[LUCENE-9059] Reduce garbage created by ByteBuffersDataOutput

• Type: Improvement
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Fix Version/s: 8.4
• Lucene Fields: New
• Assignee: Unassigned
• Reporter: Adrien Grand
• Created: 22/Nov/19 18:45
• Updated: 28/Aug/22 15:53
• Resolved: 26/Nov/19 13:07

Description

When profiling indexing because of LUCENE-9027, I noticed that indexing produces a lot of unnecessary garbage because of ByteBuffersDataOutput, which can easily get fixed:

• reset() is implemented using streams, which apparently create lots of objects
• copyTo has an optimization for the case that ByteBuffers are backed by an array that never gets used because toBufferList makes the buffers read-only, which in-turn disallows access to the array

Issue Links

• links to: GitHub Pull Request #1031