From 500377b8e70744a57b26cb279ec1dab2f8a366bb Mon Sep 17 00:00:00 2001
From: Raphael Taylor-Davies <r.taylordavies@googlemail.com>
Date: Mon, 3 Apr 2023 11:36:24 +0100
Subject: [PATCH] Deprecate combine_option_bitmap

---
 arrow-data/src/bit_mask.rs          |  3 +++
 arrow-string/src/concat_elements.rs | 14 ++++----------
 2 files changed, 7 insertions(+), 10 deletions(-)

diff --git a/arrow-data/src/bit_mask.rs b/arrow-data/src/bit_mask.rs
index 94ea57259ac8..d978f2b74618 100644
--- a/arrow-data/src/bit_mask.rs
+++ b/arrow-data/src/bit_mask.rs
@@ -68,6 +68,7 @@ pub fn set_bits(
 /// Combines the null bitmaps of multiple arrays using a bitwise `and` operation.
 ///
 /// This function is useful when implementing operations on higher level arrays.
+#[deprecated(note = "Use NullBuffer::union")]
 pub fn combine_option_bitmap(
     arrays: &[&ArrayData],
     len_in_bits: usize,
@@ -247,6 +248,7 @@ mod tests {
     }
 
     #[test]
+    #[allow(deprecated)]
     fn test_combine_option_bitmap() {
         let none_bitmap = make_data_with_null_bit_buffer(8, 0, None);
         let some_bitmap =
@@ -298,6 +300,7 @@ mod tests {
     }
 
     #[test]
+    #[allow(deprecated)]
     fn test_combine_option_bitmap_with_offsets() {
         let none_bitmap = make_data_with_null_bit_buffer(8, 0, None);
         let bitmap0 =
diff --git a/arrow-string/src/concat_elements.rs b/arrow-string/src/concat_elements.rs
index 4da9e2539e7e..a6e02d04dd3f 100644
--- a/arrow-string/src/concat_elements.rs
+++ b/arrow-string/src/concat_elements.rs
@@ -21,7 +21,6 @@ use arrow_array::builder::BufferBuilder;
 use arrow_array::types::ByteArrayType;
 use arrow_array::*;
 use arrow_buffer::{ArrowNativeType, NullBuffer};
-use arrow_data::bit_mask::combine_option_bitmap;
 use arrow_data::ArrayDataBuilder;
 use arrow_schema::{ArrowError, DataType};
 
@@ -125,14 +124,9 @@ pub fn concat_elements_utf8_many<Offset: OffsetSizeTrait>(
         )));
     }
 
-    let output_bitmap = combine_option_bitmap(
-        arrays
-            .iter()
-            .map(|a| a.data())
-            .collect::<Vec<_>>()
-            .as_slice(),
-        size,
-    );
+    let nulls = arrays
+        .iter()
+        .fold(None, |acc, a| NullBuffer::union(acc.as_ref(), a.nulls()));
 
     let data_values = arrays
         .iter()
@@ -170,7 +164,7 @@ pub fn concat_elements_utf8_many<Offset: OffsetSizeTrait>(
         .len(size)
         .add_buffer(output_offsets.finish())
         .add_buffer(output_values.finish())
-        .null_bit_buffer(output_bitmap);
+        .nulls(nulls);
 
     // SAFETY - offsets valid by construction
     Ok(unsafe { builder.build_unchecked() }.into())