[Enhancement] Cache Schema instances for classes in a weak reference cache since creating an instance could be CPU intensive

[lhotari]

Search before asking

• I searched in the issues and found nothing similar.

Motivation

For example, Schema.AVRO(SomeClass.class) is fairly CPU intensive. It would be useful it there would be a weak reference cache for caching the schema instance.

Solution

• add a weak reference cache for caching a scheme instance for Schema.AVRO, Schema.JSON, Schema.PROTOBUF.
• Don't return the schema instance directly since schema instances are mutable. Instead return a clone of the cached instance.

Alternatives

Anything else?

Are you willing to submit a PR?

• I'm willing to submit a PR!

[walkinggo]

Are there any limitations in the specific technical framework for implementing weak references? How should we limit the size of the cache?