/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.jena.sparql.engine.iterator;
import static org.junit.Assert.assertEquals ;
import static org.junit.Assert.assertNotNull ;
import static org.junit.Assert.assertTrue ;
import java.util.ArrayList ;
import java.util.Iterator ;
import java.util.List ;
import java.util.Random ;
import org.apache.jena.atlas.data.DataBagExaminer ;
import org.apache.jena.atlas.io.IndentedWriter ;
import org.apache.jena.datatypes.xsd.XSDDatatype ;
import org.apache.jena.graph.Graph ;
import org.apache.jena.graph.NodeFactory ;
import org.apache.jena.query.ARQ ;
import org.apache.jena.query.Query ;
import org.apache.jena.query.QueryCancelledException ;
import org.apache.jena.query.SortCondition ;
import org.apache.jena.shared.PrefixMapping ;
import org.apache.jena.sparql.ARQNotImplemented ;
import org.apache.jena.sparql.core.DatasetGraph ;
import org.apache.jena.sparql.core.Var ;
import org.apache.jena.sparql.engine.ExecutionContext ;
import org.apache.jena.sparql.engine.QueryIterator ;
import org.apache.jena.sparql.engine.binding.Binding ;
import org.apache.jena.sparql.engine.binding.BindingComparator ;
import org.apache.jena.sparql.engine.binding.BindingFactory ;
import org.apache.jena.sparql.engine.binding.BindingMap ;
import org.apache.jena.sparql.engine.iterator.QueryIterSort ;
import org.apache.jena.sparql.engine.main.OpExecutorFactory ;
import org.apache.jena.sparql.expr.ExprVar ;
import org.apache.jena.sparql.serializer.SerializationContext ;
import org.apache.jena.sparql.util.Context ;
import org.junit.Before ;
import org.junit.Test ;
public class TestQueryIterSort {
private static final String LETTERS = "qwertyuiopasdfghjklzxcvbnmQWERTYUIOPASDFGHJKLZXCVBNM" ;
private Random random ;
private List<Binding> unsorted ;
private BindingComparator comparator ;
private CallbackIterator iterator ;
@Before
public void setup()
{
random = new Random();
Var[] vars = new Var[]{
Var.alloc("1"), Var.alloc("2"), Var.alloc("3"),
Var.alloc("4"), Var.alloc("5"), Var.alloc("6"),
Var.alloc("7"), Var.alloc("8"), Var.alloc("9"), Var.alloc("0")
};
unsorted = new ArrayList<>();
for(int i = 0; i < 500; i++){
unsorted.add(randomBinding(vars));
}
List<SortCondition> conditions = new ArrayList<>();
conditions.add(new SortCondition(new ExprVar("8"), Query.ORDER_ASCENDING));
comparator = new BindingComparator(conditions);
iterator = new CallbackIterator(unsorted.iterator(), 25, null);
iterator.setCallback(new Callback() {
@Override
public void call() { throw new QueryCancelledException() ; }
});
}
@Test
public void testNoSpill()
{
iterator.setCallback(new Callback() { @Override
public void call() { /* do nothing */ } });
assertEquals(0, iterator.getReturnedElementCount());
Context context = new Context() ;
ExecutionContext executionContext = new ExecutionContext(context, (Graph)null, (DatasetGraph)null, (OpExecutorFactory)null) ;
QueryIterSort qIter = new QueryIterSort(iterator, comparator, executionContext) ;
try
{
assertEquals(0, iterator.getReturnedElementCount()) ;
assertEquals(0, DataBagExaminer.countTemporaryFiles(qIter.db)) ;
qIter.hasNext() ;
assertEquals(500, iterator.getReturnedElementCount()) ;
assertEquals(0, DataBagExaminer.countTemporaryFiles(qIter.db)) ;
}
finally
{
qIter.close() ;
}
}
@Test
public void testCleanAfterClose()
{
iterator.setCallback(()->{}); // Do nothing.
assertEquals(0, iterator.getReturnedElementCount());
Context context = new Context() ;
context.set(ARQ.spillToDiskThreshold, 10L) ;
ExecutionContext executionContext = new ExecutionContext(context, (Graph)null, (DatasetGraph)null, (OpExecutorFactory)null) ;
QueryIterSort qIter = new QueryIterSort(iterator, comparator, executionContext) ;
try
{
assertEquals(0, iterator.getReturnedElementCount()) ;
assertEquals(0, DataBagExaminer.countTemporaryFiles(qIter.db)) ;
qIter.hasNext() ;
assertEquals(500, iterator.getReturnedElementCount()) ;
assertEquals(49, DataBagExaminer.countTemporaryFiles(qIter.db)) ;
}
finally
{
qIter.close() ;
}
assertEquals(0, DataBagExaminer.countTemporaryFiles(qIter.db)) ;
}
@Test
public void testCleanAfterExhaustion()
{
iterator.setCallback(new Callback() { @Override
public void call() { /* do nothing */ } });
assertEquals(0, iterator.getReturnedElementCount());
Context context = new Context() ;
context.set(ARQ.spillToDiskThreshold, 10L) ;
ExecutionContext executionContext = new ExecutionContext(context, (Graph)null, (DatasetGraph)null, (OpExecutorFactory)null) ;
QueryIterSort qIter = new QueryIterSort(iterator, comparator, executionContext) ;
// Usually qIter should be in a try/finally block, but we are testing the case that the user forgot to do that.
// As a failsafe, QueryIteratorBase should close it when the iterator is exhausted.
assertEquals(0, iterator.getReturnedElementCount()) ;
assertEquals(0, DataBagExaminer.countTemporaryFiles(qIter.db)) ;
qIter.hasNext() ;
assertEquals(500, iterator.getReturnedElementCount()) ;
assertEquals(49, DataBagExaminer.countTemporaryFiles(qIter.db)) ;
while (qIter.hasNext())
qIter.next();
assertEquals(0, DataBagExaminer.countTemporaryFiles(qIter.db)) ;
qIter.close() ;
}
@Test(expected=QueryCancelledException.class)
public void testCancelInterruptsInitialisation()
{
assertEquals(0, iterator.getReturnedElementCount());
Context context = new Context() ;
context.set(ARQ.spillToDiskThreshold, 10L) ;
ExecutionContext executionContext = new ExecutionContext(context, (Graph)null, (DatasetGraph)null, (OpExecutorFactory)null) ;
QueryIterSort qIter = new QueryIterSort(iterator, comparator, executionContext) ;
try
{
assertEquals(0, iterator.getReturnedElementCount()) ;
assertEquals(0, DataBagExaminer.countTemporaryFiles(qIter.db)) ;
qIter.cancel() ;
qIter.hasNext() ; // throws a QueryCancelledException
}
finally
{
assertTrue(iterator.isCanceled()) ;
assertEquals(0, iterator.getReturnedElementCount()) ;
assertEquals(0, DataBagExaminer.countTemporaryFiles(qIter.db));
qIter.close() ;
}
assertEquals(0, DataBagExaminer.countTemporaryFiles(qIter.db)) ;
}
@Test(expected=QueryCancelledException.class)
public void testCancelInterruptsExternalSortAfterStartingIteration()
{
assertEquals(0, iterator.getReturnedElementCount());
Context context = new Context() ;
context.set(ARQ.spillToDiskThreshold, 10L) ;
ExecutionContext executionContext = new ExecutionContext(context, (Graph)null, (DatasetGraph)null, (OpExecutorFactory)null) ;
QueryIterSort qIter = new QueryIterSort(iterator, comparator, executionContext) ;
try
{
assertEquals(0, iterator.getReturnedElementCount()) ;
assertEquals(0, DataBagExaminer.countTemporaryFiles(qIter.db)) ;
qIter.hasNext() ; // throws a QueryCancelledException
}
catch ( QueryCancelledException e )
{
// expected
assertEquals(26, iterator.getReturnedElementCount()) ;
// This is zero because QueryIteratorBase will call close() before throwing the QueryCancelledException.
// It does this as a failsafe in case the user doesn't close the QueryIterator themselves.
assertEquals(0, DataBagExaminer.countTemporaryFiles(qIter.db)) ;
throw e ;
}
finally
{
qIter.close() ;
}
assertEquals(0, DataBagExaminer.countTemporaryFiles(qIter.db)) ;
}
@Test(expected=QueryCancelledException.class)
public void testCancelInterruptsExternalSortAtStartOfIteration()
{
iterator = new CallbackIterator(unsorted.iterator(), 25, null);
iterator.setCallback(new Callback() { @Override
public void call() { /* do nothing */ } });
assertEquals(0, iterator.getReturnedElementCount());
Context context = new Context() ;
context.set(ARQ.spillToDiskThreshold, 10L) ;
ExecutionContext executionContext = new ExecutionContext(context, (Graph)null, (DatasetGraph)null, (OpExecutorFactory)null) ;
QueryIterSort qIter = new QueryIterSort(iterator, comparator, executionContext) ;
try
{
assertTrue(qIter.hasNext()) ;
assertEquals(49, DataBagExaminer.countTemporaryFiles(qIter.db));
assertNotNull(qIter.next()) ;
assertTrue(qIter.hasNext()) ;
qIter.cancel() ;
qIter.hasNext() ; // throws a QueryCancelledException
}
finally
{
//assertTrue(iterator.isCanceled()) ;
assertEquals(500, iterator.getReturnedElementCount()) ;
assertEquals(0, DataBagExaminer.countTemporaryFiles(qIter.db));
qIter.close() ;
}
assertEquals(0, DataBagExaminer.countTemporaryFiles(qIter.db)) ;
}
private Binding randomBinding(Var[] vars)
{
BindingMap binding = BindingFactory.create();
binding.add(vars[0], NodeFactory.createBlankNode());
binding.add(vars[1], NodeFactory.createURI(randomURI()));
binding.add(vars[2], NodeFactory.createURI(randomURI()));
binding.add(vars[3], NodeFactory.createLiteral(randomString(20)));
binding.add(vars[4], NodeFactory.createBlankNode());
binding.add(vars[5], NodeFactory.createURI(randomURI()));
binding.add(vars[6], NodeFactory.createURI(randomURI()));
binding.add(vars[7], NodeFactory.createLiteral(randomString(5)));
binding.add(vars[8], NodeFactory.createLiteral("" + random.nextInt(), XSDDatatype.XSDinteger));
binding.add(vars[9], NodeFactory.createBlankNode());
return binding;
}
private String randomURI()
{
return String.format("http://%s.example.com/%s", randomString(10), randomString(10));
}
private String randomString(int length)
{
StringBuilder builder = new StringBuilder();
for(int i = 0; i < length; i++){
builder.append(LETTERS.charAt(random.nextInt(LETTERS.length())));
}
return builder.toString();
}
private class CallbackIterator implements QueryIterator
{
int elementsReturned = 0 ;
Callback callback ;
int trigger ;
Iterator<Binding> delegate ;
boolean canceled = false ;
public CallbackIterator(Iterator<Binding> delegate, int trigger, Callback callback)
{
this.delegate = delegate ;
this.callback = callback ;
this.trigger = trigger ;
}
public void setCallback(Callback callback)
{
this.callback = callback ;
}
@Override
public boolean hasNext()
{
return delegate.hasNext() ;
}
@Override
public Binding next()
{
if (elementsReturned++ >= trigger)
{
callback.call() ;
}
return delegate.next() ;
}
@Override
public void remove()
{
delegate.remove() ;
}
public int getReturnedElementCount()
{
return elementsReturned ;
}
public boolean isCanceled() {
return canceled ;
}
@Override
public Binding nextBinding()
{
if (elementsReturned++ >= trigger) callback.call() ;
return delegate.next() ;
}
@Override
public void cancel() { canceled = true ; }
@Override
public void close() { throw new ARQNotImplemented() ; }
@Override
public void output(IndentedWriter out, SerializationContext sCxt) { throw new ARQNotImplemented() ; }
@Override
public String toString(PrefixMapping pmap) { throw new ARQNotImplemented() ; }
@Override
public void output(IndentedWriter out) { throw new ARQNotImplemented() ; }
}
private interface Callback
{
public void call() ;
}
}