FirehoseBuilder.java

/*
 *   Copyright (c) 2015 Intellectual Reserve, Inc.  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 cf.dropsonde.firehose;

import org.cloudfoundry.dropsonde.events.Envelope;
import io.netty.channel.EventLoopGroup;
import io.netty.channel.socket.SocketChannel;
import rx.Observable;

import java.net.URI;
import java.util.UUID;

/**
 * @author Mike Heath
 */
public class FirehoseBuilder {

	private URI firehoseUrl;
	private String token;
	private String subscriptionId = UUID.randomUUID().toString();
	private boolean skipTlsValidation;

	private EventLoopGroup eventLoopGroup;
	private Class<? extends SocketChannel> channelClass;

	public static FirehoseBuilder create(String firehoseUrl, String token) {
		return new FirehoseBuilder(firehoseUrl, token);
	}

	public static FirehoseBuilder create(URI firehoseUrl, String token) {
		return new FirehoseBuilder(firehoseUrl, token);
	}

	public FirehoseBuilder(String firehoseUrl, String token) {
		this(URI.create(firehoseUrl), token);
	}

	public FirehoseBuilder(URI firhoseUrl, String token) {
		this.firehoseUrl = firhoseUrl;
		final String scheme = firhoseUrl.getScheme();
		if (!"ws".equalsIgnoreCase(scheme) && !"wss".equalsIgnoreCase(scheme)) {
			throw new IllegalArgumentException("Only ws/wss URLs are accepted (i.e. wss://loggregator.mycf.example.com)");
		}

		this.token = token;
	}

	public FirehoseBuilder subscriptionId(String subscriptionId) {
		this.subscriptionId = subscriptionId;
		return this;
	}

	public FirehoseBuilder eventLoopGroup(EventLoopGroup eventLoopGroup, Class<? extends SocketChannel> channelClass) {
		this.eventLoopGroup = eventLoopGroup;
		this.channelClass = channelClass;
		return this;
	}

	public FirehoseBuilder skipTlsValidation(boolean skipTlsValidation) {
		this.skipTlsValidation = skipTlsValidation;
		return this;
	}

	public Firehose build() {
		return new Firehose() {

			final NettyFirehoseOnSubscribe onSubscribe = new NettyFirehoseOnSubscribe(
					firehoseUrl,
					token,
					subscriptionId,
					skipTlsValidation,
					eventLoopGroup,
					channelClass
			);
			volatile boolean closed = false;

			@Override
			public void close() {
				closed = true;
				onSubscribe.close();
			}

			@Override
			public boolean isClosed() {
				return closed;
			}

			@Override
			public boolean isConnected() {
				return onSubscribe.isConnected();
			}

			@Override
			public Observable<Envelope> open() {
				if (closed) {
					throw new IllegalStateException("The firehose client is closed.");
				}

				return Observable
						.create(onSubscribe)
						.publish()
						.refCount();
			}
		};
	}

}