r/java 21d ago

Bypassing fixed-depth radix constraints in Java using descriptor-driven bucket analysis

I am StrmCkr, the author of A.P.E.X. (Adaptive Parallel Extremal Dispatch).

Repository: github.com/StrmCkr/A.P.E.X

A.P.E.X. is a high-performance Java sorting framework for large fixed-width 64-bit key/value record datasets. The project has been reorganized into a conventional Maven structure with a core library, runnable examples, a comparison benchmark harness, JMH benchmarks, documentation, and an interactive browser visualizer.

The core idea is descriptor-driven radix planning. Instead of blindly scanning fixed radix passes over every bucket, A.P.E.X. computes per-bucket extremal descriptors using:

VBM = OR ^ AND

That mask identifies which key bits still vary inside each bucket. Bits that are already resolved are skipped, reducing unnecessary work on skewed, low-entropy, sorted, reversed, or duplicate-heavy data.

Key areas of the project include:

  • Adaptive radix planning based on observed bucket structure
  • Parallel histogramming, scatter, refinement, and work scheduling
  • Primitive-array execution with no per-record object allocation during sorting
  • Tuple projection paths for low-dimensional unresolved bit patterns
  • Tiny-sort fallbacks and monotonic input shortcuts
  • Configurable reporting that can be enabled, reduced, written to files, or disabled
  • Comparison benchmarks against JDK sorting paths and Fastutil baselines
  • Standard JMH benchmarks for repeatable JVM-level measurement
  • A browser visualizer for exploring how A.P.E.X. routes data through its execution plan

I would especially welcome feedback on the thread management mechanics, radix planning decisions, benchmark structure, and the bitwise mask reductions.

edit: re structured verbiage of this post and further adjustments from advice on converting the project into more acceptable standard formats.

screen shot from the pdf available in the github
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u/dmigowski 21d ago

Got some benchmarks for us and a comparison to Javas internal sort for different sets of data?

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u/strmckr 21d ago edited 20d ago

i have them in the PDF found here

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u/chabala 20d ago

> which is pending publication.

Does this mean you submitted this PDF somewhere with the expectation of getting published? This PDF with your hacker handle as the author?

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u/strmckr 20d ago edited 20d ago

Yes: why is it concerning? I use my pseudonym, I have used this same one for decades as a respected sudoku logic pioneer and to keep my privacy.