/**
* Copyright (c) 2002-2013 "Neo Technology,"
* Network Engine for Objects in Lund AB [http://neotechnology.com]
*
* This file is part of Neo4j.
*
* Neo4j is free software: you can redistribute it and/or modify
* it under the terms of the GNU 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
package org.neo4j.index.lucene;
import org.neo4j.graphdb.Node;
import org.neo4j.graphdb.PropertyContainer;
import org.neo4j.graphdb.Relationship;
import org.neo4j.graphdb.index.IndexHits;
/**
* A utility for ordering nodes or relationships in a timeline. Entities are added
* to the timeline and then queried given a time period, w/ or w/o lower/upper
* bounds, for example "Give me all entities before this given timestamp" or
* "Give me all nodes between these two timestamps".
*
* Please note that the timestamps don't need to represent actual points in
* time, any <code>long</code> that identifies the indexed {@link Node} or
* {@link Relationship} and defines its global order is fine.
*/
public interface TimelineIndex<T extends PropertyContainer>
{
/**
* @return the last entity in the timeline, that is the entity with the highest
* timestamp or {@code null} if the timeline is empty.
*/
T getLast();
/**
* @return the first entity in the timeline, that is the entity with the lowest
* timestamp or {@code null} if the timeline is empty.
*/
T getFirst();
/**
* Removes an entity from the timeline. The timestamp should be the same
* as when it was added.
*
* @param entity the entity to remove from this timeline.
* @param timestamp the timestamp this entity was added with.
*/
void remove( T entity, long timestamp );
/**
* Adds an entity to this timeline with the given {@code timestamp}.
*
* @param entity the entity to add to this timeline.
* @param timestamp the timestamp to use.
*/
void add( T entity, long timestamp );
/**
* Query the timeline with optional lower/upper bounds and get back
* entities within that range, ordered by date. If {@code reversed} is
* {@code true} the order of the result is reversed.
*
* @param startTimestampOrNull the start timestamp, entities with greater
* timestamp value will be returned (exclusive). Will be ignored if {@code null}.
* @param endTimestampOrNull the end timestamp, entities with lesser timestamp
* @param reversed reverses the result order if {@code true}.
* value will be returned (exclude). Will be ignored if {@code null}.
* @return all entities within the given boundaries in this timeline, ordered
* by timestamp.
*/
IndexHits<T> getBetween( Long startTimestampOrNull, Long endTimestampOrNull, boolean reversed );
/**
* Query the timeline with optional lower/upper bounds and get back
* entities within that range, ordered by date with lowest first.
*
* @param startTimestampOrNull the start timestamp, entities with greater
* timestamp value will be returned (exclusive). Will be ignored if {@code null}.
* @param endTimestampOrNull the end timestamp, entities with lesser timestamp
* value will be returned (exclude). Will be ignored if {@code null}.
* @return all entities within the given boundaries in this timeline, ordered
* by timestamp.
*/
IndexHits<T> getBetween( Long startTimestampOrNull, Long endTimestampOrNull );
}