org.unict.ing.pds.dhtdb.datamanager

Class DataManagerChordSessionBean

java.lang.Object

org.unict.ing.pds.dhtdb.datamanager.DataManagerChordSessionBean

All Implemented Interfaces:

DataManagerChordSessionBeanLocal

public class DataManagerChordSessionBean
extends Object
implements DataManagerChordSessionBeanLocal

The bean responsible of the low-level communication with the Chord Overlay network

Field Summary

Fields

Modifier and Type	Field and Description
private javax.ejb.SessionContext	context
private FingerSessionBeanLocal	fingerSessionBean CONFIG VARS END
private static int	PERIOD CONFIG VARS

Constructor Summary

Constructors

Constructor and Description
DataManagerChordSessionBean()

Method Summary

Modifier and Type	Method and Description
NodeReference	findSuccessor(Key key) implementation of the findSuccessor Chord primitive using the FingerTable and a RemoteNodeProxy (the DataManager is just a client, not in the ring, as Chord protocol permits)
private void	fixFingers() Fix fingers Chord primitive implementation
private RemoteNodeProxy	getReference(NodeReference nodeReference) Get an instance of a RemoteNodeProxy for the NodeReference given
private void	init()
List<GenericValue>	lookup(Key key) Make a lookup on the Chord Network for the value associated with the given Key
void	timeout(javax.ejb.Timer timer)
Boolean	update(Key key, GenericValue elem)
Boolean	update(Key key, List<GenericValue> elems) Make a delete and put in the chord network (just for simplicity not in a single call to the proxy) for a List of elems
Boolean	write(Key key, GenericValue elem) Make a put in the Chord Network for the given elem
Boolean	write(Key key, List<GenericValue> elems) Make a put in the Chord Network for a full value (a List) associated with the Key

Methods inherited from class java.lang.Object

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

Field Detail

PERIOD

private static final int PERIOD

CONFIG VARS

See Also:

Constant Field Values

fingerSessionBean

private FingerSessionBeanLocal fingerSessionBean

CONFIG VARS END

context

private javax.ejb.SessionContext context

Constructor Detail

DataManagerChordSessionBean

public DataManagerChordSessionBean()

Method Detail

init

@PostConstruct
private void init()

timeout

public void timeout(javax.ejb.Timer timer)

lookup

public List<GenericValue> lookup(Key key)

Make a lookup on the Chord Network for the value associated with the given Key

Specified by:

lookup in interface DataManagerChordSessionBeanLocal

Parameters:

key - |

Returns:

| a List of the values associated with the given Key (see Light for motivations about a List, that we considers the real value stored in the Chord Network with a Key)

write

public Boolean write(Key key,
                     GenericValue elem)

Make a put in the Chord Network for the given elem

Specified by:

write in interface DataManagerChordSessionBeanLocal

Parameters:

key - |

elem - |

Returns:

| the result of the put

write

public Boolean write(Key key,
                     List<GenericValue> elems)

Make a put in the Chord Network for a full value (a List) associated with the Key

Specified by:

write in interface DataManagerChordSessionBeanLocal

Parameters:

key - |

elems - |

Returns:

| the result of the put

update

public Boolean update(Key key,
                      List<GenericValue> elems)

Make a delete and put in the chord network (just for simplicity not in a single call to the proxy) for a List of elems

Specified by:

update in interface DataManagerChordSessionBeanLocal

Parameters:

key - |

elems - |

Returns:

|

update

public Boolean update(Key key,
                      GenericValue elem)

Specified by:

update in interface DataManagerChordSessionBeanLocal

findSuccessor

public NodeReference findSuccessor(Key key)

implementation of the findSuccessor Chord primitive using the FingerTable and a RemoteNodeProxy (the DataManager is just a client, not in the ring, as Chord protocol permits)

Parameters:

key - |

Returns:

|

getReference

private RemoteNodeProxy getReference(NodeReference nodeReference)

Get an instance of a RemoteNodeProxy for the NodeReference given

Parameters:

nodeReference - |

Returns:

| RemoteNodeProxy

fixFingers

private void fixFingers()

Fix fingers Chord primitive implementation