On Sun, 21 Nov 2021 00:29:46 GMT, Vicente Romero <vrom...@openjdk.org> wrote:
>> Please review this PR which aims to optimize the implementation of the
>> `toString` method we provide for records. A benchmark comparing the
>> implementation we are providing for records with lombok found out that
>> lombok is much faster mainly because our implementation uses
>> `String::format`. This fix is basically delegating on
>> StringConcatFactory::makeConcatWithConstants which is faster.
>>
>> TIA
>>
>> This is the result of the benchmark comparing records to lombok with vanilla
>> JDK:
>>
>> Benchmark Mode Cnt Score Error Units
>> MyBenchmark.base avgt 4 0.849 ± 0.111 ns/op
>> MyBenchmark.equals_record avgt 4 7.343 ± 2.740 ns/op
>> MyBenchmark.equals_value avgt 4 6.644 ± 1.920 ns/op
>> MyBenchmark.record_hash_code avgt 4 5.763 ± 3.882 ns/op
>> MyBenchmark.record_to_string avgt 4 262.626 ± 12.574 ns/op
>> <------ Before
>> MyBenchmark.value_class_to_string avgt 4 30.325 ± 21.389 ns/op
>> MyBenchmark.value_hash_code avgt 4 5.048 ± 3.936 ns/op
>>
>>
>> after this patch:
>>
>> Benchmark Mode Cnt Score Error Units
>> MyBenchmark.base avgt 4 0.680 ± 0.185 ns/op
>> MyBenchmark.equals_record avgt 4 5.599 ± 1.348 ns/op
>> MyBenchmark.equals_value avgt 4 5.718 ± 4.633 ns/op
>> MyBenchmark.record_hash_code avgt 4 4.628 ± 4.368 ns/op
>> MyBenchmark.record_to_string avgt 4 26.791 ± 1.817 ns/op
>> <------- After
>> MyBenchmark.value_class_to_string avgt 4 35.473 ± 2.626 ns/op
>> MyBenchmark.value_hash_code avgt 4 6.152 ± 5.101 ns/op
>
> Vicente Romero has updated the pull request incrementally with one additional
> commit since the last revision:
>
> setting max split size to 20
Marked as reviewed by redestad (Reviewer).
src/java.base/share/classes/java/lang/runtime/ObjectMethods.java line 276:
> 274: int namesIndex = 0;
> 275: do {
> 276: /* StringConcatFactory::makeConcatWithConstants can only
> deal with 200 spots, longs and double occupy two
typos: spot -> slot, chunck -> chunk, diference -> difference
src/java.base/share/classes/java/lang/runtime/ObjectMethods.java line 314:
> 312: ).getTarget();
> 313: mhs[splitIndex] =
> MethodHandles.filterArguments(mhs[splitIndex], 0, currentSplitGetters);
> 314: mhs[splitIndex] = MethodHandles.permuteArguments(
This is some gnarly logic. Could we add some comments on what permuteArguments
with a reorder array of just zeros is doing here?
src/java.base/share/classes/java/lang/runtime/ObjectMethods.java line 330:
> 328:
> 329: /**
> 330: * Chops the getters into smaller chunks according to the maximum
> number of spots
typo: spots -> slots
src/java.base/share/classes/java/lang/runtime/ObjectMethods.java line 333:
> 331: * StringConcatFactory::makeConcatWithConstants can chew
> 332: * @param getters the current getters
> 333: * @return chunks that wont surpass the maximum number of spots
> StringConcatFactory::makeConcatWithConstants can chew
ditto
-------------
PR: https://git.openjdk.java.net/jdk/pull/6403
