add rebuild to duckdb exporter

Signed-off-by: Matthew Katz <katz@spiraldb.com>

Author: Matthew Katz

vortex-array/public-api.lock

@@ -23082,6 +23082,8 @@ impl vortex_array::Array<vortex_array::arrays::ListView>
 
 pub fn vortex_array::Array<vortex_array::arrays::ListView>::rebuild(&self, vortex_array::arrays::listview::ListViewRebuildMode) -> vortex_error::VortexResult<vortex_array::arrays::ListViewArray>
 
+pub fn vortex_array::Array<vortex_array::arrays::ListView>::should_rebuild(&self, bool) -> bool
+
 impl vortex_array::Array<vortex_array::arrays::Masked>
 
 pub fn vortex_array::Array<vortex_array::arrays::Masked>::try_new(vortex_array::ArrayRef, vortex_array::validity::Validity) -> vortex_error::VortexResult<Self>

vortex-array/src/arrays/listview/rebuild.rs

@@ -389,7 +389,7 @@ impl ListViewArray {
         }
     }
 
-    fn should_rebuild(&self, exact: bool) -> bool {
+    pub fn should_rebuild(&self, exact: bool) -> bool {
         let density = if exact {
             self.compute_density()
         } else {

vortex-duckdb/src/exporter/list_view.rs

@@ -11,6 +11,7 @@ use vortex::array::ExecutionCtx;
 use vortex::array::arrays::ListViewArray;
 use vortex::array::arrays::PrimitiveArray;
 use vortex::array::arrays::listview::ListViewDataParts;
+use vortex::array::arrays::listview::ListViewRebuildMode;
 use vortex::array::match_each_integer_ptype;
 use vortex::array::validity::Validity;
 use vortex::dtype::IntegerPType;
@@ -50,13 +51,20 @@ pub(crate) fn new_exporter(
     ctx: &mut ExecutionCtx,
 ) -> VortexResult<Box<dyn ColumnExporter>> {
     let len = array.len();
+
+    let compact_array = if array.should_rebuild(false) {
+        array.rebuild(ListViewRebuildMode::MakeZeroCopyToList)?
+    } else {
+        array
+    };
+
     let ListViewDataParts {
         elements_dtype,
         elements,
         offsets,
         sizes,
         validity,
-    } = array.into_data_parts();
+    } = compact_array.into_data_parts();
     // Cache an `elements` vector up front so that future exports can reference it.
     let num_elements = elements.len();