Package io.github.kaststream.api.v2

Interface Mapper

All Superinterfaces:

Serializable

public interface Mapper
extends Serializable

The map function.

Method Summary

Modifier and Type	Method	Description
default void	close()	Tear-down method for the user code.
org.apache.avro.Schema	getProducedType(org.apache.avro.Schema schema)	Declare the data type information of the data produced by your function.
KastRow	map(KastRow kRow, KastRowBuilder kastRowBuilder)	Your function implementation.
default void	open(Map<String,String> configuration, org.apache.avro.Schema schema)	Initialization method for the function.
default void	open(Map<String,String> configuration, org.apache.avro.Schema schema, Map<String,Object> meta)	Initialization method for the function.

Method Detail

map

KastRow map(KastRow kRow,
            KastRowBuilder kastRowBuilder)
     throws Exception

Your function implementation. Do what you need on the received rows.

Parameters:

kRow - the received row

Returns:

the transformed row

Throws:

Exception - in case of problem. This will stop your dag.

getProducedType

org.apache.avro.Schema getProducedType(org.apache.avro.Schema schema)

Declare the data type information of the data produced by your function.

Parameters:

schema - the input row schema

Returns:

the produced data typeInfo

open

default void open(Map<String,String> configuration,
                  org.apache.avro.Schema schema)
           throws Exception

Initialization method for the function.

Parameters:

configuration - The configuration containing the parameters attached to the contract

schema - the input row schema

Throws:

Exception - The function may throw exceptions which cause the streaming program to fail and go into recovery.

open

default void open(Map<String,String> configuration,
                  org.apache.avro.Schema schema,
                  Map<String,Object> meta)
           throws Exception

Initialization method for the function.

Parameters:

configuration - The configuration containing the parameters attached to the contract

schema - the input row schema

meta - the udf configuration parameters

Throws:

Exception - The function may throw exceptions which cause the streaming program to fail and go into recovery.

close

default void close()
            throws Exception

Tear-down method for the user code. It is called after the last call to the main working methods. For functions that are part of an iteration, this method will be invoked after each iteration superstep.

This method can be used for clean up work.

Throws:

Exception - The function may throw exceptions which cause the streaming program to fail and go into recovery.