com.lithium.flow.jetty.JettyClient Maven / Gradle / Ivy

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/*
 * Copyright 2015 Lithium Technologies, 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 com.lithium.flow.jetty;

import static com.google.common.base.Preconditions.checkNotNull;

import com.lithium.flow.config.Config;
import com.lithium.flow.util.ConfigObjectPool;
import com.lithium.flow.util.HostUtils;
import com.lithium.flow.util.Logs;
import com.lithium.flow.util.Unchecked;

import java.io.Closeable;
import java.io.IOException;
import java.net.URI;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.atomic.AtomicInteger;

import javax.annotation.Nonnull;

import org.apache.commons.pool.BasePoolableObjectFactory;
import org.apache.commons.pool.ObjectPool;
import org.eclipse.jetty.util.ssl.SslContextFactory;
import org.eclipse.jetty.websocket.api.Session;
import org.eclipse.jetty.websocket.api.annotations.OnWebSocketMessage;
import org.eclipse.jetty.websocket.api.annotations.WebSocket;
import org.eclipse.jetty.websocket.client.ClientUpgradeRequest;
import org.eclipse.jetty.websocket.client.WebSocketClient;
import org.slf4j.Logger;

import com.google.common.base.Splitter;

/**
 * @author Matt Ayres
 */
@WebSocket
public class JettyClient extends BasePoolableObjectFactory implements Closeable {
	private static final Logger log = Logs.getLogger();

	private final Map> tokens = new ConcurrentHashMap<>();
	private final AtomicInteger pos = new AtomicInteger();
	private final Config config;
	private final WebSocketClient client;
	private final ObjectPool pool;
	private final long timeout;

	public JettyClient(@Nonnull Config config) {
		this.config = checkNotNull(config);

		client = new WebSocketClient(new SslContextFactory());
		client.getPolicy().setMaxTextMessageSize(config.getInt("maxTextMessageSize", 1024 * 1024));
		client.getPolicy().setIdleTimeout(config.getTime("idleTimeout", "1h"));
		Unchecked.run(client::start);

		pool = new ConfigObjectPool<>(this, config);

		timeout = config.getTime("timeout", "15s");
	}

	@Override
	@Nonnull
	public Session makeObject() throws IOException {
		List urls = HostUtils.expand(config.getList("url", Splitter.on(' ')));
		Collections.rotate(urls, pos.decrementAndGet() % urls.size());
		for (String url : urls) {
			log.debug("connecting: {}", url);
			try {
				return client.connect(this, new URI(url), new ClientUpgradeRequest()).get();
			} catch (Exception e) {
				log.warn("failed to connect to url: {}", url, e);
			}
		}
		throw new IOException("unable to connect to any url: " + urls);
	}

	@Override
	public void destroyObject(@Nonnull Session session) throws Exception {
		session.close();
	}

	@Override
	public boolean validateObject(@Nonnull Session session) {
		return session.isOpen();
	}

	@Nonnull
	public String call(@Nonnull String text) throws IOException {
		return call(text, input -> input);
	}

	@Nonnull
	public  T call(@Nonnull String text, @Nonnull Decoder decoder) throws IOException {
		checkNotNull(text);
		checkNotNull(decoder);

		Session session = Unchecked.get(pool::borrowObject);
		try {
			Token token = new Token<>(decoder);
			tokens.put(session, token);
			session.getRemote().sendStringByFuture(text);
			return token.get(timeout);
		} finally {
			Unchecked.run(() -> pool.returnObject(session));
		}
	}

	@OnWebSocketMessage
	public void onInput(@Nonnull Session session, @Nonnull String input) {
		log.debug("input: {}", input);

		Token token = tokens.remove(session);
		if (token == null) {
			log.warn("no token for input: {}", input);
			return;
		}

		if (input.startsWith("ERROR: ")) {
			token.exception(new RuntimeException(input));
		} else {
			try {
				token.set(input);
			} catch (Exception e) {
				token.exception(e);
			}
		}
	}

	@Override
	public void close() {
		try {
			client.stop();
		} catch (Exception e) {
			throw new RuntimeException("failed to close web socket client", e);
		}
	}
}