/*******************************************************************************
 * Copyright (c) 2000, 2009 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.test.internal.performance.results.db;

import java.io.File;
import java.io.PrintWriter;
import java.io.StringWriter;
import java.math.BigDecimal;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.StringTokenizer;

import org.eclipse.core.runtime.Assert;
import org.eclipse.test.internal.performance.PerformanceTestPlugin;
import org.eclipse.test.internal.performance.data.Dim;
import org.eclipse.test.internal.performance.db.DB;
import org.eclipse.test.internal.performance.results.utils.IPerformancesConstants;
import org.eclipse.test.internal.performance.results.utils.Util;
import org.eclipse.test.performance.Dimension;

/**
 * Specific and private implementation of {@link org.eclipse.test.internal.performance.db.DB} class
 * to get massive results from performance results database.
 * TODO (frederic) Should be at least a subclass of {@link DB}...
 */
public class DB_Results {


	private static final String DEFAULT_DB_BASELINE_PREFIX = "R-";
	private static final Dim[] NO_DIMENSION = new Dim[0];
	private static final String[] EMPTY_LIST = new String[0];
	static final boolean DEBUG = false;
    static final boolean LOG = false;

    // the two supported DB types
    private static final String DERBY= "derby"; //$NON-NLS-1$
    private static final String CLOUDSCAPE= "cloudscape"; //$NON-NLS-1$

    private static DB_Results fgDefault;

    private Connection fConnection;
    private SQL_Results fSQL;
//    private boolean fIsEmbedded;
    private String fDBType;	// either "derby" or "cloudscape"

	    // Preferences info
    public static boolean DB_CONNECTION = false;
    private static String DB_NAME;
    private static String DB_LOCATION;
	private static String DB_BASELINE_PREFIX = DEFAULT_DB_BASELINE_PREFIX;
	private static String DB_VERSION;
	private static String DB_VERSION_REF;

	/**
	 * Get the name of the database.
	 *
	 * @return The name as a string.
	 */
    public static String getDbName() {
    	if (DB_NAME == null) initDbContants();
    	return DB_NAME;
    }

	/**
	 * Set the name of the database.
	 *
	 * @param dbName The name as a string.
	 */
    public static void setDbName(String dbName) {
    	Assert.isNotNull(dbName);
    	DB_NAME = dbName;
    }

	/**
	 * Get the location of the database.
	 *
	 * @return The location as a string.
	 */
    public static String getDbLocation() {
    	if (!DB_CONNECTION) return null;
    	if (DB_LOCATION == null) initDbContants();
    	return DB_LOCATION;
    }

	/**
	 * Set the location of the database.
	 *
	 * @param dbLocation The location as a string.
	 */
    public static void setDbLocation(String dbLocation) {
    	Assert.isNotNull(dbLocation);
    	DB_LOCATION = dbLocation;
    }

	/**
	 * Get the default baseline prefix.
	 *
	 * @return The prefix as a string.
	 */
    public static String getDbBaselinePrefix() {
    	return DB_BASELINE_PREFIX;
    }

	/**
	 * Set the baseline prefix of the database.
	 *
	 * @param baselinePrefix The prefix as a string.
	 */
    public static void setDbDefaultBaselinePrefix(String baselinePrefix) {
    	Assert.isNotNull(baselinePrefix);
    	Assert.isTrue(baselinePrefix.startsWith(DEFAULT_DB_BASELINE_PREFIX));
    	DB_BASELINE_PREFIX = baselinePrefix;
    }

	/**
	 * Get the baseline reference version of the database.
	 *
	 * @return The version as a string.
	 */
    public static String getDbBaselineRefVersion() {
    	if (DB_VERSION_REF == null) initDbContants();
    	return DB_VERSION_REF;
    }

	/**
	 * Get the version of the database.
	 *
	 * @return The version as a string.
	 */
    public static String getDbVersion() {
    	if (DB_VERSION == null) initDbContants();
    	return DB_VERSION;
    }

	/**
	 * Set the version of the database.
	 *
	 * @param version The version as a string.
	 */
    public static void setDbVersion(String version) {
    	Assert.isNotNull(version);
    	Assert.isTrue(version.startsWith("v3"));
    	DB_VERSION = version;
    }

	/**
	 * Update the database constants from a new database location.
	 * @param connected Tells whether the database should be connected or not.
	 * @param databaseLocation The database location.
	 * 	May be a path to a local folder or a net address
	 * 	(see {@link IPerformancesConstants#NETWORK_DATABASE_LOCATION}).
	 */
	public static boolean updateDbConstants(boolean connected, int eclipseVersion, String databaseLocation) {
		shutdown();
		DB_CONNECTION = connected;
		DB_LOCATION = databaseLocation == null ? IPerformancesConstants.NETWORK_DATABASE_LOCATION : databaseLocation;
		DB_NAME = IPerformancesConstants.DATABASE_NAME_PREFIX + eclipseVersion;
		DB_VERSION = "v" + eclipseVersion;
		DB_VERSION_REF = "R-3." + (eclipseVersion % 10 - 1);
		if (connected) {
			return getDefault().fSQL != null;
		}
		return true;
	}

	/**
	 * Returns a title including DB version and name.
	 *
	 * @return A title as a string.
	 */
	public static String getDbTitle() {
    	if (!DB_CONNECTION) return null;
		String title = "Eclipse " + DB_VERSION + " - ";
		if (DB_LOCATION.startsWith("net:")) {
			title += " Network DB";
		} else {
			title += " Local DB";
		}
		return title;
	}

	/**
	 * The list of all the configurations (i.e. machine) stored in the database.
	 */
	private static String[] CONFIGS;

	/**
	 * The list of all the components stored in the database.
	 */
	private static String[] COMPONENTS;

	/**
	 * The list of all the builds stored in the database.
	 */
	private static String[] BUILDS;

	/**
	 * The list of all the dimensions stored in the database.
	 */
	private static int[] DIMENSIONS;

	/**
	 * The default dimension used to display results (typically in fingerprints).
	 */
	private static Dim DEFAULT_DIM;
	private static int DEFAULT_DIM_INDEX;

	/**
	 * The list of all the dimensions displayed while generating results.
	 */
	private static Dim[] RESULTS_DIMENSIONS;

	/**
	 * The list of all the VMs stored in the database.
	 */
	private static String[] VMS;

	/**
	 * The list of possible test boxes.
	 * <p>
	 * Only used if no specific configurations are specified
	 * (see {@link PerformanceResults#readAll(String, String[][], String, File, int, org.eclipse.core.runtime.IProgressMonitor)}.
	 * </p>
	 * Note that this is a copy of the the property "eclipse.perf.config.descriptors"
	 * defined in org.eclipse.releng.eclipsebuilder/eclipse/helper.xml file
	 */
	private static String[] CONFIG_DESCRIPTIONS;

	/**
	 * The list of known Eclipse components.
	 */
	private final static String[] ECLIPSE_COMPONENTS = {
		"org.eclipse.ant", //$NON-NLS-1$
		"org.eclipse.compare", //$NON-NLS-1$
		"org.eclipse.core", //$NON-NLS-1$
		"org.eclipse.help", //$NON-NLS-1$
		"org.eclipse.jdt.core", //$NON-NLS-1$
		"org.eclipse.jdt.debug", //$NON-NLS-1$
		"org.eclipse.jdt.text", //$NON-NLS-1$
		"org.eclipse.jdt.ui", //$NON-NLS-1$
		"org.eclipse.jface", //$NON-NLS-1$
		"org.eclipse.osgi", //$NON-NLS-1$
		"org.eclipse.pde.api.tools", //$NON-NLS-1$
		"org.eclipse.pde.ui", //$NON-NLS-1$
		"org.eclipse.swt", //$NON-NLS-1$
		"org.eclipse.team", //$NON-NLS-1$
		"org.eclipse.ua", //$NON-NLS-1$
		"org.eclipse.ui" //$NON-NLS-1$
	};
	private static String[] KNOWN_COMPONENTS = ECLIPSE_COMPONENTS;


	    // Store debug info
	final static StringWriter DEBUG_STR_WRITER;
	final static PrintWriter DEBUG_WRITER;
	static {
		if (DEBUG) {
			DEBUG_STR_WRITER= new StringWriter();
			DEBUG_WRITER= new PrintWriter(DEBUG_STR_WRITER);
		} else {
			DEBUG_STR_WRITER= null;
			DEBUG_WRITER= null;
		}
	}

    // Store log info
    final static StringWriter LOG_STR_WRITER = new StringWriter();
    final static LogWriter LOG_WRITER = new LogWriter();
    static class LogWriter extends PrintWriter {
		long[] starts = new long[10];
		long[] times = new long[10];
    	StringBuffer[] buffers = new StringBuffer[10];
    	int depth = -1, max = -1;
    	public LogWriter() {
	        super(LOG_STR_WRITER);
        }
		void starts(String log) {
    		if (++this.depth >= this.buffers.length) {
    			System.arraycopy(this.times, 0, this.times = new long[this.depth+10], 0, this.depth);
    			System.arraycopy(this.buffers, 0, this.buffers= new StringBuffer[this.depth+10], 0, this.depth);
    		}
    		StringBuffer buffer = this.buffers[this.depth];
    		if (this.buffers[this.depth] == null) buffer = this.buffers[this.depth] = new StringBuffer();
    		buffer.append(log);
    		this.starts[this.depth] = System.currentTimeMillis();
    		if (this.depth > this.max) this.max = this.depth;
    	}
		void ends(String log) {
			if (this.depth < 0)
				throw new RuntimeException("Invalid call to ends (missing corresponding starts call)!"); //$NON-NLS-1$
    		this.buffers[this.depth].append(log);
    		if (this.depth > 0) {
    			this.times[this.depth] += System.currentTimeMillis() - this.starts[this.depth];
    			this.depth--;
    			return;
    		}
    		for (int i=0; i<this.max; i++) {
	    		print(this.buffers[i].toString());
	    		print(" ( in "); //$NON-NLS-1$
	    		print(this.times[this.depth]);
    			println("ms)"); //$NON-NLS-1$
    		}
    		this.depth = this.max = -1;
			this.starts = new long[10];
			this.times = new long[10];
    		this.buffers = new StringBuffer[10];
    	}
		public String toString() {
	        return LOG_STR_WRITER.toString();
        }
    }

	// Data storage from queries
	static String LAST_CURRENT_BUILD, LAST_BASELINE_BUILD;
	private static int BUILDS_LENGTH;
	private static String[] SCENARII;
	private static String[] COMMENTS;

    //---- private implementation

	/**
     * Private constructor to block instance creation.
     */
    private DB_Results() {
    	// empty implementation
    }

    synchronized static DB_Results getDefault() {
        if (fgDefault == null) {
            fgDefault= new DB_Results();
            fgDefault.connect();
            if (PerformanceTestPlugin.getDefault() == null) {
            	// not started as plugin
	            Runtime.getRuntime().addShutdownHook(
	                new Thread() {
	                    public void run() {
	                    	shutdown();
	                    }
	                }
	            );
            }
        } else if (fgDefault.fSQL == null) {
        	fgDefault.connect();
        }
        return fgDefault;
    }

    public static void shutdown() {
        if (fgDefault != null) {
            fgDefault.disconnect();
            fgDefault= null;
            BUILDS = null;
            LAST_BASELINE_BUILD = null;
            LAST_CURRENT_BUILD = null;
            CONFIGS = null;
            COMPONENTS = null;
            SCENARII = null;
            COMMENTS = null;
            DB_VERSION = null;
            DB_VERSION_REF = null;
            DEFAULT_DIM =null;
            DEFAULT_DIM_INDEX = -1;
            RESULTS_DIMENSIONS = null;
            VMS = null;
            CONFIG_DESCRIPTIONS = null;
            KNOWN_COMPONENTS = ECLIPSE_COMPONENTS;
        }
        if (DEBUG) {
        	DEBUG_WRITER.println("DB.shutdown"); //$NON-NLS-1$
        	System.out.println(DEBUG_STR_WRITER.toString());
        }
        if (LOG) {
        	System.out.println(LOG_STR_WRITER.toString());
        }
    }

/**
 * Return the build id from a given name.
 *
 * @param name The build name (eg. I20070615-1200)
 * @return The id of the build (ie. the index in the {@link #BUILDS} list)
 */
static int getBuildId(String name) {
	if (BUILDS == null) return -1;
	return Arrays.binarySearch(BUILDS, name, Util.BUILD_DATE_COMPARATOR);
}

/**
 * Return the build name from a given id.
 *
 * @param id The build id
 * @return The name of the build (eg. I20070615-1200)
 */
static String getBuildName(int id) {
	if (BUILDS == null) return null;
	return BUILDS[id];
}

/**
 * Returns all the builds names read from the database.
 *
 * @return The list of all builds names matching the scenario pattern used while reading data
 */
public static String[] getBuilds() {
	if (BUILDS == null) {
		queryAllVariations("%"); //$NON-NLS-1$
	}
	if (BUILDS_LENGTH == 0) return EMPTY_LIST;
	String[] builds = new String[BUILDS_LENGTH];
	System.arraycopy(BUILDS, 0, builds, 0, BUILDS_LENGTH);
	return builds;
}

/**
 * Get component name from a scenario.
 *
 * @param scenarioName The name of the scenario
 * @return The component name
 */
static String getComponentNameFromScenario(String scenarioName) {
	int length = KNOWN_COMPONENTS.length;
	for (int i=0; i<length; i++) {
		if (scenarioName.startsWith(KNOWN_COMPONENTS[i])) {
			return KNOWN_COMPONENTS[i];
		}
	}
	StringTokenizer tokenizer = new StringTokenizer(scenarioName, ".");
	StringBuffer buffer = new StringBuffer(tokenizer.nextToken());
	if (tokenizer.hasMoreTokens()) {
		buffer.append('.');
		buffer.append(tokenizer.nextToken());
		if (tokenizer.hasMoreTokens()) {
			buffer.append('.');
			buffer.append(tokenizer.nextToken());
		}
	}
	String componentName = buffer.toString();
	System.err.println(scenarioName+" does not belongs to a known Eclipse component. So use scenario prefix "+componentName+" as component name by default and add it to the know components"); //$NON-NLS-1$
	System.arraycopy(KNOWN_COMPONENTS, 0, KNOWN_COMPONENTS = new String[length+1], 0, length);
	KNOWN_COMPONENTS[length] = componentName;
	return componentName;
}

/**
 * Get all components read from database.
 *
 * @return A list of component names matching the given pattern
 */
public static String[] getComponents() {
	if (COMPONENTS == null) return EMPTY_LIST;
	int length = COMPONENTS.length;
	String[] components = new String[length];
	System.arraycopy(COMPONENTS, 0, components, 0, length);
	return components;
}

/**
 * Return the name of the configuration from the given id.
 *
 * @param id The index of the configuration in the stored list.
 * @return The name of the configuration (eg. eclipseperflnx1_R3.3)
 */
static String getConfig(int id) {
	return CONFIGS[id];
}

/**
 * Get all configurations read from the database.
 *
 * @return A list of configuration names
 */
public static String[] getConfigs() {
	if (CONFIGS == null) return EMPTY_LIST;
	int length = CONFIGS.length;
	String[] configs = new String[length];
	System.arraycopy(CONFIGS, 0, configs, 0, length);
	return configs;
}

/**
 * Set the default dimension used for performance results.
 */
public static void setConfigs(String[] configs) {
	CONFIGS = configs;
}

/**
 * Get all configurations read from the database.
 *
 * @return A list of configuration names
 */
public static String[] getConfigDescriptions() {
	if (CONFIG_DESCRIPTIONS == null) {
		String[] configs = getConfigs();
		int length = configs.length;
		CONFIG_DESCRIPTIONS = new String[length];
		String[][] configDescriptors = PerformanceTestPlugin.getConfigDescriptors();
		int cdLength = configDescriptors.length;
		for (int i = 0; i < length; i++) {
			for (int j = 0; j < cdLength; j++) {
				if (configDescriptors[j][0].equals(configs[i])) {
			        CONFIG_DESCRIPTIONS[i] = configDescriptors[j][1];
			        break;
				}
			}
        }
	}
	int length = CONFIG_DESCRIPTIONS.length;
	String[] descriptions = new String[length];
	System.arraycopy(CONFIG_DESCRIPTIONS, 0, descriptions, 0, length);
	return descriptions;
}

/**
 * Set the default dimension used for performance results.
 */
public static void setConfigDescriptions(String[] descriptions) {
	CONFIG_DESCRIPTIONS = descriptions;
}

/**
 * Get all dimensions read from the database.
 *
 * @return A list of dimensions.
 */
public static Dim[] getDimensions() {
	if (DIMENSIONS == null) return NO_DIMENSION;
	int length = DIMENSIONS.length;
	Dim[] dimensions = new Dim[length];
	for (int i = 0; i < length; i++) {
		Dimension dimension = PerformanceTestPlugin.getDimension(DIMENSIONS[i]);
		if (dimension == null) {
			throw new RuntimeException("There is an unsupported dimension stored in the database: " +DIMENSIONS[i]);
		}
		dimensions[i] = (Dim) dimension;
    }
	return dimensions;
}

/**
 * Return the default dimension used for performance results.
 *
 * @return The {@link Dim default dimension}.
 */
public static Dim getDefaultDimension() {
	if (DEFAULT_DIM == null) {
		DEFAULT_DIM = (Dim) PerformanceTestPlugin.getDefaultDimension();
	}
	return DEFAULT_DIM;
}

/**
 * Set the default dimension used for performance results.
 */
public static void setDefaultDimension(String dim) {
	DEFAULT_DIM = (Dim) PerformanceTestPlugin.getDimension(dim);
	if (DIMENSIONS != null) {
		DEFAULT_DIM_INDEX = Arrays.binarySearch(DIMENSIONS, DEFAULT_DIM.getId());
	}
}

public static Dim[] getResultsDimensions() {
	if (RESULTS_DIMENSIONS == null) {
		Dimension[] resultsDimensions = PerformanceTestPlugin.getResultsDimensions();
		int length = resultsDimensions.length;
		RESULTS_DIMENSIONS = new Dim[length];
		for (int i = 0; i < length; i++) {
			RESULTS_DIMENSIONS[i] = (Dim) resultsDimensions[i];
		}
	}
	return RESULTS_DIMENSIONS;
}

/**
 * Set the default dimension used for performance results.
 */
public static void setResultsDimensions(String[] dimensions) {
	int length = dimensions.length;
	RESULTS_DIMENSIONS = new Dim[length];
	for (int i = 0; i < length; i++) {
		RESULTS_DIMENSIONS[i] = (Dim) PerformanceTestPlugin.getDimension(dimensions[i]);
	}
}

/**
 * Return the default dimension used for performance results.
 *
 * @return The {@link Dim default dimension}.
 */
public static int getDefaultDimensionIndex() {
	if (DEFAULT_DIM == null || DEFAULT_DIM_INDEX == -1) {
		getDefaultDimension(); // init default dimension
		getDimensions(); // init dimensions
		DEFAULT_DIM_INDEX = Arrays.binarySearch(DIMENSIONS, DEFAULT_DIM.getId());
	}
	return DEFAULT_DIM_INDEX;
}

/**
 * Return the ID of the last baseline build before the given date.
 *
 * @param date The date the baseline must be run before. If <code>null</code>
 * 	return the last baseline build stored in the DB.
 *
 * @return the ID of the last baseline build before the given date or
 * 	<code>null</code> if none was run before it...
 */
public static String getLastBaselineBuild(String date) {
	if (BUILDS == null) {
		queryAllVariations("%"); //$NON-NLS-1$
	}
	if (date == null) {
		if (LAST_BASELINE_BUILD == null) {
			return BUILDS[0];
		}
		return LAST_BASELINE_BUILD;
	}
	String lastBaselineBuild = null;
	for (int i=0; i<BUILDS_LENGTH; i++) {
		String build = BUILDS[i];
		if (build.startsWith(DB_BASELINE_PREFIX)) {
			String buildDate = build.substring(build.indexOf('_')+1);
			if (buildDate.compareTo(date) < 0) {
				if (lastBaselineBuild == null || build.compareTo(lastBaselineBuild) > 0) {
					lastBaselineBuild = build;
				}
			}
		}
	}
	if (lastBaselineBuild == null) {
		return BUILDS[0];
	}
	return lastBaselineBuild;
}

/**
 * Return the ID of the last baseline build.
 *
 * @return the ID of the last baseline build.
 */
public static String getLastCurrentBuild() {
	if (BUILDS == null) {
		queryAllVariations("%"); //$NON-NLS-1$
	}
	return LAST_CURRENT_BUILD;
}

/**
 * Returns all the scenarios names read from the database.
 *
 * @return The list of all scenarios matching the pattern for a given build.
 * @see #internalQueryBuildScenarios(String, String)
 */
public static List getScenarios() {
	return Arrays.asList(SCENARII);
}

/**
 * Init the constants if necessary.
 */
public static void initDbContants() {
	if (DB_LOCATION == null) {
		DB_LOCATION = PerformanceTestPlugin.getDBLocation();
		if (DB_LOCATION == null) {
			new RuntimeException("Cannot connect to the DB without a location!");
		}
	}
	if (DB_NAME == null) {
		DB_NAME = PerformanceTestPlugin.getDBName();
		if (DB_NAME == null) {
			new RuntimeException("Cannot connect to the DB without a name!");
		}
	}
	if (DB_VERSION == null) {
		DB_VERSION = "v" + DB_NAME.substring(DB_NAME.length()-2);
		DB_VERSION_REF = "R-3."+(Character.digit(DB_NAME.charAt(DB_NAME.length()-1), 10)-1);
	}
}

/**
 * Get all scenarios read from database.
 *
 * @return A list of all scenario names matching the default pattern
 */
public static Map queryAllScenarios() {
	return getDefault().internalQueryBuildScenarios("%", null); //$NON-NLS-1$
}

/**
 * Get all scenarios read from database matching a given pattern.
 * Note that all scenarios are returned if the pattern is <code>null</code>.
 *
 * @param scenarioPattern The pattern of the requested scenarios
 * @return A map of all scenarios matching the given pattern.
 * 	The map keys are component names and values are the scenarios list for
 * 	each component.
 */
static Map queryAllScenarios(String scenarioPattern) {
	String pattern = scenarioPattern==null ? "%" : scenarioPattern; //$NON-NLS-1$
	return getDefault().internalQueryBuildScenarios(pattern, null);
}

/**
 * Get all scenarios read from database matching a given pattern.
 * Note that all scenarios are returned if the pattern is <code>null</code>.
 *
 * @param scenarioPattern The pattern of the requested scenarios
 * @param buildName The build name
 * @return A list of scenario names matching the given pattern
 */
static Map queryAllScenarios(String scenarioPattern, String buildName) {
	return getDefault().internalQueryBuildScenarios(scenarioPattern, buildName);
}

/**
 * Get all variations read from database matching a given configuration pattern.
 *
 * @param configPattern The pattern of the requested configurations
 */
static void queryAllVariations(String configPattern) {
	getDefault().internalQueryAllVariations(configPattern);
}

/**
 * Get all summaries from DB for a given scenario and configuration pattern
 *
 * @param scenarioResults The scenario results where to store data
 * @param configPattern The configuration pattern concerned by the query
 * @param builds All builds to get summaries, if <code>null</code>, then all DB
 * 	builds will be concerned.
 */
static void queryScenarioSummaries(ScenarioResults scenarioResults, String configPattern, String[] builds) {
	getDefault().internalQueryScenarioSummaries(scenarioResults, configPattern, builds);
}

/**
 * Query and store all values for given scenario results
 *
 * @param scenarioResults The scenario results where the values has to be put
 * @param configPattern The pattern of the configuration concerned by the query
 * @param buildName Name of the last build on which data were stored locally
 *
*/
static void queryScenarioValues(ScenarioResults scenarioResults, String configPattern, String buildName) {
	getDefault().internalQueryScenarioValues(scenarioResults, configPattern, buildName);
}

/**
 * dbloc=						embed in home directory
 * dbloc=/tmp/performance			embed given location
 * dbloc=net://localhost			connect to local server
 * dbloc=net://www.eclipse.org	connect to remove server
 */
private void connect() {

	if (this.fConnection != null || !DB_CONNECTION)
		return;

	if (DEBUG) DriverManager.setLogWriter(new PrintWriter(System.out));

	// Init DB location and name if not already done
	if (DB_LOCATION == null) {
		initDbContants();
	}

	String url = null;
	java.util.Properties info = new java.util.Properties();

	if (DEBUG) {
		DEBUG_WRITER.println();
		DEBUG_WRITER.println("==========================================================="); //$NON-NLS-1$
		DEBUG_WRITER.println("Database debug information stored while processing"); //$NON-NLS-1$
	}
	if (LOG) {
		LOG_WRITER.println();
		LOG_WRITER.println("==========================================================="); //$NON-NLS-1$
		LOG_WRITER.println("Database log information stored while processing"); //$NON-NLS-1$
	}

	this.fDBType = DERBY; // assume we are using Derby
	try {
		if (DB_LOCATION.startsWith("net://")) { //$NON-NLS-1$
			// remote
//			fIsEmbedded = false;
			// connect over network
			if (DEBUG)
				DEBUG_WRITER.println("Trying to connect over network..."); //$NON-NLS-1$
			Class.forName("com.ibm.db2.jcc.DB2Driver"); //$NON-NLS-1$
			info.put("user", PerformanceTestPlugin.getDBUser()); //$NON-NLS-1$
			info.put("password", PerformanceTestPlugin.getDBPassword()); //$NON-NLS-1$
			info.put("retrieveMessagesFromServerOnGetMessage", "true"); //$NON-NLS-1$ //$NON-NLS-2$
			info.put("create", "true"); //$NON-NLS-1$ //$NON-NLS-2$
			url = DB_LOCATION + '/' + DB_NAME;
		} else if (DB_LOCATION.startsWith("//")) { //$NON-NLS-1$
			// remote
//			fIsEmbedded = false;
			// connect over network
			if (DEBUG)
				DEBUG_WRITER.println("Trying to connect over network..."); //$NON-NLS-1$
			Class.forName("org.apache.derby.jdbc.ClientDriver"); //$NON-NLS-1$
			info.put("user", PerformanceTestPlugin.getDBUser()); //$NON-NLS-1$
			info.put("password", PerformanceTestPlugin.getDBPassword()); //$NON-NLS-1$
			info.put("create", "true"); //$NON-NLS-1$ //$NON-NLS-2$
			url = DB_LOCATION + '/' + DB_NAME;
		} else {
			// workaround for Derby issue:
			// http://nagoya.apache.org/jira/browse/DERBY-1
			if ("Mac OS X".equals(System.getProperty("os.name"))) //$NON-NLS-1$//$NON-NLS-2$
				System.setProperty("derby.storage.fileSyncTransactionLog", "true"); //$NON-NLS-1$ //$NON-NLS-2$

			// embedded
			try {
				Class.forName("org.apache.derby.jdbc.EmbeddedDriver"); //$NON-NLS-1$
//				fIsEmbedded = true;
			} catch (ClassNotFoundException e) {
				Class.forName("com.ihost.cs.jdbc.CloudscapeDriver"); //$NON-NLS-1$
				this.fDBType = CLOUDSCAPE;
			}
			if (DEBUG)
				DEBUG_WRITER.println("Loaded embedded " + this.fDBType); //$NON-NLS-1$
			File f;
			if (DB_LOCATION.length() == 0) {
				String user_home = System.getProperty("user.home"); //$NON-NLS-1$
				if (user_home == null)
					return;
				f = new File(user_home, this.fDBType);
			} else
				f = new File(DB_LOCATION);
			url = new File(f, DB_NAME).getAbsolutePath();
			info.put("user", PerformanceTestPlugin.getDBUser()); //$NON-NLS-1$
			info.put("password", PerformanceTestPlugin.getDBPassword()); //$NON-NLS-1$
			info.put("create", "true"); //$NON-NLS-1$ //$NON-NLS-2$
		}
		try {
			this.fConnection = DriverManager.getConnection("jdbc:" + this.fDBType + ":" + url, info); //$NON-NLS-1$ //$NON-NLS-2$
		} catch (SQLException e) {
			if ("08001".equals(e.getSQLState()) && DERBY.equals(this.fDBType)) { //$NON-NLS-1$
				if (DEBUG)
					DEBUG_WRITER.println("DriverManager.getConnection failed; retrying for cloudscape"); //$NON-NLS-1$
				// try Cloudscape
				this.fDBType = CLOUDSCAPE;
				this.fConnection = DriverManager.getConnection("jdbc:" + this.fDBType + ":" + url, info); //$NON-NLS-1$ //$NON-NLS-2$
			} else
				throw e;
		}
		if (DEBUG)
			DEBUG_WRITER.println("connect succeeded!"); //$NON-NLS-1$

		this.fConnection.setAutoCommit(false);
		this.fSQL = new SQL_Results(this.fConnection);
		this.fConnection.commit();

	} catch (SQLException ex) {
		PerformanceTestPlugin.logError(ex.getMessage());

	} catch (ClassNotFoundException e) {
		PerformanceTestPlugin.log(e);
	}
}

private void disconnect() {
	if (DEBUG)
		DEBUG_WRITER.println("disconnecting from DB"); //$NON-NLS-1$
	if (this.fSQL != null) {
		try {
			this.fSQL.dispose();
		} catch (SQLException e1) {
			PerformanceTestPlugin.log(e1);
		}
		this.fSQL = null;
	}
	if (this.fConnection != null) {
		try {
			this.fConnection.commit();
		} catch (SQLException e) {
			PerformanceTestPlugin.log(e);
		}
		try {
			this.fConnection.close();
		} catch (SQLException e) {
			PerformanceTestPlugin.log(e);
		}
		this.fConnection = null;
	}

	/*
	if (fIsEmbedded) {
		try {
			DriverManager.getConnection("jdbc:" + fDBType + ":;shutdown=true"); //$NON-NLS-1$ //$NON-NLS-2$
		} catch (SQLException e) {
			String message = e.getMessage();
			if (message.indexOf("system shutdown.") < 0) //$NON-NLS-1$
				e.printStackTrace();
		}
	}
	*/
}

/*
 * Return the index of the given configuration in the stored list.
 */
private int getConfigId(String config) {
	if (CONFIGS == null) return -1;
	return Arrays.binarySearch(CONFIGS, config);
}

SQL_Results getSQL() {
    return this.fSQL;
}

/*
 * Query all comments from database
 */
private void internalQueryAllComments() {
	if (this.fSQL == null) return;
	if (COMMENTS != null) return;
	long start = System.currentTimeMillis();
	if (DEBUG) DEBUG_WRITER.print("		[DB query all comments..."); //$NON-NLS-1$
	ResultSet result = null;
	try {
		String[] comments = null;
		result = this.fSQL.queryAllComments();
		while (result.next()) {
			int commentID = result.getInt(1);
			// Ignore kind as there's only one
			// int commentKind = result.getInt(2);
			String comment = result.getString(3);
			if (comments == null) {
				comments = new String[commentID+10];
			} else if (commentID >= comments.length) {
				int length = comments.length;
				System.arraycopy(comments, 0, comments = new String[commentID+10], 0, length);
			}
			comments[commentID] = comment;
		}
		COMMENTS = comments;
	} catch (SQLException e) {
		PerformanceTestPlugin.log(e);
	} finally {
		if (result != null) {
			try {
				result.close();
			} catch (SQLException e1) {
				// ignored
			}
		}
		if (DEBUG) DEBUG_WRITER.println("done in " + (System.currentTimeMillis() - start) + "ms]"); //$NON-NLS-1$ //$NON-NLS-2$
	}
}

/*
 * Query all variations. This method stores all config and build names.
 */
private void internalQueryAllVariations(String configPattern) {
	if (this.fSQL == null) return;
	if (BUILDS != null) return;
	long start = System.currentTimeMillis();
	if (DEBUG) {
		DEBUG_WRITER.print("	- DB query all variations for configuration pattern: "+configPattern); //$NON-NLS-1$
		DEBUG_WRITER.print("..."); //$NON-NLS-1$
	}
	ResultSet result = null;
	try {
		CONFIGS = null;
		BUILDS = null;
		BUILDS_LENGTH = 0;
		result = this.fSQL.queryAllVariations(configPattern);
		while (result.next()) {
			String variation = result.getString(1); //  something like "||build=I20070615-1200||config=eclipseperfwin2_R3.3||jvm=sun|"
			StringTokenizer tokenizer = new StringTokenizer(variation, "=|"); //$NON-NLS-1$
			tokenizer.nextToken(); 												// 'build'
			storeBuildName(tokenizer.nextToken());				// 'I20070615-1200'
			tokenizer.nextToken();												// 'config'
			storeConfig(tokenizer.nextToken()); 	// 'eclipseperfwin2_R3.3'
			tokenizer.nextToken();												// 'jvm'
			storeVm(tokenizer.nextToken());					// 'sun'
		}
		if (BUILDS_LENGTH == 0) {
			BUILDS = EMPTY_LIST;
		} else {
			System.arraycopy(BUILDS, 0, BUILDS = new String[BUILDS_LENGTH], 0, BUILDS_LENGTH);
		}
	} catch (SQLException e) {
		PerformanceTestPlugin.log(e);
	} finally {
		if (result != null) {
			try {
				result.close();
			} catch (SQLException e1) {
				// ignored
			}
		}
		if (DEBUG) DEBUG_WRITER.println("done in " + (System.currentTimeMillis() - start) + "ms]"); //$NON-NLS-1$ //$NON-NLS-2$
	}
}

private Map internalQueryBuildScenarios(String scenarioPattern, String buildName) {
	if (this.fSQL == null) return null;
	long start = System.currentTimeMillis();
	if (DEBUG) {
		DEBUG_WRITER.print("	- DB query all scenarios"); //$NON-NLS-1$
		if (scenarioPattern != null) DEBUG_WRITER.print(" with pattern "+scenarioPattern); //$NON-NLS-1$
		if (buildName != null) DEBUG_WRITER.print(" for build: "+buildName); //$NON-NLS-1$
	}
	ResultSet result = null;
	Map allScenarios = new HashMap();
	try {
		if (buildName == null) {
			result = this.fSQL.queryBuildAllScenarios(scenarioPattern);
		} else {
			result = this.fSQL.queryBuildScenarios(scenarioPattern, buildName);
		}
		int previousId = -1;
		List scenarios = null;
		List scenariosNames = new ArrayList();
		for (int i = 0; result.next(); i++) {
			int id = result.getInt(1);
			String name = result.getString(2);
			scenariosNames.add(name);
			String shortName = result.getString(3);
			int component_id = storeComponent(getComponentNameFromScenario(name));
			if (component_id != previousId) {
				allScenarios.put(COMPONENTS[component_id], scenarios = new ArrayList());
				previousId = component_id;
			}
			scenarios.add(new ScenarioResults(id, name, shortName));
		}
		SCENARII = new String[scenariosNames.size()];
		scenariosNames.toArray(SCENARII);
	} catch (SQLException e) {
		PerformanceTestPlugin.log(e);
	} finally {
		if (result != null) {
			try {
				result.close();
			} catch (SQLException e1) { // ignored
			}
		}
		if (DEBUG) DEBUG_WRITER.println("done in " + (System.currentTimeMillis() - start) + "ms]"); //$NON-NLS-1$ //$NON-NLS-2$
	}
	return allScenarios;
}

private void internalQueryScenarioValues(ScenarioResults scenarioResults, String configPattern, String buildName) {
	if (this.fSQL == null) return;
	if (DEBUG) {
		DEBUG_WRITER.print("	- DB query all data points for config pattern: "+configPattern+" for scenario: " + scenarioResults.getShortName()); //$NON-NLS-1$ //$NON-NLS-2$
		if (buildName != null) DEBUG_WRITER.print(" for build: "+buildName); //$NON-NLS-1$
	}
	internalQueryAllVariations(configPattern); // need to read all variations to have all build names
	ResultSet result = null;
	try {
		int count = 0;

		result = buildName == null
			?	this.fSQL.queryScenarioDataPoints(configPattern, scenarioResults.getId())
			:	this.fSQL.queryScenarioBuildDataPoints(configPattern, scenarioResults.getId(), buildName);
		while (result.next()) {
			int dp_id = result.getInt(1);
			int step = result.getInt(2);
			String variation = result.getString(3); //  something like "|build=I20070615-1200||config=eclipseperfwin2_R3.3||jvm=sun|"
			StringTokenizer tokenizer = new StringTokenizer(variation, "=|"); //$NON-NLS-1$
			tokenizer.nextToken(); 													// 'build'
			int build_id = getBuildId(tokenizer.nextToken());		// 'I20070615-1200'
			tokenizer.nextToken();													// 'config'
			int config_id = getConfigId(tokenizer.nextToken()); 		// 'eclipseperflnx3'
			ResultSet rs2 = this.fSQL.queryDimScalars(dp_id);
			while (rs2.next()) {
				int dim_id = rs2.getInt(1);
				storeDimension(dim_id);
				BigDecimal decimalValue = rs2.getBigDecimal(2);
				long value = decimalValue.longValue();
				if (build_id >= 0) { // build id may be negative (i.e. not stored in the array) if new run starts while we're getting results
					scenarioResults.setValue(build_id, dim_id, config_id, step, value);
				}
				count++;
			}
		}
		if (LOG) LOG_WRITER.ends("		-> " + count + " values read");  //$NON-NLS-1$ //$NON-NLS-2$
	} catch (SQLException e) {
		PerformanceTestPlugin.log(e);
	} finally {
		if (result != null) {
			try {
				result.close();
			} catch (SQLException e1) {
				// ignored
			}
		}
	}
}

private void internalQueryScenarioSummaries(ScenarioResults scenarioResults, String config, String[] builds) {
	if (this.fSQL == null) return;
	long start = System.currentTimeMillis();
	if (DEBUG) {
		DEBUG_WRITER.print("	- DB query all summaries for scenario '"+scenarioResults.getShortName()+"' of '"+config+"' config"); //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
	}
	internalQueryAllComments();
	ResultSet result = null;
	try {
		int scenarioID = scenarioResults.getId();
		// First try to get summaries of elapsed process dimension
		result = this.fSQL.queryScenarioSummaries(scenarioID, config, builds);
		while (result.next()) {
			String variation = result.getString(1); //  something like "|build=I20070615-1200||config=eclipseperfwin2_R3.3||jvm=sun|"
			int summaryKind = result.getShort(2);
			int comment_id = result.getInt(3);
			int dim_id = result.getInt(4);
			if (dim_id != 0) storeDimension(dim_id);
			StringTokenizer tokenizer = new StringTokenizer(variation, "=|"); //$NON-NLS-1$
			tokenizer.nextToken(); 													// 'build'
			String buildName = tokenizer.nextToken();					// 'I20070615-1200'
			tokenizer.nextToken();													// 'config'
			int config_id = getConfigId(tokenizer.nextToken()); 		// 'eclipseperflnx3'
			int build_id = getBuildId(buildName);
			if (build_id >= 0) {
				scenarioResults.setInfos(config_id, build_id, dim_id==0?-1:summaryKind, COMMENTS[comment_id]);
			}
		}
	} catch (SQLException e) {
		PerformanceTestPlugin.log(e);
	} finally {
		if (result != null) {
			try {
				result.close();
			} catch (SQLException e1) {
				// ignored
			}
		}
		if (DEBUG) DEBUG_WRITER.println("done in " + (System.currentTimeMillis() - start) + "ms]"); //$NON-NLS-1$ //$NON-NLS-2$
	}
}

/*
 * Store a build name in the dynamic list.
 * The list is sorted alphabetically.
 */
private int storeBuildName(String build) {
	boolean isVersion = build.startsWith(DB_BASELINE_PREFIX);
	if (BUILDS == null) {
		BUILDS = new String[1];
		BUILDS[BUILDS_LENGTH++] = build;
		if (isVersion) {
			LAST_BASELINE_BUILD = build;
		} else {
			LAST_CURRENT_BUILD = build;
		}
		return 0;
	}
	int idx = Arrays.binarySearch(BUILDS, build, Util.BUILD_DATE_COMPARATOR);
	if (idx >= 0) return idx;
	int index = -idx-1;
	int length = BUILDS.length;
	if (BUILDS_LENGTH == length) {
		String[] array = new String[length+1];
		if (index > 0) System.arraycopy(BUILDS, 0, array, 0, index);
		array[index] = build;
		if (index < length) {
			System.arraycopy(BUILDS, index, array, index+1, length-index);
		}
		BUILDS = array;
	} else if (index < length) {
		System.arraycopy(BUILDS, index, BUILDS, index+1, length-index);
		BUILDS[index] = build;
	}
	BUILDS_LENGTH++;
	if (isVersion) {
		if (LAST_BASELINE_BUILD == null || LAST_CURRENT_BUILD == null) {
			LAST_BASELINE_BUILD = build;
		} else {
			String buildDate = LAST_CURRENT_BUILD.substring(1, 9)+LAST_CURRENT_BUILD.substring(10, LAST_CURRENT_BUILD.length());
			String baselineDate = LAST_BASELINE_BUILD.substring(LAST_BASELINE_BUILD.indexOf('_')+1);
			if (build.compareTo(LAST_BASELINE_BUILD) > 0 && baselineDate.compareTo(buildDate) < 0) {
				LAST_BASELINE_BUILD = build;
			}
		}
	} else {
		if (LAST_CURRENT_BUILD == null || build.substring(1).compareTo(LAST_CURRENT_BUILD.substring(1)) >= 0) {
			LAST_CURRENT_BUILD = build;
		}
	}
	return index;
}

/*
 * Store a configuration in the dynamic list.
 * The list is sorted alphabetically.
 */
private int storeConfig(String config) {
	if (CONFIGS== null) {
		CONFIGS= new String[1];
		CONFIGS[0] = config;
		return 0;
	}
	int idx = Arrays.binarySearch(CONFIGS, config);
	if (idx >= 0) return idx;
	int length = CONFIGS.length;
	System.arraycopy(CONFIGS, 0, CONFIGS = new String[length+1], 0, length);
	CONFIGS[length] = config;
	Arrays.sort(CONFIGS);
	return length;
}

/*
 * Store a component in the dynamic list. The list is sorted alphabetically.
 * Note that the array is rebuilt each time a new component is discovered
 * as this does not happen so often (e.g. eclipse only has 10 components).
 */
private int storeComponent(String component) {
	if (COMPONENTS== null) {
		COMPONENTS= new String[1];
		COMPONENTS[0] = component;
		return 0;
	}
	int idx = Arrays.binarySearch(COMPONENTS, component);
	if (idx >= 0) return idx;
	int length = COMPONENTS.length;
	System.arraycopy(COMPONENTS, 0, COMPONENTS = new String[length+1], 0, length);
	COMPONENTS[length] = component;
	Arrays.sort(COMPONENTS);
	return length;
}

/*
 * Store a dimension in the dynamic list. The list is sorted in ascending order.
 * Note that the array is rebuilt each time a new dimension is discovered
 * as this does not happen so often (e.g. eclipse only stores two dimensions).
 */
public static int storeDimension(int id) {
	if (DIMENSIONS == null) {
		DIMENSIONS = new int[1];
		DIMENSIONS[0] = id;
		return 0;
	}
	int idx = Arrays.binarySearch(DIMENSIONS, id);
	if (idx >= 0) return idx;
	int length = DIMENSIONS.length;
	System.arraycopy(DIMENSIONS, 0, DIMENSIONS = new int[length+1], 0, length);
	DIMENSIONS[length] = id;
	Arrays.sort(DIMENSIONS);
	return length;
}

/*
 * Store a dimension in the dynamic list. The list is sorted alphabetically.
 * Note that the array is rebuilt each time a new dimension is discovered
 * as this does not happen so often (e.g. eclipse only stores two dimensions).
 */
private int storeVm(String vm) {
	if (VMS == null) {
		VMS = new String[1];
		VMS[0] = vm;
		return 0;
	}
	int idx = Arrays.binarySearch(VMS, vm);
	if (idx >= 0) return idx;
	int length = VMS.length;
	System.arraycopy(VMS, 0, VMS = new String[length+1], 0, length);
	VMS[length] = vm;
	Arrays.sort(VMS);
	return length;
}

}