perf: list contains scalar scalar

Signed-off-by: Alexander Droste <[email protected]>

Author: 0ax1

vortex-array/src/expr/exprs/list_contains.rs

@@ -20,13 +20,14 @@ use vortex_error::vortex_err;
 use vortex_mask::Mask;
 use vortex_vector::BoolDatum;
 use vortex_vector::Datum;
-use vortex_vector::ScalarOps;
 use vortex_vector::Vector;
-use vortex_vector::VectorMutOps;
 use vortex_vector::VectorOps;
+use vortex_vector::bool::BoolScalar;
 use vortex_vector::bool::BoolVector;
 use vortex_vector::listview::ListViewScalar;
 use vortex_vector::listview::ListViewVector;
+use vortex_vector::match_each_pvector;
+use vortex_vector::primitive::PScalar;
 use vortex_vector::primitive::PVector;
 
 use crate::ArrayRef;
@@ -128,30 +129,34 @@ impl VTable for ListContains {
             .try_into()
             .map_err(|_| vortex_err!("Wrong number of arguments for ListContains expression"))?;
 
-        let matches = match (lhs.as_scalar().is_some(), rhs.as_scalar().is_some()) {
+        match (lhs.as_scalar().is_some(), rhs.as_scalar().is_some()) {
             (true, true) => {
+                // Early return with Scalar to avoid allocating BitBuffer.
                 let list = lhs.into_scalar().vortex_expect("scalar").into_list();
                 let needle = rhs.into_scalar().vortex_expect("scalar");
-                // Convert the needle scalar to a vector with row_count
-                // elements and reuse constant_list_scalar_contains
-                let needle_vector = needle.repeat(args.row_count).freeze();
-                constant_list_scalar_contains(list, needle_vector)?
+                let found = list_contains_scalar_scalar(&list, &needle)?;
+                Ok(Datum::Scalar(BoolScalar::new(Some(found)).into()))
+            }
+            (true, false) => {
+                let matches = constant_list_scalar_contains(
+                    lhs.into_scalar().vortex_expect("scalar").into_list(),
+                    rhs.into_vector().vortex_expect("vector"),
+                )?;
+                Ok(Datum::Vector(matches.into()))
+            }
+            (false, true) => {
+                let matches = list_contains_scalar(
+                    lhs.unwrap_into_vector(args.row_count).into_list(),
+                    rhs.into_scalar().vortex_expect("scalar").into_list(),
+                )?;
+                Ok(Datum::Vector(matches.into()))
             }
-            (true, false) => constant_list_scalar_contains(
-                lhs.into_scalar().vortex_expect("scalar").into_list(),
-                rhs.into_vector().vortex_expect("vector"),
-            )?,
-            (false, true) => list_contains_scalar(
-                lhs.unwrap_into_vector(args.row_count).into_list(),
-                rhs.into_scalar().vortex_expect("scalar").into_list(),
-            )?,
             (false, false) => {
                 vortex_bail!(
                     "ListContains currently only supports constant needle (RHS) or constant list (LHS)"
                 )
             }
-        };
-        Ok(Datum::Vector(matches.into()))
+        }
     }
 
     fn stat_falsification(
@@ -330,6 +335,31 @@ fn constant_list_scalar_contains(list: ListViewScalar, values: Vector) -> Vortex
     Ok(result)
 }
 
+/// Used when both needle and list are scalars.
+fn list_contains_scalar_scalar(
+    list: &ListViewScalar,
+    needle: &vortex_vector::Scalar,
+) -> VortexResult<bool> {
+    let elements = list.value().elements();
+
+    // Downcast to `PVector` and access slice directly to avoid `scalar_at` overhead.
+    let found = if let Vector::Primitive(prim) = &**elements {
+        match_each_pvector!(prim, |pvec| {
+            let slice: &[_] = pvec.as_ref();
+            let validity = pvec.validity();
+            slice
+                .iter()
+                .enumerate()
+                .any(|(i, &elem)| needle == &PScalar::new(Some(elem)).into() && validity.value(i))
+        })
+    } else {
+        // Fallback for non-primitive vectors
+        (0..elements.len()).any(|i| needle == &elements.scalar_at(i))
+    };
+
+    Ok(found)
+}
+
 /// Returns a [`BitBuffer`] where each bit represents if a list contains the scalar, derived from a
 /// [`BoolArray`] of matches on the child elements array.
 ///
@@ -366,6 +396,7 @@ where
 mod tests {
     use std::sync::Arc;
 
+    use rstest::rstest;
     use vortex_buffer::BitBuffer;
     use vortex_dtype::DType;
     use vortex_dtype::Field;
@@ -556,4 +587,57 @@ mod tests {
         let expr2 = list_contains(root(), lit(42));
         assert_eq!(expr2.to_string(), "contains($, 42i32)");
     }
+
+    #[rstest]
+    #[case(vec![1i32, 2i32, 3i32], 1i32, true, "first_element")]
+    #[case(vec![1i32, 2i32, 3i32], 2i32, true, "middle_element")]
+    #[case(vec![1i32, 2i32, 3i32], 3i32, true, "last_element")]
+    fn test_scalar_scalar_found(
+        #[case] list_values: Vec<i32>,
+        #[case] needle: i32,
+        #[case] expected: bool,
+        #[case] _description: &str,
+    ) {
+        let expr = list_contains(
+            lit(Scalar::list(
+                Arc::new(DType::Primitive(I32, Nullability::NonNullable)),
+                list_values
+                    .into_iter()
+                    .map(|v| Scalar::primitive(v, Nullability::NonNullable))
+                    .collect(),
+                Nullability::NonNullable,
+            )),
+            lit(needle),
+        );
+        let arr = test_array();
+        let result = expr.evaluate(&arr).unwrap();
+        assert_eq!(
+            result.scalar_at(0),
+            Scalar::bool(expected, Nullability::Nullable)
+        );
+    }
+
+    #[rstest]
+    #[case(0i32, false, "empty_list")]
+    #[case(1i32, false, "empty_list_seek_one")]
+    #[case(100i32, false, "empty_list_seek_large")]
+    fn test_scalar_scalar_not_found(
+        #[case] needle: i32,
+        #[case] expected: bool,
+        #[case] _description: &str,
+    ) {
+        let expr = list_contains(
+            lit(Scalar::list_empty(
+                Arc::new(DType::Primitive(I32, Nullability::NonNullable)),
+                Nullability::NonNullable,
+            )),
+            lit(needle),
+        );
+        let arr = test_array();
+        let result = expr.evaluate(&arr).unwrap();
+        assert_eq!(
+            result.scalar_at(0),
+            Scalar::bool(expected, Nullability::Nullable)
+        );
+    }
 }