view flys-artifacts/src/main/java/de/intevation/flys/artifacts/datacage/DBConfig.java @ 5779:ebec12def170

Datacage: Add a pool of builders to make it multi threadable. XML DOM is not thread safe. Therefore the old implementation only allowed one thread to use the builder at a time. As the complexity of the configuration has increased over time this has become a bottleneck of the whole application because it took quiet some time to build a result. Furthermore the builder code path is visited very frequent. So many concurrent requests were piled up resulting in long waits for the users. To mitigate this problem a round robin pool of builders is used now. Each of the pooled builders has an independent copy of the XML template and can be run in parallel. The number of builders is determined by the system property 'flys.datacage.pool.size'. It defaults to 4.
author Sascha L. Teichmann <teichmann@intevation.de>
date Sun, 21 Apr 2013 12:48:09 +0200
parents 5642a83420f2
children
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package de.intevation.flys.artifacts.datacage;

import de.intevation.artifacts.common.utils.Config;

import de.intevation.artifactdatabase.db.SQL;
import de.intevation.artifactdatabase.db.DBConnection;

import org.apache.log4j.Logger;

public class DBConfig
{
    private static Logger logger = Logger.getLogger(DBConfig.class);

     /**
     * XPath to access the database driver within the global configuration.
     */
    public static final String DB_DRIVER =
        "/artifact-database/datacage/driver/text()";
    /**
     * XPath to access the database URL within the global configuration.
     */
    public static final String DB_URL =
        "/artifact-database/datacage/url/text()";
    /**
     * XPath to access the database use within the global configuration.
     */
    public static final String DB_USER =
        "/artifact-database/datacage/user/text()";
    /**
     * XPath to access the database password within the global configuration.
     */
    public static final String DB_PASSWORD =
        "/artifact-database/datacage/password/text()";

    /**
     * The default database driver: H2
     */
    public static final String DEFAULT_DRIVER =
        "org.h2.Driver";

    /**
     * The default database user: ""
     */
    public static final String DEFAULT_USER = "";

    /**
     * The default database password: ""
     */
    public static final String DEFAULT_PASSWORD = "";


    public static final String DEFAULT_URL =
        "jdbc:h2:mem:datacage;INIT=RUNSCRIPT FROM '${artifacts.config.dir}/datacage.sql'";

    public static final String RESOURCE_PATH = "/datacage-sql";

    private static DBConfig instance;

    protected DBConnection dbConnection;
    protected SQL          sql;

    public DBConfig() {
    }

    public DBConfig(DBConnection dbConnection, SQL sql) {
        this.dbConnection = dbConnection;
        this.sql          = sql;
    }

    public static synchronized DBConfig getInstance() {
        if (instance == null) {
            instance = createInstance();
        }
        return instance;
    }

    protected static DBConfig createInstance() {
        String driver = Config.getStringXPath(
            DB_DRIVER, DEFAULT_DRIVER);

        String url = Config.getStringXPath(
            DB_URL, DEFAULT_URL);

        url = Config.replaceConfigDir(url);

        String user = Config.getStringXPath(
            DB_USER, DEFAULT_USER);

        String password = Config.getStringXPath(
            DB_PASSWORD, DEFAULT_PASSWORD);

        DBConnection dbConnection = new DBConnection(
            driver, url, user, password);

        SQL sql = new SQL(DBConfig.class, RESOURCE_PATH, driver);

        return new DBConfig(dbConnection, sql);
    }

    public DBConnection getDBConnection() {
        return dbConnection;
    }

    public SQL getSQL() {
        return sql;
    }
}
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