org.planx.xmlstore.stores
Class DistributedXMLStore

java.lang.Object
  org.planx.xmlstore.stores.AbstractXMLStore
      org.planx.xmlstore.stores.DistributedXMLStore

All Implemented Interfaces:

XMLStore

public class DistributedXMLStore
extends AbstractXMLStore

A peer-to-peer XMLStore that uses Kademlia as routing module. It only operates on location independent ValueReferences. If an XMLStore that does not operate on ValueReferences is used as the underlying XMLStore (e.g. LocalXMLStore), it must be wrapped in a TranslatorXMLStore.

Author:

Thomas Ambus

Field Summary

Fields inherited from class org.planx.xmlstore.stores.AbstractXMLStore

xmlstore

Constructor Summary

DistributedXMLStore(XMLStore xmlstore, int udpPort, int tcpPort, InetSocketAddress bootstrap)
Creates a DistributedXMLStore which listens for routing requests on the specified UDP port and listens for data transfer requests on the specified TCP port.

Method Summary

void	close() The method is used to let the XMLStore properly commit all data to the underlying ressource, release resources, and so forth.
NameServer	getNameServer() Returns a GlobalNameServer that uses the same DistributedMap as this DistributedXMLStore.
protected Node	resolvedLoad(Reference vref) If the Reference is not known in the underlying XMLStore it is looked up in the network and loaded from another peer if it exists.
Reference	save(Node node) Always saves locally even if the node might already be stored elsewhere in the network.

Methods inherited from class org.planx.xmlstore.stores.AbstractXMLStore

checkClosed, load, toString

Methods inherited from class java.lang.Object

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

Constructor Detail

DistributedXMLStore

public DistributedXMLStore(XMLStore xmlstore,
                           int udpPort,
                           int tcpPort,
                           InetSocketAddress bootstrap)
                    throws IOException

Creates a DistributedXMLStore which listens for routing requests on the specified UDP port and listens for data transfer requests on the specified TCP port. The XML Store is bootstraped to an existing XML Store network by specifying a bootstrap IP and UDP port. If the bootstrap IP is null the XML Store will not attempt to connect to an existing network. The DistributedXMLStore only saves locally.

Parameters:

xmlstore - The underlying XMLStore.

udpPort - UDP port on which to listen for routing requests

tcpPort - TCP port on which to listen for data transfer requests

bootstrap - IP and UDP port of an existing peer in the network

Throws:

IOException

Method Detail

getNameServer

public NameServer getNameServer()

Returns a GlobalNameServer that uses the same DistributedMap as this DistributedXMLStore.

close

public void close()
           throws IOException

Description copied from interface: XMLStore

The method is used to let the XMLStore properly commit all data to the underlying ressource, release resources, and so forth. Once close has been issued on an XMLStore, the store is no longer available for handling requests. Any subsequent request to the store will result in an exception being thrown. An XMLStore implementation has to ensure that this happens.

Specified by:

close in interface XMLStore

Overrides:

close in class AbstractXMLStore

Throws:

IOException - if it is not possible to properly close the store

save

public Reference save(Node node)
               throws IOException

Always saves locally even if the node might already be stored elsewhere in the network. This is because it is considered very likely that the node will be loaded locally later.

Specified by:

save in interface XMLStore

Overrides:

save in class AbstractXMLStore

Parameters:

node - representing XML data in the form of semi-structured tree data

Returns:

a reference to the saved node/tree

Throws:

IOException - if an error occurs during disk, network, etc access

resolvedLoad

protected Node resolvedLoad(Reference vref)
                     throws IOException,
                            UnknownReferenceException

If the Reference is not known in the underlying XMLStore it is looked up in the network and loaded from another peer if it exists. If the Reference could not be found an UnknownReferenceException is thrown.

Overrides:

resolvedLoad in class AbstractXMLStore

Parameters:

vref - the resolved Reference

Throws:

IOException

UnknownReferenceException