Added support for MapArray read and write to parquet

src/array/fmt.rs

@@ -88,7 +88,9 @@ pub fn get_value_display<'a, F: Write + 'a>(
         Union => Box::new(move |f, index| {
             super::union::fmt::write_value(array.as_any().downcast_ref().unwrap(), index, null, f)
         }),
-        Map => todo!(),
+        Map => Box::new(move |f, index| {
+            super::map::fmt::write_value(array.as_any().downcast_ref().unwrap(), index, null, f)
+        }),
         Dictionary(key_type) => match_integer_type!(key_type, |$T| {
             Box::new(move |f, index| {
                 super::dictionary::fmt::write_value::<$T,_>(array.as_any().downcast_ref().unwrap(), index, null, f)

src/array/growable/map.rs

@@ -0,0 +1,113 @@
+use std::sync::Arc;
+
+use crate::{
+    array::{Array, MapArray},
+    bitmap::MutableBitmap,
+    offset::Offsets,
+};
+
+use super::{
+    make_growable,
+    utils::{build_extend_null_bits, ExtendNullBits},
+    Growable,
+};
+
+fn extend_offset_values(growable: &mut GrowableMap<'_>, index: usize, start: usize, len: usize) {
+    let array = growable.arrays[index];
+    let offsets = array.offsets();
+
+    growable
+        .offsets
+        .try_extend_from_slice(offsets, start, len)
+        .unwrap();
+
+    let end = offsets.buffer()[start + len] as usize;
+    let start = offsets.buffer()[start] as usize;
+    let len = end - start;
+    growable.values.extend(index, start, len);
+}
+
+/// Concrete [`Growable`] for the [`MapArray`].
+pub struct GrowableMap<'a> {
+    arrays: Vec<&'a MapArray>,
+    validity: MutableBitmap,
+    values: Box<dyn Growable<'a> + 'a>,
+    offsets: Offsets<i32>,
+    extend_null_bits: Vec<ExtendNullBits<'a>>,
+}
+
+impl<'a> GrowableMap<'a> {
+    /// Creates a new [`GrowableMap`] bound to `arrays` with a pre-allocated `capacity`.
+    /// # Panics
+    /// If `arrays` is empty.
+    pub fn new(arrays: Vec<&'a MapArray>, mut use_validity: bool, capacity: usize) -> Self {
+        // if any of the arrays has nulls, insertions from any array requires setting bits
+        // as there is at least one array with nulls.
+        if !use_validity & arrays.iter().any(|array| array.null_count() > 0) {
+            use_validity = true;
+        };
+
+        let extend_null_bits = arrays
+            .iter()
+            .map(|array| build_extend_null_bits(*array, use_validity))
+            .collect();
+
+        let inner = arrays
+            .iter()
+            .map(|array| array.field().as_ref())
+            .collect::<Vec<_>>();
+        let values = make_growable(&inner, use_validity, 0);
+
+        Self {
+            arrays,
+            offsets: Offsets::with_capacity(capacity),
+            values,
+            validity: MutableBitmap::with_capacity(capacity),
+            extend_null_bits,
+        }
+    }
+
+    fn to(&mut self) -> MapArray {
+        let validity = std::mem::take(&mut self.validity);
+        let offsets = std::mem::take(&mut self.offsets);
+        let values = self.values.as_box();
+
+        MapArray::new(
+            self.arrays[0].data_type().clone(),
+            offsets.into(),
+            values,
+            validity.into(),
+        )
+    }
+}
+
+impl<'a> Growable<'a> for GrowableMap<'a> {
+    fn extend(&mut self, index: usize, start: usize, len: usize) {
+        (self.extend_null_bits[index])(&mut self.validity, start, len);
+        extend_offset_values(self, index, start, len);
+    }
+
+    fn extend_validity(&mut self, additional: usize) {
+        self.offsets.extend_constant(additional);
+        self.validity.extend_constant(additional, false);
+    }
+
+    #[inline]
+    fn len(&self) -> usize {
+        self.offsets.len() - 1
+    }
+
+    fn as_arc(&mut self) -> Arc<dyn Array> {
+        Arc::new(self.to())
+    }
+
+    fn as_box(&mut self) -> Box<dyn Array> {
+        Box::new(self.to())
+    }
+}
+
+impl<'a> From<GrowableMap<'a>> for MapArray {
+    fn from(mut val: GrowableMap<'a>) -> Self {
+        val.to()
+    }
+}

src/array/growable/mod.rs

@@ -19,6 +19,8 @@ mod primitive;
 pub use primitive::GrowablePrimitive;
 mod list;
 pub use list::GrowableList;
+mod map;
+pub use map::GrowableMap;
 mod structure;
 pub use structure::GrowableStruct;
 mod fixed_size_list;
@@ -123,7 +125,7 @@ pub fn make_growable<'a>(
                 .collect::<Vec<_>>();
             Box::new(union::GrowableUnion::new(arrays, capacity))
         }
-        Map => todo!(),
+        Map => dyn_growable!(map::GrowableMap, arrays, use_validity, capacity),
         Dictionary(key_type) => {
             match_integer_type!(key_type, |$T| {
                 let arrays = arrays

src/array/map/mod.rs

@@ -8,7 +8,7 @@ use crate::{
 use super::{new_empty_array, specification::try_check_offsets_bounds, Array};
 
 mod ffi;
-mod fmt;
+pub(super) mod fmt;
 mod iterator;
 pub use iterator::*;
 

src/io/parquet/read/deserialize/mod.rs

@@ -15,7 +15,7 @@ use parquet2::read::get_page_iterator as _get_page_iterator;
 use parquet2::schema::types::PrimitiveType;
 
 use crate::{
-    array::{Array, DictionaryKey, FixedSizeListArray, ListArray},
+    array::{Array, DictionaryKey, FixedSizeListArray, ListArray, MapArray},
     datatypes::{DataType, Field, IntervalUnit},
     error::Result,
     offset::Offsets,
@@ -87,6 +87,33 @@ pub fn create_list(
     }
 }
 
+/// Creates a new [`MapArray`].
+pub fn create_map(
+    data_type: DataType,
+    nested: &mut NestedState,
+    values: Box<dyn Array>,
+) -> Box<dyn Array> {
+    let (mut offsets, validity) = nested.nested.pop().unwrap().inner();
+    match data_type.to_logical_type() {
+        DataType::Map(_, _) => {
+            offsets.push(values.len() as i64);
+            let offsets = offsets.iter().map(|x| *x as i32).collect::<Vec<_>>();
+
+            let offsets: Offsets<i32> = offsets
+                .try_into()
+                .expect("i64 offsets do not fit in i32 offsets");
+
+            Box::new(MapArray::new(
+                data_type,
+                offsets.into(),
+                values,
+                validity.and_then(|x| x.into()),
+            ))
+        }
+        _ => unreachable!(),
+    }
+}
+
 fn is_primitive(data_type: &DataType) -> bool {
     matches!(
         data_type.to_physical_type(),
@@ -147,6 +174,14 @@ pub fn n_columns(data_type: &DataType) -> usize {
                 unreachable!()
             }
         }
+        Map => {
+            let a = data_type.to_logical_type();
+            if let DataType::Map(inner, _) = a {
+                n_columns(&inner.data_type)
+            } else {
+                unreachable!()
+            }
+        }
         Struct => {
             if let DataType::Struct(fields) = data_type.to_logical_type() {
                 fields.iter().map(|inner| n_columns(&inner.data_type)).sum()

src/io/parquet/read/deserialize/nested.rs

@@ -1,7 +1,6 @@
 use parquet2::schema::types::PrimitiveType;
 
 use crate::{
-    array::MapArray,
     datatypes::{DataType, Field},
     error::{Error, Result},
 };
@@ -283,16 +282,12 @@ where
                     num_rows,
                     chunk_size,
                 )?;
-                Box::new(iter.map(move |x| {
-                    let (nested, inner) = x?;
-                    let array = MapArray::new(
-                        field.data_type().clone(),
-                        vec![0, inner.len() as i32].try_into().unwrap(),
-                        inner,
-                        None,
-                    );
-                    Ok((nested, array.boxed()))
-                }))
+                let iter = iter.map(move |x| {
+                    let (mut nested, array) = x?;
+                    let array = create_map(field.data_type().clone(), &mut nested, array);
+                    Ok((nested, array))
+                });
+                Box::new(iter) as _
             }
             other => {
                 return Err(Error::nyi(format!(

src/io/parquet/read/indexes/mod.rs

@@ -206,6 +206,13 @@ fn deserialize(
                 unreachable!()
             }
         }
+        PhysicalType::Map => {
+            if let DataType::Map(inner, _) = data_type.to_logical_type() {
+                deserialize(indexes, inner.data_type.clone())
+            } else {
+                unreachable!()
+            }
+        }
         PhysicalType::Struct => {
             let children_fields = if let DataType::Struct(children) = data_type.to_logical_type() {
                 children

src/io/parquet/read/mod.rs

@@ -35,8 +35,8 @@ pub use parquet2::{
 use crate::{array::Array, error::Result};
 
 pub use deserialize::{
-    column_iter_to_arrays, create_list, get_page_iterator, init_nested, n_columns, InitNested,
-    NestedArrayIter, NestedState, StructIterator,
+    column_iter_to_arrays, create_list, create_map, get_page_iterator, init_nested, n_columns,
+    InitNested, NestedArrayIter, NestedState, StructIterator,
 };
 pub use file::{FileReader, RowGroupReader};
 pub use row_group::*;

src/io/parquet/write/mod.rs

@@ -633,8 +633,20 @@ fn transverse_recursive<T, F: Fn(&DataType) -> T + Clone>(
                 unreachable!()
             }
         }
+        Map => {
+            if let DataType::Map(field, _) = data_type.to_logical_type() {
+                if let DataType::Struct(fields) = field.data_type.to_logical_type() {
+                    for field in fields {
+                        transverse_recursive(&field.data_type, map.clone(), encodings)
+                    }
+                } else {
+                    unreachable!()
+                }
+            } else {
+                unreachable!()
+            }
+        }
         Union => todo!(),
-        Map => todo!(),
     }
 }