package de.lmu.ifi.dbs.elki.database.ids.integer;
/*
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.concurrent.atomic.AtomicInteger;
import de.lmu.ifi.dbs.elki.database.ids.ArrayModifiableDBIDs;
import de.lmu.ifi.dbs.elki.database.ids.DBID;
import de.lmu.ifi.dbs.elki.database.ids.DBIDFactory;
import de.lmu.ifi.dbs.elki.database.ids.DBIDPair;
import de.lmu.ifi.dbs.elki.database.ids.DBIDRange;
import de.lmu.ifi.dbs.elki.database.ids.DBIDs;
import de.lmu.ifi.dbs.elki.database.ids.HashSetModifiableDBIDs;
import de.lmu.ifi.dbs.elki.persistent.ByteBufferSerializer;
import de.lmu.ifi.dbs.elki.persistent.FixedSizeByteBufferSerializer;
import de.lmu.ifi.dbs.elki.utilities.exceptions.AbortException;
/**
* Trivial DBID management, that never reuses IDs and just gives them out in sequence.
* Statically allocated DBID ranges are given positive values,
* Dynamically allocated DBIDs are given negative values.
*
* @author Erich Schubert
*
* @apiviz.landmark
* @apiviz.stereotype factory
* @apiviz.uses IntegerDBID oneway - - «create»
* @apiviz.uses IntegerDBIDPair oneway - - «create»
* @apiviz.uses IntegerDBIDRange oneway - - «create»
* @apiviz.uses TroveArrayModifiableDBIDs oneway - - «create»
* @apiviz.uses TroveHashSetModifiableDBIDs oneway - - «create»
*/
public class TrivialDBIDFactory implements DBIDFactory {
/**
* Keep track of the smallest dynamic DBID offset not used
*/
AtomicInteger next = new AtomicInteger(1);
/**
* Constructor
*/
public TrivialDBIDFactory() {
super();
}
@Override
public DBID generateSingleDBID() {
final int id = next.getAndIncrement();
if (id == Integer.MAX_VALUE) {
throw new AbortException("DBID allocation error - too many objects allocated!");
}
DBID ret = new IntegerDBID(id);
return ret;
}
@Override
public void deallocateSingleDBID(DBID id) {
// ignore.
}
@Override
public DBIDRange generateStaticDBIDRange(int size) {
final int start = next.getAndAdd(size);
if (start > next.get()) {
throw new AbortException("DBID range allocation error - too many objects allocated!");
}
DBIDRange alloc = new IntegerDBIDRange(start, size);
return alloc;
}
@Override
public void deallocateDBIDRange(DBIDRange range) {
// ignore.
}
@Override
public DBID importInteger(int id) {
return new IntegerDBID(id);
}
@Override
public ArrayModifiableDBIDs newArray() {
return new TroveArrayModifiableDBIDs();
}
@Override
public HashSetModifiableDBIDs newHashSet() {
return new TroveHashSetModifiableDBIDs();
}
@Override
public ArrayModifiableDBIDs newArray(int size) {
return new TroveArrayModifiableDBIDs(size);
}
@Override
public HashSetModifiableDBIDs newHashSet(int size) {
return new TroveHashSetModifiableDBIDs(size);
}
@Override
public ArrayModifiableDBIDs newArray(DBIDs existing) {
return new TroveArrayModifiableDBIDs(existing);
}
@Override
public HashSetModifiableDBIDs newHashSet(DBIDs existing) {
return new TroveHashSetModifiableDBIDs(existing);
}
@Override
public DBIDPair makePair(DBID first, DBID second) {
return new IntegerDBIDPair(first.getIntegerID(), second.getIntegerID());
}
@Override
public ByteBufferSerializer<DBID> getDBIDSerializer() {
return IntegerDBID.dynamicSerializer;
}
@Override
public FixedSizeByteBufferSerializer<DBID> getDBIDSerializerStatic() {
return IntegerDBID.staticSerializer;
}
@Override
public Class<? extends DBID> getTypeRestriction() {
return IntegerDBID.class;
}
}