org.apache.whirr.state
Class ClusterStateStore

java.lang.Object
  org.apache.whirr.state.ClusterStateStore

Direct Known Subclasses:

BlobClusterStateStore, FileClusterStateStore, MemoryClusterStateStore

public abstract class ClusterStateStore
extends Object

Interface for cluster state storage facilities.

Constructor Summary

ClusterStateStore()

Method Summary

abstract void	destroy() Destroys the provided cluster's state in storage.
abstract Cluster	load() Deserializes cluster state from storage.
abstract void	save(Cluster cluster) Saves cluster state to storage.
protected String	serialize(Cluster cluster) Create parser friendly string representation for a Cluster
Cluster	tryLoadOrEmpty() Try to load the cluster state or return an empty instance
protected Cluster	unserialize(ClusterSpec spec, String content) Rebuild the Cluster instance by using the string representation

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

ClusterStateStore

public ClusterStateStore()

Method Detail

load

public abstract Cluster load()
                      throws IOException

Deserializes cluster state from storage.

Returns:

Throws:

IOException

tryLoadOrEmpty

public Cluster tryLoadOrEmpty()

Try to load the cluster state or return an empty instance

Returns:

save

public abstract void save(Cluster cluster)
                   throws IOException

Saves cluster state to storage.

Parameters:

cluster -

Throws:

IOException

destroy

public abstract void destroy()
                      throws IOException

Destroys the provided cluster's state in storage.

Throws:

IOException

serialize

protected String serialize(Cluster cluster)
                    throws IOException

Create parser friendly string representation for a Cluster

Parameters:

cluster -

Returns:

String representation

Throws:

IOException

unserialize

protected Cluster unserialize(ClusterSpec spec,
                              String content)
                       throws UnknownHostException

Rebuild the Cluster instance by using the string representation

Parameters:

spec -

content -

Returns:

Throws:

UnknownHostException