use crate::array::{get_offsets, print_long_array};
use crate::iterator::MapArrayIter;
use crate::{make_array, Array, ArrayAccessor, ArrayRef, ListArray, StringArray, StructArray};
use arrow_buffer::{ArrowNativeType, Buffer, NullBuffer, OffsetBuffer, ToByteSlice};
use arrow_data::{ArrayData, ArrayDataBuilder};
use arrow_schema::{ArrowError, DataType, Field, FieldRef};
use std::any::Any;
use std::sync::Arc;
#[derive(Clone)]
pub struct MapArray {
data_type: DataType,
nulls: Option<NullBuffer>,
entries: StructArray,
value_offsets: OffsetBuffer<i32>,
}
impl MapArray {
pub fn try_new(
field: FieldRef,
offsets: OffsetBuffer<i32>,
entries: StructArray,
nulls: Option<NullBuffer>,
ordered: bool,
) -> Result<Self, ArrowError> {
let len = offsets.len() - 1; let end_offset = offsets.last().unwrap().as_usize();
if end_offset > entries.len() {
return Err(ArrowError::InvalidArgumentError(format!(
"Max offset of {end_offset} exceeds length of entries {}",
entries.len()
)));
}
if let Some(n) = nulls.as_ref() {
if n.len() != len {
return Err(ArrowError::InvalidArgumentError(format!(
"Incorrect length of null buffer for MapArray, expected {len} got {}",
n.len(),
)));
}
}
if field.is_nullable() || entries.null_count() != 0 {
return Err(ArrowError::InvalidArgumentError(
"MapArray entries cannot contain nulls".to_string(),
));
}
if field.data_type() != entries.data_type() {
return Err(ArrowError::InvalidArgumentError(format!(
"MapArray expected data type {} got {} for {:?}",
field.data_type(),
entries.data_type(),
field.name()
)));
}
if entries.columns().len() != 2 {
return Err(ArrowError::InvalidArgumentError(format!(
"MapArray entries must contain two children, got {}",
entries.columns().len()
)));
}
Ok(Self {
data_type: DataType::Map(field, ordered),
nulls,
entries,
value_offsets: offsets,
})
}
pub fn new(
field: FieldRef,
offsets: OffsetBuffer<i32>,
entries: StructArray,
nulls: Option<NullBuffer>,
ordered: bool,
) -> Self {
Self::try_new(field, offsets, entries, nulls, ordered).unwrap()
}
pub fn into_parts(
self,
) -> (
FieldRef,
OffsetBuffer<i32>,
StructArray,
Option<NullBuffer>,
bool,
) {
let (f, ordered) = match self.data_type {
DataType::Map(f, ordered) => (f, ordered),
_ => unreachable!(),
};
(f, self.value_offsets, self.entries, self.nulls, ordered)
}
#[inline]
pub fn offsets(&self) -> &OffsetBuffer<i32> {
&self.value_offsets
}
pub fn keys(&self) -> &ArrayRef {
self.entries.column(0)
}
pub fn values(&self) -> &ArrayRef {
self.entries.column(1)
}
pub fn entries(&self) -> &StructArray {
&self.entries
}
pub fn key_type(&self) -> &DataType {
self.keys().data_type()
}
pub fn value_type(&self) -> &DataType {
self.values().data_type()
}
pub unsafe fn value_unchecked(&self, i: usize) -> StructArray {
let end = *self.value_offsets().get_unchecked(i + 1);
let start = *self.value_offsets().get_unchecked(i);
self.entries
.slice(start.to_usize().unwrap(), (end - start).to_usize().unwrap())
}
pub fn value(&self, i: usize) -> StructArray {
let end = self.value_offsets()[i + 1] as usize;
let start = self.value_offsets()[i] as usize;
self.entries.slice(start, end - start)
}
#[inline]
pub fn value_offsets(&self) -> &[i32] {
&self.value_offsets
}
#[inline]
pub fn value_length(&self, i: usize) -> i32 {
let offsets = self.value_offsets();
offsets[i + 1] - offsets[i]
}
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)),
entries: self.entries.clone(),
value_offsets: self.value_offsets.slice(offset, length),
}
}
pub fn iter(&self) -> MapArrayIter<'_> {
MapArrayIter::new(self)
}
}
impl From<ArrayData> for MapArray {
fn from(data: ArrayData) -> Self {
Self::try_new_from_array_data(data)
.expect("Expected infallible creation of MapArray from ArrayData failed")
}
}
impl From<MapArray> for ArrayData {
fn from(array: MapArray) -> 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()])
.child_data(vec![array.entries.to_data()]);
unsafe { builder.build_unchecked() }
}
}
impl MapArray {
fn try_new_from_array_data(data: ArrayData) -> Result<Self, ArrowError> {
if !matches!(data.data_type(), DataType::Map(_, _)) {
return Err(ArrowError::InvalidArgumentError(format!(
"MapArray expected ArrayData with DataType::Map got {}",
data.data_type()
)));
}
if data.buffers().len() != 1 {
return Err(ArrowError::InvalidArgumentError(format!(
"MapArray data should contain a single buffer only (value offsets), had {}",
data.len()
)));
}
if data.child_data().len() != 1 {
return Err(ArrowError::InvalidArgumentError(format!(
"MapArray should contain a single child array (values array), had {}",
data.child_data().len()
)));
}
let entries = data.child_data()[0].clone();
if let DataType::Struct(fields) = entries.data_type() {
if fields.len() != 2 {
return Err(ArrowError::InvalidArgumentError(format!(
"MapArray should contain a struct array with 2 fields, have {} fields",
fields.len()
)));
}
} else {
return Err(ArrowError::InvalidArgumentError(format!(
"MapArray should contain a struct array child, found {:?}",
entries.data_type()
)));
}
let entries = entries.into();
let value_offsets = unsafe { get_offsets(&data) };
Ok(Self {
data_type: data.data_type().clone(),
nulls: data.nulls().cloned(),
entries,
value_offsets,
})
}
pub fn new_from_strings<'a>(
keys: impl Iterator<Item = &'a str>,
values: &dyn Array,
entry_offsets: &[u32],
) -> Result<Self, ArrowError> {
let entry_offsets_buffer = Buffer::from(entry_offsets.to_byte_slice());
let keys_data = StringArray::from_iter_values(keys);
let keys_field = Arc::new(Field::new("keys", DataType::Utf8, false));
let values_field = Arc::new(Field::new(
"values",
values.data_type().clone(),
values.null_count() > 0,
));
let entry_struct = StructArray::from(vec![
(keys_field, Arc::new(keys_data) as ArrayRef),
(values_field, make_array(values.to_data())),
]);
let map_data_type = DataType::Map(
Arc::new(Field::new(
"entries",
entry_struct.data_type().clone(),
false,
)),
false,
);
let map_data = ArrayData::builder(map_data_type)
.len(entry_offsets.len() - 1)
.add_buffer(entry_offsets_buffer)
.add_child_data(entry_struct.into_data())
.build()?;
Ok(MapArray::from(map_data))
}
}
impl Array for MapArray {
fn as_any(&self) -> &dyn Any {
self
}
fn to_data(&self) -> ArrayData {
self.clone().into_data()
}
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.value_offsets.len() - 1
}
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.entries.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.entries.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 ArrayAccessor for &MapArray {
type Item = StructArray;
fn value(&self, index: usize) -> Self::Item {
MapArray::value(self, index)
}
unsafe fn value_unchecked(&self, index: usize) -> Self::Item {
MapArray::value(self, index)
}
}
impl std::fmt::Debug for MapArray {
fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
write!(f, "MapArray\n[\n")?;
print_long_array(self, f, |array, index, f| {
std::fmt::Debug::fmt(&array.value(index), f)
})?;
write!(f, "]")
}
}
impl From<MapArray> for ListArray {
fn from(value: MapArray) -> Self {
let field = match value.data_type() {
DataType::Map(field, _) => field,
_ => unreachable!("This should be a map type."),
};
let data_type = DataType::List(field.clone());
let builder = value.into_data().into_builder().data_type(data_type);
let array_data = unsafe { builder.build_unchecked() };
ListArray::from(array_data)
}
}
#[cfg(test)]
mod tests {
use crate::cast::AsArray;
use crate::types::UInt32Type;
use crate::{Int32Array, UInt32Array};
use arrow_schema::Fields;
use super::*;
fn create_from_buffers() -> MapArray {
let keys_data = ArrayData::builder(DataType::Int32)
.len(8)
.add_buffer(Buffer::from([0, 1, 2, 3, 4, 5, 6, 7].to_byte_slice()))
.build()
.unwrap();
let values_data = ArrayData::builder(DataType::UInt32)
.len(8)
.add_buffer(Buffer::from(
[0u32, 10, 20, 30, 40, 50, 60, 70].to_byte_slice(),
))
.build()
.unwrap();
let entry_offsets = Buffer::from([0, 3, 6, 8].to_byte_slice());
let keys = Arc::new(Field::new("keys", DataType::Int32, false));
let values = Arc::new(Field::new("values", DataType::UInt32, false));
let entry_struct = StructArray::from(vec![
(keys, make_array(keys_data)),
(values, make_array(values_data)),
]);
let map_data_type = DataType::Map(
Arc::new(Field::new(
"entries",
entry_struct.data_type().clone(),
false,
)),
false,
);
let map_data = ArrayData::builder(map_data_type)
.len(3)
.add_buffer(entry_offsets)
.add_child_data(entry_struct.into_data())
.build()
.unwrap();
MapArray::from(map_data)
}
#[test]
fn test_map_array() {
let key_data = ArrayData::builder(DataType::Int32)
.len(8)
.add_buffer(Buffer::from([0, 1, 2, 3, 4, 5, 6, 7].to_byte_slice()))
.build()
.unwrap();
let value_data = ArrayData::builder(DataType::UInt32)
.len(8)
.add_buffer(Buffer::from(
[0u32, 10, 20, 0, 40, 0, 60, 70].to_byte_slice(),
))
.null_bit_buffer(Some(Buffer::from(&[0b11010110])))
.build()
.unwrap();
let entry_offsets = Buffer::from([0, 3, 6, 8].to_byte_slice());
let keys_field = Arc::new(Field::new("keys", DataType::Int32, false));
let values_field = Arc::new(Field::new("values", DataType::UInt32, true));
let entry_struct = StructArray::from(vec![
(keys_field.clone(), make_array(key_data)),
(values_field.clone(), make_array(value_data.clone())),
]);
let map_data_type = DataType::Map(
Arc::new(Field::new(
"entries",
entry_struct.data_type().clone(),
false,
)),
false,
);
let map_data = ArrayData::builder(map_data_type)
.len(3)
.add_buffer(entry_offsets)
.add_child_data(entry_struct.into_data())
.build()
.unwrap();
let map_array = MapArray::from(map_data);
assert_eq!(value_data, map_array.values().to_data());
assert_eq!(&DataType::UInt32, map_array.value_type());
assert_eq!(3, map_array.len());
assert_eq!(0, map_array.null_count());
assert_eq!(6, map_array.value_offsets()[2]);
assert_eq!(2, map_array.value_length(2));
let key_array = Arc::new(Int32Array::from(vec![0, 1, 2])) as ArrayRef;
let value_array =
Arc::new(UInt32Array::from(vec![None, Some(10u32), Some(20)])) as ArrayRef;
let struct_array = StructArray::from(vec![
(keys_field.clone(), key_array),
(values_field.clone(), value_array),
]);
assert_eq!(
struct_array,
StructArray::from(map_array.value(0).into_data())
);
assert_eq!(
&struct_array,
unsafe { map_array.value_unchecked(0) }
.as_any()
.downcast_ref::<StructArray>()
.unwrap()
);
for i in 0..3 {
assert!(map_array.is_valid(i));
assert!(!map_array.is_null(i));
}
let map_array = map_array.slice(1, 2);
assert_eq!(value_data, map_array.values().to_data());
assert_eq!(&DataType::UInt32, map_array.value_type());
assert_eq!(2, map_array.len());
assert_eq!(0, map_array.null_count());
assert_eq!(6, map_array.value_offsets()[1]);
assert_eq!(2, map_array.value_length(1));
let key_array = Arc::new(Int32Array::from(vec![3, 4, 5])) as ArrayRef;
let value_array = Arc::new(UInt32Array::from(vec![None, Some(40), None])) as ArrayRef;
let struct_array =
StructArray::from(vec![(keys_field, key_array), (values_field, value_array)]);
assert_eq!(
&struct_array,
map_array
.value(0)
.as_any()
.downcast_ref::<StructArray>()
.unwrap()
);
assert_eq!(
&struct_array,
unsafe { map_array.value_unchecked(0) }
.as_any()
.downcast_ref::<StructArray>()
.unwrap()
);
}
#[test]
#[ignore = "Test fails because slice of <list<struct>> is still buggy"]
fn test_map_array_slice() {
let map_array = create_from_buffers();
let sliced_array = map_array.slice(1, 2);
assert_eq!(2, sliced_array.len());
assert_eq!(1, sliced_array.offset());
let sliced_array_data = sliced_array.to_data();
for array_data in sliced_array_data.child_data() {
assert_eq!(array_data.offset(), 1);
}
let sliced_map_array = sliced_array.as_any().downcast_ref::<MapArray>().unwrap();
assert_eq!(3, sliced_map_array.value_offsets()[0]);
assert_eq!(3, sliced_map_array.value_length(0));
assert_eq!(6, sliced_map_array.value_offsets()[1]);
assert_eq!(2, sliced_map_array.value_length(1));
let keys_data = ArrayData::builder(DataType::Int32)
.len(5)
.add_buffer(Buffer::from([3, 4, 5, 6, 7].to_byte_slice()))
.build()
.unwrap();
let values_data = ArrayData::builder(DataType::UInt32)
.len(5)
.add_buffer(Buffer::from([30u32, 40, 50, 60, 70].to_byte_slice()))
.build()
.unwrap();
let entry_offsets = Buffer::from([0, 3, 5].to_byte_slice());
let keys = Arc::new(Field::new("keys", DataType::Int32, false));
let values = Arc::new(Field::new("values", DataType::UInt32, false));
let entry_struct = StructArray::from(vec![
(keys, make_array(keys_data)),
(values, make_array(values_data)),
]);
let map_data_type = DataType::Map(
Arc::new(Field::new(
"entries",
entry_struct.data_type().clone(),
false,
)),
false,
);
let expected_map_data = ArrayData::builder(map_data_type)
.len(2)
.add_buffer(entry_offsets)
.add_child_data(entry_struct.into_data())
.build()
.unwrap();
let expected_map_array = MapArray::from(expected_map_data);
assert_eq!(&expected_map_array, sliced_map_array)
}
#[test]
#[should_panic(expected = "index out of bounds: the len is ")]
fn test_map_array_index_out_of_bound() {
let map_array = create_from_buffers();
map_array.value(map_array.len());
}
#[test]
#[should_panic(expected = "MapArray expected ArrayData with DataType::Map got Dictionary")]
fn test_from_array_data_validation() {
let struct_t = DataType::Struct(Fields::from(vec![
Field::new("keys", DataType::Int32, true),
Field::new("values", DataType::UInt32, true),
]));
let dict_t = DataType::Dictionary(Box::new(DataType::Int32), Box::new(struct_t));
let _ = MapArray::from(ArrayData::new_empty(&dict_t));
}
#[test]
fn test_new_from_strings() {
let keys = vec!["a", "b", "c", "d", "e", "f", "g", "h"];
let values_data = UInt32Array::from(vec![0u32, 10, 20, 30, 40, 50, 60, 70]);
let entry_offsets = [0, 3, 6, 8];
let map_array =
MapArray::new_from_strings(keys.clone().into_iter(), &values_data, &entry_offsets)
.unwrap();
assert_eq!(
&values_data,
map_array.values().as_primitive::<UInt32Type>()
);
assert_eq!(&DataType::UInt32, map_array.value_type());
assert_eq!(3, map_array.len());
assert_eq!(0, map_array.null_count());
assert_eq!(6, map_array.value_offsets()[2]);
assert_eq!(2, map_array.value_length(2));
let key_array = Arc::new(StringArray::from(vec!["a", "b", "c"])) as ArrayRef;
let value_array = Arc::new(UInt32Array::from(vec![0u32, 10, 20])) as ArrayRef;
let keys_field = Arc::new(Field::new("keys", DataType::Utf8, false));
let values_field = Arc::new(Field::new("values", DataType::UInt32, false));
let struct_array =
StructArray::from(vec![(keys_field, key_array), (values_field, value_array)]);
assert_eq!(
struct_array,
StructArray::from(map_array.value(0).into_data())
);
assert_eq!(
&struct_array,
unsafe { map_array.value_unchecked(0) }
.as_any()
.downcast_ref::<StructArray>()
.unwrap()
);
for i in 0..3 {
assert!(map_array.is_valid(i));
assert!(!map_array.is_null(i));
}
}
#[test]
fn test_try_new() {
let offsets = OffsetBuffer::new(vec![0, 1, 4, 5].into());
let fields = Fields::from(vec![
Field::new("key", DataType::Int32, false),
Field::new("values", DataType::Int32, false),
]);
let columns = vec![
Arc::new(Int32Array::from(vec![1, 2, 3, 4, 5])) as _,
Arc::new(Int32Array::from(vec![1, 2, 3, 4, 5])) as _,
];
let entries = StructArray::new(fields.clone(), columns, None);
let field = Arc::new(Field::new("entries", DataType::Struct(fields), false));
MapArray::new(field.clone(), offsets.clone(), entries.clone(), None, false);
let nulls = NullBuffer::new_null(3);
MapArray::new(field.clone(), offsets, entries.clone(), Some(nulls), false);
let nulls = NullBuffer::new_null(3);
let offsets = OffsetBuffer::new(vec![0, 1, 2, 4, 5].into());
let err = MapArray::try_new(
field.clone(),
offsets.clone(),
entries.clone(),
Some(nulls),
false,
)
.unwrap_err();
assert_eq!(
err.to_string(),
"Invalid argument error: Incorrect length of null buffer for MapArray, expected 4 got 3"
);
let err = MapArray::try_new(field, offsets.clone(), entries.slice(0, 2), None, false)
.unwrap_err();
assert_eq!(
err.to_string(),
"Invalid argument error: Max offset of 5 exceeds length of entries 2"
);
let field = Arc::new(Field::new("element", DataType::Int64, false));
let err = MapArray::try_new(field, offsets.clone(), entries, None, false)
.unwrap_err()
.to_string();
assert!(
err.starts_with("Invalid argument error: MapArray expected data type Int64 got Struct"),
"{err}"
);
let fields = Fields::from(vec![
Field::new("a", DataType::Int32, false),
Field::new("b", DataType::Int32, false),
Field::new("c", DataType::Int32, false),
]);
let columns = vec![
Arc::new(Int32Array::from(vec![1, 2, 3, 4, 5])) as _,
Arc::new(Int32Array::from(vec![1, 2, 3, 4, 5])) as _,
Arc::new(Int32Array::from(vec![1, 2, 3, 4, 5])) as _,
];
let s = StructArray::new(fields.clone(), columns, None);
let field = Arc::new(Field::new("entries", DataType::Struct(fields), false));
let err = MapArray::try_new(field, offsets, s, None, false).unwrap_err();
assert_eq!(
err.to_string(),
"Invalid argument error: MapArray entries must contain two children, got 3"
);
}
}