[AURON #2320] Fix PB deserialization bug & improve PB parsing performance

native-engine/datafusion-ext-plans/src/flink/serde/json_deserializer.rs

@@ -1034,4 +1034,58 @@ mod tests {
         // msg2 missing "name" field, should get default empty string from ensure_size
         assert_eq!(name_col.value(1), "");
     }
+
+    /// Pin the omitted-vs-null distinction for a Boolean field that this PR
+    /// introduced by switching the shared `ensure_output_array_builders_size`
+    /// boolean default from `append_null()` to `append_value(false)`.
+    ///
+    /// After the change, the PB path correctly emits `false` for a proto3 field
+    /// absent from a message, but the shared default also reaches this JSON
+    /// path: an *omitted* boolean now yields a non-null `false`, while an
+    /// *explicit* JSON `null` still yields a null (the JSON handler appends
+    /// null for explicit nulls). This test locks that behavior so a future
+    /// change to either side is a conscious decision, not an accident.
+    #[test]
+    fn test_parse_json_boolean_omitted_vs_explicit_null() {
+        let schema = Arc::new(Schema::new(vec![
+            Field::new("serialized_kafka_records_partition", DataType::Int32, false),
+            Field::new("serialized_kafka_records_offset", DataType::Int64, false),
+            Field::new("serialized_kafka_records_timestamp", DataType::Int64, false),
+            Field::new("active", DataType::Boolean, true),
+        ]));
+
+        let nested_mapping = HashMap::new();
+        let mut deserializer = JsonDeserializer::new(schema.clone(), &nested_mapping)
+            .expect("Failed to create JsonDeserializer");
+
+        // row0: explicit true; row1: explicit null; row2: field omitted entirely.
+        let msg0 = br#"{"active": true}"#;
+        let msg1 = br#"{"active": null}"#;
+        let msg2 = br#"{}"#;
+
+        let messages = create_binary_array(vec![msg0.as_ref(), msg1.as_ref(), msg2.as_ref()]);
+        let partitions = create_partition_array(vec![0, 0, 0]);
+        let offsets = create_offset_array(vec![100, 101, 102]);
+        let timestamps = create_timestamp_array(vec![1000, 1001, 1002]);
+
+        let batch = deserializer
+            .parse_messages_with_kafka_meta(&messages, &partitions, &offsets, &timestamps)
+            .expect("Failed to parse messages");
+
+        assert_eq!(batch.num_rows(), 3);
+        let active_col = batch
+            .column(3)
+            .as_any()
+            .downcast_ref::<BooleanArray>()
+            .expect("active column");
+
+        // row0: explicit true.
+        assert!(active_col.value(0));
+        assert!(!active_col.is_null(0));
+        // row1: explicit null → null (JSON handler's own behavior).
+        assert!(active_col.is_null(1));
+        // row2: omitted → non-null false (shared ensure_size default).
+        assert!(!active_col.is_null(2));
+        assert!(!active_col.value(2));
+    }
 }