/**
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
*/
package com.bigdata.rdf.graph.impl.bd;
import org.openrdf.sail.SailConnection;
import com.bigdata.rdf.graph.IGASContext;
import com.bigdata.rdf.graph.IGASEngine;
import com.bigdata.rdf.graph.IGASState;
import com.bigdata.rdf.graph.IGraphAccessor;
import com.bigdata.rdf.graph.TraversalDirectionEnum;
import com.bigdata.rdf.graph.analytics.BFS;
/**
* Test class for Breadth First Search (BFS) traversal.
*
* @see BFS
*
* @author <a href="mailto:thompsonbry@users.sourceforge.net">Bryan Thompson</a>
*/
public class TestBFS extends AbstractBigdataGraphTestCase {
public TestBFS() {
}
public TestBFS(String name) {
super(name);
}
public void testBFS() throws Exception {
final SmallGraphProblem p = setupSmallGraphProblem();
final IGASEngine gasEngine = getGraphFixture()
.newGASEngine(1/* nthreads */);
try {
final IGraphAccessor graphAccessor = getGraphFixture()
.newGraphAccessor(null/* ignored */);
final IGASContext<BFS.VS, BFS.ES, Void> gasContext = gasEngine
.newGASContext(graphAccessor, new BFS());
final IGASState<BFS.VS, BFS.ES, Void> gasState = gasContext
.getGASState();
// Initialize the froniter.
gasState.setFrontier(gasContext, p.getMike());
// Converge.
gasContext.call();
assertEquals(0, gasState.getState(p.getMike()).depth());
assertEquals(null, gasState.getState(p.getMike()).predecessor());
assertEquals(1, gasState.getState(p.getFoafPerson()).depth());
assertEquals(p.getMike(), gasState.getState(p.getFoafPerson())
.predecessor());
assertEquals(1, gasState.getState(p.getBryan()).depth());
assertEquals(p.getMike(), gasState.getState(p.getBryan())
.predecessor());
assertEquals(2, gasState.getState(p.getMartyn()).depth());
assertEquals(p.getBryan(), gasState.getState(p.getMartyn())
.predecessor());
} finally {
gasEngine.shutdownNow();
}
}
/**
* Variant test in which we choose a vertex (<code>foaf:person</code>) in
* the middle of the graph and insist on forward directed edges. Since the
* edges point from the person to the <code>foaf:person</code> vertex, this
* BSF traversal does not discover any connected vertices.
*/
public void testBFS_directed_forward() throws Exception {
final SmallGraphProblem p = setupSmallGraphProblem();
final IGASEngine gasEngine = getGraphFixture()
.newGASEngine(1/* nthreads */);
try {
final SailConnection cxn = getGraphFixture().getSail()
.getConnection();
try {
final IGraphAccessor graphAccessor = getGraphFixture()
.newGraphAccessor(cxn);
final IGASContext<BFS.VS, BFS.ES, Void> gasContext = gasEngine
.newGASContext(graphAccessor, new BFS());
final IGASState<BFS.VS, BFS.ES, Void> gasState = gasContext
.getGASState();
// Initialize the froniter.
gasState.setFrontier(gasContext, p.getFoafPerson());
// directed traversal.
gasContext
.setTraversalDirection(TraversalDirectionEnum.Forward);
// Converge.
gasContext.call();
// starting vertex at (0,null).
assertEquals(0, gasState.getState(p.getFoafPerson()).depth());
assertEquals(null, gasState.getState(p.getFoafPerson())
.predecessor());
// no other vertices are visited.
assertEquals(-1, gasState.getState(p.getMike()).depth());
assertEquals(null, gasState.getState(p.getMike()).predecessor());
assertEquals(-1, gasState.getState(p.getBryan()).depth());
assertEquals(null, gasState.getState(p.getBryan())
.predecessor());
assertEquals(-1, gasState.getState(p.getMartyn()).depth());
assertEquals(null, gasState.getState(p.getMartyn())
.predecessor());
} finally {
try {
cxn.rollback();
} finally {
cxn.close();
}
}
} finally {
gasEngine.shutdownNow();
}
}
/**
* Variant test in which we choose a vertex (<code>foaf:person</code>) in
* the middle of the graph and insist on reverse directed edges. Since the
* edges point from the person to the <code>foaf:person</code> vertex,
* forward BSF traversal does not discover any connected vertices. However,
* since the traversal direction is reversed, the vertices are all one hop
* away.
*/
public void testBFS_directed_reverse() throws Exception {
final SmallGraphProblem p = setupSmallGraphProblem();
final IGASEngine gasEngine = getGraphFixture()
.newGASEngine(1/* nthreads */);
try {
final SailConnection cxn = getGraphFixture().getSail()
.getConnection();
try {
final IGraphAccessor graphAccessor = getGraphFixture()
.newGraphAccessor(cxn);
final IGASContext<BFS.VS, BFS.ES, Void> gasContext = gasEngine
.newGASContext(graphAccessor, new BFS());
final IGASState<BFS.VS, BFS.ES, Void> gasState = gasContext
.getGASState();
// Initialize the froniter.
gasState.setFrontier(gasContext, p.getFoafPerson());
// directed traversal.
gasContext
.setTraversalDirection(TraversalDirectionEnum.Reverse);
// Converge.
gasContext.call();
// starting vertex at (0,null).
assertEquals(0, gasState.getState(p.getFoafPerson()).depth());
assertEquals(null, gasState.getState(p.getFoafPerson())
.predecessor());
// All other vertices are 1-hop.
assertEquals(1, gasState.getState(p.getMike()).depth());
assertEquals(p.getFoafPerson(), gasState.getState(p.getMike())
.predecessor());
assertEquals(1, gasState.getState(p.getBryan()).depth());
assertEquals(p.getFoafPerson(), gasState.getState(p.getBryan())
.predecessor());
assertEquals(1, gasState.getState(p.getMartyn()).depth());
assertEquals(p.getFoafPerson(), gasState
.getState(p.getMartyn()).predecessor());
} finally {
try {
cxn.rollback();
} finally {
cxn.close();
}
}
} finally {
gasEngine.shutdownNow();
}
}
/**
* Variant test in which we choose a vertex (<code>foaf:person</code>) in
* the middle of the graph and insist on directed edges. Since the edges
* point from the person to the <code>foaf:person</code> vertex, this BSF
* traversal does not discover any connected vertices.
*/
public void testBFS_undirected() throws Exception {
final SmallGraphProblem p = setupSmallGraphProblem();
final IGASEngine gasEngine = getGraphFixture()
.newGASEngine(1/* nthreads */);
try {
final SailConnection cxn = getGraphFixture().getSail()
.getConnection();
try {
final IGraphAccessor graphAccessor = getGraphFixture()
.newGraphAccessor(cxn);
final IGASContext<BFS.VS, BFS.ES, Void> gasContext = gasEngine
.newGASContext(graphAccessor, new BFS());
final IGASState<BFS.VS, BFS.ES, Void> gasState = gasContext
.getGASState();
// Initialize the froniter.
gasState.setFrontier(gasContext, p.getFoafPerson());
// undirected traversal.
gasContext
.setTraversalDirection(TraversalDirectionEnum.Undirected);
// Converge.
gasContext.call();
// starting vertex at (0,null).
assertEquals(0, gasState.getState(p.getFoafPerson()).depth());
assertEquals(null, gasState.getState(p.getFoafPerson())
.predecessor());
// All other vertices are 1-hop.
assertEquals(1, gasState.getState(p.getMike()).depth());
assertEquals(p.getFoafPerson(), gasState.getState(p.getMike())
.predecessor());
assertEquals(1, gasState.getState(p.getBryan()).depth());
assertEquals(p.getFoafPerson(), gasState.getState(p.getBryan())
.predecessor());
assertEquals(1, gasState.getState(p.getMartyn()).depth());
assertEquals(p.getFoafPerson(), gasState
.getState(p.getMartyn()).predecessor());
} finally {
try {
cxn.rollback();
} finally {
cxn.close();
}
}
} finally {
gasEngine.shutdownNow();
}
}
}