CassandraSessionImpl.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.cyclop.service.cassandra.intern;

import javax.annotation.PreDestroy;
import javax.inject.Inject;
import javax.inject.Named;
import javax.validation.constraints.NotNull;

import net.jcip.annotations.NotThreadSafe;

import org.cyclop.common.AppConfig;
import org.cyclop.model.CassandraVersion;
import org.cyclop.model.exception.AuthenticationRequiredException;
import org.cyclop.service.cassandra.CassandraSession;
import org.cyclop.validation.EnableValidation;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.context.annotation.Scope;
import org.springframework.context.annotation.ScopedProxyMode;

import com.datastax.driver.core.Cluster;
import com.datastax.driver.core.HostDistance;
import com.datastax.driver.core.PoolingOptions;
import com.datastax.driver.core.Session;
import com.datastax.driver.core.SocketOptions;
import com.datastax.driver.core.exceptions.InvalidQueryException;

/** @author Maciej Miklas */
@NotThreadSafe
@Named
@Scope(value = "session", proxyMode = ScopedProxyMode.TARGET_CLASS)
@EnableValidation
public class CassandraSessionImpl implements CassandraSession {
	private final static Logger LOG = LoggerFactory.getLogger(CassandraSessionImpl.class);

	private transient Session session;

	@Inject
	private AppConfig appConfig;

	private CassandraVersion cassandraVersion;

	private transient Cluster cluster;

	public synchronized void authenticate(@NotNull String userName, @NotNull String password) {
		if (session != null) {
			return;
		}
		try {
			Cluster.Builder builder = Cluster.builder();
			for (String host : appConfig.cassandra.hosts.split("[,]")) {
				builder.addContactPoint(host);
			}
			builder.withCredentials(userName, password);

			if (appConfig.cassandra.useSsl) {
				builder.withSSL();
			}

			SocketOptions socketOptions = new SocketOptions();
			socketOptions.setConnectTimeoutMillis(appConfig.cassandra.timeoutMillis);

			PoolingOptions pooling = new PoolingOptions();
			pooling.setCoreConnectionsPerHost(HostDistance.LOCAL, appConfig.cassandra.coreConnectionsPerHost);
			pooling.setMaxConnectionsPerHost(HostDistance.LOCAL, appConfig.cassandra.maxConnectionsPerHost);
			pooling.setMinSimultaneousRequestsPerConnectionThreshold(HostDistance.LOCAL,
					appConfig.cassandra.minSimultaneousRequestsPerConnectionThreshold);
			pooling.setMaxSimultaneousRequestsPerConnectionThreshold(HostDistance.LOCAL,
					appConfig.cassandra.maxSimultaneousRequestsPerConnectionThreshold);

			cluster = builder.withPort(appConfig.cassandra.port).withSocketOptions(socketOptions)
					.withPoolingOptions(pooling).build();
			session = cluster.connect();

			cassandraVersion = determineVersion(session);
		} finally {
			if (session == null) {
				LOG.debug("Cannot open cassandra session - clean up resources");
				close();
			}
		}
	}

	private CassandraVersion determineVersion(Session session) {
		CassandraVersion ver = CassandraVersion.VER_2_1;

		// this way to check version sucks and works at the same time ....
		try {
			session.execute("select type_name from system.schema_usertypes");
		} catch (InvalidQueryException e) {
			ver = CassandraVersion.VER_2_0;
		}

		try {
			session.execute("select type FROM system.schema_columns LIMIT 1 ALLOW FILTERING");
		} catch (InvalidQueryException e) {
			ver = CassandraVersion.VER_1_2;
		}
		return ver;
	}

	@Override
	public CassandraVersion getCassandraVersion() {
		checkAuthenticated();
		return cassandraVersion;
	}

	@Override
	public synchronized Session getSession() {
		checkAuthenticated();
		return session;
	}

	public synchronized void close() {
		if (cluster != null) {
			try {
				cluster.close();
			} catch (Exception e) {
				LOG.warn("Error while shutting down the cluster", e);
			}
			cluster = null;
			session = null;
		}
	}

	private void checkAuthenticated() {
		if (!isOpen()) {
			throw new AuthenticationRequiredException("Cassandra session not found");
		}
	}

	@Override
	public synchronized boolean isOpen() {
		return session != null;

	}

	@PreDestroy
	public synchronized void cleanup() {
		close();
	}

}