viirya commented on code in PR #7865: URL: https://github.com/apache/arrow-rs/pull/7865#discussion_r2187517979
########## parquet-variant/src/builder.rs: ########## @@ -668,43 +739,41 @@ impl<'a, 'b> ObjectBuilder<'a, 'b> { self } - /// Return a new [`ObjectBuilder`] to add a nested object with the specified - /// key to the object. - pub fn new_object(&mut self, key: &'b str) -> ObjectBuilder { - self.check_pending_field(); - - let field_start = self.buffer.offset(); - let obj_builder = ObjectBuilder::new(&mut self.buffer, self.metadata_builder) - .with_validate_unique_fields(self.validate_unique_fields); - self.pending = Some((key, field_start)); - - obj_builder + // Returns validate_unique_fields because we can no longer reference self once this method returns. + fn parent_state<'b>(&'b mut self, key: &'b str) -> (ParentState<'b>, bool) { + let state = ParentState::Object { + buffer: &mut self.buffer, + metadata_builder: self.parent_state.metadata_builder(), + fields: &mut self.fields, + field_name: key, + }; + (state, self.validate_unique_fields) } - /// Return a new [`ListBuilder`] to add a list with the specified key to the - /// object. - pub fn new_list(&mut self, key: &'b str) -> ListBuilder { - self.check_pending_field(); - - let field_start = self.buffer.offset(); - let list_builder = ListBuilder::new(&mut self.buffer, self.metadata_builder) - .with_validate_unique_fields(self.validate_unique_fields); - self.pending = Some((key, field_start)); - - list_builder + /// Returns an object builder that can be used to append a new (nested) object to this list. + /// + /// WARNING: The builder will have no effect unless/until [`ObjectBuilder::finish`] is called. + pub fn new_object<'b>(&'b mut self, key: &'b str) -> ObjectBuilder<'b> { + let (parent_state, validate_unique_fields) = self.parent_state(key); + ObjectBuilder::new(parent_state, validate_unique_fields) } - /// Finalize object + /// Returns a list builder that can be used to append a new (nested) list to this list. /// - /// This consumes self and writes the object to the parent buffer. - pub fn finish(mut self) -> Result<(), ArrowError> { - self.check_pending_field(); + /// WARNING: The builder will have no effect unless/until [`ListBuilder::finish`] is called. + pub fn new_list<'b>(&'b mut self, key: &'b str) -> ListBuilder<'b> { + let (parent_state, validate_unique_fields) = self.parent_state(key); + ListBuilder::new(parent_state, validate_unique_fields) + } + /// Finalizes this object and appends it to its parent, which otherwise remains unmodified. + pub fn finish(mut self) -> Result<(), ArrowError> { + let metadata_builder = self.parent_state.metadata_builder(); Review Comment: > The new code doesn't insert a new object field's name to the metadata dictionary until the builder's finishmethod is called. Doesn't it? I saw that `insert` already modify the metadata builder. It is happened before `finish` is called, right? ```rust pub fn insert<'m, 'd, T: Into<Variant<'m, 'd>>>(&mut self, key: &str, value: T) { let metadata_builder = self.parent_state.metadata_builder(); let field_id = metadata_builder.upsert_field_name(key); // <- it is inserted into the metadata builder } ``` The only difference to previous code, is `check_pending_field` is removed now so if it is not finished, the field won't be updated to `fields` and no effect to `finish`. -- 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: github-unsubscr...@arrow.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org