[ARROW-8629] [Rust] Eliminate indirection of ZST allocations

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 0.17.0
• Fix Version/s: 1.0.0
• Component/s: Rust
• Labels: pull-request-available
• External issue URL: https://github.com/apache/arrow/issues/24791
• Assignee: Mahmut Bulut
• Reporter: Mahmut Bulut
• Created: 29/Apr/20 17:55
• Updated: 11/Jan/23 08:01
• Resolved: 19/May/20 23:29

Description

Currently, no matter what any array construction without data creates 0 sized layouts and passes itself to Rust's allocator API, thus OS then comes back to the program and does the job.

This issue is two-fold:

• First, this creates indirection and UB in a sense.
• Second, degrades the performance for the merging simd, merging arrays, constructing arrays etc. and intermediate arrays when doing ops. over them.

The solution would be:

• Having UB solved without a performance downside.
• Improve the performance

Issue Links

• links to: GitHub Pull Request #7061