DedupingInferencerConnection.java
/*******************************************************************************
* Copyright (c) 2015 Eclipse RDF4J contributors, Aduna, and others.
*
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Distribution License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/org/documents/edl-v10.php.
*
* SPDX-License-Identifier: BSD-3-Clause
*******************************************************************************/
package org.eclipse.rdf4j.sail.inferencer.fc;
import java.util.Collections;
import java.util.LinkedHashMap;
import java.util.Map.Entry;
import java.util.Set;
import org.eclipse.rdf4j.model.IRI;
import org.eclipse.rdf4j.model.Resource;
import org.eclipse.rdf4j.model.Statement;
import org.eclipse.rdf4j.model.Value;
import org.eclipse.rdf4j.model.ValueFactory;
import org.eclipse.rdf4j.sail.SailException;
import org.eclipse.rdf4j.sail.inferencer.InferencerConnection;
import org.eclipse.rdf4j.sail.inferencer.InferencerConnectionWrapper;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
public class DedupingInferencerConnection extends InferencerConnectionWrapper {
private static final int MAX_SIZE = 10000;
private static final Logger logger = LoggerFactory.getLogger(DedupingInferencerConnection.class);
private final ValueFactory valueFactory;
private Set<Statement> addedStmts;
private int dedupCount;
public DedupingInferencerConnection(InferencerConnection con, ValueFactory vf) {
super(con);
this.valueFactory = vf;
this.addedStmts = createDedupBuffer();
}
private Set<Statement> createDedupBuffer() {
return Collections.newSetFromMap(new LRUMap<>(MAX_SIZE));
}
@Override
public boolean addInferredStatement(Resource subj, IRI pred, Value obj, Resource... contexts) throws SailException {
if (contexts.length == 0) {
// most inferred statements don't have a context so let's just deal
// with those
Statement stmt = valueFactory.createStatement(subj, pred, obj);
if (addedStmts.add(stmt)) {
return super.addInferredStatement(subj, pred, obj);
} else {
dedupCount++;
return false;
}
} else {
return super.addInferredStatement(subj, pred, obj, contexts);
}
}
@Override
public boolean removeInferredStatement(Resource subj, IRI pred, Value obj, Resource... contexts)
throws SailException {
Statement stmt = valueFactory.createStatement(subj, pred, obj);
addedStmts.remove(stmt);
return super.removeInferredStatement(subj, pred, obj, contexts);
}
@Override
public void clearInferred(Resource... contexts) throws SailException {
resetDedupBuffer();
super.clearInferred(contexts);
}
@Override
public void commit() throws SailException {
super.commit();
logger.debug("Added {} unique statements, deduped {}", addedStmts.size(), dedupCount);
resetDedupBuffer();
}
@Override
public void rollback() throws SailException {
super.rollback();
resetDedupBuffer();
}
private void resetDedupBuffer() {
addedStmts = null; // allow gc before alloc
addedStmts = createDedupBuffer();
dedupCount = 0;
}
static class LRUMap<K, V> extends LinkedHashMap<K, V> {
final int maxSize;
LRUMap(int maxSize) {
super(maxSize, 0.75f, true);
this.maxSize = maxSize;
}
@Override
protected boolean removeEldestEntry(Entry<K, V> entry) {
return size() > maxSize;
}
}
}