org.tentackle.dbms.IdSource Maven / Gradle / Ivy
/*
* Tentackle - https://tentackle.org
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
package org.tentackle.dbms;
/**
* Source of ID numbers.
*
* ID-sources are unique instances per session.
* For example, by default there is one ObjectId instance per session.
* However, implementations _may_ be able to be shared among sessions,
* so it's up to the implementation whether it tolerates different
* sessions or not.
*
* @author harald
*/
public interface IdSource {
/**
* Get the next unique ID.
*
* @param db the current session
* @return a free ID.
*/
long nextId(Db db);
/**
* Returns whether retrieving an id is a lock-free operation.
*
* @return true if lock-free
*/
boolean isLockFree();
}