EmptyRepository.java

/*******************************************************************************
 * Copyright (c) 2008, 2010 VMware Inc.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *   VMware Inc. - initial contribution
 *******************************************************************************/

package org.eclipse.virgo.kernel.services.repository.internal;

import java.util.Collections;
import java.util.Map;
import java.util.Set;

import org.eclipse.virgo.repository.Query;
import org.eclipse.virgo.repository.Repository;
import org.eclipse.virgo.repository.RepositoryAwareArtifactDescriptor;
import org.eclipse.virgo.util.osgi.manifest.VersionRange;

/**
 * TODO Document EmptyRepository
 * <p />
 * 
 * <strong>Concurrent Semantics</strong><br />
 * 
 * TODO Document concurrent semantics of EmptyRepository
 * 
 */
public class EmptyRepository implements Repository {

    private static final Query EMPTY_QUERY = new EmptyQuery();

    /**
     * {@inheritDoc}
     */
    public Query createQuery(String key, String value) {
        return EMPTY_QUERY;
    }

    /**
     * {@inheritDoc}
     */
    public Query createQuery(String key, String value, Map<String, Set<String>> properties) {
        return EMPTY_QUERY;
    }

    /**
     * {@inheritDoc}
     */
    public RepositoryAwareArtifactDescriptor get(String type, String name, VersionRange versionRange) {
        return null;
    }

    /**
     * {@inheritDoc}
     */
    public String getName() {
        return "empty";
    }

    /**
     * {@inheritDoc}
     */
    public void stop() {
    }

    private static final class EmptyQuery implements Query {

        /**
         * {@inheritDoc}
         */
        public Query addFilter(String name, String value) {
            return this;
        }

        /**
         * {@inheritDoc}
         */
        public Query addFilter(String name, String value, Map<String, Set<String>> properties) {
            return this;
        }

        /**
         * {@inheritDoc}
         */
         public Query setVersionRangeFilter(VersionRange versionRange) {
             return this;
         }

         /**
          * {@inheritDoc}
          */
         public Query setVersionRangeFilter(VersionRange versionRange, VersionRangeMatchingStrategy strategy) {
             return this;
         }

        /**
         * {@inheritDoc}
         */
        public Set<RepositoryAwareArtifactDescriptor> run() {
            return Collections.<RepositoryAwareArtifactDescriptor> emptySet();
        }
    }
}