/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.apache.felix.dm.runtime;
import java.util.ArrayList;
import java.util.Dictionary;
import java.util.List;
import org.apache.felix.dm.Dependency;
import org.apache.felix.dm.DependencyActivation;
import org.apache.felix.dm.DependencyService;
/**
* This is a custom DependencyManager Dependency, allowing to take control of when the dependency
* is available or not. It's used in the context of the LifecycleController class, in order to
* activate/deactivate a Component on demand.
*
* @author <a href="mailto:dev@felix.apache.org">Felix Project Team</a>
*/
public class ToggleServiceDependency implements Dependency, DependencyActivation
{
private final List<Object> m_services = new ArrayList<Object>();
private volatile boolean m_isAvailable;
private volatile boolean m_stopped;
public ToggleServiceDependency()
{
}
public ToggleServiceDependency(boolean isAvailable)
{
m_isAvailable = isAvailable;
}
public void setAvailable(boolean isAvailable)
{
synchronized (this)
{
if (m_stopped)
{
return;
}
boolean changed = m_isAvailable != isAvailable;
m_isAvailable = isAvailable;
if (! changed) {
return;
}
}
// invoked on every change
if (m_isAvailable)
{
Object[] services = m_services.toArray();
for (int i = 0; i < services.length; i++)
{
DependencyService ds = (DependencyService) services[i];
ds.dependencyAvailable(this);
if (!isRequired())
{
invokeAdded(ds);
}
}
}
else
{
Object[] services = m_services.toArray();
for (int i = 0; i < services.length; i++)
{
DependencyService ds = (DependencyService) services[i];
ds.dependencyUnavailable(this);
if (!isRequired())
{
invokeRemoved(ds);
}
}
}
}
public Dependency createCopy()
{
return new ToggleServiceDependency(m_isAvailable);
}
public Object getAutoConfigInstance()
{
return "" + m_isAvailable;
}
public String getAutoConfigName()
{
return null;
}
public Class<?> getAutoConfigType()
{
return String.class;
}
@SuppressWarnings("unchecked")
public Dictionary getProperties()
{
return null;
}
public void invokeAdded(DependencyService service)
{
}
public void invokeRemoved(DependencyService service)
{
}
public void invoke(DependencyService dependencyService, String name)
{
}
public boolean isAutoConfig()
{
return false;
}
public boolean isAvailable()
{
return m_isAvailable;
}
public boolean isInstanceBound()
{
return true;
}
public boolean isPropagated()
{
return false;
}
public boolean isRequired()
{
return true;
}
public void start(DependencyService service)
{
synchronized (this)
{
m_services.add(service);
m_stopped = false;
}
}
public void stop(DependencyService service)
{
synchronized (this)
{
m_services.remove(service);
m_stopped = true;
}
}
}