/* Copyright (C) SYSTAP, LLC DBA Blazegraph 2006-2016. All rights reserved. Contact: SYSTAP, LLC DBA Blazegraph 2501 Calvert ST NW #106 Washington, DC 20008 licenses@blazegraph.com This program 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; version 2 of the License. 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, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ /* * Created on Oct 10, 2008 */ package com.bigdata.sparse; import com.bigdata.sparse.TPS.TPV; /** * Various constants that may be used with the {@link SparseRowStore}. * * @author <a href="mailto:thompsonbry@users.sourceforge.net">Bryan Thompson</a> * @version $Id$ */ public interface IRowStoreConstants { /** * The minimum value for a timestamp. This may be used as the <i>fromTime</i> * to accept {@link TPV}s beginning with the earliest values on record in * the store. */ public static final long MIN_TIMESTAMP = 1L; /** * The maximum value for a timestamp. This may be used as the <i>toTime</i> * to accept {@link TPV}s up to the most current on record in the store. */ public static final long MAX_TIMESTAMP = Long.MAX_VALUE; /** * A special value that may be used as the <i>toTime</i> to read * <em>only</em> the current values for a given logical row. * <p> * Note: This value MAY NOT be specified for the <i>fromTime</i>. The * <i>fromTime</i> is always the first timestamp that will be accepted by a * read. * <p> * Normally you will specify {@link #MIN_TIMESTAMP} as the <i>fromTime</i> * when you specify {@link #CURRENT_ROW} as the <i>toTime</i>. This has the * effect of returning the most current bindings for all properties in the * logical row. * <p> * If you specify a different <i>fromTime</i> timestamp then any property * not bound since the given <i>fromTime</i> WILL NOT have a binding in the * returned property set. This is useful when you are storing timeseries * data as you can efficiently select a range of the timeseries. */ public static final long CURRENT_ROW = Long.MIN_VALUE; /** * A value which indicates that the timestamp will be assigned by the server - * unique timestamps are NOT guaranteed with this constant. If the server * assigns the same timestamp to two different writes on the same property * values then only one of those property values will be persisted in the * index - the other will be <em>overwritten</em> since it will have * exactly the same key in the index. For this reason, you SHOULD use * {@link #AUTO_TIMESTAMP_UNIQUE} unless you have a compelling reason and a * robust design that is safe in the face of such possible overwrites. * * @see #AUTO_TIMESTAMP_UNIQUE */ public static final long AUTO_TIMESTAMP = -1L; /** * A value which indicates that a unique timestamp will be assigned by the * server. You should use this value rather than {@link #AUTO_TIMESTAMP} * unless you have a compelling design that is robust in the face of * possible overwrite by other callers resulting in the assignment of * the same timestamp to two different writes. * * @see #AUTO_TIMESTAMP */ public static final long AUTO_TIMESTAMP_UNIQUE = -2L; }