org.apache.stratos.cartridge.agent.registrant.RegistrantDatabase.java Source code

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Here is the source code for org.apache.stratos.cartridge.agent.registrant.RegistrantDatabase.java

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/**
 *  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.stratos.cartridge.agent.registrant;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.stratos.cartridge.agent.InstanceStateNotificationClientThread;
import org.apache.stratos.cartridge.agent.exception.CartridgeAgentException;

import java.io.*;
import java.util.Collections;
import java.util.List;
import java.util.concurrent.CopyOnWriteArrayList;

/**
 * This class represents a database for {@link Registrant}s. Registrants added to this database will be
 * persisted, so that when the Cartridge Agent is restarted, the Registrants can be restored.
 *
 * @see Registrant
 */
public class RegistrantDatabase {
    private static final Log log = LogFactory.getLog(RegistrantDatabase.class);

    private List<Registrant> registrants = new CopyOnWriteArrayList<Registrant>();

    public void add(Registrant registrant) throws CartridgeAgentException {
        if (registrants.contains(registrant) && registrant.running()) {
            throw new CartridgeAgentException(
                    "Active registrant with key " + registrant.getKey() + " already exists");
        }
        synchronized (registrant) {
            if (!isAlreadyAdded(registrant)) {
                persist(registrant);
                registrants.add(registrant);
                log.info("Added registrant " + registrant);

            } else {
                log.info("Registrant " + registrant + "has been already added");
            }
        }
    }

    private void persist(Registrant registrant) throws CartridgeAgentException {
        try {
            ObjectOutput out = null;
            try {
                // Serialize to a file
                if (!new File("registrants").exists() && !new File("registrants").mkdirs()) {
                    throw new IOException("Cannot create registrants directory");
                }
                out = new ObjectOutputStream(
                        new FileOutputStream("registrants" + File.separator + registrant.getKey() + ".ser"));
                out.writeObject(registrant);
                out.close();
            } finally {
                if (out != null) {
                    out.close();
                }
            }
        } catch (IOException e) {
            log.error("Could not serialize registrant " + registrant, e);
        }
    }

    public void stopAll() {
        for (Registrant registrant : registrants) {
            new Thread(new InstanceStateNotificationClientThread(registrant, "INACTIVE")).start();
            registrant.stop();
        }
    }

    public boolean containsActive(Registrant registrant) {
        return registrants.contains(registrant) && registrants.get(registrants.indexOf(registrant)).running();
    }

    public List<Registrant> getRegistrants() {
        return Collections.unmodifiableList(registrants);
    }

    public boolean isAlreadyAdded(Registrant registrant) {

        boolean alreadyAdded = false;
        for (Registrant registrantFromDb : registrants) {
            if (registrantFromDb.getRemoteHost().equals(registrant.getRemoteHost())) {

                PortMapping[] portMappingofRegistrantOfDB = registrantFromDb.getPortMappings();
                PortMapping[] portMappingofRegistrant = registrant.getPortMappings();

                if (portMappingofRegistrant.length != portMappingofRegistrantOfDB.length) {
                    continue;

                } else {
                    alreadyAdded = checkPortMappings(registrant, registrantFromDb);
                }

            } else {
                continue;
            }
        }
        return alreadyAdded;
    }

    private boolean checkPortMappings(Registrant newRegistrant, Registrant existingRegistrant) {

        PortMapping[] portMappingsOfNewRegistrant = newRegistrant.getPortMappings();
        PortMapping[] portMappingsOfExistingRegistrant = existingRegistrant.getPortMappings();

        for (PortMapping portMappingOfNewRegistrant : portMappingsOfNewRegistrant) {
            boolean matchFound = false;
            for (PortMapping portMappingOfExistingRegistrant : portMappingsOfExistingRegistrant) {
                if (portMappingOfExistingRegistrant.equals(portMappingOfNewRegistrant)) {
                    matchFound = true;
                    break;
                }
            }
            if (!matchFound) {
                return false;
            }
        }
        if (log.isDebugEnabled()) {
            log.debug("***********************************Found matching registrant for " + newRegistrant
                    + " in the Registrant database");
        }
        return true;
    }
}