ZSTDArray::append_to_builder falls back to canonical for non utf8/binary dtypes

encodings/zstd/src/array.rs

@@ -289,14 +289,15 @@ impl VTable for Zstd {
         {
             return result;
         }
-        // The two arms here are every builder a `Utf8`/`Binary` dtype has: all four
-        // `VarBinBuilder` widths above, and `VarBinViewBuilder` below. There is deliberately no
-        // canonicalize-then-append fallback — it would decompress to a `VarBinView` only for
-        // `VarBinView::append_to_builder` to reject the same remainder.
-        let Some(builder) = builder.as_any_mut().downcast_mut::<VarBinViewBuilder>() else {
-            vortex_bail!("append_to_builder for Zstd requires a variable-binary builder")
-        };
-        append_to_varbinview(array, builder, ctx)
+        if let Some(builder) = builder.as_any_mut().downcast_mut::<VarBinViewBuilder>() {
+            return append_to_varbinview(array, builder, ctx);
+        }
+        array
+            .array()
+            .clone()
+            .execute::<Canonical>(ctx)?
+            .into_array()
+            .append_to_builder(builder, ctx)
     }
 
     fn reduce_parent(

encodings/zstd/src/test.rs

@@ -14,12 +14,14 @@ use vortex_array::assert_arrays_eq;
 use vortex_array::assert_nth_scalar;
 use vortex_array::builders::VarBinBuilder;
 use vortex_array::builders::VarBinViewBuilder;
+use vortex_array::builders::builder_with_capacity_in;
 use vortex_array::dtype::DType;
 use vortex_array::dtype::Nullability;
 use vortex_array::dtype::PType;
 use vortex_array::validity::Validity;
 use vortex_buffer::Alignment;
 use vortex_buffer::Buffer;
+use vortex_buffer::BufferAllocatorRef;
 use vortex_buffer::ByteBuffer;
 use vortex_error::VortexResult;
 use vortex_mask::Mask;
@@ -217,7 +219,28 @@ fn test_zstd_var_bin_view() {
 }
 
 #[test]
-fn test_zstd_append_to_offset_builder() {
+fn test_zstd_append_to_primitive_builder() -> VortexResult<()> {
+    let mut ctx = array_session().create_execution_ctx();
+    let array = PrimitiveArray::from_option_iter([Some(1_i32), None, Some(3), Some(4), Some(5)]);
+    let compressed = Zstd::from_primitive(&array, 0, 3, &mut ctx)?.slice(1..4)?;
+    let mut builder = builder_with_capacity_in(
+        compressed.dtype(),
+        compressed.len(),
+        BufferAllocatorRef::static_ref(),
+    );
+    compressed.append_to_builder(builder.as_mut(), &mut ctx)?;
+    assert_arrays_eq!(builder.finish(), array.into_array().slice(1..4)?, &mut ctx);
+    Ok(())
+}
+
+#[rstest]
+fn test_zstd_append_to_offset_builder(
+    #[values(
+        DType::Utf8(Nullability::Nullable),
+        DType::Binary(Nullability::Nullable)
+    )]
+    dtype: DType,
+) {
     let mut ctx = array_session().create_execution_ctx();
     let array = VarBinViewArray::from_iter(
         [
@@ -227,7 +250,7 @@ fn test_zstd_append_to_offset_builder() {
             Some(b"Lorem ipsum dolor sit amet".as_slice()),
             Some(b"baz".as_slice()),
         ],
-        DType::Utf8(Nullability::Nullable),
+        dtype,
     );
     let compressed = Zstd::from_var_bin_view(&array, 0, 3, &mut ctx)
         .unwrap()
@@ -236,7 +259,7 @@ fn test_zstd_append_to_offset_builder() {
     let mut builder = VarBinBuilder::<i32>::with_capacity_in(
         compressed.dtype().clone(),
         compressed.len(),
-        vortex_buffer::BufferAllocatorRef::static_ref(),
+        BufferAllocatorRef::static_ref(),
     );
     compressed
         .append_to_builder(&mut builder, &mut ctx)
@@ -267,7 +290,7 @@ fn test_zstd_append_to_view_builder_keeps_only_the_sliced_bytes() -> VortexResul
     let mut builder = VarBinViewBuilder::with_capacity_in(
         compressed.dtype().clone(),
         9,
-        vortex_buffer::BufferAllocatorRef::statically_allocated(),
+        BufferAllocatorRef::statically_allocated(),
     );
     builder.append_value(&values[0]);
     compressed.append_to_builder(&mut builder, &mut ctx)?;
@@ -383,7 +406,7 @@ fn test_zstd_rejects_corrupt_frame_metadata(
     let mut builder = VarBinBuilder::<i32>::with_capacity_in(
         compressed.dtype().clone(),
         compressed.len(),
-        vortex_buffer::BufferAllocatorRef::static_ref(),
+        BufferAllocatorRef::static_ref(),
     );
     assert!(
         compressed
@@ -424,17 +447,11 @@ fn test_zstd_rejects_a_frame_ending_in_a_dangling_length_prefix() -> VortexResul
     )?;
 
     assert!(Zstd::decompress(&compressed, &mut ctx).is_err());
-    let mut varbin = VarBinBuilder::<i32>::with_capacity_in(
-        dtype.clone(),
-        2,
-        vortex_buffer::BufferAllocatorRef::static_ref(),
-    );
+    let mut varbin =
+        VarBinBuilder::<i32>::with_capacity_in(dtype.clone(), 2, BufferAllocatorRef::static_ref());
     assert!(compressed.append_to_builder(&mut varbin, &mut ctx).is_err());
-    let mut views = VarBinViewBuilder::with_capacity_in(
-        dtype,
-        2,
-        vortex_buffer::BufferAllocatorRef::statically_allocated(),
-    );
+    let mut views =
+        VarBinViewBuilder::with_capacity_in(dtype, 2, BufferAllocatorRef::statically_allocated());
     assert!(compressed.append_to_builder(&mut views, &mut ctx).is_err());
     Ok(())
 }