[SPARK-46581] AccumulatorV2 isZero doesn't do what its name implies

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 3.5.0
• Fix Version/s: 4.0.0
• Component/s: Spark Core
• Labels: pull-request-available
• Assignee: Davin Tjong
• Reporter: Davin Tjong
• Created: 03/Jan/24 23:32
• Updated: 08/Jan/24 09:22
• Resolved: 08/Jan/24 09:22

Description

`AccumulatorV2`'s `isZero` doesn't do what the name or comment implies - it actually checks if the accumulator hasn't been updated.

The comment implies that for a `LongAccumulator`, for example, a value of `0` would cause `isZero` to be `true`. But if we were to `add(0)`, then the value would still be `0` but `isZero` would return `false`.

Propose to rename this to `isUpdated` so the name matches the meaning more closely.

Issue Links

• links to: GitHub Pull Request #44583