/*
* 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.core.mem;
import static java.util.EnumSet.noneOf;
import static java.util.Objects.nonNull;
import static java.util.stream.Collectors.toMap;
import static org.apache.jena.sparql.core.mem.QuadTableForm.GSPO ;
import static org.apache.jena.sparql.core.mem.QuadTableForm.SPOG ;
import static org.apache.jena.sparql.core.mem.QuadTableForm.chooseFrom ;
import static org.apache.jena.sparql.core.mem.QuadTableForm.tableForms ;
import static org.apache.jena.sparql.core.mem.TupleSlot.GRAPH ;
import static org.apache.jena.sparql.core.mem.TupleSlot.OBJECT ;
import static org.apache.jena.sparql.core.mem.TupleSlot.PREDICATE ;
import static org.apache.jena.sparql.core.mem.TupleSlot.SUBJECT ;
import java.util.EnumMap;
import java.util.Map;
import java.util.Set;
import java.util.stream.Stream;
import org.apache.jena.graph.Node;
import org.apache.jena.query.ReadWrite;
import org.apache.jena.sparql.core.Quad;
/**
* A six-way {@link QuadTable} using all of the available forms in {@link QuadTableForm}. This class binds together all
* of the enumerated values in {@code enum QuadTableForm}, each of which implements {@link QuadTable}, into one
* implementation of {@code QuadTable} that selects the most useful index form(s) for any given operation.
*
*/
public class HexTable implements QuadTable {
private final Map<QuadTableForm, QuadTable> indexBlock = new EnumMap<QuadTableForm, QuadTable>(
tableForms().collect(toMap(x -> x, QuadTableForm::get)));
/**
* A block of six indexes to which we provide access as though they were one.
*/
protected Map<QuadTableForm, QuadTable> indexBlock() {
return indexBlock;
}
@Override
public Stream<Quad> find(final Node g, final Node s, final Node p, final Node o) {
final Set<TupleSlot> pattern = noneOf(TupleSlot.class);
if (isConcrete(g)) pattern.add(GRAPH);
if (isConcrete(s)) pattern.add(SUBJECT);
if (isConcrete(p)) pattern.add(PREDICATE);
if (isConcrete(o)) pattern.add(OBJECT);
final QuadTableForm choice = chooseFrom(pattern);
return indexBlock().get(choice).find(g, s, p, o);
}
private static boolean isConcrete(final Node n) {
return nonNull(n) && n.isConcrete();
}
@Override
public void add(final Quad q) {
indexBlock().values().forEach(index -> index.add(q));
}
@Override
public void delete(final Quad q) {
indexBlock().values().forEach(index -> index.delete(q));
}
@Override
public Stream<Node> listGraphNodes() {
// GSPO is specially equipped with an efficient listGraphNodes().
return indexBlock().get(GSPO).listGraphNodes();
}
@Override
public Stream<Quad> findInUnionGraph(final Node s, final Node p, final Node o) {
// we can use adjacency in SPOG to solve this problem without building up a set of already-seen triples.
return indexBlock().get(SPOG).findInUnionGraph(s, p, o);
}
@Override
public void begin(final ReadWrite rw) {
indexBlock().values().forEach(table -> table.begin(rw));
}
@Override
public void end() {
indexBlock().values().forEach(QuadTable::end);
}
@Override
public void commit() {
indexBlock().values().forEach(QuadTable::commit);
}
@Override
public void clear() {
indexBlock().values().forEach(QuadTable::clear);
}
}