/*
* Copyright (c) 2012,2013 Big Switch Networks, Inc.
*
* Licensed under the Eclipse Public License, Version 1.0 (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.eclipse.org/legal/epl-v10.html
*
* 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.
*
* This file incorporates work covered by the following copyright and
* permission notice:
*
* Originally created by David Erickson, Stanford University
*
* 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.sdnplatform.devicemanager.internal;
import java.util.Collections;
import java.util.EnumSet;
import java.util.Iterator;
import java.util.concurrent.ConcurrentHashMap;
import org.sdnplatform.devicemanager.IDeviceService.DeviceField;
/**
* An index that maps key fields of an entity uniquely to a device key
*/
public class DeviceUniqueIndex extends DeviceIndex {
/**
* The index
*/
private final ConcurrentHashMap<IndexedEntity, Long> index;
/**
* Construct a new device index using the provided key fields
* @param keyFields the key fields to use
*/
public DeviceUniqueIndex(EnumSet<DeviceField> keyFields) {
super(keyFields);
index = new ConcurrentHashMap<IndexedEntity, Long>();
}
// ***********
// DeviceIndex
// ***********
@Override
public Iterator<Long> queryByEntity(Entity entity) {
final Long deviceKey = findByEntity(entity);
if (deviceKey != null)
return Collections.<Long>singleton(deviceKey).iterator();
return Collections.<Long>emptySet().iterator();
}
@Override
public Iterator<Long> getAll() {
return index.values().iterator();
}
@Override
public boolean updateIndex(Device device, Long deviceKey) {
for (Entity e : device.entities) {
IndexedEntity ie = new IndexedEntity(keyFields, e);
if (!ie.hasNonNullKeys()) continue;
Long ret = index.putIfAbsent(ie, deviceKey);
if (ret != null && !ret.equals(deviceKey)) {
// If the return value is non-null, then fail the insert
// (this implies that a device using this entity has
// already been created in another thread).
return false;
}
}
return true;
}
@Override
public void updateIndex(Entity entity, Long deviceKey) {
IndexedEntity ie = new IndexedEntity(keyFields, entity);
if (!ie.hasNonNullKeys()) return;
index.put(ie, deviceKey);
}
@Override
public void removeEntity(Entity entity) {
IndexedEntity ie = new IndexedEntity(keyFields, entity);
index.remove(ie);
}
@Override
public void removeEntity(Entity entity, Long deviceKey) {
IndexedEntity ie = new IndexedEntity(keyFields, entity);
index.remove(ie, deviceKey);
}
// **************
// Public Methods
// **************
/**
* Look up a {@link Device} based on the provided {@link Entity}.
* @param entity the entity to search for
* @return The key for the {@link Device} object if found
*/
public Long findByEntity(Entity entity) {
IndexedEntity ie = new IndexedEntity(keyFields, entity);
Long deviceKey = index.get(ie);
if (deviceKey == null)
return null;
return deviceKey;
}
}