Use NullBuffer in ArrayData (#3775) (#3778)

* Use NullBuffer in ArrayData (#3775)

* Clippy

* Format

* Doc

* Tweaks

* Review feedback

arrow-arith/src/aggregate.rs

@@ -117,8 +117,8 @@ where
             .map(|i| unsafe { array.value_unchecked(i) })
             .reduce(|acc, item| if cmp(&acc, &item) { item } else { acc })
     } else {
-        let null_buffer = array.data_ref().null_buffer().unwrap();
-        let iter = BitIndexIterator::new(null_buffer, array.offset(), array.len());
+        let nulls = array.data().nulls().unwrap();
+        let iter = BitIndexIterator::new(nulls.validity(), nulls.offset(), nulls.len());
         unsafe {
             let idx = iter.reduce(|acc_idx, idx| {
                 let acc = array.value_unchecked(acc_idx);
@@ -288,20 +288,20 @@ where
 
     let data: &[T::Native] = array.values();
 
-    match array.data().null_buffer() {
+    match array.data().nulls() {
         None => {
             let sum = data.iter().fold(T::default_value(), |accumulator, value| {
                 accumulator.add_wrapping(*value)
             });
 
             Some(sum)
         }
-        Some(buffer) => {
+        Some(nulls) => {
             let mut sum = T::default_value();
             let data_chunks = data.chunks_exact(64);
             let remainder = data_chunks.remainder();
 
-            let bit_chunks = buffer.bit_chunks(array.offset(), array.len());
+            let bit_chunks = nulls.inner().bit_chunks();
             data_chunks
                 .zip(bit_chunks.iter())
                 .for_each(|(chunk, mask)| {
@@ -347,7 +347,7 @@ where
 
     let data: &[T::Native] = array.values();
 
-    match array.data().null_buffer() {
+    match array.data().nulls() {
         None => {
             let sum = data
                 .iter()
@@ -357,14 +357,14 @@ where
 
             Ok(Some(sum))
         }
-        Some(buffer) => {
+        Some(nulls) => {
             let mut sum = T::default_value();
 
             try_for_each_valid_idx(
-                array.len(),
-                array.offset(),
-                null_count,
-                Some(buffer.as_slice()),
+                nulls.len(),
+                nulls.offset(),
+                nulls.null_count(),
+                Some(nulls.validity()),
                 |idx| {
                     unsafe { sum = sum.add_checked(array.value_unchecked(idx))? };
                     Ok::<_, ArrowError>(())
@@ -665,7 +665,7 @@ mod simd {
         let mut chunk_acc = A::init_accumulator_chunk();
         let mut rem_acc = A::init_accumulator_scalar();
 
-        match array.data().null_buffer() {
+        match array.data().nulls() {
             None => {
                 let data_chunks = data.chunks_exact(64);
                 let remainder = data_chunks.remainder();
@@ -681,12 +681,12 @@ mod simd {
                     A::accumulate_scalar(&mut rem_acc, *value);
                 });
             }
-            Some(buffer) => {
+            Some(nulls) => {
                 // process data in chunks of 64 elements since we also get 64 bits of validity information at a time
                 let data_chunks = data.chunks_exact(64);
                 let remainder = data_chunks.remainder();
 
-                let bit_chunks = buffer.bit_chunks(array.offset(), array.len());
+                let bit_chunks = nulls.inner().bit_chunks();
                 let remainder_bits = bit_chunks.remainder_bits();
 
                 data_chunks.zip(bit_chunks).for_each(|(chunk, mut mask)| {

arrow-arith/src/arithmetic.rs

@@ -1572,6 +1572,7 @@ mod tests {
     use arrow_array::builder::{
         BooleanBufferBuilder, BufferBuilder, PrimitiveDictionaryBuilder,
     };
+    use arrow_buffer::buffer::{BooleanBuffer, NullBuffer};
     use arrow_buffer::i256;
     use arrow_data::ArrayDataBuilder;
     use chrono::NaiveDate;
@@ -3057,15 +3058,19 @@ mod tests {
         // `count_set_bits_offset` takes len in bits as parameter.
         assert_eq!(null_buffer.count_set_bits_offset(0, 13), 0);
 
+        let nulls = BooleanBuffer::new(null_buffer, 0, 13);
+        assert_eq!(nulls.count_set_bits(), 0);
+        let nulls = NullBuffer::new(nulls);
+        assert_eq!(nulls.null_count(), 13);
+
         let mut data_buffer_builder = BufferBuilder::<i32>::new(13);
         data_buffer_builder.append_slice(&[0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12]);
         let data_buffer = data_buffer_builder.finish();
 
         let arg1: Int32Array = ArrayDataBuilder::new(DataType::Int32)
             .len(13)
-            .null_count(13)
+            .nulls(Some(nulls))
             .buffers(vec![data_buffer])
-            .null_bit_buffer(Some(null_buffer))
             .build()
             .unwrap()
             .into();
@@ -3078,9 +3083,7 @@ mod tests {
 
         let arg2: Int32Array = ArrayDataBuilder::new(DataType::Int32)
             .len(13)
-            .null_count(0)
             .buffers(vec![data_buffer])
-            .null_bit_buffer(None)
             .build()
             .unwrap()
             .into();

arrow-arith/src/arity.rs

@@ -20,6 +20,7 @@
 use arrow_array::builder::BufferBuilder;
 use arrow_array::iterator::ArrayIter;
 use arrow_array::*;
+use arrow_buffer::buffer::{BooleanBuffer, NullBuffer};
 use arrow_buffer::{Buffer, MutableBuffer};
 use arrow_data::bit_iterator::try_for_each_valid_idx;
 use arrow_data::bit_mask::combine_option_bitmap;
@@ -276,10 +277,7 @@ where
     let len = a.len();
 
     let null_buffer = combine_option_bitmap(&[a.data(), b.data()], len);
-    let null_count = null_buffer
-        .as_ref()
-        .map(|x| len - x.count_set_bits_offset(0, len))
-        .unwrap_or_default();
+    let nulls = null_buffer.map(|b| NullBuffer::new(BooleanBuffer::new(b, 0, len)));
 
     let mut builder = a.into_builder()?;
 
@@ -289,13 +287,7 @@ where
         .zip(b.values())
         .for_each(|(l, r)| *l = op(*l, *r));
 
-    let array_builder = builder
-        .finish()
-        .data()
-        .clone()
-        .into_builder()
-        .null_bit_buffer(null_buffer)
-        .null_count(null_count);
+    let array_builder = builder.finish().into_data().into_builder().nulls(nulls);
 
     let array_data = unsafe { array_builder.build_unchecked() };
     Ok(Ok(PrimitiveArray::<T>::from(array_data)))