Roll back to JDK 21 for now, and make Java version configurable in the root build.gradle
The project has run into no less than three distinct show-stopping bugs in JDK22, across multiple vendors, and gradle still doesn't fully support it, meaning you need multiple JDK versions installed.
Seems to work, tests are green and initial testing finds no errors. Still a bit untested, committing WIP as-is because it would suck to lose weeks of work due to a drive failure or something.
Look, this will make the git history look funny, but trimming unnecessary depth from the source tree is a very necessary sanity-preserving measure when dealing with a super-modularized codebase like this one.
While it makes the project configuration a bit less conventional, it will save you several clicks every time you jump between modules. Which you'll do a lot, because it's *modul*ar. The src/main/java convention makes a lot of sense for a non-modular project though. This ain't that.
To avoid having to either hard-code or manually configure service addresses (possibly several dozen), and to reduce the project's dependency on docker to deal with routing and discovery, the option to use [Zookeeper](https://zookeeper.apache.org/) to manage services and discovery has been added.
A service registry interface was added, with a Zookeeper implementation and a basic implementation that only works on docker and hard-codes everything.
The last remaining REST service, the assistant-service, has been migrated to gRPC.
This also proved a good time to clear out primordial technical debt from the root of the codebase. The 'service-client' library has been taken behind the barn and given a last farewell. It's replaced by a small library for managing gRPC channels.
Since it's no longer used by anything, RxJava has been removed as a dependency from the project.
Although the current state seems reasonably stable, this is a work-in-progress commit.
This was caused by a bug in the binary search algorithm causing it to sometimes return positive values when encoding a search miss.
It was also necessary to get rid of the vestiges of the old LongArray and IntArray classes to make this fix doable.
* (index-reverse) Parallel construction of the reverse indexes.
* (array) Remove wasteful calculation of numDistinct before merging two sorted arrays.
* (index-reverse) Force changes to disk on close, reduce logging.
* (index-reverse) Clean up merging process and add back logging
* (run) Add a conservative default for INDEX_CONSTRUCTION_PROCESS_OPTS's parallelism as it eats a lot of RAM
* (index-reverse) Better logging during processing
* (array) 2GB+ compatible write() function
* (array) 2GB+ compatible write() function
* (index-reverse) We are logging like Bolsonaro and I will not have it.
* (reverse-index) Self-diagnostics
* (btree) Fix bug in btree reader to do with large data sizes
... 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.
* Utilities for merging BTrees of entity size 1 and 2.
* Isolate and clean up sorting algorithms.
* Functions for keeping distinct items in a LongArray
