| /******************************************************************************* |
| * Copyright (c) 2010, 2017 Cloudsmith Inc. and others. |
| * |
| * This program and the accompanying materials |
| * are made available under the terms of the Eclipse Public License 2.0 |
| * which accompanies this distribution, and is available at |
| * https://www.eclipse.org/legal/epl-2.0/ |
| * |
| * SPDX-License-Identifier: EPL-2.0 |
| * |
| * Contributors: |
| * Cloudsmith Inc. - initial API and implementation |
| *******************************************************************************/ |
| package org.eclipse.equinox.internal.p2.metadata.index; |
| |
| import java.util.*; |
| import org.eclipse.equinox.p2.metadata.expression.IEvaluationContext; |
| import org.eclipse.equinox.p2.metadata.expression.IExpression; |
| import org.eclipse.equinox.p2.metadata.index.IIndex; |
| |
| public class CompoundIndex<T> implements IIndex<T> { |
| |
| private final Collection<IIndex<T>> indexes; |
| |
| public CompoundIndex(Collection<IIndex<T>> indexes) { |
| this.indexes = indexes; |
| } |
| |
| @Override |
| public Iterator<T> getCandidates(IEvaluationContext ctx, IExpression variable, IExpression booleanExpr) { |
| Set<T> result = null; |
| for (IIndex<T> index : indexes) { |
| Iterator<T> indexResult = index.getCandidates(ctx, variable, booleanExpr); |
| if (indexResult == null) |
| return null; |
| if (indexResult.hasNext()) { |
| if (result == null) |
| result = new HashSet<>(); |
| do { |
| result.add(indexResult.next()); |
| } while (indexResult.hasNext()); |
| } |
| } |
| if (result == null) |
| result = Collections.emptySet(); |
| return result.iterator(); |
| } |
| } |