[DRAFT] Serializers cache

[qwwdfsad]

Attempt to somehow address #2003

[qwwdfsad]

Preliminary data

Benchmark                                Mode  Cnt   Score   Error   Units
LookupOverheadBenchmark.dataPlain       thrpt   14   9.831 ± 0.457  ops/us
LookupOverheadBenchmark.dataReified     thrpt   14   3.326 ± 0.084  ops/us
LookupOverheadBenchmark.genericPlain    thrpt   14   5.473 ± 0.565  ops/us
LookupOverheadBenchmark.genericReified  thrpt   14   0.164 ± 0.008  ops/us
LookupOverheadBenchmark.objectPlain     thrpt   14  27.828 ± 2.141  ops/us
LookupOverheadBenchmark.objectReified   thrpt   14   5.221 ± 0.101  ops/us

[qwwdfsad]

The following best-case approximation of caching:

@Benchmark                                                             
fun objectApprox(): Object {                                           
    typeOf<Object>()                                                   
    return Json.decodeFromString(Object.serializer(), "{}")            
}                                                                      

gives

LookupOverheadBenchmark.objectApprox  thrpt   14  13.181 ± 0.821  ops/us

which is much better for the benchmark that stresses empty string

[qwwdfsad]

Continuing in https://github.com/Kotlin/kotlinx.serialization/issues/2003

[LouisCAD]

Continuing a PR in an issue that predates it? Are you sure you referenced the right one?

[qwwdfsad]

Oh, right, I've meant https://github.com/Kotlin/kotlinx.serialization/pull/2015 :)