[ARROW-8744] [Rust] ParquetIterator's next method should be safe to call even after reached end of iteration

• Type: Improvement
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Fix Version/s: 1.0.0
• Component/s: Rust - DataFusion
• Labels: pull-request-available
• External issue URL: https://github.com/apache/arrow/issues/24896
• Assignee: QP Hou
• Reporter: QP Hou
• Created: 09/May/20 05:10
• Updated: 11/Jan/23 08:02
• Resolved: 18/May/20 23:27

Description

Once reached end of iteration, calling next on ParquetIterator will result in an error. This is inconvenient in two ways:

• when shared between multiple threads, only one of the thread will be able to terminate without error
• sender for response_rx cannot terminate the iteration early and free up resources, instead, it needs to always wait for signal from request_tx before closing up the connection

Issue Links

• links to: GitHub Pull Request #7133