Jefffrey commented on code in PR #10436:
URL: https://github.com/apache/arrow-rs/pull/10436#discussion_r3793424558
##########
arrow-cast/src/cast/dictionary.rs:
##########
@@ -126,6 +229,73 @@ fn dictionary_to_dictionary_cast<K:
ArrowDictionaryKeyType>(
Ok(new_array)
}
+/// Cast `Dict<K, Binary>` or `Dict<K, LargeBinary>` to `Utf8View`, validating
UTF-8 for each
+/// dictionary value.
+///
+/// Fast path when all values are valid UTF-8: reuses the values buffer
without copying.
+/// When some values are invalid and `cast_options.safe` is true, rows
pointing to those
+/// values become null. When `cast_options.safe` is false, returns an error
immediately.
+fn binary_dict_to_string_view<K: ArrowDictionaryKeyType, O: OffsetSizeTrait>(
+ keys: &PrimitiveArray<K>,
+ values: &GenericByteArray<GenericBinaryType<O>>,
+ cast_options: &CastOptions,
+) -> Result<ArrayRef, ArrowError> {
+ match GenericStringArray::<O>::try_from_binary(values.clone()) {
+ Ok(_) => {
+ // All dictionary values are valid UTF-8: reuse the buffer
zero-copy.
+ view_from_dict_values::<K, GenericBinaryType<O>,
StringViewType>(keys, values)
+ }
+ Err(e) => {
+ if !cast_options.safe {
+ return Err(e);
Review Comment:
thanks thats a good point, ill raise it as a separate issue
- https://github.com/apache/arrow-rs/issues/10711
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
To unsubscribe, e-mail: [email protected]
For queries about this service, please contact Infrastructure at:
[email protected]
