[CASSANDRA-9473] Introduce BTreeSet with support for in-place reversal

• Type: Improvement
• Status: Resolved
• Priority: Low
• Resolution: Duplicate
• Assignee: Paulo Motta
• Reporter: Benedict Elliott Smith

Authors

Paulo Motta

• Created: 25/May/15 08:23
• Updated: 16/Apr/19 09:31
• Resolved: 01/Jul/15 18:03

Description

Follow up to CASSANDRA-8099.

We use TreeSet in a lot of places unnecessarily. This is especially a concern now that we store the set of rows we're searching for in both forward and (potentially) reverse order, which we have to construct twice. A very simple wrapper around BTree (which we had previously, but did not employ) would permit us to reverse this collection without any extra work, can be built more cheaply, consumes less memory, and supports the SearchIterator interface, so can be iterated more efficiently.

Issue Links

• depends upon: CASSANDRA-8099 Refactor and modernize the storage engine