serkan-ozal's 3rd submission with some minor improvements

[serkan-ozal]

• faster merge by ignoring empty entries in the map
• enable CDS for faster startup (added prepare_serkan-ozal.sh to generate CDS archive in advance)
• some tweaks with JVM options
• optimized result printing

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): 604

• Execution time: 3.4s (It was 3.6s in the 2nd submission in my testing env)

• Execution time of reference implementation: 5m 54.1s

[serkan-ozal]

Hi @gunnarmorling,

I have sent my 3rd submission. Even though I don't see performance improvement in my testing env, it still might perform better in the eval machine as there are some major changes. Let's see how it will be in the eval machine.

Thanks in advance.

[gunnarmorling]

Yepp, slower indeed:

Benchmark 1: timeout -v 300 ./calculate_average_serkan-ozal.sh 2>&1
  Time (mean ± σ):      2.648 s ±  0.041 s    [User: 0.003 s, System: 0.006 s]
  Range (min … max):    2.605 s …  2.710 s    5 runs

Summary
  serkan-ozal: trimmed mean 2.6423087684, raw times 2.6048885754,2.7095721204000003,2.6545993044,2.6181676104,2.6541593904000003

Leaderboard
grep: ./src/main/java*/dev/morling/onebrc/CalculateAverage_serkan-ozal.java: No such file or directory

| # | Result (m:s.ms) | Implementation     | JDK | Submitter     | Notes     |
|---|-----------------|--------------------|-----|---------------|-----------|
|   | 00:02.642 | [link](https://github.com/gunnarmorling/1brc/blob/main/src/main/java/dev/morling/onebrc/CalculateAverage_serkan-ozal.java)| 21.0.1-open | [Serkan ÖZAL](https://github.com/serkan-ozal) |  |

[serkan-ozal]

Hi @gunnarmorling,

I have updated the optimizations:

• faster merge by ignoring empty entries in the map
• enable CDS for faster startup (added prepare_serkan-ozal.sh to generate CDS archive in advance)
• some tweaks with JVM options
• optimized result printing

In my testing environment, it has improved the performance by 200 ms. Will see how much it will be in the eval machine.

Could you please rerun it?

[gunnarmorling]

Yepp, makes for small improvement: 00:02.440 now.