[SPARK-30012] Change classes extending scala collection classes to work with 2.13

• Type: Sub-task
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 3.0.0
• Fix Version/s: 3.0.0
• Component/s: Spark Core, SQL
• Assignee: Sean R. Owen
• Reporter: Sean R. Owen
• Created: 24/Nov/19 22:10
• Updated: 03/Dec/19 17:04
• Resolved: 03/Dec/19 17:00

Description

Several classes in the code base extend Scala collection classes, like:

• ExternalAppendOnlyMap
• CaseInsensitiveMap
• AttributeMap
• (probably more I haven't gotten to yet)

The collection hierarchy changed in 2.13, and like elsewhere, I don't see that it's possible to use a compat library or clever coding to bridge the difference. I think we need to maintain two implementations in parallel source trees, possibly with a common ancestor with the commonalities.

Issue Links

• links to: GitHub Pull Request #26728