improve hard disk access locality, another 8%

[abeobk]

Check List:

• [x] Tests pass (./test.sh <username> shows no differences between expected and actual outputs)
• [x] All formatting changes by the build are committed
• [x] Your launch script is named calculate_average_<username>.sh (make sure to match casing of your GH user name) and is executable
• [x] Output matches that of calculate_average_baseline.sh
• [x] For new entries, or after substantial changes: When implementing custom hash structures, please point to where you deal with hash collisions (line number)

Last version: Benchmark 1: ./calculate_average_abeobk.sh Time (mean ± σ): 611.7 ms ± 10.8 ms [User: 1.6 ms, System: 6.3 ms] Range (min … max): 597.6 ms … 638.7 ms 10 runs

This version: Benchmark 1: ./calculate_average_abeobk.sh Time (mean ± σ): 561.8 ms ± 6.6 ms [User: 2.1 ms, System: 1.7 ms] Range (min … max): 544.4 ms … 569.8 ms 10 runs

This runs faster on my machine, but I'm not sure if it will have the same performance on the evaluation one. This version processes data in small chunks, each 4MB in size, thereby improving hard disk access locality.

[gunnarmorling]

Nice, a tad faster:

Benchmark 1: timeout -v 300 ./calculate_average_abeobk.sh 2>&1
  Time (mean ± σ):      2.146 s ±  0.005 s    [User: 0.002 s, System: 0.004 s]
  Range (min … max):    2.136 s …  2.155 s    10 runs

Summary
  abeobk: trimmed mean 2.1465672555650004, raw times 2.13622836594,2.1448431559400003,2.14909065494,2.1479434199400003,2.14607579794,2.1437134649400003,2.1473469029400003,2.14786259294,2.1456620549400003,2.1554339599400003

Leaderboard

| # | Result (m:s.ms) | Implementation     | JDK | Submitter     | Notes     |
|---|-----------------|--------------------|-----|---------------|-----------|
|   | 00:02.146 | [link](https://github.com/gunnarmorling/1brc/blob/main/src/main/java/dev/morling/onebrc/CalculateAverage_abeobk.java)| 21.0.2-graal | [Van Phu DO](https://github.com/abeobk) | GraalVM native binary, uses Unsafe |