/*
* Copyright 2009-2012 Roger Kapsi
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.ardverk.dht.io;
import java.io.IOException;
import javax.inject.Inject;
import javax.inject.Provider;
import javax.inject.Singleton;
import org.ardverk.dht.message.MessageFactory;
import org.ardverk.dht.message.MessageType;
import org.ardverk.dht.message.RequestMessage;
import org.ardverk.dht.message.ResponseMessage;
import org.ardverk.dht.message.ValueRequest;
import org.ardverk.dht.routing.Contact;
import org.ardverk.dht.routing.RouteTable;
import org.ardverk.dht.rsrc.Key;
import org.ardverk.dht.rsrc.Value;
import org.ardverk.dht.storage.Datastore;
/**
* The {@link ValueRequestHandler} handles {@link ValueRequest}
* ({@link MessageType#FIND_VALUE}) messages.
*/
@Singleton
public class ValueRequestHandler extends AbstractRequestHandler {
private final RouteTable routeTable;
private final Datastore datastore;
@Inject
public ValueRequestHandler(
Provider<MessageDispatcher> messageDispatcher,
RouteTable routeTable,
Datastore datastore) {
super(messageDispatcher);
this.routeTable = routeTable;
this.datastore = datastore;
}
@Override
public ResponseMessage handleRequest(RequestMessage message) throws IOException {
ValueRequest request = (ValueRequest)message;
Contact src = request.getContact();
Key key = request.getKey();
Value value = datastore.get(src, key);
MessageFactory factory = getMessageFactory();
ResponseMessage response = null;
if (value != null) {
response = factory.createValueResponse(request, value);
} else {
Contact[] contacts = routeTable.select(key.getId());
response = factory.createNodeResponse(request, contacts);
}
return response;
}
}