From a89c1cf58161473b162fe1251d1da4cd09b25e36 Mon Sep 17 00:00:00 2001
From: Liang-Chi Hsieh <viirya@gmail.com>
Date: Thu, 30 Jun 2022 09:05:40 -0700
Subject: [PATCH] Support dictionary array for subtract and multiply kernel
 (#1971)

* Support dictionary array for subtract kernel

* Support dictionary array in multiply kernel
---
 arrow/src/compute/kernels/arithmetic.rs | 110 ++++++++++++++++++++++++
 1 file changed, 110 insertions(+)

diff --git a/arrow/src/compute/kernels/arithmetic.rs b/arrow/src/compute/kernels/arithmetic.rs
index 1f812b67e98..248e8df2770 100644
--- a/arrow/src/compute/kernels/arithmetic.rs
+++ b/arrow/src/compute/kernels/arithmetic.rs
@@ -720,6 +720,17 @@ where
     math_op(left, right, |a, b| a - b)
 }
 
+/// Perform `left - right` operation on two arrays. If either left or right value is null
+/// then the result is also null.
+pub fn subtract_dyn(left: &dyn Array, right: &dyn Array) -> Result<ArrayRef> {
+    match left.data_type() {
+        DataType::Dictionary(_, _) => {
+            typed_dict_math_op!(left, right, |a, b| a - b)
+        }
+        _ => typed_math_op!(left, right, |a, b| a - b),
+    }
+}
+
 /// Subtract every value in an array by a scalar. If any value in the array is null then the
 /// result is also null.
 pub fn subtract_scalar<T>(
@@ -771,6 +782,17 @@ where
     math_op(left, right, |a, b| a * b)
 }
 
+/// Perform `left * right` operation on two arrays. If either left or right value is null
+/// then the result is also null.
+pub fn multiply_dyn(left: &dyn Array, right: &dyn Array) -> Result<ArrayRef> {
+    match left.data_type() {
+        DataType::Dictionary(_, _) => {
+            typed_dict_math_op!(left, right, |a, b| a * b)
+        }
+        _ => typed_math_op!(left, right, |a, b| a * b),
+    }
+}
+
 /// Multiply every value in an array by a scalar. If any value in the array is null then the
 /// result is also null.
 pub fn multiply_scalar<T>(
@@ -936,6 +958,94 @@ mod tests {
         assert_eq!(19, c.value(4));
     }
 
+    #[test]
+    fn test_primitive_array_subtract_dyn() {
+        let a = Int32Array::from(vec![Some(51), Some(6), Some(15), Some(8), Some(9)]);
+        let b = Int32Array::from(vec![Some(6), Some(7), Some(8), None, Some(8)]);
+        let c = subtract_dyn(&a, &b).unwrap();
+        let c = c.as_any().downcast_ref::<Int32Array>().unwrap();
+        assert_eq!(45, c.value(0));
+        assert_eq!(-1, c.value(1));
+        assert_eq!(7, c.value(2));
+        assert!(c.is_null(3));
+        assert_eq!(1, c.value(4));
+    }
+
+    #[test]
+    fn test_primitive_array_subtract_dyn_dict() {
+        let key_builder = PrimitiveBuilder::<Int8Type>::new(3);
+        let value_builder = PrimitiveBuilder::<Int32Type>::new(2);
+        let mut builder = PrimitiveDictionaryBuilder::new(key_builder, value_builder);
+        builder.append(15).unwrap();
+        builder.append(8).unwrap();
+        builder.append(7).unwrap();
+        builder.append(8).unwrap();
+        builder.append(20).unwrap();
+        let a = builder.finish();
+
+        let key_builder = PrimitiveBuilder::<Int8Type>::new(3);
+        let value_builder = PrimitiveBuilder::<Int32Type>::new(2);
+        let mut builder = PrimitiveDictionaryBuilder::new(key_builder, value_builder);
+        builder.append(6).unwrap();
+        builder.append(7).unwrap();
+        builder.append(8).unwrap();
+        builder.append_null().unwrap();
+        builder.append(10).unwrap();
+        let b = builder.finish();
+
+        let c = subtract_dyn(&a, &b).unwrap();
+        let c = c.as_any().downcast_ref::<Int32Array>().unwrap();
+        assert_eq!(9, c.value(0));
+        assert_eq!(1, c.value(1));
+        assert_eq!(-1, c.value(2));
+        assert!(c.is_null(3));
+        assert_eq!(10, c.value(4));
+    }
+
+    #[test]
+    fn test_primitive_array_multiply_dyn() {
+        let a = Int32Array::from(vec![Some(5), Some(6), Some(7), Some(8), Some(9)]);
+        let b = Int32Array::from(vec![Some(6), Some(7), Some(8), None, Some(8)]);
+        let c = multiply_dyn(&a, &b).unwrap();
+        let c = c.as_any().downcast_ref::<Int32Array>().unwrap();
+        assert_eq!(30, c.value(0));
+        assert_eq!(42, c.value(1));
+        assert_eq!(56, c.value(2));
+        assert!(c.is_null(3));
+        assert_eq!(72, c.value(4));
+    }
+
+    #[test]
+    fn test_primitive_array_multiply_dyn_dict() {
+        let key_builder = PrimitiveBuilder::<Int8Type>::new(3);
+        let value_builder = PrimitiveBuilder::<Int32Type>::new(2);
+        let mut builder = PrimitiveDictionaryBuilder::new(key_builder, value_builder);
+        builder.append(5).unwrap();
+        builder.append(6).unwrap();
+        builder.append(7).unwrap();
+        builder.append(8).unwrap();
+        builder.append(9).unwrap();
+        let a = builder.finish();
+
+        let key_builder = PrimitiveBuilder::<Int8Type>::new(3);
+        let value_builder = PrimitiveBuilder::<Int32Type>::new(2);
+        let mut builder = PrimitiveDictionaryBuilder::new(key_builder, value_builder);
+        builder.append(6).unwrap();
+        builder.append(7).unwrap();
+        builder.append(8).unwrap();
+        builder.append_null().unwrap();
+        builder.append(10).unwrap();
+        let b = builder.finish();
+
+        let c = multiply_dyn(&a, &b).unwrap();
+        let c = c.as_any().downcast_ref::<Int32Array>().unwrap();
+        assert_eq!(30, c.value(0));
+        assert_eq!(42, c.value(1));
+        assert_eq!(56, c.value(2));
+        assert!(c.is_null(3));
+        assert_eq!(90, c.value(4));
+    }
+
     #[test]
     fn test_primitive_array_add_sliced() {
         let a = Int32Array::from(vec![0, 0, 0, 5, 6, 7, 8, 9, 0]);