HttpCollectionConfigFactory.java

/*******************************************************************************
 * This file is part of OpenNMS(R).
 *
 * Copyright (C) 2006-2011 The OpenNMS Group, Inc.
 * OpenNMS(R) is Copyright (C) 1999-2011 The OpenNMS Group, Inc.
 *
 * OpenNMS(R) is a registered trademark of The OpenNMS Group, Inc.
 *
 * OpenNMS(R) is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published
 * by the Free Software Foundation, either version 3 of the License,
 * or (at your option) any later version.
 *
 * OpenNMS(R) is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with OpenNMS(R).  If not, see:
 *      http://www.gnu.org/licenses/
 *
 * For more information contact:
 *     OpenNMS(R) Licensing <license@opennms.org>
 *     http://www.opennms.org/
 *     http://www.opennms.com/
 *******************************************************************************/

package org.opennms.netmgt.config;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.util.List;

import org.apache.commons.io.IOUtils;
import org.exolab.castor.xml.MarshalException;
import org.exolab.castor.xml.ValidationException;
import org.opennms.core.utils.ConfigFileConstants;
import org.opennms.core.utils.ThreadCategory;
import org.opennms.core.xml.CastorUtils;
import org.opennms.netmgt.config.httpdatacollection.HttpCollection;
import org.opennms.netmgt.config.httpdatacollection.HttpDatacollectionConfig;
import org.opennms.netmgt.model.RrdRepository;

/**
 * <p>HttpCollectionConfigFactory class.</p>
 *
 * @author <a href="mailto:david@opennms.org">David Hustace</a>
 * @version $Id: $
 */
public class HttpCollectionConfigFactory {
    /** The singleton instance. */
    private static HttpCollectionConfigFactory m_instance;

    private static boolean m_loadedFromFile = false;

    /** Boolean indicating if the init() method has been called. */
    protected boolean initialized = false;

    /** Timestamp of the http collection config, used to know when to reload from disk. */
    protected static long m_lastModified;

    private static HttpDatacollectionConfig m_config;

    /**
     * <p>Constructor for HttpCollectionConfigFactory.</p>
     *
     * @param configFile a {@link java.lang.String} object.
     * @throws org.exolab.castor.xml.MarshalException if any.
     * @throws org.exolab.castor.xml.ValidationException if any.
     * @throws java.io.IOException if any.
     */
    public HttpCollectionConfigFactory(String configFile) throws MarshalException, ValidationException, IOException {
        InputStream is = null;
        try {
            is = new FileInputStream(configFile);
            initialize(is);
        } finally {
            if (is != null) {
                IOUtils.closeQuietly(is);
            }
        }
    }

    /**
     * <p>Constructor for HttpCollectionConfigFactory.</p>
     *
     * @param stream a {@link java.io.InputStream} object.
     * @throws org.exolab.castor.xml.MarshalException if any.
     * @throws org.exolab.castor.xml.ValidationException if any.
     */
    public HttpCollectionConfigFactory(InputStream stream) throws MarshalException, ValidationException {
        initialize(stream);
    }

    private void initialize(InputStream stream) throws MarshalException, ValidationException {
        log().debug("initialize: initializing http collection config factory.");
        m_config = CastorUtils.unmarshal(HttpDatacollectionConfig.class, stream);
    }

    /**
     * Be sure to call this method before calling getInstance().
     *
     * @throws java.io.IOException if any.
     * @throws java.io.FileNotFoundException if any.
     * @throws org.exolab.castor.xml.MarshalException if any.
     * @throws org.exolab.castor.xml.ValidationException if any.
     */
    public static synchronized void init() throws IOException, FileNotFoundException, MarshalException, ValidationException {
        
        if (m_instance == null) {
            File cfgFile = ConfigFileConstants.getFile(ConfigFileConstants.HTTP_COLLECTION_CONFIG_FILE_NAME);
            m_instance = new HttpCollectionConfigFactory(cfgFile.getPath());
            m_lastModified = cfgFile.lastModified();
            m_loadedFromFile = true;
        }
    }

    /**
     * Singleton static call to get the only instance that should exist
     *
     * @return the single factory instance
     * @throws java.lang.IllegalStateException
     *             if init has not been called
     */
    public static synchronized HttpCollectionConfigFactory getInstance() {
        
        if (m_instance == null) {
            throw new IllegalStateException("You must call HttpCollectionConfigFactory.init() before calling getInstance().");
        }
        return m_instance;
    }
    
    /**
     * <p>setInstance</p>
     *
     * @param instance a {@link org.opennms.netmgt.config.HttpCollectionConfigFactory} object.
     */
    public static synchronized void setInstance(HttpCollectionConfigFactory instance) {
        m_instance = instance;
        m_loadedFromFile = false;
    }

    /**
     * <p>reload</p>
     *
     * @throws java.io.IOException if any.
     * @throws java.io.FileNotFoundException if any.
     * @throws org.exolab.castor.xml.MarshalException if any.
     * @throws org.exolab.castor.xml.ValidationException if any.
     */
    public synchronized void reload() throws IOException, FileNotFoundException, MarshalException, ValidationException {
        m_instance = null;
        init();
    }


    /**
     * Reload the http-datacollection-config.xml file if it has been changed since we last
     * read it.
     *
     * @throws java.io.IOException if any.
     * @throws org.exolab.castor.xml.MarshalException if any.
     * @throws org.exolab.castor.xml.ValidationException if any.
     */
    protected void updateFromFile() throws IOException, MarshalException, ValidationException {
        if (m_loadedFromFile) {
            File surveillanceViewsFile = ConfigFileConstants.getFile(ConfigFileConstants.HTTP_COLLECTION_CONFIG_FILE_NAME);
            if (m_lastModified != surveillanceViewsFile.lastModified()) {
                this.reload();
            }
        }
    }

    /**
     * <p>getConfig</p>
     *
     * @return a {@link org.opennms.netmgt.config.httpdatacollection.HttpDatacollectionConfig} object.
     */
    public synchronized static HttpDatacollectionConfig getConfig() {
        return m_config;
    }

    /**
     * <p>setConfig</p>
     *
     * @param m_config a {@link org.opennms.netmgt.config.httpdatacollection.HttpDatacollectionConfig} object.
     */
    public synchronized static void setConfig(HttpDatacollectionConfig m_config) {
        HttpCollectionConfigFactory.m_config = m_config;
    }

    private ThreadCategory log() {
        return ThreadCategory.getInstance();
    }

    /**
     * <p>getHttpCollection</p>
     *
     * @param collectionName a {@link java.lang.String} object.
     * @return a {@link org.opennms.netmgt.config.httpdatacollection.HttpCollection} object.
     */
    public HttpCollection getHttpCollection(String collectionName) {
        List<HttpCollection> collections = m_config.getHttpCollectionCollection();
        HttpCollection collection = null;
        for (HttpCollection coll : collections) {
            if (coll.getName().equalsIgnoreCase(collectionName)) {
                collection = coll;
                break;
            }
        }
        if (collection == null) {
            throw new IllegalArgumentException("getHttpCollection: collection name: "
                    +collectionName+" specified in collectd configuration not found in http collection configuration.");
        }
        return collection;
    }

    /**
     * <p>getRrdRepository</p>
     *
     * @param collectionName a {@link java.lang.String} object.
     * @return a {@link org.opennms.netmgt.model.RrdRepository} object.
     */
    public RrdRepository getRrdRepository(String collectionName) {
        RrdRepository repo = new RrdRepository();
        repo.setRrdBaseDir(new File(getRrdPath()));
        repo.setRraList(getRRAList(collectionName));
        repo.setStep(getStep(collectionName));
        repo.setHeartBeat((2 * getStep(collectionName)));
        return repo;
    }
    
    /**
     * <p>getStep</p>
     *
     * @param cName a {@link java.lang.String} object.
     * @return a int.
     */
    public int getStep(String cName) {
        HttpCollection collection = getHttpCollection(cName);
        if (collection != null)
            return collection.getRrd().getStep();
        else
            return -1;
    }
    
    /**
     * <p>getRRAList</p>
     *
     * @param cName a {@link java.lang.String} object.
     * @return a {@link java.util.List} object.
     */
    public List<String> getRRAList(String cName) {
       HttpCollection collection = getHttpCollection(cName);
        if (collection != null)
            return collection.getRrd().getRraCollection();
        else
            return null;

    }
    
    /**
     * <p>getRrdPath</p>
     *
     * @return a {@link java.lang.String} object.
     */
    public String getRrdPath() {
        String rrdPath = m_config.getRrdRepository();
        if (rrdPath == null) {
            throw new RuntimeException("Configuration error, failed to "
                    + "retrieve path to RRD repository.");
        }
    
        /*
         * TODO: make a path utils class that has the below in it strip the
         * File.separator char off of the end of the path.
         */
        if (rrdPath.endsWith(File.separator)) {
            rrdPath = rrdPath.substring(0, (rrdPath.length() - File.separator.length()));
        }
        
        return rrdPath;
    }

}