[LUCENE-10130] HnswGraph could make use of a SparseFixedBitSet.getAndSet

• Type: Task
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 9.0
• Labels: vector-based-search
• Lucene Fields: New
• Assignee: Unassigned
• Reporter: Robert Muir
• Created: 28/Sep/21 14:47
• Updated: 28/Aug/22 16:26
• Resolved: 02/Oct/21 12:33

Description

Currently HnswGraph uses SparseFixedBitSet "visited" to track where it has already been. The logic currently looks like this:

if (visited.get(entryPoint) == false) {
  visited.set(entryPoint);
  ... logic ...
}

If SparseFixedBitSet had a getAndSet (like FixedBitSet), the code could be:

if (visited.getAndSet(entrypoint) == false) {
  ... logic ...
}