Further de-ByteBuffer:ing of these classes is to be done, but this is the smallest most urgently needed benefit.
This commit is a WIP but in a fully working state, pushing due to the importance of the changes to offer lifecycle control over mmaps.
... also move some common configuration into the root build.gradle-file.
Support for JDK21 in lombok is a bit sketchy at the moment, but it seems to work. This upgrade is kind of important as the new index construction really benefits from Arena based lifecycle control over off-heap memory.
This is a big performance boost in array.range().get().
Without an override, each access will go through pages[page].get(...) for each get()-operation. This adds up very quickly. BTreeReader does a bunch of get():s on a range()'d array during traversal in the queryData... methods.
This is a system-wide change. The index used to have a lexicon, mapping words to wordIds using a large in-memory hash table. This made index-construction easier, but it
also added a fairly significant RAM penalty to both the index service and the loader.
The new design moves to 64 bit word identifiers calculated using the murmur hash of the keyword, and an index construction based on merging smaller indices.
It also became necessary half-way through to upgrade guice as its error reporting wasn't *quite* compatible with JDK20.
* Utilities for merging BTrees of entity size 1 and 2.
* Isolate and clean up sorting algorithms.
* Functions for keeping distinct items in a LongArray
