/**
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 Sep 1, 2010
*/
package com.bigdata.bop.engine;
import java.util.Comparator;
/**
* An immutable class capturing the evaluation context of an operator against a
* shard.
*
* @author <a href="mailto:thompsonbry@users.sourceforge.net">Bryan Thompson</a>
* @version $Id$
*/
public class BSBundle implements Comparable<BSBundle> {
public final int bopId;
public final int shardId;
@Override
public String toString() {
return super.toString() + "{bopId=" + bopId + ",shardId=" + shardId
+ "}";
}
public BSBundle(final int bopId, final int shardId) {
this.bopId = bopId;
this.shardId = shardId;
}
@Override
public int hashCode() {
return (bopId * 31) + shardId;
}
@Override
public boolean equals(final Object o) {
if (this == o)
return true;
if (!(o instanceof BSBundle))
return false;
final BSBundle t = (BSBundle) o;
return bopId == t.bopId && shardId == t.shardId;
}
/**
* {@inheritDoc}
* <p>
* This orders the {@link BSBundle}s by reverse {@link #bopId} and by
* {@link #shardId} if the {@link #bopId} is the same. This order imposes a
* bias to draw entries with higher {@link #bopId}s from an ordered
* collection.
* <p>
* Note: Query plans are assigned bopIds from 0 through N where higher
* bopIds are assigned to operators that occur later in the query plan. This
* is not a strict rule, but it is a strong bias. Given that bias and an
* ordered map, this {@link Comparator} will tend to draw from operators
* that are further along in the query plan. This emphasizes getting results
* through the pipeline quickly. Whether or not this {@link Comparator} has
* any effect depends on the {@link ChunkedRunningQuery#consumeChunk()}
* method and the backing map over the operator queues. If a hash map is
* used, then the {@link Comparator} is ignored. If a skip list map is used,
* then the {@link Comparator} will influence the manner in which the
* operator queues are drained.
*/
@Override
public int compareTo(final BSBundle o) {
int ret = (bopId < o.bopId) ? 1 : ((bopId == o.bopId) ? 0 : -1);
if (ret == 0) {
ret = (shardId < o.shardId) ? 1 : ((shardId == o.shardId) ? 0 : -1);
}
return ret;
}
}