bundles/org.eclipse.equinox.log.stream/osgi/src/org/osgi/util/pushstream/PushStreamBuilder.java

/*
 * Copyright (c) OSGi Alliance (2015, 2017). All Rights Reserved.
 * 
 * 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.osgi.util.pushstream;

import java.util.concurrent.BlockingQueue;
import java.util.concurrent.Executor;
import java.util.concurrent.ScheduledExecutorService;

import org.osgi.annotation.versioning.ProviderType;

/**
 * A Builder for a PushStream. This Builder extends the support of a standard
 * BufferBuilder by allowing the PushStream to be unbuffered.
 * 
 *
 * @param <T> The type of objects in the {@link PushEvent}
 * @param <U> The type of the Queue used in the user specified buffer
 */
@ProviderType
public interface PushStreamBuilder<T, U extends BlockingQueue<PushEvent< ? extends T>>>
		extends BufferBuilder<PushStream<T>,T,U> {

	/**
	 * Tells this {@link PushStreamBuilder} to create an unbuffered stream which
	 * delivers events directly to its consumer using the incoming delivery
	 * thread. Setting the {@link PushStreamBuilder} to be unbuffered means that
	 * any buffer, queue policy or push back policy will be ignored. Note that
	 * calling one of:
	 * <ul>
	 * <li>{@link #withBuffer(BlockingQueue)}</li>
	 * <li>{@link #withQueuePolicy(QueuePolicy)}</li>
	 * <li>{@link #withQueuePolicy(QueuePolicyOption)}</li>
	 * <li>{@link #withPushbackPolicy(PushbackPolicy)}</li>
	 * <li>{@link #withPushbackPolicy(PushbackPolicyOption, long)}</li>
	 * <li>{@link #withParallelism(int)}</li>
	 * </ul>
	 * after this method will reset this builder to require a buffer.
	 * 
	 * @return the builder
	 */
	PushStreamBuilder<T,U> unbuffered();

	/*
	 * Overridden methods to allow the covariant return of a PushStreamBuilder
	 */

	@Override
	PushStreamBuilder<T,U> withBuffer(U queue);

	@Override
	PushStreamBuilder<T,U> withQueuePolicy(QueuePolicy<T,U> queuePolicy);

	@Override
	PushStreamBuilder<T,U> withQueuePolicy(QueuePolicyOption queuePolicyOption);

	@Override
	PushStreamBuilder<T,U> withPushbackPolicy(
			PushbackPolicy<T,U> pushbackPolicy);

	@Override
	PushStreamBuilder<T,U> withPushbackPolicy(
			PushbackPolicyOption pushbackPolicyOption, long time);

	@Override
	PushStreamBuilder<T,U> withParallelism(int parallelism);

	@Override
	PushStreamBuilder<T,U> withExecutor(Executor executor);

	@Override
	PushStreamBuilder<T,U> withScheduler(ScheduledExecutorService scheduler);
}