/*
* 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.db;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;
import org.limewire.mojito.db.impl.DefaultDHTValueFactory;
import org.limewire.mojito.exceptions.DHTValueException;
import org.limewire.mojito.routing.Version;
/**
* Manages multiple instances of a {@link DHTValueFactory}.
*/
public class DHTValueFactoryManager {
public static final DHTValueFactory defaultFactory = new DefaultDHTValueFactory();
private final Map<DHTValueType, DHTValueFactory> factories
= Collections.synchronizedMap(new HashMap<DHTValueType, DHTValueFactory>());
/**
* Adds a new <code>DHTValueFactory</code>.
*/
public DHTValueFactory addValueFactory(DHTValueType valueType, DHTValueFactory factory) {
if (valueType == null) {
throw new NullPointerException("DHTValueType is null");
}
if (factory == null) {
throw new NullPointerException("DHTValueFactory is null");
}
return factories.put(valueType, factory);
}
/**
* Removes a <code>DHTValueFactory</code> that is registered under the given
* <code>DHTValueType</code>.
*/
public DHTValueFactory removeValueFactory(DHTValueType valueType) {
if (valueType == null) {
throw new NullPointerException("DHTValueType is null");
}
return factories.remove(valueType);
}
/**
* Returns a <code>DHTValueFactory</code> for the given
* <code>DHTValueType</code> or the <code>defaultFactory</code> if none
* exists.
*/
public DHTValueFactory getValueFactory(DHTValueType valueType) {
if (valueType == null) {
throw new NullPointerException("DHTValueType is null");
}
DHTValueFactory factory = factories.get(valueType);
if (factory != null) {
return factory;
}
return defaultFactory;
}
/**<p>
* Creates a <code>DHTValue</code> from the given arguments. This
* method takes care of empty values by creating a <code>DHTValue</code>
* via the default {@link DHTValueFactory}.
* </p>
* <code>createDHTValue</code> throws a {@link DHTValueException} for
* null <code>DHTValueType</code> or a null <code>Version</code>.
*/
public DHTValue createDHTValue(DHTValueType valueType,
Version version, byte[] value) throws DHTValueException {
if (valueType == null) {
throw new NullPointerException("DHTValueType is null");
}
if (version == null) {
throw new NullPointerException("Version is null");
}
if (value == null || value.length == 0) {
return defaultFactory.createDHTValue(valueType, version, value);
}
return getValueFactory(valueType).createDHTValue(valueType, version, value);
}
}