uk.ac.ic.doc.automed.p2p.protocol
Class QEP

java.lang.Object
  uk.ac.ic.doc.automed.p2p.protocol.QEP

public class QEP
extends java.lang.Object

Field Summary

private AutoMedPeer	_mainPeer
private ObjectCache	_qcache
private static QEP	_qep
private java.util.concurrent.ExecutorService	brokerService

Constructor Summary

private

QEP(AutoMedPeer mainPeer) Creates a new instance of QEP

Method Summary

private void	cacheQuery(java.lang.String msgID, java.lang.String qID)
static java.util.Properties	convertQiToCommProps(java.util.Properties props, RuntimeParameters params) Convert selected quality indicator parameters into communication properties
AbstractMessage	executeQuery(AbstractMessage request) Execute query and return result (server-side).
java.util.Map	executeQuery(java.lang.String query, java.lang.String schema, QueryProcessorConfiguration qpc) This method should be used as the first invocation by the user application. It is a controller method in that it reads the application parameters to decide a suitable course of action for the query.
AbstractMessage	executeQuery(java.lang.String query, java.lang.String schema, QueryProcessorConfiguration qpc, PeerProcessDescription destPeer) Send a query to the network for execution (client-side).
static QEP	getQEPInstance(AutoMedPeer mainPeer) Return a single QEP instance per JVM
private boolean	isInCache(java.lang.String msgID, java.lang.String qID)
private void	registerPeerHandlers() Peer: Register message handlers on the peer
protected AbstractMessage	sendGroupQuery(AbstractMessage request, java.lang.String query, java.lang.String schema, RuntimeParameters params, java.util.Collection brokerPeers) Send a query to a set of peers
private AbstractMessage	sendQuery(AbstractMessage request, java.lang.String query, java.lang.String schema, RuntimeParameters params, PeerProcessDescription destPeer) Process a query message and forward it on to the next target peer.

Methods inherited from class java.lang.Object

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

Field Detail

_qep

private static QEP _qep

_mainPeer

private AutoMedPeer _mainPeer

brokerService

private java.util.concurrent.ExecutorService brokerService

_qcache

private ObjectCache _qcache

Constructor Detail

QEP

private QEP(AutoMedPeer mainPeer)

Creates a new instance of QEP

Method Detail

getQEPInstance

public static QEP getQEPInstance(AutoMedPeer mainPeer)

Return a single QEP instance per JVM

sendGroupQuery

protected AbstractMessage sendGroupQuery(AbstractMessage request,
                                         java.lang.String query,
                                         java.lang.String schema,
                                         RuntimeParameters params,
                                         java.util.Collection brokerPeers)
                                  throws CommunicationException,
                                         AutoMedException

Send a query to a set of peers

Parameters:

queryDesc -

destPeer -

Returns:

Throws:

CommunicationException

AutoMedException

sendQuery

private AbstractMessage sendQuery(AbstractMessage request,
                                  java.lang.String query,
                                  java.lang.String schema,
                                  RuntimeParameters params,
                                  PeerProcessDescription destPeer)
                           throws CommunicationException,
                                  AutoMedException

Process a query message and forward it on to the next target peer.

Parameters:

request -

query -

schema -

params -

destPeer -

Returns:

Throws:

CommunicationException

AutoMedException

executeQuery

public AbstractMessage executeQuery(java.lang.String query,
                                    java.lang.String schema,
                                    QueryProcessorConfiguration qpc,
                                    PeerProcessDescription destPeer)
                             throws CommunicationException,
                                    AutoMedException

Send a query to the network for execution (client-side).
This method is used by the application to invoke the process of executing a query message over a specific target peer.

Parameters:

qpc - a QueryProcessorConfiguration object of the query to be sent

destPeer - a PeerProcessDescription object of the destination peer to which the query is sent

Returns:

AbstractMessage result of query execution

Throws:

CommunicationException

AutoMedException

convertQiToCommProps

public static java.util.Properties convertQiToCommProps(java.util.Properties props,
                                                        RuntimeParameters params)

Convert selected quality indicator parameters into communication properties

executeQuery

public java.util.Map executeQuery(java.lang.String query,
                                  java.lang.String schema,
                                  QueryProcessorConfiguration qpc)
                           throws CommunicationException,
                                  AutoMedException

This method should be used as the first invocation by the user application.
It is a controller method in that it reads the application parameters to decide a suitable course of action for the query.

Parameters:

query - the use query

schema - the public schema on which the query is to be evaluated

qpc - a query processor configuration object

targetPeers - a set of peers on which the query will be evaluated

Returns:

Map of peer to ASG result

Throws:

CommunicationException

AutoMedException

executeQuery

public AbstractMessage executeQuery(AbstractMessage request)

Execute query and return result (server-side). This method is invoked by intermediate peers as part of the query execution process.

Parameters:

request - AbstractMessage received from the network

Returns:

AbstractMessage the message to send back to client

cacheQuery

private void cacheQuery(java.lang.String msgID,
                        java.lang.String qID)

isInCache

private boolean isInCache(java.lang.String msgID,
                          java.lang.String qID)

registerPeerHandlers

private void registerPeerHandlers()

Peer: Register message handlers on the peer