[ARROW-16983] Delta byte array encoder broken due to memory leak

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 9.0.0
• Component/s: Go, Parquet
• Labels: pull-request-available
• External issue URL: https://github.com/apache/arrow/issues/32298
• Assignee: Unassigned
• Reporter: Matt DePero
• Created: 05/Jul/22 22:39
• Updated: 11/Jan/23 11:47
• Resolved: 06/Jul/22 20:30

Description

The `DeltaByteArrayEncoder` has a memory leak due to a bug in how `EstimatedDataEncodedSize` is calculated. DeltaByteArrayEncoder extends `encoder` which calculates EstimatedDataEncodedSize by calling `Len()` on its `PooledBufferWriter` sink. DeltaByteArrayEncoder however does not write data to sink, instead writing data to `prefixEncoder` and `suffixEncoder` causing EstimatedDataEncodedSize to always return zero. 

Issue Links

• links to: GitHub Pull Request #13522