Are there any microbenchmarks to check the performance impact against enabled the `StrictNullChecks` feature?

[ryszardmakuch]

I am considering enabling the StrictNullChecks feature in production. However, In the Javadoc I can see following statement:

Enabling it protects against this but has significant performance impact.

jackson-module-kotlin/src/main/kotlin/com/fasterxml/jackson/module/kotlin/KotlinFeature.kt

Lines 38 to 45 in 11bfe2f

	/**
	* This feature represents whether to check deserialized collections.
	*
	* With this disabled, the default, collections which are typed to disallow null members (e.g. `List<String>`)
	* may contain null values after deserialization.
	* Enabling it protects against this but has significant performance impact.
	*/
	StrictNullChecks(enabledByDefault = false);

Are there any benchmarks to check the performance against the enabled and disabled feature? If not, would you like me to contribute the microbenchmark suite by creating a dedicated pull request?

I found that @k163377 used jmh to give you some numbers to prove significant improvement in deserialization speed #439 but those tests are not part of the jackson-module-kotlin project.

[k163377]

The following benchmark was created for verification with jackson-module-kogera.
The content is to deserialize Array, List and Map into wrapper types with one argument each.
https://github.com/ProjectMapK/kogera-benchmark/blob/master/src/jmh/kotlin/org/wrongwrong/extra/deser/StrictNullChecks.kt

The results with jackson-module-kotlin are as follows(higher is better)

Benchmark                                           Mode  Cnt        Score         Error  Units
o.w.extra.deser.StrictNullChecks.array             thrpt    4   788631.252 ±   56981.231  ops/s
o.w.extra.deser.StrictNullChecks.arrayStrict       thrpt    4   665656.537 ±   33375.375  ops/s
o.w.extra.deser.StrictNullChecks.list              thrpt    4   844107.697 ±   53169.624  ops/s
o.w.extra.deser.StrictNullChecks.listStrict        thrpt    4   687755.266 ±   60128.550  ops/s
o.w.extra.deser.StrictNullChecks.map               thrpt    4   752715.970 ±   29195.905  ops/s
o.w.extra.deser.StrictNullChecks.mapStrict         thrpt    4   585182.025 ±   13587.045  ops/s

We can see a clear performance degradation even with only one argument deserialization.
Also, since the StrictNullChecks option checks all arguments regardless of type, if there is more arguments, the bigger the performance loss.

---

By the way, I found a way to significant improve the performance of strictNullChecks and I will share it.
ProjectMapK/jackson-module-kogera#44

[k163377]

It is closed as a duplicate of #390.

[k163377]

It may be too late to confirm the impact on overall performance, but we have done so and will share it with you.
As a conclusion, the performance impact to anything other than Collection deserialization did not seem to be that significant.
https://github.com/ProjectMapK/kogera-benchmark#comparison-of-strictnullchecks