/*
* 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.jclouds.scriptbuilder.functionloader.osgi;
import org.jclouds.scriptbuilder.domain.OsFamily;
import org.jclouds.scriptbuilder.domain.ShellToken;
import org.jclouds.scriptbuilder.functionloader.FunctionLoader;
import org.jclouds.scriptbuilder.functionloader.FunctionNotFoundException;
import org.osgi.framework.BundleContext;
import org.osgi.framework.InvalidSyntaxException;
import org.osgi.framework.ServiceReference;
import com.google.common.base.Strings;
/**
* A {@link FunctionLoader} implementation which delegates loading to the OSGi service registry.
*/
public class ServiceFunctionLoader implements FunctionLoader {
private final BundleContext bundleContext;
public ServiceFunctionLoader(BundleContext bundleContext) {
this.bundleContext = bundleContext;
}
/**
* Looks up the service registry for an applicable {@link FunctionLoader} and delegates to it.
*
* @param function
* The function name to load.
* @param family
* This operating system family of the function.
* @return The function as {@link String}
* @throws FunctionNotFoundException
*/
@Override
public String loadFunction(String function, OsFamily family) throws FunctionNotFoundException {
ServiceReference[] references = null;
String filter = String.format("(function=*%s.%s*)", function, ShellToken.SH.to(family));
try {
references = bundleContext.getServiceReferences(FunctionLoader.class.getName(), filter);
if (references != null) {
for (ServiceReference reference : references) {
FunctionLoader loader = (FunctionLoader) bundleContext.getService(reference);
String f = loader.loadFunction(function, family);
if (!Strings.isNullOrEmpty(f)) {
return f;
}
}
}
} catch (InvalidSyntaxException e) {
throw new FunctionNotFoundException(function, family, e);
} finally {
if (references != null) {
for (ServiceReference reference : references) {
bundleContext.ungetService(reference);
}
}
}
throw new FunctionNotFoundException(function, family);
}
}