package de.lmu.ifi.dbs.elki.datasource;
/*
This file is part of ELKI:
Environment for Developing KDD-Applications Supported by Index-Structures
Copyright (C) 2012
Ludwig-Maximilians-Universität München
Lehr- und Forschungseinheit für Datenbanksysteme
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/>.
*/
import java.util.List;
import de.lmu.ifi.dbs.elki.datasource.bundle.BundleStreamSource;
import de.lmu.ifi.dbs.elki.datasource.bundle.MultipleObjectsBundle;
import de.lmu.ifi.dbs.elki.datasource.bundle.StreamFromBundle;
import de.lmu.ifi.dbs.elki.datasource.filter.ObjectFilter;
import de.lmu.ifi.dbs.elki.datasource.filter.StreamFilter;
import de.lmu.ifi.dbs.elki.datasource.parser.Parser;
import de.lmu.ifi.dbs.elki.logging.Logging;
import de.lmu.ifi.dbs.elki.utilities.optionhandling.AbstractParameterizer;
import de.lmu.ifi.dbs.elki.utilities.optionhandling.OptionID;
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;
/**
* Abstract super class for all database connections. AbstractDatabaseConnection
* already provides the setting of the database according to parameters.
*
* @author Elke Achtert
*
* @apiviz.uses ObjectFilter
*/
public abstract class AbstractDatabaseConnection implements DatabaseConnection {
/**
* A sign to separate components of a label.
*/
public static final String LABEL_CONCATENATION = " ";
/**
* Filters to apply to the input data.
* <p>
* Key: {@code -dbc.filter}
* </p>
*/
public static final OptionID FILTERS_ID = OptionID.getOrCreateOptionID("dbc.filter", "The filters to apply to the input data.");
/**
* Parameter to specify the parser to provide a database.
* <p>
* Key: {@code -dbc.parser}
* </p>
*/
public static final OptionID PARSER_ID = OptionID.getOrCreateOptionID("dbc.parser", "Parser to provide the database.");
/**
* The filters to invoke
*/
protected List<ObjectFilter> filters;
/**
* Constructor.
*
* @param filters Filters to apply, can be null
*/
protected AbstractDatabaseConnection(List<ObjectFilter> filters) {
this.filters = filters;
}
/**
* Transforms the specified list of objects and their labels into a list of
* objects and their associations.
*
* @param bundle the objects to process
* @return processed objects
*/
protected MultipleObjectsBundle invokeFilters(MultipleObjectsBundle bundle) {
BundleStreamSource prevs = null;
MultipleObjectsBundle prevb = bundle;
if(filters != null) {
for(ObjectFilter filter : filters) {
if(filter instanceof StreamFilter) {
StreamFilter sfilter = (StreamFilter) filter;
if(prevs != null) {
sfilter.init(prevs);
}
else {
sfilter.init(new StreamFromBundle(prevb));
}
prevs = sfilter;
prevb = null;
}
else {
if(prevs != null) {
prevb = filter.filter(MultipleObjectsBundle.fromStream(prevs));
prevs = null;
}
else {
prevb = filter.filter(prevb);
prevs = null;
}
}
}
}
if(prevb != null) {
return prevb;
}
else {
return MultipleObjectsBundle.fromStream(prevs);
}
}
/**
* Transforms the specified list of objects and their labels into a list of
* objects and their associations.
*
* @param bundle the objects to process
* @return processed objects
*/
protected BundleStreamSource invokeFilters(BundleStreamSource bundle) {
BundleStreamSource prevs = bundle;
MultipleObjectsBundle prevb = null;
if(filters != null) {
for(ObjectFilter filter : filters) {
if(filter instanceof StreamFilter) {
StreamFilter sfilter = (StreamFilter) filter;
if(prevs != null) {
sfilter.init(prevs);
}
else {
sfilter.init(new StreamFromBundle(prevb));
}
prevs = sfilter;
prevb = null;
}
else {
if(prevs != null) {
prevb = filter.filter(MultipleObjectsBundle.fromStream(prevs));
prevs = null;
}
else {
prevb = filter.filter(prevb);
prevs = null;
}
}
}
}
if(prevs != null) {
return prevs;
}
else {
return new StreamFromBundle(prevb);
}
}
/**
* Get the logger for this database connection.
*
* @return Logger
*/
protected abstract Logging getLogger();
/**
* Parameterization class.
*
* @author Erich Schubert
*
* @apiviz.exclude
*/
public static abstract class Parameterizer extends AbstractParameterizer {
protected List<ObjectFilter> filters;
protected Parser parser = null;
@Override
protected void makeOptions(Parameterization config) {
super.makeOptions(config);
}
protected void configFilters(Parameterization config) {
final ObjectListParameter<ObjectFilter> filterParam = new ObjectListParameter<ObjectFilter>(FILTERS_ID, ObjectFilter.class, true);
if(config.grab(filterParam)) {
filters = filterParam.instantiateClasses(config);
}
}
protected void configParser(Parameterization config, Class<?> parserRestrictionClass, Class<?> parserDefaultValueClass) {
ObjectParameter<Parser> parserParam = new ObjectParameter<Parser>(PARSER_ID, parserRestrictionClass, parserDefaultValueClass);
if(config.grab(parserParam)) {
parser = parserParam.instantiateClass(config);
}
}
}
}