Package org.apache.storm.state

Interface StateProvider

All Known Implementing Classes:

InMemoryKeyValueStateProvider, RedisKeyValueStateProvider

public interface StateProvider

Used by the StateFactory to create a new state instances.

Method Summary

Modifier and Type	Method	Description
State	newState(String namespace, Map<String,Object> topoConf, TopologyContext context)	Returns a new state instance.

Method Details

newState

State newState(String namespace,
 Map<String,Object> topoConf,
 TopologyContext context)

Returns a new state instance. Each state belongs unique namespace which is typically the componentid-task of the task, so that each task can have its own unique state.

Parameters:

namespace - a namespace of the state

topoConf - the storm topology configuration

context - the TopologyContext

Returns:

a previously saved state if one exists otherwise a newly initialized state.