[ARROW-7681] [Rust] Explicitly seeking a BufReader will discard the internal buffer

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 1.0.0
• Component/s: Rust
• Labels: pull-request-available
• External issue URL: https://github.com/apache/arrow/issues/23926
• Assignee: Unassigned
• Reporter: Max Burke
• Created: 26/Jan/20 00:05
• Updated: 11/Jan/23 07:55
• Resolved: 27/Apr/20 17:04

Description

This behavior was observed in the Parquet Rust file reader (parquet/src/util/io.rs).

 

Pull request: https://github.com/apache/arrow/pull/6280

 

From the Rust documentation for BufReader:

 

"Seeking always discards the internal buffer, even if the seek position would otherwise fall within it. This guarantees that calling .into_inner() immediately after a seek yields the underlying reader at the same position."

 

https://doc.rust-lang.org/std/io/struct.BufReader.html#impl-Seek

Issue Links

• fixes: ARROW-7574 [Rust] FileSource read implementation is seeking for each single byte
• links to: GitHub Pull Request #6280
• links to: GitHub Pull Request #6949