sizes()[2]);
+        assert_eq!(2, sliced_list_array.value_length(2));
+
+        assert_eq!(4, sliced_list_array.value_offsets()[3]);
+        assert_eq!(2, sliced_list_array.value_sizes()[3]);
+        assert_eq!(2, sliced_list_array.value_length(3));
+
+        assert_eq!(6, sliced_list_array.value_offsets()[5]);
+        assert_eq!(3, sliced_list_array.value_sizes()[5]);
+        assert_eq!(3, sliced_list_array.value_length(5));
+    }
+
+    #[test]
+    fn test_large_list_view_array_slice() {
+        // Construct a value array
+        let value_data = ArrayData::builder(DataType::Int32)
+            .len(10)
+            .add_buffer(Buffer::from_slice_ref([0, 1, 2, 3, 4, 5, 6, 7, 8, 9]))
+            .build()
+            .unwrap();
+
+        // 01011001 00000001
+        let mut null_bits: [u8; 2] = [0; 2];
+        bit_util::set_bit(&mut null_bits, 0);
+        bit_util::set_bit(&mut null_bits, 3);
+        bit_util::set_bit(&mut null_bits, 4);
+        bit_util::set_bit(&mut null_bits, 6);
+        bit_util::set_bit(&mut null_bits, 8);
+        let buffer = BooleanBuffer::new(Buffer::from(null_bits), 0, 9);
+        let null_buffer = NullBuffer::new(buffer);
+
+        // Construct a large list view array from the above two
+        let field = Arc::new(Field::new("item", DataType::Int32, true));
+        let sizes = ScalarBuffer::from(vec![2i64, 0, 0, 2, 2, 0, 3, 0, 1]);
+        let offsets = ScalarBuffer::from(vec![0i64, 2, 2, 2, 4, 6, 6, 9, 9]);
+        let values = Int32Array::from(vec![0, 1, 2, 3, 4, 5, 6, 7, 8, 9]);
+        let list_array =
+            LargeListViewArray::new(field, offsets, sizes, Arc::new(values), 
Some(null_buffer));
+
+        let values = list_array.values();
+        assert_eq!(value_data, values.to_data());
+        assert_eq!(DataType::Int32, list_array.value_type());
+        assert_eq!(9, list_array.len());
+        assert_eq!(4, list_array.null_count());
+        assert_eq!(2, list_array.value_offsets()[3]);
+        assert_eq!(2, list_array.value_sizes()[3]);
+        assert_eq!(2, list_array.value_length(3));
+
+        let sliced_array = list_array.slice(1, 6);
+        assert_eq!(6, sliced_array.len());
+        assert_eq!(3, sliced_array.null_count());
+
+        for i in 0..sliced_array.len() {
+            if bit_util::get_bit(&null_bits, 1 + i) {
+                assert!(sliced_array.is_valid(i));
+            } else {
+                assert!(sliced_array.is_null(i));
+            }
+        }
+
+        // Check offset and length for each non-null value.
+        let sliced_list_array = sliced_array
+            .as_any()
+            .downcast_ref::<LargeListViewArray>()
+            .unwrap();
+        assert_eq!(2, sliced_list_array.value_offsets()[2]);
+        assert_eq!(2, sliced_list_array.value_length(2));
+        assert_eq!(2, sliced_list_array.value_sizes()[2]);
+
+        assert_eq!(4, sliced_list_array.value_offsets()[3]);
+        assert_eq!(2, sliced_list_array.value_length(3));
+        assert_eq!(2, sliced_list_array.value_sizes()[3]);
+
+        assert_eq!(6, sliced_list_array.value_offsets()[5]);
+        assert_eq!(3, sliced_list_array.value_length(5));
+        assert_eq!(2, sliced_list_array.value_sizes()[3]);
+    }
+
+    #[test]
+    #[should_panic(expected = "index out of bounds: the len is 9 but the index 
is 10")]
+    fn test_list_view_array_index_out_of_bound() {
+        // 01011001 00000001
+        let mut null_bits: [u8; 2] = [0; 2];
+        bit_util::set_bit(&mut null_bits, 0);
+        bit_util::set_bit(&mut null_bits, 3);
+        bit_util::set_bit(&mut null_bits, 4);
+        bit_util::set_bit(&mut null_bits, 6);
+        bit_util::set_bit(&mut null_bits, 8);
+        let buffer = BooleanBuffer::new(Buffer::from(null_bits), 0, 9);
+        let null_buffer = NullBuffer::new(buffer);
+
+        // Construct a buffer for value offsets, for the nested array:
+        //  [[0, 1], null, null, [2, 3], [4, 5], null, [6, 7, 8], null, [9]]
+        // Construct a list array from the above two
+        let field = Arc::new(Field::new("item", DataType::Int32, true));
+        let sizes = ScalarBuffer::from(vec![2i32, 0, 0, 2, 2, 0, 3, 0, 1]);
+        let offsets = ScalarBuffer::from(vec![0i32, 2, 2, 2, 4, 6, 6, 9, 9]);
+        let values = Int32Array::from(vec![0, 1, 2, 3, 4, 5, 6, 7, 8, 9]);
+        let list_array =
+            ListViewArray::new(field, offsets, sizes, Arc::new(values), 
Some(null_buffer));
+
+        assert_eq!(9, list_array.len());
+        list_array.value(10);
+    }
+    #[test]
+    #[should_panic(
+        expected = "ListViewArray data should contain two buffer (value 
offsets & value size), had 0"
+    )]
+    #[cfg(not(feature = "force_validate"))]
+    fn test_list_view_array_invalid_buffer_len() {
+        let value_data = unsafe {
+            ArrayData::builder(DataType::Int32)
+                .len(8)
+                .add_buffer(Buffer::from_slice_ref([0, 1, 2, 3, 4, 5, 6, 7]))
+                .build_unchecked()
+        };
+        let list_data_type =
+            DataType::ListView(Arc::new(Field::new("item", DataType::Int32, 
false)));
+        let list_data = unsafe {
+            ArrayData::builder(list_data_type)
+                .len(3)
+                .add_child_data(value_data)
+                .build_unchecked()
+        };
+        drop(ListViewArray::from(list_data));
+    }
+
+    #[test]
+    #[should_panic(
+        expected = "ListViewArray data should contain two buffer (value 
offsets & value size), had 1"
+    )]
+    #[cfg(not(feature = "force_validate"))]
+    fn test_list_view_array_invalid_child_array_len() {
+        let value_offsets = Buffer::from_slice_ref([0, 2, 5, 7]);
+        let list_data_type =
+            DataType::ListView(Arc::new(Field::new("item", DataType::Int32, 
false)));
+        let list_data = unsafe {
+            ArrayData::builder(list_data_type)
+                .len(3)
+                .add_buffer(value_offsets)
+                .build_unchecked()
+        };
+        drop(ListViewArray::from(list_data));
+    }
+
+    #[test]
+    fn test_list_view_array_offsets_need_not_start_at_zero() {
+        let field = Arc::new(Field::new("item", DataType::Int32, true));
+        let sizes = ScalarBuffer::from(vec![0i32, 0, 3]);
+        let offsets = ScalarBuffer::from(vec![2i32, 2, 5]);
+        let values = Int32Array::from(vec![0, 1, 2, 3, 4, 5, 6, 7]);
+        let list_array = ListViewArray::new(field, offsets, sizes, 
Arc::new(values), None);
+
+        assert_eq!(list_array.value_length(0), 0);
+        assert_eq!(list_array.value_length(1), 0);
+        assert_eq!(list_array.value_length(2), 3);
+    }
+
+    #[test]
+    #[should_panic(expected = "Memory pointer is not aligned with the 
specified scalar type")]
+    #[cfg(not(feature = "force_validate"))]
+    fn test_list_view_array_alignment() {
+        let offset_buf = Buffer::from_slice_ref([0_u64]);
+        let offset_buf2 = offset_buf.slice(1);
+
+        let size_buf = Buffer::from_slice_ref([0_u64]);
+        let size_buf2 = size_buf.slice(1);
+
+        let values: [i32; 8] = [0; 8];
+        let value_data = unsafe {
+            ArrayData::builder(DataType::Int32)
+                .add_buffer(Buffer::from_slice_ref(values))
+                .build_unchecked()
+        };
+
+        let list_data_type =
+            DataType::ListView(Arc::new(Field::new("item", DataType::Int32, 
false)));
+        let list_data = unsafe {
+            ArrayData::builder(list_data_type)
+                .add_buffer(offset_buf2)
+                .add_buffer(size_buf2)
+                .add_child_data(value_data)
+                .build_unchecked()
+        };
+        drop(ListViewArray::from(list_data));
+    }
+
+    #[test]
+    fn test_empty_offsets() {
+        let f = Arc::new(Field::new("element", DataType::Int32, true));
+        let string = ListViewArray::from(
+            ArrayData::builder(DataType::ListView(f.clone()))
+                .buffers(vec![Buffer::from(&[]), Buffer::from(&[])])
+                .add_child_data(ArrayData::new_empty(&DataType::Int32))
+                .build()
+                .unwrap(),
+        );
+        assert_eq!(string.value_offsets(), &[]);
+        assert_eq!(string.value_sizes(), &[]);
+
+        let string = LargeListViewArray::from(
+            ArrayData::builder(DataType::LargeListView(f))
+                .buffers(vec![Buffer::from(&[]), Buffer::from(&[])])
+                .add_child_data(ArrayData::new_empty(&DataType::Int32))
+                .build()
+                .unwrap(),
+        );
+        assert_eq!(string.len(), 0);
+        assert_eq!(string.value_offsets(), &[]);
+        assert_eq!(string.value_sizes(), &[]);
+    }
+
+    #[test]
+    fn test_try_new() {
+        let offsets = ScalarBuffer::from(vec![0, 1, 4, 5]);
+        let sizes = ScalarBuffer::from(vec![1, 3, 1, 0]);
+        let values = Int32Array::new(vec![1, 2, 3, 4, 5].into(), None);
+        let values = Arc::new(values) as ArrayRef;
+
+        let field = Arc::new(Field::new("element", DataType::Int32, false));
+        ListViewArray::new(
+            field.clone(),
+            offsets.clone(),
+            sizes.clone(),
+            values.clone(),
+            None,
+        );
+
+        let nulls = NullBuffer::new_null(4);
+        ListViewArray::new(
+            field.clone(),
+            offsets,
+            sizes.clone(),
+            values.clone(),
+            Some(nulls),
+        );
+
+        let nulls = NullBuffer::new_null(4);
+        let offsets = ScalarBuffer::from(vec![0, 1, 2, 3, 4]);
+        let sizes = ScalarBuffer::from(vec![1, 1, 1, 1, 0]);
+        let err = LargeListViewArray::try_new(
+            field,
+            offsets.clone(),
+            sizes.clone(),
+            values.clone(),
+            Some(nulls),
+        )
+        .unwrap_err();
+
+        assert_eq!(
+            err.to_string(),
+            "Invalid argument error: Incorrect length of null buffer for 
LargeListViewArray, expected 5 got 4"
+        );
+
+        let field = Arc::new(Field::new("element", DataType::Int64, false));
+        let err = LargeListViewArray::try_new(
+            field.clone(),
+            offsets.clone(),
+            sizes.clone(),
+            values.clone(),
+            None,
+        )
+        .unwrap_err();
+
+        assert_eq!(
+            err.to_string(),
+            "Invalid argument error: LargeListViewArray expected data type 
Int64 got Int32 for \"element\""
+        );
+
+        let nulls = NullBuffer::new_null(7);
+        let values = Int64Array::new(vec![0; 7].into(), Some(nulls));
+        let values = Arc::new(values);
+
+        let err = LargeListViewArray::try_new(
+            field,
+            offsets.clone(),
+            sizes.clone(),
+            values.clone(),
+            None,
+        )
+        .unwrap_err();
+
+        assert_eq!(
+            err.to_string(),
+            "Invalid argument error: Non-nullable field of LargeListViewArray 
\"element\" cannot contain nulls"
+        );
+    }
+
+    #[test]
+    fn test_from_fixed_size_list() {
+        let mut builder = FixedSizeListBuilder::new(Int32Builder::new(), 3);
+        builder.values().append_slice(&[1, 2, 3]);
+        builder.append(true);
+        builder.values().append_slice(&[0, 0, 0]);
+        builder.append(false);
+        builder.values().append_slice(&[4, 5, 6]);
+        builder.append(true);
+        let list: ListViewArray = builder.finish().into();
+        let values: Vec<_> = list
+            .iter()
+            .map(|x| x.map(|x| 
x.as_primitive::<Int32Type>().values().to_vec()))
+            .collect();
+        assert_eq!(values, vec![Some(vec![1, 2, 3]), None, Some(vec![4, 5, 
6])])

Review Comment:
   Could we add tests of the offsets and sizes buffers, I think they're 
currently not quite correct



-- 
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.

To unsubscribe, e-mail: [email protected]

For queries about this service, please contact Infrastructure at:
[email protected]


Reply via email to