/*
 * Copyright Terracotta, Inc.
 *
 * 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.ehcache.core.osgi;

import org.osgi.framework.BundleContext;
import org.osgi.framework.InvalidSyntaxException;
import org.osgi.framework.ServiceReference;

import java.util.Collection;
import java.util.List;
import java.util.stream.Stream;

import static java.util.stream.Collectors.toList;

An OSGi service based equivalent to ServiceLoader. 
 This class is used by the ServiceLocator (via ClassLoading.servicesOfType(Class)) to discover services when running inside an OSGi environment. This is needed when the required Ehcache services are split across multiple OSGi bundles. /**
 * An OSGi service based equivalent to {@link java.util.ServiceLoader}.
 * <p>
 * This class is used by the {@link org.ehcache.core.spi.ServiceLocator ServiceLocator} (via
 * {@link org.ehcache.core.util.ClassLoading#servicesOfType(Class) ClassLoading.servicesOfType(Class)}) to discover services when running inside an OSGi
 * environment. This is needed when the required Ehcache services are split across multiple OSGi bundles.
 */
public class OsgiServiceLoader {

  
Locate all services of type T. 
Params:
serviceType – concrete service class
Type parameters:
<T> – service type
Returns:
an iterable of T services/**
   * Locate all services of type {@code T}.
   *
   * @param serviceType concrete service class
   * @param <T> service type
   * @return an iterable of {@code T} services
   */
  public static <T> Iterable<T> load(Class<T> serviceType) {
    try {
      BundleContext coreBundle = EhcacheActivator.getCoreBundle();
      return coreBundle.getServiceReferences(serviceType, null).stream().map(coreBundle::getService).collect(toList());
    } catch (InvalidSyntaxException e) {
      throw new AssertionError(e);
    }
  }
}