component-dsl/src/main/java/org/apache/aries/component/dsl/internal/OSGiImpl.java

/*
 * 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.aries.component.dsl.internal;

import org.apache.aries.component.dsl.*;

/**
 * @author Carlos Sierra Andrés
 */
public class OSGiImpl<T> extends BaseOSGiImpl<T> {

	protected OSGiImpl(OSGiRunnable<T> operation) {
		super(new ErrorHandlerOSGiRunnable<>(operation));
	}

	static <T extends Throwable> void rethrow(Throwable t) throws T {
		throw (T)t;
	}

	public static <T> OSGi<T> create(OSGiRunnable<T> runnable) {
		return new OSGiImpl<>(runnable);
	}

	protected static class ErrorHandlerOSGiRunnable<T>
		implements OSGiRunnable<T> {

		private final OSGiRunnable<T> operation;

		public ErrorHandlerOSGiRunnable(OSGiRunnable<T> operation) {
			this.operation = operation;
		}

		@Override
		public OSGiResult run(
			ExecutionContext ec, Publisher<? super T> op) {

			return operation.run(ec,
				wrap(op, t -> {
					try {
						return op.publish(t);
					} catch (PublisherRethrowException pre) {
						rethrow(pre.getCause());

						return null;
					} catch (Exception e) {
						return op.error(t, e);
					}
				}));
		}
	}
}