[ARROW-8516] [Rust] Slow BufferBuilder<BooleanType> inserts within PrimitiveBuilder::append_slice

• Type: Improvement
• Status: Resolved
• Priority: Trivial
• Resolution: Fixed
• Fix Version/s: 1.0.0
• Component/s: Rust
• Labels: pull-request-available
• External issue URL: https://github.com/apache/arrow/issues/24686
• Assignee: Raphael Taylor-Davies
• Reporter: Raphael Taylor-Davies
• Created: 19/Apr/20 13:02
• Updated: 11/Jan/23 08:00
• Resolved: 24/Apr/20 01:34

Description

BufferBuilder<BooleanType>::append_slice is called by PrimitiveBuilder::append_slice with a constructed vector of true values.

Even in release builds the associated allocations and iterations are not optimised out, resulting in a third of the time to parse a parquet file containing single integers being spent in PrimitiveBuilder::append_slice.

This PR adds an append_n method to the BufferBuilderTrait that allows this to be handled more efficiently. My rather unscientific testing shows it to halve the amount of time spent in this method yielding an ~20% speedup for my particular workload.

 

Issue Links

• links to: GitHub Pull Request #6980