001 /* 002 * JBoss DNA (http://www.jboss.org/dna) 003 * See the COPYRIGHT.txt file distributed with this work for information 004 * regarding copyright ownership. Some portions may be licensed 005 * to Red Hat, Inc. under one or more contributor license agreements. 006 * See the AUTHORS.txt file in the distribution for a full listing of 007 * individual contributors. 008 * 009 * JBoss DNA is free software. Unless otherwise indicated, all code in JBoss DNA 010 * is licensed to you under the terms of the GNU Lesser General Public License as 011 * published by the Free Software Foundation; either version 2.1 of 012 * the License, or (at your option) any later version. 013 * 014 * JBoss DNA is distributed in the hope that it will be useful, 015 * but WITHOUT ANY WARRANTY; without even the implied warranty of 016 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 017 * Lesser General Public License for more details. 018 * 019 * You should have received a copy of the GNU Lesser General Public 020 * License along with this software; if not, write to the Free 021 * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 022 * 02110-1301 USA, or see the FSF site: http://www.fsf.org. 023 */ 024 package org.jboss.dna.connector.federation.merge.strategy; 025 026 import java.util.Iterator; 027 import java.util.List; 028 import java.util.UUID; 029 import net.jcip.annotations.ThreadSafe; 030 import org.jboss.dna.connector.federation.contribution.Contribution; 031 import org.jboss.dna.connector.federation.merge.FederatedNode; 032 import org.jboss.dna.connector.federation.merge.MergePlan; 033 import org.jboss.dna.graph.DnaLexicon; 034 import org.jboss.dna.graph.ExecutionContext; 035 import org.jboss.dna.graph.Location; 036 import org.jboss.dna.graph.property.Path; 037 import org.jboss.dna.graph.property.PathFactory; 038 import org.jboss.dna.graph.property.Property; 039 import org.jboss.dna.graph.property.ValueFormatException; 040 041 /** 042 * A merge strategy that is optimized for merging when there is a single contribution. 043 * 044 * @author Randall Hauch 045 */ 046 @ThreadSafe 047 public class OneContributionMergeStrategy implements MergeStrategy { 048 049 /** 050 * {@inheritDoc} 051 * <p> 052 * This method only uses the one and only one non-null {@link Contribution} in the <code>contributions</code>. 053 * </p> 054 * 055 * @see org.jboss.dna.connector.federation.merge.strategy.MergeStrategy#merge(org.jboss.dna.connector.federation.merge.FederatedNode, 056 * java.util.List, org.jboss.dna.graph.ExecutionContext) 057 */ 058 public void merge( FederatedNode federatedNode, 059 List<Contribution> contributions, 060 ExecutionContext context ) { 061 assert federatedNode != null; 062 assert context != null; 063 assert contributions != null; 064 assert contributions.size() > 0; 065 Contribution contribution = contributions.get(0); 066 assert contribution != null; 067 final PathFactory pathFactory = context.getValueFactories().getPathFactory(); 068 Location location = federatedNode.getActualLocationOfNode(); 069 070 // Copy the children ... 071 Iterator<Location> childIterator = contribution.getChildren(); 072 while (childIterator.hasNext()) { 073 Location child = translateChildFromSourceToRepository(pathFactory, location, childIterator.next()); 074 federatedNode.addChild(child); 075 } 076 077 // Copy the properties ... 078 Property uuidProperty = null; 079 Property dnaUuidProperty = null; 080 Iterator<Property> propertyIterator = contribution.getProperties(); 081 while (propertyIterator.hasNext()) { 082 Property property = propertyIterator.next(); 083 federatedNode.addProperty(property); 084 if (property.isSingle()) { 085 if (property.getName().equals(DnaLexicon.UUID) && hasUuidValue(context, property)) { 086 dnaUuidProperty = property; 087 } else if (property.getName().getLocalName().equals("uuid") && hasUuidValue(context, property)) { 088 uuidProperty = property; 089 } 090 } 091 } 092 if (dnaUuidProperty != null) uuidProperty = dnaUuidProperty; // use "dna:uuid" if there is one 093 094 if (federatedNode.at().getUuid() != null) { 095 federatedNode.setActualLocationOfNode(federatedNode.at()); 096 } else { 097 // Look for the UUID property on the properties, and update the federated node ... 098 if (uuidProperty != null && !uuidProperty.isEmpty()) { 099 UUID uuid = context.getValueFactories().getUuidFactory().create(uuidProperty.getFirstValue()); 100 uuidProperty = context.getPropertyFactory().create(DnaLexicon.UUID, uuid); // Use the "dna:uuid" name 101 federatedNode.setActualLocationOfNode(federatedNode.at().with(uuidProperty)); 102 } else { 103 // Make sure there's a UUID for an identification property ... 104 if (location.getUuid() == null) { 105 location = location.with(UUID.randomUUID()); 106 } 107 // Set the UUID as a property (it wasn't set already) ... 108 uuidProperty = location.getIdProperty(DnaLexicon.UUID); 109 assert uuidProperty != null; // there should be one! 110 federatedNode.addProperty(uuidProperty); 111 federatedNode.setActualLocationOfNode(location); 112 } 113 } 114 115 // Assign the merge plan ... 116 MergePlan mergePlan = MergePlan.create(contributions); 117 federatedNode.setMergePlan(mergePlan); 118 Property mergePlanProperty = context.getPropertyFactory().create(DnaLexicon.MERGE_PLAN, (Object)mergePlan); 119 federatedNode.addProperty(mergePlanProperty); 120 } 121 122 private boolean hasUuidValue( ExecutionContext context, 123 Property property ) { 124 try { 125 context.getValueFactories().getUuidFactory().create(property.getFirstValue()); 126 return true; 127 } catch (ValueFormatException e) { 128 return false; 129 } 130 } 131 132 /** 133 * Utility method to translate the list of locations of the children so that the locations all are correctly relative to 134 * parent location of the federated node. 135 * 136 * @param factory the path factory 137 * @param parent the parent of the child 138 * @param childInSource the child to be translated, with a source-specific location 139 * @return the list of locations of each child 140 */ 141 protected Location translateChildFromSourceToRepository( PathFactory factory, 142 Location parent, 143 Location childInSource ) { 144 // Convert the locations of the children (relative to the source) to be relative to this node 145 Path parentPath = parent.getPath(); 146 if (parentPath == null) return childInSource; 147 Path newPath = factory.create(parentPath, childInSource.getPath().getLastSegment()); 148 return childInSource.with(newPath); 149 } 150 }