Hi Micah, thanks for your suggestion. You are right, the mainly difference between FixSizedListVector and ListVector is the offsetBuffer, but I think this could be avoided through allocateNewSafe() overwrite which calls allocateOffsetBuffer() in BaseRepeatedValueVector, in this way, offsetBuffer in FixSizedListVector will remain allocator.getEmpty().
Meanwhile, we could add getStartIndex(int index)/getEndIndex(int index) API to handle read data logic respectively which could be used in getObject(int index) or encoding parts. What’s more, no new interface need to be introduced. What do you think? Thanks, Ji Liu ------------------------------------------------------------------ From:Micah Kornfield <emkornfi...@gmail.com> Send Time:2019年8月11日(星期日) 08:47 To:dev <dev@arrow.apache.org>; Ji Liu <niki...@aliyun.com> Subject:Re: [DISCUSS][JAVA] Make FixedSizedListVector inherit from ListVector Hi Ji Liu, I think have a common interface/base-class for the two makes sense (but don't have historical context) from a reading data perspective. I think the change would need to be something above BaseRepeatedValueVector, since the FixedSizeListVector doesn't contain an offset buffer, and that field is contained on BaseRepeatedValueVector. Thanks, Micah On Sat, Aug 10, 2019 at 5:25 PM Ji Liu <niki...@aliyun.com.invalid> wrote: Hi, all While working on the issue to implement dictionary-encoded subfields[1] [2], I found FixedSizeListVector not extends ListVector(Thanks Micah pointing this out and curious why implemented FixedSizeListVector this way before). Since FixedSizeListVector is a specific case of ListVector, should we make former extends the latter to reduce the plenty duplicated logic in these two and writer/reader classes? Thanks, Ji Liu [1] https://issues.apache.org/jira/browse/ARROW-1175[2]https://github.com/apache/arrow/pull/4972
