/*
* Mojito Distributed Hash Table (Mojito DHT)
* Copyright (C) 2006-2007 LimeWire LLC
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
package org.limewire.mojito.handler.response;
import java.io.IOException;
import java.net.SocketAddress;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.Map;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.limewire.mojito.Context;
import org.limewire.mojito.EntityKey;
import org.limewire.mojito.KUID;
import org.limewire.mojito.db.DHTValueEntity;
import org.limewire.mojito.messages.FindNodeResponse;
import org.limewire.mojito.messages.FindValueResponse;
import org.limewire.mojito.messages.LookupRequest;
import org.limewire.mojito.messages.RequestMessage;
import org.limewire.mojito.messages.ResponseMessage;
import org.limewire.mojito.result.FindValueResult;
import org.limewire.mojito.routing.Contact;
import org.limewire.mojito.settings.LookupSettings;
import org.limewire.mojito.util.DatabaseUtils;
import org.limewire.security.SecurityToken;
/**
* Implements FIND_VALUE response specific features.
*/
public class FindValueResponseHandler extends LookupResponseHandler<FindValueResult> {
private static final Log LOG = LogFactory.getLog(FindValueResponseHandler.class);
/** Whether or not this is an exhaustive lookup. */
private boolean exchaustive = false;
/** The key we're looking for */
private final EntityKey lookupKey;
/** Collection of EntityKeys */
private final Collection<EntityKey> entityKeys
= new ArrayList<EntityKey>();
/** Collection of DHTValueEntities */
private final Collection<DHTValueEntity> entities
= new ArrayList<DHTValueEntity>();
public FindValueResponseHandler(Context context, EntityKey lookupKey) {
super(context, lookupKey.getPrimaryKey());
this.lookupKey = lookupKey;
setExhaustive(LookupSettings.EXHAUSTIVE_VALUE_LOOKUP.getValue());
}
@Override
protected void response(ResponseMessage message, long time) throws IOException {
super.response(message, time);
}
@Override
protected void timeout(KUID nodeId, SocketAddress dst, RequestMessage message, long time) throws IOException {
super.timeout(nodeId, dst, message, time);
}
@Override
protected boolean lookup(Contact node) throws IOException {
if (super.lookup(node)) {
return true;
}
return false;
}
/**
* Sets whether or not this is an exhaustive lookup
* (works only with FIND_VALUE lookups)
*/
public void setExhaustive(boolean exchaustive) {
this.exchaustive = exchaustive;
}
@Override
protected void finishLookup() {
long time = getElapsedTime();
int currentHop = getCurrentHop();
Map<Contact, SecurityToken> path = getPath();
Collection<DHTValueEntity> entities = getDHTValueEntities();
Collection<EntityKey> entityKeys = getEntityKeys();
setReturnValue(new FindValueResult(
lookupKey, path, entities, entityKeys, time, currentHop));
}
/**
* Returns the type of value we're looking for
*/
public EntityKey getLookupKey() {
return lookupKey;
}
/**
* Returns all DHTValueEntities that were found
*/
public Collection<DHTValueEntity> getDHTValueEntities() {
return entities;
}
/**
* Returns all EntityKeys that were found
*/
public Collection<EntityKey> getEntityKeys() {
return entityKeys;
}
@Override
protected boolean nextStep(ResponseMessage message) throws IOException {
if (message instanceof FindNodeResponse) {
return handleNodeResponse((FindNodeResponse)message);
}
if (!(message instanceof FindValueResponse)) {
throw new IllegalArgumentException("this is a find value handler");
}
FindValueResponse response = (FindValueResponse)message;
if (!extractDataFromResponse(response)) {
return false;
}
addToResponsePath(response);
// Terminate the FIND_VALUE lookup if it isn't
// an exhaustive lookup
if (!exchaustive) {
killActiveSearches();
return false;
}
// Continue otherwise...
return true;
}
@Override
protected int getDefaultParallelism() {
return LookupSettings.FIND_VALUE_PARALLEL_LOOKUPS.getValue();
}
@Override
protected boolean isTimeout(long time) {
long lookupTimeout = LookupSettings.FIND_VALUE_LOOKUP_TIMEOUT.getValue();
return lookupTimeout > 0L && time >= lookupTimeout;
}
@Override
protected LookupRequest createLookupRequest(Contact node) {
Collection<KUID> noKeys = Collections.emptySet();
return context.getMessageHelper().createFindValueRequest(
node.getContactAddress(), lookupId, noKeys, lookupKey.getDHTValueType());
}
private boolean extractDataFromResponse(FindValueResponse response) {
Contact sender = response.getContact();
Collection<KUID> availableSecondaryKeys = response.getSecondaryKeys();
Collection<? extends DHTValueEntity> entities = response.getDHTValueEntities();
// No keys and no values? In other words the remote Node sent us
// a FindValueResponse even though it doesn't have a value for
// the given KUID!? Continue with the lookup if so...!
if (availableSecondaryKeys.isEmpty() && entities.isEmpty()) {
if (LOG.isWarnEnabled()) {
LOG.warn(sender + " returned neither keys nor values for " + lookupId);
}
// Continue with the lookup...
return false;
}
Collection<? extends DHTValueEntity> filtered
= DatabaseUtils.filter(lookupKey.getDHTValueType(), entities);
// The filtered Set is empty and the unfiltered isn't?
// The remote Node send us unrequested Value(s)!
// Continue with the lookup if so...!
if (filtered.isEmpty() && !entities.isEmpty()) {
if (LOG.isWarnEnabled()) {
LOG.warn(sender + " returned unrequested types of values for " + lookupId);
}
// Continue with the lookup...
return false;
}
this.entities.addAll(filtered);
for (KUID secondaryKey : availableSecondaryKeys) {
EntityKey key = EntityKey.createEntityKey(
sender, lookupId, secondaryKey, lookupKey.getDHTValueType());
this.entityKeys.add(key);
}
return true;
}
}