001/*
002 * (C) Copyright 2012 Nuxeo SA (http://nuxeo.com/) and others.
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 *     http://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 *
016 * Contributors:
017 *     Thierry Delprat
018 */
019package org.nuxeo.snapshot;
020
021import java.util.Collections;
022import java.util.List;
023
024import org.nuxeo.ecm.core.api.CoreSession;
025import org.nuxeo.ecm.core.api.DocumentModel;
026import org.nuxeo.ecm.core.api.IterableQueryResult;
027import org.nuxeo.ecm.core.event.impl.ShallowDocumentModel;
028import org.nuxeo.ecm.core.query.QueryFilter;
029import org.nuxeo.ecm.core.query.sql.NXQL;
030import org.nuxeo.ecm.core.versioning.OrphanVersionRemovalFilter;
031
032public class SnapshotRemovalPolicy implements OrphanVersionRemovalFilter {
033
034    protected boolean canRemoveVersions(CoreSession session, DocumentModel doc, List<String> uuids) {
035        IterableQueryResult result = null;
036        try {
037            StringBuffer nxql = new StringBuffer("select ecm:uuid from Document where ");
038            nxql.append(SnapshotableAdapter.CHILDREN_PROP + "/* IN (");
039            for (int i = 0; i < uuids.size(); i++) {
040                if (i > 0) {
041                    nxql.append(",");
042                }
043                nxql.append("'" + uuids.get(i) + "'");
044            }
045            nxql.append(")");
046            result = session.queryAndFetch(nxql.toString(), NXQL.NXQL, QueryFilter.EMPTY);
047            if (result.iterator().hasNext()) {
048                return false;
049            }
050            return true;
051        } finally {
052            if (result != null) {
053                result.close();
054            }
055        }
056
057    }
058
059    @SuppressWarnings("unchecked")
060    @Override
061    public List<String> getRemovableVersionIds(CoreSession session, ShallowDocumentModel deletedLiveDoc,
062            List<String> versionUUIDs) {
063
064        if (!canRemoveVersions(session, deletedLiveDoc, versionUUIDs)) {
065            return Collections.emptyList();
066        }
067        return versionUUIDs;
068    }
069}