/*
* This file is part of ELKI:
* Environment for Developing KDD-Applications Supported by Index-Structures
*
* Copyright (C) 2017
* ELKI Development Team
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program 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 Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
package de.lmu.ifi.dbs.elki.database;
import java.util.Collection;
import de.lmu.ifi.dbs.elki.data.type.SimpleTypeInformation;
import de.lmu.ifi.dbs.elki.database.datastore.DataStoreFactory;
import de.lmu.ifi.dbs.elki.database.datastore.DataStoreUtil;
import de.lmu.ifi.dbs.elki.database.datastore.WritableDataStore;
import de.lmu.ifi.dbs.elki.database.ids.ArrayStaticDBIDs;
import de.lmu.ifi.dbs.elki.database.ids.DBIDArrayIter;
import de.lmu.ifi.dbs.elki.database.ids.DBIDUtil;
import de.lmu.ifi.dbs.elki.database.ids.DBIDs;
import de.lmu.ifi.dbs.elki.database.relation.DBIDView;
import de.lmu.ifi.dbs.elki.database.relation.MaterializedRelation;
import de.lmu.ifi.dbs.elki.database.relation.Relation;
import de.lmu.ifi.dbs.elki.datasource.DatabaseConnection;
import de.lmu.ifi.dbs.elki.datasource.FileBasedDatabaseConnection;
import de.lmu.ifi.dbs.elki.datasource.bundle.MultipleObjectsBundle;
import de.lmu.ifi.dbs.elki.index.Index;
import de.lmu.ifi.dbs.elki.index.IndexFactory;
import de.lmu.ifi.dbs.elki.logging.Logging;
import de.lmu.ifi.dbs.elki.logging.statistics.Duration;
import de.lmu.ifi.dbs.elki.utilities.documentation.Description;
import de.lmu.ifi.dbs.elki.utilities.optionhandling.parameterization.Parameterization;
import de.lmu.ifi.dbs.elki.utilities.optionhandling.parameters.ObjectListParameter;
import de.lmu.ifi.dbs.elki.utilities.optionhandling.parameters.ObjectParameter;
/**
* This database class uses array-based storage and thus does not allow for
* dynamic insert, delete and update operations. However, array access is
* expected to be faster and use less memory.
*
* @author Arthur Zimek
* @author Erich Schubert
* @since 0.2
*
* @apiviz.landmark
* @apiviz.composedOf ArrayStaticDBIDs
* @apiviz.uses DatabaseConnection
*/
@Description("Database using an in-memory hashtable and at least providing linear scans.")
public class StaticArrayDatabase extends AbstractDatabase {
/**
* Our logger
*/
private static final Logging LOG = Logging.getLogger(StaticArrayDatabase.class);
/**
* IDs of this database
*/
private ArrayStaticDBIDs ids;
/**
* The DBID representation we use
*/
private DBIDView idrep;
/**
* The data source we get the initial data from.
*/
protected DatabaseConnection databaseConnection;
/**
* Constructor.
*
* @param databaseConnection Database connection to get the initial data from.
* @param indexFactories Indexes to add
*/
public StaticArrayDatabase(DatabaseConnection databaseConnection, Collection<IndexFactory<?, ?>> indexFactories) {
super();
this.databaseConnection = databaseConnection;
this.ids = null;
this.idrep = null;
// Add indexes.
if(indexFactories != null) {
this.indexFactories.addAll(indexFactories);
}
}
/**
* Constructor with no indexes.
*/
public StaticArrayDatabase() {
this(null, null);
}
/**
* Initialize the database by getting the initial data from the database
* connection.
*/
@Override
public void initialize() {
if(databaseConnection != null) {
if(LOG.isDebugging()) {
LOG.debugFine("Loading data from database connection.");
}
MultipleObjectsBundle bundle = databaseConnection.loadData();
// Run at most once.
databaseConnection = null;
// Find DBIDs for bundle
{
DBIDs bids = bundle.getDBIDs();
if(bids instanceof ArrayStaticDBIDs) {
this.ids = (ArrayStaticDBIDs) bids;
}
else if(bids == null) {
this.ids = DBIDUtil.generateStaticDBIDRange(bundle.dataLength());
}
else {
this.ids = (ArrayStaticDBIDs) DBIDUtil.makeUnmodifiable(bids);
}
}
// Replace id representation (it would be nicer if we would not need
// DBIDView at all)
this.idrep = new DBIDView(this.ids);
relations.add(this.idrep);
getHierarchy().add(this, idrep);
DBIDArrayIter it = this.ids.iter();
int numrel = bundle.metaLength();
for(int i = 0; i < numrel; i++) {
SimpleTypeInformation<?> meta = bundle.meta(i);
@SuppressWarnings("unchecked")
SimpleTypeInformation<Object> ometa = (SimpleTypeInformation<Object>) meta;
WritableDataStore<Object> store = DataStoreUtil.makeStorage(ids, DataStoreFactory.HINT_DB, ometa.getRestrictionClass());
for(it.seek(0); it.valid(); it.advance()) {
store.put(it, bundle.data(it.getOffset(), i));
}
Relation<?> relation = new MaterializedRelation<>(ometa, ids, null, store);
relations.add(relation);
getHierarchy().add(this, relation);
// Try to add indexes where appropriate
for(IndexFactory<?, ?> factory : indexFactories) {
if(factory.getInputTypeRestriction().isAssignableFromType(ometa)) {
@SuppressWarnings("unchecked")
final IndexFactory<Object, ?> ofact = (IndexFactory<Object, ?>) factory;
@SuppressWarnings("unchecked")
final Relation<Object> orep = (Relation<Object>) relation;
final Index index = ofact.instantiate(orep);
Duration duration = LOG.isStatistics() ? LOG.newDuration(index.getClass().getName() + ".construction").begin() : null;
index.initialize();
if(duration != null) {
LOG.statistics(duration.end());
}
getHierarchy().add(relation, index);
}
}
}
// fire insertion event
eventManager.fireObjectsInserted(ids);
}
}
@Override
protected Logging getLogger() {
return LOG;
}
/**
* Parameterization class.
*
* @author Erich Schubert
*
* @apiviz.exclude
*/
public static class Parameterizer extends AbstractDatabase.Parameterizer {
/**
* Holds the database connection to get the initial data from.
*/
protected DatabaseConnection databaseConnection = null;
/**
* Indexes to add.
*/
private Collection<IndexFactory<?, ?>> indexFactories;
@Override
protected void makeOptions(Parameterization config) {
super.makeOptions(config);
// Get database connection.
final ObjectParameter<DatabaseConnection> dbcP = new ObjectParameter<>(DATABASE_CONNECTION_ID, DatabaseConnection.class, FileBasedDatabaseConnection.class);
if(config.grab(dbcP)) {
databaseConnection = dbcP.instantiateClass(config);
}
// Get indexes.
final ObjectListParameter<IndexFactory<?, ?>> indexFactoryP = new ObjectListParameter<>(INDEX_ID, IndexFactory.class, true);
if(config.grab(indexFactoryP)) {
indexFactories = indexFactoryP.instantiateClasses(config);
}
}
@Override
protected StaticArrayDatabase makeInstance() {
return new StaticArrayDatabase(databaseConnection, indexFactories);
}
}
}