org.argeo.slc.repo/src/org/argeo/slc/repo/core/WorkspaceIndexer.java

   1 /*
   2  * Copyright (C) 2007-2012 Argeo GmbH
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at
   7  *
   8  *         http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16 package org.argeo.slc.repo.core;
  17
  18 import java.util.List;
  19
  20 import javax.jcr.Node;
  21 import javax.jcr.RepositoryException;
  22 import javax.jcr.Session;
  23 import javax.jcr.observation.Event;
  24 import javax.jcr.observation.EventIterator;
  25 import javax.jcr.observation.EventListener;
  26
  27 import org.apache.commons.logging.Log;
  28 import org.apache.commons.logging.LogFactory;
  29 import org.argeo.jcr.JcrUtils;
  30 import org.argeo.slc.SlcException;
  31 import org.argeo.slc.repo.NodeIndexer;
  32
  33 /** Maintains the metadata of a workspace, using listeners */
  34 public class WorkspaceIndexer {
  35         private final static Log log = LogFactory.getLog(WorkspaceIndexer.class);
  36
  37         private final Session adminSession;
  38         private IndexingListener artifactListener;
  39         /** order may be important */
  40         private final List<NodeIndexer> nodeIndexers;
  41
  42         public WorkspaceIndexer(Session adminSession, List<NodeIndexer> nodeIndexers) {
  43                 this.adminSession = adminSession;
  44                 this.nodeIndexers = nodeIndexers;
  45                 try {
  46                         artifactListener = new IndexingListener();
  47                         adminSession
  48                                         .getWorkspace()
  49                                         .getObservationManager()
  50                                         .addEventListener(artifactListener, Event.NODE_ADDED, "/",
  51                                                         true, null, null, true);
  52                 } catch (RepositoryException e) {
  53                         throw new SlcException("Cannot initialize repository backend", e);
  54                 }
  55         }
  56
  57         public void close() {
  58                 try {
  59                         adminSession.getWorkspace().getObservationManager()
  60                                         .removeEventListener(artifactListener);
  61                 } catch (RepositoryException e) {
  62                         log.error("Cannot close workspace indexer "
  63                                         + adminSession.getWorkspace().getName(), e);
  64                 }
  65         }
  66
  67         class IndexingListener implements EventListener {
  68
  69                 public void onEvent(EventIterator events) {
  70                         while (events.hasNext()) {
  71                                 Event event = events.nextEvent();
  72                                 try {
  73                                         String newNodePath = event.getPath();
  74                                         Node newNode = null;
  75                                         for (NodeIndexer nodeIndexer : nodeIndexers) {
  76                                                 try {
  77                                                         if (nodeIndexer.support(newNodePath)) {
  78                                                                 if (newNode == null)
  79                                                                         newNode = adminSession.getNode(newNodePath);
  80                                                                 nodeIndexer.index(newNode);
  81                                                         }
  82                                                 } catch (RuntimeException e) {
  83                                                         e.printStackTrace();
  84                                                         throw e;
  85                                                 }
  86                                         }
  87                                         if (newNode != null)
  88                                                 adminSession.save();
  89                                 } catch (RepositoryException e) {
  90                                         throw new SlcException("Cannot process event " + event, e);
  91                                 } finally {
  92                                         JcrUtils.discardQuietly(adminSession);
  93                                 }
  94                         }
  95                 }
  96         }
  97 }