[arrow-rs] branch active_release updated: fix: new_null_array for structs (#736) (#760)

[al...@apache.org]

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alamb pushed a commit to branch active_release
in repository https://gitbox.apache.org/repos/asf/arrow-rs.git


The following commit(s) were added to refs/heads/active_release by this push:
     new b77b135  fix: new_null_array for structs (#736) (#760)
b77b135 is described below

commit b77b135c7932c129e2888c6b04bc345e300a33bc
Author: Andrew Lamb <an...@nerdnetworks.org>
AuthorDate: Fri Sep 10 05:38:45 2021 -0400

    fix: new_null_array for structs (#736) (#760)
    
    Co-authored-by: Ben Chambers <35...@users.noreply.github.com>
---
 arrow/src/array/array.rs | 36 +++++++++++++++++++++++++-----------
 1 file changed, 25 insertions(+), 11 deletions(-)

diff --git a/arrow/src/array/array.rs b/arrow/src/array/array.rs
index d715bc4..21fda04 100644
--- a/arrow/src/array/array.rs
+++ b/arrow/src/array/array.rs
@@ -440,18 +440,15 @@ pub fn new_null_array(data_type: &DataType, length: usize) -> ArrayRef {
                     .clone(),
             ],
         )),
-        DataType::Struct(fields) => make_array(ArrayData::new(
-            data_type.clone(),
-            length,
-            Some(length),
-            Some(MutableBuffer::new_null(length).into()),
-            0,
-            vec![],
-            fields
+        DataType::Struct(fields) => {
+            let fields: Vec<_> = fields
                 .iter()
-                .map(|field| ArrayData::new_empty(field.data_type()))
-                .collect(),
-        )),
+                .map(|field| (field.clone(), new_null_array(field.data_type(), length)))
+                .collect();
+
+            let null_buffer = MutableBuffer::new_null(length);
+            Arc::new(StructArray::from((fields, null_buffer.into())))
+        }
         DataType::Union(_) => {
             unimplemented!("Creating null Union array not yet supported")
         }
@@ -634,6 +631,23 @@ mod tests {
     }
 
     #[test]
+    fn test_null_struct() {
+        let struct_type =
+            DataType::Struct(vec![Field::new("data", DataType::Int64, false)]);
+        let array = new_null_array(&struct_type, 9);
+
+        let a = array.as_any().downcast_ref::<StructArray>().unwrap();
+        assert_eq!(a.len(), 9);
+        assert_eq!(a.column(0).len(), 9);
+        for i in 0..9 {
+            assert!(a.is_null(i));
+        }
+
+        // Make sure we can slice the resulting array.
+        a.slice(0, 5);
+    }
+
+    #[test]
     fn test_null_variable_sized() {
         let array = new_null_array(&DataType::Utf8, 9);
         let a = array.as_any().downcast_ref::<StringArray>().unwrap();