io.ray.streaming.runtime.context

Interface ContextBackend

All Known Implementing Classes:

AtomicFsBackend, LocalFileContextBackend, MemoryContextBackend

public interface ContextBackend

This interface is used for storing context of JobWorker and JobMaster. The checkpoint returned by user function is also saved using this interface.

Method Summary

Modifier and Type	Method and Description
boolean	exists(String key) check if key exists in state
byte[]	get(String key) get content by key
void	put(String key, byte[] value) put content by key
void	remove(String key) remove content by key

Method Detail

exists

boolean exists(String key)
        throws Exception

check if key exists in state

Returns:

true if exists

Throws:

Exception

get

byte[] get(String key)
    throws Exception

get content by key

Parameters:

key - key

Returns:

the StateBackend

Throws:

Exception

put

void put(String key,
         byte[] value)
  throws Exception

put content by key

Parameters:

key - key

value - content

Throws:

Exception

remove

void remove(String key)
     throws Exception

remove content by key

Parameters:

key - key

Throws:

Exception