Two optimizations:
1. Insert string bytes directly to remove decoding&encoding process.
2. Use native reader to read the hudi base file if it has no log file. Use `explain` to show how many splits are read natively.
hudi serializer `org.apache.hudi.common.util.SerializationUtils$KryoInstantiator.newKryo` throws error like `java.lang.IllegalArgumentException: classLoader cannot be null`. Set the default class loader for scan thread.
```
public Kryo newKryo() {
Kryo kryo = new Kryo();
...
// Thread.currentThread().getContextClassLoader() returns null
kryo.setClassLoader(Thread.currentThread().getContextClassLoader());
...
return kryo;
}
```
The java-udf module has become increasingly large and difficult to manage, making it inconvenient to package and use as needed. It needs to be split into multiple sub-modules, such as : java-commom、java-udf、jdbc-scanner、hudi-scanner、 paimon-scanner.
Co-authored-by: lexluo <lexluo@tencent.com>
