improve speed of view take kernel

Author: a10y

arrow-select/src/take.rs

@@ -485,13 +485,20 @@ fn take_byte_view<T: ByteViewType, IndexType: ArrowPrimitiveType>(
     array: &GenericByteViewArray<T>,
     indices: &PrimitiveArray<IndexType>,
 ) -> Result<GenericByteViewArray<T>, ArrowError> {
+    let data_len = indices.len();
+
     let new_views = take_native(array.views(), indices);
     let new_nulls = take_nulls(array.nulls(), indices);
-    Ok(GenericByteViewArray::new(
-        new_views,
-        array.data_buffers().to_vec(),
-        new_nulls,
-    ))
+
+    let array_data = ArrayData::builder(T::DATA_TYPE)
+        .len(data_len)
+        .add_buffer(new_views.into_inner())
+        .add_buffers(array.data_buffers().to_vec())
+        .nulls(new_nulls);
+
+    let array_data = unsafe { array_data.build_unchecked() };
+
+    Ok(GenericByteViewArray::from(array_data))
 }
 
 /// `take` implementation for list arrays

arrow/benches/take_kernels.rs

@@ -149,6 +149,42 @@ fn add_benchmark(c: &mut Criterion) {
         b.iter(|| bench_take(&values, &indices))
     });
 
+    let values = create_string_view_array(512, 0.0);
+    let indices = create_random_index(512, 0.0);
+    c.bench_function("take stringview 512", |b| {
+        b.iter(|| bench_take(&values, &indices))
+    });
+
+    let values = create_string_view_array(1024, 0.0);
+    let indices = create_random_index(1024, 0.0);
+    c.bench_function("take stringview 1024", |b| {
+        b.iter(|| bench_take(&values, &indices))
+    });
+
+    let values = create_string_view_array(512, 0.0);
+    let indices = create_random_index(512, 0.5);
+    c.bench_function("take stringview null indices 512", |b| {
+        b.iter(|| bench_take(&values, &indices))
+    });
+
+    let values = create_string_view_array(1024, 0.0);
+    let indices = create_random_index(1024, 0.5);
+    c.bench_function("take stringview null indices 1024", |b| {
+        b.iter(|| bench_take(&values, &indices))
+    });
+
+    let values = create_string_view_array(1024, 0.5);
+    let indices = create_random_index(1024, 0.0);
+    c.bench_function("take stringview null values 1024", |b| {
+        b.iter(|| bench_take(&values, &indices))
+    });
+
+    let values = create_string_view_array(1024, 0.5);
+    let indices = create_random_index(1024, 0.5);
+    c.bench_function("take stringview null values null indices 1024", |b| {
+        b.iter(|| bench_take(&values, &indices))
+    });
+
     let values = create_primitive_run_array::<Int32Type, Int32Type>(1024, 512);
     let indices = create_random_index(1024, 0.0);
     c.bench_function(

arrow/src/util/bench_util.rs

@@ -160,6 +160,34 @@ pub fn create_string_array_with_len<Offset: OffsetSizeTrait>(
         .collect()
 }
 
+/// Creates a random (but fixed-seeded) string view array of a given size and null density.
+///
+/// See `create_string_array` above for more details.
+pub fn create_string_view_array(size: usize, null_density: f32) -> StringViewArray {
+    create_string_view_array_with_max_len(size, null_density, 400)
+}
+
+/// Creates a random (but fixed-seeded) array of rand size with a given max size, null density and length
+fn create_string_view_array_with_max_len(
+    size: usize,
+    null_density: f32,
+    max_str_len: usize,
+) -> StringViewArray {
+    let rng = &mut seedable_rng();
+    (0..size)
+        .map(|_| {
+            if rng.gen::<f32>() < null_density {
+                None
+            } else {
+                let str_len = rng.gen_range(0..max_str_len);
+                let value = rng.sample_iter(&Alphanumeric).take(str_len).collect();
+                let value = String::from_utf8(value).unwrap();
+                Some(value)
+            }
+        })
+        .collect()
+}
+
 /// Creates a random (but fixed-seeded) array of a given size, null density and length
 pub fn create_string_view_array_with_len(
     size: usize,